应变速率对617B镍基高温合金组织演变的影响

Effect of Strain Rate on the Microstructural Evolution of 617B Ni-base Superalloy

摘要:

采用Gleeble3800热模拟试验机，利用光学显微镜（Optical microscope, OM）、背散射电子衍射（Electron backscatter diffraction, EBSD）等手段，对不同应变速率条件下617 B镍基高温合金组织演变行为进行了研究，结果表明：对于617B合金，当应变速率≤1 s-1时，变形温升可忽略不计；当应变速率≥10 s-1时，温升明显；相同变形温度条件下，随着应变速率的增加，合金发生动态再结晶的峰值应变呈增加趋势；在应变速率0.1~20 s-1范围内，动态再结晶晶粒尺寸随着应变速率的提高呈现先减小再增大的变化趋势。

Abstract:

The microstructural evolution of 617B Ni-base superalloy at different strain rates were studied by Gleeble3800 thermal simulation testing machine, optical microscope and electron backscatter diffraction. The results show that for the 617B alloy, when the strain rate≤1 s-1, the deformation temperature rise is negligible. When the strain rate≥10 s-1, the temperature rise is significant. As the strain rate increases, the peak strain of dynamic recrystallization tends to increase when in the same deformation temperature condition. In the range of strain rate of 0.1~20 s-1, the dynamic recrystallized grain size trend at first decreases and then increases as the strain rate increases.