| 摘要 |
PROBLEM TO BE SOLVED: To provide a means for manufacturing a grain-oriented electromagnetic steel sheet with mirror surface, superior in magnetic properties and surface smoothness, while adequately decarburizing the steel material in a decarburization annealing step. SOLUTION: The method for manufacturing the grain-oriented electromagnetic steel sheet with the mirror surface superior in core loss, comprising cold rolling a hot-rolled silicon steel sheet, which includes, by mass%, 2.0-4.0% Si, 0.01-0.05% acid- soluble Al, 0.01% or less N, 0.3% or less Mn, 0.05% or less S, and the balance substantially Fe with unavoidable impurities, once or more times while sandwiching intermediate annealing, into a final sheet thickness, and employing alumina as a main component in an annealing separating agent between the sheets, when laminating the steel sheets after decarburization annealing, to make the surface to be a mirror plane after finish- annealing, is characterized by separating the decarburization annealing process into the former step and the latter step, and performing the annealing in such oxidation degree (PH2 O/PH2 ) ranges of the former step P1 and the latter step P2, as to satisfy expressions of: 0.05<=P1<=0.2 and P2<=P1-0.03. |
