Incoloy825合金热变形为与组织演变

Microstructure evolution and hot deformation behavior of Incoloy825 alloy

摘要:

通过热压缩实验，研究了Incoloy825合金在变形量为60％,温度为950~1150℃和应变速率0.001~1s-1范围内热变形行为。基于Arrhenius方程和Zener-Hollomon参数模型，建立该合金的本构方程模型。采用金相显微镜（OM）和电子背散射衍射（EBSD）技术研究了合金的组织演变规律。结果表明，随着变形温度的升高或应变速率的降低，DRX的百分含量增加。热变形过程中DRX既包括晶界弓起形核机制的不连续动态再结晶（DDRX）也包括渐进式亚晶旋转形核机制的连续动态再结晶（CDRX）。随着变形温度的升高或应变速率的降低DDRX增强而CDRX减弱。此外随着温度的升高或应变速率的降低，低角度晶界逐渐向高角度晶界转化。同时随机分布的Σ3孪晶界趋于均匀化，且对动态再结晶起促进作用。

Abstract:

The hot deformation behavior of Incoloy 825 alloy under 60% deformation,950 ~ 1150 ℃ temperature and 0.001 ~ 1s-1 strain rate was studied by hot compression test. Based on Arrhenius equation and Zener Hollomen parameter model, the constitutive equation model of the alloy was established. The microstructure evolution of the alloy was studied by means of metallographic microscope (OM) and electron backscattering diffraction (EBSD). The results show that the percentage of DRX increases with the increase of deformation temperature or the decrease of strain rate. DRX includes both discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) during hot deformation. With the increase of deformation temperature or the decrease of strain rate DDRX increases and CDRX decreases. In addition, with the increase of temperature or the decrease of strain rate, the low angle grain boundary gradually transforms to the high angle grain boundary. Simultaneous random distribution Σ3 twin boundaries tend to homogenize, It also promotes the dynamic recrystallization.