Simulation of transfer layer formation in strip drawing of stainless steel

The development of a transfer layer during forming of stainless steel is simulated using a strip drawing rig. A Zygo three-dimensional profilometer, a scanning electronic microscope (SEM) and an X-ray photo-electronic spectrometer (XPS) have been used to examine the morphology and composition of the transfer layer. The effects of lubrication regime and die material have been investigated. Results from the strip drawing tests show a significant effect of the lubrication regime on the development of the transfer layer, while the properties of the different die materials are less important. The role of the transfer layer on the surface finish of the workpiece has been examined. Results show that a transfer layer may help reduce the area fraction of surface pits present, for the shot–blast strip, and hence improve its surface finish. With initially smooth cold rolled strips, scratches on the strip surface are observed due to the transfer layer, making the deformed strips rougher.