| 摘要 |
PROBLEM TO BE SOLVED: To obtain a stable magnetic characteristic in the whole length of a coil without positively applying nitriding on the way of process by controlling annealing speed of a decarburize-annealing by dividing the temperature into two specific temp. ranges to a silicon steel slab containing C, Si, Mn, soluble Al, N, and Se and S in the range satisfying a specific relation of Se and S. SOLUTION: The silicon steel slab contains, by wt.%, 0.005-0.08% C, 2.0-4.5% Si, 0.03-2.5% Mn, 0.005-0.030% soluble Al and 0.003-0.010% N, and Se and S in the range satisfying Se+2.47S <=0.035%. In the case of using (u) ( deg.C/sec) for heat-up speed in the range of 600-750 deg.C on the way of the heat-up process in the decarburize-annealing and (v) ( deg.C/sec) for heat-up speed from 750 deg.C to the temp. at lower by 10 deg.C than the soaking temp., the (u) and the (v) are made to satisfy three conditions, i.e., 2<=u, 0<=v<=15, 1.5u-30<=v. After last finish annealing, if necessary, insulating coating application and burning, further flatening annealing are executed to make a product. |
