Fatigue behavior of additive manufactured 316L stainless steel under axial versus rotating-bending loading: Synergistic effects of stress gradient, surface roughness, and volumetric defects

In this study, the stress gradient effects on the fatigue behavior of 316L stainless steel (SS) specimens fabricated using two different laser beam-powder bed fusion (LB-PBF) processes were investigated, with an emphasis on the surface roughness and volumetric defects. The fatigue behavior of LB-PBF 316L SS largely depended on the applied stress amplitude. Under higher stress amplitudes, rotating-bending specimens generally exhibited better fatigue resistance as compared to the axial specimens subjected to the same nominal stresses. At lower stress amplitudes, the surface roughness and/or volumetric defects became more significant life-limiting factors for LBPBF 316L SS.