Galvanised Material ArcelorMittal South Africa Zinc Surface Treatment ArcelorMittal South Africa offers the following surface treatments to reduce the risk of wet storage staining during transport and storage Passivation Passivation by chromic acid ideally even coatings of 20 to 40 mg/m2 total on both sides is normally applied to all galvanised material In cases where this treatment may interfere with subsequent processing such as