METHOD FOR DECREASING EDGE DROP IN ROLLING PLATE

摘要

PURPOSE:To decrease the edge drop in rolling plate by heating the ends of a plate prior to the final finishing pass in rolling plate and providing a dogbone of a good shape to the transverse end of the plate at the adequate rolling reduction corresponding to the plate thickness in edging rolling then executing finish rolling. CONSTITUTION:The body crown in the central part in the thickness of the horizontally rolled plate 3 can be corrected by eliminating the deflection of roll shafts by a multiple rolling mill, etc., but the edge drop arising from the flatness of work rolls is difficult to be corrected. The edge drop width of the plate material 3 and the edge quantity thereof are first detected by a plate thickness measuring instrument 11 and the temp. difference of the end parts is detected by a transverse plate temp. measuring instrument 17. A calculator 12 controls the peak position of the dogbone and controls the increment of the dogbone associated to the plate thickness by heating up the end edges with an edge heater 16 according to the result of the above-mentioned detection and executing edging with a vertical rolling mill 13. The plate is thereafter rolled to a flat plate by a horizontal rolling mill 14 and the result thereof is detected by a crown meter 15. The edge drop is decreased by the above-mentioned method.