JPS645605A - Method for stress-relief rolling in continuous annealing device - Google Patents

Abstract

PURPOSE:To prevent generation of bad appearance and shape defects in spite of response delay and variance in required time for position changing of intermediate rolls by controlling a position of intemediate rolls of a 6-high skin pass rolling mill by detecting a sheet width changing point in accordance with a size of rear side sheet width. CONSTITUTION:A welding point position computing element 22 previously sets timing to change a position of intermediate rolls 14A, 14B and to change rolling conditions such as setting of a rolling pressure. At the time of detecting a welding point of a steel sheet 10A by a detector 20, if a rear side sheet width is narrow, a shift of the rolls 14A, 14B is started at a point within a given distance from a point right under a rolling mill in the downstream side, if a rear side sheet width is large, a shift of the rolls 14A, 14B is completed by that point. And that, a position of the rolls 14A, 14B presetted by a preset computing element 30, a roll bending amount, and a drafting position are set to a prescribed value with the timing decided in the above description to prevent variations in shapes of the sheet 10A.