The effect of atomic hydrogen on the kinetics of iron passivation in neutral solutions

Abstract

Current-time dependences are recorded on iron in borate buffer (pH 7.4 and 6.7) and its mixture with NS4 solution (pH 6.7) at the potentials of passivity, active-passive transition, and prepassivation of iron. Hydrogenation of the metal is found to accelerate the dissolution of iron in steady passive state, produce no effect on the growth of a barrier layer, and prevent the formation of a primary passivating film. Atomic hydrogen decelerates the active dissolution of iron, which determines the anodic current at the initial stage of the metal passivation.