When we sell stamped bearings to customers, once the final order is made, the customer will always ask what color did he can choose for galvanizing?Today we will briefly introduce the effects of different colors after galvanizing.

Usually we have a choice of colors before galvanizing, such as white zinc plating, blue zinc plating, color zinc plating, black zinc plating,why are there different colors and what do they do?

In fact, these are the differences caused by the difference in the passivation process after galvanizing. Different passivation solutions get different color passivation films, and their corrosion resistance will be different, so there are different technical titles.

The color of the galvanized layer is determined by the passivation process, including silver white, blue and white, color (multicolored, army green) black and other processes.

After passivation of the zinc plating layer, passivation films of different colors or white passivation films are usually obtained depending on the passivation solution used. The corrosion resistance of the rainbow-colored passivation film is more than five times higher than that of the colorless passivation film. This is because the rainbow-colored passivation film is thicker than the white passivation film; on the other hand, when the surface of the rainbow-colored passivation film is scratched, the hexavalent chromium in the passivation film near the scratched part will be rubbed in the moist air. The injured part undergoes a "re-passivation" effect to repair the damage and restore the integrity of the passivation film. Therefore, galvanizing mostly adopts iridescent passivation. The colorless passivation film has a white appearance, and is mostly used in products that require a uniform white surface, such as household metals and construction hardware.

The difference in corrosion resistance of white zinc plating, blue zinc plating, color zinc plating and black zinc plating:

The corrosion resistance of zinc plating has the order of strength to weakness: Army green passivation>black passivation>color passivation>blue & white passivation>white passivation