METHOD FOR PRODUCTION OF COLD-ROLLED ISOTROPIC ELECTRICAL-SHEET STEEL Russian patent published in 2003 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: the method for production of cold-rolled isotropic electrical-sheet steel consists in melting, hot rolling, pickling, cold rolling and thermal treatment, the temperature of process annealing in the process of thermal treatment of cold-rolled steel with content, percent by mass: carbon not more than 0.04; phosphorus within 0.20 to 0.40; silicon not more than 0.20; manganese not more than 0.40; aluminum not more than 0.20; sulfur not more than 0.0115; the rest iron and inevitable impurities are determined depending on the content of phosphorus and the thickness of cold-rolled metal in accordance with relation: tp=K₁(K₂+P,[%])= +-20C, where temperature of process annealing, C; K₁, K₂ - experimentally determined coefficients; K₁= 730, [C/%] , K₂ - 1.0[%] - at H< 0.60 mm, K₂= 1.03[%] - at H> 0.60 mm, P-content of phosphorus in steel, percent by mass; H-thickness of cold-rolled strips, mm. EFFECT: enhanced degree of isotropism in the specific magnetic loss and the level of electromagnetic induction of cold-rolled isotropic electrical sheet steel. 2 tbl, 2 ex