Silicon-induced destabilization of galvanized coatings in the sandelin peak region

The excessive reactivity in galvanizing of steels containing silicon has been studied for many years, but a fundamental understanding of the phenomenon is still lacking. The present work was done to show the effect that Γ, the most iron-rich phase in the Fe-Zn system, has on the reaction kinetics. It was shown that the onset of reactive coating formation is coincident with Γ destabilization. The instability was observed in both solid state and solidliquid interactions. The metallographic results and the implications of such an instability will be presented.