Creep-fatigue properties and life prediction of TP321 austenitic stainless steel at high temperature

TP321 austenitic stainless steel exhibits excellent strength, toughness, and high-temperature corrosion resistance, making it a preferred material for critical components in high-temperature environments, particularly within the nuclear industry. When a nuclear power plant is operated in a high-temperature environment, its critical components are subjected to creep-fatigue interaction. In order to study the creep-fatigue performance of TP321 austenitic stainless steel at high temperatures, creep-fatigue tests are conducted and combine with microstructure inspection to analyze the effects of temperature, holding time and strain amplitude on the deformation and damage behavior of TP321 austenitic stainless steel. Then, three different life prediction models are used to predict the life of the creep-fatigue tests. The results show that increasing the test temperature, holding time and strain amplitude decreases the creep-fatigue life of the material. A tendency for cracks and cavities to promote each other’s expansion is observed, which is an important reason for the decrease in creep-fatigue life. Of the three life prediction models, the modified strain energy density (MSEDE) exhaustion model gives the most accurate lifespan prediction.