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

Abstract

In this paper, a new framework to correlate the experimental data of the 304L stainless steel under multi-axial fatigue loadings using a reference curve identified from the experimental data of standard uni-axial fatigue tests is proposed. A total of 15 available fatigue crack initiation criteria are tested on the experimental data of 225 fatigue tests collected from EDF (formerly known as Electricity of France), its partners and the literature. Based on the computational results, it appears that most of the crack initiation parameters of the 15 available criteria can be used to correlate the experimental fatigue data for the 304L stainless steel under uni-axial loadings. Under bi-axial loadings, most of these parameters appear not to be quite consistent. Two criteria are modified in order to better correlate the experimental fatigue data under bi-axial loads. A simple statistical approach to evaluate the consistency of the crack initiation criteria is also proposed. Based on the limited available experimental fagtigue data and within the new framework in this paper, the computational results show that the equivalent crack initiation parameters of the Varvani-Farahani’s criterion, the modified Lagoda–Macha–Sakane’s criterion and the modified Varvani-Farahani’s criterion can be used to correlate the experimental fatigue data under both uni-axial and bi-axial loadings for the 304L stainless steel. These criteria may be used to predict the fatigue life of the material under different loading and testing conditions by using the experimental data from the standard uni-axial fatigue tests.