Research on the Cause and Control Method of Edge Warping Defect during Hot Finishing Rolling

Abstract

Different from the cross-section profile defects caused by uneven roll wear or external forces during hot finishing rolling, the edge warping defect often occurs and has special local characteristics. However, the cause and control method of edge warping are still unclear. By superposition calculating the roll shape, it is found that the high-order comprehensive roll gap contour formed by the superposition of the bathtub-shaped roll thermal contour and parabolic original roll shape is the main cause of strip edge warping. To ensure that the comprehensive roll gap contour is parabolic rather than the original roll shape, the target curve of the comprehensive roll contour in the form of a parabola is determined according to the amplitude of the middle position of the comprehensive roll contour of the last strip in a standard rolling unit, and then subtract the thermal contour curve of the last strip to obtain the desired curve of the antithermal original roll shape. In theory and application, the optimization of the original roll shape can effectively avoid the occurrence of edge warping defect.