U. Harm, W. Fürbeth, K.-M. Mangold
Studies are reported on the formation over zinc-coated steel surfaces, of corrosion-inhibiting mono- and multi-layer films formed from various phosphonic acids/phosphonates as well as certain thio compounds. Following acidic or alkaline pre-treatment, the molecular films both cross-linked and unlinked, were applied to the surface by a short immersion process in a dilute aqueous solution. Contact angle measurements served to confirm the results of such treatments. In subsequent corrosion tests, certain of these films were found to significantly inhibit white rust formation. Additional protection resulted from application of a further organic film applied using an organic immersion sealing procedure.