This review describes a recent advanced knowledge of the thermodynamics of Fe-Cr-O system in such low oxygen potential atmospheres as that in bright annealing. More attention is paid to the redox reactions of Fe-Cr-O system, especially the reaction of chromiun in a ferrous alloy with the water vapor in BA atmospheres having low dew points to form Cr2O3 and FeCr2O4. An outline of the surface characteristics of Fe-Cr alloy as bright annealed is given together with a discussion of the crystal structure of oxide films and their effect on the behavior of corrosion.
