CONTROL METHOD OF SHEET WIDTH IN HOT ROLLING

PURPOSE:To spread a sheet width on the way of rolling and to obtain a desired sheet width by bending work rolls in the planes parallel to the rolling direction of work rolls. CONSTITUTION:Each of upper and lower work rolls 1 is bent so as to be convex in the rolling direction by actuating either of hydraulic cylinders 7. Then the surfaces along the radial directions at respective parts of the work roll 1 are deformed into the state where the surfaces are laterally opened toward the front in the rolling direction, and a material 8 to be rolled is spread in width in addition to the width to be spreaded by rolling reduction. Further, a control device 9 controls the actuating conditions of cylinders 7 in accordance with the signals inputted from sheet thickness detectors 10a, 10b.