Ferroalloy

ferroalloy

Alloy of iron (less than 50%) and one or more other metals, important as a source of various metallic elements in the production of alloy steels. The principal ferroalloys are ferromanganese, ferrochromium, ferromolybdenum, ferrotitanium, ferrovanadium, ferrosilicon, ferroboron, and ferrophosphorus. They usually have lower melting ranges than do the pure elements and can be incorporated more readily in the molten steel. Ferroalloys 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.

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ferroalloy [¦fe·rō′al‚ȯi]

(metallurgy)

Any alloy containing iron, usually in major amount. Also known as ferrous alloy.

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Ferroalloy 

any of the intermediate metallurgical products that are alloys of iron with silicon, manganese, chromium, and other elements and that are used in the smelting of steel (for deoxidizing and alloying the molten metal, binding harmful impurities, imparting the desired structure and properties to the metal), as well as in the manufacture of other ferroalloys (converted ferroalloys). By convention, the ferroalloy group also includes certain alloys, such as silicomanganese and calcium-silicon, which contain iron only as an impurity and certain metals and nonmetals in technically pure form (metallic manganese, metallic chromium, crystalline silicon). Ferroalloys containing several components are described as complex.

With iron present, the reduction of the oxides of the critical element of the ferroalloy (Mn, Cr) by carbon occurs at a lower temperature, more rapidly, more completely, and with less expenditure of energy. The melting range of ferroalloys, with rare exceptions, is lower than that of the pure metal; this difference facilitates the ferroalloy’s dissolution in the molten steel and cuts down the losses of the critical element caused by oxidation. The cost of an element in a ferroalloy is lower than in the technically pure form. The content of ferroalloy components that is considered standard varies with the chemical composition of the raw materials and the conditions under which the ferroalloys are smelted and introduced into the molten steel.

V. A. BOGOLIUBOV