铸态GH4169合金热变形行为及三种本构模型对比

在Gleeble-1500热力模拟机上对铸态GH4169合金进行热压缩试验,变形参数为:温度(1193～1373K)、应变速率(0.01～10s~(-1))、变形量50%。通过分析真应力真应变曲线,研究铸态GH4169合金的热变形行为;对比分析了Johnson-Cook(JC)、修正的Johnson-Cook(MJC)和应变补偿Arrhenius3种本构模型的相关系数(R)和平均相对误差(AARE)。结果表明:铸态GH4169合金的流变应力随变形温度的升高和应变速率的降低而减小。JC模型、MJC模型和应变补偿的Arrhenius本构模型的相关系数(R)分别为0.891、0.956和0.961,AARE依次为29.02%、11.16%和9.31%。因此,应变补偿的Arrhenius模型能够更为精确地描述铸态GH4169的热变形行为。

Hot deformation behavior of as-cast GH4169 alloy and comparison of three constitutive models

In this paper, the thermal compression test of as-cast GH4169 alloy is performed on a Gleeble-1500 thermo-mechanical simulator. The deformation parameters are: temperature (1193~1373 K), strain rate (0.01~10 s_^-1), and deformation 50%. By analyzing the true stress and true strain curve, the hot deformation behavior of as-cast GH4169 alloy was studied; the correlation coefficients (R) and average relative errors (AARE) of the three constitutive models of Johnson-Cook (JC), modified Johnson-Cook (MJC) and strain-compensated Arrhenius model are compared and analyzed. The results show that the flow stress of as-cast GH4169 alloy decreases with the increase of deformation temperature and the decrease of strain rate. The correlation coefficients (R) of the JC model, MJC model and strain-compensated Arrhenius constitutive model were 0.891, 0.956, and 0.961, and the average relative errors (AARE) were 29.02%, 11.16%, and 9.31%, respectively. Therefore, the strain-compensated Arrhenius model can describe the thermal deformation behavior of as-cast GH4169 more accurately.