| 摘要 |
PROBLEM TO BE SOLVED: To inhibit iron loss deterioration due to unstable secondary recrystallization arising at a coil end in final annealing of a grain oriented magnetic steel sheet having a sheet thickness of 0.12 to 0.25 mm.SOLUTION: A production method of a grain oriented magnetic steel sheet having a sheet thickness of 0.12 to 0.25 mm includes: heating at a temperature of 1,250°C or more, a steel slab containing C:0.04 to 0.12 mass%, Si:1.5 to 5.0 mass%, Mn:0.01 to 1.0 mass%, one or two kind selected from S and Se:0.005 to 0.05 mass% in total, sol.Al:0.010 to 0.027 mass%, N:0.0040 to 0.0110 mass%, sol.Al/N:1.50 to 2.50, B:1.2 mass ppm or less and the balance Fe with inevitable impurities; then performing hot rolling; performing cold rolling one time or 2 or more times with intermediate rolling interposed between them to obtain a cold rolled sheet having a final sheet thickness; performing primary recrystallization annealing, performing final annealing and further performing flattening annealing. |
