| 摘要 |
PURPOSE:To manufacture the ultralow core loss grain-oriented silicon steel sheet without glass coating films by allowing steel having a specified chemical compsn. to undergo specified stages. CONSTITUTION:A slab contg., as steel components, by weight, 0.021 to 0.075% C, 2.5 to 4.5% Si, 0.01 to 0.04% acid soluble Al, 0.0030 to 0.0130% N, <0.014% S and 0.050<0.45% Mn is heated to <=1280 deg.C, is thereafter subjected to hot rolling, is subjected to cold rolling for one time or >= two times including intermediate annealing to regulate its sheet thickness into a final one, which is thereafter subjected to decarburizing annealing, is subjected to nitriding treatment, is coated with a separation agent for annealing, is thereafter subjected to high temp. finish annealing, is subjected to domain fractionating treatment before or after hit flattening and is subjected to coating and baking of an insulating coating film agent. In this way, the high magnetic flux density ultralow core loss grain-oriented silicon steel sheet without glass coating films can be manufactured. |
