Molybdenum iron is composed of molybdenum and iron, generally containing 50~60% molybdenum, which is used as alloy additive for steelmaking. Ferromolybdenum is an alloy of molybdenum and iron. It is mainly applied as an additive of molybdenum in steelmaking. The addition of molybdenum in steel can make the steel have uniform fine-grained structure, improve the hardenability of steel, and help to eliminate temper embrittlement. In high-speed steel, molybdenum can replace a part of tungsten. Together with other alloy elements, molybdenum is widely used in the production of stainless steel, heat-resistant steel, acid-resistant steel and tool steel, as well as alloys with special physical properties. Molybdenum added to cast iron can increase its strength and wear resistance.