A study was undertaken to demonstrate that the corrosion resistance of zinc phosphate coatings can be established by cyclic voltammetry (CV). The height of the anodic current peak at ∼ −800 mV is related to (1) the porosity of the coating and (2) the extent of anodic dissolution of iron and/or zinc phosphate. Scanning electron microscopy (SEM) on the working electrode before and after CV revealed the loci of the corrosion. A good correlation between the accelerated salt spray test and the CV-SEM method was observed. The latter is a much faster (20 to 30 min vs 600 to 3000 h) and highly reproducible corrosion test; thus, it provides a suitable, novel measure of corrosion.

This content is only available as a PDF.
You do not currently have access to this content.