| 摘要 |
PROBLEM TO BE SOLVED: To stably obtain the subject steel sheet having a magnetic domain controlling effect free from dissipation even after stress relief annealing by forming linear grooves in the surface of a steel sheet before final cold rolling, oxidizing the sheet surface by annealing, applying cold rolling, and introducing oxides into the vicinity of the sheet surface. SOLUTION: A slab, having a composition consisting of, by weight, 0.03-0.10% C, 2.5-4.5% Si, 0.02-0.15% Mn, 0.01-0.05% S, 0.01-0.04% sol.Al, 0.003-0.015% N, and the balance iron, is hot-rolled and precipitation-annealed. The resultant plate is cold-rolled once or cold-rolled two or more times, while process-annealed between cold rolling stages, at >=50% final cold rolling draft, and the resultant sheet is subjected to decarburizing and finish annealing, by which the grain oriented silicon steel sheet is obtained. At this time, linear grooves are formed in the surface of the steel sheet under the condition of equation before the annealing stage in the course between hot rolling and final cold rolling and oxides are formed in the bottoms of the grooves by successive annealing, and the depth in the steel sheet and the width of the linear oxides in the final product are regulated to 3-30μm and 10-100μm, respectively, and also the spaces in a rolling direction are regulated to 1-10mm. in the equation, (α) and (β) represent the angle, formed by the direction perpendicular to rolling direction and the linear grooves, just after groove formation and after final cold rolling, respectively, and 0 deg.<=β<=30 deg. is satisfied, and further, t0 and t1 represent the sheet thickness just after groove formation and that after final cold rolling, respectively. |
