Influence of the Strain Rate on the Low Cycle Fatigue Life of an Austenitic Stainless Steel with a Ground Surface Finish in Different Environments

Abstract:

This paper focuses on the influence of strain rate in Low Cycle Fatigue (LCF) of a 304L austenitic stainless steel at 300 °C in different environments (secondary vacuum, air and Pressurized Water Reactor (PWR) water environment). Moreover test samples are ground to obtain a surface finish rougher than all that could be found in nuclear power plants. Different strain rates (4x10^-3, 1x10^-4 and 1x10^-5 s^-1) are studied, with a triangular waveform at a total strain amplitude of ±0.6%. The influence of strain rate on cyclic stress-strain behavior and fatigue life is firstly analyzed in secondary vacuum, considered as a non-active environment. Then, interactions between stain rate and environmental effects in Air and in PWR environment are presented. In all environments, a decrease in strain rate leads to a negative strain rate dependence of the stress response and a reduction in fatigue life. Finally, SEM observations of fatigue striations in PWR environment indicate a crack propagation rate enhancement when the strain rate is decreased.

• Periodical: Advanced Materials Research (Volumes 891-892)
• Pages: 1320-1326
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.891-892.1320
• Online since: March 2014
• Authors: Thibault Poulain*, José Mendez, Gilbert Hénaff, Laurent de Baglion
• Keywords: Austenitic Stainless Steel, Ground Surface Finish, Low Cycle Fatigue, PWR Water Environment, Strain Rate

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