Is cast iron magnetic - Metals and their processing

What cookware is suitable for induction cookers?

Aesthetics in kitchen design are as important as its functionality. Therefore, more and more housewives are choosing induction cookers, which have many advantages - ease of maintenance, minimalist design, speed of cooking.

Even while planning the purchase of such household appliances, the housewife wonders what kind of cookware is suitable for induction cookers, and how to determine whether existing kitchen utensils can be placed on a new hob. Let's look at this issue that worries many.

How to distinguish cookware for induction cookers?

If you are going to buy new cookware, you should know that there is a special marking for cookware for induction cookers. Almost all modern manufacturers of quality goods put this mark.

The icon on the cookware for induction cookers is located on the bottom on the outside. It is made in the form of a spiral of 4-5 turns with or without the inscription Induction. This spiral symbolizes electromagnetic radiation, which is called induction. In physics, induction currents are also depicted in the form of such a sign.

Many people are concerned about the question of whether it is possible to use cookware for an induction cooker on other types of stoves, whether it will spoil, and whether it will work at all.

If you look closely at the markings, next to the induction icon you can find others that indicate the possibility of using such cookware on a gas and electric stove, which makes induction cookware universal.

Choosing cookware for induction cookers does not always require a large investment of money. Not everyone knows that in the cabinet where all kinds of frying pans, saucepans and ladle are stored there will certainly be dishes that can also be placed on the induction surface, even if there is no corresponding icon on it.

Are cast iron cookware suitable for induction cookers?

Grandma's old cast iron frying pan makes the best pancakes, unlike modern tefals. Do we really have to push it into the far corner and change it to a special one with a badge?

Of course not, since even though there is no corresponding marking on cast iron cookware (frying pan, duck pot or cauldron), it is suitable for use on a modern induction cooker. The point is that induction cookware must have ferromagnetic properties, in other words, attract a magnet. And cast iron magnetizes just fine.

Using enamel and stainless steel cookware

But what about the different-sized enamel saucepans, many of which have been in our kitchens since the times of the Soviet Union? The same law applies to them as for cast iron - you need to try such dishes with a magnet. If it sticks, then the pan can continue to perform its direct functions and the enamel layer is not a hindrance to this.

The main requirement for using old enamel cookware, or any other cookware, is a flat bottom, without grooves. After all, often the bottom of pans has a raised platform in the middle, and this will make heating difficult and the use of such dishes will simply not be effective. In addition, cookware with an uneven bottom that does not fully adhere to the induction surface makes a buzzing sound when standing on the stove.

Stainless steel cookware is most often suitable for an induction surface, but it is still worth checking it with a magnet, since some models of pans may have a bottom made of a different, non-magnetic alloy.

What cookware is not suitable for induction cookers?

Ceramic and glass dishes are not suitable for an induction cooker, since the device simply does not recognize them, because it only reacts to metal. Therefore, this type of cookware should be used for the microwave and oven.

Aluminum and copper cookware are not suitable for induction, because they are not magnetic at all. But if you really want to use, for example, a copper basin for making jam, you should put a circle of ordinary metal under it so that such a basin “works.”

Induction cookware size

As a rule, there are delineated zones on the stove that you should focus on when installing cookware. The saucepan and frying pan may be slightly larger than this circle and protrude beyond it - the cooking process will not change. But a small pot or ladle, the size of which is less than 12 cm, will not be recognized as a stove, and therefore you should purchase dishes with a diameter larger than this size.

Source: https://womanadvice.ru/kakaya-posuda-podhodit-dlya-indukcionnyh-plit

What is the visual difference between cast iron and steel?

An uninformed person believes that the main structural material of modern times is iron. Anyone who understands it knows that the word “iron” means iron-carbon alloys - steel and cast iron.

It would seem that these are two completely different materials and they are very easy to distinguish. However, given the wide range of their types and brands, the fine line of difference in the chemical composition of some of them is difficult to determine.

It is important to have additional skills in order to know the answer to the question: what is the difference between cast iron and steel?

Cast iron

An alloy containing iron, carbon in the amount of 2.14-6.67, sulfur, phosphorus, manganese, silicon and other additives is called cast iron. The history of smelting began in the Iron Age. An important structural material, the basis of metallurgy and all steelmaking.

Characteristics:

Rough, matte gray in color.
Melting at 1000-1600˚С depending on the composition (for industrial ones on average - 1000-1200˚С, white and pig iron melt at higher temperatures).
Density: 7200-7600 kg/m3.
Specific heat capacity: 540 J/(kg˚C).
High hardness: 400-650HB.
Low ductility, very crumbles when exposed to pressure; The highest values of relative elongation have ductile high-strength cast iron δ=6-12%.
Low strength: 100-200 MPa, for malleable it reaches 300-370 MPa, for some brands of high-strength – 600-800 MPa.
It is modeled using heat treatment, but rarely and with great care, since it is characterized by a cracking process.
It is alloyed with the help of auxiliary chemical elements, but a significant degree of alloying further complicates the processing processes.
It is characterized by satisfactory weldability, good machinability, and excellent casting properties. Cannot be forged or stamped.
Good wear resistance and corrosion resistance.

Cast iron is a material for body parts, blocks, and machine components made by casting. It is the main charge component for steel smelting.

Steel

An iron-carbon alloy containing carbon in an amount of not more than 2.14% and iron - not less than 45% is called steel. Its main characteristics:

Smooth, has a silvery color with a characteristic reflection.
Melting within 1450˚С.
Density ranges from 7700 to 7900 kg/m3.
Heat capacity at room temperature: 462 J/(kg˚C).
Low hardness, on average 120-250 HB.
Excellent ductility: the relative elongation coefficient δ for different brands ranges from 5-35%, for most – δ≥20-40%.
Average values of tensile strength for structural materials are 300-450 MPa; for especially strong alloyed ones – 600-800 MPa.
It lends itself well to correction of properties using thermal and chemical-thermal treatment.
It is actively doped with various chemical elements in order to change its properties and purpose.
Qualitatively high indicators of weldability, machinability and cutting.
Characterized by low corrosion resistance.

Steel is the main structural alloy in modern metallurgy, mechanical engineering, instrument making and technology.

Determining origin by type of part

Having examined the detailed characteristics of these alloys, you can confidently use the knowledge of how cast iron differs from steel. Having a metal object in front of you, doubting its origin, it is rational to immediately remember the main distinctive technological properties. So, cast iron is a casting material. It is used to produce simple dishes, massive pipes, housings of machine tools, engines, and large objects of simple configuration.

Parts of all sizes and complexity are made from steel, as forging, stamping, drawing, rolling and other methods of metal forming are used for this purpose. Thus, if there is a question about the origin of the reinforcement, there can be no doubt - it is steel. If you are interested in the origin of a massive cauldron, it is cast iron.

If you need to find out what the engine housing or crankshaft is made of, you should resort to other recognition options, since both options are possible.

Color features and fragility analysis

In order to know how to distinguish cast iron from steel by eye, you need to remember the main visual differences. Cast iron is characterized by a matte gray color and a rougher external texture. Steel is characterized by its special silvery shiny hue and minimal roughness.

Also important knowledge on how to distinguish cast iron from steel visually is information about the ductility of these materials.

If the workpieces or metal objects being examined do not have serious value, you can test them for strength and ductility by applying impact force. Brittle cast iron will crumble into pieces, while steel will only deform.

With more serious crushing loads, cast iron crumbs will turn out to be of small, varied shapes, and pieces of steel will be large, with the correct configuration.

Cut and drill

How to distinguish cast iron from steel at home? It is necessary to obtain fine dust or shavings from it. Since steel has high ductility, its chips also have a tortuous character. Cast iron crumbles, and when drilling, small chips are formed along with dust.

To obtain dust, you can use a file or rasp and slightly sharpen the edge of the part of interest. Examine the resulting fine shavings on your hand or a white sheet of paper. Cast iron contains large amounts of carbon in the form of graphite inclusions. Therefore, when rubbing its dust, a black graphite “trace” remains. In steels, carbon is in a bound state, so mechanical influence on dust does not give any visible results.

Heat and sparkle

How to distinguish cast iron from steel? You need to operate with the necessary equipment and a little patience.

In the first case, you can resort to heating, for example, using a blowtorch, initially wearing special protective clothing and following safety rules at work. The temperature must be increased before the metal begins to melt.

It has already been said that the melting point of cast iron is higher than that of steel. However, this applies mainly to white and pig iron. Regarding all industrial grades, they contain carbon in an amount of no more than 4.3% and melt at 1000-1200˚C.

Thus, it can be melted much faster.

An educational method for obtaining information about how cast iron differs from steel is to use an experimental sample on a grinding machine or under a sharp wheel of a grinding machine. The analysis is carried out according to the characteristics of the sparks. Cast iron is characterized by dim red sparks, while steel is characterized by bright, blinding short rays with a white-yellow tint.

What does it sound like

An interesting feature is how to distinguish cast iron from steel by sound. The two alloys sound different. It is not at all necessary to produce musical accompaniment using existing experimental facilities. But it is necessary to have both samples or have an experienced ear in this matter. Steel is characterized by a higher density, which is reflected in its sound. When you hit it with a metal object, the sound is much louder than in the same situation with cast iron.

In order to know how cast iron differs from steel, you need to have a little knowledge about these materials and some experience. After all, an experienced professional in the field of forging, grinding, milling, drilling, turning, heat treatment or welding, a metallurgist or technician can easily distinguish them from each other, assessing them only visually or by touch.

Source: https://FB.ru/article/272426/chugun-ot-stali-chem-otlichaetsya-vizualno

Is cast iron magnetic or not: how to determine by the properties of the metal?

Cast iron is a metal that is used in industry for the manufacture of household products. The composition of the metal includes various elements, the presence of which will affect the ability of cast iron to magnetize.

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General information

It is an alloy of iron and carbon, which must contain at least 2% in the alloy.

Has several varieties:

By its nature, iron is a very soft but strong material; in order to cope with its softness and give strength, carbon is added to the alloy. Malleable cast iron - this name does not mean that the metal can be forged, but indicates its ductility.

White cast iron is white when broken. It is heavy, durable and not susceptible to wet corrosion. It has several varieties and is used for the manufacture of malleable materials.

Gray cast iron contains impurities; this epithet refers to an alloy of iron, carbon and silicon. Most of the carbon in the master alloy is in the form of graphite. At the break it is gray in color.

It is worth paying attention to high-strength cast iron, which contains spheroidal graphite. It does not weaken the metal mesh as much and is not considered a stress raiser.

In terms of production volumes, Russia is one of the top three, second only to China and Japan.

Carbon in the alloy is contained in the form:

Graphite is a mineral in the form of nuggets, considered a modification of carbon. You can see this element if you have a pencil in the house, where the graphite is in the form of a rod. Graphite has been known for a long time, its use depends on the industry: it is relatively soft, in ancient times it was used in the manufacture of clay dishes. In an alloy with iron, it is a source of carbon, and changes with increasing temperature, becoming harder but more brittle.

In chemistry, a carbon atom that has a bond with three other atoms. When added to iron, it affects its properties, increasing the hardness of the alloy.

Cementite, or iron cardite, is brittle, ductile and weakly magnetic. Formed in a material that contains iron even with a small amount of carbon. It is considered a phase and structural component of the alloy.

As a percentage, it does not exceed 2.14%. The melting point is from 1150 to 1200 °C, 300 °C lower than that of iron.

It is worth noting that cast iron is susceptible to dry corrosion. Compared to steel, it may seem that it has a certain advantage in anti-corrosion properties, but this is not the case. Steel and cast iron are equally susceptible to corrosion.

Main characteristics

The properties of cast iron can be classified according to the following points:

Chemical.
Thermal.
Technological.
Hydrodynamic.

The chemical characteristics of the metal are its tendency to corrode. It depends on the composition of the alloy and the elements that are included in it, as well as on environmental factors. Elements in the composition of the alloy can either reduce the susceptibility of the metal to corrosion or increase it, it all depends on their effect on the structure of the metal.

The thermal conductivity of iron decreases due to an increase in impurities in its composition. The thermal conductivity of the alloy changes due to the degree of its graphitization.

Fluidity is classified as a technological property; its degree is determined in various ways. This property increases with decreasing viscosity.

The viscosity of the metal decreases with an increase in the content of manganese in the composition, as well as with a decrease in the amount of sulfur and other non-metallic inclusions in the alloy. Viscosity also depends on temperature. It is proportional to the absolute temperature and the experience of contact with it.

There are also magnetic properties of cast iron, which mainly depend on the structure of the metal. They are divided into primary and secondary.

Primary characteristics include:

magnetic transformation temperature;
saturation;
induction;
permeability in strong fields.

These characteristics do not depend on the shape and distribution, but depend on the number and properties of the phenomenal phases.

Secondary characteristics include:

permeability in weak and medium fields;
coercive force;
induction;
saturation;
residual magnetism.

Secondary properties are determined mainly by the shape and distribution of structural components.

There is paramagnetic or non-magnetic cast iron. This is a material that is used when it is necessary to reduce the magnetic properties of a metal, and it is not possible to replace it with an alloy of non-ferrous metals.

More often than others, carbon and iron are diluted:

Nickel.
Manganese.
Copper and aluminum.

Soft magnetic material has magnetic properties. Ferrite and cementite are responsible for them. The magnetic characteristics of the metal and the degree of their expression depend on the amount of cementite.

The same amount of graphite in an alloy can determine its different metallic properties. Thus, not all types of cast iron have magnetic properties, but only malleable and high-strength ones.

But gray cast iron with the same matrix does not have similar properties. Therefore, it is classified as a paramagnetic material.

A reduction in the amount of perlite, which is often used in metallurgy in the manufacture of parts, also affects the material in a similar way. Tempering after hardening can improve the magnetic components of the metal.

A metal may or may not have magnetic properties, and the reason is not carbon. Iron is magnetic, and all alloys that contain this element have similar characteristics.

But we should not forget that the alloy is influenced not only by iron, but also by carbon, as well as other elements: nickel, copper, manganese, etc. Due to its properties, the material has various applications.

Thus, cast iron is either magnetic or not, it all depends on the alloy, as well as on the presence of cementite in its composition.

Source: https://vseprokamni.ru/metal/chugun-magnititsya-ili-net.html

Why isn't cast iron magnetic? — Metals, equipment, instructions

Cast iron is a combination of carbon (C) and iron (Fe), which has a number of characteristics and certain similarities to steel. Steel also contains carbon and iron. When analyzing the characteristics of metal as a chemical element, it is worth paying attention to whether cast iron is magnetic or not? What influences its characteristics and what do they depend on?

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Source: https://spb-metalloobrabotka.com/pochemu-chugun-ne-magnititsya/

How to distinguish cast iron from steel at home

The development of industry and the creation of synthetic materials cannot detract from the advantages and benefits of traditional materials. These include cast iron and steel. These are some of the oldest familiar alloys to human civilization.

The technology of repair and design work often includes various types of processing. It could be:

mechanical
chemical
thermal
electrolytic
plasma and other types of processing.

Despite the fact that cast iron and steel differ from each other by a tiny difference in carbon content, the methods and methods of influencing factors on these alloys differ and require different ways of the same method to influence the shape and structure of the metal.

Factors affecting the processing of steel and cast iron

In order not to waste money and resources, it is very important to know how to identify cast iron or steel.

Selecting a welding electrode
drill sharpening angle
drilling and milling mode

These are not all the factors that can complicate the life and work of a person who incorrectly determines the type of metal. Reducing mechanical, strength and violating guaranteed repair intervals is a much greater evil that can damage production and the budget in the event of an error.

Visual definition

How can you distinguish cast iron from steel visually without resorting to destructive testing methods? If there is a question about welding a cracked section of a part or even a piece that has fallen off, then it is possible to examine the breakdown or structure of the crack. The metal on a scrapped cast iron part will most likely be dark gray in color with a matte surface. Under the same conditions, the steel fracture will have a light gray, almost white color, with a glossy sheen.

The nature of cracks on the surface of high-carbon alloys is similar to a crack on pottery; low-carbon alloys are prone to plastic deformation and for this reason the crack has the shape of a rupture of plastic material.

Based on surface defects, only cast iron can be identified, which was poured into the mold at a low temperature, was not processed later, and a decorative paint layer was not applied. On such a product, hemispherical small grains are visible, formed due to non-shedding due to low temperature.

Don't forget about the correct visual method for identifying material. Soviet, modern and foreign GOSTs require the presence of material markings on all cast products. On domestic casting, the icons MF, HF, KCH - this means cast iron. L45, 45HL, 110G2S - indicates the use of steel casting for this element.

Mechanical determination by drilling

High-strength cast iron with nodular graphite is very similar in quality and visually to steel products. Testing a product by tearing it using a tensile testing machine is not entirely justified or reasonable.

To do this, you can select a non-working, inconspicuous area on the product and drill it not to the full depth with a drill of minimum diameter. The structure of cast iron is such that the chips are not able to form into a twisted loach. Graphite inclusions, even if they are not visible, crumble the chips at the stage of their formation.

Such shavings grind into dust in your hands and leave a black mark on your hands, like the lead of a simple pencil.

Steel shavings are capable of forming a loach longer than the length of the drill itself, and do not crumble in your hands. At high speeds it has a tarnished color on the surface.

Mechanical determination by grinding

You can approach the issue of determining the material using a grinder (angle grinder). As in the previous method, we select a section that is not a friction plane, contact pad or other important design element. With the machine turned on, we come into contact with the surface under study and monitor the shape and color of the sparks.

In cast iron products this will be a short spark with a reddish tint on the sprocket at the end of the track.

In metal products, the sheaf of sparks will be relatively larger, the tracks will be longer, and the sparks will be dazzlingly white or yellow.

If there is uncertainty and uncertainty in the method and your assessment, then you can take a known material, for example, a cast iron cauldron in the corner of the garage and check what sparks fly when processed with a grinder. At the same time, we should not forget that a number of special-purpose steels, especially heat-resistant ones, produce a spark of minimal size, with a short track and cherry red color.

This material does not cover methods exotic for home use:

spectral analysis
microscopic analysis
weighing and volume determination.

But for home needs, the above methods are more than enough. Regardless of the method and method of determining the material, try to use diagrams, drawings and other information for your unit or product. The amount of information on the World Wide Web is off the charts and can reach the most remote corner of a workshop or garage.

Source: http://solidiron.ru/obrabotka-metalla/kak-otlichit-chugun-ot-stali-v-domashnikh-usloviyakh-bez-specialnykh-priborov.html

How to distinguish cast iron from metal - Metalist's Handbook

Among the metals produced in one technological process, some of the most common are steel and cast iron. Despite the fact that one is made as a result of alteration of the other, these metals differ significantly from each other, both in their composition and in their use in the economy.

How steel is made

Steel is an iron-carbon alloy in which the carbon content does not exceed 3.4 percent . The usual figure is in the range of 0.1-2.14% .

It reduces the plastic characteristics of steel, while making it harder and stronger. Alloyed and highly alloyed contain more than 45% iron.

The elasticity of steel determines its demand for the creation of engineering products, primarily power springs and springs, shock absorbers, suspensions, braces and other elastic parts.

Regardless of the forms and operating conditions of the elastic parts of machines, mechanisms and devices, they have a common remarkable quality. It lies in the fact that, despite large shock, periodic and static loads, they have no residual deformation.

Steels are classified according to their purpose, chemical composition, structure and quality. There are many categories of appointments, including the following:

Instrumental.
Structural.
Stainless.
Heat resistant.
Resistant to ultra-low temperatures.

Steels can vary in their carbon content, from low-carbon, in which it is up to 0.25%, to high-carbon with 0.6-2%. Alloyed ones can contain from 4 to 11 or more percent of the corresponding additives. Depending on the content of various impurities, they are classified into steels with ordinary qualities, high-quality and those with especially high qualities.

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In its production, the main thing is to reduce to the required level the content of sulfur and phosphorus, which make the metal brittle and brittle. In this case, different methods are used for carbon oxidation, which can be open-hearth, converter and electrothermal.

The open-hearth method requires a lot of thermal energy, which is released when gas or fuel oil is burned. Arc or induction furnaces are heated using electricity. The converter version does not require an external heat source.

Here, molten pig iron is usually separated from impurities by blowing oxygen through it.

The raw materials for steel production are metal, pig iron, and additives that form slag and provide steel alloying. The smelting process itself can be carried out in different ways. It happens that it begins in an open-hearth furnace and ends in an electric one.

Or, in order to obtain steel that is resistant to corrosion, after melting in an electric furnace, it is poured into a converter. In it, it is purged with oxygen and argon to minimize carbon content. Steel melts at a temperature of 1450–1520 °C .

How to get cast iron

An alloy of iron and carbon can also be called cast iron. However, unlike steel, it must contain at least 2.14% carbon, which gives this very hard material high brittleness. At the same time, it becomes less ductile and viscous. Depending on the content of cementite and graphite in it, cast iron can be called white, gray, malleable and high-strength.

The first contains 4.3-6.67% carbon . It is light gray at the break. It is used primarily to produce malleable cast iron using annealing technology. Cast iron is called gray because of the gray color of its fracture due to the presence of graphite in lamellar form and the presence of silicon.

As a result of prolonged annealing of white cast iron, malleable cast iron is obtained. It has increased ductility and toughness, impact resistance and greater strength. Complex parts for machines and mechanisms are made from it.

It is marked with the letters “K” and “H”, after which numbers are placed indicating the tensile strength and relative elongation.

High-strength cast iron is distinguished by the presence of spheroidal graphite, which prevents stress concentration and weakening of the metal base. A laser is used to strengthen it, which makes it possible to obtain critical machine parts of increased strength. For industrial needs, there are various classifications of pig iron, anti-friction, alloy and graphite-containing cast iron. Its melting point is between 1,150 and 1,200 °C.

Cast iron has proven itself to be a versatile, inexpensive and durable material . Complex and massive parts of machines and mechanisms, as well as unique artistic products are made from it. Cast iron decorations and monuments decorate many cities around the world. Fences of ancient buildings, steps in them, and water and sewer pipes skillfully made from it have served people for centuries.

Cast iron hatches cover communication wells on the streets of many settlements. Bathtubs, sinks and sinks, heating radiators made of this material are reliable and durable. Crankshafts and cylinder blocks of internal combustion engines, brake discs and other automobile parts are cast from cast iron.

Typically, cast iron parts undergo additional machining after casting.

What makes them different

Steel and cast iron are materials widely used in industry, transport and construction. Outwardly they are very similar.

However, there are these main differences between them:

Steel is the final product of steelmaking, and cast iron is the raw material for it.
Steel has higher strength and hardness than brittle cast iron.
It contains much less carbon than cast iron.
Steel is heavier than cast iron and has a higher melting point.
Steel can be processed by cutting, rolling, forging, etc.; cast iron products are mainly cast.
Cast iron products are porous and have a thermal conductivity significantly lower than steel
New steel parts have a silver shine, cast iron matte and black.
To give steel special properties, it can be hardened; this is not done with cast iron.

Source: https://ssk2121.com/kak-otlichit-chugun-ot-metalla/

Characteristics and magnetic properties of cast iron. Is cast iron magnetic?

Miscellaneous Is cast iron magnetic?

Methods for determining cast iron

You can identify cast iron by the density of the product. Weigh the object and then determine how much water it displaces. This way you will calculate its density and draw a conclusion about the material.

The fact is that the density of the main steel grades lies in the range of 7.7 - 7.9 grams/cm3, while the density of the most common gray cast iron does not exceed 7.2 grams/cm3. But this method is unreliable, since there is also white cast iron, the density of which varies between 7.6 and 7.8 grams/cm3.

Therefore, it can only be used if you are firmly convinced that the product is made of either steel or gray cast iron.

You can use a magnet. It sticks to cast iron worse than to steel. But this method cannot be called accurate, since some types of alloy steels with a high nickel content almost do not attract a magnet.

Therefore, it is more reliable to use one of the following methods: determine cast iron using the type of sawdust or shavings formed, as well as using a grinding machine. Take a finely cut file and run it over the surface of the product several times. Try to collect the tiny sawdust that forms on a sheet of paper. Fold the paper in half and rub vigorously. If it is cast iron, then the paper will be noticeably stained; if it is steel, there will be practically no marks left.

You can also drill the product a little with a thin drill (of course, not from the front side, but in a place that is not obvious). This produces a small amount of chips.

By its appearance and properties, you can accurately determine what material the part is made of. If it is cast iron, the shavings will literally crumble in your fingers, turning into dust.

If it's steel, the shavings will look like a coiled spring and may even scratch your fingers if you try to break them.

Finally, you can judge a material by the size, shape and color of the sparks produced when a sander is passed along the edge of the product. The higher the carbon content, the brighter and stronger the sheaf of light yellow sparks will be. And the carbon content in cast iron is much higher than in steel.

If in doubt, it is better to use pieces of cast iron and steel as standards and compare the shape and properties of sawdust (shavings), as well as the type of sparks produced, with what is obtained when processing these samples.

There is China and China. At IKEA, all the stainless steel is made in China, but the holders of the brand (the Swedes, and now, it seems, the Dutch) tightly control the production. As a result, it seems to me that the price/quality ratio of very unassuming IKEA pots and pans is one of the best on our market. Everything works on an induction panel, if stated.

Most of the world's BRAND electronics are made in China. As for other “household” garbage, I can name some knife manufacturers.

It’s worse when the brand itself is Chinese, but even here there is rapid progress: there are things (for example, in electronics, in the production of buses) that the Chinese, under state control, have begun to do very well.

But when our business sharks come into play, creating “German” brands and sticking Western-style labels on the products of Chinese unknown and uncontrolled artisans, then hold on.

I heard that during the times of perestroika cooperatives in Odessa, the highest chic was considered not to be counterfeiting sneakers under the branded “Addidas”, but to make them look like a Chinese counterfeit “Addidas”. This style has been preserved by all those who rise from their knees - everywhere. Trash and cattle, robbing their own.

Hospadi! When will this notorious “magnet” disappear from culinary communities? The classic “food-grade stainless steel” - steel “18/10” - is not attracted by any “permanent magnets”, but it is perfectly suitable for induction cookers.

Members

1967 messages

City: Ukraine
Name: Sergey Savelievich

How to distinguish cast iron from steel.

Look carefully at the crankshaft; cast iron is cast; steel is usually forged from a whole piece of steel. It can be almost unmistakably determined by its appearance. By the way, what engine does the crankshaft come from? And once again, by the way, the vast majority of crankshafts are cast iron. Obviously casting is cheaper and easier than forging.

#16 Sergey19

Source: https://infwar.ru/raznoe/magnititsya-li-chugun.html

Differences between cast iron and steel

18.01.2018 18:12

Steel and cast iron are some of the most popular types of casting materials used in industry. They are quite similar in their properties; you can understand the difference between steel and cast iron in different ways. Some of the methods can only be used in a factory environment using high-precision equipment, while others are suitable for use at home.

The main difference between cast iron and steel is the composition of the metals. Steel is an alloy of iron (45%) with carbon (no more than 2%) and alloying impurities, which can be substances such as nickel, molybdenum or others.

This metal is characterized by high strength, ductility, and ease of processing. Cast iron also contains iron and carbon, but the latter should be 2% or more.

Alloying additives are usually silicon, phosphorus, manganese or other components.

Differences in physicochemical characteristics

The main difference in the qualities of these metals is as follows:

The hardness of steel is higher than that of cast iron.
The weight of steel products is less, and the material melts more easily.
Certain types of processing are available only for steel workpieces (forging, welding), while cast iron products are manufactured only by casting.
The thermal conductivity of cast iron products is lower than that of their steel counterparts.
Cast iron does not require mandatory hardening.

Is it possible to distinguish cast iron from steel visually?

If we are talking about fragments or workpieces, the processing of which will not cause harm, you can look at the visual differences between the metals. When a cast iron product is scrapped, a dark gray matte tint appears; the steel surface is lighter and has a glossy texture.

The appearance depends on the content of carbon components; they can be distinguished by the type of cracks: on high-carbon steel surfaces they look like a defect in the form of a split; on a product made of a low-carbon iron alloy, the cracks look like a plastic-type rupture.

To the question of whether it is possible to distinguish finished products by shade or texture, one can give a definite answer: objects made of steel are lighter and almost always have a glossy tint, products made of cast iron are dark and matte.

How to distinguish cast iron from steel?

To distinguish these metals from each other, you can use the following methods:

Drilling. To do this, you will need to take a nozzle with a small diameter and, having selected a flat area on the workpiece, drill a small hole. If, when processing a material, thin chips are formed, which are formed into a twisted strip longer than the drill used, have tarnish colors along the entire length and bend well enough, the workpiece is made of steel. The cast iron alloy is less ductile, it practically does not form a loach, and the shavings crumble from the slightest mechanical impact: they are easy to grind to a powder state, since the material is more fragile;
Grinding. For this, an angle grinder is used; for processing, select an area that is not affected by frictional forces, contact with other metal surfaces or parts, otherwise, after grinding, the product may be unsuitable for further use. During the processing process, it is necessary to monitor the color of the spark and its shape. If the alloy is cast iron, the spark will be short, the sprocket will have a reddish tone, and if the part is made of steel, more sparks will fly out, they will have an increased size and an oblong shape. The sparks themselves are yellow or white. The exception is steel alloys with a high carbon content, which produce a short, purple spark with a shortened track and a small sprocket.

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Mechanical impact methods can be used in everyday conditions, when you need to determine whether the material in front of you is cast iron or steel, without the use of special equipment.

The laboratory can use modern technology, with the help of which spectral or microscopic analysis of the properties of metals is carried out.

These methods provide highly accurate results, but are used primarily for industrial purposes, in production and in the scientific and technical industry due to the complexity and high cost of the equipment.

Source: http://metallomcity.ru/stati-o-metallolome/otlichiya-chuguna-ot-stali

Characteristics and magnetic properties of cast iron. Is a cast iron frying pan magnetic?

Is cast iron magnetic? - studvesna73.ru

Cast iron and steel - two types of iron-carbon compounds - are widely used in a wide variety of industries. But sometimes it becomes necessary to distinguish cast iron from steel, for example, during repairs, because these alloys have different properties and, accordingly, require different handling.

The bottom is like a sandwich and is magnetic: what is the advantage of cookware for induction cookers

You got an induction cooker after hearing a lot of positive reviews. But while cooking, the stove begins to make noise, crackling and even howling.

The whole reason for these troubles lies in the incorrectly selected cookware for the induction cooker. Now we will tell you how to choose the right kitchen utensils for cooking on an induction stove.

Properties

So, this type of cookware should have:

Ferromagnetic (be magnetized to a magnet). The tile coil works on such a principle that non-magnetic alloys will not be able to work with it for heating.

By the way, if only one bottom is magnetic, but the rest is not, such dishes are also suitable.

Thick bottom. When the stove is in operation, the thin bottom is deformed, as a result there will be no tight fit to the coil, resulting in noise, rumble and possible cessation of heating during cooking.

To avoid such embarrassment, the thickness of the bottom should be at least one centimeter.

Cookware for an induction cooker must have a diameter no less than that specified in the cooker's passport, and vary depending on the brand of the product. Due to its design feature, the tile coil will not respond to kitchen utensils of smaller diameter.

How to choose?

The listed requirements are basic for all kitchen utensils designed to work with induction hobs.

But many, having started to study the offers on the market, do not know how to choose high-quality induction cookware. We will try to help with this.

So, the material for making this utensil can be:

cast iron;
stainless steel;
composite

Cast iron is a time-tested material. It is good for stewing meat and vegetables. But it is heavy, susceptible to corrosion, fragile and not presentable.

Food in stainless steel cookware is not subject to oxidation. The dishes are not heavy, they look presentable and beautiful.

The only negative: in cheap products, the bottom is not thick enough, and the inner surface is not protected by a non-stick coating.

The bottom of composite cookware is made of steel, and the walls are made of another material.

Bottom type

Now a few words about the type of bottom of the product. It can be in the form of a simple “pancake” made of steel or cast iron, or multilayer.

Typically, a multi-layer bottom consists of a steel first layer, an aluminum second layer and a non-stick third layer. This kind of bottom is the most practical. Steel ensures the operation of the tiles, aluminum easily accumulates heat and transfers it to products, and a special coating will eliminate spoiled dishes.

Old cookware (even enamel) can also be suitable for cooking on this type of kitchen tile.

Check the bottom of each pot and pan with a magnet: if it is magnetic, the dishes are suitable for use. But remember, not all old cookware has the required bottom thickness; in most cases, they do not have a non-stick coating.

Knowing the basic requirements for this type of pots and pans, you can not waste your time running around the city, but buy cookware for an induction cooker through an online store.

Reviews

Is appropriate cookware really necessary for an induction cooker? Maybe this is another marketing ploy? Let's listen to the reviews of housewives.

Maria, 23 years old:

- Don't buy cheap stuff! It is better to overpay, but buy a quality product. My husband and I bought a set of stainless steel cookware, but saved on the non-stick coating. The stove heats very well and quickly, but due to the lack of coating, dishes often burn. As they say, the miser pays twice. And the difference in price was insignificant.

Antonina, 43 years old:

– I agree with the review about cheap pots and pans. We bought a set of cheaper ones, although they had a non-stick coating. But during cooking, the stove periodically makes noise. It turned out that the bottom of this dish is only five millimeters, and when heated strongly, it “twists.”

Evgeniya, 29 years old:

– And we immediately bought an expensive set. My husband says that the dishes are made of different metals and have a bottom like a sandwich. Although it’s a little expensive, I can cook any dishes without any problems.

Source: https://moemchistim.com/kuhnya/dno-kak-u-sandvicha-i-magnititsya-v-chem-preimuschestvo-posudy-dlya-indukcionnyh-plit.html

What are the magnetic properties of cast iron

Here you can find background information on the topic of the magnetic properties of cast iron, for the following cast irons: white cast iron, gray cast iron, ductile cast iron, ductile cast iron, alloy cast iron

The magnetic properties of cast iron are a rather interesting practical topic, which has not yet been so well covered in publications on various sites. Therefore, we decided to dwell on this topic in a little more detail. In general, this article is a kind of subsection of a more general publication called: properties of cast iron.

Therefore, if you are interested in other properties of this metal, you can follow the link to the general article. It is useful to consider the properties of cast iron not in the style of academic research in metal science, but “from the angle” of practical application, projecting them onto certain specifics of production.

What is made from cast iron? Usually, in the broadest sense, either final, finished products or parts used in the form of structural elements are made from cast iron. Let's start from the manufacture of parts made of cast iron; in some of them, the magnetic properties of cast iron become extremely important.

In accordance with the requirements for parts, cast iron can be used as:

a) Ferromagnetic material. Ferromagnetic materials, cast iron in particular, are also called soft magnetic materials. Therefore, the term soft magnetic cast iron, which you can find in the literature, should not confuse you. We are talking about ferromagnetic cast iron, an unusual synonym is simply used, by the way, ferromagnetic material is soft magnetic.

b) Paramagnetic material. Sometimes you can find a slightly different spelling: steam magnetic cast iron or para-magnetic cast iron are the same thing. In old literature you can read a slightly different transcription: steam-magnetic cast iron. Today it is not customary to write like that. Paramagnetic cast irons are considered non-magnetic and are used where there is a need for cast iron parts not to have pronounced magnetic properties.

The magnetic properties of cast iron, to a greater extent than any of its other characteristics, depend on the structure of the metal, which determines the division of magnetic properties into primary, characteristic of cast iron, and secondary properties, due to differences in the structure of cast iron.

The primary ones include: magnetic induction, magnetic saturation, magnetic permeability in strong magnetic fields and magnetic transformation temperature. These primary properties of cast iron depend on the quantity and composition of ferromagnetic phases and do not depend on their shape and distribution in cast iron, that is, they do not depend on the structure of a certain grade of cast iron.

The secondary PROPERTIES of cast iron include the so-called hysteresis characteristics of cast iron: magnetic induction, magnetic saturation and permeability in weak and medium fields, coercive force and such a physical phenomenon as residual magnetism.

The secondary magnetic properties of cast iron depend very little on the composition of the phases and are determined mainly by the shape and distribution of structural components. That is, the secondary properties of cast iron depend primarily on the structure of the cast iron.

What determines the ferromagnetic properties of cast iron?

Naturally, the magnetic properties of cast iron are determined by some materials included in its composition that have pronounced, highly magnetic properties. The Metal Science Handbook determines that the main ferromagnetic components included in cast iron are ferrite and cementite. If necessary, you can see what data characterizes ferrite and cementite in cast iron in the table HERE.

As we can see from the table, cementite in the composition of cast iron is a more rigid magnetic component that determines its magnetic properties, therefore gray rather than white cast iron is always used as a soft magnetic material. It is in the composition of gray cast iron that we have a larger amount of cementite. And the magnetic properties of gray cast iron allow it to be used like ferromagnetic cast iron.

A process such as graphitization of cast iron leads to a sharp decrease in the coercive force and an intensive increase in the absolute maximum magnetic permeability. And the increase in magnetic permeability is higher, the more completely the carbides in cast iron decompose. In this case, the influence of graphite, like other non-magnetic phases, is nonlinear and also depends on the shape and size of graphite inclusions.

The same amount of graphite in cast iron can determine different magnetic properties of cast iron, depending on the grain size of graphite inclusions in the structure of cast iron. The most favorable in this regard is the globular form.

Therefore, malleable and high-strength cast iron are characterized by higher magnetic induction and magnetic permeability, lower coercivity than gray cast iron with the same matrix (see Table 10).

The magnetic properties of cast iron are similarly affected by the enlargement of eutectic and ferrite grains and a decrease in the amount of pearlite. What is used in practical metallurgy in the manufacture of cast iron parts. For example, tempering after hardening helps to improve the magnetically soft properties of cast iron and products made from it.

Non-magnetic (paramagnetic) cast irons of various grades are used in cases where it is necessary to minimize power losses, in products such as oil switch covers, transformer end boxes, pressure rings on electric machines, etc.

Non-magnetic cast iron is also used when minimal distortion of the magnetic field is necessary, for example: stands for magnets, etc. In the first case, along with low magnetic permeability, cast iron also requires other properties, in particular high electrical resistance.

As for high electrical resistance, cast iron will satisfy this requirement even more than alloys of non-ferrous metals, and the cost of parts made of cast iron is significantly lower, which determines the preference for this type of material.

In the second case, a particularly low magnetic permeability is required; here the magnetic properties of cast iron do not provide us with room for maneuver. That is why in a number of cases, despite the financial and commercial attractiveness of the technology, it is still not possible to replace non-ferrous alloys with austenitic cast irons for the second group of castings.

Magnetic properties of cast iron. Non-magnetic cast irons

Depending on the composition, austenitic non-magnetic cast irons are distinguished:

a) nickel cast irons of the niresist type with one or another amount of chromium in the cast iron.

b) nickel-manganese cast irons of the Nomag type with varying amounts of copper and aluminum in the cast iron, superior to the cast irons of the first group in non-magnetic properties, but inferior to them in heat resistance, heat resistance and corrosion resistance.

c) manganese cast irons with varying amounts of copper and aluminum in the cast iron. These are the cheapest types of cast iron, but they also have negative properties. These types of cast iron are characterized by low strength and physical properties. Which imposes certain restrictions when using them for the manufacture of many types of cast iron parts.

Source: http://4ypakabra.ru/kakie-magnitnyie-svoystva-chuguna/