Inconel 625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 1 000~1 200 ℃ and strain rates of 1~80 s-1 to obtain true stress-true strain curves.The critical conditions of dynamic recrystallization for Inconel 625 alloy were studied by using the work hardening rate θ,combined with the inflection point criterion of ln θ-ε curves and the minimum value of-■(ln θ)/■ε-ε curves.The results indicate that the ln θ-ε curve of Inconel 625 alloy presents the inflection point,and a minimum value of-■(ln θ)/■ε-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 εp,i.e.εc=0.69εp.The predicting model of critical strain is described as εc=4.41×10-4Z0.142 61.