Fatigue behaviors of Z2CND18.12N stainless steel under thermal-mechanical cycling

Liubing WANG 1) , Dunji YU 1) , Fei XUE 2) , Weiwei YU 2) , Jian CHEN 3) and Xu CHEN 1) 1) School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China 2) Suzhou Nuclear Power Institute, Suzhou 240051, China 3) Key Laboratory of Efficient & Clean Energy Utilization, College of Hunan Province, Changsha University of Science and Technology, Changsha 410114, China

摘 要：Tests under mechanical strain control were performed to investigate the TMF behavior of Z2CND18.12N within the temperature range between 150–550 ? C. Different strain amplitudes and phase-angles were applied. Total strain controlled low cycle fatigue test was also performed at the peak temperature of TMF cycling. The results show that the cyclic stress response of the material displayed an initial hardening regime followed by a saturation period and then cyclic softening till failure. The TMF cycling leads to the development of significant amounts of mean stress. Some life prediction models were employed to predict the TMF life of Z2CND18.12N, and the results indicate that the energy-based models provide good prediction on the thermal-mechanical fatigue behaviors of this material. An optical microscopic observation shows that the surface crack initiations and crack propagations are typically transgranular mode.

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