Effects of Rolling on Microstructures and Hardness of AZ31 Magnesium Alloy Rolled Sheets with Different Length-width Ratios

AZ31 magnesium sheets with different sizes were rolled at 300℃ and per pass reduction is 0.4mm. Microstructure test and hardness test were used to investigate the microstructures and properties evolution rule of middle and edge area. And the effects of sheets sizes on microstructures and properties of sheets were also studied. The results show that, under the same experimental conditions, as the rolling passes and accumulated deformation increase, the hardness of middle and edge appear alternated rising on the whole. With the length-width ratio decreasing, the hardness at the edge of the rolled sheet becomes lower in the per pass reduction under the same conditions, and more recrystallized grains are generated at the middle of the rolled sheets. When the edge cracks occuring, the hardness of edges are showing a downward trend, as the length-width ratio decreases.