Effects of manufacturing parameters and mechanical post-processing on stainless steel 316L processed by laser powder bed fusion

Stainless steel 316L is a frequently used metal in additive manufacturing owing to its favorable strength-ductility synergy and corrosion resistance, and laser powder bed fusion (L-PBF) is the most commonly applied additive manufacturing method for processing 316L. Manufacturing components from stainless steel 316L via L-PBF benefits the geometrical accuracy of the process and properties of the material simultaneously. Although alloy 316L has been used in additive manufacturing for a long time, its strengthening mechanisms and microstructure have yet to be fully understood. Thus, this study aimed to perform a comprehensive investigation of the microstructural features and mechanical properties of this alloy. A thorough review of other studies on stainless steel 316L processed via L-PBF is provided, along with experimental results, to elucidate the mechanisms controlling and influencing the properties of this material. Microstructural analysis, hardness measurements, and tensile, fatigue, and Charpy tests were performed. The results showed that stainless steel 316L processed by L-PBF could satisfactorily replace its conventionally manufactured counterparts for service under static, cyclic, and impact loads. However, under cyclic loading, the fatigue performance of the additively manufactured material may require enhancement by machining or mechanical post-processing.