Carburization and oxidation of Fe-Cr-Ni alloys are common issues in petrochemical industry processes.
This study investigates the transition between carburization and oxidation behaviors of three different
kinds of commercial alloys: austenitic stainless steel UNS S34700, ferritic stainless steel UNS S44600,
and Ni based alloy UNS N06025. Equilibrium stable corrosion products, the alloy phases, and their
relative amounts for these three alloys were calculated at 1800°F (982°C) in CH4-H2O mixed gas
atmosphere. The effects of gas composition, temperature and alloy composition upon phase evolution
were investigated.