An interaction crack growth model for creep-brittle superalloys with high temperature dwell time

• We proposed an intensity factor to characterize the interaction crack growth.
• The capacity of interaction model was verified by experiments on FGH97 superalloy.
• Applicability of the model was confirmed by data from literature.
• Limitation of the model and parameter fitting procedure were discussed.

A three-term interaction crack growth model developed for creep-brittle materials is restudied. Derivation of cycle–time interaction intensity factor from the Gaussian equation is discussed. The model’s prediction ability was verified by test data of a nickel base superalloy under 750°C with 25s dwell time. Data of two other superalloys namely Alloy 718 and Hastelloy® X from literature are analyzed to further examine applicability of the model. Satisfactory results are obtained. Parameter fitting procedure and limitation of the model are discussed at the end.