ferroalloys

Ferroalloys, which are alloys of iron (less than 50 percent) and one or more other metals, are important as a source of various metallic elements in the production of alloy steels. The chief ferroalloys are ferromanganese, ferrochromium, ferromolybdenum, ferrotitanium, ferrovanadium, ferrosilicon, ferroboron, and ferrophosphorus. Although these ferroalloys are brittle and unsuitable for direct use in fabricating products, they are a useful source of these elements for the alloy steels, and are used in all steels-e.g., plain carbon, stainless, alloy, electrical, tool, etc. They are prepared from charges of the nonferrous metal ore, iron or iron ore, coke or coal, and flux by treatment at high temperature in submerged-arc electric furnaces. An aluminothermic reduction process is employed for making ferrovanadium, ferrotitanium, and ferroniobium (ferrocolumbium). Because ferroalloys usually have lower melting ranges than do the pure elements, they can be incorporated more readily in the molten steel to achieve a specified chemical composition and provide properties required to make particular products.