Effect of tensile dwell on low cycle fatigue of cast superalloy Inconel 792-5A at 800℃

摘要

Effect of tensile dwell on low cycle fatigue of cast Inconel 792-5A is studied in symmetrical strain cycling at 800℃. Cyclic hardening/softening curves, cyclic stress-strain curves (CSSC) and fatigue life curves were obtained in continuous cycling and in cycling with tensile dwells. Dwells have slight effect on hardening/softening curves at high strain amplitudes. CSSC in cycling with dwells is shifted to lower stress amplitudes. No significant effect of dwells on Basquin curves is observed. Density of slip markings in continuous cycling is significantly higher in comparison with cycling with dwells. Samples cycled with dwells are typical of high density of secondary cracks, although sporadic slip markings were also found.