| 摘要 |
PURPOSE:To produce an extra thin grain-oriented silicon steel sheet having high magnetic flux density at a low cost by forming a cast thin slab prepared by applying rapid solidification to a molten silicon steel containing specific amounts of Si to a specific sheet thickness of final product by means of cold rolling at a specific final cold draft. CONSTITUTION:A molten silicon steel containing 2.5-4.5% Si and other required components, such as inhibitor components, is subjected to continuous rapid solidification so as to be formed into a cast thin slab. After annealed at about 950-1200 deg.C for about 30sec-30min, the cast thin slab is cold-rolled once or is cold-rolled twice or more while process-annealed between the cold rolling stages so that final cold rolling draft is regulated to >=80%, preferably >= about 90%, until a final product sheet thickness of <=150mum is reached. By the above cold rolling at high draft, secondary recrystallized grains having extremely high degree of Goss integration are obtained. This cold rolled sheet is subjected to decarburizing annealing and to finish annealing, by which the extra thin grain-oriented silicon steel sheet having extremely high magnetic flux density can be obtained while obviating the necessity of hot rolling. |
