The influence of chromium oxide coating weight on filiform corrosion of trivalent chromium coatings for packaging steel

This paper describes a systematic study into the initiation and propagation of filiform corrosion (FFC) on industrially important Cr(III) coatings applied to packaging steel. FFC was initiated by introducing an artificial scribe into a model PVB organic coating which had been applied to the metallic coatings. The FFC corroded area was shown to decrease at increased values of Cr(III) oxide coating weight. This was explained largely due to the insulating properties of Cr(III) oxide. Chloride entrapment within the tail caused filament tapering. FFC was shown not to initiate on traditional electro chromium coated steel (ECCS).