Fatigue properties of SLM 316L stainless steel parts: Experimental and numerical analysis

This paper presents a comparative study on the fatigue crack propagation behavior of 316L stainless steel specimens fabricated by selective laser melting (SLM) and traditional rolling processes, based on both the digital image correlation (DIC) and finite element methods. The speckle images during cyclic loading were recorded using the DIC system, and the crack growth rates, strain field distributions, crack opening displacements (COD), and damage evolution processes of both types of specimens were analyzed. The fracture surfaces were observed and discussed by scanning electron microscopy. The results indicate that the fatigue performance of SLM specimens is comparable to that of traditionally rolled specimens, with the primary differences manifesting in the later stages of crack propagation. Using the extended finite element method (XFEM) in Abaqus, models containing pore defects were simulated. The study reveals that at lower porosity levels, the fatigue performance of SLM specimens approaches that of traditionally rolled specimens, and the influence of pore size on fatigue life is more significant. The influence of porosity on fatigue performance depends on the combination of several factors.