NON-ORIENTED ELECTRIC-GRADE SHEET STEEL WITH SUPERIOR MAGNETIC PROPERTIES IN ROLLING DIRECTION, AND METHOD OF PRODUCING THE SAME Russian patent published in 2008 - IPC C21D8/12 

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 (B50_L/Bs) of density of magnetic flux B50_L 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 W15/50_L 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