AbstractDespite the great success of the metal additive manufacturing process by Laser Fusion on Powder Bed (L-PBF), this technique still lacks maturity in several areas. Among its major challenges, the low fatigue strength of the L-PBF parts  caused, among other things, by two main types of defects. Firstly, a high surface roughness, mainly linked to the phenomenon of partial powder melting on the part surface . Secondly, internal defects are created during the building process and are randomly distributed in the material . The present study aims to investigate the effect of a second lasing  on the improvements of the characteristics of L-PBF parts. Based on preliminary experiments, two relasing strategies were selected. A high cycle fatigue campaign was subsequently carried out with a stress ratio of R=-1 on samples with or without relasing, in the as-built state or after polishing. Specimens printed in Net-Shape showed even after relasing and polishing, a much lower fatigue strength than those machined in the bulk after additive manufacturing . In addition, preliminary results show that the tested relasing conditions has a slight beneficial effect on the quasi-static and fatigue strength of the 316L obtained by L-PBF.
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