| 摘要 |
PURPOSE:To provide a grain-oriented silicon steel sheet having superior magnetic characteristics by subjecting a cold rolled silicon steel sheet having specified C and Si contents to primary heat treatment at a specified temp. for a specified holding time and secondary heat treatment at a specified heating rate and specified temp. in a decarburization annealing stage. CONSTITUTION:A hot rolled silicon steel sheet contg. 0.010-0.080wt% C and 2.5-4.0wt% Si is cold rolled to the final thickness. Cold rolling may be carried out twice or more with a process annealing stage in-between. The cold rolled steel sheet is subjected to decarburization annealing by primary heat treatment at 450-570 deg.C for 10sec-5hr, preferably 10sec-5min holding time, optional cooling and secondary heat treatment composed of heating to 750 deg.C at >=10 deg.C/sec, preferably >=20 deg.C/sec heating rate and soaking at 750-950 deg.C. Final finish annealing is then carried out. Thus, a grain-oriented silicon steel sheet having superior magnetic characteristics can be manufactured.
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