Study on ultra-low cycle fatigue behavior of austenitic stainless steel

摘要

In order to study the ultra-low cycle fatigue (UCLF) behavior of austenitic stainless steel, uniaxial tensile tests and cyclic loading tests of round bar specimens and notched specimens for S30408 austenitic stainless steel were carried out respectively. In terms of the experimental results of smooth round bars, monotonic and cyclic constitutive models of austenitic stainless steel 530408 were calibrated. Furthermore, the parameters of stress modified critical strain (SMCS) model, void growth model (VGM) and cyclic void growth model (CVGM) were calibrated through comparing the notched round bar tests with the corresponding finite element analyses (FEA). Finally, the influence of element size on the fracture prediction of the micromechanical models was analyzed. Results indicated that the cyclic hardening responses of austenitic stainless steel were obvious. Meanwhile, the calibrated numerical simulation was able to well capture the key characteristics observed in the tests. In addition, as for VGM and SMCS models, the fracture prediction values increased with the element size. Last but not least, in terms of the degraded parameter and the fracture toughness parameters, it was proved that ULCF fracture resistance of austenitic stainless steel was better than common structural steels. Therefore, from this perspective, austenitic stainless steel structures have potential advantages to be applied in seismic areas.