Constitutive creep–fatigue crack growth methodology in two steels using a strip yield model

• Results from a strip yield creep–fatigue crack growth model for two steels are compared to experimental data.
• The two steels studied are 9Cr–1Mo and AISI 316L.
• C*-integral based creep model under-performed the constitutive model.
• Limitations of the strip yield model for this application are discussed.
• A constitutive creep material model is developed for AISI 316L stainless steel.

A creep–fatigue crack extension model based on a strip-yield methodology is presented and model predictions compared to experimental data over a range of temperatures, stresses and materials. In addition, a constitutive creep damage model for AISI 316L is developed. An empirical model based on the C* parameter and a constitutive model will be used to predict crack extension and compared. Advantages and limitations of the empirical creep model and the constitutive model are highlighted. In view of these limitations and the experimental comparisons, future development actions are recommended.