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Steel Types


Steel is an alloy of iron and other elements, primarily carbon, that is widely used in construction and other applications because of its high tensile strength and low cost.  (Wikipedia)


Below are some types of them.


1) Carbon steel
   Carbon steel, also known as carbon steel, is a carbon content of less than 2% WC iron carbon alloy. Carbon steel in addition to carbon generally also contain a small amount of silicon, manganese, sulfur, phosphorus can be divided into carbon steel, carbon steel, carbon tool steel and free-cutting structural steel. Carbon structural steel is divided into building structural steel and machine structural steel. Carbon steel can be divided into low carbon steel (WC ≤ 0.25%), medium carbon steel (WC 0.25% - 0.6%) according to carbon content. And high-carbon steel (WC> 0.6%) according to phosphorus and sulfur content can be divided into ordinary carbon steel carbon steel (phosphorus, sulfur is high), high-quality carbon steel (phosphorus, sulfur low); High-quality steel (phosphorus, sulfur lower) General carbon content of carbon steel is higher, the higher the hardness, the higher the strength, but the plastic is low

2) Carbon structural steel
   "Q" for the yield point "flexion" of the Chinese phonetic prefix, the number that the yield point value, for example, Q275, said the yield point is the value of the yield point, "Q" is the yield point, 275Mpa. If the mark after the mark letters A, B, C, D, then just different levels of quality, including S, P in turn reduce the amount of steel quality in turn. If the mark after the mark the letter "F" is boiling steel, marked "b" for the semi-killed steel, not marked "F" or "b" are killed steel. For example, Q235-A · F that yield point 235Mpa for A-grade boiling steel, Q235-C that the yield point of 235Mpa C-class killed steel carbon structural steel under normal circumstances are not heat treatment, and in the supply state directly. Usually Q195, Q215, Q235 steel, low carbon content, good welding performance, plasticity, good toughness, a certain intensity, often rolled into sheets, steel, welded steel pipe, used in bridges, construction and construction of ordinary screws, Nuts and other parts. Q255 and Q275 steel carbon content is slightly higher, higher strength, plasticity, toughness good, can be welded, usually rolled steel, steel and steel for structural parts and the manufacture of simple mechanical connecting rod, gear, coupling Section, wait for parts

3) High-quality structural steel
   This type of steel must also ensure that the chemical composition and mechanical properties. Its grade is the use of two figures that the average carbon content of steel in the mass fraction (WC × 10000). For example, 45 steel, said the average carbon content of steel was 0.45%; 08 steel, said the average carbon content of steel 0.08% Quality carbon structural steel is mainly used in the manufacture of machine parts. Generally have to go through heat treatment to improve mechanical properties. According to the different mass fraction of carbon, there are different uses. 08,08F, 10,10F steel, plasticity, high toughness, excellent cold forming performance and welding performance, often cold rolled into thin plate, for the production of instrument housings, cars and tractors cold stamping parts, such as car body, Cab, etc .; 15,20,25 steel for the production of small size, light load, the surface requires wear-resistant, heart strength requirements of the notice of carburizing parts, such as piston pin, model, etc .; 30,35,40,45 , 50 steel after heat treatment has a good overall mechanical properties, that is, high strength and high plasticity, toughness, for the production of shaft parts, such as 40,45 steel commonly used in the manufacture of automobiles, tractors crankshaft, connecting rod , General machine tool spindles, machine tool gears and other shaft parts of little stress; 55,60,65 steel heat treatment with high elastic limit, commonly used in the production load is not small, small size of the spring, Speed springs, spring plunger, cold coil spring, and so on

4) Carbon tool steel
   Carbon tool steel is basically free of alloying elements of high-carbon steel, carbon content of 0.65% -1.35% range, its low production costs, easy access to raw materials, good machinability, heat treatment can be high hardness and High wear resistance, it is widely used steel, used to manufacture all kinds of cutting tools, molds, but this type of steel red hardness is poor, that is, when the working temperature is greater than 250 ℃, the hardness and wear resistance of steel will be sharp Decline and loss of ability to work. In addition, carbon tool steel, such as made of large parts are not easy hardened, and prone to deformation and cracks

5) Easy to cut structural steel
   Easy to cut structural steel is added in the steel to make steel brittle elements, so that when cutting steel cutting brittle broken into pieces, which will help improve the cutting speed and prolong tool life. So that steel brittle elements are mainly sulfur, in the low-alloy structure of ordinary low-alloy steel used in lead, tellurium, bismuth and other elements of such steel WS WS in 0.08% -0.03% range, the amount of manganese in WMn 0.60% to 1.55%. Sulfur and manganese in the form of manganese sulfide, manganese sulfide is very brittle and lubricating effect, so that cutting easily broken, and help improve the quality of the surface processing

6) Alloy steel
   In addition to iron, carbon and a small amount of inevitable silicon, manganese, phosphorus, sulfur elements, but also contains a certain amount of alloying elements in the steel, silicon, manganese, molybdenum, nickel, Ge, alum, titanium , Niobium, boron, lead, rare earth and other one or more of the steel is called alloy steel alloy steel systems, with their own resources, production and use of different conditions, the development of foreign countries in the past, nickel, Ge Steel system, China is found to silicon, manganese, vanadium, titanium, niobium, boron, lead, rare earth alloy steel system alloy steel in steel production accounts for about ten percent, usually in electric furnace smelting Alloy steel, spring steel, bearing steel, alloy tool steel, high-speed tool steel, stainless steel, heat-resistant leather can not afford, electrical steel with silicon steel

7) Ordinary low-alloy steel
   Ordinary low-alloy steel is a kind of ordinary alloy steel containing a small amount of alloying elements (in most cases, its total W is not more than 3%). This steel is relatively high strength, the overall performance is better, and has corrosion resistance, wear resistance, low temperature and good cutting performance, welding performance in a large number of rare alloy elements to save conditions, usually 1 ton of ordinary low alloy steel can be The top 1.2-1.3 tons of carbon steel to use, its service life and use range is far more than carbon steel. Ordinary low-alloy steel smelting method can be used in the open hearth furnace, converter smelting, cost and carbon steel close

8) Engineering structure with alloy steel
   This refers to alloy steel for engineering and building structures, including weldable high strength alloy structural steel, alloy steel, alloy steel for railways, alloy steel for geological oil drilling, alloy steel for pressure vessels, high manganese wear resistant steel, etc. . This type of steel used as engineering and building structural parts, in the alloy steel, the total content of such steel alloy is low, but the production, the use of large

9) Mechanical structural alloy steel
   These steels are alloy steels suitable for the manufacture of machine and machine parts. It is in high-quality carbon steel, based on the appropriate to join one or several alloying elements, used to improve the strength of steel, toughness and hardenability. This type of steel is usually used after heat treatment. Mainly including the commonly used alloy steel and alloy spring steel two categories, including quenched and tempered alloy steel, surface hardening of the alloy steel, cold-formed plastic alloy steel. According to the chemical composition of the basic composition of the system can be divided into Mn steel, SiMn steel, Cr steel, CrMo steel, CrNiMo steel, Ni steel, B steel

10) Spring steel
   Spring in the impact, vibration or long-term use of cross-stress, so the requirements of spring steel with high tensile strength, elastic limit, high fatigue strength. In the process requirements of the spring steel has a certain hardenability, not easy to decarburization, surface quality carbon spring steel that is carbon content of WC in 0.6% -0.9% of the range of young carbon structural steel. Alloy spring steel is mainly silicon-manganese steel, their carbon content is slightly lower, mainly by increasing the silicon content Wsi to improve performance; in addition to Ge, tungsten, vanadium alloy spring steel. In recent years, combined with China's resources and in accordance with the requirements of new technologies for automobile and tractor design, new steel grades with elements such as boron, niobium and molybdenum have been developed on the basis of Si-Mn steel, which prolongs the service life of springs and improves spring quality

11) Bearing steel
   Bearing steel is used to make ball, roller and bearing rings of steel. Bearing in the work is to withstand a great deal of pressure and friction, so the requirements of bearing steel with high hardness and wear resistance, and high elastic limit. Bearing steel chemical composition uniformity, non-metallic inclusions content and distribution, carbide distribution requirements are very strict bearing steel, also known as high carbon steel, carbon Wc is about 1%, containing the amount of Wcr 0.5% to 1.65%. Bearing steel is divided into high-carbon Ge bearing steel, non-Ge bearing steel, carburizing bearing steel, stainless steel bearing steel, high temperature bearing steel and anti-magnetic bearing steel six categories

12) Electrical silicon steel
   Electrical industrial silicon steel is mainly used for the manufacture of electrical industrial silicon steel sheet. Silicon steel sheet is a great amount of steel used in the manufacture of motors and transformers. Silicon steel can be divided into low silicon steel and high silicon steel according to chemical composition. Low silicon steel Wsi1.0% -2.5%, mainly used to manufacture motor; high silicon steel Wsi3.0% -4.5%, generally used to manufacture transformers. Their carbon content Wc ≤ 0.06% -0.08%

13) Bridge steel
   Railway or highway bridge to withstand the impact load of the vehicle, the bridge steel requires a certain degree of strength, toughness and good anti-fatigue properties, and the surface quality of steel demanding. Bridge steel is often used alkaline flat furnace killed steel, the recent successful use of ordinary low-alloy steel, such as 16 manganese, 15 manganese alum nitrogen

14) Boiler steel
   Boiler steel is mainly used to manufacture superheater, the main steam pipe and boiler fire room heating surface with the material. The performance requirements of the boiler steel is mainly a good welding performance, a certain high temperature strength and resistance to alkaline corrosion, oxidation resistance. Commonly used boiler steel smelting low-carbon steel or electric furnace smelting of low carbon steel, carbon content Wc in 0.16% -0.26% range. Manufacturing high-pressure boiler is the application of pearlitic heat-resistant steel or austenitic heat-resistant steel. In recent years, ordinary low-alloy steel is also used to build boilers, such as 12 manganese, 15 manganese vanadium, 18 manganese molybdenum niobium

15) Stainless steel
   Stainless steel acid-resistant stainless steel referred to as stainless steel, which is composed of stainless steel and acid-resistant steel composed of two parts, in short, can resist atmospheric corrosion of steel called stainless steel, chemical resistance and corrosion resistance of steel called acid-resistant steel. In general, the volume of Wcr containing more than 12% of the steel has a stainless steel on the characteristics of stainless steel by heat treatment after the microstructure can be divided into five categories: namely, ferritic stainless steel, martensitic stainless steel, austenitic stainless steel, Austenitic - ferritic stainless steel and precipitated carbonized stainless steel

16) Heat-resistant steel
   In high temperature conditions, with oxidation resistance and the main enough high temperature strength and good heat resistance of steel is called heat-resistant steel. Heat-resistant steel, including heat-resistant steel and heat-resistant steel two categories. Anti-oxidation steel and can not afford leather. Hot-strength steel refers to steel which has good oxidation resistance at high temperature and has high high-temperature strength. Heat-resistant steel is mainly used for long-term use in high temperature parts