ROLLING METHOD FOR COMPENSATING WIDTH VARIATION BY INSTANTANEOUS COILING TENSION OF HOT STRIP

摘要

PURPOSE: A rolling method for compensating width variation by instantaneous coiling tension of hot rolled strip is provided to prevent width shortage of hot rolled strip generated during coiling in the hot rolling process by performing widthwise rolling of bar in such a way that width of width shortage part is larger than width of the other part. CONSTITUTION: The rolling method for compensating width variation by instantaneous coiling tension of hot rolled strip comprises a step (401) of setting a width increment (A) for compensating the width shortage part by collecting past actual results of width shortage per thickness of coiling completed strip in the coiling process; a step (402) of setting the section as a rolling lengthwise position at which width is to be increased after calculating a time it takes for hot working average strain resistance to be air cooled to the lowermost temperature from a target temperature at the rear side of final rolling mill; a step (403) of setting length (L1) of width increased part of bar; a step (404) of calculating control initiating time (t1) and completion time (t2) of width increase during width rolling based on the value set in the setting step; a step (405) of increasing the width as much as the set width increment from the control initiating time (t1) to the completion time (t2) calculated in the calculation step during widthwise rolling; and a step (406) of performing normal widthwise rolling up to a tail part of bar by restoring the width increment to the original state.