| 摘要 |
PURPOSE:To produce a grain-oriented silicon steel sheet having superior mag netic properties uniform in a rolling direction and also having superior surface by specifying respective temp. regions and rolling reductions in the first pass and the second pass at the time of roughing in a hot rolling stage. CONSTITUTION:At the time of roughing in the hot rolling stage for a silicon- containing steel slab, rolling is performed in the first pass at >=1350 deg.C at 3-<20% rolling reduction, and also rolling is performed in the second pass under the condition where rolling temp. T is >=1350 deg.C and rolling reduction R satisfies the relationship in an inequality 60>=R(%)>=0.2T+300. Subsequently, the resulting plate is cold-rolled once or is cold-rolled twice while process- annealed between the cold rolling stages so as to be formed into the final sheet thickness. Then, the sheet is subjected to decarburizing annealing, and, after a separation agent at annealing is applied to the sheet, finish annealing is car ried out. By this method, the merits of a hot strip mill can be made the most of, and the grain-oriented silicon steel sheet excellent in magnetic properties and surface characteristics can be stably obtained. |
