| 摘要 |
PURPOSE: To produce a grain-oriented silicon steel sheet excellent in magnetic properties at a low cost by subjecting a silicon steel slab having a specified compsn. to hot rolling, cold rolling, nitriding treatment or the like in succession under specified conditions. CONSTITUTION: As for a silicon steel stab having a compsn. contg., by weight,<=0.020% C, 2.0 to 4.5% Si, 0.010 to 0.08O% acid soluble Al, 0.001 to 0.020% N, 0.005 to 0.15% Bi, 0.0080 to 0.040% of one or more kinds of S and Si, 0.01 to 1% Cu and 0.01 to 0.5% Mn, furthermore contg. one or more kinds among 0.001 to 0.15% P, 0.001 to 0.3% Sn, 0.001 to 0.15% Sb, 0.001 to 0.15% Pb and 0.0010 to 0.l% B, and the balance Fe, rough rolling is started in the temp. range of 1000 to 1200 deg.C, and finish rolling is executed. Next, the cold rolled sheet in which the cold rolling rate before primary recrystallization annealing is regulated to 75 to 95% is heated at 850 to 1000 deg.C for 1 to 300 sec, and after the total nitrogen content is regulated to be in the range of 50 to 200ppm it necessary, it is coated with a separation agent for annealing and is subjected to finish annealing. |
