| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably produce a thin grain oriented silicon steel sheet having extremely high magnetic flux density by applying, after degreasing, specific decarburizing annealing to a cold rolled sheet of silicon steel containing Al and N for grain oriented silicon steel sheet and controlling picking loss. SOLUTION: A silicon steel slab for grain oriented silicon steel sheet, containing Al and N as inhibitor components and having a composition containing, e.g. 0.03-0.09% C, 2.0-4.5% Si, 0.05-0.15% Mn, 0.01-0.04% Al, and about 0.004-0.012% N, is used as a stock. After hot rolling, final cold rolled sheet thickness is regulated to <=0.20mm by means of two or more times of cold rolling including process annealing. After degreasing, decarburizing annealing is applied, and then, after the application of a separation agent at annealing, final finish annealing is performed. At the time of producing this thin grain oriented silicon steel sheet, the average temp. raise rate between 400 and 800 deg.C at the decarburizing annealing is regulated to (5 to 25) deg.C/s and also decarburizing annealing conditions are regulated, and, at the time of successive pickling, pickling loss, under the pickling conditions of, e.g. 5% HCl, 60 deg.C, and 60sec, is controlled to (0.1 to 0.4)g/m<2> .</p> |
