We know that compression springs are mostly made of metal, so the surface is prone to rust. Therefore, we have to consider the anti-rust treatment of the spring surface. What are the surface treatments of compression springs? What methods will we use? The following methods can be introduced to you. Compression springs have many surface protection treatments. Generally, gold plating is done to obtain a protective layer of metal.

The electroplated protective layer not only protects the spring from corrosion, but also improves the appearance of the compression spring. Some plated metals can also improve the performance of compression springs, such as increasing surface hardness, increasing wear resistance, improving thermal stability and preventing radiation corrosion. However, in order to prevent the corrosion of the compression spring, zinc plating or cadmium plating should generally be selected.

The thickness of zinc and cadmium plating determines the protection ability. Generally, the thickness should be selected according to the working environment in use. The hardness of the galvanized layer is recommended to be in the range of 6~24 μm; the thickness of the cadmium plating layer is recommended to be selected in the range of 6 to 12 μm. Generally, the galvanized layer of the pressure spring is passivated. It can improve the protective performance of the coating and increase the appearance of the surface. Cadmium is relatively stable and has strong corrosion resistance in the ocean or high temperature atmosphere. It is a compression spring in contact with seawater, and a compression spring used in hot water at 70°C.

The cadmium coating is brighter and more beautiful than the zinc coating, the quality is softer, the plasticity is better than that of the zinc coating, and the hydrogen embrittlement is less, and it is more suitable for the compression spring as the protective layer. However, cadmium is rare and expensive, and the cadmium salt is highly toxic, causing serious environmental pollution. Therefore, its use is restricted. Therefore, most of the compression springs used only in the aviation, marine and electronic industries use cadmium plating as a protective layer.