| 摘要 |
PURPOSE:To prevent the formation of linear fine grains and to stably obtain the steel sheet by using a continuously cast slab having a specific columnar crystal region as a starting material in a method for producing a steel slab with a specific composition by high temp. heating. CONSTITUTION:A slab of a silicon steel having a composition consisting of, by weight, 0.01-0.2% C, 0.010-0.060% acid-soluble Al, 0.0030-0.0130% N, 0.01-0.06% S, 0.080-0.45% Mn, and the balance Fe, is heated up to >=1250 deg.C, hot-rolled, cold-rolled, and subjected to annealing for decarburization and primary recrystallization. After a separation agent at annealing is applied, finish annealing is done. In this method, a continuously cast slab having, at least from one slab surface, a >=35% columnal crystal region in a thickness direction is used as a starting material. By this method, secondary recrystallization can be done in a superior state and the rate of the generation of linear fine grains can be reduced, and the steel sheet can be produced more stably than heretofore. |
