Prediction of creep crack growth behavior in ASME P92 steel welded joint

In the present study, the prediction of creep crack growth behavior in ASME P92 steel welded joint at 650 °C was carried out using elastic–plastic–creep finite element method (FEM) and theoretical prediction models, respectively. Then the predicted creep crack growth rate was correlated with parameter C* and compared with experimental data. It was observed that the creep crack growth behaviors calculated by the FEM and predicted by the modified NSW model under plain stress condition agreed well with experimental results. Hence, the appropriate creep residual life for the in-service components containing defects could be provided without conducting creep crack growth tests. Furthermore, creep crack growth behaviors of specimens with the initial crack located in the different zones of welded joint were also calculated. The simulation results revealed that the highest creep crack growth rate occurred at the interface between the fine grain heat affected zone and the base metal due to low creep strength and high constraint.