Fatigue-creep behaviors of Ni-Fe based superalloy under various testing conditions

The fatigue-creep properties of Ni-Fe based superalloy with varying strain amplitude, temperature and holding duration are studied in ambient air. The results demonstrated that the number of cycles decreases greatly with increasing strain amplitude from 0.5% to 1.0%, and the < 001 > RD texture in the microstructure is conformed along the deformation direction. Both high temperature and holding duration are key factors in the reduction of fatigue cycles. It is determined that the dislocations bypass the second phase particles during deformation process, and the critical shear stress transition is observed. Different from the temperature factor, higher holding time leads to the growth of the second phase, and which finally exceeds the critical size of dislocation cutting, leading to the inducement for dislocations bypassing the second phase. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The fatigue-creep properties of Ni-Fe based superalloy under different conditions vary significantly, showing that increasing strain amplitude, temperature, and holding time all have an impact on fatigue cycles. Dislocations bypass second phase particles during deformation, and longer holding time leads to the growth of the second phase, ultimately exceeding the critical size for dislocation cutting.