Molybdenum surface enrichment and release during transpassive dissolution of Ni-based alloys

The role of alloyed Mo during transpassive dissolution of four commercially available Ni-based alloys in neutral chloride solution was investigated by atomic emission spectroelectrochemistry. Time-resolved dissolution rates of Ni, Cr, Mo, and Fe were obtained as a function of applied potential. Mo enrichment occurred at the transpassive potentials and redissolved when the potential returned to the passive domain. These results suggest a...