Abstract
This study was carried out for the purpose of investigating the corrosionbehavior and mechanism on a separator for a molten carbonate fuel cell underboth the electrolyte and cathode side environment. A SUS310S austenitic stainlesssteel was used as the separator material. Corrosion proceeded via threesteps; a formation step of corrosion product in which rapid corrosion take placesuntil a stable corrosion product is formed after the beginning of corrosion;secondly, a protection step against corrosion until breakaway occurs after theformation step of the stable corrosion product;finally, an advance step of corrosionafter breakaway. From the standpoint of the behavior of the elementsin the separator, Fe, Cr and Ni were formed richly in the region of the corrosionproduct, in the region of corrosion protection, and at the Cr-depleted zone respectively. With respect to the corrosion mechanism, direct reaction with electrolyteand elements of the separator at the cathode side was the main corrosionmechanism, and the final corrosion product was LiFeO2. The corrosion rate ofthe separator at the cathode side was rapid at the initial stage of corrosion.However, the corrosion rate was decreased due to the resistant effect of chromiumoxide.
