Creep-fatigue life prediction and interaction diagram in nickel-based GH4169 superalloy at 650 °C based on cycle-by-cycle concept

The purposes of the present work are to extend the previous energy-based model on the basis of strain energy density exhaustion and to estimate creep-fatigue endurance and accumulated damage using cycle-by-cycle concept in tension-hold-only tests. The nickel-based GH4169 superalloy at 650 °C is employed to fit material constants and to verify the prediction capacity of the present model under various loading conditions. The present model exhibits a higher accuracy than some existing models, especially for certain loading waveforms, where the half-life cycle cannot be considered as a representative one. In addition, the trajectory for time-dependent accumulated damage during the operating period can be monitored in the creep-fatigue interaction diagram.