Alloy steel alloy steel in addition to iron, carbon, add other alloy elements, called alloy steel. An iron-carbon alloy formed by adding an appropriate amount of one or more alloying elements on the basis of ordinary carbon steel. According to the different elements added and the appropriate processing technology, high strength, high toughness, wear resistance, corrosion resistance, low temperature resistance, high temperature resistance, non-magnetic and other special properties can be obtained.

The main alloying elements of alloy steel are silicon, manganese, chromium, nickel, molybdenum, tungsten, vanadium, titanium, niobium, zirconium, cobalt, aluminum, copper, boron, rare earth, etc.

Among them, vanadium, titanium, niobium, zirconium, etc. are strong carbide-forming elements in steel. As long as there is enough carbon, under appropriate conditions, they can form their respective carbides. When carbon is lacking or under high temperature conditions, they enter the solid solution in atomic state. Manganese, chromium, tungsten and molybdenum are carbide-forming elements, some of which enter the solid solution in atomic state and the other part forms replacement alloy cementite; aluminum, copper, nickel, cobalt, silicon and the like are elements that do not form carbides and are generally present in a solid solution in an atomic state.

1, according to the content of alloy elements

1) The total content of alloying elements in low alloy steel is less than or equal to 5%;

2) The total content of alloy elements in medium alloy steel is between 5% and 10%;

3) The total content of alloy elements in high alloy steel is greater than or equal to 10%;

2. According to the types of alloy elements

There are chromium steel, manganese steel, chromium manganese steel, chromium nickel steel, chromium nickel molybdenum steel, silicon manganese molybdenum vanadium steel.