Small fatigue crack initiation and propagation behavior of Inconel 617 was studied by in-situ SEM observation, electron back-scattered diffraction (EBSD), digital image correlation (DIC), crystal plasticity finite element method (CPFEM) and extended finite element method (XFEM) in this paper. The experimental results indicated that different surface corrosion methods used to display surface microstructure will affect the small fatigue cracking mode of Inconel 617. The local micro-scale strain field of Inconel 617 near the notch and crack tip was quantitatively measured by a new grain scale DIC method. The CPFEM-XFEM simulation model of small fatigue crack initiation and propagation characteristics of Inconel 617 was established. A new framework for small fatigue crack path and lifetime prediction at the polycrystalline scale was constructed, which includes the influences of slip system and grain boundary on small fatigue crack initiation and growth rate.

原位研究Inconel 617的小疲劳裂纹萌生和扩展行为本文采用SEM观察、电子背散射衍射(EBSD)、数字图像相关(DIC)、晶体塑性有限元法(CPFEM)和扩展有限元法(XFEM)。实验结果表明，用于显示表面微观结构的不同表面腐蚀方法会影响Inconel 617的小疲劳开裂模式。采用新的晶粒尺度DIC定量测量Inconel 617缺口和裂纹尖端附近的局部微观尺度应变场方法。建立了Inconel 617小疲劳裂纹萌生与扩展特性的CPFEM-XFEM模拟模型。构建了多晶尺度小疲劳裂纹路径和寿命预测的新框架，