An ferro alloy composed of molybdenum and iron, generally containing 50-60% molybdenum, is used as an alloy additive for steelmaking. Ferromolybdenum is an alloy of molybdenum and iron. Its main purpose is as an additive of molybdenum in steelmaking. The addition of molybdenum to the steel can make the steel have a uniform fine-grained structure, improve the hardenability of the steel, and help eliminate temper brittleness. In high-speed steel, molybdenum can replace part of tungsten. Molybdenum is used in combination with other alloying elements to produce stainless steel, heat-resistant steel, acid-resistant steel and tool steel, as well as alloys with special physical properties. Molybdenum can be added to cast iron to increase its strength and wear resistance.