Factors affecting the NSS corrosion resistance of trivalent chromium passivation coating on zinc deposit

Factors affecting the corrosion resistance of trivalent chromium passivation coating on Zn deposit were pointed out. The effects of the design of protection level for workpiece surface (thickness of Zn deposit, Zn plating process and operation type), on-site management in production (contamination of Fe ions, accumulation of Zn ions, collision of workpiece and drying temperature) and passivation process parameters (volume fraction of passivator, temperature, pH and immersion time) on neutral salt spray (NSS) corrosion resistance of trivalent chromium passivated Zn coating were discussed. The importance of properly selecting trivalent chromium passivator and on-site management was emphasized.