Stainless steel nuts are made of metal, and metal corrosion protection methods are mainly in four aspects, namely the nature of the material, the environment used, the interface between the data and the environment, and the design of the improved metal structure. If a complete corrosion-resistant alloy is used to make the stainless steel nut. Unless there is a special need, it is not practical in terms of economics, or it can be completely isolated from the appearance of the nut and the environmental elements that will cause corrosion. It may not be feasible in practice, and it may be very difficult. The improved metal structure design can improve the influence of special conditions under certain conditions, but the design of most stainless steel nuts can not be fully corrected, and its maintenance effect, so this method can not basically deal with the problem, as long as the corrosion protection at the interface, that is, the appearance Anti-corrosion treatment is currently widely used.
The anti-corrosion treatment of stainless steel nuts refers to the application of maintenance layers on the metal surface by various methods. The function is to isolate the metal from the corrosive environment to suppress the corrosion process or reduce the contact between the corrosive medium and the metal surface. Avoid or mitigate the purpose of corrosion.
The maintenance layer should be able to meet the following requirements:
1, Corrosion resistance, wear resistance, high hardness,
2. The structure is strict, intact, and the pores are small.
3. It is separated from the base metal and has good adhesion.
4, The average spread and thickness.
The maintenance layer is usually divided into two types: metal coating and non-metal coating. The metal coating refers to the use of a highly corrosion-resistant metal or alloy to form a maintenance layer on the surface of a metal that is easily corroded. This coating is also called a coating. There are quite a few methods and varieties for producing metal plating, among which electroplating is common, followed by molten metal immersion plating (hot dip plating and chemical surface treatment. Non-metallic coating refers to the use of organic polymer materials such as paint, and inorganic materials. Such as ceramics, the maintenance layer is formed on the surface of the metal equipment or parts. The maintenance layer can completely separate the base metal from the environmental medium, and avoid corrosion of the base metal due to contact corrosion in the stainless steel standard medium.