Microstructural features contributing to macroscopic corrosion: The role of oxide inclusions on the corrosion properties of additively manufactured 316L stainless steel

The electrochemical behavior of additively manufactured 316L stainless steel produced by argon and nitrogen atomized powder feedstock was studied in artificial sea water. A combination of computational thermodynamic calculations and experimental validation demonstrated that subtle differences in chemical composition of the powders led to the argon atomized material having more oxide inclusions compared to the nitrogen atomized material, which in turn resulted in higher susceptibility to localized corrosion. Additionally, improved electrochemical response of the additively manufactured materials relative to the wrought 316L was attributed to the passive films’ enrichment in chromium oxide.