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研究了定向凝固镍基高温合金DZ17G在800℃下的低周疲劳性能，得到其循环应力-应变曲线和应变-寿命曲线，并用最小二乘法回归得到Manson-Coffin方程的数学表达式；对疲劳断口进行了宏观及微观分析，发现裂纹主要在试样内部及近表面缺陷处萌生，裂纹一旦形成即穿晶扩展，且扩展方向垂直于加载轴．
The low cycle fatigue behavior of the directional solidified Ni-based superalloy DZ17G at 800 ℃ was investigated. The cyclic stress-strain curves and strain-life curves were obtained. The mathematical expressions of the Manson-Coffin equation were obtained by regression with the least square method. The macroscopic and microscopic analyzes were carried out. It is found that the cracks mainly initiate inside and near the surface of the specimen. Once the crack is formed, the crack propagates and the direction of expansion is perpendicular to the loading axis.