What is steel
Steel is an iron-carbon alloy with a carbon content between 0.04% and 2.3%. In order to make sure its toughness and plasticity are great for use, the carbon content usually does not exceed 1.7%. Apart from iron and carbon element, the main elements of steel include silicon, manganese, sulfur, and phosphorus. There are so many classification methods of steel according to different requirement. And people always talk about cold work mold steel, hot work mold steel, plastic mold steel, high speed steel, alloy steel, carbon steel, free cutting steel, bearing steel and etc. Their information of all types of steel as below.
Cold Work Mold Steel
In fact, the cold work mold steel with a high carbon component. High carbon component will make it satisfy the needs of high hardness and high wear resistance. If toughness needs to be enhanced to improve the impact resistance of dies. Medium carbon steel is a good choice, which can be replaced by hot work mold steel. Adding alloy elements to cold work mold steel to improve the hardenability and the wear resistance. For dies with high requirement on wear resistance, multi-component alloy steel with carbide forming elements like Cr, Mo, W, V and etc is mostly adopted.
Hot Work Mold Steel
Hot work mold steel is great material for making dies for thermal deformation processing of metals. Such as hot- forging dies, hot-extrusion molds, die-casting dies and etc. It is a kind of alloy tool steel. Hot work dies always sustain great impact during the work. Its requirements are really strict. Because they contact with high-temperature metals and suffer repeated heating and cooling during the work. In order to satisfy the working requirements of hot-work dies, hot work die steel need to has the following basic characteristics:
- Good high-temperature strength and good toughness
- Good corrosion resistant performance, higher hardness and adhesion resistance.
- Hot work die steel is not be thermalized under high temperature and has high thermal stability. Otherwise, dies will be prone to plastic deformation.
- The feature of hot work dies is repeated exposure to heat and coldness, so they must have great heat-fatigue resistance.
- Hot work dies are generally large in size. Hot-work mold steel need to have high hardenability to make the mechanical performance of the whole die section uniform.
- The dies accumulate too much heat, the mechanical property would come down. So the hot work mold steel should have good heat conductivity.
- Good forming performance to satisfy the needs of processing and forming.
High speed steel is a tool steel with high hardness, high wear resistance and high heat resistance.
High-speed steel has good processing performance and a good match of strength and toughness. So it is the main material of complex thin blade and impact-resistant metal cutters. As well as high-temperature bearings, cold extrusion dies and etc. High-speed steel produced through smelting. Powder smelted high-speed steel emerged after the 1960s. Its advantage lies in that it can avoid the degradation of mechanical performance and the heat treatment deformation resulted from the carbide segregation during smelting production.
When adding other alloy elements apart from iron and carbon to steel, it would become alloy steel. Adding different elements and use proper processing techniques adopted to it. That will get special features like high strength, high toughness, wear resistance, low-temperature resistance, high-temperature resistance, non- magnetism and etc.
Carbon steel is an iron-carbon alloy with the carbon content of 0.0218%-2.11%. The production and consumption of this kind of steel are huge in every country around the world. It also with a small amount of silicon, manganese, sulfur and phosphorus. The higher carbon content in it, the higher strength it gets, but the plasticity also cut down.
Free Cutting Steel
Free cutting steel is a kind of alloy steel in which adding one or more cutting elements at a certain amount to increase the cutability. Such as sulfur, phosphorus, lead, calcium, selenium, tellurium, and etc. As the cutting process becomes automatic, high-speed and precise. It is very important that steel materials should provide good cutability. The free cutting steel is a great choice for processing on automatic cutting tools.
The bearing steel is the best material of ball bearing, rollers and bearing rings. Bearing steel has a high and uniform hardness and wear resistance, as well as high elastic limits. The fabrication technology of bearing steel is most strict in all of the steel types. Such as the uniformity of the chemical composition of the bearing steel, the content and distribution of non-metallic inclusions, and the distribution of carbides are very strict.
Steel materials are indispensable in the infrastructure construction and the overall economic development of every country, and they are widely used in industry, construction, petrochemical engineering and etc.