HiCorP^® is a new passivation process sequence based on Cr (III) in order to give a thick conversion coating on electroplated zinc as well as aluminium and its alloys. This process is especially developed for the improved corrosion resistance required by the automotive industry.   When used under recommended conditions, the combination of HiCorP^® ZNA with HiCorP^® ZNB along with Sealer 615 results in a salt spray life of around 240 hours (5% white rust) for pure zinc electrodeposits. The time taken for red rust formation is comparable to that of zinc-aluminium flake coatings or zinc-nickel electrodeposits.