Group items tagged

"Formation of a surface layer, whether it is based on an oxide, carbonate, sulfate, or any other compound, is a major factor in corrosion resistance, particularly if the layer effectively isolates the metal substratum from the environment. Such a naturally formed coating must be diffusion- and moisture-resistant to be effective. Ordinary iron does not naturally form an effective barrier; its rust permits oxygen and moisture to penetrate and continue rusting. Thus, unless precautions are taken, such as applying a protective coating over the surface, failure will eventually occur."