Modeling the effect of water vapor on the interfacial behavior of high-temperature air in contact with Fe20Cr surfaces

This work uses molecular dynamics simulation to provide an atomistic view of the contrasting interfacial behavior between high-temperature dry air and wet (10–40 vol.% water) air in contact with stainless steels. A key finding was that H2O preferentially adsorbs and displaces oxygen at the metal–fluid interface. We also discuss how these findings are consistent with Ehlers et al. proposed competitive adsorption mechanism for the interpretation of the breakaway oxidation, and highlight their impact on other properties.

► Atomistic view of the contrasting interfacial behavior between high-temperature dry- and wet-air in contact with stainless steels.
► H2O preferentially adsorbs and displaces oxygen at the metal-fluid interface.
► Findings are consistent with Ehlers et al.’s proposed competitive adsorption mechanism for the interpretation of the breakaway oxidation.
► Significant impact of the inhomogeneous density distribution between the interfacial- and bulk-environments on the fluid transport.