Abstract:

In the hot rolling of magnesium alloy , the grain refinement may result in the strength and ductility improvement, and the variation of rolling parameters helps to control the microstructure of the alloy. This paper focuses on the effects of the reduction per pass on the microstructure and properties of AZ31 magnesium alloy. The results show that , with the increase of the reduction per pass , the strain rate improves and a dynamic re-CIγstallization occurs , which results in the grain refinement and hardness improvement. However , surface cracks may occur when the reduction per pass increases to a critical value. Moreover , it is found that hot rolling with large strain may decrease the number of rolling passes. Thus , fine-grained AZ31 Mg sheets with a grain size of about 2 to 5μm can be successfully prepared by hot-rolling with large reduction per pass.

Key words: magnesium alloy, rolling, recrystallization, microstructure