What is cast iron used for - Metals and their processing

The use of cast iron and products made from it in construction and other areas

Cast iron is the main metal of ferrous metallurgy. It is an alloy of iron and carbon. Cast iron may contain special additives that make its properties special. This cast iron has the characteristics of wear resistance, corrosion resistance, heat resistance, non-magneticity and others. We will talk about the properties, composition and areas of application of gray, white, malleable cast iron, as well as high-strength and granular cast iron below.

Due to its valuable properties, low cost and good casting characteristics, cast iron is used for the manufacture of various parts and objects. Cast iron can be used to produce products of interesting and special shapes, since this material has excellent hardness and strength. Made cast iron objects can withstand quite serious loads. It is for this reason that machine bodies and machine tool bases are made of cast iron.

Cast iron has always been used for the manufacture of parts and heavy industrial . It was used in metallurgy and machine tool building. Moreover, this material was taken in very large quantities. It was used as the main one for small items and for large items, the weight of which reached hundreds of tons.
in mechanical engineering . This is the type that is always taken for the manufacture of critical parts. Cast iron machine products resist vibration and vibration well.
In the automotive industry, cylinder blocks are made from cast iron. These are critical parts that must have high strength and wear resistance. Cast iron helps to meet these qualities. To make these indicators optimal, special additives in the form of graphite are added to cast iron. Graphite increases the strength properties of the alloy several times. Additives make it possible to perfect cast iron and use it in the manufacture of diesel crankshafts.
Brake pads are made from cast iron . We know that these parts operate under high friction. Cast iron helps them withstand these harsh conditions. In addition, rollers for flour-grinding and paper-making machines are made from cast iron.
Cast iron products work well at low temperatures . For this purpose, malleable cast iron is used. It is used to make parts of tractors and complex mechanisms that will subsequently operate under harsh conditions.
Cast iron is widely used to make household items . This material is very popular among our population. Cast iron pots, frying pans, cauldrons can be found both in an ordinary kitchen and in a restaurant's arsenal of dishes. This is truly unique tableware.
Any housewife knows about a cast iron frying pan, which has excellent quality. Cast iron cookware retains heat well. It is convenient to prepare dishes that require constant warmth. Cast iron cookware is used to prepare pilaf, porridge and stew. The products in it retain a lot of useful properties. Carcinogenic substances are not formed in such food. By the way, it has been proven that cast iron cookware can enrich foods with useful iron elements.
For the oil industry , a complex and dangerous industry, pipes are made only from cast iron. The products are obtained with high performance qualities.
Cast iron is distinguished by its durability . Therefore, in our homes to this day you can see sinks and bathtubs that were made more than 50 years ago and are still being successfully used today.
Cast iron is very often used for artistic objects . Various works of art are made from it. Thus, the embankment of St. Petersburg is almost entirely decorated with cast iron items. Interesting and unusual fences, openwork branched gates and cast iron monuments are made from cast iron. All this became possible thanks to the good casting properties of this material. The items made practically do not wear out and look the same even after many years. It is not uncommon to find cast iron works of art within the walls of a museum.

It is especially pleasing that cast iron is well valued as a second-rate material. That is, if suddenly a cast iron item becomes unnecessary, you can turn it in for melting and get good money for it.

We will talk about the characteristics and areas of application of steels and cast irons (alloyed, antifriction, casting, etc.) below.

This video will tell you about the areas of application of cast iron:

This section will discuss the classification, marking (grades) and application of cast irons and their alloys.

Features of application

Gray cast iron is used in construction. White is too hard and brittle. It is smelted into malleable iron or steel.

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Cast iron has been used in construction since ancient times. Products made from it were of excellent quality if the production technology was strictly followed. Cast iron has always been produced by casting. The manufactured material should not have air pockets, molding lines or cracks.

In ancient times, supporting structures were made from cast iron, which were assembled piece by piece. First, the structural cast iron elements were cast, and then the bases were connected with fasteners. This method was especially often used in arched structures.
Cast iron has always been used to make sewer pipes, racks and post bases. Various designer items were made from it for homes.
Pipes in our houses, heating radiators, taps, water supply valves, fittings - all this is made using cast iron.
Plumbing products can be partially or completely made from the described material.
I would especially like to mention cast iron heating radiators. These devices are in high demand. Such heating radiators are durable, have high heat transfer and excellent heat-storing properties. They remain warm and give off heat to the room even an hour after being turned off. Compared to steel radiators, they lose heat twice as fast.
Today and in the past, grates were made from cast iron. With this strong material it was possible to create various shapes and designs. Interesting patterns and lines made cast iron products truly skillful. Some embankment decorations and palace fences have survived to this day. These works of art were made according to the ideas of famous masters. And cast iron made it possible to bring these ideas to life and preserve them to this day.

There is one caveat. Modern building materials have replaced cast iron. In some products, cast iron has been replaced with plastic. Today, practically no water fittings, sewer pipes, or plumbing fittings are manufactured. However, lids, fences and large sewer pipes are still made from cast iron.

Cast iron fittings

Cast iron

This type of cast iron has become popular due to its low fusibility. It melts even at low melting temperatures and easily fills the mold. Cast iron castings are quite durable and free of bubbles.

If we are talking about high-quality cast iron, then when it changes its state (from liquid to solid) it does not change its volume. This effect is achieved by adding special impurities to cast iron in the form of phosphorus, sulfur, manganese and silicon.

Due to its low fusibility, cast iron is used to make beautiful building parts in the form of various shapes. Subsequently, these parts are securely fastened with bolted connections.
In architecture there is no place without cast iron. Decorative cast iron elements can decorate any building and architectural monument.

Forged products

Cast iron is highly valued by blacksmiths. This material lends itself well to forging. This is all connected with the atomic lattice of the material, which has gaps. Making any products from it is as easy as shelling pears for a blacksmith. The following forged products have become a part of our lives:

Lanterns;
Stairs;
Decorative elements;
Gates;
Window grilles;
Front gardens;
Lantern poles.

Today, parks, offices and urban architecture are decorated with forged lattices, patterns, and applications.

Cast iron is resistant to corrosion. It is durable. And therefore, some cast iron elements have not lost their appearance to this day. It was noted that forged cast-iron stairs (both outside the house and inside), openwork drawings, sculptures, window grilles, gates and street lights look very impressive.

Cast iron staircase

In construction, cast iron has proven itself due to the following positive aspects:

Cast iron decorative elements produce a good visual effect.
Cast iron objects are not subject to corrosion processes.
Complex cast iron shapes can be produced very quickly.
Cast iron products have high strength.
Simple production process.
Making cast iron products is inexpensive.
Long service period.

The price of forged products depends on the amount of material used, the complexity of production, speed of execution, and company prices. The price is available to everyone. Everyone can decorate their homes with fashionable elements and grilles.

This video will tell you how cast iron and steel can be used:

Source: http://stroyres.net/metallicheskie/vidyi/chyornyie/chugun/primenenie-v-stroitelstve-i-drugih-oblastyah.html

The use of cast iron of different grades in various industries - SibNovStroy

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.

Iron production. Cast iron grades. Production technology

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

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

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://sibnovostroy.ru/oborudovanie/primenenie-chuguna-raznyh-marok-v-razlichnyh-otraslyah-promyshlennosti.html

Characteristics of malleable cast iron and its use in the national economy

Malleable cast iron (DC) is an alloy of iron and carbon with high ductility; products from it are obtained through the casting process.

Scheme of annealing white cast iron for malleable.

Malleable cast iron has high performance characteristics, which determine its use in many sectors of the national economy.

What are cast iron, graphite and cementite

Cast iron as such is a brittle material, an alloy of iron and carbon. The structure of cast iron contains a metal base and graphite inclusions; the alloy has eutectic properties, i.e.

the material can be melted, which determines its use as an alloy for casting. It may contain permanent and alloying impurities to improve physical and chemical properties.

Permanent impurities are phosphorus, sulfur, manganese, silicon, alloying ones are vanadium, aluminum, nickel, chromium. Carbon in cast iron is present as cementite or graphite.

Cementite is considered to be iron carbide, the phase and structural component of iron-carbon alloys: steel and cast iron, perlite, troostite, ledeburite, etc. This component is the most fragile ingredient in the alloy. It does not have plasticity and can withstand only minor elastic deformations.

Scheme of microstructures of graphitized cast irons: a) gray; b) high strength; c) malleable; d) with vermicular graphite.

The higher the percentage of cementite contained in the alloy, the lower its hardness and the greater its ductility.

Graphite is one of the most stable modifications of carbon, which can be present in the alloy not in a specific, but in various transition forms.

Depending on the form of graphite, cast irons are distinguished:

with lamellar graphite (ordinary white cast iron);
with vermicular graphite having zigzag veins (gray vermicular alloys);
with a spherical or globular ingredient (high-strength alloys);
with graphite in the form of flakes (malleable cast iron).

Cast iron is produced using special equipment - blast furnaces, electric furnaces, cupola furnaces.

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Graphitization, features of malleable cast iron, the concept of ferritic and pearlitic cast iron

In metallurgy, malleable cast iron is produced by graphitization of white hypoeutectic cast iron containing graphite in an amount of 2%-4.3%. During graphitization, annealing occurs in which cementite (iron carbide) decomposes, all or part of the carbon is converted into graphite (annealing carbon).

Carbon in cast iron is an important element that determines its mechanical properties; the higher the grade of cast iron, the lower the graphite content. Thanks to the technological process that introduces transformations into the composition of the alloy, cast iron acquires plasticity; its properties are between gray cast iron and steel.

Unlike steel, the alloy has fluidity, damping capacity (vibration absorption), and higher wear resistance.

Physical properties of malleable cast iron.

CC is produced in continuous chamber and tunnel furnaces.

The undeniable advantages of CC are:

uniformity;
no stress;
high mechanical and anti-corrosion properties;
excellent stability in humid air, flue gases, water;
plastic;
strength;
KCh is amenable to welding, caulking, pressing, cold and hot straightening, and cutting.

The high strength of CP is explained by the insignificant influence of the flake structure on the mechanical characteristics of the metal core. Products made from such an alloy are characterized by toughness and ductility, good resistance to impact loads, but the products are not forged, they are cast. The disadvantages of the material are the complex technology and the length of the production process.

According to the production method, CPs are classified into ferritic class F (black-core) and pearlite class P (white-core). Ferritic CN is produced by two-stage graphitizing annealing of white cast iron.

Pearlite grades are obtained by annealing in oxidizing environments. As a result, a change in the structure of cast iron and decarbonization occurs. This is one of the strongest types of cast iron.

In the alloy, the main high-strength mass with a metallic structure is complemented by the excellent shape of the graphite structure and its distribution.

Application of malleable cast iron in agriculture, automobile and shipbuilding

Mechanical properties of malleable cast iron according to GOST 1215-79.

CP is used in mechanical engineering, the main consumers being the areas of tractor construction and agricultural machinery. Ferritic cast iron has high viscosity and strength; it is used for the production of components that are not subject to abrasion, for example, flanges, levers, forks.

Various parts are made from pearlitic cast iron: diesel engine pistons, rocker arms, clutch assemblies, crankshafts, camshafts with cams, which, interacting with the pushers, operate the unit in a certain cycle, chain links, pawls, ridges, knife heads, brake drums and etc.

These products operate under the influence of static and dynamic loads and abrasion. The advantages of pearlitic cast iron are strength, wear resistance, high fatigue strength, resistance to high temperatures, and elimination of vibration.

CC is used in the automotive industry in the manufacture of thin-walled domestic castings operating under the influence of dynamic alternating loads.

Drives, gearboxes, wheel hubs, gears, gear housings, differentials, steering systems, engine and spring brackets, brake pads, rollers, linings, plugs, balancers, wings, cardan shafts, manifolds, etc. are made from the alloy. KCh is widely used in shipbuilding in the production of equipment for ships. It is used to make portholes, mast brackets, rowlocks, bridges, and models of steam and water fittings.

In the carriage industry they are used in the manufacture of spare parts for air brakes, bearings, brackets, traction couplings, shock-traction devices, brackets; These parts work under loads of impacts, bending, and wear.

Application of CP in various fields of industry

Cast collapsible chain made of malleable cast iron: a – design; b – method of assembly and disassembly.

In the electrical industry, CPs are used to produce terminals, insulator hooks, caps, and wire holders. Products are subject to bending and shock loads. In the machine tool industry and textile engineering, CP are used to produce gears, forks, spokes and all kinds of parts for paper spinning machines, i.e. those parts that are subject to static and dynamic loads, wear, and friction. They use grades of anti-friction gray malleable cast iron, which ensures minimal friction at the points of contact of the parts.

Decarbonized CC grades are used in the production of sanitary and construction equipment and various parts. Plumbing products can be: bends for water supply and sewerage, flange adapters for connecting cast iron systems with plastic ones, valves, pipes, heating radiators. These products are exposed to aquatic environments. In gas systems, CN is used when producing fittings for connecting pipes at branching points.

Also, various brands of KCh can be used in the defense industry, landscape design when creating decorative elements: elaborate hedges, benches, gates, wickets; in the manufacture of decorative furniture exposed to atmospheric precipitation: tables and chairs for terraces, gazebos of country houses; in the manufacture of household and industrial equipment: bathtubs, gas stoves, washing machines, dishes (pots, pans).

Due to its high-strength properties, ductile cast iron is used as a structural material in many industries.

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Source: https://moyakovka.ru/izdeliya/kovkii-chugun-primenenie.html

How to choose good cast iron cookware and properly care for it

When cookware with non-stick Teflon and ceramic coatings appeared, many decided that cast iron was outdated and could not stand up to the competition. And in vain. To see this, just look into the kitchen of any restaurant. There is unlikely to be a place for utensils with Teflon or ceramic coating, but ordinary cast iron cauldrons and frying pans will definitely be there.

Let's figure out why chefs and ordinary people love cast iron cookware so much.

Environmental friendliness . Unlike modern analogues, good old cast iron is an environmentally friendly material that is completely safe for health. No chemical compounds are used in the manufacture of cookware, and the non-stick coating is created naturally during cooking.
Durability . Cast iron cookware is practically eternal. It serves for decades, only becoming better over time. It cannot be spoiled: it is enough to clean and heat the dishes so that they become as good as new.
Thermal conductivity . Due to its porous structure, cast iron heats up slowly, but at the same time retains heat well, distributing it evenly over the entire surface, and provides higher temperatures compared to aluminum and steel.
Versatility . Cast iron cookware is suitable for both gas and electric stoves, including induction. You can cook, fry, stew and bake in the oven.
Taste of food . Thanks to uniform heating, food does not burn, is cooked on all sides without remaining raw, and has a special taste.

The only disadvantages of cast iron cookware include heavy weight, fragility and certain nuances in care. Due to the large thickness of the walls, the average frying pan weighs about two kilograms. For the same reason, if you drop a frying pan on the floor, a crack may form in it, or even a piece may break off. In addition, cast iron cookware needs to be looked after: properly cleaned and stored.

How to choose good cast iron cookware

On the market there are cast iron frying pans, pancake pans, stewpans, fryers, saucepans, cauldrons, and cauldrons from various manufacturers. To choose high-quality cookware in which you will enjoy cooking for many years, follow the following algorithm when purchasing.

1. Decide on the purpose

First of all, decide what the cast iron cookware will be used for. In the same pan you can fry eggs, stew meat and bake pancakes. But it’s better when each purpose has its own, ideally suited kitchen utensils. This will not only eliminate the need for thorough cleaning, but will also allow you to achieve the necessary cooking conditions.

For example, for pancakes you need a thin frying pan, for stewing - a deep frying pan, for frying meat - with a grooved bottom, for baking in the oven - with cast handles. Try to choose the optimal volume and remember that large dishes are not only heavier, but also require a more powerful stove.

For cauldrons, the shape of the bottom is also very important. Flat is more stable, but transfers heat to the walls worse. Round is better in this regard, but may require an additional stand for installation on the stove. So it is better to use it on an open fire.

Cast iron

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Cast iron cookware comes with or without coating. The traditional one is simply cast from cast iron and then ground to remove casting flaws. After purchase, it must be ignited over a fire and treated with oil to create a natural non-stick coating.

You cannot leave food in such dishes for a long time: cast iron oxidizes and rusts. Frying pans, cauldrons and everything else must be dried well after each use and periodically lubricated with oil.

Enameled cast iron

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This type of cookware has a protective enamel coating on the inside and outside. Enameled cast iron is considered to be better than regular cast iron, but in fact it has both advantages and disadvantages.

Thanks to the enamel coating, the dishes look more attractive and come in many colors. In addition, it does not rust and you can leave food in it for a long time. It is easier to clean and allows you to use almost no detergents.

At the same time, due to the properties of enamel, such utensils require careful handling. To prevent the coating from cracking, do not heat and cool the dishes sharply, knock on the side with a slotted spoon, or scrape off burnt-on food debris with hard objects or abrasive detergents.

What material to choose is up to you. With ordinary cast iron there is a little more fuss, but it is almost indestructible. Enameled is more beautiful and in some places more practical, but needs very careful handling.

3. Check for flaws

A crack in an old frying pan. seriouseats.com

Despite the simplicity of making cast iron cookware, sometimes casting defects still occur, which not only do not decorate, but can also ruin the product over time. Usually manufacturers in the budget segment suffer from defects, although defects can also be found in more expensive cookware.

Before purchasing, turn the cauldron or frying pan in your hands and carefully inspect it from all sides. Under no circumstances should there be cracks on the surface or attempts to melt them. The dishes should be smooth and well polished, without sagging or cavities (recesses).

Enameled cast iron must have a perfectly smooth coating without scratches, abrasions, blisters and other defects, which over time can turn into areas of damage and destroy the coating, making the cookware unsuitable for use.

4. Select handle material

They can be cast, wooden and polymer, as well as removable and non-removable. Of course, each type has its own advantages and disadvantages.

Cast ones are good because they are not afraid of high temperatures and allow you to use the dishes in the oven. They get very hot during cooking, so you can only handle them with an oven mitt.
Wooden ones do not heat up, are environmentally friendly, but less durable. Cookware with such handles cannot be used in the oven unless they are removable.
Polymer handles do not heat up and allow the dishes to be used in the oven, but can break off if handled carelessly.

5. Select a cover

Cauldrons, saucepans, and casserole dishes are usually sold with lids. Frying pans and roasting pans most often come without them, but this is not necessarily a bad thing: this way you don’t overpay for a lid and can choose a suitable one from other utensils that you have in the kitchen.

At first glance, cast iron lids seem to be the best option, but this is not always the case. Their disadvantage is that they are very massive and take away heat, affecting the preparation of a dish, such as pilaf. Glass lids are more advantageous in this regard, since they have lower thermal conductivity and allow you to monitor the cooking process.

How to prepare dishes for use

The difference between exclusively cast iron cookware and the rest is that before cooking you need to thoroughly heat it and make a non-stick coating.

Enameled cast iron does not require any preparation. Moreover, strong heat can damage the enamel!

At first glance, calcination seems like a complicated procedure and scares off many buyers. However, there is no need to be afraid. In order for the dishes to serve for many years, you only have to work hard once.

In addition, if something goes wrong, the frying pan or cauldron will not be damaged. It will be enough to clean the surface and repeat the procedure. To get it right the first time, do the following.

If the dishes are not smooth enough, it is advisable to sand them first. It is best to use a metal brush attachment for a screwdriver or angle grinder, and then go over it with medium to fine sandpaper. After treatment, the surface will become gray, smooth and shiny.

Place the dishes on high heat (if the stove is electric, select the maximum temperature) and be sure to turn on the hood or open the window.

After a few minutes, the remaining oil that was used to process the cast iron in production will begin to burn out and smoke will begin to appear. This is fine.

Continue heating the cookware for 20–30 minutes until it stops smoking and the metal turns gray. The cauldron and other tall dishes need to be rotated additionally to thoroughly warm the walls.

Let the cast iron cool slightly, shake out the scale and thoroughly wipe the surface with a paper towel soaked in vegetable oil. Change towels until all the soot is removed, and then wipe dry again.

Apply a layer of vegetable oil to the cleaned surface and rub well with a brush. It’s better to take refined one, but regular one will do just fine. Also treat the top edges and outer surface with a small amount of oil.

Place the greased pan over medium heat. This time there is no need to heat it too much. As soon as smoke starts to emerge from the dishes, lower the temperature and spread the oil with a brush so that the baking film lies in an even layer over the entire surface.

Continue heating the cast iron for about 20 minutes until the oil layer stops sticking. Turn off the stove and let the pan cool completely, then brush the inside again with a small amount of oil using a brush or paper towel.

Now you can start cooking.

To create a non-stick coating, you can heat oiled pans in the oven rather than on the stove. In this case, the process will take much longer, but there will be less smoke. The heating method does not affect the quality of the coating in any way: both the stove and the oven will give the same result.

If desired, the procedure for creating an oil film can be repeated three to five times - this will make the natural non-stick coating stronger and more effective. However, it will improve with every cooking.

How to properly care for cast iron cookware

All the most difficult things are left behind. Now a cast iron frying pan or cauldron can be treated almost like any ordinary cookware. However, there are still some nuances of cleaning and storage.

Regular cast iron

Uncoated cast iron cookware oxidizes and rusts from contact with moisture, so it should not be left with food for long periods of time. You can wash the frying pan after dinner or an hour or two later, but you can’t throw it on the stove with leftover food overnight. The dishes will not be lost because of this, but they will have to be cleaned and calcined again.

In order not to spoil the non-stick layer, it is better to use wooden or plastic ones instead of metal skimmers and spatulas.

Also, cast iron is afraid of temperature changes, so you should not expose a hot frying pan to a stream of cold water. If you are in a hurry, use hot water, or better yet, let the dishes cool. It may be able to withstand a couple of such contrasting showers, but on the third, it will most likely crack.

It is not recommended to use metal sponges or aggressive detergents for cleaning. They negatively affect the coating and oxidize the metal. Additionally, chemicals can be absorbed into cast iron due to its porous structure. For the same reason, it is not recommended to use a dishwasher.

Most stains are easily washed off with hot water. Sometimes it is enough to rinse the dishes with boiling water, and when they cool down, wipe them dry with a paper towel. If the food is burnt, just briefly fill the dish with water: everything will come off.

After washing, the frying pan or cauldron must be dried by wiping it well with a paper towel or simply placing it on the stove for a few seconds. If this is not done, it may rust. Also, from time to time the dishes need to be lubricated with a small amount of oil.

Gray cast iron products

An alloy of iron containing carbon is called cast iron. In some cases, alloying additives are added to the composition, affecting its consumer qualities. Cast iron is a metal that is used primarily in ferrous metallurgy. It is not only used to produce steel, it is also in demand in the manufacture of forged artistic parts.

Gray cast iron

Properties of cast iron

Cast iron is an alloy of iron with carbon, as well as other elements.

Characteristics of cast iron

White cast iron: properties, application, structure and features

Initially, cast iron technology was first mastered in China back in the 10th century, after which it became widespread in other countries of the world. The basis of cast iron is an alloy of iron with carbon and other components.

A distinctive feature is that cast iron contains more than 2% carbon in the form of cementite, which is not found in other metals.

A prominent representative of such an alloy is white cast iron, which is used in mechanical engineering for the manufacture of parts, in industry and in everyday life.

Appearance

Where is cast iron used?

23/01/2015

Cast iron products have been known to a wide circle since ancient times and therefore, in our time, it is difficult to meet a person who does not know, have not heard of or have not encountered this alloy in his life. It is everywhere and everywhere - its application is so widespread. Cast iron is an iron alloy with a low carbon content, into which various additives are introduced, which greatly improves its quality.

Advantages of cast iron

The use of cast iron and products made from it in construction and other areas

Cast iron has always been used for the manufacture of parts and heavy industrial . It was used in metallurgy and machine tool building. Moreover, this material was taken in very large quantities. It was used as the main one for small items and for large items, the weight of which reached hundreds of tons.
in mechanical engineering . This is the type that is always taken for the manufacture of critical parts. Cast iron machine products resist vibration and vibration well.
In the automotive industry, cylinder blocks are made from cast iron. These are critical parts that must have high strength and wear resistance. Cast iron helps to meet these qualities. To make these indicators optimal, special additives in the form of graphite are added to cast iron. Graphite increases the strength properties of the alloy several times. Additives make it possible to perfect cast iron and use it in the manufacture of diesel crankshafts.
Brake pads are made from cast iron . We know that these parts operate under high friction. Cast iron helps them withstand these harsh conditions. In addition, rollers for flour-grinding and paper-making machines are made from cast iron.
Cast iron products work well at low temperatures . For this purpose, malleable cast iron is used. It is used to make parts of tractors and complex mechanisms that will subsequently operate under harsh conditions.
Cast iron is widely used to make household items . This material is very popular among our population. Cast iron pots, frying pans, cauldrons can be found both in an ordinary kitchen and in a restaurant's arsenal of dishes. This is truly unique tableware.
Any housewife knows about a cast iron frying pan, which has excellent quality. Cast iron cookware retains heat well. It is convenient to prepare dishes that require constant warmth. Cast iron cookware is used to prepare pilaf, porridge and stew. The products in it retain a lot of useful properties. Carcinogenic substances are not formed in such food. By the way, it has been proven that cast iron cookware can enrich foods with useful iron elements.
For the oil industry , a complex and dangerous industry, pipes are made only from cast iron. The products are obtained with high performance qualities.
Cast iron is distinguished by its durability . Therefore, in our homes to this day you can see sinks and bathtubs that were made more than 50 years ago and are still being successfully used today.
Cast iron is very often used for artistic objects . Various works of art are made from it. Thus, the embankment of St. Petersburg is almost entirely decorated with cast iron items. Interesting and unusual fences, openwork branched gates and cast iron monuments are made from cast iron. All this became possible thanks to the good casting properties of this material. The items made practically do not wear out and look the same even after many years. It is not uncommon to find cast iron works of art within the walls of a museum.

It is especially pleasing that cast iron is well valued as a second-rate material. That is, if suddenly a cast iron item becomes unnecessary, you can turn it in for melting and get good money for it.

We will talk about the characteristics and areas of application of steels and cast irons (alloyed, antifriction, casting, etc.) below.

This video will tell you about the areas of application of cast iron:

This section will discuss the classification, marking (grades) and application of cast irons and their alloys.

Features of application

Gray cast iron is used in construction. White is too hard and brittle. It is smelted into malleable iron or steel.

https://www.youtube.com/watch?v=Wj3yX7R9dE4

In ancient times, supporting structures were made from cast iron, which were assembled piece by piece. First, the structural cast iron elements were cast, and then the bases were connected with fasteners. This method was especially often used in arched structures.
Cast iron has always been used to make sewer pipes, racks and post bases. Various designer items were made from it for homes.
Pipes in our houses, heating radiators, taps, water supply valves, fittings - all this is made using cast iron.
Plumbing products can be partially or completely made from the described material.
I would especially like to mention cast iron heating radiators. These devices are in high demand. Such heating radiators are durable, have high heat transfer and excellent heat-storing properties. They remain warm and give off heat to the room even an hour after being turned off. Compared to steel radiators, they lose heat twice as fast.
Today and in the past, grates were made from cast iron. With this strong material it was possible to create various shapes and designs. Interesting patterns and lines made cast iron products truly skillful. Some embankment decorations and palace fences have survived to this day. These works of art were made according to the ideas of famous masters. And cast iron made it possible to bring these ideas to life and preserve them to this day.

Cast iron fittings

Cast iron

This type of cast iron has become popular due to its low fusibility. It melts even at low melting temperatures and easily fills the mold. Cast iron castings are quite durable and free of bubbles.

Due to its low fusibility, cast iron is used to make beautiful building parts in the form of various shapes. Subsequently, these parts are securely fastened with bolted connections.
In architecture there is no place without cast iron. Decorative cast iron elements can decorate any building and architectural monument.

Forged products

Lanterns;
Stairs;
Decorative elements;
Gates;
Window grilles;
Front gardens;
Lantern poles.

Today, parks, offices and urban architecture are decorated with forged lattices, patterns, and applications.

Cast iron staircase

In construction, cast iron has proven itself due to the following positive aspects:

Cast iron decorative elements produce a good visual effect.
Cast iron objects are not subject to corrosion processes.
Complex cast iron shapes can be produced very quickly.
Cast iron products have high strength.
Simple production process.
Making cast iron products is inexpensive.
Long service period.

This video will tell you how cast iron and steel can be used:

Source: http://stroyres.net/metallicheskie/vidyi/chyornyie/chugun/primenenie-v-stroitelstve-i-drugih-oblastyah.html

The use of cast iron of different grades in various industries - SibNovStroy

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.

Iron production. Cast iron grades. Production technology

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

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

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.

THIS IS INTERESTING: How a magnet is made

Production technology

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.

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.

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

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

A little about foundry

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

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

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://sibnovostroy.ru/oborudovanie/primenenie-chuguna-raznyh-marok-v-razlichnyh-otraslyah-promyshlennosti.html

Characteristics of malleable cast iron and its use in the national economy

Malleable cast iron (DC) is an alloy of iron and carbon with high ductility; products from it are obtained through the casting process.

Scheme of annealing white cast iron for malleable.

Malleable cast iron has high performance characteristics, which determine its use in many sectors of the national economy.

What are cast iron, graphite and cementite

Cast iron as such is a brittle material, an alloy of iron and carbon. The structure of cast iron contains a metal base and graphite inclusions; the alloy has eutectic properties, i.e.

the material can be melted, which determines its use as an alloy for casting. It may contain permanent and alloying impurities to improve physical and chemical properties.

Permanent impurities are phosphorus, sulfur, manganese, silicon, alloying ones are vanadium, aluminum, nickel, chromium. Carbon in cast iron is present as cementite or graphite.

Scheme of microstructures of graphitized cast irons: a) gray; b) high strength; c) malleable; d) with vermicular graphite.

The higher the percentage of cementite contained in the alloy, the lower its hardness and the greater its ductility.

Graphite is one of the most stable modifications of carbon, which can be present in the alloy not in a specific, but in various transition forms.

Depending on the form of graphite, cast irons are distinguished:

with lamellar graphite (ordinary white cast iron);
with vermicular graphite having zigzag veins (gray vermicular alloys);
with a spherical or globular ingredient (high-strength alloys);
with graphite in the form of flakes (malleable cast iron).

Cast iron is produced using special equipment - blast furnaces, electric furnaces, cupola furnaces.

All about wood and woodworking - 1poderevu.ru.

Graphitization, features of malleable cast iron, the concept of ferritic and pearlitic cast iron

Unlike steel, the alloy has fluidity, damping capacity (vibration absorption), and higher wear resistance.

Physical properties of malleable cast iron.

CC is produced in continuous chamber and tunnel furnaces.

The undeniable advantages of CC are:

uniformity;
no stress;
high mechanical and anti-corrosion properties;
excellent stability in humid air, flue gases, water;
plastic;
strength;
KCh is amenable to welding, caulking, pressing, cold and hot straightening, and cutting.

Pearlite grades are obtained by annealing in oxidizing environments. As a result, a change in the structure of cast iron and decarbonization occurs. This is one of the strongest types of cast iron.

In the alloy, the main high-strength mass with a metallic structure is complemented by the excellent shape of the graphite structure and its distribution.

Application of malleable cast iron in agriculture, automobile and shipbuilding

Mechanical properties of malleable cast iron according to GOST 1215-79.

CC is used in the automotive industry in the manufacture of thin-walled domestic castings operating under the influence of dynamic alternating loads.

Application of CP in various fields of industry

Cast collapsible chain made of malleable cast iron: a – design; b – method of assembly and disassembly.

Also, various brands of KCh can be used in the defense industry, landscape design when creating decorative elements: elaborate hedges, benches, gates, wickets; in the manufacture of decorative furniture exposed to atmospheric precipitation: tables and chairs for terraces, gazebos of country houses; in the manufacture of household and industrial equipment: bathtubs, gas stoves, washing machines, dishes (pots, pans).

Due to its high-strength properties, ductile cast iron is used as a structural material in many industries.

Source: https://moyakovka.ru/izdeliya/kovkii-chugun-primenenie.html

How to choose good cast iron cookware and properly care for it

Let's figure out why chefs and ordinary people love cast iron cookware so much.

Environmental friendliness . Unlike modern analogues, good old cast iron is an environmentally friendly material that is completely safe for health. No chemical compounds are used in the manufacture of cookware, and the non-stick coating is created naturally during cooking.
Durability . Cast iron cookware is practically eternal. It serves for decades, only becoming better over time. It cannot be spoiled: it is enough to clean and heat the dishes so that they become as good as new.
Thermal conductivity . Due to its porous structure, cast iron heats up slowly, but at the same time retains heat well, distributing it evenly over the entire surface, and provides higher temperatures compared to aluminum and steel.
Versatility . Cast iron cookware is suitable for both gas and electric stoves, including induction. You can cook, fry, stew and bake in the oven.
Taste of food . Thanks to uniform heating, food does not burn, is cooked on all sides without remaining raw, and has a special taste.

How to choose good cast iron cookware

1. Decide on the purpose

2. Select housing material

Cast iron

emigration.center

You cannot leave food in such dishes for a long time: cast iron oxidizes and rusts. Frying pans, cauldrons and everything else must be dried well after each use and periodically lubricated with oil.

Enameled cast iron

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At the same time, due to the properties of enamel, such utensils require careful handling. To prevent the coating from cracking, do not heat and cool the dishes sharply, knock on the side with a slotted spoon, or scrape off burnt-on food debris with hard objects or abrasive detergents.

3. Check for flaws

A crack in an old frying pan. seriouseats.com

4. Select handle material

They can be cast, wooden and polymer, as well as removable and non-removable. Of course, each type has its own advantages and disadvantages.

Cast ones are good because they are not afraid of high temperatures and allow you to use the dishes in the oven. They get very hot during cooking, so you can only handle them with an oven mitt.
Wooden ones do not heat up, are environmentally friendly, but less durable. Cookware with such handles cannot be used in the oven unless they are removable.
Polymer handles do not heat up and allow the dishes to be used in the oven, but can break off if handled carelessly.

5. Select a cover

How to prepare dishes for use

The difference between exclusively cast iron cookware and the rest is that before cooking you need to thoroughly heat it and make a non-stick coating.

Enameled cast iron does not require any preparation. Moreover, strong heat can damage the enamel!

In addition, if something goes wrong, the frying pan or cauldron will not be damaged. It will be enough to clean the surface and repeat the procedure. To get it right the first time, do the following.

Place the dishes on high heat (if the stove is electric, select the maximum temperature) and be sure to turn on the hood or open the window.

After a few minutes, the remaining oil that was used to process the cast iron in production will begin to burn out and smoke will begin to appear. This is fine.

Continue heating the cookware for 20–30 minutes until it stops smoking and the metal turns gray. The cauldron and other tall dishes need to be rotated additionally to thoroughly warm the walls.

Let the cast iron cool slightly, shake out the scale and thoroughly wipe the surface with a paper towel soaked in vegetable oil. Change towels until all the soot is removed, and then wipe dry again.

Apply a layer of vegetable oil to the cleaned surface and rub well with a brush. It’s better to take refined one, but regular one will do just fine. Also treat the top edges and outer surface with a small amount of oil.

Now you can start cooking.

To create a non-stick coating, you can heat oiled pans in the oven rather than on the stove. In this case, the process will take much longer, but there will be less smoke. The heating method does not affect the quality of the coating in any way: both the stove and the oven will give the same result.

How to properly care for cast iron cookware

All the most difficult things are left behind. Now a cast iron frying pan or cauldron can be treated almost like any ordinary cookware. However, there are still some nuances of cleaning and storage.

Regular cast iron

In order not to spoil the non-stick layer, it is better to use wooden or plastic ones instead of metal skimmers and spatulas.

It is not recommended to use metal sponges or aggressive detergents for cleaning. They negatively affect the coating and oxidize the metal. Additionally, chemicals can be absorbed into cast iron due to its porous structure. For the same reason, it is not recommended to use a dishwasher.

Source: `https://Lifehacker.ru/chugunnaya-posuda/`

Gray cast iron products

Gray cast iron

For mechanical engineering, gray cast iron containing graphite is mainly used. Parts made from such material do not react to stresses; they absorb vibrations that occur when mechanisms vibrate. Critical parts are made from it

Bushings;
Machine beds;
Heavy bases.

It began to be used as a structural material in almost all enterprises of the mechanical engineering industry. The following industries became the largest consumers of gray cast iron

Automotive industry;
Machine tool industry;
Metallurgy;
Sanitary.

Tractor parts made from gray cast iron reach 20% of the total number of parts. This use of this alloy is associated with high wear resistance. It does not lift up in case of high friction and lack of lubrication, in other words, it has damping ability . It is made from:

Blocks;
Bearing caps;
Brake discs;
Ferrado;

To manufacture the cylinder head of various engines, of low-alloy alloy :

The main requirements for the midrange during the production of liners were:

Pearlite structure;
Graphite;
High hardness.

For car engines of any design, cylinder liners made of a special alloy are used. In most cases, its phosphorous fraction is used.

Diesel engines during operation create a large load on the cylinder block , so alloy cast iron is used for them. Cylinder heads are made from high carbon alloy grades,

The same requirements are observed in the manufacture of liner castings, the material of which is a low-alloy alloy. The chemical composition of this material depends on several technological characteristics:

Melting method;
Casting dimensions;
Manufacturability of form.

Cars are equipped with cast iron camshafts, which are highly wear-resistant. This parameter is achieved thanks to surface hardening to which the metal is subjected.

When a part is operated at high speeds, when dry friction occurs, it is necessary to have increased wear resistance of the material and a high coefficient of friction. It is in such conditions that this alloy is simply irreplaceable.

Brake drums operating in such conditions are made from SCh20. When a part experiences high loads and thermal cracks may appear, a special heat-resistant alloy with a high carbon content and a high level of alloying is used.

For particularly severe conditions, parts made of pearlitic cast iron are installed. It contains vermicular graphite.

The rotation of the flywheel during operation reaches 7000 rpm. This speed causes tensile stresses to appear. The rotating surface of the flywheel constantly touches the working surface of another part. Such friction causes a strong release of heat, resulting in thermal cracks that negatively affect the strength of the part.

To increase strength , given the large weight of the flywheel and the size of its cross-section, it is made from various grades:

It must provide a workpiece strength above 250 N/mm2. Sometimes SCh 35 has strength that is not enough to ensure normal operation of the flywheel. In this case, cast iron is used, to which nodular graphite is added.

Passenger cars boast cast iron caps covering the main bearings . This design is found in most cases on cars with a carburetor engine. To ensure a pearlite structure, as well as high hardness exceeding 200 HB, SCh25 is used for the manufacture of bearing caps.

Manufacturing of collectors

In a car, the exhaust manifolds are exposed to exhaust gases, the temperature of which reaches 90 degrees. Collectors under the influence of an aggressive environment oxidize, deform and crack.

The use of gray cast iron ensures durability of such parts and high efficiency. Due to the fact that the thickness of the collector walls is very small, less than 7 mm, SCh15 is used for their manufacture. To increase its heat resistance, cast iron is alloyed with chromium or nickel additives.

For the manufacture of collectors experiencing high thermal loads, the following is used:

Ductile iron;
With additives of spherical graphite;

All of the above materials have high heat resistance and resistance to aggressive environments, alkalis and oxides.

Machine tool industry

In the machine tool industry, a large number of cast parts are made from gray cast iron, operating in various conditions, the weight of which can reach 100 tons , with a maximum wall thickness of 200 millimeters.

The classification of such cast parts in the machine tool industry, depending on the designs and the operating conditions created, corresponds to the current standard.

For each part, a special grade of cast iron is selected . It depends on the following parameters:

Class of the workpiece;
Wall thickness;
Hardness;
Microstructures.

How to distinguish cast iron from steel visually?

Considering the specifics of many machine-tool parts, which work mainly on rigidity, for their manufacture they prefer to use cast iron, which has increased hardness and fairly low ductility.

The chemical composition of such cast irons is high in manganese and low in carbon. To obtain high hardness of cast iron, alloying and other technological processes are used.

SSP blanks are widely used in metallurgical equipment:

Sheet rolls;
Molds;
Slag bowls.

Plumbing

A lot of cast iron products are used in plumbing. Made from cast iron:

Heating radiators;
Pipes;
Fitting;
Sinks;
Kitchen sinks.

And today cast iron bathtubs remain in demand, which are distinguished by high strength , durability and reliability. Such products can be used for decades. They retain their original appearance and do not require replacement.

Craftsmen make artistic masterpieces from cast iron. For example, the embankments of St. Petersburg are decorated with cast iron parts. Walking along the streets of the city you can see openwork gates and original cast-iron fences. In the parks you can see cast iron monuments.

Application of Ductile Iron

This material has excellent damping properties and is capable of excellent performance at very low temperatures. This type of cast iron is used in the production of critical parts for tractors, as well as cars, which will have to perform their work in difficult climatic conditions.

Parts made of malleable cast iron have also found their application in the electrical industry . It is made from:

Terminals;
Insulator hooks;
Wire holders.

Such products cope well with force loads; they can bend under mechanical stress.

In textile engineering , ductile iron is used in the manufacture of:

Gears;
Forks
Spokes;
Parts for paper spinning machines.

In other words, for parts experiencing large static loads, subject to friction and rapid wear. For such products, anti-friction malleable cast iron is used, which is capable of creating minimal friction where there is maximum contact between the parts.

Source: https://varimtutru.com/izdeliya-iz-serogo-chuguna/

Properties of cast iron

Cast iron is an alloy of iron with carbon, as well as other elements.

Characteristics of cast iron

An important factor in the production of cast iron is that the minimum amount of carbon in the alloy is 2.14% or more. If the carbon content in the alloy is below the specified amount, then this alloy is not cast iron, but is called steel. The production process for steel and cast iron is approximately the same. The main difference between these two alloys is the quantitative carbon content in their composition.

Since cast iron contains more carbon than steel, cast iron is a very strong but brittle material. While steel is very flexible. It is the high carbon content in cast iron that gives this material its exceptional hardness, which is as much as 7.5 on the Mohs scale.

This indicator is significantly higher than that of quartz, however, less than that of diamond, but only by 2.5 points.

The carbon in cast iron can be cementite and graphite. It is the shape of graphite and the quantitative content of cementite in the alloy that determines the type of cast iron. Thus, cast iron is divided into white, gray, malleable and high-strength. The chemical composition of cast iron, which contains impurities such as silicon, manganese, sulfur and phosphorus, is almost always constant.

However, in some cases, cast iron may also contain the following alloying elements: chromium, nickel, aluminum, vanadium and others. These components are introduced into the alloy in order to give it greater strength, wear resistance, heat resistance, corrosion resistance, and non-magneticity. Cast iron containing these impurities is called alloy cast iron.

The quantitative content of these impurities in the alloy determines the degree of alloying. Depending on this, there are:

low alloy cast iron. It contains less than 2.5% of all alloying impurities;
medium alloy cast iron. Here the impurities are about 2.5 - 10%;
highly alloyed, containing more than 10% alloying elements.

The chemical characteristics of alloy cast irons are the main factor for their classification. Thus, among alloyed cast irons there are:

aluminum cast iron. It contains aluminum in amounts from 0.6 to 31%. This cast iron is stronger, more heat-resistant, corrosion-resistant, and also has high wear resistance. The use of this alloy is appropriate where work is carried out in an aggressive environment and at high temperatures - thermal furnaces, chemical equipment, gas engines.
nickel cast iron. It contains nickel in amounts ranging from 0.3-0.7% to 19-21%. nickel directly affects the shape of graphite precipitates in the structure of nickel cast iron. This alloy has such properties as high resistance to corrosion, high resistance to the effects of both high and fairly low temperatures on the material (heat resistance and cold resistance), and is also able to withstand exposure to such an aggressive environment as sea water. The latter property of nickel cast iron determines the high demand for this material in shipbuilding, as it is used for the manufacture of parts operating in sea water.
chromium cast iron. This alloy contains about 32% chromium. This type of alloy cast iron has the following properties: heat resistance, corrosion resistance, wear resistance.

It is worth noting that in general the cost of alloy cast iron is significantly lower than the cost of stainless steel. In addition, they have good casting properties. In this regard, products made from this alloy are very durable, high quality, and at the same time economical.

Pig iron is extracted through the process of smelting iron ore in blast furnaces at temperatures ranging from 1150 to 12000C.

History of cast iron

Cast iron has been known to mankind since ancient times, which go back to the era BC. This is evidenced by numerous archaeological finds, among which there are both cast iron objects and the cheese furnaces themselves, in which, in fact, people received this material.

However, iron is far from the first historical metal with which humanity became acquainted. Initially, people used native copper, which was mined in shallow mines. However, despite the appearance of metal in people's lives, stone remained very popular for quite a long time.

Later, people learned to make bronze, and only in VI-V BC iron appeared in people's lives, and with it steel and cast iron.

The birthplace of cast iron products is China. It was there that the technology of cast iron was first mastered and this term was born, which later came to Russia through Tatar-Mongol mediation. Thus, the first cast iron products also appeared in China. It was a wide variety of everyday items, kitchen utensils, as well as coins.

The wok frying pan, quite popular today, was one of the first to be made in China from cast iron. In those distant times, it was a vessel whose diameter reached one meter. This frying pan also had very thin walls.

Its cost was quite high, however, despite this, this kitchen equipment was extremely popular and in demand in large Chinese families.

In addition, archaeologists find unique things cast from cast iron, among which we should note a cast iron lion, which is 6 meters high and 5 meters long. According to scientists, this statue was cast in one go. This indicates that in those distant prehistoric times, in the absence of modern high-quality technologies, Chinese metallurgists achieved enormous skill in working with metals, in particular with cast iron.

A rather interesting and somewhat unusual fact is that it is believed that malleable cast iron began to be produced only in the 19th century AD, despite the fact that archaeologists have found cast iron swords made in the pre-Christian era.

Russia and Europe became acquainted with cast iron more than a century later, namely only in the 14th – 16th centuries. At this time, cast iron was the main material for the production of artillery shells and weapons. And only in the 17th century the use of cast iron expanded significantly. This was facilitated by the development of the metallurgical industry.

Gradually, the era of artillery use of cast iron ended and the era of artistic casting began - the new capital of the Russian Empire was decorated everywhere with cast fences, benches, and other elements of fine cast iron.

Cast iron also caused changes in the stove business, as cast iron valves and stove doors were replaced, which had the significant advantage of resistance to high temperatures, as well as tightness, which did not allow stove smoke to escape from the stove and fill the room with smoke.

Russian metallurgists were considered the best in those days. They mastered many cast iron processing technologies, which were constantly adopted by English, French and German craftsmen.

Today, in the era of nanotechnology and technological progress, when new materials appear every year, the development of metallurgy does not stop and continues to move forward. And after more than two thousand years, humanity has not been able to find a material that could replace cast iron. It continues to be used to make various objects that surround people.

Use of cast iron

The properties of cast iron are so unique that to date no more suitable material has been found that could replace this alloy. In addition, cast iron is a fairly cheap material.

In this regard, the use of cast iron remains wide and varied. The use of cast iron is especially appropriate where parts with complex shapes and high strength must be manufactured.

In this regard, cast iron has found its wide application in the following areas of human activity:

Automotive industry. In this case, cast iron with vermicular graphite is used. It is the main material for the manufacture of crankshafts of diesel engines, as well as cylinder blocks of internal combustion engines. Due to the graphite content, the strength of the alloy increases significantly, which is the main reason for the popularity of cast iron in this industry.
plumbing equipment. As with the automotive industry, graphite cast iron is also used. This material is perfect for the production of pipes used for both drainage and water supply. It is also actively used in the production of bathtubs, sinks, washstands, fittings and much more. In this case, the products are highly reliable, do not require any specific care, and retain their original appearance for a long period.
Oil and gas industry. Not only water pipes are made from cast iron, but also pipes for transporting, injecting and pumping out oil and gas. The main reason for using cast iron in this industry is that cast iron products have fairly high performance qualities.
heating. Pipes and heating radiators are made from cast iron. The use of the material in this case is due to its high heat transfer, as well as good heat-storing properties, which is very important and beneficial. After turning off the heating, after an hour, cast iron pipes are able to continue to radiate heat at a third of their original power. And here cast iron completely prevails over steel, which cannot boast of such qualities, because steel pipes cool twice as fast.
kitchen tools. The material has large pores, due to which it has the ability to absorb fat during cooking. In this regard, pots, cauldrons and frying pans are made from cast iron, the non-stick properties of which become better and better over the years. In addition, scientists have proven that when cooking in cast iron cookware, food is enriched with beneficial nutritional properties. In addition, cast iron cookware can prevent carcinogens during further storage of food.

Fences and gratings, spiral staircases, balconies, gazebos, fireplaces, lamps, pillars, lanterns, sculptures, etc. are made from cast iron.

How to identify cast iron

Knowing the material from which certain objects are made is very important. For example, it is necessary to carry out repair work on certain automotive components, individual parts or other items. This is due, first of all, to the fact that different materials lend themselves to different types and methods of processing (for example, welding, drilling, etc.).

So, cast iron can in some cases be determined visually. However, this method is suitable if there are any cracks, chips or tears in the material. If any such defects are present, it should be carefully inspected. A cast iron part that is broken or cracked will be painted dark gray and have a matte surface. While steel will have a light gray, closer to white, color and glossy shine.

If you look closely at the surface defects, cast iron will have characteristic hemispherical small grains. Unfortunately, this method is not an accurate determination of the material, since it is possible to determine “by eye” whether it is cast iron or not only if the alloy (in this case cast iron) was poured into the mold at a low temperature, was not further processed and was not coated no paints and varnishes.

It is the characteristic small hemispherical grains that indicate the pouring of the alloy at high temperatures.

The mechanical method can provide more information in determining cast iron. To do this, it is necessary to obtain alloy shavings. This can be done by drilling to a shallow depth in some area of the non-working part. For high-strength cast iron, the shavings will be characteristic - they will crumble, grinding into dust in the hands and leaving a mark on the fingers, similar to the lead of a simple pencil. Cast iron shavings are not able to wrap themselves in a twisted rope. This is due to one of the properties of cast iron - fragility.

If you try to cut a cast iron product with a grinder, then short sparks will fly from it, having a reddish tint on the star at the end of the track.

All of these options are valid for determining cast iron at home. However, they cannot give a 100% determination. To more accurately determine the alloy, spectral analysis, microscopic analysis, as well as weighing and volume determination are used.

Cast iron

Source: http://mining-prom.ru/rud/zhelez/svoystva-chuguna/

White cast iron: properties, application, structure and features

A distinctive feature is that cast iron contains more than 2% carbon in the form of cementite, which is not found in other metals.

A prominent representative of such an alloy is white cast iron, which is used in mechanical engineering for the manufacture of parts, in industry and in everyday life.

Appearance

The alloy has a white color when fractured and a characteristic metallic luster. The structure of white cast iron is fine-grained.

Properties

In comparison with other metals, iron-carbon alloy has the following characteristics and properties:

high fragility;
increased hardness;
high resistivity;
low casting properties;
low machinability;
good heat resistance;
high shrinkage (up to 2%) and poor filling of molds;
low impact resistance;
high wear resistance.

The metal mass has great corrosion resistance in hydrochloric or nitric acid. If there are free carbides in the structure, then corrosion will occur when cast iron is placed in sulfuric acid.

White cast irons, which contain a lower percentage of carbon, are considered more resistant to high temperatures. Due to the increased mechanical strength and toughness that appear when exposed to high temperatures, the formation of cracks in castings is minimized.

Compound

Iron-carbon alloy is considered a cheaper material compared to steel. White cast iron contains iron and carbon, which are in a chemically bonded state. Excess carbon, which is not present in the solid solution of iron, is contained in a combined state in the form of iron carbides (cementite), and in alloyed cast iron in the form of special carbides.

Kinds

Depending on the amount of carbon content in white cast iron is divided into the following types:

Hypoeutectic contains from 2.14% to 4.3% carbon and, after complete cooling, acquires the structure of pearlite, secondary cementite and ledeburite.
Eutectic contains 4.3% carbon and has a structure in the form of a light background of cementite, which is dotted with dark pearlite grains.
Hypereutectic has from 4.3% to 6.67% carbon in its composition.

Application

Based on the above properties, we can conclude that it makes no sense to practice thermal and mechanical treatment of white cast iron. The alloy found its main application only in the form of casting. Consequently, white cast iron obtains its best properties only if all casting conditions are met. This processing method is actively used if it is necessary to produce massive products that must have high surface hardness.

In addition, white cast iron is annealed, resulting in malleable cast iron, which is used for the production of thin-walled castings, for example:

automobile parts;
products for agriculture;
parts for tractors, combines, etc.

The alloy is also used for the manufacture of plates with a ribbed or smooth surface, and is also actively used for the production of steel and gray cast iron.

The use of white cast iron in agriculture as a structural metal is quite limited. Most often, iron-carbon alloy is used for the manufacture of parts for hydraulic machines, sand throwers and other mechanisms that can operate under conditions of increased abrasive wear.

Bleached cast irons

This alloy is considered a type of white cast iron. It is possible to achieve a chill of 12-30 mm by rapidly cooling the surface of the iron-carbon alloy. Material structure: the surface part is made of white, gray cast iron in the core. Wheels, balls for mills, and rolling rolls are made from this material, which are mounted in machines for processing sheet metal.

Alloying elements of the alloy

Specially introduced alloying substances added to the composition of white cast iron can impart greater wear resistance and strength, corrosion resistance and heat resistance. Depending on the amount of added substances, the following types of cast iron are distinguished:

low alloy alloy (up to 2.5% excipients);
medium alloyed (from 2.5% to 10%);
highly alloyed (more than 10%).

Alloying elements can be added to the alloy:

chromium;
sulfur;
nickel;
copper;
molybdenum;
titanium;
vanadium,
silicon;
aluminum;
manganese.

Alloyed white cast iron has improved properties and is often used for casting turbines, blades, mills, parts for cement and conventional furnaces, pumping machine blades, etc. The iron-carbon alloy is processed in two furnaces, which allows the material to be brought to a certain chemical composition:

in a cupola;
in electric melting furnaces.

Castings made of white cast iron are annealed in furnaces to stabilize the required dimensions and relieve internal stress. The annealing temperature can increase to 850 degrees. The heating and cooling process must be done slowly.

The marking or designation of white cast iron with impurities begins with the letter H. Which alloying elements are contained in the alloy can be determined by the subsequent letters of the marking. The name may contain numbers that indicate the amount in percentage terms of additional substances that are contained in white cast iron. If the marking contains the designation Ш, this means that the alloy structure contains spherical graphite.

Types of annealing

To form white cast iron, industry uses rapid cooling of the alloy. Today, the following main types of carbon alloy annealing are actively used:

softening annealing is used primarily to increase the ferrite content of cast iron;
annealing to relieve internal stresses and minimize phase transformations;
graphitizing annealing, as a result of which it is possible to obtain malleable cast iron;
normalization at a temperature of 850-960 degrees, resulting in graphite and perlite, and also increases wear resistance and strength.

Additional information

Today it has been proven that there is no direct relationship between wear resistance and hardness of a carbon alloy. Only due to the structure, namely the arrangement of carbides and phosphides in the form of a regular network or in the form of uniform inclusions, increased wear resistance is achieved.

The strength of white cast iron is most strongly influenced by the amount of carbon, and the hardness depends on the carbides. The greatest strength and hardness are those cast irons that have a martensitic structure.

Source: https://FB.ru/article/365393/belyiy-chugun-svoystva-primenenie-struktura-i-osobennosti

Where is cast iron used?

23/01/2015

Advantages of cast iron

The obvious superiority of cast iron compared to other metals can be assessed based on its area of application, quality characteristics, casting properties and value. This is a truly leading alloy in its segment and has undeniable advantages:

1. Large-scale application.
2.Availability and low price.
3.Excellent casting properties.
4.Highest strength and hardness.
5.Good malleability.
6.Durability.