028合金热变形行为及加工图

Hot deformation behavior and processing map of 028 alloy

采用Gleeble-1500热模拟压缩试验机对028合金进行恒温热压缩实验,变形温度为1120~1220℃,应变速率为0.1~10 s-1,研究了028合金的热变形行为及加工图,得到了028合金最佳的热挤压工艺。结果表明,建立的本构方程能较好的预测028合金在热变形中的峰值应力;028合金在热加工过程中发生动态再结晶,随变形温度升高,动态再结晶百分数和晶粒尺寸逐渐增加,动态再结晶晶粒尺寸随应变速率增加而减小,加工图中存在两个安全区、一个失稳区和一个危险区,028合金的最佳热挤压温度为1200℃,应变速率为1 s-1。

The isothermal compression of 028 alloy experiment was carried out by Gleeble-1500 thermal simulation compression test machine,the deformation temperature of 1120-1220 ℃ and the strain rate of 0.1-10 s- 1,the hot deformation behavior and processing map of the 028alloy were studied,and the optimal thermal extrusion process of the 028 alloy was obtained.The results show that the constitutive equation established can predict the peak stress of the 028 alloy in hot deformation better.Dynamic recrystallization occurrs in 028 alloy during hot deformation,with the increasing of deformation temperature,the percentage and grain size of dynamic recrystallization increase,the grain size of dynamic recrystallization decreases with the increasing of strain rate,there are two security zones,an unstable region and a danger zone in the processing map,the optimal thermal extrusion temperature is 1200 ℃,and strain rate is 1 s- 1.