How To Deal With Rust Prevention Of Spring Surface?

There are three common spring anti-corrosion methods: electroplating, oxidation and painting. Electroplating is an effective method to obtain the protective layer on the metal surface Spring Main methods of anti-corrosion treatment. It is characterized by good adhesion, fine and compact crystallization, small porosity, uniform thickness and good physical, chemical and mechanical functions. Electroplating includes zinc plating, chromium plating, copper plating, tin plating and nickel plating. The most common application is zinc plating.

The galvanized surface of spring is generally white or colored. Zinc hardly changes in dry air. In humid air or water containing carbon dioxide, white zinc oxide film will be produced, which can play a role of corrosion inhibition. The zinc coating is suitable for use in various atmospheric conditions, but the corrosion resistance of zinc is poor in aqueous solutions containing acid, alkali and salt and in pure marine atmospheric conditions.

Galvanizing is characterized by low cost, simple process and good effect, so it is widely used for anti-corrosion of small and medium-sized springs in the atmosphere. After galvanizing, the spring shall be passivated and dehydrogenated to improve its corrosion resistance and avoid hydrogen embrittlement. In particular, small springs are more prone to hydrogen embrittlement, so special attention must be paid during pickling and electroplating. The oxidation treatment of the spring is also called bluing or blackening. After oxidation treatment, protective magnetic iron oxide is produced on the surface of the spring, with a thickness of about 0.6~2um. Due to thin film and many voids, the protection ability is poor. Therefore, oxidation treatment can only be used for corrosion prevention of springs working in medium with low corrosivity.

Because of the low cost of oxidation treatment, simple process formula, high production efficiency, and no impact on the characteristics of the spring, it is widely used for surface corrosion prevention of cold formed small springs. In addition to oxidation treatment, there is also phosphating treatment. The phosphating film is stable under atmospheric conditions. Its corrosion resistance is 2-10 times higher than that of oxidation treatment. Painting is also one of the main methods for spring corrosion prevention. Most of them are used in large and medium-sized springs. Especially hot formed spring and plate spring. The paints used for springs mainly include asphalt paint, phenolic acid paint and epoxy paint. For some important springs, in order to improve the adhesion and anti-corrosion ability of the paint, the process of phosphating before painting is also adopted. The commonly used painting methods are painting and dipping. With the development of technology, new processes such as electrostatic spraying will be promoted to improve work efficiency, paint utilization and paint quality.