| 摘要 |
PURPOSE:To obtain a grain oriented silicon steel sheet having high magnetic flux density and low iron loss by hot-rolling a silicon steel slab of a specific composition and applying cold-rolling inserting annealing without executing hot-rolled sheet annealing, heat-decarburizing, nitriding and finish-annealing. CONSTITUTION:The composition of the silicon steel is made to be, by wt.%, 0.005-0.025 C, 2.0-4.5 Si, 0.010-0.080 acid-soluble Al, 0.001-0.020 N, 0.0020-0.060 S, 0.005-0.3 Bi, 0.01-0.5 Sn, 0.05-0.3 Mn and the balance Fe with inevitable impurities. This silicon steel slab is subjected to rough-rolling at 1000-1200 deg.C and finish-rolling is execute to obtain the hot-rolled steel sheet. The cold-rolling is executed at 15-80% rolling reduction ratio without executing the hot-rolled sheet annealing, and after annealing at 700-1000 deg.C for a short time, the cold- rolling is executed at 40-90% rolling reduction ratio to obtain a specific sheet thickness. After heat-decarburizing at 800-1000 deg.C for 5-200sec, the heat nitriding treatment is executed under running the steel sheet. Successively, the anneal- separating agent is coated to apply the finish-annealing. |
