THE CORROSION BEHAVIOR OF POLYCRYSTALLINE AND SINGLE-CRYSTAL CHROMIUM - A REVISED MODEL

A revised model for the corrosion behavior of pure chromium has been developed. This model applies to both polycrystals and single crystals. The model has been developed using results from polarization and impedance measurements. In the revised model, the observed diffusion controlled process has been ascribed to surface diffusion of an intermediate in the dissolution reaction mechanism, instead of diffusion controlled dissolution at the grain boundaries. From the model, the impedance could be calculated for the active, the active-passive, and the first part of the passive region.