轧制和退火对AZ31合金组织与性能的影响

Effect of Rolling and Annealing on Microstructure and Properties of AZ31 Alloy

以普通轧制和等径角轧制态AZ31合金为实验对象,研究了退火温度和退火时间对AZ31合金组织与成形性能的影响,并分析了其作用机理。结果表明,普通轧制态AZ31合金组织中可见大小不均的等轴晶粒,同时部分尺寸较大的晶粒内还有少量挛晶组织存在,而等径角轧制AZ31合金中晶粒尺寸与普通轧制态AZ31合金相当,但是挛晶数量明显增多;随着退火温度的升高和退火时间的延长,普通轧制和等径角轧制AZ31合金发生了初次再结晶和二次再结晶,晶粒趋于均匀、等轴化,并有逐渐粗化的趋势;退火温度为200℃和退火时间15 min以上的AZ31合金中的挛晶基本消失;退火处理后普通轧制和横向等径角轧制AZ31合金的断后伸长率和应变硬化指数增大,而纵向等径角轧制AZ31合金的应变硬化指数变化不大。

Taking AZ31 alloy with general rolling and equal channel angular rolling state as experimental object, the effect of annealing temperature and annealing time on microstructure and forming properties of AZ31 alloy was studied, and the mechanism of its action was analyzed. The results show that the microslructure of AZ31 alloy with general rolling state has uneven size of equiaxed grains, while a few twin structure exist in the large grain. The grain size of AZ31 alloy with equal channel angular rolling state is similar to AZ31 alloy with general rolling state. With the increase of annealing temperature and annealing time, initial recrystallization and second recrystallization occur in AZ31 alloy with general rolling and equal channel angular rolling, the grains tend to be uniform, and there is a tendency of coarsening; the elongation and strain hardening index of AZ31 alloy with general rolling and transverse equal channel angular rolling increase after annealing, while the longitudinal strain hardening index has little change.