高温轧制对AZ31B镁合金组织和性能的影响

Effects of High Temperature Rolling on Microstructure and Performance of AZ31B Magnesium Alloy

研究了高温轧制工艺对AZ31B镁合金微观组织、织构以及性能的影响规律。在轧制状态下,随着轧制温度从450℃升高至525℃,合金组织内部动态再结晶逐渐增多,孪晶数量不断减少,同时组织的均匀性也得到了改善,基面织构强度也呈下降的趋势。经350℃保温60min退火之后,合金板材内部发生了完全再结晶,孪晶组织消失,显微组织更均匀,板材基面织构强度也进一步减弱。由于基面织构强度的减弱,合金板材的室温成形性能随着轧制温度的升高得到显著提升,其杯突值由450℃时的5.6mm增大到525℃下的6.3mm,比450℃下的5.6mm提高了约12.5%。

The effect of high temperature rolling process on microstructure,texture and properties of AZ31B magnesium alloy is studied in this paper.Under the rolling condition,with the rolling temperature increasing from 450℃to 525℃,the dynamic recrystallization in the alloy microstructure increases gradually,the number of twin crystal decreases continuously,the homogeneity of the microstructure is improved,and the texture strength of the basal plane also decreases.After annealing at 350℃for 60min,complete recrystallization occurs in the alloy sheet,the twin structure disappears,the microstructure is more uniform,and the texture strength of the substrate is further weakened.Due to the decreases of the basal texture strength,the formability of the alloy sheet at room temperature is significantly improved with the increase of rolling temperature.The cup process value increases from 5.6mm at 450℃to 6.3mm at 525℃,which is 12.5%higher than that at 5.6mm at 450℃.