Corrosion of alumina-forming austenitic alloys under the supercritical carbon dioxide-based venus atmospheric surface conditions

Several grades of alumina-forming austenitic (AFA) stainless steel (SS) alloys were probed after exposure to simulated sCO2-based 467 degrees C Venus surface atmospheric conditions using the NASA Glenn Extreme Environ- ments Rig (GEER) for 30 days. AFA samples were characterized by gravimetric analysis, X-ray diffraction (XRD), and electron microscopy. All AFA samples formed multilayered scales in which the outer layer is mainly magnetite (Fe3O4) and nickel sulfides (Ni3S4, Ni4S3), and the inner layer is mainly chromia containing aluminum, (Cr,Al)2O3. The most resistant of the AFA alloys exhibited specific weight gain corrosion resistance similar to SS304, which formed an inner (Fe3_xCrxO4) spinel.

Automated summary

The performance of several alumina-forming austenitic stainless steel alloys exposed to simulated CO2-based Venus atmospheric conditions was investigated. The alloys formed multilayered oxide scales, with the outer layer mainly composed of magnetite and nickel sulfides, and the inner layer mainly containing aluminum chromia. The most corrosion-resistant alloy exhibited similar performance to SS304.