Research of edge defect formation in plate rolling by finite element method

For hot-rolled flat products major losses of steel are due to surface defects, which are caused by the quality of an incoming continuous cast slab. Each typical surface defect of a continuous cast slab if not detected and eliminated transforms into a surface defect of a rolled plate. One of the most critical problems of hot rolled plates is connected with the longitudinal surface cracks located at the distance up to 80 mm from the edges. This study covers the research and simulation of transformation of surface cracks into the edge defects of the hot-rolled plate by finite element method. It is shown that the mechanism of crack movement during plate rolling comes from inclination of front and tail faces of slab due to temperature gradient between top and bottom surfaces. To reduce the possibility of corner crack formation it is proposed to increase the temperature of the edge zone of the slab due to the rounding of edges or by induction heating. The results of the study will be useful for material saving during plate rolling.