Metallic coatings may be used for corrosion control in two different ways. A metallic coating with greater corrosion resistance than the substrate metal acts as a barrier to the environment. The metallic coating serves as a durable, corrosion resistant outer layer, while the substrate provides strength and load bearing capabilities. A metallic coating that is more galvanically active than the substrate provides cathodic protection to the substrate. It will corrode galvanically and provide cathodic protection to the substrate at breaks or imperfections in the coating.

Several methods may be used to apply metal coatings, including electroplating, electroless plating, spraying, hot dipping, chemical vapor deposition, and ion vapor deposition. The corrosion resistance of a substrate can also be improved by metallurgically bonding a surface layer of a metal or an alloy with good corrosion resistance to the core alloy in a process called cladding. Important metal coatings from a corrosion prevention standpoint are cadmium, chromium, nickel, aluminum, and zinc.