Comparative assessment of strain-controlled fatigue performance of SS 316L at room and low temperatures

Abstract

In the present study, strain-controlled low cycle fatigue (LCF) behaviour of SS 316L at room temperature (RT) and −80 ℃ were investigated. RT LCF specimens show cyclic softening, whereas −80 ℃ specimens show initial cyclic softening followed by hardening due to strain-induced martensitic transformation (SIMT). Fatigue damage evolution mechanism is proposed for specimens tested at −80 °C, where compressive stresses develop due to SIMT and retards the crack growth. This leads to an increase in fatigue life for −80 °C specimens. An increase in back stress component at the initiation of secondary hardening is noticed for −80 °C specimens.