Ferromolybdenum is an alloy of molybdenum and iron. Its main use is as an additive for molybdenum in steelmaking, with the added amount of molybdenum ranging from 50% to 70%. Adding molybdenum to 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, together with other alloying elements, 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 is added to cast iron to increase its strength and wear resistance.