METHOD FOR CONTROLLING THICKNESS IN CONTINUOUS HOT ROLLING MILL

PURPOSE:To provide a thickness controlling method that good thickness can be attained from the tip of a hot strip. CONSTITUTION:In a continuous hot rolling mill, at least a thickness gage 11 and a thermometer 12 are provided between stands. When the tip of a material 13 to be rolled is bitten into the stand just before the thickness gage 11, rolling force and draft position of the stand are detected. The thickness of the material 13 to be rolled on the outlet side of the stand is calculated using a gagemeter equation from these detected values and draft positions of the next and succeeding stands is corrected based on the deviation between this thickness on the outlet side and the target thickness. Further, when the tip of the material 13 to be rolled is passed through the thickness gage 11 and the thermometer 12, the thickness and temp. of the material 13 to be rolled are respectively detected and the draft positions of the next and succeeding stands that are already corrected are again corrected based on the deviation between this detected value and the thickness that is previously determined by calculation.