Modeling and control of tribological properties for subsequent forming process in skin-pass rolling

Abstract

Abstract. The surface roughness including average roughness (Ra) and peak number (RPc) after skin-pass rolling influences the strip’s product properties, such as its friction coefficient in the subsequent sheet metal forming process. In order to both ensure an optimal tribological behavior and fulfill the process requirements of the following forming steps, predefined roughness combinations of Ra and RPc should be attained in skin-pass rolling. In this work, a preliminary friction model relating friction and combination of Ra and RPc is determined using flat die drawing tests for DC04 steel. The model is validated by deep drawing tests and embedded in a roughness control system for skin-pass rolling. To show a proof of concept for independent control of tribological properties from strip thickness, a simulation framework is implemented in Matlab/Simulink. The results indicate that the friction coefficient can be controlled between 0.0924 and 0.1003 for the considered test scenario (which is) characterized by a normal pressure of 75kN and a relative speed of 10mm/s.