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在Gleeble-3800热模拟试验机上,采用热压缩实验研究了不同变形条件下Inconel 690合金的高温变形行为与组织演变特点。实验中采用的变形温度为1000～1200℃,变形量为70%,变形速率为1.0～80.0 s-1。根据实验结果获得了该合金的应力-应变关系,并对峰值应力进行了线性回归,由此得到了该合金的高温材料常数,激活能Q=417.6 kJ.mol-1,α=0.003196 MPa-1,n=7.51,并最终得到了Inconel 690合金的高温变形本构方程。通过金相显微镜研究了合金动态再结晶规律与温度和应变速率的关系,结果表明:变形温度对Inconel 690合金组织的影响很大,随温度的升高,动态再结晶百分数逐渐增加,且伴随着晶粒的长大;而提高应变速率,变形的时间缩短,位错密度迅速增大,动态再结晶的驱动力增加,也可以使再结晶后的晶粒细化;当温度为1150℃左右,应变速率50～80 s-1时,能够得到均匀细晶组织。
On the Gleeble-3800 thermal simulator, the hot deformation experiment and the high-temperature deformation behavior and microstructure evolution of Inconel 690 alloy under different deformation conditions were studied. The deformation temperature is 1000 ~ 1200 ℃, the deformation is 70% and the deformation rate is 1.0 ~ 80.0 s-1. According to the experimental results, the stress-strain relationship of the alloy was obtained and the peak stress was linearly regressed. The high-temperature material constants of the alloy were obtained. The activation energy Q = 417.6 kJ · mol-1 and α = 0.003196 MPa-1 , n = 7.51. Finally, the high temperature deformation constitutive equation of Inconel 690 alloy was obtained. The relationship between dynamic recrystallization and temperature and strain rate was studied by metallographic microscope. The results show that the deformation temperature has great influence on the microstructure of Inconel 690 alloy. With the increase of temperature, the percentage of dynamic recrystallization gradually increases, Grain growth; while increasing the strain rate, the deformation time is shortened, the dislocation density increases rapidly, the dynamic recrystallization driving force increases, can also make the recrystallized grain refinement; when the temperature is about 1150 ℃, Strain rate of 50 ~ 80 s-1, can be uniform fine grain structure.