Initial stages of oxide growth on AM stainless steel exposed to a supercritical CO2 environment

Wrought and additively manufactured (AM) 316 L stainless steel samples were exposed to a simulated Brayton cycle supercritical CO2 (sCO2) environment, at temperature of 450 °C pressure 76 bar in 99.999% for 2 weeks. The ground surfaces wrought AM specimens had average oxide thickness 95 51 µm, respectively, composed primarily Fe Cr oxides. An as-printed sample was also the sCO2 environment exhibited negligible oxidation during 2-week exposure because thick rich Mn silicate native covering most surface.