Anodic polarization studies have been conducted in an aqueous solution of , at 92°C, and compared with studies in . Anodic films were examined by electron diffraction and x‐ray energy analysis and all results compared with published data on and equilibria. In particular, it was concluded that the delay of passivity in the sulfide solution, relative to , was due to the incorporation of S2− ions into the lattice to render it nonprotective. Passivity did not occur until the lattice S2− content was decreased at more noble potentials, this process being influenced by anodic oxidation of aqueous S2− ions. The polarization behavior is relevant to corrosion and stress corrosion cracking in the pulp and paper industry.