Energy-based approach to predict the fatigue life behavior of pre-strained Fe-18Mn TWIP steel

Abstract

The influence of pre-strain on the fatigue life behavior of Fe-18Mn twinning-induced plasticity (TWIP) steel was investigated by performing strain-controlled low-cycle fatigue (LCF) and stress-controlled high-cycle fatigue (HCF) tests with variation of the amount of pre-strain. The pre-strain to the as-received plate was achieved through a cold rolling process; thickness reductions of 10 and 30% were applied. The results revealed that both the LCF and HCF resistances were strongly dependent on the amount of pre-strain but showed vastly different effects; with increasing pre-strain, LCF resistance was degraded but HCF resistance was improved. An energy-based concept was adopted and modified to capture the pre-strain effect on the fatigue life behavior by considering the energy consumed by pre-straining. The developed model was further extended to establish a correlation between the LCF and HCF life data. The results showed that the HCF life behavior could be successfully predicted from the LCF life data. (C) 2011 Elsevier B.V. All rights reserved.