ABSTRACT
This type of coating is formed by the interaction of a metal surface with other elements in a solution. The coating layers are composed of inorganic compounds that are chemically inert. The formations of inert compounds on the surface reduce both anodic and cathodic areas and delay the transit of reactive species to the base metal. Thus, the situation on a coated surface results in increases in the slopes of anodic and cathodic polarization curves, thereby decreasing the corrosion rate of the substrate.
