| 摘要 |
PURPOSE:To stably obtain the grain-oriented silicon steel sheet by heating a silicon steel slab with the prescribed composition at high temp., applying annealing and quenching to the above between hot rolling and final cold rolling stages, subjecting the resulting sheet to final cold rolling, and then carrying out treatment, such as decarburizing annealing in a wet atmosphere. CONSTITUTION:A silicon steel slab having a composition represented by the right-hand description by weight percentage is heated at a high temp. in the vicinity of about 1,400 deg.C and subjected to hot rolling in which rolling of >=20% draft is performed six times or more in its finish rolling. Annealing is applied to the above once or more at 1,030-1,200 deg.C for <=10min between the above hot rolling and final cold rolling stages, followed by quenching by means, e.g., of immersion into 100 deg.C hot water. Subsequently, the above rolled steel sheet is subjected to final cold rolling at 81-95% draft, and, in the course of this final cold rolling, the sheet is held three times or more at 150-300 deg.C for >=30sec. Then, the resulting steel sheet of 0.05-0.25mm final sheet thickness is subjected to decarburizing annealing in a wet atmosphere and a separation agent at annealing composed principally of Mg is applied to this sheet, and further, high-temp. finish annealing is carried out, by which the desired thin grain-oriented silicon steel sheet having high magnetic flux density and excellent in iron loss can be obtained. |
