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研究了铸造Ｎｉ基高温合金Ｋ４１７在６５０—９００℃温度范围内总应变控制条件下的低周疲劳性能和断裂行为．对应变－寿命数据和循环应力－应变数据进行了分析，进而给出了Ｋ４１７合金在不同实验温度下的应变疲劳参数．合金在循环形变过程中可表现为循环硬化、循环软化或循环稳定，而具体呈现何种循环应力响应行为则主要取决于实验温度和外加总应变幅．疲劳试样断日表面的扫描电子显微分析结果表明，疲劳裂纹通常萌生于铸造缺陷处，而且在所有实验条件下疲劳裂纹的萌生和扩展均以穿晶方式发生
The low cycle fatigue behavior and fracture behavior of cast Ni-base superalloy K417 under total strain control at 650-900 ℃ were investigated. The strain-life data and cyclic stress-strain data are analyzed, and then the strain fatigue parameters of K417 alloy at different experimental temperatures are given. The alloy can show cyclic hardening, cyclic softening or cyclic stability in the process of cyclic deformation. The specific cyclic stress response behavior depends mainly on the experimental temperature and the applied total strain amplitude. The results of scanning electron microscopy on the broken surface of the fatigue specimen showed that the fatigue cracks usually originated in the casting defects and the initiation and propagation of fatigue cracks occurred by transgranular method under all the experimental conditions