NON-ORIENTED ELECTRIC-GRADE SHEET STEEL WITH SUPERIOR MAGNETIC PROPERTIES IN ROLLING DIRECTION, AND

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FIELD : metallurgy, in particular, non-oriented electric-grade sheet steel used as iron core material in electrical equipment, and process for producing of said steel. SUBSTANCE : non-oriented electric-grade sheet steel contains, wt% : Si in an amount of 2.0 or less; Mn 3.0 or less; Al 1.0-3.0; at least one of elements : Sn, Sb, Cu, Ni, Cr, P; rare-earth elements; Ca and Mg total of from 0.002 to 0.5; Fe the balance, and unavoidable mixtures. Said steel has ratio (B50L/Bs) of density of magnetic flux B50L in rolling direction after annealing process for removal of residual stress to density of saturated magnetic flux Bs making 0.85 or higher, and losses in core W15/50L 2.0 W/kg or less. Method involves hot rolling; annealing; etching treatment; two or more cooling rolling operations with reduction extent of from 60 to 75% with intermediate and final annealing at temperature of 800-1, 100 C during 30 s; killing with reduction extent of 3-10% and annealing for stress removal. Method allows sheet steel to be produced which has crystal grain size of 50 micron or less. EFFECT : increased efficiency of method and improved quality of non-oriented electric-grade sheet steel. 12 cl, 5 tbl, 3 ex