Material corrosion is widespread in all areas of people's economy and life. The damage caused by corrosion is very huge, causing material damage and premature scrap. According to statistics, in developed countries, the direct losses caused by metal corrosion each year can account for 4% of the gross national product, and the indirect losses are even greater. Corrosion is a complex phenomenon. There are no fixed patterns and laws. Materials of various structures have their own characteristics when corroded by the corrosive medium. The end result of corrosion is highly variable.