HOT ROLLING METHOD FOR PREVENTING PERIPHERAL FLAW OF STEEL SHEET

PURPOSE: To reduce the depth of seam flaw without increasing the overlap of products and loss of yield at the time of hot-rolling a steel sheet and to make this method applicable to also a specified material of finishing temp. such as a control rolled stock. CONSTITUTION: In the midway of hot rolling stage of the steel sheet, the shapes of end faces along the rolling direction of a material S to be rolled are measured with devices 1 for measuring the shape of end face, the position of overlap (a) in double bulge or the position of an inflection point (b) in single bulge is recognized in an arithmetic processor 2, the heating control of a heating furnace 3 is executed based on these results and the position (a) or (b) is made to coincide with the center of thickness in the rolling stage. In the case of double bulge, when the position of the overlap (a) is on a surface side than the center position of thickness, the amount of heating on the surface side of slab in the slab heating furnace 3 is relatively increased in accordance with the deviation of the position of the overlap (a) from the central position of thickness.