METHOD OF PRODUCING ROLLER-BEARING STEEL Russian patent published in 1997 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: method includes smelting and oxidizing metal in arc furnace, tapping metal into ladle, treatment with basic slag, alloying and deoxidation with silicon-containing materials and aluminum, and blowoff with argon. According to invention, metal is additionally subjected to vacuum-slag treatment; into ladle, non-deoxidized metal without slag is tapped; treatment with basic slag is performed when metal is tapped from furnace and finished in ladle; and argon blowoff is performed during vacuum-slag treatment with intensity 0.001-0.010 cu.m/min per 1 t of metal. In the stage of basic slag treatment, first, slag with basicity B=CaO/SiO₂= 2.0-6.0 and content FeO+MnO=K=1-5 wt % is used until sulfur content 0.008-0.012 wt % is attained, whereas B/K ratio is maintained in the range 1 to 3. Then, before vacuum-slag treatment, basicity of slag is reduced to 1.0-1.5, and vacuum-slag treatment is carried out under agitation by argon with intensity (I) determined from formula: JM²=0.40-0.53 where I is expressed in cu. m/min per 1 t of metal and M is weight of slag-forming components added into ladle during tapping of metal out of furnace and finishing, kg/t. EFFECT: enhanced efficiency of process. 1 tbl