Zinc Coating Cr+3 Blue Passivation
Trivalent (Cr+3) blue passivation is an environmentally friendly surface treatment applied after electrolytic zinc plating, characterized by its thin film structure. The passive layer formed increases the corrosion resistance of the zinc coating while maintaining the electrical conductivity and assembly compatibility of the surface.
Compared to Cr+6 systems, this type of passivation offers higher thermal stability and is therefore preferred especially in automotive and fastener applications. It is applied on zinc coatings compliant with the EN ISO 2081 standard and, when used with appropriate processes and topcoat (sealer/lacquer), provides enhanced corrosion performance under ISO 9227 salt spray test conditions.
