Sulfidation Kinetics of Iron and Ferritic Iron‐Cobalt Alloys

Pure Fe and ferritic Fe‐Co alloys react with atmospheres in the range at temperatures of 533°–700°C to form a solid single‐phase scale of . Parabolic scaling kinetics are observed in all cases, the magnitude of the rate constant, its activation energy, and its dependence being independent of alloy composition. The sulfidation of iron is shown to be controlled by lattice diffusion of iron through the sulfide and the quantitative applicability of Wagner's parabolic scaling theory is verified.