| 摘要 |
PURPOSE:To decrease the edge cracks of a hot rolled sheet in the stage of subjecting a high Si content grain oriented electrical steel slab to hot rolling by specifying the coolest point temp. of the slab in the heating zone of a continuous heating furnace and the surface temp. of the slab in the soaking zone. CONSTITUTION:The grain oriented electrical steel slab contg. >=3.0% Si is heated in the continuous heating furnace and is then cross-rolled by edger rolls in a hot rolling stage to prevent the generation of the edge cracks of the hot rolled sheet. The slab in the heating zone of the continuous heating furnace is heated to the temp. range of 1,280-1,380 deg.C with the coolest point (central part in the thickness direction) of the slab. The surface temp. of the slab is 1,330-1,410 deg.C. The slab surface temp. in the subsequent soaking zone is so maintained as to attain the temp. range between the temp. lower by 10 deg.C than the surface temp. of the slab in the heating zone and 1,420 deg.C. The edge cracks to be generated in the stage of cross-rolling the high Si content grain oriented electrical steel slab with the edger rolls are considerably decreased and the yield is improved. |
