Last modified: 2016-12-08
Abstract
Hot dip galvanizing is commonly used to protect steels used in civil infrastructure against corrosion. An alternative to hot-dip galvanizing is a cold galvanizing process, which is basically a zinc rich-based organic paint. The cold galvanizing paints are economical, offer similar corrosion resistance as that of hot galvanized zinc coating and are easy to apply. Although, cold galvanized steels offer sufficient and comparable protection against atmospheric or aqueous corrosion, but there is a strong need to explore their corrosion protection ability in underground infrastructure, in particularly, soils which comprise of many different organic compounds. In this study, cold galvanized steels were studied in various organic solvents commonly found in soils, to evaluate their corrosion protection ability in soils. A commercially available zinc rich paint was coated on steel substrates and their corrosion behavior was studied in solutions of humic acid, citric acid, dextrose and oxalic acid by potentiodynamic polarization tests. It was found that citric acid is the most corrosive for cold galvanized steels and the oxalic acid provided sufficient barrier against corrosion. The comparison of results of cold galvanized coating with hot galvanized coatings published previously suggests that cold galvanized coating is equally effective as that of hot galvanized coating.