Edge Cracks and Temperature Field of AZ31B Magnesium Alloy Sheet

AZ31B cast rolled magnesium alloy sheets were rolled under conditions with temperature of 350 degrees C and rolling speed of 0.5 m/s, whose dimension was 150 mmx150 mmx7 mm, and rolling reduction 10%, 20%, and 30%. Then numerical simulation was carried out under these same rolling conditions. Moreover, magnesium alloy sheet's surface temperature field and stress state were analyzed, and then its mathematics model of surface temperature gradient was established. Edge cracks' damage and temperature distribution of finite element numerical simulation's results were analyzed in addition to their microstructure after rolled. Simulated results were compared with experimented. It can be drawn the conclutions that at the same temperature, with rolling reduction increasing, plastic deformation heat of magnesium sheet will increase, but small reduction will promote brittle phase of MgZn2 and Mg2Si generated. Therefore, reducing quantities of long strip twins and brittle phase is one of key factors about controlling edge cracks.