What is heavier cast iron or steel

How to distinguish cast iron from steel, iron and aluminum at home

Cast iron is an alloy of iron with a sufficient carbon content (from 2.14 to 6.67%). The concentration of the added substance affects the ductility, ductility and hardness of the metal, so steel is made from an alloy of iron and less than 2.14% carbon. Cast iron alloy is very hard and brittle and difficult to cast and process with cutting tools. Therefore, it is quite simple to distinguish cast iron from steel by properties, appearance and characteristics.

The high carbon content gives the high-carbon iron alloy a dark, almost black color. You can visually distinguish cast iron from steel by the lack of shine. Also, spel is formed on its surface - large inclusions of lamellar graphite, which are visible to the naked eye at the fracture. They appear as a result of crystallization of high-carbon alloys.

Main characteristics

In addition to carbon, manganese, sulfur, phosphorus, silicon, molybdenum, etc. are added to the alloy. The carbon in it is in the form of graphite or cementite (iron carbide), and their quantity determines the type of metal. All types of alloy are characterized by high density - about 7200 kg / cubic meter. m.

Cast iron can be distinguished from other metals by its poor weldability. During the heating process, oxidation of silicon in the iron alloy occurs. Due to its higher melting point, silicon oxide makes the welding process more difficult, so permanent joints are difficult to form. At the same time, cast iron alloys have a relatively low melting point (from 1150 to 1200 °C, which is lower compared to steel and pure iron).

Types of alloys

Main varieties:

• white - a metal with a light gray hue that is difficult to process, but has high hardness;
• gray - a material with a high carbon content in the form of graphite, which has good casting properties, is easy to process and is suitable for the production of machine elements, beds, covers, pulleys and presses;
• malleable - metal obtained as a result of heat treatment of a white alloy with the formation of flake-like granite (in demand in automotive production, in the manufacture of agricultural machinery and spare parts for it);
• half - material for the production of wear-resistant friction parts;
• high-strength – an alloy with spherical graphite in the composition for the production of pipes and machine elements.

To understand how to distinguish cast iron, it is important to study the characteristic features and areas of application of its varieties.

Metals that are often confused

A high-carbon iron alloy is often confused with other metals used for the production of plumbing fixtures, fittings, shut-off valves, machine tool parts, and radiators. People think about how to identify cast iron when trying to hand over scrap metal to a collection point. Scrap of this metal is one of the cheapest, since it is difficult to process, fragile, and harmful impurities (phosphorus and sulfur) are difficult to remove from it.

Therefore, before traveling to the collection point, it is important to determine whether it is cast iron or steel. It is also often confused with pure iron, aluminum and silumin - an alloy of aluminum and silicon used for the production of frying pans, pots, mixers, taps, etc. You can distinguish cast iron from iron and other metals at home: by color, magnetic properties, strength and even the sound!

Differences from iron

Pure iron is a material that can only be seen in the laboratory. It practically does not occur in nature, and is also not applicable for mass production of spare parts, plumbing products and household items. You can determine whether the material in front of you is cast iron or cast iron by its appearance: iron has a light silver color, is very soft and ductile, and is also highly susceptible to corrosion.

It is important not to confuse iron and its derivative, steel. These concepts are not interchangeable. Steel is an alloy of iron, small amounts of carbon, manganese, silicon, sulfur and phosphorus. This iron-carbon alloy is elastic, deformable, and malleable. It can also be difficult to distinguish steel from cast iron by eye: a similar composition gives them similar shades, but completely different properties and characteristics. Steel is easier to process, stronger, and resistant to shock and mechanical stress.

How to distinguish cast iron from steel?

Steel is a high-strength material with a melting point of approximately 1300–1500 °C. From it they produce:

• plumbing tools (hammers, chisels, screwdrivers, scythes, saws, scissors, etc.);
• machine parts (pushers, gears);
• springs and leaf springs;
• blacksmith tools;
• products for stone and wood processing;
• pipes and radiators;
• surgical equipment;
• building materials;
• dishes, cutlery and household items.

It is widely believed that cast iron can be distinguished from steel using a magnet. The statement is partly true, since the magnetic properties of a metal depend on its composition. Ausetnitic and austenitic-ferritic alloys with a high content of chromium (up to 20%) and nickel (up to 15%) are not magnetic. The inclusion of titanium, molybdenum, and niobium also reduces the magnetic properties of the metal.

Differences between steel and cast iron

A high-carbon alloy is always magnetic, while steel depends on its composition. Cast iron is also determined by the color and condition of the surface: products made from it have a dark, almost matte black color, and when broken, the metal is dark gray. Also, cast iron objects are more massive and weigh more compared to their steel counterparts, although the density of steel is much higher - up to 7900 kg / cubic meter. m.

Steel is easier to process, so items made from it are produced by stamping. Weak, non-ductile cast iron is suitable for the manufacture of cast products. It does not withstand strong impacts and can crack, so a strong blow with a hammer will help to distinguish it. At the same time, it is porous and retains heat longer, and therefore another test option is strong heating. Cast iron products heat up slowly but evenly, and cool down for at least 10 minutes.

Differences from aluminum

A magnet can be used to distinguish cast iron not only from steel, but also from aluminum - a silvery-white light metal. This substance is paramagnetic, therefore it has external magnetic susceptibility (in the absence of an external magnetic field, the magnetic moments of atoms are non-zero).

The relative magnetic permeability of the metal is slightly greater than unity, and the magnetic field in it increases insignificantly. Accordingly, aluminum is magnetic, but very weakly. This is not visible visually, so it is generally accepted that it is not magnetic.

In addition to magnetic properties, metals have other differences: color, mass, density, hardness and flexibility. Therefore, you can distinguish them from each other in other ways.

How to distinguish aluminum from cast iron?

1 cubic meter of aluminum weighs 2,700 kg, and cast iron - more than 7,000 kg. The first is less dense, and therefore products made from it should be much lighter compared to cast iron. But it should be taken into account that aluminum is less durable, so objects made from it are made thick-walled, which affects the weight.

Aluminum products are lighter and have a slightly shiny surface. Under atmospheric conditions, the metal is immediately covered with a transparent, gas-permeable oxide film. Aluminum is smooth and even, while cast iron is dark, porous and rough. A significant difference between metals is hardness: aluminum is easy to bend, and impacts form dents on its surface. Cast iron cannot be bent: under heavy loads it will crack, but will not deform.

Features of the delivery of cast iron scrap

This type of ferrous scrap metal is the most in demand, and it is classified as metal waste. It is recycled, melted down in smelters, and even recycled into steel by reducing its carbon concentration. Most of the cast iron scrap is of industrial origin.

Outdated machines, equipment, and dismantled metal structures are sold for scrap metal. The cost of such scrap is relatively low, but due to the large mass, these items can fetch good money.

You can distinguish cast iron from aluminum, steel, and iron by color, weight, and even sound (cast iron products are the most resonant, so when struck they make loud, sharp sounds). But the most reliable way is to send a metal sample to our laboratory equipped with a spectrometer. We will accurately determine the composition of the alloy and offer the best price for scrap metal!

Source: https://blog.blizkolom.ru/kak-otlichit-chugun/

How to distinguish cast iron from steel? — Metals, equipment, instructions

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: https://spb-metalloobrabotka.com/kak-otlichit-chugun-ot-stali/

Where to install a check valve in a water supply system

> Construction

20.01.2020

For stable operation of the heating system and water supply, it is necessary to install a check valve on the water. This equipment is classified as shut-off valves; its task is to allow water flow in only one direction. This function makes it possible to widely use this device, especially for self-priming pumps and for the installation of autonomous water supply systems.

Sometimes a check valve performs protective functions against a variety of unscheduled malfunctions and expensive repairs in the event of a leak. In this article we will consider in detail the features of the selection and installation of this unsurpassed device, as well as the question of how they are used.

Design and principle of operation

Answering the question why a check valve is needed, it is worth saying that this device does not allow the water raised by the pump to return back to the well or well. Another advantage of using this valve is that you do not have to wait for the liquid to displace the air in the hose. If the hose has already been filled with water, the flow will begin immediately.

What elements does the water check valve device include:

• a collapsible metal body, which consists of two parts, each of which has a thread;
• metal or plastic shutter with gasket;
• a spring designed to support the bolt.

The operation of the valve is not complicated. The principle of operation of a water check valve for a pump is as follows: after water stops flowing from the pump into the pipeline or hose, the valve is pressed by a spring and is in the closed position. When sufficient water pressure appears in front of the valve to depress the spring, the valve opens, allowing water to flow into the pipeline.

When the pump is turned off, the water pressure drops, the valve is again pressed by the spring and becomes in the closed position. In addition to the spring, water pressure is created on the valve from the side of the pipeline, preventing it from opening. The most popular type of check valve is for domestic use.

Important: all valves operate on this principle, regardless of whether they are used with or without a pump in the pipeline.

Types of check valves

Check valves may differ from each other in the material from which they are made, dimensions, design and installation features. Let's try to sort and classify them according to the given distinctive features.

By type of locking element:

• lifting type - in a device of this type of design, the shutter moves up and down. When water flows from the pump, the valve assumes an open position; when the pressure in the pipeline drops, the valve closes again under the action of a spring;
• rotary type - the valve in a valve with such a device looks like a flap, which opens during the movement of water and, with the help of a return spring, closes again when the pump is turned off;
• ball type - in this type of valve, the valve looks like a ball blocking the passage. The ball is supported by a spring. When water pressure is applied, the ball rises and moves, allowing water to flow into the line;
• wafer type - can be double-leaf or disk. A butterfly valve has a valve consisting of two flaps that fold when water passes and close when there is no water. The disc type check valve in its design has a disc valve capable of moving along its own axis under the action of a spring attached to it.

Household water valves most often have a lift-type design, where the spring can be replaced. Since it is its failure that is the main cause of valve malfunction.

According to the material of manufacture:

• made of brass - a reliable material that is resistant to corrosion, which is quite durable and easy to maintain. It is considered an ideal material for household use;
• made of cast iron - a rather rarely used material due to its poor resistance to corrosion and gradual fouling by deposits. Valves made of cast iron are used on large diameter pipelines. Valves made of this material are not found in household use;
• made of stainless steel - valves made from this material have virtually no disadvantages. They are resistant to corrosion and aggressive substances, strong and durable. The only drawback, perhaps, is the high price, but the quality of the product corresponds to the price.

Most often, the components of a check valve are made of different materials. For example, the body can be made of brass or stainless steel, usually the shutter is made of plastic, and the spring is made of ordinary or stainless steel. Therefore, during the purchase, it is recommended to ask what materials the valve parts are made of.

Advice: for household needs, it is better to opt for a brass product due to their fairly long service life and relatively low price.

By mounting method:

• coupling fastenings. Most models of check valves are attached in this way. The fastening consists of two threaded transitions. Their diameter varies greatly, depending on the diameter of the pipeline;
• flange mountings. As the name suggests, attachment to the pipeline is carried out using flanges. Most often, this type of fastening is used on valves made of cast iron, which are used on large diameter pipelines;
• Wafer mounts. With this type of mounting, the valves are secured between two flanges, which are secured with bolts. Valves with this type of fastening are also mainly used on large-diameter pipelines.

• standard valves. Used on most pipelines;
• miniature products mounted inside water meter drains. Used in cases where there is not enough space on the pipeline to install a standard check valve;
• small valves mounted at the outlet of water meters;
• cast iron valves of large sizes, mounted on industrial or public pipelines.

Where is this device installed?

Installation of a check valve on water is done in the following places:

• at the outlet of a submersible pump located in a well or borehole. After the pump stops working, the water will not return;
• at the end of the suction pipe of a surface pump or pumping station lowered into the water. After the pump unit is turned off, water will remain in the pipe;
• at the outlet of the cold pipeline into the boiler. In this case, if there is no water in the cold pipeline, there will be no reverse outflow of water from the boiler;
• for different types of pipelines, especially when hot and cold pipelines are used simultaneously. Due to the pressure difference in the pipelines, hot water may be forced into a pipeline with cold water or, conversely, through a mixer. A valve mounted on each of the pipelines separately will prevent its backflow;
• in autonomous heating systems, when there are several separate circuits with different coolant pressures. In this case, a separate pump is installed for each circuit. If the pumps are of different power, it may happen that a more powerful device can push the coolant into the adjacent circuit, which supplies the unit with a lower power. This is completely unacceptable, which is why a check valve is a mandatory part in such a system;
• on water meters in order to prevent water movement in the opposite direction;
• in the sewer to prevent backflow of waste.

Correctly installing a check valve on water yourself is quite simple; to carry out this operation, you just need to have the right tool and have minimal plumbing skills.

How to choose a valve for your home pipeline

When purchasing a protective device for installation on a pipeline, you need to take into account several features, then the device will delight the owner with its technical features. We invite you to consider a few simple rules.

1. Before purchasing, carefully study the design of the connecting elements of the device. It is very important that the diameters of the pipeline and the check valve match. In current living conditions, most people prefer to use coupling options, since most plumbing systems are assembled using this connection method.
2. Analyze the principle of operation of a check valve. If you lack knowledge, consult the seller, or refer to the documentation if the product is branded. If any malfunctions or violations are identified, it is better to refuse the purchase.
3. If you need to purchase a ball, flange or wafer mechanism for a pump or other technical needs, be sure to compare their capabilities with the characteristics of the environment in which they will operate.
4. The material from which the structure is made must be selected based on the technical characteristics of the water supply system: plastic is suitable for polypropylene structures. If the check valve must be installed on a hot pipeline, the best option would be to choose a device made of durable metal, since most propylene structures are unstable to high temperatures.
5. Brass products are an ideal alternative to all fragile structures. Products made from this material are well protected from various temperature and mechanical deformations; moreover, most designs have a ball-type action.

Attention! All devices for protecting against water hammer in a pipeline must be purchased wisely, when choosing, taking into account a number of functional features, and not just selection rules.

Installation in the main line

Installation of a check valve for water in the main pipeline in the house is carried out after the pump (if available) and after the water meter. It should be noted that the installation principle largely depends on the type of design you choose.

1. For coupling metal options, you can use welding or threaded connections. Both options are quite reliable in fixation. Most experts do not note that these installations are highly reliable, but, nevertheless, they are very functional.
2. If you decide to install a wafer mechanism, a technology is provided for securing it in the pipeline between two plates. It is worth noting that the plates must be welded to the pipes separately; the same installation method is practiced for the pump, but all fastenings must be made strictly after the water meter.
3. A ball check valve is a type of flanged check valve that operates using a ball valve. Its fastening should only be carried out in suitable conditions; in addition, it is very important to observe the working device of the water check valve.

The main installation rule is to screw the valve in the correct direction. In order to facilitate this task, an arrow is applied to the body of the device, which shows the direction of water movement through the valve.

We looked at the purposes for which a water valve is needed, its operating principle, and examined the types and features of valves of this type. The operation of these devices can prevent emergency situations in heating and plumbing systems, and in addition, simplify the operation of pumping stations and water pumps. Such plumbing equipment is irreplaceable and is always in demand.

Source: https://otoplenie-doma54.ru/stroitelstvo/kak-ustanovit-obratnyj-klapan-na-vodu-osobennosti-i-vidy.html

What is heavier steel or cast iron

Cast ironPhases of iron-carbon alloysFerrite (solid interstitial solution of C in α-iron with a body-centered cubic lattice) Austenite (solid interstitial solution of C in γ-iron with a face-centered cubic lattice) Cementite (iron carbide; Fe3C metastable high-carbon phase) Graphite stable high-carbon phase Ledeburite (eutectic mixture of cementite and austenite crystals, which turns into pearlite upon cooling) Martensite (highly supersaturated solid solution of carbon in α-iron with a body-centered tetragonal lattice) Pearlite (eutectoid mixture consisting of thin alternating plates of ferrite and cementite) Sorbitol (dispersed perlite) Troostite (highly dispersed pearlite) Bainite (ustar: acicular troostite) - an ultrafine mixture of crystals of low-carbon martensite and iron carbides White cast iron (brittle, contains ledeburite and does not contain graphite) Gray cast iron (graphite in the form of plates) Ductile cast iron (graphite in flakes) High-strength cast iron (graphite in the form of spheroids)Half cast iron (contains both graphite and ledeburite)Cast iron - an alloy of iron with carbon (and other elements), in which the carbon content is at least 2.14% (the point of limiting solubility of carbon in austenite on the phase diagram), and alloys with a carbon content of less than 2.14% are called steel. Carbon imparts hardness to iron alloys, reducing ductility and toughness. Carbon in cast iron can be contained in the form of cementite and graphite. Depending on the shape of graphite and the amount of cementite, white, gray, malleable and high-strength cast irons are distinguished. Cast irons contain permanent impurities (Si, Mn, S, P), and in some cases also alloying elements (Cr, Ni, V, Al and others). As a rule, cast iron is brittle. Cast iron is usually smelted in blast furnaces. The melting point of cast iron is from 1150 to 1200 °C, that is, about 300 °C lower than that of pure iron.

Etymology [edit | edit code]

In Russian, the word cast iron is of Turkic origin, while in Turkic languages ​​the term is probably from kit. trad. 鑄, pinyin: zhù , pal.: zhu , literally: “to pour; cast (metal)" and whale. trad. 工, pinyin: gōng , pal.: gong , literally: “deed” [1]. This is due to the fact that cast iron was a low melting iron alloy. In Finnish, cast iron is denoted by the word Valurauta , which has two roots and is translated as cast iron ( rauta ).

History [edit | edit code]

The technology of cast iron was mastered in China, from where this term (through Tatar-Mongol mediation) came to Russia [1]. In the 10th century, cast iron coins appeared in China, but bronze coins remained in widespread use until the 19th century [2]. In the 11th century, the cast iron spire of the Lingxiao Pagoda was erected. The finds of cast iron boilers of the Golden Horde (Tula region) date back to the 14th century [3], but in the territory of Mongolia (Karakorum) the Mongols knew how to make cast iron boilers back in the 13th century [4]. In 1339 (during the Hundred Years War) during the defense of the French city of Cambrai Cast iron cannons were already used along with bronze ones. In 1403, a cast iron bell was cast in China (Beijing) [5]. Since 1411, the British began to arm their ships with cast iron cannons [6]. In the same 15th century, cast iron cores began to be cast in Flanders, which replaced stone ones [7]. In the 16th century in Russia (under Ivan the Terrible), guns began to be made from cast iron [8]. Due to the lack of cast iron such properties as malleability, its widespread production became possible thanks to the introduction of blast furnace technology. Cast iron cannons appeared among the Manchus only in 1631 [9], and in China they were known since the Ming Dynasty [10], which lost power in 1644. In 1701, the Kamensky Iron Foundry in the Urals (Russia) produces the first batch of cast iron ( 262 kg). In the Urals, iron casting turned into a folk craft (Kasli casting). In the 18th century, the first cast iron bridge appeared in England (in Russia, a cast iron bridge appeared only at the beginning of the 19th century). This was made possible thanks to Wilkinson's technology. In the same century, rails began to be made from cast iron [11] (Cast iron wheel line). In addition to industrial use, cast iron continued to be used in everyday life. In the 18th century, cast iron pots appeared, which began to be widely used in Russian stoves [12]. By the end of the 18th century, Russia took first place in the production of cast iron and produced 9,908 thousand pounds of cast iron, while England - 9,516 thousand pounds, then went France, Sweden, USA. [13] In 1806, Great Britain smelted 250 thousand tons of cast iron, ranking first in the world in its production, and by the middle of the 19th century, half of the world's cast iron production was concentrated in Great Britain. However, in 1890, the United States took first place in cast iron production [14]. The technology of the Bessmer process (1856) and the open-hearth furnace (1864) made it possible for the first time to produce steel from cast iron. In the 19th century, cast iron was widely used for the manufacture of Victorian fireplaces [15], as well as decorative elements (for example, the cast iron grate of the monument to Alexander II, 1890). Thanks to the production of small sculptures and openwork items made of cast iron, the Kusinsky and Kasli factories became widely known. The development of molding methods for casting complex artistic castings at a plant in the village of Kasli led to the creation of a method for producing core molds, which is still used today, especially in machine tool building. [16] Also in the 19th century, London's 12-inch water and sewer pipes were made from cast iron [17] . However, with the advent of rifled weapons (Armstrong's Gun, 1854), steel again begins to displace cast iron. Among the metals produced in the same 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 shape 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 impact, 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. 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 cast 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 in it, which does not allow 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 ranges from 1,150 to 1,200 °C. Cast iron has proven itself to be a universal, 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 can be very similar. However, there are the following main differences between them:

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

cast iron is heavier than steel, since its density is greater

Other questions from the category

mechanical energy upon impact with the Earth turned into heat. 2) Find the power of the electric heater, using which you can boil 2 liters of water in a period of time 10 minutes. Initial water temperature t=20C. Efficiency = 60%

Source: http://schemy.ru/info/chto-tjazhelee-stal-ili-chugun/

How to choose a frying pan by material, shape, size, type of coating

Without a good frying pan, it is almost impossible to prepare tasty and high-quality home-cooked food. With its help, ingredients for various dishes are fried and lunch is heated. For this reason, it is very important to know how to choose the right frying pan so that you can then offer your loved ones the most delicious dishes. It is necessary to imagine all the important features of a high-quality product.

Varieties

Ideally, the kitchen should have several frying pans that differ in shape, material, wall thickness and other indicators. So, for example, any option with a non-stick coating is suitable for cooking scrambled eggs, and a grooved model is recommended for frying meat. To make it easier for housewives to choose, it’s worth familiarizing yourself with the main types of frying pans:

1. Classic frying pan. This option is in greater demand than others. It comes in different sizes or dimensions, most often the utensil is equipped with a removable handle that allows you to put it in the oven.
2. Grill. It is characterized by a ribbed bottom, allowing food to be fried in stripes. Typically, a round or rectangular frying pan has solid metal handles. The advantage over other types of products is that less oil is required for frying.
3. Grill gas. Manufactured for gas stoves. During cooking, it is advisable to pour water into the tray, then the food under the lid will bake quickly and evenly. Oil may not be used. The released fat does not come into contact with fire or food.
4. Brazier. This is the deepest frying pan, most often used for cooking in the oven. It is made from heat-resistant metals. The food in it turns out very tasty, does not burn, and is evenly fried.
5. FOC. It has thick walls and handle ears, has a small bottom, the walls expand upward. The product is intended for preparing liquid or paste-like dishes.
6. Saucepan. It is a thick-walled hybrid of a saucepan and a frying pan. It is equipped with a heat-resistant lid and a scale for determining the amount of water. As a rule, liquid food is prepared in it.
7. Pancake maker. It has low and thin walls. Well suited for dishes that require careful turning with a spatula. Pancakes, pancakes, potato pancakes are perfectly prepared in it.

In addition to the options listed, there are other, more interesting frying pans, for example, paellera, oval, tapa.

Classic frying pan

Grill

brazier

FOC

Saucepan

Pancake maker

Manufacturing materials

It is equally important to compare different types of frying pans based on materials of manufacture. Aluminum products, for example, are characterized by lightness, availability, and a wide range. They are not too expensive, but you won’t be able to use them for a long time. Aluminum is not very strong.  

The best options are ceramic frying pans. They are resistant to high temperatures, do not deform, and are perfectly resistant to being in the oven. The products have a long service life. Copper pans most often have a non-stick stainless steel coating. They are reliable and last a long time. The products are attractive from an aesthetic point of view, resistant to high temperatures or temperature changes.  

A stainless steel frying pan most often becomes the main item for equipping a kitchen. It has a shiny glossy surface, in addition, such utensils are very beautiful. If you choose high-quality cookware, you should know that a cast iron frying pan with a non-stick coating has an almost unlimited service life. It is perfect for any type of oven. Food does not burn on it, and the surface cannot be damaged or burned.  

In order for the dishes to be of excellent quality, experts recommend choosing frying pans with a bottom thickness of at least 3 mm. For a pancake maker, it is allowed to reduce the indicator to 1.5 mm. The wall must be at least 2 mm thick. Thick products allow food to be heated evenly, so the dishes turn out more tasty.

Aluminum

Ceramics

Copper

Stainless steel

Cast iron

Coverage type

When choosing a frying pan, the type of coating is also of great importance:

1. Marble and granite are highly reliable and have a long service life. They are resistant to high temperatures or temperature changes. They retain heat for a long time, which allows owners of stoves of the corresponding type to save electricity.
2. The tin type is usually intended for copper products and helps protect them from oxidation. But you need to remember that metal melts easily, so you need to monitor the temperature and the time the pan is on the fire.
3. A product with a ceramic coating allows you to fry food at high temperatures without fear of burning. It is easy to clean, but you need to clean it carefully, since the dishes are quite fragile.
4. The titanium or diamond version is characterized by the greatest strength. It is durable, resistant to wear or damage, but is expensive.
5. Non-stick steel coating is usually reserved for copper pans. It allows you to quickly fry foods and perfectly protects them from burning.
6. The enameled variety is durable and will last a long time, as it is resistant to various types of damage. The food warms up slowly, but turns out very juicy.
7. Non-stick Teflon coating of frying pans is the most common. You don't need to use a lot of oil when frying it, but it gets damaged easily. In addition, the coating overheats (from 250°), beginning to release toxic substances.

Granite

Marble

Tin

Ceramics

Titanium

Diamond

Steel

Enamel

Teflon

Shapes and sizes

The most commonly produced types of pans are rounded. They vary in side height and are very convenient for cooking. Utensils in the shape of a square or rectangle are slightly less in demand; they are usually equipped with a ribbed bottom.

The device makes it possible to fry a large number of products, so it is intended for large families or professional cooking. The product fits easily into the dishwasher and is suitable for gas stoves.

An elliptical frying pan with high sides and a thick bottom is most often made for cooking, frying or stewing fish dishes. Dishes with low sides are recommended for vegetable delicacies.

The standard size of products with different sides ranges from 18 to 32 cm in diameter. The height of the most popular pancake pans ranges from 2 to 10 mm. In the ranking, such options most often take first place.

When choosing utensils, you should take into account the number of family members. It is important to decide whether to take 1 large frying pan or several small ones. It is also advisable to take into account the capacity of the stove and the size of its burners. It is important that they fit several pans of different diameters.

Round form

Square

Standard sizes

Handle and lid

When cooking, sometimes it is necessary to remove the container from the heat and cover it with a lid, so the handle is of paramount importance. As a rule, it is made from heat-resistant plastic or metal. Types of handles:

1. Cast. They are one- or two-sided. They are usually used for heavy products, so they are not always in demand.
2. Removable. They are often made from plastic, which is resistant to high temperatures. The handles are separated by pressing a special button.
3. Foldable. This option allows you to easily fit the frying pan into any kitchen cabinet. However, folding handles do not last long because they break quickly.
4. Twist-out. These are safe handles that are firmly attached to a special thread. They get dirty quickly and are difficult to clean from grease stains.

The most common material for the lid is glass . Through it you can see what is happening to the dish. It also creates optimal cooking conditions. The silicone product can be quickly cleaned with any composition; it does not deform when heated. The lid tightly covers the container while cooking. The cast iron version is very strong, reliable and durable, but it is expensive. The product is heavy and susceptible to rust.

The stainless steel frying pan with the corresponding lid option is very durable and cannot be deformed. It is especially suitable for cookware with non-stick coating and thick bottom. Disadvantages of the lid: does not retain heat very well, not suitable for the microwave.

Cast

Removable

Folding

Twist-out

Choice depending on the type of stove

It is important to select the product depending on what stove you plan to cook on: 

1. For a gas stove, it is better to choose a frying pan whose bottom thickness starts from 5 mm, otherwise the cookware will be deformed under the influence of the flame and will quickly fail. It is recommended to opt for multi-layer options with a corrugated surface, made from aluminum, copper or cast iron.
2. An induction hob requires a model with a ferrimagnetic bottom and a special conformity mark. The best pans are those that have a diamond, ceramic or titanium non-stick coating. In size they must strictly correspond to the diameter of the burner.
3. For cooking on a glass-ceramic type of stove, products with a special bottom are required. It should be heat-resistant, matte, flat, dark. Pans without a non-stick coating should not be used, as they will leave marks on the surface.  

For electric stoves, cookware with a smooth, even bottom without defects or deformations is suitable, but aluminum ones cannot be used due to low heat resistance. The size of the product must match the size of the burner.

For gas stove

For induction

For glass ceramic

The best manufacturers

It’s worth choosing the best frying pans for your home, so you need to familiarize yourself with the products of leading manufacturers of kitchen utensils. The companies listed in the table produce products of the highest quality. However, not all the frying pans presented here are very expensive.  

Firm	Product Features	Main advantages
Tefal	It has virtually no negative reviews of its products. It is not too expensive and has a long service life. The best frying pan for home use is Tefal Extra 28 cm.	Universal frying pans have a Teflon coating and are characterized by high thermal stability, up to 260 °C. They are usually equipped with a heating indicator. No oil is needed for cooking, which helps save money and allows you to follow a diet.
Rondell	They belong to the wok type and are often produced in a round shape. The product has high sides and the handle can be easily detached. The kit includes a convenient lid.	The frying pans are very reliable, durable, and do not emit harmful substances. They are suitable for any type of stove.
Fissler	If you choose a non-stick frying pan, it is better to choose the products of this manufacturer. All utensils are made of high quality stainless steel and equipped with comfortable handles.	The products are characterized by durability and are lightweight. The pans can be used for induction cookers.
Neva Metal Tableware	Produces aluminum cast products. All of them have a non-stick coating and are suitable for gas, glass-ceramic and electric stoves.	They are safe for health and do not emit harmful substances, which makes them convenient for people suffering from various diseases. Dishwasher safe.

It is important to remember that products from well-known manufacturers are often counterfeited, so before choosing a frying pan, it is important to find places that value their reputation. Even high-quality dishes will not last long if you do not provide them with proper care. It is important to study the manufacturer's instructions and not violate them.

Tefal

Rondell

Fissler

Neva Metal Tableware

Source: https://posuda-expert.ru/skovorodki/164-kak-vybrat

Fireplace inserts: cast iron versus steel

Those wishing to acquire a fireplace will have to understand a huge number of nuances. For example, there are steel and cast iron fireboxes on the market, but each type has its own characteristics and advantages.

In general, it is worth understanding that fireboxes made of steel and cast iron have similar performance properties. But there are also differences dictated by the characteristics of a particular metal. Cast iron takes a long time to heat up and gives off heat to the surrounding air over a long period.

Note: if you decide to order cast iron fireboxes at the best price, we recommend looking at the catalog on the website kaminchi.ru.

Steel, on the other hand, heats up and cools down very quickly, so a fireproof lining is required to increase the heat capacity of the fireplace. Without it, the metal quickly deforms and burns out. In general, the fireplace insert should be considered a combined one, because for its manufacture alloy steel, ceramics are used, and some of the elements are even cast from cast iron.

Aesthetics or functionality?

When choosing a steel firebox, you can count on a very diverse design and even a very non-standard design. In addition, it is possible to manufacture the structure to an individual size. Another advantage worth noting is the fact that the internal lining can be replaced with a new one.

Cast iron fireboxes are simpler in terms of design, but much more practical. Such models have the following advantages:

• resistant to deformation at high temperatures;

• can be operated in continuous combustion mode;

• high strength, therefore low risk of burnout;

• virtually no deformation even when overheated;

• excellent efficiency – efficiency reaches 80%;

• longer service life.

That is, when choosing between steel and cast iron, you must decide what is more important to you: a designer fireplace or a more powerful and durable one.

Some features of cast iron fireboxes

Many people prefer a cast iron firebox not only because of its excellent performance, but also because of its simpler installation. It is quite easy to assemble such a fireplace - some do it even without the help of specialists.

Another feature in favor of a closed cast iron structure is the ability to move the firebox to another room or even home. Of course, this is not very easy, but if necessary, you can dismantle the structure without any problems.

If you want to use a fireplace to heat a building, there are models with a water circuit. Such a system can fully replace the heating system. A very convenient option for a cottage or guest house.

Source: http://sarreg.ru/kaminnye-topki-chugun-protiv-stali-175820.html

What is heavier, steel or cast iron?

The metallurgical industry products often used in everyday life are cast iron and steel. Both materials are a unique alloy of iron and carbon. But the use of identical components in production does not endow the materials with similar properties. Cast iron and steel are two different materials. What are their differences?

Steel

To make steel, you need to fuse iron, carbon and impurities. In this case, the carbon content in the mixture should not exceed 2%, and the iron content should not be less than 45%.

The remaining percentage in the mixture can be alloying elements (substances that bind the mixture, for example, molybdenum, nickel, chromium and others). Thanks to carbon, iron acquires strength and extreme hardness.

Without his participation, a viscous and plastic substance would be obtained.

Cast iron

Iron and carbon are also fused together in the production of cast iron. Only the content of the latter in the mixture is more than 2%. In addition to the listed components, the mixture contains permanent impurities: silicon, manganese, phosphorus, sulfur and alloying additives.

The difference between cast iron and steel is as follows:

1. Steel is stronger and harder than cast iron.
2. Cast iron is lighter than steel and has a lower melting point.
3. Due to its lower carbon content, steel is easier to process (welding, cutting, rolling, forging) than cast iron.
4. For the same reason, cast iron products are made only by casting.
5. Products made of cast iron are more porous (due to casting) than those made of steel, and therefore their thermal conductivity is much lower.
6. Typically, art products made from cast iron are black and matte, while those made from steel are light and shiny.
7. Cast iron has low thermal conductivity, while steel has higher thermal conductivity.
8. Cast iron is the primary product of ferrous metallurgy, and steel is the final product.
9. Cast iron is not hardened, but some types of steel must be subjected to a hardening procedure.
10. Products made of cast iron are only cast, and products made of steel are forged and welded.

The difference between cast iron and steel

Question:

What is the difference between cast iron and steel, and why?

Answer:

Oddly enough, despite the abundance of specialized literature on this topic, we are often asked the following question: How is cast iron different from steel? Briefly and in general terms, we can say that in terms of composition, cast iron differs from steel in its higher carbon content, in terms of technological properties - better casting qualities and low ability for plastic deformation. Cast iron is generally cheaper than steel.

And if in more detail, then read the classics, dear ones! Many volumes are devoted to materials science and metallurgy of ferrous alloys. As an example, I give an excerpt from the fundamental work of A.P. Gulyaev. "Metal science":

“Steel is an iron-carbon alloy containing less than 2.14% carbon.

However, the indicated limit (2.14% C) applies only to double iron-carbon alloys or alloys containing a relatively small number of impurities.

The question of the boundary between steels and cast irons in high-alloy iron-carbon alloys, i.e. containing even greater amounts of elements other than iron and carbon is controversial.

In the light of modern technology, iron-based alloys are known and have recently become widespread, in which there is very little carbon and it is even a harmful element; however, such alloys are also called steels.

To avoid terminological confusion, it is customary to consider alloys containing more than 50% iron as steels (cast iron) and not to call them alloys, but to call alloys containing less than 50% iron.

It’s not scientifically rigorous, but it’s technically clear.”

What is the qualitative difference between steel and cast iron?

Cast iron and steel products from the metallurgical industry are used both in everyday life and in production. Both materials are unique alloys of iron and carbon.

Everyone knows that iron is mined from the depths of the earth in huge quantities. But it is impossible to use it in its pure form; this element is too soft and therefore unsuitable for the manufacture of high-strength products. Therefore, for industrial, construction and household purposes, it is not iron in its pure form that is used, but its derivatives - cast iron and steel.

How do cast irons differ from steels?

Iron is mined from the depths of the earth more than any other metal.

But you haven't seen pure iron. This silvery metal is too soft and therefore unsuitable for making products (with the exception of electromagnet cores).

In industry, in construction, and in everyday life, they use not pure iron, but a wide variety of iron alloys - cast iron and steel. They differ greatly from each other in their properties.

With a steel pen you can easily scratch your name on a cast iron frying pan.

The cast iron fragment will only slide along the surface of the steel skates and will not cause any harm to them. The vast majority of steels are harder than cast iron. No matter how hard you try, you will not be able to bend a cast-iron frying pan: with great effort it will not hold up - it will crunch, break, but will not bend.

The blade of a steel dinner knife bends and straightens again. Cast iron is brittle, but steel is elastic. However, the elasticity of steel has its limit: the blade of a knife cannot be bent into an arc - it will break.

Every day, when you wind your watch, you wind the watch spring. The wound spring unwinds, pulls the gears and wheels - the clock runs.

They serve you for many years, and day after day, 365 times a year, the spring twists and unwinds without losing its elasticity. As we have already said, such springs are made of especially elastic steel.

The drill bit of the drilling machine rotates rapidly, piercing deeper and deeper into the steel plate.

After a short time, a through hole appears in the slab. Such drills, as well as cutters, are made of special, high-speed steel. Metallurgists produce hundreds of different grades (“grades”) of steel and dozens of grades of cast iron.

All of them certainly contain carbon. Therefore, cast irons and steels are called iron-carbon alloys. Cast iron contains the most carbon (more than 2%).

Steels contain less than 2% carbon; There is very little of it in soft steels or malleable iron. Sheets of roofing iron are rolled from malleable iron and wire is drawn; Nails are made from iron wire using automatic presses.

A blow with a hammer-punch on the tip of the wire protruding from the matrix - and it is flattened into the head of the future nail. A blow from the biting knives - and a finished nail with a pointed end is separated from the wire.

The softness and pliability of malleable iron compared to hard steels and cast irons is useful not only when making wire or nails from it, but sometimes also when using products made from it.

  Boiler steel what is it?

Thus, shoe nails, in order not to scratch the floor, must wear out along with the leather. In terms of chemical composition, cast iron and steel differ from each other not only in carbon content. Iron-carbon alloys also contain small quantities of other elements - non-metals (silicon, phosphorus, sulfur) and metals.

By increasing the content of some elements, decreasing the content of others, introducing various alloying metals (chrome, vanadium, titanium, etc.), metallurgists obtain a variety of special steels.

Some of them have amazing elasticity, others are “superhard”, and others do not corrode either in air or in water.

Source: https://varimtutru.com/chto-tyazhelee-stal-ili-chugun/