Abstract: With the development of aerospace, energy and chemical industry, the high temperature equipment is used more and more widely. Such equipment is subjected to creep damage during steady-state operation and thermal fatigue or thermo-mechanical fatigue damage in the frequent on-off operation or the sudden change of operating mode, its potential danger is great , once an accident happens, it is always catastrophic. The mechanical mechanism of the creep and thermal fatigue interaction is studied by considering the bilinear kinematic hardening property and creep characteristics of the material. When the interaction occurs: ① The more the compressive inelastic strain generated in the temperature rising and holding process is, the greater the tensile stress and strain generated in the cooling process will be. Therefore, brittle material with high compressive yield limit and low creep rate should be preferred in designing the components subjected to creep-thermal fatigue damage. ② Creep affects the stress amplitude and the mean stress of the cycle, and makes them stable after a certain number of cycles. Thus, the creep-thermal fatigue damage can be equaled to thermo-mechanical fatigue damage, which simplifies the life prediction and failure test.

Key words: Creep-thermal fatigue, Interaction, Life prediction, Thermomechanical fatigue