Patent ID: 6613160
Filing Date: 2003-09-02
Classification: C21D,C22C,C23C,Y02P

Abstract:
A method to produce a grain-oriented electrical steel sheet having a high magnetic flux density by heating a silicon steel, comprising, in mass %,0.8 to 4.8% of Si, 0.085% or less of C, 0.01 to 0.065% of Sol. Al and 0.012% or less of N, with the balance consisting of Fe and unavoidable impurities, to a heating temperature of 1,280Â° C. or below, hot-rolling the heated silicon steel into a steel sheet, cold-rolling the steel sheet in one cold rolling step or two or more cold rolling steps with an intermediate annealing in between to a final thickness, annealing the cold-rolled sheet for decarburization, applying an annealing separator composed mainly of magnesia, and then conducting finish annealing, in this sequential order, characterized by: controlling the ratio I{111}/I{411} in the texture after the decarburization annealing so as not to exceed 3.0; controlling the oxygen content of an oxide layer of the decarburization annealed steel sheet so as not to exceed 2.3 g/m2; and after decarburization annealing, nitriding the steel sheet.