Non-oriented electrical steel sheet with excellent magnetic properties in the rolling direction and manufacturing method thereof

摘要

Non-oriented electrical steel sheet remarkably improved in magnetic properties in the rolling direction by a method superior in cost and productivity, that is, non-oriented electrical steel sheet excellent in magnetic properties in the rolling direction comprising, by wt %, Si in an amount of 2.0% or less, Mn in 3.0% or less, Al in 1.0% to 3.0%, at least one of Sn, Sb, Cu, Ni, Cr, P, REM, Ca, and Mg in a total of 0.002% to 0.5%, and a balance of Fe and unavoidable impurities and having a ratio (B50L/Bs) of the magnetic flux density B50L in the rolling direction after stress relief annealing and a saturated magnetic flux density Bs of 0.85 or more and an core loss W15/50L of 2.0 W/kg or less, produced by the method of annealing the hot band at 800° C. to 1100° C. for 30 seconds or more to achieve a crystal grain size after final annealing of 50 mum or less, skin pass rolling the sheet by a reduction of 3% to 10%, then stress relief annealing it. Further, a cold rolling reduction of 60% to 75% is preferable.