Alloy steel, alloy steel is also called special steel. An appropriate amount of one or several alloying elements is added to the carbon steel to change the structure of the steel, so that the steel has various special properties, such as high strength, hardness, good plasticity, toughness, wear resistance, resistance corrosion, and many other good properties. The following are the properties and uses of some special steels:

Tungsten steel, manganese steel: very hard, making metal processing tools, tractor tracks and axles, etc.

Manganese silicon steel: particularly strong in toughness, making spring sheets, spring coils, etc.

Molybdenum steel: high temperature resistance to manufacture aircraft crankshafts, particularly hard tools, etc.

Tungsten-chromium steel: high hardness, strong toughness, used for machine tools and molds, etc.

Nickel-chromium steel (stainless steel): strong corrosion resistance, not easy to oxidize. Manufacture of acid-resistant towers, medical equipment and daily necessities in chemical production.