Abstract
Cathode surface area and its ability to reduce oxygen controlled the rate of zinc dissolution and paint delamination from cut edges of hot dip galvanised steel sheets. Zinc corrosion products deposited on steel in atmospheric exposure conditions inhibited oxygen reduction decreasing galvanic current and zinc dissolution and paint delamination. The opposite effect was observed for iron corrosion products. The initial steel substrate and zinc coating thicknesses affected the availability of zinc ions for formation of the protective film.