GH625合金的热变形行为

Hot Deformation Behaviors of Superalloy GH625

采用Gleeble-1500热模拟试验机研究了GH625高温合金在应变速率为0.001～1 s-1、变形温度为1223～1373 K条件下的热变形行为。结果表明:当变形温度一定时,随应变速率的升高,合金的峰值应力σp和稳态流动应力σs及对应的应变εp和εs均升高;当变形速率一定时,随变形温度的升高,σp和σs以及εs均降低,但εp基本保持不变。GH625合金在热压缩变形过程中应变速率的降低和变形温度的升高均有利于动态再结晶的发生;根据应力-应变曲线,通过线性回归获得GH625合金的本构方程。

The hot compressive deformation behaviors of superalloy GH625 were studied in the temperature range from 1223 K to 1373K and the strain rates from 0.001 s-1 to 1 s-1 on Gleeble-1500 hot simulator. Experimental results show that the peak stress σp, starting steady-state stress ors, and corresponding strain 8p, zs increases with the increase of strain rate ε at constant temperature. At constant strain rate, σp, σs and εs, drop with the increase of temperature, but εp does not change obviously. The dynamic recrystallization of superalloy GH625 occurs easily with the decrease of strain rate and the increase of deformation temperature during hot compressive deformation; based on the analysis of strain-stress curves, the hot deformation constitutive equation of superalloy GH625 is obtained through linear regression.