Cyclic strain rate effect on martensitic transformation and fatigue behaviour of an austenitic stainless steel |
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| Authors: | J. W. Pegues S. Shao N. Shamsaei J. A. Schneider R. D. Moser |
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| Affiliation: | 1. Laboratory for Fatigue & Additive Manufacturing Excellence (FAME), Department of Mechanical Engineering, Auburn University, Auburn, AL, USA;2. Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA, USA;3. Department of Mechanical and Aerospace Engineering, University of Alabama, Huntsville, AL, USA;4. U.S. Army Engineer Research and Development Center, Vicksburg, MS, USA |
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| Abstract: | In this study, the effect of strain rate on the cyclic behaviour of 304L stainless steel is investigated to unveil the complex interrelationship between martensitic phase transformation, secondary hardening, cyclic deformation and fatigue behaviour of this alloy. A series of uniaxial strain controlled fatigue tests with varying cyclic strain rates were conducted at zero and non‐zero mean strain conditions. Secondary hardening was found to be closely related to the volume fraction of strain‐induced martensite which was affected by adiabatic heating due to increasing cyclic strain rates. Tests with lower secondary hardening rates maintained lower stress amplitudes during cyclic loading which resulted in longer fatigue lives for similar strain amplitudes. Fatigue resistance of 304L stainless steel was found to be more sensitive to changes in strain rate than the presence of mean strain. The mean strain effect was minimal due to the significant mean stress relaxation in this material. |
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| Keywords: | 304L stainless steel cyclic deformation fatigue mean strain mean stress secondary hardening |
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