Superaustenitic steel Sanicro 25 has been subjected to out‐of‐phase thermomechanical fatigue cycles with 10‐min dwell at peak temperature in the temperature range from 250°C to 700°C. The effect of the dwells on the cyclic response, internal structure and damage mechanism was studied. Cyclic hardening/softening curves, cyclic stress–strain curves and fatigue life curves were evaluated. The internal structure and nanoparticles representing the obstacles for dislocation motion were analysed and identified by energy dispersive X‐ray spectroscopy in scanning transmission electron microscope. Scanning electron microscopy combined with focused ion beam and electron backscatter diffraction was adopted to reveal the respective mechanisms responsible for fatigue crack nucleation and propagation. Effect of dwells in in‐phase and in out‐of‐phase cycling on the fatigue behaviour, on the modification of internal structure and damage mechanisms, were analysed and discussed.

中文翻译：

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停留时间对超级奥氏体钢Sanicro 25的热机械疲劳的影响

超级奥氏体钢Sanicro 25在250°C至700°C的峰值温度下经历了10分钟的停留时间异相热机械疲劳循环。研究了停留时间对循环响应，内部结构和破坏机理的影响。评估了循环硬化/软化曲线，循环应力-应变曲线和疲劳寿命曲线。通过扫描透射电子显微镜中的能量色散X射线光谱分析和鉴定了代表位错运动障碍的内部结构和纳米颗粒。采用扫描电子显微镜结合聚焦离子束和电子反向散射衍射，揭示了引起疲劳裂纹成核和扩展的各种机理。