| 摘要 |
A method includes preparing a steel slab in which contents of inhibitor components have been reduced, i.e. content of Al: 100 ppm or less, and contents of N, S and Se: 50 ppm, respectively; subjecting the steel slab to hot rolling and then either a single cold rolling process or two or more cold rolling processes interposing intermediate annealing(s) therebetween to obtain a steel sheet having the final sheet thickness; and subjecting the steel sheet to primary recrystallization annealing and then secondary recrystallization annealing. 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, cooling the steel sheet to a temperature range of 700° C. or lower, and then heating the steel sheet to soaking temperature at the average heating rate not exceeding 40° C./s in a subsequent heating zone. |
| 主权项 |
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. |
