Ni-Cr-W系高温合金晶界特征分布的研究

Grain Boundary Character Distribution in Ni-Cr-W Superalloy

摘要:

通过扫描电子显微镜(SEM)、电子背散射衍射（EBSD）、取向成像显微技术（OIM）研究了在不同冷轧及退火工艺下Ni-Cr-W系高温合金晶界特征分布的规律。结果表明，70%变形量下再结晶完成所需时间较短，特殊晶界比例随着退火时间延长先增加后减少；10%变形量下再结晶驱动力较小，再结晶所需时间较长，特殊晶界比例在长时间退火后达到最大值。在晶粒团簇内部，晶粒之间有Σ3n的取向关系，而不同的晶粒团簇间，晶粒则没有这种特殊的取向关系。

Abstract:

Grain boundary character distribution in cold-rolled Ni-Cr-W superalloys annealed for different time was investigated. Scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and orientation imaging microscopy (OIM) analyses were carried out. The results show that under the cold reduction of 70%, the samples’ recrystallization time is relatively short, and the ratio of special grain boundary increases firstly and then decreases with prolonging the annealing time; under the cold reduction of 10%, the recrystallization driving force is small, the recrystallization time is long, and the ratio of special grain boundary reaches the maximum after long-time annealing. In addition, boundaries have Σ3n misorientations inside the grains-cluster, while misorientations are random for those outside.