METHOD OF PRODUCTION OF BEARING STEEL Russian patent published in 2003 - IPC

FIELD: ferrous metallurgy; particularly, melting and off-furnace treatment of bearing steel. SUBSTANCE: method of production of bearing steel incorporates steps of melting semifinished product in steelmaking unit, pouring melt into ladle, supply of alloying additions and deoxidizing agents to ladle, refining melt up to necessary chemical composition, vacuum degassing in ladle, as well as stirring melt in ladle. While tapping simifinished product with temperature within the range from 1620 C to 1660 C, ferrochromium at consumption of 1.8-2.1 kg/t of melt and ferromanganese at consumption of 0.28-0.35 kg/t of melt are supplied to ladle; deoxidizing agent is supplied to generated slag in ladle at consumption of 0.1-0.3 kg/t of melt, melt is heated in ladle-furnace up to 1590-1620 C temperature. Then melt is subject to vacuum degassing in ladle at residual pressure of not more than 0.5 mm MC within 20-30 minutes; ferrosilicon is added to ladle with silicon content within the range of 45-75 mass % at consumption of 3.3-5.5 kg/t of melt, then alloying of melt by aluminum takes place by means of supply of aluminum wire to ladle at consumption of 0.25-0.35 kg/t of melt and once more melt is subject to vacuum degassing in ladle at residual pressure of not more than 0.5 mm MC within 10-20 minutes. EFFECT: reduced content of non-metallic inclusions in bearing steel and regulation of phase composition of oxides, sulfides and globules. 1 tbl, 1 ex