| 摘要 |
PURPOSE:To manufacture the title steel sheet by subjecting a hot rolled steel sheet contg. specific ratios of C, Si, Al, P and Mn to cold rolling and executing annealing and cooling thereto under specific conditions. CONSTITUTION:A hot rolled steel sheet contg., by weight, <=0.020% C, <=2.0% Si, <=0.6% Al, <=0.1% P, <=1.5% Mn and the balance substantial Fe is subjected to cold rolling. The heating speed is then regulated to >=200 deg.C/min and the steel sheet is annealed at the Ac3 transformation point or above for >=15sec; after that, it is cooled at the speed of >=10 deg.C/min. If required, the steel sheet is furthermore annealed in the temp. range of about >=700 deg.C for about >=1min. By this method, the nonoriented electrical steel sheet having excellent magnetic characteristics in the direction of circumference can advantageously be manufactured without the particular limitation of draft and the sheet thickness in hot rolling. |
