| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a grain oriented silicon steel sheet having excellent iron loss characteristic. SOLUTION: A hot rolled plate of a grain oriented silicon steel, having a composition consisting of, by weight, <=0.10% C, 2.5-7.0% Si, ordinary inhibitor components, and the balance Fe with inevitable impurities, is cold-rolled once or cold-rolled two or more times while process-annealed between cold rolling stages after hot rolled plate annealing or is cold-rolled two or more times while process-annealed between cold rolling stages without hot rolled plate annealing. The resultant cold rolled sheet is subjected to decarburizing annealing and to final finish annealing, by which the grain oriented silicon steel sheet is manufactured. In this method, a strip, rolled to final sheet thickness, is subjected, prior to decarburizing annealing, to rapid heating treatment up to 800 to 950 deg.C at >=100 deg.C/s heating rate at <=500 ppm atmospheric oxygen concentration and then to decarburizing annealing while regulating the temp. in the front region in the decarburizing stage to 775 to 840 deg.C lower than the ultimate temp. at the rapid heating and also regulating the temp. in the rear region to 815 to 875 deg.C higher than the temp. in the front region. |
