Method for producing a grain-oriented electrical steel sheet having a mirror surface and improved core loss

摘要

Disclosed is a method for producing a grain-oriented electrical steel sheet having mirror surface containing 0.8 to 4.8% of Si in the form of a strip which has been subjected to a conventional series of operations including hot rolling with or without annealing, cold rolling once or at least twice with intermediate annealing to obtain a final thickness, decarburization annealing with or without nitriding treatment, coating the steel sheet with an annealing separator mainly containing non-hydrating oxide and final annealing, the improvement comprising: satisfying the relationship <MATH> where ÄAÜ is the total concentration of alkali metal impurity in the annealing separator (weight %), and ÄOÜ is the amount of oxygen contained in the steel sheet just prior to the final annealing (g/m<2>). <IMAGE>