How to obtain malleable cast iron - Metals and their processing

Graphitizing annealing

/ Theory of heat treatment of metals / Second-order annealing / Annealing of cast irons / Graphitizing annealing

July 22, 2011

White, gray and high-strength (modified) cast irons are subjected to graphitizing annealing.

Annealing of white cast iron into malleable

White cast iron is hard and very brittle due to the large amount of eutectic cementite in its structure. The modern method of producing malleable cast iron by graphitizing white annealing was invented at the beginning of the 19th century.

Currently, malleable cast iron is a widely used engineering material that combines the simplicity and low cost of casting shaped parts with high mechanical properties.

For the production of malleable cast iron, castings from hypoeutectic white cast iron containing 2.2 - 3.1% C are used; 0.7 - 1.5% Si; 0.3 - 1.0% Mn and up to 0.08% Cr. in the charge of silicon, which facilitates graphitization, and manganese and chromium, which hinder it, are adjusted in such a way as to suppress the crystallization of graphite from the melt and ensure the fastest possible passage of graphitization during annealing.

Let us recall that during the crystallization of gray cast iron, graphite grows from the melt in the form of branched crab-shaped rosettes, unfavorable for mechanical properties, the cross-sections of which on the thin section look like curved plates.

Annealing schedule for white cast iron for malleability

Annealing schedule for white cast iron for malleability: I and II - the first
and second stages of graphitization.

When white cast iron is annealed, graphite, called annealing carbon, is formed in a much more compact form that is favorable for mechanical properties. Although malleable cast iron is not forged, its relative elongation is in the range of 2 - 20% (depending on the structure), while for white cast iron the relative elongation does not exceed 0.2%, and for gray cast iron - no more than 1, 2%.

Microstructure of malleable cast iron on a ferritic basis

X120.

The initial phase composition of white cast iron is the same as that of steel - ferrite and cementite, and therefore the mechanism of its austenitization is similar to that discussed in Formation of austenite during heating. When heated, a pearlite-austenitic transformation first occurs, then the dissolution of secondary cementite and homogenization of austenite in C and Si.

First stage of graphitization

During exposure at 900 - 4050 °C, the first stage of graphitization occurs, at the end of which all cementite of eutectic origin and the remains of secondary cementite are replaced by graphite and the structure from austenite-cementite is transformed into austenite-graphite.

The assumption about the decomposition of cementite with the direct release of graphite from it through the reaction Fe3C - 3Fe + C is not consistent with many facts. In particular, the shape of the annealing carbon in ductile iron does not match the shape of the original cementite crystals.

It has been proven that the grafting of white cast iron at the first stage consists of the nucleation of graphite at the A/C boundary and away from cementite crystals and the growth of graphite with the simultaneous dissolution of cementite in austenite by the transfer of carbon atoms through the austenite from the A/C boundary to the A/G boundary.

The specific volume of graphite is several times greater than that of austenite, and therefore its homogeneous nucleation in a dense metal matrix is unlikely - the elastic component ∆Fypr in the formula is too large. Dislocations, subboundaries and high-angle granites are not very effective as sites for heterogeneous graphite nucleation due to the large value of ∆Fypr.

As is known, gray tin, the specific volume of which is one quarter greater than that of white tin, nucleates preferentially on the open surface of a white tin sample. Naturally, during graphitization, when the specific volume of the new phase differs even more sharply from the specific volume of the initial phase, nuclei also predominantly appear on the free surface of austenite.

In the casting volume, places of heterogeneous nucleation of graphite are discontinuities, accumulations of vacancies, shrinkage and gas microvoids, microcracks, breaks at the boundary of austenite with non-metallic inclusions due to the difference in their thermal expansion. The nucleation sites for graphite can be diffusion pores that arise during the homogenization of austenite.

For example, when the composition of austenite is leveled after the departure of silicon atoms from areas enriched with it, an excess of vacancies remains, forming pores. This can presumably explain the acceleration of graphitization under the influence of silicon, which occurs despite the fact that silicon slows down the diffusion of carbon in austenite.

After the formation of graphitization centers in austenite, there is a gradient of carbon concentration, since the limiting solubility of cementite in it is higher than that of graphite (in the state diagram of the Fe - C state diagram, the ES line is located to the right of the E´S´ line). For example, if the first stage of graphitization takes place at temperature t*, then the composition of austenite at the boundary with cementite is represented by point b, and at the boundary with graphite by point a.

Chart area

Section of the phase diagram of Fe - C with solid lines of stable and dashed lines of metastable

equilibrium (scheme).

Equalization of the carbon concentration in austenite makes it unsaturated with respect to cementite (at the A/C boundary, the austenite composition shifts to the left of point b) and supersaturated with respect to graphite (at the A/G boundary, the composition shifts to the right of point a). As a result, cementite continuously dissolves and graphite grows until it disappears.

In addition to the transfer of carbon atoms through a solid solution, another process is necessary for graphitization - the evacuation of iron atoms from the surface of growing graphite in order to free up the “living” space for the graphite. K.P. Bunin proves that it is this diffusion process, and not the influx of carbon atoms, that controls the growth rate of graphite inclusions in austenite, since the diffusion mobility of iron atoms is much less than that of carbon.

The shape of graphite depends on the annealing temperature and the composition of the cast iron. Annealing carbon grows faster along high-angle boundaries and subboundaries, since iron atoms are removed more quickly along them. This undesirable branching of graphite increases with increasing temperature and after annealing at temperatures above 1050 - 1070 ° C, the mechanical properties of cast iron turn out to be very low. This determines the upper temperature limit of the first stage of graphitization.

Additives and impurities have a complex effect on the growth of annealing carbon, changing the diffusion rates of iron and carbon and other parameters. For example, small additions of magnesium (~0.1%) ensure the growth of annealed carbon in a compact form. By adjusting the annealing temperature and the composition of white cast iron, it is possible to obtain malleable cast iron with very compact inclusions of annealed carbon.

When cast iron is cooled after the completion of the first stage of graphitization, the composition of austenite changes along the ES line and secondary graphite is released from it. This stage of graphitization is called intermediate. Secondary graphite is layered on annealed carbon inclusions and usually does not provide an independent structural component.

“Theory of heat treatment of metals”,
I.I. Novikov

Annealing to remove bleach

In thin sections of castings made of gray cast iron and high-strength cast iron with nodular graphite, ledeburite crystallizes due to accelerated cooling, i.e. the cast iron turns white. When casting in a chill mold, the entire surface may turn out to be bleached. To improve machinability and increase ductility, graphitizing annealing is carried out, which eliminates the chill of castings. Since gray and ductile cast iron contain more silicon than

Strengthening heat treatment of gray cast iron is not as widespread as heat treatment of steel. This is explained by the fact that flake graphite, acting as internal cuts, greatly reduces the strength and ductility of the metal base. Therefore, changing its structure during heat treatment does not give a large strengthening effect and is often unprofitable. Heat treatment of gray cast irons with a more favorable form of graphite is more effective, in

Second stage of graphitization

The metal matrix of ductile iron is formed by the eutectoid decomposition of austenite. To obtain a purely ferritic matrix, cooling in the eutectoid decomposition temperature range must be slow (see figure Annealing schedule for white cast iron to ductile iron). Here the second stage of graphitization takes place - austenite decomposes according to the scheme A → F + G. Diagram of isothermal transformations of austenite Diagram of isothermal transformations of austenite into

Source: https://www.ktovdome.ru/teoriya_termicheskoy_obrabotki_materialov/355/82/10957.html

What type of cast iron is ductile iron made from?

Malleable cast iron is obtained by prolonged thermal annealing of white cast iron blanks. As a result of heat treatment, cementite decomposes into iron and carbon in the form of graphite of a compact flake shape.

Material with such graphite inclusions is characterized by high strength parameters, ductility and resistance to impact loads.

Types of cast iron

Cast iron is an alloy of iron and carbon, where the content of the latter is more than 2.14%. The composition of such an alloy may also include other elements. Their content determines many parameters and properties of the material.

The iron-carbon alloy contains cementite, graphite and graphite with cementite. Cementite is a compound of carbon and iron with the composition Fe3C. Graphite is one of the allotropic modifications of carbon with a layered structure.

Depending on the content of these compounds, the color of the product changes. When cementite predominates, the material acquires a light sheen. This is where the name “white” came from.

Graphite has a dark color, which it imparts to castings. It is the structure of graphite inclusions that determines the plastic properties of the material.

Based on this, the alloy is divided into:

grey;
malleable;
high strength;
special purpose.

The first type of materials includes an alloy of iron and carbon in the graphite modification of flake, lamellar or globular shape. It has high casting properties. Thanks to them, it is often used to produce parts of complex shapes.

At the same time, the fragility of the alloy limits its use in products subject to tension or bending. An alloy with globular graphite is characterized by high strength properties. It is classified as one of the subspecies of gray cast iron.

The formation of graphite of the specified form is achieved thanks to the addition of magnesium and cerium. Other forms are obtained due to different cooling rates.

Malleable cast iron contains carbon in the concentration range from 2.4–2.8%. In addition, the alloy may contain: silicon, manganese, sulfur and phosphorus. These elements influence the final properties of products.

Features of the production of malleable cast iron

Shape of graphite inclusions and metal base.

To obtain malleable cast iron, it is necessary to follow a technology based on thermal annealing of workpieces at a certain temperature. As a result of this process, cementite and austenite decompose. Thus, carbon is obtained that crystallizes in flocculent graphite.

Austenite is iron with a face-centered lattice. This modification is high temperature. In iron-carbon steels it can form at temperatures above 727 degrees, and in pure iron at 910 degrees.

The final process of graphite formation occurs at lower temperatures - in the range of 720-760 degrees. It is carbon in this modification that determines such characteristics as the ductility and strength of malleable cast iron.

The method involves heat treatment of malleable cast iron in two stages. First, the material is exposed to temperatures up to 1000 degrees. Holding castings under these conditions leads to the decomposition of ledeburite into graphite and austenite.

After annealing at high temperature, the product is cooled to 720-760 degrees. As a result, pearlite is formed, which further decomposes into ferrite and graphite.

Melting of material for the production of cast iron is carried out in cupola furnaces, flame and electric furnaces. Sometimes this process is carried out in combination furnaces. The original castings may contain varying amounts of carbon.

When producing a ferritic alloy, it is necessary to use workpieces with a lower carbon concentration. Such products have a high melting point and therefore require an increased superheating temperature.

Typically, two furnaces are used for smelting in this situation. Melting occurs in the cupola furnace, and overheating occurs in the electric arc furnace. The described smelting technology is called the duplex process.

For the production of pearlitic alloy, workpieces with a high “C” content are used. A cupola furnace is sufficient to melt such material.

A feature of the production of molds for castings is the increased shrinkage of the white alloy. Because of this process, it becomes necessary to install side profits at each local thickening of the casting. This avoids the formation of shells.

In order to increase the cooling rate of thicker parts of the casting, metal coolers are used.

The influence of carbon and silicon on the structure of cast iron and the dependence of the structure on the thickness of cast iron.

The name of this material is due only to its higher plastic properties. In fact, it cannot be forged. This type of alloy is used in the same way as its other types.

The advantage of malleable cast iron, compared to white cast iron, is its high corrosion resistance. In terms of this property, the material ranks higher than carbon steels. In mechanical properties it is inferior to steel, but superior to white cast iron.

Types of malleable cast iron

Depending on the production process, malleable cast iron is either ferritic or pearlitic. In the first case, production is carried out in a neutral environment. This material has a ferritic structure with residual annealing carbon.

The composition of the alloy before heat treatment includes 2.2-2.99 percent carbon, as well as additives of other elements, the content of which does not exceed one percent. A decrease in the “C” concentration is accompanied by an increase in the strength characteristics of the material. However, its casting properties are reduced.

This material is widely used in the manufacture of parts for machines and agricultural equipment, where resistance to constant loads and stresses is required.

This alloy has lower plastic properties. In this regard, it is used in tasks that do not require resistance to severe plastic and chemical loads.

Properties of malleable cast irons

Malleable cast iron has mechanical properties that depend on the silicon-carbon content in the graphite allotropic modification. For white-core material, chromium and manganese also have an effect.

The difference in the structure of products also determines the difference in properties. Thus, the black-core alloy is characterized by greater ductility, but lower hardness than the pearlite type.

The high strength characteristics of these alloys are provided by flake-shaped graphite. Despite their name, these products cannot be forged. They are made by casting parts into specified shapes.

The main advantage of a malleable alloy is the uniformity of properties across the cross-section of the material, as well as the absence of stress.

In terms of other characteristics they differ:

good fluidity during casting;
absorption of vibrations;
high wear resistance;
good corrosion resistance to moisture and many aggressive chemical compounds;
high resistance to shock loads.

Product marking

Ductile iron grades begin with the letters “KCH” followed by numbers. The first numbers correspond to a tenfold reduction in the tensile strength of the material. The second pair is an indicator of relative elongation.

According to accepted standards, malleable cast irons have eleven types of marking. 4 grades correspond to ferritic, and 7 grades correspond to pearlitic.

Areas of use of the material

Mechanical properties and chemical composition of cast iron.

The use of malleable cast iron was found in mechanical engineering, automotive industry, in the production of railway cars, and in the manufacture of agricultural equipment.

The best properties for the noted applications are the pearlite type. However, despite the higher characteristics, black-heart alloy is more often used. This is due to lower production costs.

Only for the manufacture of parts subject to high loads, white-core material is used. Such products include springs, engine parts, etc.

Bottom line

Malleable cast irons have found wide application in various areas of human activity due to their high strength properties and good corrosion resistance.

They are used for the manufacture of various parts that must withstand significant constant and periodic loads.

Depending on the tasks, either ferritic or pearlitic type of material can be used. Each of them has its own advantages and disadvantages, described in this article.

Source: https://varimtutru.com/iz-kakogo-chuguna-poluchayut-kovkiy-chugun/

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

McGregor tried to throw the same high kick at Khabib.

Conor made an epic comeback: at UFC 246 in Las Vegas, he knocked out Donald Cerrone in 40 seconds. At a press conference after the tournament, promotion president Dana White said that next for McGregor is a fight with Khabib. At the same time, Floyd Mayweather also announced a rematch against the Irishman.

But while everyone is figuring out Conor’s next opponents, Nate Diaz and social networks are raging that the fight against Cowboy has been bought.

But if you carefully reconsider these 40 seconds, there will be less and less reason to agree with Diaz. There is nothing surprising at all in the logic of the battle.

Cerrone said he was nervous before going into the cage – Khabib called it “the mentality of a spectacle guy.” Naturally, before the fight with McGregor, the jitters are even greater. Conor is the most powerful in the first round – this is his strength, Donald’s is his weakness.

Therefore, from the first second the Irishman was discouraging by shortening the distance (it’s hard to expect this from him - he always works at a distance, but here he went into the clinch).

He landed three blows with his shoulders and broke his opponent’s nose.

He broke the distance, blocked the shot and pressed him towards the cage.

At the 20th second he threw a left high kick.

Exactly the same episode happened in the fight with Khabib, only at the 12th second. Conor pressed and threw a kick to the head. The difference is that Nurmagomedov successfully blocked this shot, and Cerrone caught the blow with his jaw.

The knee is absolutely relevant when an opponent is knocked down at the cage. After which Conor comes in from the left - from there it is more difficult to hit him, from there it is more convenient for him to work with his left hand.

Finishing on the ground. Again - accentuated left strikes.

Conor's victory is due to good timing, home preparations and work based on his strengths and his opponent's weaknesses. But, of course, it is much easier to believe in a conspiracy theory.

After all, every victory for Conor is a negotiated deal.

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

They have been talking about buying Conor's fights since 2014 (he joined the UFC in 2013). Then he knocked out a top opponent for the first time, defeating Dustin Poirier in 106 seconds. One fight later, McGregor had a fight for the interim title - against Chad Mendes. And this is the first time that the Irishman began to be suspected not only on social networks.

“This is a fake fight. We're turning into wrestling. I’m very sorry,” Wanderlei Silva said. He promised to provide evidence, but then apologized.

Conor was accused of making an arrangement against a fighter who had only been preparing for 2 weeks and simply came on as a substitute to save the tournament. Arguments: the wrestler Mendes, instead of controlling on the ground, tried to go for a choke, did not destroy McGregor on the ground, and then fell from one blow to the liver.

Everything is true, but:

• Going for submission is an attempt to finish the fight as soon as possible, knowing that you may not have enough functionality in the future, because you have been preparing for two weeks.

• Lack of a large number of strikes on the ground – for the same reason. Wasting energy and dying prematurely?

• Incredible, but true: blows to the liver actually cause people to fall.

After Mendes was Jose Aldo, who fell in 13 seconds. And again the accusations. But is a fighter who dominated the featherweight division for 10 years and heard a lot of crap from his opponent really capable of giving up? And if so, why so - tightly and knockout?

“This fight cannot be fixed. My dad taught me to live honestly. “I will never sell myself,” replied Aldo.

Then Conor finally had a real fight - when he lost to Nate Diaz. If McGregor is defeated, then everything was fair, otherwise, no. True, it is strange that a fighter with a legendary legacy (Aldo) can be bribed, but one who does not care about the record (Diaz) cannot.

Fortunately for Conor, the rematch against Nate reached the judges of the fight, so he won by majority decision. It doesn’t matter at all that he dropped Diaz several times and did not fall himself in the bloody exchanges.

The fight for the lightweight title against Eddie Alvarez is the loudest reason to accuse Conor of an agreement. Too sweet a scenario: McGregor became the first ever simultaneous two-division champion, and Alvarez watched until he was knocked out in the second round.

Indeed, Eddie seemed passive. 12 accurate hits in 8 minutes of battle should supposedly convince of this, but statistics will argue:

• Alvarez threw a total of 46 punches, that is, the accuracy percentage is 26. Every fourth strike on target is not so bad. Plus, the problem isn't just Eddie: Conor isn't the kind of guy who's used to blocking headbutts.

• Conor landed 90 punches (40 landed). That is, he killed his opponent exactly twice with an accuracy percentage of 44. At the same time, McGregor constantly moved forward, even hit counterattacks (dodge-punch), and as a fighter he is faster - because he came from featherweight.

• Of Conor's 90 strikes, 12 were delivered on the ground during finishing moves. That is, at a distance of 78-46 in his favor - and this is not much.

Khabib then wrote that it was a shame for Alvarez and the entire main fight of UFC 205. In October 2018, Nurmagomedov showed how to make the main event and the division champion not ashamed. The main thing is to repeat this in a rematch.

Properties and applications of malleable cast iron

Cast iron is one of the most popular metal alloys. It is used in various spheres of human life. In addition to the main alloy, there are separate varieties of this material, for example, malleable cast iron. Each type of cast iron has its own composition and characteristics.

Main characteristics of the metal

Malleable iron

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Malleable cast iron Malleable cast iron ( 1 vote, average: 5 out of 5)

Malleable cast iron is, in other words, the name of a soft, ductile alloy that is produced by casting white cast iron. The production process also includes annealing in special furnaces for a duration of 20 - 100 hours at a temperature of 950 - 970 degrees Celsius, followed by heat treatment. The production technology of this alloy uses long annealing, during which cementite disintegrates and graphite is formed.

Malleable cast iron has a steel base and contains carbon in the form of graphite. Due to the fact that graphite is in the form of flakes, such cast iron is slightly viscous and ductile. Making malleable iron is not that fast and is quite expensive. Therefore, its use in industry is limited.

Ductile iron grades

Heat treatment of white cast iron (production of malleable cast iron)

White cast iron, due to its high hardness and brittleness, is not widely used. White cast iron products are the starting product for producing malleable cast iron using heat treatment.

For this purpose, white cast iron is used, which contains 2.5-3.2% C, 0.6-0.9% Si, 0.3-0.4% Mn, 0.1-0.2% P and 0 .06—0.1% S.

The initial structure of white cast iron is pearlite and ledeburite.

Malleable iron | Agency Lite++

Malleable iron castings are produced by graphitizing annealing of white cast iron of a certain chemical composition, which ensures the formation of compact graphite during the annealing process, which gives the ductile iron increased mechanical properties (tensile strength σB, elongation δ and impact strength αH).

The recommended chemical composition of malleable cast iron is characterized by a reduced content of graphitizing elements C=2.4-2.9%; Si=1.0-1.6%; C+Si=3.6-4.2%, which is due to the need to obtain castings from malleable iron in a cast state with 100% chill throughout the entire cross-section of the casting, for the simple reason that if there is lamellar graphite in the cast iron structure, in the process Subsequent annealing will result in the formation of flake graphite (i.e., gray cast iron), rather than the compact nature of ductile cast iron.

It is customary to distinguish between black-core malleable cast iron, obtained by graphitizing annealing (technology used in Ukraine) and white-core malleable cast iron, obtained by decarburizing annealing in an oxidizing environment (usually the castings are placed in containers mixed with iron ore, t=1000-1050°C, τ=60- 70 h). Thin-walled castings from white malleable cast iron are produced in France, Germany, Italy and other countries; the main advantages of such cast iron are increased viscosity and suitability for welding without preliminary and subsequent heat treatment.

Heat treatment

Graphitizing annealing is an integral technological operation in the process of producing malleable cast iron. The main purpose is to carry out graphitization, i.e. separation of graphite from cementite, and the process can proceed in two ways: complete graphitization of cementite, producing a ferritic metal matrix, and partial graphitization of primary and ledeburite cementite, producing pearlite or pearlite-ferrite metal matrix.

Regardless of the chosen option, graphitizing annealing is carried out in two stages:

Rice. 1: Scheme of graphitizing annealing of malleable cast iron

the stage includes: heating to a temperature of 930-1050°C at a rate of 200-300°C/h; holding for ~10 hours. At this stage, decomposition of primary and ledeburite cementite occurs, resulting in the formation of an austenite matrix with inclusions of flake (compact) graphite (see Fig. 1). This is followed by a decrease in temperature to ~760°C (at a rate of 50-65°C/h), i.e. to a temperature slightly above the onset of the eutectoid transformation.
the stage involves slow cooling at a rate of no higher than 5°C/h throughout the entire eutectoid transformation range, up to ~700°C. At this stage, the cementite included in the perlite decomposes. The final microstructure of cast iron depends on the parameters of the second stage: short-term exposure (~5 hours) entails the formation of a pearlite structure of the metal matrix with inclusions of compact graphite, around which a ferrite rim is located; long exposure for 20-40 hours leads to the formation of a ferritic metal matrix with inclusions of compact graphite, which is clearly shown in Fig. 1.

The main disadvantage of the technical process for producing malleable cast iron is the lengthy heat treatment process, which, given the current high prices for electricity, leads to significant costs. To reduce the annealing time, malleable cast iron is subjected to modification and microalloying with aluminum (0.01%), boron (0.003%), titanium (0.03%), bismuth (0.003%), which leads to an increase in graphitization centers in the melt and a decrease in the stability of cementite .

Advantages of malleable cast iron:

Combination of high mechanical properties with high cutting machinability (compact graphite contributes to chip brittleness and is a lubricant)
Homogeneous structure over the entire cross-section of the casting
No internal stresses in castings
Ability to withstand high alternating loads
High corrosion resistance

Malleable cast iron is used for the production of small thin-walled castings (3-50 mm) for critical purposes, operating under dynamic alternating loads in the automotive, tractor and agricultural machinery industries for the manufacture of gearboxes, drive mechanism parts, chassis, levers, crankshafts and camshafts, clutch parts , diesel engine pistons, valve rocker arms, fittings, etc.

Standards

Iron production. Cast iron grades. Production technology :

Currently, the main method of producing cast iron is smelting iron ores in blast furnaces. Smelting requires a number of raw materials, such as fluxes, iron or manganese ores, and fuel.

The fuel used is coke, which is essentially coal. The role of coke is to provide the process with reducing energy and a certain amount of heat. Let's look at cast iron production in more detail.

Since this is a complex and lengthy process, its description will take a lot of time.

Fuel for smelting

Graphitizing annealing

/ Theory of heat treatment of metals / Second-order annealing / Annealing of cast irons / Graphitizing annealing

July 22, 2011

White, gray and high-strength (modified) cast irons are subjected to graphitizing annealing.

Annealing of white cast iron into malleable

What type of cast iron is ductile iron made from?

Material with such graphite inclusions is characterized by high strength parameters, ductility and resistance to impact loads.

Types of cast iron

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

McGregor tried to throw the same high kick at Khabib.

But while everyone is figuring out Conor’s next opponents, Nate Diaz and social networks are raging that the fight against Cowboy has been bought.

But if you carefully reconsider these 40 seconds, there will be less and less reason to agree with Diaz. There is nothing surprising at all in the logic of the battle.

Therefore, from the first second the Irishman was discouraging by shortening the distance (it’s hard to expect this from him - he always works at a distance, but here he went into the clinch).

He landed three blows with his shoulders and broke his opponent’s nose.

He broke the distance, blocked the shot and pressed him towards the cage.

At the 20th second he threw a left high kick.

The knee is absolutely relevant when an opponent is knocked down at the cage. After which Conor comes in from the left - from there it is more difficult to hit him, from there it is more convenient for him to work with his left hand.

Finishing on the ground. Again - accentuated left strikes.

Conor's victory is due to good timing, home preparations and work based on his strengths and his opponent's weaknesses. But, of course, it is much easier to believe in a conspiracy theory.

After all, every victory for Conor is a negotiated deal.

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

Properties and applications of malleable cast iron

Main characteristics of the metal

The main characteristics of the metal directly depend on the percentage of carbon in its composition. The structure of malleable cast iron is a crystal lattice containing carbon particles in the form of graphite. Additionally, the composition contains small amounts of silicon, manganese and chromium.

The structure of a malleable material affects the parts and workpieces made from it. For example, the ferritic variety of material has a lower strength index than pearlite. When using flake-shaped graphite particles, the material becomes more durable and ductile. Parts made from ductile iron can change size and shape when exposed to room temperature and humidity levels for long periods of time.

However, the name of the material cannot indicate the processing methods. This type of cast iron, according to the standards specified in GOSTs, is not produced using forging equipment. For this, casting technology is used. Thanks to this, there are no internal or surface stresses in the finished metal. Characteristics:

High fluidity and strength.
Resistance to corrosive processes.
The metal can withstand prolonged exposure to acids and alkalis.

However, the performance of this material quickly deteriorates when exposed to low temperatures. It becomes brittle and is destroyed by impacts.

Varieties

Malleable iron

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Ductile iron grades

The grades of malleable cast iron are classified as follows: KCh30-6, KCh33-8, KCh35-10. The principle of this marking of cast iron alloys is structured as follows: the letters “KCH” mean malleable cast iron , after the letters the first two numbers indicate the tensile strength tolerance, followed by two numbers - elongation, small in tension.

Grades of malleable cast iron are determined according to GOST standards, which contain standardized characteristics for each alloy. The percentage of additives is controlled and set during metal smelting and is indicated in documents, as well as directly on the product itself when preparing it for shipment to the customer.

In some cases, with large volumes of ordered products, some deviations from the established standards are possible if this is required to satisfy the necessary consumer request.

For the convenience of users, some data on individual alloy grades is collected in the following table.

Ductile iron application

Heat treatment of white cast iron (production of malleable cast iron)

White cast iron, due to its high hardness and brittleness, is not widely used. White cast iron products are the starting product for producing malleable cast iron using heat treatment.

For this purpose, white cast iron is used, which contains 2.5-3.2% C, 0.6-0.9% Si, 0.3-0.4% Mn, 0.1-0.2% P and 0 .06—0.1% S.

The initial structure of white cast iron is pearlite and ledeburite.

The ledeburite structure is found in all white cast irons, i.e. in iron-carbon alloys with a carbon content of more than 2%, which is present in the alloy in the form of cementite.

Ledeburite at room temperature is a mechanical mixture of pearlite and cementite.

We remind you that perlite is also a mechanical mixture, but of ferrite and cementite, and perlite is a finer mixture than ledeburite.

The described annealing of malleable cast iron is carried out in a neutral environment (N2 or H2) to protect against decarburization and oxidation, in continuous furnaces specially designed for this purpose.

The parts are placed on special pallets , which are placed on a roller bed.

Pallets are pushed at a certain speed along rollers. The length of the heating chambers of the first and second stages of annealing is determined in such a way that the parts remain in the chambers for the time required for a given temperature.

Annealing of malleable cast iron is carried out according to the regime shown in Fig. 76.

The first stage of annealing aims to decompose cementite, which is part of ledeburite; In perlite, cementite is preserved.
The second stage of annealing aims to decompose cementite, which is part of pearlite.

As a result of passing only one stage of annealing, malleable cast iron with the structure of pearlite + ferrite + carbon annealing is obtained.

Such cast iron is called pearlitic (pearlitic-ferritic, Fig. 77, a).

It has good strength properties, but low ductility. Cast iron with this structure is used in parts subject to bending and friction.

To increase strength, cast iron can be quenched and highly tempered, which improves its mechanical properties.

After a complete annealing cycle, the structure of cast iron consists of ferrite and annealed carbon, i.e. ferritic malleable cast iron is formed (Fig. 77, b).

Malleable cast iron is used to make small parts of complex shapes that are difficult to machine by cutting.

Malleable iron | Agency Lite++

Heat treatment

Regardless of the chosen option, graphitizing annealing is carried out in two stages:

Rice. 1: Scheme of graphitizing annealing of malleable cast iron

the stage includes: heating to a temperature of 930-1050°C at a rate of 200-300°C/h; holding for ~10 hours. At this stage, decomposition of primary and ledeburite cementite occurs, resulting in the formation of an austenite matrix with inclusions of flake (compact) graphite (see Fig. 1). This is followed by a decrease in temperature to ~760°C (at a rate of 50-65°C/h), i.e. to a temperature slightly above the onset of the eutectoid transformation.
the stage involves slow cooling at a rate of no higher than 5°C/h throughout the entire eutectoid transformation range, up to ~700°C. At this stage, the cementite included in the perlite decomposes. The final microstructure of cast iron depends on the parameters of the second stage: short-term exposure (~5 hours) entails the formation of a pearlite structure of the metal matrix with inclusions of compact graphite, around which a ferrite rim is located; long exposure for 20-40 hours leads to the formation of a ferritic metal matrix with inclusions of compact graphite, which is clearly shown in Fig. 1.

Advantages of malleable cast iron:

Combination of high mechanical properties with high cutting machinability (compact graphite contributes to chip brittleness and is a lubricant)
Homogeneous structure over the entire cross-section of the casting
No internal stresses in castings
Ability to withstand high alternating loads
High corrosion resistance

Standards

Technical characteristics of malleable cast iron for the manufacture of castings in Ukraine are regulated by GOST 1215-79 “Ductile iron castings. General technical conditions".

Marking

Iron production. Cast iron grades. Production technology :

Currently, the main method of producing cast iron is smelting iron ores in blast furnaces. Smelting requires a number of raw materials, such as fluxes, iron or manganese ores, and fuel.

The fuel used is coke, which is essentially coal. The role of coke is to provide the process with reducing energy and a certain amount of heat. Let's look at cast iron production in more detail.

Since this is a complex and lengthy process, its description will take a lot of time.

Fuel for smelting

As noted above, coke is used as fuel. But, in addition to this, it is permissible to use fuel oil, coal dust and natural, as well as coke oven gases. Nevertheless, coke is almost always used as the main fuel. This is a substance that is formed when volatile gases are removed from coal at temperatures from 900 to 1,200 degrees.

Today it is the only type of solid fuel that retains its original shape during movement from the furnace to the furnace. In principle, strict requirements are put forward for this material, which relate to mechanical strength and rigidity, which is necessary to withstand large loads in the lower part of the blast furnace. It is extremely important to maintain the coke fraction. Particles that are too small contribute to the gas permeability of the charge, while particles that are too large are destroyed and form a fine fraction.

In addition, it is necessary to maintain a certain percentage of humidity, which is necessary to maintain thermal conditions.

Ores for smelting

Graphitizing annealing

/ Theory of heat treatment of metals / Second-order annealing / Annealing of cast irons / Graphitizing annealing

July 22, 2011

White, gray and high-strength (modified) cast irons are subjected to graphitizing annealing.

Annealing of white cast iron into malleable

Currently, malleable cast iron is a widely used engineering material that combines the simplicity and low cost of casting shaped parts with high mechanical properties.

Annealing schedule for white cast iron for malleability

Annealing schedule for white cast iron for malleability: I and II - the first
and second stages of graphitization.

Microstructure of malleable cast iron on a ferritic basis

X120.

First stage of graphitization

The specific volume of graphite is several times greater than that of austenite, and therefore its homogeneous nucleation in a dense metal matrix is unlikely - the elastic component ∆Fypr in the formula is too large. Dislocations, subboundaries and high-angle granites are not very effective as sites for heterogeneous graphite nucleation due to the large value of ∆Fypr.

After the formation of graphitization centers in austenite, there is a gradient of carbon concentration, since the limiting solubility of cementite in it is higher than that of graphite (in the state diagram of the Fe - C state diagram, the ES line is located to the right of the E´S´ line). For example, if the first stage of graphitization takes place at temperature t*, then the composition of austenite at the boundary with cementite is represented by point b, and at the boundary with graphite by point a.

Chart area

Section of the phase diagram of Fe - C with solid lines of stable and dashed lines of metastable

equilibrium (scheme).

The shape of graphite depends on the annealing temperature and the composition of the cast iron. Annealing carbon grows faster along high-angle boundaries and subboundaries, since iron atoms are removed more quickly along them. This undesirable branching of graphite increases with increasing temperature and after annealing at temperatures above 1050 - 1070 ° C, the mechanical properties of cast iron turn out to be very low. This determines the upper temperature limit of the first stage of graphitization.

“Theory of heat treatment of metals”,
I.I. Novikov

Annealing to remove bleach

Second stage of graphitization

The metal matrix of ductile iron is formed by the eutectoid decomposition of austenite. To obtain a purely ferritic matrix, cooling in the eutectoid decomposition temperature range must be slow (see figure Annealing schedule for white cast iron to ductile iron). Here the second stage of graphitization takes place - austenite decomposes according to the scheme A → F + G. Diagram of isothermal transformations of austenite Diagram of isothermal transformations of austenite into

Source: https://www.ktovdome.ru/teoriya_termicheskoy_obrabotki_materialov/355/82/10957.html

What type of cast iron is ductile iron made from?

Material with such graphite inclusions is characterized by high strength parameters, ductility and resistance to impact loads.

Types of cast iron

Depending on the content of these compounds, the color of the product changes. When cementite predominates, the material acquires a light sheen. This is where the name “white” came from.

Graphite has a dark color, which it imparts to castings. It is the structure of graphite inclusions that determines the plastic properties of the material.

Based on this, the alloy is divided into:

grey;
malleable;
high strength;
special purpose.

The formation of graphite of the specified form is achieved thanks to the addition of magnesium and cerium. Other forms are obtained due to different cooling rates.

Features of the production of malleable cast iron

Shape of graphite inclusions and metal base.

Austenite is iron with a face-centered lattice. This modification is high temperature. In iron-carbon steels it can form at temperatures above 727 degrees, and in pure iron at 910 degrees.

After annealing at high temperature, the product is cooled to 720-760 degrees. As a result, pearlite is formed, which further decomposes into ferrite and graphite.

When producing a ferritic alloy, it is necessary to use workpieces with a lower carbon concentration. Such products have a high melting point and therefore require an increased superheating temperature.

For the production of pearlitic alloy, workpieces with a high “C” content are used. A cupola furnace is sufficient to melt such material.

In order to increase the cooling rate of thicker parts of the casting, metal coolers are used.

The influence of carbon and silicon on the structure of cast iron and the dependence of the structure on the thickness of cast iron.

The name of this material is due only to its higher plastic properties. In fact, it cannot be forged. This type of alloy is used in the same way as its other types.

Types of malleable cast iron

This material is widely used in the manufacture of parts for machines and agricultural equipment, where resistance to constant loads and stresses is required.

This alloy has lower plastic properties. In this regard, it is used in tasks that do not require resistance to severe plastic and chemical loads.

Properties of malleable cast irons

Malleable cast iron has mechanical properties that depend on the silicon-carbon content in the graphite allotropic modification. For white-core material, chromium and manganese also have an effect.

The difference in the structure of products also determines the difference in properties. Thus, the black-core alloy is characterized by greater ductility, but lower hardness than the pearlite type.

The high strength characteristics of these alloys are provided by flake-shaped graphite. Despite their name, these products cannot be forged. They are made by casting parts into specified shapes.

The main advantage of a malleable alloy is the uniformity of properties across the cross-section of the material, as well as the absence of stress.

In terms of other characteristics they differ:

good fluidity during casting;
absorption of vibrations;
high wear resistance;
good corrosion resistance to moisture and many aggressive chemical compounds;
high resistance to shock loads.

Product marking

According to accepted standards, malleable cast irons have eleven types of marking. 4 grades correspond to ferritic, and 7 grades correspond to pearlitic.

Areas of use of the material

Mechanical properties and chemical composition of cast iron.

The use of malleable cast iron was found in mechanical engineering, automotive industry, in the production of railway cars, and in the manufacture of agricultural equipment.

The best properties for the noted applications are the pearlite type. However, despite the higher characteristics, black-heart alloy is more often used. This is due to lower production costs.

Only for the manufacture of parts subject to high loads, white-core material is used. Such products include springs, engine parts, etc.

Bottom line

Malleable cast irons have found wide application in various areas of human activity due to their high strength properties and good corrosion resistance.

They are used for the manufacture of various parts that must withstand significant constant and periodic loads.

Depending on the tasks, either ferritic or pearlitic type of material can be used. Each of them has its own advantages and disadvantages, described in this article.

Source: https://varimtutru.com/iz-kakogo-chuguna-poluchayut-kovkiy-chugun/

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

McGregor tried to throw the same high kick at Khabib.

But while everyone is figuring out Conor’s next opponents, Nate Diaz and social networks are raging that the fight against Cowboy has been bought.

But if you carefully reconsider these 40 seconds, there will be less and less reason to agree with Diaz. There is nothing surprising at all in the logic of the battle.

Therefore, from the first second the Irishman was discouraging by shortening the distance (it’s hard to expect this from him - he always works at a distance, but here he went into the clinch).

He landed three blows with his shoulders and broke his opponent’s nose.

He broke the distance, blocked the shot and pressed him towards the cage.

At the 20th second he threw a left high kick.

The knee is absolutely relevant when an opponent is knocked down at the cage. After which Conor comes in from the left - from there it is more difficult to hit him, from there it is more convenient for him to work with his left hand.

Finishing on the ground. Again - accentuated left strikes.

Conor's victory is due to good timing, home preparations and work based on his strengths and his opponent's weaknesses. But, of course, it is much easier to believe in a conspiracy theory.

After all, every victory for Conor is a negotiated deal.

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

“This is a fake fight. We're turning into wrestling. I’m very sorry,” Wanderlei Silva said. He promised to provide evidence, but then apologized.

Everything is true, but:

• Going for submission is an attempt to finish the fight as soon as possible, knowing that you may not have enough functionality in the future, because you have been preparing for two weeks.

• Lack of a large number of strikes on the ground – for the same reason. Wasting energy and dying prematurely?

• Incredible, but true: blows to the liver actually cause people to fall.

“This fight cannot be fixed. My dad taught me to live honestly. “I will never sell myself,” replied Aldo.

Then Conor finally had a real fight - when he lost to Nate Diaz. If McGregor is defeated, then everything was fair, otherwise, no. True, it is strange that a fighter with a legendary legacy (Aldo) can be bribed, but one who does not care about the record (Diaz) cannot.

Indeed, Eddie seemed passive. 12 accurate hits in 8 minutes of battle should supposedly convince of this, but statistics will argue:

THIS IS INTERESTING: What does not react with copper

• Of Conor's 90 strikes, 12 were delivered on the ground during finishing moves. That is, at a distance of 78-46 in his favor - and this is not much.

Source: `https://www.sports.ru/tribuna/blogs/mmardoboi/2701530.html`

Properties and applications of malleable cast iron

Main characteristics of the metal

High fluidity and strength.
Resistance to corrosive processes.
The metal can withstand prolonged exposure to acids and alkalis.

However, the performance of this material quickly deteriorates when exposed to low temperatures. It becomes brittle and is destroyed by impacts.

Varieties

In the production of high-strength cast iron alloys, different conditions are created under which the annealing procedure is carried out. Depending on changes in the technological process, three types of malleable cast iron are obtained:

Pearlitic - this material contains flake-shaped graphite particles.
Ferritic - This material includes ferrite and flake-shaped carbon particles.
Ferritic-pearlitic. A mixture of the two previous types of malleable cast iron.

Depending on the annealing temperature and alloying additives, the characteristics of the finished material change.

Properties

The mechanical properties of cast iron directly depend on how much carbon it contains and in what form this component is presented. Characteristics may vary due to the addition of alloying impurities. These include silicon, manganese, sulfur, phosphorus and chromium. This material is made from white cast iron after annealing at high temperatures. Properties of malleable material:

High strength and ductility.
Good viscosity.
The material has high wear resistance.

Ductile iron is the best type of base alloy. Massive structures are made from it, the individual parts of which are connected using welding equipment.

Marking

Like other metals or their alloys, malleable cast iron has a certain marking. It is abbreviated as KCH. After the letters indicating the material there are numbers. The first two indicate tensile strength. The third number indicates the elongation rate as a percentage.

According to GOST 1215–79, there are 11 varieties of malleable cast iron, which have their own markings. They can be found in reference books on casting metals and alloys or tables on the Internet.

Production Features

There are a number of features and subtleties in the manufacture of malleable cast iron. First of all, you need to understand that the basis for the manufacture of this material is BC (white cast iron). This alloy has poor casting properties. When cooling, a shrinkage process occurs, during which the material loses a lot in size. During the casting of white cast iron, defects often form, due to which the workpieces are rejected.

To achieve the desired result and circumvent all the disadvantages of this material, it is necessary to heat it to critical temperatures and at the same time take into account how much the shape of the workpiece will change during the simmering and shrinkage processes. The metal should be simmered at a temperature of 1400 degrees Celsius. During this process, the workpieces are placed in special pots made of refractory metals. Up to 300 castings can be placed in one simmering container.

When placing blanks in pots, they are placed as close to each other as possible. They are covered with ore or sand on top. In this way, the material is protected from oxidation and deformation processes.

To make malleable cast iron, electric furnaces are used. Special equipment allows you to regulate the simmering temperature. The most efficient ovens are those in which the air mixture can be controlled. The most popular furnaces for the production of malleable materials are muffle furnaces. They allow you to protect containers with workpieces from contact with fuel combustion products.

Finished castings undergo several stages of cleaning. At the first stage, the remaining molding sand is removed from them. Industrial sandblasting equipment is used to carry out rough cleaning. Next comes the second cleaning stage, in which feeder residues are removed from the casting. Grinding machines are used for this.

GOSTs specify requirements and rules that make it possible to protect parts made from composite parts from the appearance of various defects. These may include cracks, chips, underfills and sinkholes. Forging of cast iron is not carried out at any stage of production. It is impossible to correct most defects by heat treatment.

Areas of use

Due to its characteristics, malleable cast iron is widely used in various industries:

Production of products and parts that will be subject to severe loads during operation.
Mechanical engineering.
Agricultural industry.
Manufacturing of parts for industrial equipment and machine tools.

Malleable cast iron is used to make mechanisms, structures and parts that are used in the operation of railway transport. A striking example of the use of this material in mechanical engineering is the manufacture of crankshafts that are installed in diesel tractors and cars. The low price and characteristics of this metal allow it to be used as an analogue to various types of steel.

Malleable cast iron is an alloy of iron and carbon. It is made from warheads through the annealing process. The result is a unique material with its own characteristics. Used in mechanical engineering, construction, production of parts for trains and wear-resistant equipment, machine tools.

Source: https://metalloy.ru/splavy/kovkij-chugun

Malleable iron

Kashtanovy lane 8/14 51100 Magdalinovka village

Nikolaenko Dmitrij

Malleable cast iron Malleable cast iron ( 1 vote, average: 5 out of 5)

Ductile iron grades

In some cases, with large volumes of ordered products, some deviations from the established standards are possible if this is required to satisfy the necessary consumer request.

For the convenience of users, some data on individual alloy grades is collected in the following table.

Ductile iron application

Malleable cast iron has found application in various industries, although it is not produced in such volumes as alloyed or foundry cast iron. The alloy is mainly used to produce thin-walled castings. Used in various branches of mechanical engineering. This is very practical because the mechanical properties of ductile iron casting are quite high.

For example, regular consumers of this alloy are such industries as the automotive industry, tractor manufacturing, agricultural machinery, electrical industry, machine tool building, and heavy engineering.

Malleable cast iron has found application in these industries due to its good mechanical properties, high ability to withstand impact loads, good wear resistance and the ability to produce it in sufficient quantities, although it has a relatively high cost.

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Source: https://metallsmaster.ru/kovkij-chugun/

Heat treatment of white cast iron (production of malleable cast iron)

White cast iron, due to its high hardness and brittleness, is not widely used. White cast iron products are the starting product for producing malleable cast iron using heat treatment.

For this purpose, white cast iron is used, which contains 2.5-3.2% C, 0.6-0.9% Si, 0.3-0.4% Mn, 0.1-0.2% P and 0 .06—0.1% S.

The initial structure of white cast iron is pearlite and ledeburite.

The ledeburite structure is found in all white cast irons, i.e. in iron-carbon alloys with a carbon content of more than 2%, which is present in the alloy in the form of cementite.

Ledeburite at room temperature is a mechanical mixture of pearlite and cementite.

We remind you that perlite is also a mechanical mixture, but of ferrite and cementite, and perlite is a finer mixture than ledeburite.

The parts are placed on special pallets , which are placed on a roller bed.

Annealing of malleable cast iron is carried out according to the regime shown in Fig. 76.

The first stage of annealing aims to decompose cementite, which is part of ledeburite; In perlite, cementite is preserved.
The second stage of annealing aims to decompose cementite, which is part of pearlite.

As a result of passing only one stage of annealing, malleable cast iron with the structure of pearlite + ferrite + carbon annealing is obtained.

Such cast iron is called pearlitic (pearlitic-ferritic, Fig. 77, a).

It has good strength properties, but low ductility. Cast iron with this structure is used in parts subject to bending and friction.

To increase strength, cast iron can be quenched and highly tempered, which improves its mechanical properties.

After a complete annealing cycle, the structure of cast iron consists of ferrite and annealed carbon, i.e. ferritic malleable cast iron is formed (Fig. 77, b).

Malleable cast iron is used to make small parts of complex shapes that are difficult to machine by cutting.

Such parts are well cast from white cast iron, and subsequent heat treatment provides them with good plastic and strength properties.

Another method of producing malleable cast iron is also used.

Heating of products is carried out in an oxidizing environment, as a result of which carbon burns out from the surface, causing a decrease in hardness and a slight increase in plastic properties, as well as an improvement in workability.

In the center, such cast iron retains the structure of white cast iron. The cast iron obtained by this method is called white-core, in contrast to black-core, obtained by annealing in a neutral environment according to the method described above.

With this method, white cast iron parts are loaded into boxes, sprinkled with scale or ore and heated in conventional chamber furnaces.

Annealing ductile iron is a very time-consuming operation. Currently, many methods have been developed for accelerated annealing of malleable cast iron - preliminary hardening, annealing in molten salts at very high temperatures of 1050-1100°, etc.

All these measures reduce the duration of annealing for malleable cast iron.

Source: http://www.Conatem.ru/tehnologiya_metallov/termicheskaya-obrabotka-belogo-chuguna-poluchenie-kovkogo-chuguna.html

Malleable iron | Agency Lite++

Heat treatment

Regardless of the chosen option, graphitizing annealing is carried out in two stages:

Rice. 1: Scheme of graphitizing annealing of malleable cast iron

the stage includes: heating to a temperature of 930-1050°C at a rate of 200-300°C/h; holding for ~10 hours. At this stage, decomposition of primary and ledeburite cementite occurs, resulting in the formation of an austenite matrix with inclusions of flake (compact) graphite (see Fig. 1). This is followed by a decrease in temperature to ~760°C (at a rate of 50-65°C/h), i.e. to a temperature slightly above the onset of the eutectoid transformation.
the stage involves slow cooling at a rate of no higher than 5°C/h throughout the entire eutectoid transformation range, up to ~700°C. At this stage, the cementite included in the perlite decomposes. The final microstructure of cast iron depends on the parameters of the second stage: short-term exposure (~5 hours) entails the formation of a pearlite structure of the metal matrix with inclusions of compact graphite, around which a ferrite rim is located; long exposure for 20-40 hours leads to the formation of a ferritic metal matrix with inclusions of compact graphite, which is clearly shown in Fig. 1.

Advantages of malleable cast iron:

Combination of high mechanical properties with high cutting machinability (compact graphite contributes to chip brittleness and is a lubricant)
Homogeneous structure over the entire cross-section of the casting
No internal stresses in castings
Ability to withstand high alternating loads
High corrosion resistance

Standards

Technical characteristics of malleable cast iron for the manufacture of castings in Ukraine are regulated by GOST 1215-79 “Ductile iron castings. General technical conditions".

Marking

Malleable cast iron is marked with the letters KCH, followed by two numbers indicating the tensile strength σB (in kgf/mm2), and after them, separated by a hyphen, followed by one or two numbers displaying the relative elongation δ (in %), ending with a hyphen markings with the letters F or P, indicating the class of cast iron: ferritic or pearlitic. For example, KCh 37-12-F means malleable cast iron of the ferritic class with a tensile strength of at least 37 kg/mm2 and a relative elongation of at least 12%.

Classification of malleable cast iron

Depending on the microstructure of the metal matrix, ductile cast iron is divided into ferritic (F) and pearlitic (P):

Malleable cast iron of the ferritic class with a ferritic or ferrite-pearlite microstructure of the metal matrix is produced in the following grades: KCh 30-6, KCh 33-8, KCh 35-10, KCh 37-12
Malleable cast iron of the pearlitic class with a pearlitic microstructure of the metal matrix is produced in the following grades: KCh 45-7, KCh 50-5, KCh 55-4, KCh 60-3, KCh 65-3, KCh 70-2, KCh 80-1.5

Mechanical properties

The mechanical properties of the material of castings made of malleable cast iron of ferritic and pearlitic classes must meet the requirements of GOST 1215-79 given in table. 1.

Table 1: Mechanical properties of ductile cast iron according to GOST 1215-79

Brand	Tensile strength, MPa, (kgf/mm2)	Relative extension, %	Brinell hardness, HB
no less
CC 30-6	294 (30)	6	100-163
CC 33-8	323 (33)	8	100-163
CC 35-10	333 (35)	10	100-163
CC 37-12	362 (37)	12	110-163
CC 45-7	441 (45)	7*	150-207
CC 50-5	490 (50)	5*	170-230
CC 55-4	539 (55)	4*	192-241
CC 60-3	588 (60)	3	200-269
CC 65-3	637 (65)	3	212-269
CC 70-2	686 (70)	2	241-285
CC 80-1.5	784 (80)	1,5	270-320

Note: * By agreement between the manufacturer and the consumer, a reduction of 1% is allowed.

Chemical composition

The recommended chemical composition of malleable cast iron according to GOST 1215-79 is given in table. 2.

Table 2: Chemical composition of malleable cast iron according to GOST 1215-79

Brand	Mass fraction, %
Main components	Impurities, no more
C	Si	C+Si	Mn	P	S	Cr
Ferritic grade
CC 30-6	2,6-2,9	1,0-1,6	3,7-4,2	0,4-0,6	0,18	0,20	0,08
CC 33-8	2,6-2,9	1,0-1,6	3,7-4,2	0,4-0,6	0,18	0,20	0,08
CC 35-10	2,5-2,8	1,1-1,3	3,6-4,0	0,3-0,6	0,12	0,20	0,06
CC 37-12	2,4-2,7	1,2-1,4	3,6-4,0	0,2-0,4	0,12	0,06	0,06
Pearlite class
CC 45-7	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 50-5	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 55-4	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 60-3	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 65-3	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08
CC 70-2	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08
CC 80-1.5	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08

Ductile Iron Casting Manufacturers

Literature

Mechanical and technological properties of metals. Directory. Bobylev A.V. M., “Metallurgy”, 1980. 296 p.
Vozdvizhensky V.M. and others. Foundry alloys and technology of their smelting in mechanical engineering. - M.: Mashinostroenie, 1984. - 432 pp., illus.
Mogilev V.K., Lev O.I. Foundryman's Handbook. M. Mechanical Engineering, 1988. - 272 pp.: ill.
Encyclopedia of Inorganic Materials. In two volumes. K.: Higher School, 1977.
GOST 1215-79 “Ductile iron castings. General technical conditions".
Kolachev B.F., Livanov V.A., Elagin V.I. Metallurgy and heat treatment of non-ferrous metals and alloys Ed. 2nd, rev. and additional M.: Metallurgy, 1981. 416 p.
Handbook of iron casting./Ed. Dr. Tech. Sciences N.G. Girshovich.- L.: Mechanical Engineering. Leningr. department, 1978.- 758 pp., illus.

Source: https://on-v.com.ua/novosti/texnologii-i-nauka/kovkij-chugun/

Iron production. Cast iron grades. Production technology :

Currently, the main method of producing cast iron is smelting iron ores in blast furnaces. Smelting requires a number of raw materials, such as fluxes, iron or manganese ores, and fuel.

The fuel used is coke, which is essentially coal. The role of coke is to provide the process with reducing energy and a certain amount of heat. Let's look at cast iron production in more detail.

Since this is a complex and lengthy process, its description will take a lot of time.

Fuel for smelting

In addition, it is necessary to maintain a certain percentage of humidity, which is necessary to maintain thermal conditions.

Ores for smelting

There is quite a lot of iron in the earth's crust, but it is not found in its pure form; it is always mined with rocks in the form of various compounds. Iron ore can be called only those rocks from which it is economically profitable to extract iron by smelting in a furnace.

In nature, there are rich and poor iron ores. Speaking from the point of view of the metallurgical industry, the ore contains a number of useful additives that are necessary when producing cast iron - chromium, nickel, manganese and others. There are also harmful inclusions: sulfur, phosphorus, copper, etc.

In addition, iron ore can be divided into several groups depending on the mineral:

red iron ore – 70% iron, 30% oxygen;
magnetic iron ore – 72.4% iron, 27.6% oxygen;
brown iron ore – up to 60% iron;
spar iron ore – up to 48.3% iron.

It would be logical to conclude that blast furnace production of pig iron should involve the use of ore from the second group. But the first one is the most common, which is why it is used more often.

Preparing ore for smelting

You cannot extract iron ore from the ground and immediately throw it into the loading device of a blast furnace. First, it is necessary to somewhat improve the technical and economic indicators, which will make it possible to use relatively poor ores, of which there is much more in the earth’s crust, to produce cast iron. For example, an increase in iron in ore by only 1% leads to coke savings of 2% and an increase in blast furnace productivity by 2.5%.

At the first stage, the ore is crushed into fractions, and then screened. The last step is necessary to separate iron ore by size. Next comes averaging, where the chemical composition is equalized. One of the most important and difficult stages is enrichment. The essence of the process is to remove waste rock in order to increase the iron content of the ore. Usually enrichment takes place in two stages.

The final stage is agglomeration, which is necessary to improve the flow of smelting in a blast furnace.

Production technology

The blast furnace process is a set of mechanical, physical and chemical-physical processes that occur in a functioning blast furnace. The loaded fluxes, ores and coke are converted into cast iron during the smelting process. From a chemical point of view, this is a redox process. Essentially, iron is reduced from oxides, and reducing agents are oxidized. But the process is usually called reduction, since the ultimate goal is to obtain metal.

The main unit for implementing the smelting process is the furnace (shaft). It is extremely important to ensure the counter-movement of the charge materials, as well as their interaction with the gases that are formed during smelting. To improve the combustion process, an additional supply of oxygen, natural gas and water vapor is used, which together is called blast.

More about the domain process

The coke entering directly into the furnace has a temperature of about 1,500 degrees. As a result, a mixture of gases with a temperature of 2,000 degrees is formed in the combustion zone. It rises to the top of the blast furnace and heats the materials falling towards the furnace. At the same time, the gas temperature decreases slightly, to approximately 1700-1600 degrees.

The charge is loaded into the furnace in portions. Distribution in the DP occurs in layers. Usually one portion is loaded every 5 minutes. A break is needed to free up space in the fire pit. Carburization takes place while the iron is still in the solid state, after which the temperature drops to 1,100 degrees. During this period, the reduction of iron ends and the oxidation of silicon, manganese and phosphorus begins.

As a result, we have carburized iron, which contains no more than 4% carbon. It melts and flows into the furnace. Slag also gets there, but since the specific gravity of the materials is different, they do not combine. Cast iron is released through a cast iron taphole, and slag is released through slag tapholes. In principle, this is the entire production technology described briefly.

Now let's look at another interesting question.

Main grades of cast iron

Cast iron is an alloy of iron and carbon. the last element should not be less than 2.14%. In addition, there are other elements such as silicon, phosphorus, sulfur, etc. Carbon is usually found either in a bound state (cementite) or in a free state (graphite). Cast iron can be divided into the following types:

Foundry - marked L1-L6 and LR1-LR7.
Pig iron – marked as P1 and P2. If the material is intended for castings, then these are PL1 and PL2. A metal with a high phosphorus content is designated as PF1, PF2, PF3. In addition, there is also high-quality pig iron - PVK1, PVK2 and PVK3.
Gray – SCh10, SCh15, SCh20, SCh25, SCh30 and SCh35.
Malleable cast iron - KCh30-6, ChK45-7, KCh65-3, etc. If there are numbers after the letters, then they indicate the temporary tensile strength.
Alloy cast iron, which has special properties, is designated by the letter “C”;
Antifriction (gray) – ASF.

We can say that any type of cast iron has its own further purpose. For example, conversion is used for conversion into steel and for the production of castings. At the same time, grades PL1 and PL2 will be sent to the foundry, and P1 and P2 will be used in steelmaking.

Effect of various compounds on properties

Regardless of the type and brand of cast iron, there are a number of elements that significantly affect its properties and technical characteristics. Let's take gray cast iron as an example.

The increased silicon content helps to lower the melting point and significantly improves its technological and casting properties. For this simple reason, cast iron with a high content of this element is usually sent to the foundry.

But manganese is kind of the opposite of silicon. However, it is a useful chemical element, as it increases the strength and hardness of the product.

Sulfur is one of the most harmful inclusions, which significantly reduces the fluidity and refractoriness of cast iron. Phosphorus can have both harmful and beneficial effects. In the first case, products of complex shapes are made, thin-walled and not requiring great strength. But grades of cast iron with a high phosphorus content cannot be used in mechanical engineering, where it is necessary to achieve high strength of the product.

About carburizing iron

Iron reduced in DP absorbs a wide variety of chemical elements, including carbon. As a result, full-fledged cast iron is formed. As soon as it appears in solid form, carburization begins immediately. The process itself is noticeable at relatively low temperatures of 400-500 degrees.

In addition, it is worth noting that the more carbon in iron, the lower the melting point. However, when the metal is already in a liquid state, the process proceeds somewhat more intensely. You need to understand that once the final amount of carbon is in the cast iron, it will no longer be possible to change this.

Elements such as manganese and chromium increase the carbon content, while silicon and phosphorus reduce the amount.

A little about foundry

Casting has been known to man for quite a long time, about several thousand years. This is a technological process that allows you to obtain a workpiece of the required shape. Typically, only shaped parts and blanks are made in this way. The essence of the method is that molten metal or other material (plastic) is poured into a mold, the cavity of which has the necessary configuration of the future part.

After some time, the metal hardens and a workpiece is obtained. It undergoes mechanical processing, which consists of improving the quality of the seating surfaces, obtaining the necessary roughness, etc. Interestingly, the foundry production of cast iron for industrial equipment is carried out in the ground. For this purpose, a one-time sand mold is made and the appropriate equipment is selected.

Something else interesting

It is worth drawing your attention to the fact that the foundry uses metal that was obtained in a blast furnace. In essence, during secondary melting, products with the required properties are obtained, which are changed in the melting furnace.

At the same time, castings, the chemical composition of which is left unchanged in the foundry, are produced extremely rarely. This applies in particular to cast iron. When it is necessary to produce a part made of ferrous metal, in addition to cast iron, a number of modifiers, fluxes, deoxidizers, as well as steel scrap and bayonet cast iron are loaded into the furnace.

The latter is needed to produce steel and cast iron castings. The process of cast iron production itself is not much different from blast furnace production.

Conclusion

Graphitizing annealing

/ Theory of heat treatment of metals / Second-order annealing / Annealing of cast irons / Graphitizing annealing

July 22, 2011

White, gray and high-strength (modified) cast irons are subjected to graphitizing annealing.

Annealing of white cast iron into malleable

Currently, malleable cast iron is a widely used engineering material that combines the simplicity and low cost of casting shaped parts with high mechanical properties.

Annealing schedule for white cast iron for malleability

Annealing schedule for white cast iron for malleability: I and II - the first
and second stages of graphitization.

Microstructure of malleable cast iron on a ferritic basis

X120.

First stage of graphitization

The specific volume of graphite is several times greater than that of austenite, and therefore its homogeneous nucleation in a dense metal matrix is unlikely - the elastic component ∆Fypr in the formula is too large. Dislocations, subboundaries and high-angle granites are not very effective as sites for heterogeneous graphite nucleation due to the large value of ∆Fypr.

After the formation of graphitization centers in austenite, there is a gradient of carbon concentration, since the limiting solubility of cementite in it is higher than that of graphite (in the state diagram of the Fe - C state diagram, the ES line is located to the right of the E´S´ line). For example, if the first stage of graphitization takes place at temperature t*, then the composition of austenite at the boundary with cementite is represented by point b, and at the boundary with graphite by point a.

Chart area

Section of the phase diagram of Fe - C with solid lines of stable and dashed lines of metastable

equilibrium (scheme).

The shape of graphite depends on the annealing temperature and the composition of the cast iron. Annealing carbon grows faster along high-angle boundaries and subboundaries, since iron atoms are removed more quickly along them. This undesirable branching of graphite increases with increasing temperature and after annealing at temperatures above 1050 - 1070 ° C, the mechanical properties of cast iron turn out to be very low. This determines the upper temperature limit of the first stage of graphitization.

“Theory of heat treatment of metals”,
I.I. Novikov

Annealing to remove bleach

Second stage of graphitization

The metal matrix of ductile iron is formed by the eutectoid decomposition of austenite. To obtain a purely ferritic matrix, cooling in the eutectoid decomposition temperature range must be slow (see figure Annealing schedule for white cast iron to ductile iron). Here the second stage of graphitization takes place - austenite decomposes according to the scheme A → F + G. Diagram of isothermal transformations of austenite Diagram of isothermal transformations of austenite into

Source: https://www.ktovdome.ru/teoriya_termicheskoy_obrabotki_materialov/355/82/10957.html

What type of cast iron is ductile iron made from?

Material with such graphite inclusions is characterized by high strength parameters, ductility and resistance to impact loads.

Types of cast iron

Depending on the content of these compounds, the color of the product changes. When cementite predominates, the material acquires a light sheen. This is where the name “white” came from.

Graphite has a dark color, which it imparts to castings. It is the structure of graphite inclusions that determines the plastic properties of the material.

Based on this, the alloy is divided into:

grey;
malleable;
high strength;
special purpose.

The formation of graphite of the specified form is achieved thanks to the addition of magnesium and cerium. Other forms are obtained due to different cooling rates.

Features of the production of malleable cast iron

Shape of graphite inclusions and metal base.

Austenite is iron with a face-centered lattice. This modification is high temperature. In iron-carbon steels it can form at temperatures above 727 degrees, and in pure iron at 910 degrees.

After annealing at high temperature, the product is cooled to 720-760 degrees. As a result, pearlite is formed, which further decomposes into ferrite and graphite.

When producing a ferritic alloy, it is necessary to use workpieces with a lower carbon concentration. Such products have a high melting point and therefore require an increased superheating temperature.

For the production of pearlitic alloy, workpieces with a high “C” content are used. A cupola furnace is sufficient to melt such material.

In order to increase the cooling rate of thicker parts of the casting, metal coolers are used.

The influence of carbon and silicon on the structure of cast iron and the dependence of the structure on the thickness of cast iron.

The name of this material is due only to its higher plastic properties. In fact, it cannot be forged. This type of alloy is used in the same way as its other types.

Types of malleable cast iron

This material is widely used in the manufacture of parts for machines and agricultural equipment, where resistance to constant loads and stresses is required.

This alloy has lower plastic properties. In this regard, it is used in tasks that do not require resistance to severe plastic and chemical loads.

Properties of malleable cast irons

Malleable cast iron has mechanical properties that depend on the silicon-carbon content in the graphite allotropic modification. For white-core material, chromium and manganese also have an effect.

The difference in the structure of products also determines the difference in properties. Thus, the black-core alloy is characterized by greater ductility, but lower hardness than the pearlite type.

The high strength characteristics of these alloys are provided by flake-shaped graphite. Despite their name, these products cannot be forged. They are made by casting parts into specified shapes.

The main advantage of a malleable alloy is the uniformity of properties across the cross-section of the material, as well as the absence of stress.

In terms of other characteristics they differ:

good fluidity during casting;
absorption of vibrations;
high wear resistance;
good corrosion resistance to moisture and many aggressive chemical compounds;
high resistance to shock loads.

Product marking

According to accepted standards, malleable cast irons have eleven types of marking. 4 grades correspond to ferritic, and 7 grades correspond to pearlitic.

Areas of use of the material

Mechanical properties and chemical composition of cast iron.

The use of malleable cast iron was found in mechanical engineering, automotive industry, in the production of railway cars, and in the manufacture of agricultural equipment.

The best properties for the noted applications are the pearlite type. However, despite the higher characteristics, black-heart alloy is more often used. This is due to lower production costs.

Only for the manufacture of parts subject to high loads, white-core material is used. Such products include springs, engine parts, etc.

Bottom line

Malleable cast irons have found wide application in various areas of human activity due to their high strength properties and good corrosion resistance.

They are used for the manufacture of various parts that must withstand significant constant and periodic loads.

Depending on the tasks, either ferritic or pearlitic type of material can be used. Each of them has its own advantages and disadvantages, described in this article.

Source: https://varimtutru.com/iz-kakogo-chuguna-poluchayut-kovkiy-chugun/

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

McGregor tried to throw the same high kick at Khabib.

But while everyone is figuring out Conor’s next opponents, Nate Diaz and social networks are raging that the fight against Cowboy has been bought.

But if you carefully reconsider these 40 seconds, there will be less and less reason to agree with Diaz. There is nothing surprising at all in the logic of the battle.

Therefore, from the first second the Irishman was discouraging by shortening the distance (it’s hard to expect this from him - he always works at a distance, but here he went into the clinch).

He landed three blows with his shoulders and broke his opponent’s nose.

He broke the distance, blocked the shot and pressed him towards the cage.

At the 20th second he threw a left high kick.

The knee is absolutely relevant when an opponent is knocked down at the cage. After which Conor comes in from the left - from there it is more difficult to hit him, from there it is more convenient for him to work with his left hand.

Finishing on the ground. Again - accentuated left strikes.

Conor's victory is due to good timing, home preparations and work based on his strengths and his opponent's weaknesses. But, of course, it is much easier to believe in a conspiracy theory.

After all, every victory for Conor is a negotiated deal.

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

“This is a fake fight. We're turning into wrestling. I’m very sorry,” Wanderlei Silva said. He promised to provide evidence, but then apologized.

Everything is true, but:

• Going for submission is an attempt to finish the fight as soon as possible, knowing that you may not have enough functionality in the future, because you have been preparing for two weeks.

• Lack of a large number of strikes on the ground – for the same reason. Wasting energy and dying prematurely?

• Incredible, but true: blows to the liver actually cause people to fall.

“This fight cannot be fixed. My dad taught me to live honestly. “I will never sell myself,” replied Aldo.

Then Conor finally had a real fight - when he lost to Nate Diaz. If McGregor is defeated, then everything was fair, otherwise, no. True, it is strange that a fighter with a legendary legacy (Aldo) can be bribed, but one who does not care about the record (Diaz) cannot.

Indeed, Eddie seemed passive. 12 accurate hits in 8 minutes of battle should supposedly convince of this, but statistics will argue:

• Of Conor's 90 strikes, 12 were delivered on the ground during finishing moves. That is, at a distance of 78-46 in his favor - and this is not much.

Source: `https://www.sports.ru/tribuna/blogs/mmardoboi/2701530.html`

Properties and applications of malleable cast iron

Main characteristics of the metal

High fluidity and strength.
Resistance to corrosive processes.
The metal can withstand prolonged exposure to acids and alkalis.

However, the performance of this material quickly deteriorates when exposed to low temperatures. It becomes brittle and is destroyed by impacts.

Varieties

Pearlitic - this material contains flake-shaped graphite particles.
Ferritic - This material includes ferrite and flake-shaped carbon particles.
Ferritic-pearlitic. A mixture of the two previous types of malleable cast iron.

Depending on the annealing temperature and alloying additives, the characteristics of the finished material change.

Properties

High strength and ductility.
Good viscosity.
The material has high wear resistance.

Ductile iron is the best type of base alloy. Massive structures are made from it, the individual parts of which are connected using welding equipment.

Marking

According to GOST 1215–79, there are 11 varieties of malleable cast iron, which have their own markings. They can be found in reference books on casting metals and alloys or tables on the Internet.

Production Features

To make malleable cast iron, electric furnaces are used. Special equipment allows you to regulate the simmering temperature. The most efficient ovens are those in which the air mixture can be controlled. The most popular furnaces for the production of malleable materials are muffle furnaces. They allow you to protect containers with workpieces from contact with fuel combustion products.

Areas of use

Due to its characteristics, malleable cast iron is widely used in various industries:

Production of products and parts that will be subject to severe loads during operation.
Mechanical engineering.
Agricultural industry.
Manufacturing of parts for industrial equipment and machine tools.

Source: https://metalloy.ru/splavy/kovkij-chugun

Malleable iron

Kashtanovy lane 8/14 51100 Magdalinovka village

Nikolaenko Dmitrij

Malleable cast iron Malleable cast iron ( 1 vote, average: 5 out of 5)

Ductile iron grades

In some cases, with large volumes of ordered products, some deviations from the established standards are possible if this is required to satisfy the necessary consumer request.

For the convenience of users, some data on individual alloy grades is collected in the following table.

Ductile iron application

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Source: https://metallsmaster.ru/kovkij-chugun/

Heat treatment of white cast iron (production of malleable cast iron)

White cast iron, due to its high hardness and brittleness, is not widely used. White cast iron products are the starting product for producing malleable cast iron using heat treatment.

For this purpose, white cast iron is used, which contains 2.5-3.2% C, 0.6-0.9% Si, 0.3-0.4% Mn, 0.1-0.2% P and 0 .06—0.1% S.

The initial structure of white cast iron is pearlite and ledeburite.

The ledeburite structure is found in all white cast irons, i.e. in iron-carbon alloys with a carbon content of more than 2%, which is present in the alloy in the form of cementite.

Ledeburite at room temperature is a mechanical mixture of pearlite and cementite.

We remind you that perlite is also a mechanical mixture, but of ferrite and cementite, and perlite is a finer mixture than ledeburite.

The parts are placed on special pallets , which are placed on a roller bed.

Annealing of malleable cast iron is carried out according to the regime shown in Fig. 76.

The first stage of annealing aims to decompose cementite, which is part of ledeburite; In perlite, cementite is preserved.
The second stage of annealing aims to decompose cementite, which is part of pearlite.

As a result of passing only one stage of annealing, malleable cast iron with the structure of pearlite + ferrite + carbon annealing is obtained.

Such cast iron is called pearlitic (pearlitic-ferritic, Fig. 77, a).

It has good strength properties, but low ductility. Cast iron with this structure is used in parts subject to bending and friction.

To increase strength, cast iron can be quenched and highly tempered, which improves its mechanical properties.

After a complete annealing cycle, the structure of cast iron consists of ferrite and annealed carbon, i.e. ferritic malleable cast iron is formed (Fig. 77, b).

Malleable cast iron is used to make small parts of complex shapes that are difficult to machine by cutting.

Such parts are well cast from white cast iron, and subsequent heat treatment provides them with good plastic and strength properties.

Another method of producing malleable cast iron is also used.

With this method, white cast iron parts are loaded into boxes, sprinkled with scale or ore and heated in conventional chamber furnaces.

All these measures reduce the duration of annealing for malleable cast iron.

Source: http://www.Conatem.ru/tehnologiya_metallov/termicheskaya-obrabotka-belogo-chuguna-poluchenie-kovkogo-chuguna.html

Malleable iron | Agency Lite++

Heat treatment

Regardless of the chosen option, graphitizing annealing is carried out in two stages:

Rice. 1: Scheme of graphitizing annealing of malleable cast iron

the stage includes: heating to a temperature of 930-1050°C at a rate of 200-300°C/h; holding for ~10 hours. At this stage, decomposition of primary and ledeburite cementite occurs, resulting in the formation of an austenite matrix with inclusions of flake (compact) graphite (see Fig. 1). This is followed by a decrease in temperature to ~760°C (at a rate of 50-65°C/h), i.e. to a temperature slightly above the onset of the eutectoid transformation.
the stage involves slow cooling at a rate of no higher than 5°C/h throughout the entire eutectoid transformation range, up to ~700°C. At this stage, the cementite included in the perlite decomposes. The final microstructure of cast iron depends on the parameters of the second stage: short-term exposure (~5 hours) entails the formation of a pearlite structure of the metal matrix with inclusions of compact graphite, around which a ferrite rim is located; long exposure for 20-40 hours leads to the formation of a ferritic metal matrix with inclusions of compact graphite, which is clearly shown in Fig. 1.

Advantages of malleable cast iron:

Combination of high mechanical properties with high cutting machinability (compact graphite contributes to chip brittleness and is a lubricant)
Homogeneous structure over the entire cross-section of the casting
No internal stresses in castings
Ability to withstand high alternating loads
High corrosion resistance

Standards

Technical characteristics of malleable cast iron for the manufacture of castings in Ukraine are regulated by GOST 1215-79 “Ductile iron castings. General technical conditions".

Marking

Classification of malleable cast iron

Depending on the microstructure of the metal matrix, ductile cast iron is divided into ferritic (F) and pearlitic (P):

Malleable cast iron of the ferritic class with a ferritic or ferrite-pearlite microstructure of the metal matrix is produced in the following grades: KCh 30-6, KCh 33-8, KCh 35-10, KCh 37-12
Malleable cast iron of the pearlitic class with a pearlitic microstructure of the metal matrix is produced in the following grades: KCh 45-7, KCh 50-5, KCh 55-4, KCh 60-3, KCh 65-3, KCh 70-2, KCh 80-1.5

Mechanical properties

The mechanical properties of the material of castings made of malleable cast iron of ferritic and pearlitic classes must meet the requirements of GOST 1215-79 given in table. 1.

Table 1: Mechanical properties of ductile cast iron according to GOST 1215-79

Brand	Tensile strength, MPa, (kgf/mm2)	Relative extension, %	Brinell hardness, HB
no less
CC 30-6	294 (30)	6	100-163
CC 33-8	323 (33)	8	100-163
CC 35-10	333 (35)	10	100-163
CC 37-12	362 (37)	12	110-163
CC 45-7	441 (45)	7*	150-207
CC 50-5	490 (50)	5*	170-230
CC 55-4	539 (55)	4*	192-241
CC 60-3	588 (60)	3	200-269
CC 65-3	637 (65)	3	212-269
CC 70-2	686 (70)	2	241-285
CC 80-1.5	784 (80)	1,5	270-320

Note: * By agreement between the manufacturer and the consumer, a reduction of 1% is allowed.

Chemical composition

The recommended chemical composition of malleable cast iron according to GOST 1215-79 is given in table. 2.

Table 2: Chemical composition of malleable cast iron according to GOST 1215-79

Brand	Mass fraction, %
Main components	Impurities, no more
C	Si	C+Si	Mn	P	S	Cr
Ferritic grade
CC 30-6	2,6-2,9	1,0-1,6	3,7-4,2	0,4-0,6	0,18	0,20	0,08
CC 33-8	2,6-2,9	1,0-1,6	3,7-4,2	0,4-0,6	0,18	0,20	0,08
CC 35-10	2,5-2,8	1,1-1,3	3,6-4,0	0,3-0,6	0,12	0,20	0,06
CC 37-12	2,4-2,7	1,2-1,4	3,6-4,0	0,2-0,4	0,12	0,06	0,06
Pearlite class
CC 45-7	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 50-5	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 55-4	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 60-3	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 65-3	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08
CC 70-2	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08
CC 80-1.5	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08

Ductile Iron Casting Manufacturers

Literature

Mechanical and technological properties of metals. Directory. Bobylev A.V. M., “Metallurgy”, 1980. 296 p.
Vozdvizhensky V.M. and others. Foundry alloys and technology of their smelting in mechanical engineering. - M.: Mashinostroenie, 1984. - 432 pp., illus.
Mogilev V.K., Lev O.I. Foundryman's Handbook. M. Mechanical Engineering, 1988. - 272 pp.: ill.
Encyclopedia of Inorganic Materials. In two volumes. K.: Higher School, 1977.
GOST 1215-79 “Ductile iron castings. General technical conditions".
Kolachev B.F., Livanov V.A., Elagin V.I. Metallurgy and heat treatment of non-ferrous metals and alloys Ed. 2nd, rev. and additional M.: Metallurgy, 1981. 416 p.
Handbook of iron casting./Ed. Dr. Tech. Sciences N.G. Girshovich.- L.: Mechanical Engineering. Leningr. department, 1978.- 758 pp., illus.

Source: https://on-v.com.ua/novosti/texnologii-i-nauka/kovkij-chugun/

Iron production. Cast iron grades. Production technology :

Currently, the main method of producing cast iron is smelting iron ores in blast furnaces. Smelting requires a number of raw materials, such as fluxes, iron or manganese ores, and fuel.

The fuel used is coke, which is essentially coal. The role of coke is to provide the process with reducing energy and a certain amount of heat. Let's look at cast iron production in more detail.

Since this is a complex and lengthy process, its description will take a lot of time.

Fuel for smelting

In addition, it is necessary to maintain a certain percentage of humidity, which is necessary to maintain thermal conditions.

Ores for smelting

In addition, iron ore can be divided into several groups depending on the mineral:

red iron ore – 70% iron, 30% oxygen;
magnetic iron ore – 72.4% iron, 27.6% oxygen;
brown iron ore – up to 60% iron;
spar iron ore – up to 48.3% iron.

Preparing ore for smelting

The final stage is agglomeration, which is necessary to improve the flow of smelting in a blast furnace.

Production technology

More about the domain process

Now let's look at another interesting question.

Main grades of cast iron

Foundry - marked L1-L6 and LR1-LR7.
Pig iron – marked as P1 and P2. If the material is intended for castings, then these are PL1 and PL2. A metal with a high phosphorus content is designated as PF1, PF2, PF3. In addition, there is also high-quality pig iron - PVK1, PVK2 and PVK3.
Gray – SCh10, SCh15, SCh20, SCh25, SCh30 and SCh35.
Malleable cast iron - KCh30-6, ChK45-7, KCh65-3, etc. If there are numbers after the letters, then they indicate the temporary tensile strength.
Alloy cast iron, which has special properties, is designated by the letter “C”;
Antifriction (gray) – ASF.

Effect of various compounds on properties

Regardless of the type and brand of cast iron, there are a number of elements that significantly affect its properties and technical characteristics. Let's take gray cast iron as an example.

But manganese is kind of the opposite of silicon. However, it is a useful chemical element, as it increases the strength and hardness of the product.

About carburizing iron

Elements such as manganese and chromium increase the carbon content, while silicon and phosphorus reduce the amount.

A little about foundry

Something else interesting

The latter is needed to produce steel and cast iron castings. The process of cast iron production itself is not much different from blast furnace production.

Graphitizing annealing

/ Theory of heat treatment of metals / Second-order annealing / Annealing of cast irons / Graphitizing annealing

July 22, 2011

White, gray and high-strength (modified) cast irons are subjected to graphitizing annealing.

Annealing of white cast iron into malleable

Currently, malleable cast iron is a widely used engineering material that combines the simplicity and low cost of casting shaped parts with high mechanical properties.

Annealing schedule for white cast iron for malleability

Annealing schedule for white cast iron for malleability: I and II - the first
and second stages of graphitization.

Microstructure of malleable cast iron on a ferritic basis

X120.

First stage of graphitization

The specific volume of graphite is several times greater than that of austenite, and therefore its homogeneous nucleation in a dense metal matrix is unlikely - the elastic component ∆Fypr in the formula is too large. Dislocations, subboundaries and high-angle granites are not very effective as sites for heterogeneous graphite nucleation due to the large value of ∆Fypr.

After the formation of graphitization centers in austenite, there is a gradient of carbon concentration, since the limiting solubility of cementite in it is higher than that of graphite (in the state diagram of the Fe - C state diagram, the ES line is located to the right of the E´S´ line). For example, if the first stage of graphitization takes place at temperature t*, then the composition of austenite at the boundary with cementite is represented by point b, and at the boundary with graphite by point a.

Chart area

Section of the phase diagram of Fe - C with solid lines of stable and dashed lines of metastable

equilibrium (scheme).

The shape of graphite depends on the annealing temperature and the composition of the cast iron. Annealing carbon grows faster along high-angle boundaries and subboundaries, since iron atoms are removed more quickly along them. This undesirable branching of graphite increases with increasing temperature and after annealing at temperatures above 1050 - 1070 ° C, the mechanical properties of cast iron turn out to be very low. This determines the upper temperature limit of the first stage of graphitization.

“Theory of heat treatment of metals”,
I.I. Novikov

Annealing to remove bleach

Second stage of graphitization

The metal matrix of ductile iron is formed by the eutectoid decomposition of austenite. To obtain a purely ferritic matrix, cooling in the eutectoid decomposition temperature range must be slow (see figure Annealing schedule for white cast iron to ductile iron). Here the second stage of graphitization takes place - austenite decomposes according to the scheme A → F + G. Diagram of isothermal transformations of austenite Diagram of isothermal transformations of austenite into

Source: https://www.ktovdome.ru/teoriya_termicheskoy_obrabotki_materialov/355/82/10957.html

What type of cast iron is ductile iron made from?

Material with such graphite inclusions is characterized by high strength parameters, ductility and resistance to impact loads.

Types of cast iron

Depending on the content of these compounds, the color of the product changes. When cementite predominates, the material acquires a light sheen. This is where the name “white” came from.

Graphite has a dark color, which it imparts to castings. It is the structure of graphite inclusions that determines the plastic properties of the material.

Based on this, the alloy is divided into:

grey;
malleable;
high strength;
special purpose.

The formation of graphite of the specified form is achieved thanks to the addition of magnesium and cerium. Other forms are obtained due to different cooling rates.

Features of the production of malleable cast iron

Shape of graphite inclusions and metal base.

Austenite is iron with a face-centered lattice. This modification is high temperature. In iron-carbon steels it can form at temperatures above 727 degrees, and in pure iron at 910 degrees.

After annealing at high temperature, the product is cooled to 720-760 degrees. As a result, pearlite is formed, which further decomposes into ferrite and graphite.

When producing a ferritic alloy, it is necessary to use workpieces with a lower carbon concentration. Such products have a high melting point and therefore require an increased superheating temperature.

For the production of pearlitic alloy, workpieces with a high “C” content are used. A cupola furnace is sufficient to melt such material.

In order to increase the cooling rate of thicker parts of the casting, metal coolers are used.

The influence of carbon and silicon on the structure of cast iron and the dependence of the structure on the thickness of cast iron.

The name of this material is due only to its higher plastic properties. In fact, it cannot be forged. This type of alloy is used in the same way as its other types.

Types of malleable cast iron

This material is widely used in the manufacture of parts for machines and agricultural equipment, where resistance to constant loads and stresses is required.

This alloy has lower plastic properties. In this regard, it is used in tasks that do not require resistance to severe plastic and chemical loads.

Properties of malleable cast irons

Malleable cast iron has mechanical properties that depend on the silicon-carbon content in the graphite allotropic modification. For white-core material, chromium and manganese also have an effect.

The difference in the structure of products also determines the difference in properties. Thus, the black-core alloy is characterized by greater ductility, but lower hardness than the pearlite type.

The high strength characteristics of these alloys are provided by flake-shaped graphite. Despite their name, these products cannot be forged. They are made by casting parts into specified shapes.

The main advantage of a malleable alloy is the uniformity of properties across the cross-section of the material, as well as the absence of stress.

In terms of other characteristics they differ:

good fluidity during casting;
absorption of vibrations;
high wear resistance;
good corrosion resistance to moisture and many aggressive chemical compounds;
high resistance to shock loads.

Product marking

According to accepted standards, malleable cast irons have eleven types of marking. 4 grades correspond to ferritic, and 7 grades correspond to pearlitic.

Areas of use of the material

Mechanical properties and chemical composition of cast iron.

The use of malleable cast iron was found in mechanical engineering, automotive industry, in the production of railway cars, and in the manufacture of agricultural equipment.

The best properties for the noted applications are the pearlite type. However, despite the higher characteristics, black-heart alloy is more often used. This is due to lower production costs.

Only for the manufacture of parts subject to high loads, white-core material is used. Such products include springs, engine parts, etc.

Bottom line

Malleable cast irons have found wide application in various areas of human activity due to their high strength properties and good corrosion resistance.

They are used for the manufacture of various parts that must withstand significant constant and periodic loads.

Depending on the tasks, either ferritic or pearlitic type of material can be used. Each of them has its own advantages and disadvantages, described in this article.

Source: https://varimtutru.com/iz-kakogo-chuguna-poluchayut-kovkiy-chugun/

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

McGregor tried to throw the same high kick at Khabib.

But while everyone is figuring out Conor’s next opponents, Nate Diaz and social networks are raging that the fight against Cowboy has been bought.

But if you carefully reconsider these 40 seconds, there will be less and less reason to agree with Diaz. There is nothing surprising at all in the logic of the battle.

Therefore, from the first second the Irishman was discouraging by shortening the distance (it’s hard to expect this from him - he always works at a distance, but here he went into the clinch).

He landed three blows with his shoulders and broke his opponent’s nose.

He broke the distance, blocked the shot and pressed him towards the cage.

At the 20th second he threw a left high kick.

The knee is absolutely relevant when an opponent is knocked down at the cage. After which Conor comes in from the left - from there it is more difficult to hit him, from there it is more convenient for him to work with his left hand.

Finishing on the ground. Again - accentuated left strikes.

Conor's victory is due to good timing, home preparations and work based on his strengths and his opponent's weaknesses. But, of course, it is much easier to believe in a conspiracy theory.

After all, every victory for Conor is a negotiated deal.

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

“This is a fake fight. We're turning into wrestling. I’m very sorry,” Wanderlei Silva said. He promised to provide evidence, but then apologized.

Everything is true, but:

• Going for submission is an attempt to finish the fight as soon as possible, knowing that you may not have enough functionality in the future, because you have been preparing for two weeks.

• Lack of a large number of strikes on the ground – for the same reason. Wasting energy and dying prematurely?

• Incredible, but true: blows to the liver actually cause people to fall.

“This fight cannot be fixed. My dad taught me to live honestly. “I will never sell myself,” replied Aldo.

Then Conor finally had a real fight - when he lost to Nate Diaz. If McGregor is defeated, then everything was fair, otherwise, no. True, it is strange that a fighter with a legendary legacy (Aldo) can be bribed, but one who does not care about the record (Diaz) cannot.

Indeed, Eddie seemed passive. 12 accurate hits in 8 minutes of battle should supposedly convince of this, but statistics will argue:

• Of Conor's 90 strikes, 12 were delivered on the ground during finishing moves. That is, at a distance of 78-46 in his favor - and this is not much.

Source: `https://www.sports.ru/tribuna/blogs/mmardoboi/2701530.html`

Properties and applications of malleable cast iron

Main characteristics of the metal

High fluidity and strength.
Resistance to corrosive processes.
The metal can withstand prolonged exposure to acids and alkalis.

However, the performance of this material quickly deteriorates when exposed to low temperatures. It becomes brittle and is destroyed by impacts.

Varieties

Pearlitic - this material contains flake-shaped graphite particles.
Ferritic - This material includes ferrite and flake-shaped carbon particles.
Ferritic-pearlitic. A mixture of the two previous types of malleable cast iron.

Depending on the annealing temperature and alloying additives, the characteristics of the finished material change.

Properties

High strength and ductility.
Good viscosity.
The material has high wear resistance.

Ductile iron is the best type of base alloy. Massive structures are made from it, the individual parts of which are connected using welding equipment.

Marking

According to GOST 1215–79, there are 11 varieties of malleable cast iron, which have their own markings. They can be found in reference books on casting metals and alloys or tables on the Internet.

Production Features

To make malleable cast iron, electric furnaces are used. Special equipment allows you to regulate the simmering temperature. The most efficient ovens are those in which the air mixture can be controlled. The most popular furnaces for the production of malleable materials are muffle furnaces. They allow you to protect containers with workpieces from contact with fuel combustion products.

Areas of use

Due to its characteristics, malleable cast iron is widely used in various industries:

Production of products and parts that will be subject to severe loads during operation.
Mechanical engineering.
Agricultural industry.
Manufacturing of parts for industrial equipment and machine tools.

Source: https://metalloy.ru/splavy/kovkij-chugun

Malleable iron

Kashtanovy lane 8/14 51100 Magdalinovka village

Nikolaenko Dmitrij

Malleable cast iron Malleable cast iron ( 1 vote, average: 5 out of 5)

Ductile iron grades

In some cases, with large volumes of ordered products, some deviations from the established standards are possible if this is required to satisfy the necessary consumer request.

For the convenience of users, some data on individual alloy grades is collected in the following table.

Ductile iron application

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Source: https://metallsmaster.ru/kovkij-chugun/

Heat treatment of white cast iron (production of malleable cast iron)

White cast iron, due to its high hardness and brittleness, is not widely used. White cast iron products are the starting product for producing malleable cast iron using heat treatment.

For this purpose, white cast iron is used, which contains 2.5-3.2% C, 0.6-0.9% Si, 0.3-0.4% Mn, 0.1-0.2% P and 0 .06—0.1% S.

The initial structure of white cast iron is pearlite and ledeburite.

The ledeburite structure is found in all white cast irons, i.e. in iron-carbon alloys with a carbon content of more than 2%, which is present in the alloy in the form of cementite.

Ledeburite at room temperature is a mechanical mixture of pearlite and cementite.

We remind you that perlite is also a mechanical mixture, but of ferrite and cementite, and perlite is a finer mixture than ledeburite.

The parts are placed on special pallets , which are placed on a roller bed.

Annealing of malleable cast iron is carried out according to the regime shown in Fig. 76.

The first stage of annealing aims to decompose cementite, which is part of ledeburite; In perlite, cementite is preserved.
The second stage of annealing aims to decompose cementite, which is part of pearlite.

As a result of passing only one stage of annealing, malleable cast iron with the structure of pearlite + ferrite + carbon annealing is obtained.

Such cast iron is called pearlitic (pearlitic-ferritic, Fig. 77, a).

It has good strength properties, but low ductility. Cast iron with this structure is used in parts subject to bending and friction.

To increase strength, cast iron can be quenched and highly tempered, which improves its mechanical properties.

After a complete annealing cycle, the structure of cast iron consists of ferrite and annealed carbon, i.e. ferritic malleable cast iron is formed (Fig. 77, b).

Malleable cast iron is used to make small parts of complex shapes that are difficult to machine by cutting.

Such parts are well cast from white cast iron, and subsequent heat treatment provides them with good plastic and strength properties.

Another method of producing malleable cast iron is also used.

With this method, white cast iron parts are loaded into boxes, sprinkled with scale or ore and heated in conventional chamber furnaces.

All these measures reduce the duration of annealing for malleable cast iron.

Source: http://www.Conatem.ru/tehnologiya_metallov/termicheskaya-obrabotka-belogo-chuguna-poluchenie-kovkogo-chuguna.html

Malleable iron | Agency Lite++

Heat treatment

Regardless of the chosen option, graphitizing annealing is carried out in two stages:

Rice. 1: Scheme of graphitizing annealing of malleable cast iron

the stage includes: heating to a temperature of 930-1050°C at a rate of 200-300°C/h; holding for ~10 hours. At this stage, decomposition of primary and ledeburite cementite occurs, resulting in the formation of an austenite matrix with inclusions of flake (compact) graphite (see Fig. 1). This is followed by a decrease in temperature to ~760°C (at a rate of 50-65°C/h), i.e. to a temperature slightly above the onset of the eutectoid transformation.
the stage involves slow cooling at a rate of no higher than 5°C/h throughout the entire eutectoid transformation range, up to ~700°C. At this stage, the cementite included in the perlite decomposes. The final microstructure of cast iron depends on the parameters of the second stage: short-term exposure (~5 hours) entails the formation of a pearlite structure of the metal matrix with inclusions of compact graphite, around which a ferrite rim is located; long exposure for 20-40 hours leads to the formation of a ferritic metal matrix with inclusions of compact graphite, which is clearly shown in Fig. 1.

Advantages of malleable cast iron:

Combination of high mechanical properties with high cutting machinability (compact graphite contributes to chip brittleness and is a lubricant)
Homogeneous structure over the entire cross-section of the casting
No internal stresses in castings
Ability to withstand high alternating loads
High corrosion resistance

Standards

Technical characteristics of malleable cast iron for the manufacture of castings in Ukraine are regulated by GOST 1215-79 “Ductile iron castings. General technical conditions".

Marking

Classification of malleable cast iron

Depending on the microstructure of the metal matrix, ductile cast iron is divided into ferritic (F) and pearlitic (P):

Malleable cast iron of the ferritic class with a ferritic or ferrite-pearlite microstructure of the metal matrix is produced in the following grades: KCh 30-6, KCh 33-8, KCh 35-10, KCh 37-12
Malleable cast iron of the pearlitic class with a pearlitic microstructure of the metal matrix is produced in the following grades: KCh 45-7, KCh 50-5, KCh 55-4, KCh 60-3, KCh 65-3, KCh 70-2, KCh 80-1.5

Mechanical properties

The mechanical properties of the material of castings made of malleable cast iron of ferritic and pearlitic classes must meet the requirements of GOST 1215-79 given in table. 1.

Table 1: Mechanical properties of ductile cast iron according to GOST 1215-79

Brand	Tensile strength, MPa, (kgf/mm2)	Relative extension, %	Brinell hardness, HB
no less
CC 30-6	294 (30)	6	100-163
CC 33-8	323 (33)	8	100-163
CC 35-10	333 (35)	10	100-163
CC 37-12	362 (37)	12	110-163
CC 45-7	441 (45)	7*	150-207
CC 50-5	490 (50)	5*	170-230
CC 55-4	539 (55)	4*	192-241
CC 60-3	588 (60)	3	200-269
CC 65-3	637 (65)	3	212-269
CC 70-2	686 (70)	2	241-285
CC 80-1.5	784 (80)	1,5	270-320

Note: * By agreement between the manufacturer and the consumer, a reduction of 1% is allowed.

Chemical composition

The recommended chemical composition of malleable cast iron according to GOST 1215-79 is given in table. 2.

Table 2: Chemical composition of malleable cast iron according to GOST 1215-79

Brand	Mass fraction, %
Main components	Impurities, no more
C	Si	C+Si	Mn	P	S	Cr
Ferritic grade
CC 30-6	2,6-2,9	1,0-1,6	3,7-4,2	0,4-0,6	0,18	0,20	0,08
CC 33-8	2,6-2,9	1,0-1,6	3,7-4,2	0,4-0,6	0,18	0,20	0,08
CC 35-10	2,5-2,8	1,1-1,3	3,6-4,0	0,3-0,6	0,12	0,20	0,06
CC 37-12	2,4-2,7	1,2-1,4	3,6-4,0	0,2-0,4	0,12	0,06	0,06
Pearlite class
CC 45-7	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 50-5	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 55-4	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 60-3	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 65-3	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08
CC 70-2	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08
CC 80-1.5	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08

Ductile Iron Casting Manufacturers

Literature

Mechanical and technological properties of metals. Directory. Bobylev A.V. M., “Metallurgy”, 1980. 296 p.
Vozdvizhensky V.M. and others. Foundry alloys and technology of their smelting in mechanical engineering. - M.: Mashinostroenie, 1984. - 432 pp., illus.
Mogilev V.K., Lev O.I. Foundryman's Handbook. M. Mechanical Engineering, 1988. - 272 pp.: ill.
Encyclopedia of Inorganic Materials. In two volumes. K.: Higher School, 1977.
GOST 1215-79 “Ductile iron castings. General technical conditions".
Kolachev B.F., Livanov V.A., Elagin V.I. Metallurgy and heat treatment of non-ferrous metals and alloys Ed. 2nd, rev. and additional M.: Metallurgy, 1981. 416 p.
Handbook of iron casting./Ed. Dr. Tech. Sciences N.G. Girshovich.- L.: Mechanical Engineering. Leningr. department, 1978.- 758 pp., illus.

Source: https://on-v.com.ua/novosti/texnologii-i-nauka/kovkij-chugun/

Iron production. Cast iron grades. Production technology :

Currently, the main method of producing cast iron is smelting iron ores in blast furnaces. Smelting requires a number of raw materials, such as fluxes, iron or manganese ores, and fuel.

The fuel used is coke, which is essentially coal. The role of coke is to provide the process with reducing energy and a certain amount of heat. Let's look at cast iron production in more detail.

Since this is a complex and lengthy process, its description will take a lot of time.

Fuel for smelting

In addition, it is necessary to maintain a certain percentage of humidity, which is necessary to maintain thermal conditions.

Ores for smelting

In addition, iron ore can be divided into several groups depending on the mineral:

red iron ore – 70% iron, 30% oxygen;
magnetic iron ore – 72.4% iron, 27.6% oxygen;
brown iron ore – up to 60% iron;
spar iron ore – up to 48.3% iron.

Preparing ore for smelting

The final stage is agglomeration, which is necessary to improve the flow of smelting in a blast furnace.

Production technology

More about the domain process

Now let's look at another interesting question.

Main grades of cast iron

Foundry - marked L1-L6 and LR1-LR7.
Pig iron – marked as P1 and P2. If the material is intended for castings, then these are PL1 and PL2. A metal with a high phosphorus content is designated as PF1, PF2, PF3. In addition, there is also high-quality pig iron - PVK1, PVK2 and PVK3.
Gray – SCh10, SCh15, SCh20, SCh25, SCh30 and SCh35.
Malleable cast iron - KCh30-6, ChK45-7, KCh65-3, etc. If there are numbers after the letters, then they indicate the temporary tensile strength.
Alloy cast iron, which has special properties, is designated by the letter “C”;
Antifriction (gray) – ASF.

Effect of various compounds on properties

Regardless of the type and brand of cast iron, there are a number of elements that significantly affect its properties and technical characteristics. Let's take gray cast iron as an example.

But manganese is kind of the opposite of silicon. However, it is a useful chemical element, as it increases the strength and hardness of the product.

About carburizing iron

Elements such as manganese and chromium increase the carbon content, while silicon and phosphorus reduce the amount.

A little about foundry

Something else interesting

The latter is needed to produce steel and cast iron castings. The process of cast iron production itself is not much different from blast furnace production.

Conclusion

Graphitizing annealing

/ Theory of heat treatment of metals / Second-order annealing / Annealing of cast irons / Graphitizing annealing

July 22, 2011

White, gray and high-strength (modified) cast irons are subjected to graphitizing annealing.

Annealing of white cast iron into malleable

Currently, malleable cast iron is a widely used engineering material that combines the simplicity and low cost of casting shaped parts with high mechanical properties.

Annealing schedule for white cast iron for malleability

Annealing schedule for white cast iron for malleability: I and II - the first
and second stages of graphitization.

Microstructure of malleable cast iron on a ferritic basis

X120.

First stage of graphitization

The specific volume of graphite is several times greater than that of austenite, and therefore its homogeneous nucleation in a dense metal matrix is unlikely - the elastic component ∆Fypr in the formula is too large. Dislocations, subboundaries and high-angle granites are not very effective as sites for heterogeneous graphite nucleation due to the large value of ∆Fypr.

After the formation of graphitization centers in austenite, there is a gradient of carbon concentration, since the limiting solubility of cementite in it is higher than that of graphite (in the state diagram of the Fe - C state diagram, the ES line is located to the right of the E´S´ line). For example, if the first stage of graphitization takes place at temperature t*, then the composition of austenite at the boundary with cementite is represented by point b, and at the boundary with graphite by point a.

Chart area

Section of the phase diagram of Fe - C with solid lines of stable and dashed lines of metastable

equilibrium (scheme).

The shape of graphite depends on the annealing temperature and the composition of the cast iron. Annealing carbon grows faster along high-angle boundaries and subboundaries, since iron atoms are removed more quickly along them. This undesirable branching of graphite increases with increasing temperature and after annealing at temperatures above 1050 - 1070 ° C, the mechanical properties of cast iron turn out to be very low. This determines the upper temperature limit of the first stage of graphitization.

“Theory of heat treatment of metals”,
I.I. Novikov

Annealing to remove bleach

Second stage of graphitization

The metal matrix of ductile iron is formed by the eutectoid decomposition of austenite. To obtain a purely ferritic matrix, cooling in the eutectoid decomposition temperature range must be slow (see figure Annealing schedule for white cast iron to ductile iron). Here the second stage of graphitization takes place - austenite decomposes according to the scheme A → F + G. Diagram of isothermal transformations of austenite Diagram of isothermal transformations of austenite into

Source: https://www.ktovdome.ru/teoriya_termicheskoy_obrabotki_materialov/355/82/10957.html

What type of cast iron is ductile iron made from?

Material with such graphite inclusions is characterized by high strength parameters, ductility and resistance to impact loads.

Types of cast iron

Depending on the content of these compounds, the color of the product changes. When cementite predominates, the material acquires a light sheen. This is where the name “white” came from.

Graphite has a dark color, which it imparts to castings. It is the structure of graphite inclusions that determines the plastic properties of the material.

Based on this, the alloy is divided into:

grey;
malleable;
high strength;
special purpose.

The formation of graphite of the specified form is achieved thanks to the addition of magnesium and cerium. Other forms are obtained due to different cooling rates.

Features of the production of malleable cast iron

Shape of graphite inclusions and metal base.

Austenite is iron with a face-centered lattice. This modification is high temperature. In iron-carbon steels it can form at temperatures above 727 degrees, and in pure iron at 910 degrees.

After annealing at high temperature, the product is cooled to 720-760 degrees. As a result, pearlite is formed, which further decomposes into ferrite and graphite.

When producing a ferritic alloy, it is necessary to use workpieces with a lower carbon concentration. Such products have a high melting point and therefore require an increased superheating temperature.

For the production of pearlitic alloy, workpieces with a high “C” content are used. A cupola furnace is sufficient to melt such material.

In order to increase the cooling rate of thicker parts of the casting, metal coolers are used.

The influence of carbon and silicon on the structure of cast iron and the dependence of the structure on the thickness of cast iron.

The name of this material is due only to its higher plastic properties. In fact, it cannot be forged. This type of alloy is used in the same way as its other types.

Types of malleable cast iron

This material is widely used in the manufacture of parts for machines and agricultural equipment, where resistance to constant loads and stresses is required.

This alloy has lower plastic properties. In this regard, it is used in tasks that do not require resistance to severe plastic and chemical loads.

Properties of malleable cast irons

Malleable cast iron has mechanical properties that depend on the silicon-carbon content in the graphite allotropic modification. For white-core material, chromium and manganese also have an effect.

The difference in the structure of products also determines the difference in properties. Thus, the black-core alloy is characterized by greater ductility, but lower hardness than the pearlite type.

The high strength characteristics of these alloys are provided by flake-shaped graphite. Despite their name, these products cannot be forged. They are made by casting parts into specified shapes.

The main advantage of a malleable alloy is the uniformity of properties across the cross-section of the material, as well as the absence of stress.

In terms of other characteristics they differ:

good fluidity during casting;
absorption of vibrations;
high wear resistance;
good corrosion resistance to moisture and many aggressive chemical compounds;
high resistance to shock loads.

Product marking

According to accepted standards, malleable cast irons have eleven types of marking. 4 grades correspond to ferritic, and 7 grades correspond to pearlitic.

Areas of use of the material

Mechanical properties and chemical composition of cast iron.

The use of malleable cast iron was found in mechanical engineering, automotive industry, in the production of railway cars, and in the manufacture of agricultural equipment.

The best properties for the noted applications are the pearlite type. However, despite the higher characteristics, black-heart alloy is more often used. This is due to lower production costs.

Only for the manufacture of parts subject to high loads, white-core material is used. Such products include springs, engine parts, etc.

Bottom line

Malleable cast irons have found wide application in various areas of human activity due to their high strength properties and good corrosion resistance.

They are used for the manufacture of various parts that must withstand significant constant and periodic loads.

Depending on the tasks, either ferritic or pearlitic type of material can be used. Each of them has its own advantages and disadvantages, described in this article.

Source: https://varimtutru.com/iz-kakogo-chuguna-poluchayut-kovkiy-chugun/

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

McGregor tried to throw the same high kick at Khabib.

But while everyone is figuring out Conor’s next opponents, Nate Diaz and social networks are raging that the fight against Cowboy has been bought.

But if you carefully reconsider these 40 seconds, there will be less and less reason to agree with Diaz. There is nothing surprising at all in the logic of the battle.

Therefore, from the first second the Irishman was discouraging by shortening the distance (it’s hard to expect this from him - he always works at a distance, but here he went into the clinch).

He landed three blows with his shoulders and broke his opponent’s nose.

He broke the distance, blocked the shot and pressed him towards the cage.

At the 20th second he threw a left high kick.

The knee is absolutely relevant when an opponent is knocked down at the cage. After which Conor comes in from the left - from there it is more difficult to hit him, from there it is more convenient for him to work with his left hand.

Finishing on the ground. Again - accentuated left strikes.

Conor's victory is due to good timing, home preparations and work based on his strengths and his opponent's weaknesses. But, of course, it is much easier to believe in a conspiracy theory.

After all, every victory for Conor is a negotiated deal.

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

“This is a fake fight. We're turning into wrestling. I’m very sorry,” Wanderlei Silva said. He promised to provide evidence, but then apologized.

Everything is true, but:

• Going for submission is an attempt to finish the fight as soon as possible, knowing that you may not have enough functionality in the future, because you have been preparing for two weeks.

• Lack of a large number of strikes on the ground – for the same reason. Wasting energy and dying prematurely?

• Incredible, but true: blows to the liver actually cause people to fall.

“This fight cannot be fixed. My dad taught me to live honestly. “I will never sell myself,” replied Aldo.

Then Conor finally had a real fight - when he lost to Nate Diaz. If McGregor is defeated, then everything was fair, otherwise, no. True, it is strange that a fighter with a legendary legacy (Aldo) can be bribed, but one who does not care about the record (Diaz) cannot.

Indeed, Eddie seemed passive. 12 accurate hits in 8 minutes of battle should supposedly convince of this, but statistics will argue:

• Of Conor's 90 strikes, 12 were delivered on the ground during finishing moves. That is, at a distance of 78-46 in his favor - and this is not much.

Source: `https://www.sports.ru/tribuna/blogs/mmardoboi/2701530.html`

Properties and applications of malleable cast iron

Main characteristics of the metal

High fluidity and strength.
Resistance to corrosive processes.
The metal can withstand prolonged exposure to acids and alkalis.

However, the performance of this material quickly deteriorates when exposed to low temperatures. It becomes brittle and is destroyed by impacts.

Varieties

Pearlitic - this material contains flake-shaped graphite particles.
Ferritic - This material includes ferrite and flake-shaped carbon particles.
Ferritic-pearlitic. A mixture of the two previous types of malleable cast iron.

Depending on the annealing temperature and alloying additives, the characteristics of the finished material change.

Properties

High strength and ductility.
Good viscosity.
The material has high wear resistance.

Ductile iron is the best type of base alloy. Massive structures are made from it, the individual parts of which are connected using welding equipment.

Marking

According to GOST 1215–79, there are 11 varieties of malleable cast iron, which have their own markings. They can be found in reference books on casting metals and alloys or tables on the Internet.

Production Features

To make malleable cast iron, electric furnaces are used. Special equipment allows you to regulate the simmering temperature. The most efficient ovens are those in which the air mixture can be controlled. The most popular furnaces for the production of malleable materials are muffle furnaces. They allow you to protect containers with workpieces from contact with fuel combustion products.

Areas of use

Due to its characteristics, malleable cast iron is widely used in various industries:

Production of products and parts that will be subject to severe loads during operation.
Mechanical engineering.
Agricultural industry.
Manufacturing of parts for industrial equipment and machine tools.

Source: https://metalloy.ru/splavy/kovkij-chugun

Malleable iron

Kashtanovy lane 8/14 51100 Magdalinovka village

Nikolaenko Dmitrij

Malleable cast iron Malleable cast iron ( 1 vote, average: 5 out of 5)

Ductile iron grades

In some cases, with large volumes of ordered products, some deviations from the established standards are possible if this is required to satisfy the necessary consumer request.

For the convenience of users, some data on individual alloy grades is collected in the following table.

Ductile iron application

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Source: https://metallsmaster.ru/kovkij-chugun/

Heat treatment of white cast iron (production of malleable cast iron)

White cast iron, due to its high hardness and brittleness, is not widely used. White cast iron products are the starting product for producing malleable cast iron using heat treatment.

For this purpose, white cast iron is used, which contains 2.5-3.2% C, 0.6-0.9% Si, 0.3-0.4% Mn, 0.1-0.2% P and 0 .06—0.1% S.

The initial structure of white cast iron is pearlite and ledeburite.

The ledeburite structure is found in all white cast irons, i.e. in iron-carbon alloys with a carbon content of more than 2%, which is present in the alloy in the form of cementite.

Ledeburite at room temperature is a mechanical mixture of pearlite and cementite.

We remind you that perlite is also a mechanical mixture, but of ferrite and cementite, and perlite is a finer mixture than ledeburite.

The parts are placed on special pallets , which are placed on a roller bed.

Annealing of malleable cast iron is carried out according to the regime shown in Fig. 76.

The first stage of annealing aims to decompose cementite, which is part of ledeburite; In perlite, cementite is preserved.
The second stage of annealing aims to decompose cementite, which is part of pearlite.

As a result of passing only one stage of annealing, malleable cast iron with the structure of pearlite + ferrite + carbon annealing is obtained.

Such cast iron is called pearlitic (pearlitic-ferritic, Fig. 77, a).

It has good strength properties, but low ductility. Cast iron with this structure is used in parts subject to bending and friction.

To increase strength, cast iron can be quenched and highly tempered, which improves its mechanical properties.

After a complete annealing cycle, the structure of cast iron consists of ferrite and annealed carbon, i.e. ferritic malleable cast iron is formed (Fig. 77, b).

Malleable cast iron is used to make small parts of complex shapes that are difficult to machine by cutting.

Such parts are well cast from white cast iron, and subsequent heat treatment provides them with good plastic and strength properties.

Another method of producing malleable cast iron is also used.

With this method, white cast iron parts are loaded into boxes, sprinkled with scale or ore and heated in conventional chamber furnaces.

All these measures reduce the duration of annealing for malleable cast iron.

Source: http://www.Conatem.ru/tehnologiya_metallov/termicheskaya-obrabotka-belogo-chuguna-poluchenie-kovkogo-chuguna.html

Malleable iron | Agency Lite++

Heat treatment

Regardless of the chosen option, graphitizing annealing is carried out in two stages:

Rice. 1: Scheme of graphitizing annealing of malleable cast iron

the stage includes: heating to a temperature of 930-1050°C at a rate of 200-300°C/h; holding for ~10 hours. At this stage, decomposition of primary and ledeburite cementite occurs, resulting in the formation of an austenite matrix with inclusions of flake (compact) graphite (see Fig. 1). This is followed by a decrease in temperature to ~760°C (at a rate of 50-65°C/h), i.e. to a temperature slightly above the onset of the eutectoid transformation.
the stage involves slow cooling at a rate of no higher than 5°C/h throughout the entire eutectoid transformation range, up to ~700°C. At this stage, the cementite included in the perlite decomposes. The final microstructure of cast iron depends on the parameters of the second stage: short-term exposure (~5 hours) entails the formation of a pearlite structure of the metal matrix with inclusions of compact graphite, around which a ferrite rim is located; long exposure for 20-40 hours leads to the formation of a ferritic metal matrix with inclusions of compact graphite, which is clearly shown in Fig. 1.

Advantages of malleable cast iron:

Combination of high mechanical properties with high cutting machinability (compact graphite contributes to chip brittleness and is a lubricant)
Homogeneous structure over the entire cross-section of the casting
No internal stresses in castings
Ability to withstand high alternating loads
High corrosion resistance

Standards

Technical characteristics of malleable cast iron for the manufacture of castings in Ukraine are regulated by GOST 1215-79 “Ductile iron castings. General technical conditions".

Marking

Classification of malleable cast iron

Depending on the microstructure of the metal matrix, ductile cast iron is divided into ferritic (F) and pearlitic (P):

Malleable cast iron of the ferritic class with a ferritic or ferrite-pearlite microstructure of the metal matrix is produced in the following grades: KCh 30-6, KCh 33-8, KCh 35-10, KCh 37-12
Malleable cast iron of the pearlitic class with a pearlitic microstructure of the metal matrix is produced in the following grades: KCh 45-7, KCh 50-5, KCh 55-4, KCh 60-3, KCh 65-3, KCh 70-2, KCh 80-1.5

Mechanical properties

The mechanical properties of the material of castings made of malleable cast iron of ferritic and pearlitic classes must meet the requirements of GOST 1215-79 given in table. 1.

Table 1: Mechanical properties of ductile cast iron according to GOST 1215-79

Brand	Tensile strength, MPa, (kgf/mm2)	Relative extension, %	Brinell hardness, HB
no less
CC 30-6	294 (30)	6	100-163
CC 33-8	323 (33)	8	100-163
CC 35-10	333 (35)	10	100-163
CC 37-12	362 (37)	12	110-163
CC 45-7	441 (45)	7*	150-207
CC 50-5	490 (50)	5*	170-230
CC 55-4	539 (55)	4*	192-241
CC 60-3	588 (60)	3	200-269
CC 65-3	637 (65)	3	212-269
CC 70-2	686 (70)	2	241-285
CC 80-1.5	784 (80)	1,5	270-320

Note: * By agreement between the manufacturer and the consumer, a reduction of 1% is allowed.

Chemical composition

The recommended chemical composition of malleable cast iron according to GOST 1215-79 is given in table. 2.

Table 2: Chemical composition of malleable cast iron according to GOST 1215-79

Brand	Mass fraction, %
Main components	Impurities, no more
C	Si	C+Si	Mn	P	S	Cr
Ferritic grade
CC 30-6	2,6-2,9	1,0-1,6	3,7-4,2	0,4-0,6	0,18	0,20	0,08
CC 33-8	2,6-2,9	1,0-1,6	3,7-4,2	0,4-0,6	0,18	0,20	0,08
CC 35-10	2,5-2,8	1,1-1,3	3,6-4,0	0,3-0,6	0,12	0,20	0,06
CC 37-12	2,4-2,7	1,2-1,4	3,6-4,0	0,2-0,4	0,12	0,06	0,06
Pearlite class
CC 45-7	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 50-5	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 55-4	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 60-3	2,5-2,8	1,1-1,3	3,6-3,9	0,3-1,0	0,10	0,20	0,08
CC 65-3	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08
CC 70-2	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08
CC 80-1.5	2,4-2,7	1,2-1,4	3,6-3,9	0,3-1,0	0,10	0,06	0,08

Ductile Iron Casting Manufacturers

Literature

Mechanical and technological properties of metals. Directory. Bobylev A.V. M., “Metallurgy”, 1980. 296 p.
Vozdvizhensky V.M. and others. Foundry alloys and technology of their smelting in mechanical engineering. - M.: Mashinostroenie, 1984. - 432 pp., illus.
Mogilev V.K., Lev O.I. Foundryman's Handbook. M. Mechanical Engineering, 1988. - 272 pp.: ill.
Encyclopedia of Inorganic Materials. In two volumes. K.: Higher School, 1977.
GOST 1215-79 “Ductile iron castings. General technical conditions".
Kolachev B.F., Livanov V.A., Elagin V.I. Metallurgy and heat treatment of non-ferrous metals and alloys Ed. 2nd, rev. and additional M.: Metallurgy, 1981. 416 p.
Handbook of iron casting./Ed. Dr. Tech. Sciences N.G. Girshovich.- L.: Mechanical Engineering. Leningr. department, 1978.- 758 pp., illus.

Source: https://on-v.com.ua/novosti/texnologii-i-nauka/kovkij-chugun/

Iron production. Cast iron grades. Production technology :

Currently, the main method of producing cast iron is smelting iron ores in blast furnaces. Smelting requires a number of raw materials, such as fluxes, iron or manganese ores, and fuel.

The fuel used is coke, which is essentially coal. The role of coke is to provide the process with reducing energy and a certain amount of heat. Let's look at cast iron production in more detail.

Since this is a complex and lengthy process, its description will take a lot of time.

Fuel for smelting

In addition, it is necessary to maintain a certain percentage of humidity, which is necessary to maintain thermal conditions.

Ores for smelting

In addition, iron ore can be divided into several groups depending on the mineral:

red iron ore – 70% iron, 30% oxygen;
magnetic iron ore – 72.4% iron, 27.6% oxygen;
brown iron ore – up to 60% iron;
spar iron ore – up to 48.3% iron.

Preparing ore for smelting

The final stage is agglomeration, which is necessary to improve the flow of smelting in a blast furnace.

Production technology

More about the domain process

Now let's look at another interesting question.

Main grades of cast iron

Foundry - marked L1-L6 and LR1-LR7.
Pig iron – marked as P1 and P2. If the material is intended for castings, then these are PL1 and PL2. A metal with a high phosphorus content is designated as PF1, PF2, PF3. In addition, there is also high-quality pig iron - PVK1, PVK2 and PVK3.
Gray – SCh10, SCh15, SCh20, SCh25, SCh30 and SCh35.
Malleable cast iron - KCh30-6, ChK45-7, KCh65-3, etc. If there are numbers after the letters, then they indicate the temporary tensile strength.
Alloy cast iron, which has special properties, is designated by the letter “C”;
Antifriction (gray) – ASF.

Effect of various compounds on properties

Regardless of the type and brand of cast iron, there are a number of elements that significantly affect its properties and technical characteristics. Let's take gray cast iron as an example.

But manganese is kind of the opposite of silicon. However, it is a useful chemical element, as it increases the strength and hardness of the product.

About carburizing iron

Elements such as manganese and chromium increase the carbon content, while silicon and phosphorus reduce the amount.

A little about foundry

Something else interesting

The latter is needed to produce steel and cast iron castings. The process of cast iron production itself is not much different from blast furnace production.

Conclusion

In addition to the ones we have discussed, there are other methods for producing cast iron. For example, smelting in open hearth furnaces. But this method is obsolete, since it is too energy-consuming, although the quality of the metal is at a good level. A completely different matter is the converter method, which, on the contrary, is only gaining popularity every year.

For example, the production of cast iron in Russia in converters takes up about 30-45% of total production. The converter method has a number of significant advantages, one of them is high melting speed. In addition, cast iron is poured from the converter directly into molds and used for its intended purpose. It is worth noting that it is impossible to stop the DP, since production is continuous.

As a last resort, conservation takes place, in which the coke smolders in a furnace. If a blast furnace stops, it is easier to build a new one than to start an old one.

Source: https://www.syl.ru/article/169157/new_proizvodstvo-chuguna-marki-chuguna-tehnologiya-proizvodstva

Graphitizing annealing

Annealing of white cast iron into malleable

First stage of graphitization

What type of cast iron is ductile iron made from?

Types of cast iron

Features of the production of malleable cast iron

Types of malleable cast iron

Properties of malleable cast irons

Product marking

Areas of use of the material

Bottom line

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

Properties and applications of malleable cast iron

Properties and applications of malleable cast iron

Properties and applications of malleable cast iron

Main characteristics of the metal

Malleable iron

Malleable iron

Malleable iron

Ductile iron grades

Heat treatment of white cast iron (production of malleable cast iron)

Heat treatment of white cast iron (production of malleable cast iron)

Heat treatment of white cast iron (production of malleable cast iron)

The initial structure of white cast iron is pearlite and ledeburite.

Malleable iron | Agency Lite++

Malleable iron | Agency Lite++

Malleable iron | Agency Lite++

Standards

Iron production. Cast iron grades. Production technology :

Iron production. Cast iron grades. Production technology :

Iron production. Cast iron grades. Production technology :

Fuel for smelting

Graphitizing annealing

Annealing of white cast iron into malleable

What type of cast iron is ductile iron made from?

Types of cast iron

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

Properties and applications of malleable cast iron

Main characteristics of the metal

Varieties

Malleable iron

Ductile iron grades

Ductile iron application

Heat treatment of white cast iron (production of malleable cast iron)

The initial structure of white cast iron is pearlite and ledeburite.

Malleable cast iron is used to make small parts of complex shapes that are difficult to machine by cutting.

Malleable iron | Agency Lite++

Standards

Marking

Iron production. Cast iron grades. Production technology :

Fuel for smelting

Ores for smelting

Graphitizing annealing

Annealing of white cast iron into malleable

First stage of graphitization

What type of cast iron is ductile iron made from?

Types of cast iron

Features of the production of malleable cast iron

Types of malleable cast iron

Properties of malleable cast irons

Product marking

Areas of use of the material

Bottom line

They say that the Conor-Cerrone fight is a deal. We analyze the knockout and explain why this is not so

Mendes, Aldo and Alvarez - McGregor was accused of buying fights in three out of four title events

Source: https://www.sports.ru/tribuna/blogs/mmardoboi/2701530.html

Properties and applications of malleable cast iron

Properties and applications of malleable cast iron

Main characteristics of the metal

Main characteristics of the metal

Varieties

Varieties

Properties

Properties

Marking

Marking

Production Features

Production Features

Source: `https://www.sports.ru/tribuna/blogs/mmardoboi/2701530.html`

Source: `https://www.sports.ru/tribuna/blogs/mmardoboi/2701530.html`