Variable Gauge Rolling Impact on the Edge Damage of AZ31 Magnesium Alloy Sheets

The edge damage behavior of AZ31 magnesium alloy plate was investigated by finite element software DEFORM, which is based on variable gauge rolling. The rolling temperature of magnesium plate was 350 degrees C, the rolling speed was 20 r/min and the lateral pre-deformation by vertical roll were 37.5%, 75% and 112.5% of plate thickness. Then the specimens that had been pre-deformed were rolled by flat roll with multi cycles of small reduction or single cycle with a large deformation. The results show that the variable gauge rolling process can significantly reduce edge damage of rolled magnesium plate. When vertical roll reduction is 37.5%, the variable gauge rolling process reach the best, and the maximum edge damage factor is 0.35. Variable gauge rolling process seems to be more suitable for large reduction rolling. The maximum damage factor is only 0.126 when vertical reduction is 75% and flat reduction is 49%. The value of vertical roll reduction is related to the initial thickness of magnesium plate.