Influence of Dwell Time and Dwell Position on Creep–Fatigue Interaction and Deformation Mechanisms in Haynes 282 Superalloy

The influence of dwell time and dwell position on the creep–fatigue interaction (CFI) behavior of heat‐treated Haynes 282 superalloy was investigated to delineate the individual contribution to the deformation mechanisms under both symmetric and asymmetric waveforms. The CFI test specimens were subjected to 5‐minute tensile, compressive, and dual‐dwell waveforms, followed by zero‐dwell tests (low‐cycle fatigue) under fully reversed loading at 760°C and a constant strain amplitude of ±0.6%. LCF specimens (zero‐dwell) exhibited prolonged fatigue life in contrast to the CFI specimens. Tensile dwell proved the most detrimental, while recovery‐assisted stress redistribution and oxidation‐induced crack closure improved fatigue life under the dual dwell condition. Irrespective of the waveform, cyclic hardening was primarily driven by weakly coupled dislocation–precipitate interactions, while gamma prime (γ′) shearing, recovery, and dislocation annihilation governed cyclic softening. Dwell loading modifies texture by reducing cube/ θ ‐fibers and enhancing γ‐fiber and Goss components via creep‐assisted stress redistribution. The same creep effect also drives a shift from transgranular cracking in zero‐dwell tests to intergranular or mixed‐mode failure under dwell conditions, indicating grain‐boundary weakening and reduced fatigue life.