Fatigue Behavior of Stainless Steel 304L Including Strain Hardening, Prestraining, and Mean Stress Effects

Abstract

This paper discusses cyclic deformation and fatigue behaviors of stainless steel 304L and aluminum 7075-T6. Effects of loading sequence, mean strain or stress, and prestraining were investigated. The behavior of aluminum is shown not to be affected by preloading, whereas the behavior of stainless steel is greatly influenced by prior loading. Mean stress relaxation in strain control and ratcheting in load control and their influence on fatigue life are discussed. Some unusual mean strain test results are presented for SS304L, where in spite of mean stress relaxation fatigue lives were significantly longer than fully-reversed tests. Prestraining indicated no effect on either deformation or fatigue behavior of aluminum, while it induced considerable hardening in SS304L and led to different results on fatigue life, depending on the test control mode. Possible mechanisms for secondary hardening observed in some tests, characterized by a continuous increase in the stress response and leading to runout fatigue life, are also discussed. The Smith–Watson–Topper parameter was shown to correlate most of the experimental data for both materials under different loading conditions.

Effect of Cryogenic Temperature on Low-Cycle Fatigue Behavior of AISI 304L Welded Joint

“…However, this is an experimental observation and more test data is required to explain the thickness effect. In general, there are three different characteristics (short hardening, slight softening, and significant secondary hardening) under the cyclic behavior of AISI 304L base metal [3,20]. It is noted that the softening behavior of AISI 304L depends on the applied strain amplitude.…”

“…This implies that changes in the strain ratio do not significantly affect the fatigue performance of a welded joint in low-cycle region. Many studies also demonstrated that an increased mean stress has more influence on the fatigue characteristics than the effect of the strain ratio in low-cycle regions [3,21]. cyclic softening compared to the tendency of R = −1.…”

“…Among austenitic stainless steels, AISI 304L is commonly employed to manufacture liquefied natural gas (LNG) cargo tanks because of its higher performance in a cryogenic environment. In addition, this material exhibits a special characteristic called secondary hardening owing to stress-or strain-induced phase transformation [3,4]. This state, called the martensitic transformation, leads to hardening behavior during low-cycle fatigue.…”

Toward consistent fatigue crack initiation criteria for 304L austenitic stainless steel under multi-axial loads

“…Table 1 lists the description of the experimental fatigue data employed in this study. The data were gathered from EDF, its partners and the literature [11][12][13][14][15][16][17][18][19], which was obtained from standard specimens made of the 304L stainless steel as discussed in details in the corresponding references. It should be emphasized that all these tests are under constant amplitude fatigue loadings.…”

Effect of axial and shear prehardening on fatigue behaviour of the 304L SS

“…To determine the required parameters for the reliable and accurate prediction of fatigue life, the effect of this prior straining on the subsequent cyclic behavior and fatigue, with or without mean stress and strain, must be considered. Several previous works were interested in the prehardening effects on the fatigue life of metallic materials [1,2]; where, mean stress can be positive or negative during fatigue tests. Therefore, our objective here is to study the isolate effect of a prehardening in axial and shear direction on the fatigue at zero mean stress and/or strain.…”