Inconel 617合金热变形过程中几何必须位错的演变

Evolution of Geometrically Necessary Dislocations in Inconel 617 Alloy during Hot Deformation

利用热模拟试验机对Inconel 617合金在温度1000~1200℃,应变速率0.001~1 s^(-1)范围内进行热压缩试验。采用电子背散射衍射和透射电子显微镜技术研究了其热压缩过程中的微观组织演变和几何必须位错(GND)特征。结果表明,随着温度的升高和应变速率的降低,再结晶程度增大,GND密度降低,并且明显的绝热升温效应加速了再结晶的形核和长大。Inconel 617合金热变形过程中大量的位错墙相互缠结,GND首先在大角度晶界处塞积,然后形成亚晶界,最终演变为再结晶晶粒。

The hot compression test of Inconel 617 alloy was carried out at 1000℃-1200℃and the strain rate of 0.001 s^(-1)-1 s^(-1) by the thermal simulation testing machine.Electron backscatter diffraction and transmission electron microscopy techniques were used to investigate the microstructure evolution and the characteristics of geometrically necessary dislocations(GND)during hot compression.The results show that with the increase of temperature and the decrease of strain rate,the degree of recrystallization increases,the density of GND decreases,and the obvious adiabatic heating effect accelerates the nucleation and growth of recrystallization.During the thermal deformation of Inconel 617 alloy,a large number of dislocation walls are entangled with each other.GND first accumulates at the large angle grain boundary,then forms sub-grain boundary,and finally evolves into recrystallized grain.