Inconel625合金高速热变形动态再结晶的临界条件

通过等温热压缩试验获得Inconel625合金在变形温度为1000～1200℃，应变速率为1～80S^-1条件下的真应力-应变曲线，利用加工硬化率，结合lnθ-ε曲线上的拐点判据及-δ（1nθ）／δε-ε曲线上的最小值，来研究Inconel625合金动态再结晶的临界条件。结果表明，在该实验条件下，Inconel625合金的lnθε曲线均出现拐点特征，对应的-δ（lnθ）／δε-ε曲线出现最小值，该最小值处对应的应变即为临界应变；临界应变随应变速率的增大和变形温度的降低而增加，并且临界应变和峰值应变之间有一定的关系，即εc=0．69εp；动态再结晶时临界应变的预测模型可以表示为εc=4．41×10^-4Z^0.14261。

Critical Conditions Hot of Dynamic Recrystallization during High Speed Deformation of Inconel 625 Alloy

Hot compression tests of Inconel 625 alloy were conducted at deformation temperature range of 1 000- 200 ℃ and strain rates of 1-80 s^-1 to obtain true stress-true strain curves. The critical conditions of dynamic recrystallization for In- conel 625 alloy were studied by using the work hardening rate θ, combined with the inflection point criterion of in θ-ε curves and the minimum value of -δ（ln θ）/δε-ε curves. The results indicate that the in θ-ε curve of Inconel 625 alloy presents the inflection point, and a minimum value of -δ（In θ）/δε-ε curve appears, which means the critical strain εc. The critical strain increases with the strain rate increasing and the temperature decreasing. And there is a relationship between the critical strain εc and peak strain ε, i. e. εc = 0.69%. The predicting model of critical strain is described as εc = 4.41 × 10^-4 Z^0.142.61