Optimizing the corrosion resistance of selective laser melted 316L austenitic stainless steel by adjusting solid solution treatment parameters

This study examines the influence of solid solution heat treatment on the microstructure, passive films, and corrosion behavior of selective laser melted (SLMed) 316L stainless steel. The results demonstrate that a solid solution treatment at 1100 °C for 0.25 h effectively optimizes the corrosion resistance of SLMed 316L stainless steel. The corrosion resistance of SLMed 316L SS samples increases with increasing the solid solution temperature and/or duration, which is mainly associated with the solution of Cr- and Mo-enriched precipitate phases as well as the increase in the ratio of the (111) plane to the (200) plane after increasing the solid solution temperature and/or duration can effectively improve the corrosion resistance of passive films. In contrast, the SLM-produced 316L stainless steel sample treated at 1100 °C shows a rapid decline in corrosion resistance with prolonged solid solution duration, primarily due to the formation of detrimental MnS inclusions. These findings have significant implications for establishing an optimal heat treatment strategy regarding improving the corrosion resistance of SLMed 316L stainless steel. • Corrosion resistance of SLMed 316L SS is enhanced at 1100 °C for 0.25 h. • The ratio of (111) to (200) plane increases to 2.25 at 1100 °C for 0.25 h. • Extensive MnS inclusions leads to dramatic deterioration in corrosion resistance at 1100 °C for 0.25 h.