Hot compression tests of a FGH96 superalloy under the conditions of temperatures from 1020 to 1110 °C and strain rates from 10⁻³ to 1 s⁻¹ were carried out on a Gleeble-3180D thermo simulator. The microstructure evolution and nucleation mechanisms of dynamic recrystallization (DRX) for the superalloy were analyzed by electron backscatter diffraction (EBSD) technique and transmission electron microscope (TEM). A DEFORM-3D Finite Element (FE) software was used to simulate the distributions of deformation and microstructures of the compressed specimens. The results show that the flow stress curves of FGH96 superalloy exhibit typical features of dynamic recrystallization (DRX). The constitutive equation is established based on the friction-corrected flow stress data. Increasing temperature or decreasing strain rate is found to result in the increases of both the DRX fraction and the grain size. The nucleation mechanisms of DRX for the superalloy mainly include dominant discontinuous dynamic recrystallization (DDRX) and assisting nucleation by twins. The prediction models of DRX, which are expressed as a function of Z parameter, are obtained on the basis of the compression data and quantitatively microstructural characterization. By comparing the simulated results with that of the experiment, the accuracy of the developed DRX models is validated.

FGH96高温合金在1020至1110°C的温度和10 ^-3至1 s ^-1的应变率的条件下的热压缩测试在Gleeble-3180D热模拟仪上进行。通过电子背散射衍射（EBSD）技术和透射电子显微镜（TEM）分析了超合金动态再结晶（DRX）的组织演变和成核机理。使用DEFORM-3D有限元（FE）软件来模拟压缩试样的变形和微观结构的分布。结果表明，FGH96合金的流变应力曲线表现出动态重结晶（DRX）的典型特征。基于摩擦校正后的流动应力数据建立本构方程。发现温度升高或应变速率降低导致DRX分数和晶粒尺寸均增加。DRX高温合金的成核机理主要包括显性不连续动态重结晶（DDRX）和双晶辅助成核。DRX的预测模型表示为Z参数是根据压缩数据和定量的微观结构表征获得的。通过将模拟结果与实验结果进行比较，验证了开发的DRX模型的准确性。