METHOD FOR CONTROLLING ROLLING OF INCLINED ROLL PIERCING MACHINE

PURPOSE:To improve the dimensional accuracy by measuring the outer diameter and the extended length of blank pipes to be pierced at the outlet side, by successively measuring the most suitable set value of the outer diameter and the wall thickness of blank pipes by modifying correction terms of models of mathematical expression of the outer diameter and the wall thickness of blank pipes to which the correction terms are added, through calculations, and by feeding back the most suitable set value to the rolling of the next material to be rolled. CONSTITUTION:The outer diameter and the extended length of every blank pipe after rolling are measured, and the measured value and the set-up value of the piercing mill are automatically inputted into a computer, and then, correction terms of models of mathematical expression of the outer diameter and the wall thickness of blank pipes to which the correction terms are added are modified through calculations. Then, the most suitable values of rolling conditions are successively calculated by taking the rolling possible conditions and flaw-free conditions into consideration, and this value is fed back to the rolling of the next material.