Patent ID: 8236110

Claim:
A method of producing a grain-oriented electrical steel sheet comprising: heating a slab containing, in mass %, C: 0.025 to 0.10%, Si: 2.5 to 4.5%, Mn: 0.03 to 0.55%, and Al: 0.007 to 0.040% to 1,100 to 1,450° C. or greater; hot rolling the slab to obtain a hot-rolled sheet; annealing the hot-rolled sheet; cold rolling the annealed sheet multiple times with a split-housing reversible cluster rolling mill; and subjecting the cold-rolled sheet to primary recrystallization annealing followed by secondary recrystallization annealing, in which method of producing a grain-oriented electrical steel sheet: (a) a first cold rolling or first and second cold rollings are performed using a work roll of 55 mm to less than 105 mm diameter; (b) a second or third cold rolling to a penultimate cold rolling are performed using a work roll of 105 mm to less than 150 mm diameter; and (c) a final cold rolling is conducted using a work roll of a diameter smaller than the diameter of the work roll in the cold rolling of (b).