The main methods of metal anticorrosion are as follows. 1, structural change method of metal anticorrosion One of the common methods of metal anticorrosion is to change the structure of metal. There are many kinds of metals. Some heavy metals have low chemical activity and are not easily corroded by other substances. Some metals combined with other metals can effectively improve their corrosion resistance. For example, adding chromium, nickel and other materials to ordinary steel to make stainless steel can achieve better anti-corrosion effect. 2. Protective layer method for metal corrosion protection is the most widely used. This anti-corrosion method is to make protective layers of various materials on the metal surface to isolate the metal products from the external corrosive media, thus achieving the anti-corrosion effect. Metal corrosion protection layer can be formed by brushing, spraying, electroplating, hot plating, spraying and other methods. There are many protective materials for metal corrosion protection, such as oil, paint and other corrosion-resistant nonmetallic materials such as ceramics and plastics. Metal anticorrosion plating and hot dip plating generally use metals that are not easy to corrode, such as zinc, tin, chromium, nickel, etc. Another material for metal corrosion protection is an oxide film formed on the surface of steel, that is, a black ferroferric oxide film, which can also play a role in corrosion protection. 3. Electrochemical protection method of metal corrosion protection The electrical protection method of metal protection is a metal corrosion protection method based on the principle of galvanic cell theory. According to the galvanic cell theory, as long as the galvanic cell reaction causing chemical corrosion can be eliminated, metal corrosion can be realized. Electrochemical protection methods for metal corrosion protection can be divided into anode protection and cathode protection, among which cathode protection is the most widely used. 4. Treatment method of corrosive medium for metal anticorrosion Metal anticorrosion can be completed by treating corrosive medium. This method focuses on eliminating the existence of corrosive medium, that is, keeping the metal machinery dry. For example, often wiping water on machinery, preventing desiccants in precision instruments, and adding corrosion inhibitors to corrosive media all belong to this anti-corrosion method.