What is the role of surface passivation treatment of stainless steel extension springs

The surface passivation treatment of stainless steel tension springs is an important technology. Its core lies in forming a dense oxide film on the surface of the spring by chemical or electrochemical methods. This film is mainly composed of chromium oxide (such as Cr₂O₃) generated by the reaction of chromium elements in stainless steel with oxygen, which has extremely high stability and corrosion resistance. The formation of the passivation film is like a solid barrier, which effectively isolates the spring substrate from direct contact with external corrosive media, thereby significantly reducing the corrosion rate and extending the service life of the spring.

Passivation treatment plays a key role in many aspects. First, it significantly enhances the corrosion resistance of stainless steel tension springs. During use, springs are often exposed to harsh environments such as humidity, high temperature, strong acid and alkali, which pose a high risk of corrosion to springs. Through passivation treatment, the dense oxide film formed on the surface of the spring can effectively resist the erosion of these corrosive media, thereby ensuring the stability and reliability of the spring in extreme environments.

Secondly, passivation treatment improves the surface hardness and wear resistance. The passivation film not only has excellent corrosion resistance, but also can improve the hardness and wear resistance of the spring surface to a certain extent. This effect is due to the close bonding between the passivation film and the spring matrix, as well as the density and hardness of the film layer itself. During friction and wear, the passivation film can effectively reduce the damage to the spring surface, thereby extending its service life.

In addition, the passivation treatment significantly optimizes the appearance and improves the texture. The surface of the stainless steel tension spring after passivation presents a uniform and bright silver-white luster, which not only improves the beauty of the product, but also enhances the overall texture. This has a significant market competitive advantage for some application scenarios with high requirements for appearance, such as high-end mechanical equipment and precision instruments.

Finally, the passivation treatment also improves the fatigue resistance of stainless steel tension springs to a certain extent. In the process of repeated stretching and compression, the spring is often affected by alternating stress and is prone to fatigue damage. The formation of the passivation film can effectively reduce the stress concentration phenomenon on the surface of the spring, reduce the probability of fatigue cracks, and thus enhance its fatigue resistance.