| 摘要 |
PURPOSE:To improve productivity and to reduce scale flaws and ridging in continuous hot rolling of a ferritic stainless steel slab by eliminating the time waiting until the start of finish rolling after the end of rough rolling and increasing the start temp. thereof. CONSTITUTION:The starting temp. for rough rolling of a slab is set at <=1,200 deg.C and the starting temp. for continuous finish rolling at >=900 deg.C, and recrystallization rolling of >=25% rolling pass draft is executed in plural passes. Further, thr rolling temp. in the post stage of the finish rolling is set at <=800 deg.C, and after the slab is rolled at >=25% cumulative draft, the hot rolled plate is subjected to annealing for a short time within 10min at 700-1,100 deg.C, after which it is cold-rolled and is finish-annealed. Here, if the starting temp. for the finish rolling is set at >=900 deg.C, the rolling is accomplished in the recrystallization temp. region and the continuous rolling is accomplished; therefore, the recrystallization effect equivalent metallurgically to that of single pass large screw-down rolling is obtained by setting single pass draft at >=25% and executing cumulative rolling. |
