Cyclic deformation response of austenitic Ni-based alloy: Mechanical behavior, internal stress evolution and microstructural feature

Cyclic deformation response of an austenitic Ni-based alloy was investigated by symmetrical/asymmetrical strain cycling tests at room temperature (RT) and 350 degrees C. The effects of strain amplitude/ratio and ambient temperature on the cyclic deformation behavior were discussed in terms of microstructural features and internal stresses. Results indicate that the cyclic hardening/softening at RT is mainly attributed to the increase/decrease in back stress. Whilst at 350 degrees C, the contribution of effective stress to cyclic deformation response becomes important due to the planar slip promoted by the occurrence of dynamic strain aging (DSA) throughout the fatigue process. Accordingly, the continuous cyclic hardening at 350 degrees C comes from the combined action of back stress and effective stress.

Automated summary

The cyclic deformation response of an austenitic Ni-based alloy was investigated through strain cycling tests at different temperatures. The effects of strain amplitude/ratio and ambient temperature on cyclic deformation behavior were discussed. The results showed that at room temperature, cyclic hardening/softening was mainly attributed to changes in back stress, while at 350 degrees C, the contribution of effective stress became important due to the occurrence of dynamic strain aging.