From 0.10 to as much as 2% of the alloy contains carbon, which influences how hard the steel may be toughened. Manganese, molybdenum, chromium, nickel, and other alloys may be added to increase hardenability and other properties including corrosion resistance.
Cast irons are iron/carbon alloys with a carbon content more than 2%, and they are not malleable unless in the form of malleable and ductile cast iron, which is a unique case.
Metals such as steel are known for their strength, resistance to wear and abrasion (such as fatigue, impact, and creep), as well as their ability to transfer electricity and heat. They are also heavy and resistant to temperature changes. In a furnace, impurities in pig iron are removed to create steel.
Iron and carbon are the primary constituents of steel, a metal alloy. Depending on the quantity of carbon and the addition of alloys, there are a number of various classes of steel.
More than 3,500 distinct grades of steel exist, each with a unique combination of physical, chemical, and environmental characteristics.
Iron and carbon are the basic building blocks of steel. Each steel grade’s qualities are determined by its carbon content, as well as its impurities and other alloying components.
Most commonly used grades of steel have carbon content between 0.1 and 0.25 percent, which falls within the range of 0.01 and 0.5 percent.
Although manganese, sulphur, phosphorus, and phosphorus are present in all grades of steel, they are more prevalent in lower grades. Manganese, on the other hand, has a positive influence on steel’s strength and durability; phosphorus and sulphur are detrimental.
Carbon steel, alloy steel, stainless steel, and tool steel are the four main categories of steel based on chemical structure and physical attributes that you should know about before making a steel purchase. We’ll Follow an explanation of the many forms of steel.
Carbon Steel
Carbon steel accounts for the vast bulk of daily steel production. Steel in its most basic form. In terms of carbon content, it may be further split.
Low-carbon steel has a maximum carbon content of 0.3 percent. It’s the most popular kind of carbon steel out there. It is a low-cost solution with a wide range of potential uses.
Although it has a relatively low tensile strength compared to other types of carbon steel, it is very malleable and easily bendable.
Shipbuilding, wiring, automobile bodywork, and various residential appliances all benefit from this material’s flat-rolled sheets and strips. Hard yet not brittle makes it ideal for fence, gates, and railings.
A medium-carbon steel, or mild steel, has a carbon content of between 0.3% and 0.6%. It is more difficult to mould, weld, and cut than low-carbon steel, despite its higher strength.
Silicon and manganese are inexpensive and easy to add to this product to improve its quality. In the construction of buildings and bridges, mild steel is used for axles, gears, gear shafts, railways, pipes, couplings, and in automobiles, refrigerators, and washing machines as well.
Carbon content ranges from 0.6 percent to 1 percent in high-carbon steel, commonly known as carbon tool steel. Because of its sensitivity to impurities, notably sulphur, and the brittleness and crumbliness that results when working with it, stainless steel is not recommended for heat treatment.
To make cutting instruments like blades, punches, and springs, as well as high-strength wires, this material has a higher tensile strength than the previous two and is employed for this purpose.
Last but not least, ultra-high carbon steel has a carbon content ranging from 1.25 to 2 percent and is both brittle and very hard. Cutting tools, huge machine parts, hot water radiators, and industrial castings all use this material since it can’t be cold-worked. It’s also called as “cast iron” in certain circles.
Corrosion-prone carbon steel has a dull, matte finish. Manganese, silicon, and copper are all alloys that may be added to carbon steel.
Carbon steel comes in three basic forms: low carbon steel, medium carbon steel, and high carbon steel. The most prevalent kind of steel is low carbon steel, which has a carbon content of less than.30 percent.
Medium carbon steel is more stronger than low carbon steel since it includes up to.60 percent carbon as well as manganese. The strongest kind of steel, high carbon steel contains up to 1.5% carbon steel and is notoriously difficult to work with.
90% of all steel is made from carbon steel, which contains just trace levels of alloying metals. In terms of carbon content, carbon steels may be divided into three subcategories:
- Carbon content in Low Carbon Steels/Mild Steels is as low as 0.3 percent.
- The carbon content of medium carbon steels ranges from 0.3 to 0.6 percent.
- Steels with more than 0.6 percent carbon are known as high-carbon steels.
Alloy Steel
For example, nickel, copper and aluminium alloy steels are often used. Because of their lower cost, alloy steels are often employed in mechanical applications such as automobile components, pipes, and motors. As the concentration of the constituents in the alloy steel increases, so does its strength and properties.
Manganese, silicon, nickel, chromium, copper, and aluminium are some of the alloying elements found in alloy steels, which may be used to alter the steel qualities, such as hardenability, corrosion-resistance, ductility and formability.
Pipelines, automobile components, transformers, power generators and electric engines are all examples of alloy steel applications.
Stainless Steel
There are a wide variety of stainless steel goods available, including kitchen equipment, countertops, and cooking utensils. It contains a little amount of carbon. Stainless steel is made up of chromium, nickel, and molybdenum alloys.
High temperatures are no match for stainless steel’s strength. As there are more than 100 grades of stainless steel, you may tailor it to suit your specific needs.
For corrosion resistance, stainless steels typically include 10% to 20% chromium as the principal alloying element. Steel, which has a chromium content of above 11%, is 200 times more corrosion resistant than mild steel.
Based on their crystalline structure, these steels may be broken down into three distinct categories:
- Alloys with a low carbon content (less than 0.8%) are called austenitic steels. Austenitic steels are non-magnetic, heat-treatable, and often contain 18 percent chromium. Because they make up the majority of stainless steels sold worldwide, austenitic steels are often found in food processing equipment, culinary utensils, and pipelines.
- Nickel, chromium and other alloying elements are present in ferritic steels. They are also known as ferritic steels because they contain less than 0.1 percent carbon. It is possible to harden these magnetic steels by cold working rather than heat treatment.
- This kind of steel has between 11-17% chromium, less than 0.4% nickel, and up to 1.2% carbon. Martensitic steels Knives, cutting tools, and dental and surgical equipment all make use of these magnetic, heat-treatable steels.
Tool Steel
Hard, heat- and scrape-resistant, tool steels are a popular choice. Equipment such as stamping, cutting, and mould-making tools are often made from tool steels.
Vanadium, cobalt, molybdenum, and tungsten all play a role in tool steel’s increased toughness and heat resistance. Hammers are another typical usage for them. There are a variety of steel grades that may be utilised for a variety of different purposes.
In order to boost heat resistance and longevity, tool steels include different amounts of tungsten, molybdenum, cobalt, and vanadium.
In addition to their forms and associated uses, steel products may be classified into other categories:
- These products include bars and rods, rails and wires as well as angles, pipelines, and other forms or sections. The automobile and construction industries both often use these goods.
- Plates, sheets, coils, and strips are examples of flat products. Parts for automobiles and home appliances as well as packaging, ships, and construction are all common places for these materials to be found.
- As pipe materials, these other products include flanges, valves, and fittings.
Plain Carbon Steel
Plain carbon steel has no significant alloying ingredient other than carbon and is classed as low-, medium-, or high-carbon depending on the carbon concentration.
It is used for structural forms, gears, cold-forged components, and weldable tube in the intermediate and higher levels in the production of low-carbon steel ( 0.3 percent C).
For gears, shafts, connecting rods, and seamless tubing, medium-carbon steel (0.3 to 0.5 percent C) is sometimes referred to as machinery steel. For springs, knives and hand tools, taps and milling cutter, wire drawing dies, etc., high-carbon steel (> 0.5 percent C) is employed.
To approximate the carbon content, the last four digits of the AISI numbering system indicate ordinary carbon steel as 10xx. As an example, 1010 is a carbon mild steel with 0.08% to 0.13% carbon. The designation 11xx would be given to steel suitable for free-machining.
Rapid cooling is necessary to harden carbon steel. Remaining stresses and distortions may lead to poor mechanical properties and reduced ductility, among other things.
Alloy Steel
Steel’s hardenability is mostly determined by its carbon content, but specific alloying elements added to the steel may lessen the stress of heat treatment, which is useful when quenching distortion is a problem in thin-walled, complicated structures.
For alloy steels, hardenability is a phrase that describes how far the metal can be honed, with carburising steel hardening most of the way to the surface and through-hardening steel being able to go deeper into the metal’s core.
Steels with manganese are classified 13xx in the AISI numbering system, whereas those with nickel are labelled 2xxx, nickel-chromium steels are 3xxx, and molybdenum steels are 4xxx, and so on up to 9xxx for silicon-manganese steels.
Alloy steels may be hardened by quenching them in oil, rather than water, as is the case with normal carbon steels. As a result, the material’s core may be hardened to a greater extent and with less deformation.
Low Alloy Steel
HSLA, or High-Strength Low-Alloy, steel, is a kind of metal that has a higher strength-to-weight ratio than ordinary carbon steel and is often used in mobile equipment. It may be cold-formed and welded easily. Abrasion, fatigue, and corrosion resistance are all better with this material than with ordinary steel.
It’s also employed in the construction of ships and off-road vehicles because of its low-alloy content. Some additional low alloy steels are available, however, for special requirements, such as low-temperature toughness or the production of protective weathering coatings on ornamental steel used for building facades.
Stainless Steel
Iron and chromium alloy stainless steel includes between 10% and 30% chromium, which makes the metal highly resistant to corrosion. Stainless steel comes in a wide variety of grades, but only about a dozen of them are regularly utilised.
Corrosion resistance, ease of cleaning, and formability are all advantages of AISI Type 304 SS, a stainless steel with chromium-nickel constituents and low carbon content that is often used in kitchen sinks. If you’re going to be exposed to saltwater, brine or sulfuric acid in the industrial environment, you’re going to want to select AISI Type 316 SS since it’s more resistant to chemical assault than Type 304.
Alloy steel products and their applications
Alloy steels of varied compositions may be used to make a wide range of items. As an example, you may mention alloy steel pipes and tubes as well as the aforementioned alloy steel sheets and coils, as well as the alloy steel bars, rods, and wires, as well as the many other alloy steel components.
Alloy steels are widely used in a wide range of sectors, including transportation, manufacturing, mining, railroads, and machinery and equipment.
The Three Main Categories of Stainless Steel
Steel alloys may be categorised into three major categories:
Austenitic Stainless Steels
Among stainless steels, these are the most widely used. In comparison to other steel alloys, austenitic stainless steels have a greater chromium concentration, making them more corrosion resistant. Austenitic stainless steel alloys are also typically nonmagnetic, however this property might change with cold treatment.
Ferritic Stainless Steels
Austenitic alloys are the second most popular kind of stainless steel. Ferritic stainless steel, as its name suggests, is magnetic.
Through cold working, these alloys may be hardened and strengthened. Because of their lower nickel content, they are also more affordable.
Martensitic Stainless Steels
The least common stainless steel alloy group. These alloys have a high hardness but a lesser corrosion resistance than either ferritic or austenitic alloys.
This kind of stainless steel alloy might be appropriate for applications that need very high tensile strengths and strong impact resistance. These alloys may be coated with a protective polymer to increase their corrosion resistance when used in the aforementioned applications.
Within each category, there are a variety of stainless steel grades; the following are the most frequent types of each:
Common Types of Austenitic Stainless Steels
Grade 304 Stainless Steel
Marlin Steel’s bespoke wire basket designs commonly employ this kind of stainless steel due of its adaptability. The high tensile strength of grade 304 stainless steel (about 621 MPa) sets it apart from other steel alloys (90 ksi).
Grade 304, like other stainless steels, can withstand temperatures up to 870 °C. There are many uses for grade 304 stainless steel because of its high tensile strength and resistance to both heat and corrosion.
Grade 316 Stainless Steel
A typical austenitic stainless steel grade 316, it has a maximum usage temperature of 800 °C (1,472 °F) and a tensile strength of 579 MPa (84 ksi).
In spite of its lower tensile strength and temperature tolerance, grade 316 stainless steel is more resistant to chlorides (such as salt) than grade 304 alloy. The fact that it can withstand salt and other chlorides makes it an excellent option for any application requiring such exposure.
Ferritic Stainless Steels
Grade 430 Stainless Steel
Grade 430 stainless steel, although not as robust as the austenitic alloys noted above, has a particularly outstanding resistance to nitric acid. The tensile strength of 450 MPa (65 ksi) is lower than that of austenitic stainless steels, yet it’s still more than enough for many heavy-duty uses.
Grade 434 Stainless Steel
It has a tensile strength of 540 MPa (78 ksi) and a maximum working temperature of 815 °C (1,499 °F), making it a better choice than grade 430 stainless.
For high-temperature applications, grade 434 stainless steel is somewhat superior than grade 316 stainless, while being more durable than grade 430 stainless, The pitting resistance of grade 434 stainless steel is also superior than that of 430-grade stainless steel.
Martensitic Stainless Steel
Grade 420 Stainless Steel
Tensile strength may be as high as 586 MPa for grade 420 stainless steel that has been annealed (85 ksi). The tensile strength of this material increases to about 1,586 MPa once it has been toughened and stressed (230 ksi).
Grade 420 stainless steel, although not as chemically resistant as austenitic and ferritic stainless steels, does have high resistance to mild acids, water, certain alkalis, and food compounds-which is why it is often used for cutlery. 420 stainless steel is an excellent option for applications that need high tensile and impact strength.
Steel has taken over a wide range of sectors. There are many things built on top of it, since it is present in most of the gear individuals own. Steel comes in a wide range of types, so you can be sure to find something to meet your requirements.
Conclusion
Metals, such as steel, are prized for their durability, resilience against wear and abrasion, and efficiency as heat and electricity conductors. The physical, chemical, and environmental properties of the more than 3,500 different grades of steel available today make them all but incomparable to one another. Chemical composition and physical properties distinguish the four main types of steel: carbon steel, alloy steel, stainless steel, and tool steel. Ships, electrical wiring, car bodies, and other home appliances are all common places to find carbon steel in use. Carbon content ranges from low to high, with low carbon steel being the most common.
Molding, welding, and cutting low-carbon steel, which has a carbon content of less than 0.30 percent, is more challenging. Stronger than low carbon steel, medium carbon steel contains up to 60% carbon and sometimes manganese. High carbon steel, which can contain up to 1.5% carbon steel, is notoriously difficult to work with. For their strength and durability, alloy steels are put to use in a wide variety of mechanical settings, including automobile parts, pipes, and motors. Manganese, silicon, nickel, chromium, copper, and aluminium are just some of the alloying elements that can be used to modify the steel’s properties.
Made from iron, nickel, and chromium, stainless steel resists corrosion at a rate 200 times that of mild steel. Non-magnetic, heat-treatable, and typically containing 18% chromium, austenitic steels have many desirable properties. Due to their low carbon content, ferritic steels can be hardened through cold working rather than heat treatment. Cutting tools, such as knives and scissors, as well as dental and surgical instruments, can all benefit from the toughness of martensitic steels. Tungsten, molybdenum, cobalt, and vanadium are all added to tool steels in varying concentrations to increase their toughness and resistance to high temperatures.
Flat products, bars and rods, rails and wires, angles and pipelines are all examples of steel products. Plain carbon steel is classified as low-, medium-, or high-carbon based on the concentration of carbon; it contains no other significant alloying ingredient. While carbon content is the primary factor in determining an alloy steel’s hardenability, certain alloying elements added to the steel may mitigate the effects of heat treatment. Carbon steel must be cooled quickly to prevent the formation of residual stresses and distortions that can reduce the material’s mechanical properties and make it less malleable after hardening. In contrast to regular carbon steels, the strength-to-weight ratio of alloy steels is increased through quenching in oil rather than water.
They find application in many fields, such as logistics, production, mining, rail travel, and heavy industry. There are three primary types of stainless steel, and they are referred to as austenitic, iron and chromium alloy, and stainless steel, respectively. Austenitic stainless steels are exceptionally resistant to corrosion because they contain a higher percentage of chromium. There are many types of stainless steel, but only a handful are used on a consistent basis. Three main families of stainless steel alloys are used most frequently: martensitic, austenitic, and ferritic.
Martensitic alloys are well-suited for uses requiring high tensile strengths and strong impact resistance due to their high hardness but lower corrosion resistance. While ferritic alloys are more resistant to chlorides, austenitic alloys are more versatile and can withstand temperatures up to 870 °C. Grade 430 stainless steel is superior to grade 434 stainless steel in high-temperature applications due to its higher tensile strength (450 MPa; 65 ksi) and maximum working temperature (815 °C; 1,499 °F). Because of its high tensile and impact strength, as well as its resistance to mild acids, water, certain alkalis, and food compounds, grade 420 stainless steel is a great material choice for many different uses. There are many varieties of steel, so it should be simple to find one that suits your needs.
Content Summary
- Carbon steel, alloy steel, stainless steel, and tool steel are the four main categories of steel based on chemical structure and physical attributes that you should know about before making a steel purchase.
- A medium-carbon steel, or mild steel, has a carbon content of between 0.3% and 0.6%.
- Rapid cooling is necessary to harden carbon steel.
- For alloy steels, hardenability is a phrase that describes how far the metal can be honed, with carburising steel hardening most of the way to the surface and through-hardening steel being able to go deeper into the metal’s core.
- Steel alloys may be categorised into three major categories:Austenitic Stainless SteelsAmong stainless steels, these are the most widely used.
- The least common stainless steel alloy group.
- These alloys have a high hardness but a lesser corrosion resistance than either ferritic or austenitic alloys.
- This kind of stainless steel alloy might be appropriate for applications that need very high tensile strengths and strong impact resistance.
- There are many uses for grade 304 stainless steel because of its high tensile strength and resistance to both heat and corrosion.
- Grade 430 stainless steel, although not as robust as the austenitic alloys noted above, has a particularly outstanding resistance to nitric acid.
- Grade 434 Stainless SteelIt has a tensile strength of 540 MPa (78 ksi) and a maximum working temperature of 815 °C (1,499 °F), making it a better choice than grade 430 stainless.
- For high-temperature applications, grade 434 stainless steel is somewhat superior than grade 316 stainless, while being more durable than grade 430 stainless, The pitting resistance of grade 434 stainless steel is also superior than that of 430-grade stainless steel.
- Tensile strength may be as high as 586 MPa for grade 420 stainless steel that has been annealed (85 ksi).
- 420 stainless steel is an excellent option for applications that need high tensile and impact strength.
- There are many things built on top of it, since it is present in most of the gear individuals own.
- Steel comes in a wide range of types, so you can be sure to find something to meet your requirements.
FAQs About Metal
What Are Different Types of Steel Used For?
Medium-carbon steel (0.3-0.5% C) is used for gears, shafts, connecting rods, seamless tubing, etc. and is sometimes called machinery steel. High-carbon steel (> 0.5% C) is used for springs, knives and handtools, taps and milling cutters, wire-drawing dies, etc. and is sometimes called tool or spring steel.
How is steel named?
Carbon steel
Carbon steels and alloy steels are designated a four digit number, whereby the first digit indicates the main alloying element(s), the second digit indicates tg (top grade) element(s), and the last two digits indicate the amount of carbon, in hundredths of a percent (basis points) by weight.
Why Is Steel So Strong?
The material is hardened and can withstand much more pressure. In short, steel is so strong because the carbon atoms stop the iron atoms from moving past one another. The compromise is that steel is more rigid and less flexible than iron as a result.
How Are Steel Classified?
Steel can be classified by a variety of different systems such as the composition, manufacturing method, finishing method, product form, deoxidation practice, microstructure, strength level, heat treatment and quality descriptors.
Why Steel Is Used?
Steel is widely used in a number of sectors, such as construction, infrastructure, mechanical equipment, automotive and, increasingly, aerospace and other transportation sectors. While steel may seem hard and unmoving, it actually offers an attractive balance between strength and versatility of form.
