| 摘要 |
PROBLEM TO BE SOLVED: To produce a high magnetic flux density grain-oriented silicon steel sheet small in the dispersion of magnetic properties in the width direction by executing annealing before final intensive cold rolling for a continuously cast slab having a specified compsn. composed of C, Si, Mn, Al N, S, Se and Fe under specified conditions. SOLUTION: A continuously cast slab contg., by weight, 0.015 to 0.100% C, 2,0 to 4.0% Si, 0.03 to 0.12% Mn, 0.010 to 0.065% Sol.Al, 0.0040 to 0.0100% N and one or more kinds of S and Se by 0.005 to 0.050%, and the balance substantially Fe is heated, is thereafter subjected to hot rolling, is subjected to hot rolled sheet annealing and is subjected to final intensive cold rolling, or, before the final intensive cold rolling, prelimary cold rolling and precipitation annealing are executed. After that, its sheet thickness is regulated to a final one, and decarburizing-primary recrystallization annealing and final finish annealing are executed. At this time, as for the annealing before the final intensive cold rolling, it is held at 800 to 1200 deg.C, and after that, cooling to 400 deg.C is executed in such a manner that the center part in the width direction is cooled at a cooling rate of 20 to 120 deg.C/s and the edge parts are cooled at a cooling rate of >=10 deg.C/s and also slower than in the center part. |
