Fatigue Performance of Additively Manufactured 316L Stainless Steel in Air

Abstract

With its ability of rapid prototyping and cost-effective production, additive manufacturing (AM) or 3D printing technology has the potential to improve the operating performance of the current nuclear reactors and accelerate the development of advanced nuclear power systems. In this study, two AM 316L stainless steel (SS) tubes, serving as surrogates for complex components that are more likely to benefit from AM technology, were fabricated using the Renishaw AM400 Laser Powder Bed Fusion (L-PBF) system. The microstructure and porosity of the AM material were analyzed, and the low-cycle fatigue performance was evaluated at the temperature typical of light water reactors (LWRs). It was found that the porosity level of the as-printed material was low, ranging from 0.06% to 0.3%. The low-cycle fatigue behavior of the AM material in air was comparable to that of wrought stainless steels, suggesting that the microstructure and porosity level resulting from a well-controlled printing process do not significantly impact the air fatigue performance of AM materials. This study indicates that the use of AM alloys in their as-printed condition is promising, however, further research on environmental fatigue, crack initiation, and stress corrosion cracking (SCC) is required to provide the performance information necessary to qualify AM materials for broader applications in LWRs.