Simulation of Edge Defects Behavior of Slabs in the Sizing Press and Roughing Mill of a Hot Strip Mill

Defects in cast slabs can be developed or reduced during hot rolling depending on size, location and distribution of primary defects, quality of the alloy, as well as rolling parameters. Defects, such as cracks, voids, or inclusions and their behavior in the material during rolling severely affects the final product quality. The aim of this work is to develop a 3D finite element method (FEM) model in order to analyze the behavior of surface defects during the deformation in the sizing press and in the roughing mill during hot rolling. To reach this aim, firstly different FEM models for different ideal (without defects and misalignment) slab geometries, rolled with different reduction steps, are developed and studied. After verifying these ideal models, the defects are implemented in the models and their behaviors during deformation are studied. It could be stated that there is a borderline condition for the surface topography and position in the side of the slab, moving the defect to the top or bottom surface area. Moreover, it could be stated that defects implemented on the surface of the slab remain on the surface and do not move into the slab during sizing in the press and the roughing procedure. In this work, the behavior of defects in steel slabs in sizing press and roughing mill is studied. Different slabs with different geometries are chosen and initially are simulated ideally (without having any defects). After verifying the models, the defects are inserted to the different cases and slabs are simulated having defects.