| 摘要 |
PROBLEM TO BE SOLVED: To improve the magnetic characteristics of a grain oriented silicon steel sheet by measuring the primarily recrystallized structure therein after decarburizing annealing and regulating the decarburizing annealing conditions. SOLUTION: As for this method, as the measuring factors in the primarily recrystallized texture after decarburizing annealing, the ratio of the accumulating degrees of (111) to (411) in the sheet planes is used. In accordance with this ratio, annealing cycles such as the heating temp., soaking temp. or the like are regulated. The steel sheet in which the primarily recrystallized texture has been regulated as the above, is thereafter subjected to nitriding treatment to suppress the growth of the grains, and the texture is frozened till secondary recrystallization. As to the content of N after the nitriding treatment, comparing to the content of Al in the steel, the weight ratio of N/Al shall be regulated to 0.5 for allowing secondary recrystallization to stably occur. After that, finish annealing is executed to preferentially grow the grains in the (110)(001) orientation by the secondary recrystallization. |
