Industrial Methods of Preventing Galvanic Corrosion: Part I
Galvanic corrosion, or bimetallic corrosion, can be prevented by many industrial processes, such as galvanization, cathodic protection, and anodic protection. The rusting of steel and iron can be controlled by coating them with zinc. This process is called galvanization. A hot-dip-galvanized steel strip is often referred to as galvanized iron. It is mainly used for applications that need the strength of steel, combined with the corrosion resistance of zinc. Batch galvanizing is hot-dip galvanization in which individual metal articles are galvanized. For example, wrought iron gates can be galvanized by batch galvanizing. For a steel surface, hot-dip galvanization is selected. In this case, the zinc film coated on steel is thick. Usually, automobile bodies are given decorative coatings. The process of galvanization of ferrous metal surfaces is called “sherardizing.” It involves thermal diffusion galvanizing. Construction steel is the most common use for galvanized metal, and annually, hundreds of thousands of tons of steel products are galvanized around the world.