The formation of edge cracks during rolling of metal sheet

Many metals tend to develop edge cracks during hot and cold rolling. Edge cracks need to be removed by a trimming operation, and they may cause rupture of the sheet in the rolling mill. Hence, there is a strong motivation to understand the mechanisms of edge crack formation and to develop predictive tools for controlling the phenomenon. The present work explores the applicability of damage mechanics models to this problem. In conjunction with a plausible failure criterion the Gologanu-Leblond model, which is based on non-spherical ductile void growth, is able to predict edge cracking and the characteristic zigzag damage pattern on the edge of the rolled sheet. The experimental determination of the model parameters remains a challenging task, since the stress and strain history at the edge of a rolled sheet is substantially different from the situation in a tensile test, and also from that in other conventional laboratory tests.