Patent ID: 9574249
Date: 2017-02-21
CPC Classifications: C21D,C22C,H01F

Claim:
1. A method for manufacturing a grain oriented electrical steel sheet, comprising the steps of: preparing a steel slab having a composition including C: 0.08 mass % or less, Si: 2.0 mass % to 8.0 mass %, Mn: 0.005 mass % to 1.0 mass %, Al: 100 ppm or less, N, S and Se: 50 ppm or less, respectively, and balance as Fe and incidental impurities; rolling the steel slab to obtain a steel sheet having the final sheet thickness; and subjecting the steel sheet to primary recrystallization annealing and then secondary recrystallization annealing, wherein Al, N, S and Se constitute inhibitor components to be reduced, and the primary recrystallization annealing includes heating the steel sheet to temperature equal to or higher than 700° C. at a heating rate of at least 150° C./s, then cooling the steel sheet only to a temperature within the range of 500° C. or more and 700° C. or lower, then heating the steel sheet to soaking temperature at an average heating rate not exceeding 40° C./s, and then cooling the steel sheet.