Predicting Critical Friction in a Two-Roll Cross Wedge Rolling Process

Excessive interfacial slip is one of the primary failure mechanisms in the cross wedge rolling (CWR) process. In order to predict operating conditions that lead to excess interfacial slip, an analytical method is presented for determining the critical rolling condition in a two-roll CWR operation. Based on a transverse section of the tool-workpiece contact interface, the method uses Bowden and Oxley’s friction models to obtain the critical rolling condition in CWR as a direct function of tool geometry and workpiece area reduction. The relative accuracy of the results obtained from each friction model is then ascertained and discussed by comparing the analytical results to experiments.