Springs are commonly used in our daily lives, but chemical and electrochemical reactions can lead to varying degrees of corrosion on the spring surfaces, causing damage to the springs and affecting the performance of the equipment. How can we prevent premature corrosion of springs?
There are three methods for preventing corrosion of springs: painting, oxidation, and electroplating. The principle of their corrosion prevention is to form a protective layer on the surface of the spring, isolating it from the outside environment to achieve the purpose of corrosion prevention.
Painting:
Applying a protective coating to the surface of the spring is one of the primary methods for spring corrosion prevention. This method is commonly used in large and medium-sized springs, particularly for heat-formed springs and leaf springs. The usual methods for painting are spray painting and dip painting. With the development of technology, to enhance work efficiency, paint utilization, and the quality of the coating, the promotion of new techniques such as electrostatic spraying will be implemented.
Section II: Oxidation Treatment
The oxidation treatment of springs, also known as bluing or blackening, results in the formation of a protective magnetic ferric oxide layer on the spring surface, with a thickness of approximately 0.6~2um. Due to its thinness and porous nature, the protective ability is relatively poor. Therefore, oxidation treatment is only suitable for corrosion-resistant springs operating in media with low corrosion.
Due to its low oxidation treatment cost, simple process formula, high production efficiency, and no impact on the characteristics of springs, it is widely used for surface corrosion prevention of cold-formed small springs.
III. Electroplating:
Electroplating is an effective method to obtain a protective layer on metal surfaces and is primarily used for spring corrosion treatment. It is characterized by good adhesion of the coating, fine and dense crystalline structure, low porosity, even thickness, and excellent physical, chemical, and mechanical properties.
Plating includes zinc, chrome, copper, tin, and nickel coatings, with zinc plating being the most commonly used. The surface of zinc-plated springs is typically white or colored. Zinc remains almost unchanged in dry air. In humid air or water containing carbon dioxide, it forms a white zinc oxide film, which acts as a corrosion inhibitor.
Galvanized coatings are suitable for use under various atmospheric conditions, but their corrosion resistance is poor in solutions containing acids, alkalis, salts, and in pure marine atmospheres. The features of galvanizing include aesthetics, low cost, simple process, and good effectiveness, thus it is widely used for corrosion prevention of small and medium-sized springs in outdoor applications.
