Comparative assessment of strain-controlled fatigue performance of SS 316L at room and low temperatures. (January 2023)

• Record Type: Journal Article
• Authors: Maharaja, Hitarth; Das, Bimal; Singh, Amit; Mishra, Sushil
• Is Part Of: International journal of fatigue. Volume 166(2023)
• Publication Date: 2023-01
• Subjects: Low cycle fatigue -- Back stress -- Secondary hardening -- Strain-induced martensite -- EBSD; Materials -- Fatigue -- Periodicals; Materials -- Fatigue; Periodicals; 620.1122
• DOI: 10.1016/j.ijfatigue.2022.107251
• Languages: English
• ISSNs: 0142-1123

Abstract

Highlights: Secondary hardening observed for SS 316L specimens at −80 °C is a consequence of transformation of metastable austenite to martensite. Strain range effect on cyclic stress response is significant for specimens at −80 °C relative to RT specimen. Increase in cycles to failure for specimens at −80 °C than RT specimens is noticed. Development of compressive stress and back stress at the initiation of secondary hardening for specimens at −80 °C is noticed. Fatigue failure mechanism of SS 316 L at −80 °C is proposed. 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.