| 摘要 |
<p>PURPOSE:To control the surface roughness of a cold rolled thin steel sheet with high accuracy by subjecting the steel plate to final rolling by making use of the coeffts. of influence of the rolling load and/or rear tension in a final rolling mill determined with respect to the surface roughness and the deviation value with respect to target surface roughness. CONSTITUTION:The coefft. of influence (1/Kp) of rolling load upon surface roughness in a final rolling mill 1 as well as the coefft. of influence of rear tension in the mill 11 upon the surface roughness are respectively determined beforehand and are stored in an operator 12. The target surface roughness X0 determined by the degree of surface finish and sheet thickness in the final product state of a cold rolled thin sheet is set in the operator 12; at the same time, the detected surface roughness X on the outlet side of the mill 11 which is measured 13, the actually measured rolling load P and the actually measured rear tension T are read therein. The operator 12 determines the deviation DELTAX between the roughness X and the roughness X0, and when the value DELTAX exceeds a blind zone (d), the operator operates the corrected rolling load P1 necessary for bringing the roughness X to the roughness X0 in accordance with the equation by using the above-described coeffts. (1/Kp). When the value P1 is in a prescribed permissible range, the operator transmits the load P1 as target rolling load P0 to a rolling reduction control device 14 which corrects the rolling load to the permissible threshold.</p> |
