HiCorP^® is a new passivation process sequence based on Cr (III) in order to give a black conversion coating on electroplated zinc. This process is especially developed for the improved corrosion resistance required by the automotive industry.   When used under recommended conditions, the combination of HiCorP^® BKA with HiCorP^® BKB along with Topcoat BK and Topcoat CL 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