Heat Treatment Effect on Corrosion Resistance and Microstructure of Selective Laser Melted 316L Stainless Steel

Recently, 316L stainless steel fabricated by selective laser melting (SLM) has been widely used in various fields; however, the influence of post-processing heat treatments on its corrosion resistance has not yet been fully clarified in the literature. In this study, the corrosion behavior of SLM-built 316L stainless steel is investigated in its as-built state and after various heat-treatments, and the results are compared with those of conventionally processed (wrought) 316L. Electrochemical measurements show that the SLM-manufactured specimens exhibit lower corrosion resistance than their wrought counterparts. Furthermore, neither stress-relief annealing at 650 °C nor solution (recrystallization) treatment at 1050 °C leads to a measurable improvement in the corrosion resistance of the SLM-manufactured material under the conditions investigated.