Cold tandem rolling method and cold tandem rolling mill

摘要

PROBLEM TO BE SOLVED: To simultaneously prevent a heat scratch and a plate breaking and to manufacture a steel plate having an excellent plate width precision by controlling a shape controller so that a plate width variable quantity does not exceed the pre-determined allowable value of the late width variable quantity, applying the rolling tension of the specified % or above of the deforming resistance of a rolling stock in at least the final stand and then rolling. SOLUTION: The rolling stock is rolled under the tension of e.g. 30-40% or above of the deforming resistance of the rolling stock, and the plate width of the rolling stock is detected with plate width measuring devices 6a, 6e in the inlet and outlet sides of a tandem rolling mill. The cumulative value of the plate width variation in a first to fourth stands is calculated with an operation processor 8 from the detected plate width in the inlet and outlet sides of the tandem rolling mill. When this value exceeds the allowable value wherein the plate breaking is possibly generated in the tandem rolling mill, the plate width correcting quantity to be corrected is calculated, the stand wherein the plate breaking is possibly generated is specified, and the plate width is preferentially controlled with shape controllers 4a-4d.