Prediction of the change of surface micro-defects in plate rolling

A new method of finite element analysis featuring an adaptive remeshing system was applied to calculate the change in surface micro-defects in plate rolling. In the;analysis, small meshes of sub-millimeter size were used around the defects. Rolling operations performed on plates having surface defects of several types; for instance, V-shaped and rectangular defects, were simulated and the defects remaining after rolling were investigated. Experiments were performed in order to verify the validity of the simulation results. Changes in defect shape in rolling were found to fall under two main categories: opening type and closing type. The influences of rolling conditions (roll diameter, lubrication, pass schedule, etc.) on existing defects after rolling were revealed. The proposed method for predicting surface defects is useful for producing defect-free products in rolling and forging processes.