High temperature oxidation of steels in CO2 containing impurities

Abstract Future power systems require steels that resist corrosion in high temperature CO2 containing combustion products/impurities. Here we evaluate the corrosion behavior of several commercial steels exposed to 95% CO2-4 % H2O-1 % O2, with/without 0.1 % SO2, at 550 °C and 1 atm. High-Cr steels formed thin Cr-rich oxides and low-Cr steels thick Fe-rich oxides during SO2-free exposures. Additions of SO2 had little effect on low-Cr steels but enhanced corrosion of high-Cr steels, where S within the chromia scale led to its failure and subsequent Fe-rich oxide nodule growth. The results are rationalized by considering the thermodynamic and kinetic factors controlling the reaction.