Rich Types and Excellent Properties of Alloy Steel
Alloy steel is a composite material that adds one or more other alloying elements to carbon steel. The different alloying elements give it a rich variety and excellent properties. This gives alloy steel a wider range of uses, provides a broad space for material selection, and is favored in various fields, making it play an important role in automobile manufacturing, aerospace, machinery, construction, shipbuilding and other fields. Therefore, this article will take you to learn more about the types and properties of alloy steel.
Alloy Steel Types
Alloy steel can be divided into many types according to the added alloying elements, content and uses. Some common types of alloy steel include:
- Classification according to the content of alloy elements
(1) Low alloy steel: This steel has a small amount of alloy elements, the total alloy content is less than 5%, and its strength and wear resistance are higher than ordinary carbon steel. It is usually delivered in a hot-rolled state. Common low alloy steels include 20Cr, 40Cr, Q345, 42CrMo, 12CrMo, 30CrMnSiA, 4140, 4340, 8620, etc.
(2) Medium alloy steel: It contains 5~10% of the total alloy content. Medium alloy steel mainly includes 20CrNi2Mo, Cr8, etc.
(3)High alloy steel: It is a material containing a large number of alloy elements, with the total alloy element content being greater than or equal to 10%. It is widely used in high-tech fields such as aerospace, petrochemicals, energy, automobiles, etc. The grades of high alloy steel include: 23Co14Ni12Cr3MoE, Cr12, SKD 11, etc.
2.Classification by alloy elements
Alloy steel can be divided into chromium steel, manganese steel, boron steel, chromium-manganese steel, silicon-manganese steel, chromium-nickel steel, chromium-nickel-molybdenum steel, silicon-manganese-molybdenum-vanadium steel, etc.
Classification according to use
(1) Steel for building structures
(2) Steel for mechanical structure
(3) Alloy tool steel
(4) Bearing steel
(5) Alloy spring steel
(6) Alloy mold steel
(7) Special performance steelOther or special types
Cast alloy steel
High strength low alloy steel
Advanced high-strength steel
Rolling bearing alloy steel
Wear-resistant alloy steel
High temperature resistant alloy steel
Maraging steel
Alloy quenched and tempered steel
Alloy Steel Properties
Alloy steel can have many excellent properties by adding a certain amount of elements and adopting appropriate processing techniques. The following are common properties of alloy steel:
1.Strength and hardness: Alloy steel usually has higher strength and hardness than ordinary carbon steel. The presence of alloy elements, especially tungsten alloy, forms tungsten carbide with carbon and can form strong bonds in the lattice structure, improve the strength and hardness of steel.
2.Corrosion resistance: Some alloy steels also contain a small amount of chromium, which can form a corrosion-resistant oxide film to prevent further oxidation reactions, giving them excellent corrosion resistance and oxidation resistance. And when more than 12% of nickel alloy is added, it provides excellent corrosion resistance. There are also combinations of silicon and molybdenum, tungsten, chromium, etc., which can also improve corrosion resistance and oxidation resistance.
3.Heat resistance: Due to the addition of high-temperature alloy elements, such as tungsten, molybdenum, etc., it can improve its heat resistance and thermal expansion resistance. It has a higher melting point and is suitable for working in high-temperature environments, giving alloy steel good thermal stability.
4.Toughness: Nickel, vanadium, copper, and aluminum elements in alloy steel can refine the structure grains and improve its toughness, and it can resist external impact and vibration and is not easy to break.
5.Hardenability: Generally, the hardenability of alloy steel is better than that of carbon steel. Some alloy steels add appropriate amounts of vanadium, molybdenum, silicon, boron, chromium, manganese and other alloying elements to improve the hardenability and make these alloys When steel is quenched, the required hardness depth can be achieved from the surface to the core, and the hardness can be distributed evenly.
6.Processing performance: Alloy steel has good machinability, among which sulfur element can improve the cutting processability, and bismuth element and lead element can improve the machining performance.
In addition to the above properties, some alloy steels also have high wear resistance, high red hardness, thermal strength, good plasticity, etc.
All in all, the rich types and excellent properties of alloy steel meet the needs of many fields and play an important role, its development and application prospects are very broad. Therefore, our Songshun Steel will continue to develop and advance in the future, able to provide higher quality and high-performance alloy steel material, bringing more possibilities to customers.
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