Stainless steel joints are made of metal. There are four main methods of metal corrosion protection, namely the nature of the material itself, the environment in which it is used, the interface between the material and the environment, and a plan to improve corrosion. It would be impractical from an economic concept to use alloys that do not lack corrosion resistance to make stainless steel joints, unless there is a specific need, or the appearance of the stainless steel joint would be completely isolated from the corrosive environmental elements.

In practice this may not be feasible and can be very difficult. Improved metal structure planning can be improved under certain conditions to improve the impact of special circumstances, but most stainless steel joint planning can not be completely modified, and its protection is very large, so this method basically can not solve the problem, as long as the metal corrosion interface, that is, the appearance of corrosion protection treatment is now widely used methods.

Anti-corrosion treatment of stainless steel joint surface refers to the use of various methods to apply a protective layer on the metal surface. Its function is to isolate the metal from the corrosive environment to prevent the occurrence of corrosion, or to reduce the contact between corrosive media and the metal surface. The intention of avoiding or mitigating corrosion.

The protective layer should be able to meet the following requirements:

1. corrosion resistance, wear resistance, high hardness

2. Tight structure, no defects, small pores.

3. Firm and strong adhesion to the base material.

4. Evenly distributed and thick.

The protective layer of stainless steel joints is usually divided into two types: metallic coating and non-metallic coating. Metal coating refers to the use of metals or alloys with strong corrosion resistance to form a protective layer on the surface of corrosion-prone metals. This kind of coating is also called plating.

There are many methods and varieties of metal coatings. Among them, electroplating is the commonly used method, followed by molten metal dip plating (hot dip plating and chemical surface treatment. Non-metallic coating refers to the use of organic polymeric materials, such as paints and inorganic materials), such as ceramics, to form a protective layer on the surface of a stainless steel joint or part, which insulates the base material from environmental media and prevents corrosion of the stainless steel joint due to contact with standard stainless steel media.