The basic function of spring galvanizing

Why do springs need surface treatment? What needs to be done after surface treatment? What is the role of galvanizing? I believe you have not found a suitable answer after seeing these questions. Generally, people think that galvanizing is just for appearance, but we don`t know. Galvanizing has other functions besides being beautiful.
1. Why do springs need to be galvanized?
(1) Generally, the galvanized layer is passivated after plating. Passivation can improve the protective function of the coating and increase the appearance of the surface.
(2) The thickness of zinc and cadmium coating determines the level of protection ability. The thickness should generally be selected according to the operating environment during use. The thickness of the galvanized layer is recommended to be selected within the range of 6~24/μm; the thickness of the cadmium plated layer is recommended to be selected within the range of 6~12/μm.
(3) The zinc plating and cadmium plating of springs are carried out in cyanide electrolyte. During the electroplating process, in addition to plating zinc or cadmium, a part of the restored hydrogen enters the lattice of the coating and the base metal. , forming internal stress, making the coating on the spring and the spring brittle, also called hydrogen embrittlement.
(4) Due to the high strength of the spring material and the large deformation during the forming of the spring, it is particularly sensitive to hydrogen embrittlement. If the hydrogen is not removed in time, it will often cause the Stainless Steel Spring to crack. In order to eliminate the hydrogen embrittlement that occurs during the electroplating process Some shortcomings include improving the physical and chemical properties of the spring, extending the service life of the spring, and improving the corrosion resistance of the coating. It is necessary to perform post-plating treatment, that is, hydrogen removal treatment.
(5) Hydrogen removal treatment is performed immediately or within a few hours after electroplating. The purpose of hydrogen removal can be achieved by heating the electroplated spring at a temperature of 200 to 215°C for 1 to 2 hours (or more than 2 hours).
2. What is the function of spring surface treatment?
(1) There are many types of metal protective layers. As for springs, electroplating is generally used to obtain the metal protective layer. The electroplated protective layer not only protects against corrosion, but also improves the appearance of the spring. Some electroplated metals can also improve the working performance of springs, such as increasing surface hardness, increasing wear resistance, improving thermal stability, preventing radiation corrosion, etc. But if it is purely for spring corrosion, electroplated zinc layer and electroplated cadmium layer should generally be used.

(2) Zinc is relatively stable in dry air, almost unchanged, and not easy to discolor. In humid air, a white film of zinc oxide or zinc carbonate will form. This fine film prevents further corrosion. Therefore, the galvanized layer is used as a protective layer against corrosion of wave spring under normal atmospheric conditions. Any springs that come into contact with sulfuric acid, hydrochloric acid, caustic soda and other solutions, as well as those that operate in humid air such as sulfur trioxide and other atmospheres, are not suitable for zinc coating.