| 摘要 |
PROBLEM TO BE SOLVED: To stably manufacture a grain-oriented electrical steel sheet having higher magnetic flux density and low iron loss with AlN as an inhibitor. SOLUTION: The steel plate before final cold rolling contains, by weight %, 0.025-0.10% C, 2.5-4.5% Si, 0.05-0.45% Mn, <=0.04% S and/or Se, 0.015-0.04 Al, <=0.02% N, 0.01-0.20% Cr, 0.003-0.10% P, and has a yield ratio YR (= yield strength YS/tensile strength TS) of 0.7-0.8. Also, in the method for manufacturing the grain-oriented electrical steel sheet, in a cooling process following annealing heating before the final cold rolling, a cooling speed CR in a temperature range from Ar1+50 deg.C to 550 deg.C is controlled by the following formula; log CR ( deg.C/sec)>=5.36-2.36 Mneq(%). Wherein, Mneq=Mn(%)+0.45 Si(%)+1.15 Cr(%)+2.0 P(%).
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