GB203728A - Alloys - Google Patents

Abstract

203,728. Saltrick, W. R. March 17, 1922. Alloys. - Refined low-carbon and low-silicon alloys of iron with chromium or tungsten or both, including ferro-chrome, stainless or rustless steels or irons, and high-speed steels, are made by reducing in an electric or other furnace a charge containing a reducible compound, such as chromite, and a silicon-containing reducing-agent, with or without subsequent alloying of the product with iron, the alloy in either case being refined by further heating with refining-agents comprising a reducible oxygen-containing compound or one or more constituent metals of the alloy. The reducing-agent may include some aluminium. The furnace lining and the electrodes are such as not to add carbon to the alloy. The process may be carried out by reducing a charge comprising a silicon-containing reducing-agent, chromite, and a more readily reducible compound such as an oxide or ore of iron or other metal, an oxide of chromium, or a chromate, bichromate, or other salt, the chromite and the iron oxide &c. being employed in such excess as to produce an alloy low in carbon and silicon. Fluxes such as lime and fluorspar may be used. The refining operation may be effected by melting the impure alloy and the refining-agents together; or the refining-agents may be employed as constituents of a refining slag; or the molten impure alloy may be poured through a heated bed or column containing the reagents; or the reducible charge and the refining-agents may be contained in separate compartments of one furnace; and in some cases the refining-agents may be briquetted. A gaseous refining-blast may also be applied either before or after the refining-operations described above. Specifications 192,150, 201,589, 202,336, 202,664, and 203,357 are referred to.