METHOD FOR ESTIMATING AND PREVENTING WIDTH DEVIATION OF STRIP IN STRIP ROLL PROCESS

摘要

PURPOSE: A method for predicting and preventing width deviation of plate having widthwise thickness difference when rolling plate is provided to control rolling of the plate to prevent width deviation before width deviation due to widthwise thickness difference is generated by predicting width deviation capable of being generated per each pass. CONSTITUTION: The method comprises first step (S110,S120) of contacting rolling rolls without rolling workpiece, measuring roll force and position of hydraulic cylinder after applying hydraulic pressure to cylinders in the lower part of the rolling rolls, and calculating stiffness coefficient of rolling mill using the measured roll force and position of hydraulic cylinder in case of replacing the rolling rolls; second step (S130,S140) of predicting and calculating width deviation by using the calculated stiffness coefficient, and predicted roll force of the top part and given thickness difference of the scarfing part calculated in pass schedule main program before performing rolling per each pass in case of widthwise rolling pass; third step (S150) of performing rolling by applying the predicted width deviation; and fourth step (S160,S170) of calculating actual results of left and right roll force deviations using the calculated stiffness difference between left and right parts of the rolling mill, actual results of left and right roll force deviation and actual results of left and right roll gap difference, calculating actual results of left and right width deviations, calculating actual results of roll gap correction value of the scarfing part and proceeding the second step after completing rolling per each pass if it is not the final pass by judging whether it is final pass or not, and terminating rolling operation in case that it is the final pass.