Hot-dip zinc coatings - A comparative study: Part II

Abstract

Hot dip coating is one of the oldest methods for coating on the metals. The demand tor zinc coated steel sheet has risen in recent years due to an increase in the use of zinc based coatings for corrosion resistant applications in the construction, automotive and domestic appliance industries. Zinc coatings provide cosmetics, perforation and general atmospheric corrosion protections against aggressivc environmental conditions. Comparative characteristics studies were done by physical and chemical analysis of zinc coated materials obtained from different sources. Several techniques were used to characterise by coatings, such as EDAX for elemental analysis, thickness measurements using SEM and evolution of corrosion resistance of galvanised sheets in a salt spray, sulphur dioxide and immersed in 5M sodium hydroxide solution. It was found that SC type of samples produced the best coating in the environmcnt of marine and industrial pollution of sulphur dioxide hut in sodium hydroxide environment, it was not best.