The effect of hydrogen charging on the quality of zinc and powder paint coatings

Abstract

There are shown some case studies when the defects in coatings (hot dip galvanised and duplex coatings with powder paints) were caused by hydrogen charging into matrix of substrate steel. Steel was exposed into hydrochloric acid and then the zinc coatings had been formed at higher temperature. The evidence of hydrogen recombination and its molecules ́ diffusion from coating layers is shown on cross-sections. The hydrogen release caused the defects on subsequently powder coated galvanized plates, too.