Properties of Zinc-Zinc Chloride Composite Electroplated Steel Sheets

Abstract

Zinc-zinc chloride composite electroplated steel sheet was studied; the study was done since basic zinc chlorides are stable compounds in chloride environment. Zinc-zinc chloride composite layer was electro-deposited on steel in 3M ZnCl₂ bath, in which colloid of 4Zn(OH)₂.ZnCl₂ was suspended. The amount of codeposited colloid increased with bath temperature, whereas the crystal grain size, distribution and thickness of deposited metallic zinc became less uniform with increase in bath temperature and current density. The plating condition of 40°C-20A/dm² increased uniformity of zinc-zinc chloride composite layer and thereby enhanced its corrosion resistance.