| 摘要 |
PURPOSE:To manufacture electrical sheet free from embrittlement and having good magnetic characteristic after stress relief annealing, by hot rolling low C steel contg. specified quantities of Mn, Al, B and regulated quantities of P, N under a specified condition punching and stress relief annealing the sheet after cold rolling contg. skin pass rolling. CONSTITUTION:Slab composed of, by weight <=0.020% C, <=1.0% Si, 0.75-0.50%Mn, <0.050% P, <=0.10% Al, <=0.0070% N, 0.0003-0.0100% B as solid soln. B indicated by B-0.7N% and the balance Fe with inevitable impurity is prepd. The slab is hot rolled at >=900 deg.C finish rolling temp. and >=800 deg.C winding up temp. and wound, annealed by the heat held thereby. Next, cold rolling at one time of >=2 times contg. skin pass rolling interposing intermediate annealing are applied. The sheet is punched, stress relief annealed as it is or after finish annealing. Nonoriented electrical sheet obtd. by the method can be worked to a prescribed electrical instrument without causing crack, etc.
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