Galvanized iron wire is very common in practical application, some people think that galvanized iron wire will not rust, in fact, it is not. Metal corrosion is caused by the chemical or electrochemical action of the surrounding medium. According to different media, it is divided into atmospheric corrosion, soil corrosion, seawater corrosion, bacterial corrosion and so on. Atmospheric corrosion is more common, because metal products in the process of processing, transportation and storage, when in contact with the atmosphere, there are always atmospheric corrosion conditions.