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.