MANUFACTURING METHOD OF GRAIN-ORIENTED ELECTRICAL STEEL SHEET

摘要

A slab having a desired composition containing Sn: 0.02% to 0.20% and P: 0.010% to 0.080% is used. A finishing temperature of hot rolling is 950° C. or lower, hot-rolled sheet annealing is performed at 800° C. to 1200° C., a cooling rate from 750° C. to 300° C. in the hot-rolled sheet annealing is 10° C./second to 300° C./second, and a reduction ratio of cold rolling is 85% or more. A nitridation treatment in which an N content of a decarburization-annealed steel sheet is increased is performed between beginning of decarburization annealing and occurrence of secondary recrystallization in finish annealing.