PURPOSE: To improve controllability of a sheet shape without necessitating to slow down rolling speed at the time of correcting defect of sheet shape by providing sleeve type divided back-up rolls on the rolling mill in the final stage of a rolling mill line of plural stages.
CONSTITUTION: A tandem mill line 20 is composed by arranging 1st-5th stage rolling mills 21-25 which are provided with upper and lower work rolls 51 and back-up rolls 61 in a line. A rolled stock 50 is stepwise rolled through these rolling mills 21-25 successively. Then, the sleeve type divided back-up rolls 10 are provided in the rolling mill 25 at least in the final stage of the rolling mill line 20 of the plural stages. The rolled stock 50 is rolled while executing sheet shape control like a curve of the second order with the rolling mills 21-24, rolled to an aimed thickness and also combined sheet shape control is executed to the rolled stock 50 using M-shaped crown pattern in the screw-down position V. In this way, the unsuitable sheet shape of the rolled stock is properly controlled.
HORIE KAZUHIKO
MATSUDA YUTAKA
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