涡轮盘用GH4706高温合金热变形行为

Hot deformation behavior of superalloy GH4706 for turbine disk

在变形温度为850~1100℃、应变速率为0.001~0.1 s^(-1)的条件下,利用Thermecmastor型热模拟试验机研究了锻态GH4706高温合金的热变形行为。综合考虑绝热温升和摩擦效应,对真应力-真应变曲线进行摩擦和温升修正,对比分析了摩擦-温度修正后的Arrhenius和Hansel-Spittel模型的相关系数r和平均相对误差AARE。结果表明:随着温度的降低和应变速率的提高,锻态GH4706高温合金的整体变形抗力逐渐变大,摩擦-温升效应所带来的误差也相对更大。建立的Arrhenius和Hansel-Spittel本构模型的相关系数分别为0.970和0.986,平均相对误差分别为13.17%和7.83%,Hansel-Spittel模型的预测精度更高。GH4706高温合金的动态再结晶对温度更为敏感,温度的升高有利于合金的动态再结晶,而应变速率的升高则会抑制合金的动态再结晶。

The hot deformation behavior of forged superalloy GH4706 was studied by a Thermomastor-type hot simulation testing machine under the deformation temperature of 850-1100 ℃ and the strain rate of 0.001-0.1 s^(-1).Taking into account the adiabatic temperature rise and friction effects,the friction and temperature rise corrections were applied to the true stress-true strain curve,and the correlation coefficients r and average relative error AARE of Arrhenius and Hansel-Spittel models after friction-temperature correction were compared and analyzed.The results indicate that with the decreasing of temperature and increasing of strain rate,the overall deformation resistance of forged superalloy GH4706 gradually increases,and the error caused by the friction-temperature rise effect is also relatively greater.The correlation coefficients of Arrhenius and Hansel-Spittel models are 0.970 and 0.986,the average relative errors are 13.17% and 7.83%,respectively,and the prediction accuracy of the Hansel-Spittel model is higher.The dynamic recrystallisation of superalloy GH4706 is more sensitive to the temperature,and increasing temperature is beneficial for the dynamic recrystallization of alloy,while increasing strain rate inhibits the dynamic recrystallization of alloy.