Cyclic deformation behavior and life prediction of P92 steel welded joints under thermomechanical fatigue loadings

In the present work, thermomechanical fatigue behavior and life prediction of P92 steel welded joints under various mechanical strain amplitudes and phase angles are investigated. Results demonstrate that the welded joints exhibit significant cyclic softening during fatigue process and the thermomechanical fatigue life is strain amplitude and phase angle dependent. The decrease in strain amplitude and the increase in phase angle induce the increase in fatigue life. Fracture analysis indicates that the fracture position changes significantly with the strain amplitude and phase angle. Finally, a modified energy-based life prediction model is proposed by considering the effects of phase angle and mean stress.

Automated summary

The present work investigates the thermomechanical fatigue behavior and life prediction of P92 steel welded joints under various mechanical strain amplitudes and phase angles. The results show that welded joints exhibit significant cyclic softening during fatigue process, with fatigue life being dependent on both strain amplitude and phase angle. A decrease in strain amplitude and an increase in phase angle lead to an increase in fatigue life, while fracture position changes significantly with changes in strain amplitude and phase angle. Finally, a modified energy-based life prediction model is proposed by considering the effects of phase angle and mean stress.