Benchmarking of Zinc Coatings for Corrosion Protection: A Detailed Characterization of Corrosion and Electrochemical Properties of Zinc Coatings

Abstract

Due to various types of Zn coatings for many decades for various applications, it is imperative tostudy and compare their corrosion resistance properties of some of these. Here, we introduce a systematicmethodology for evaluation and validation of corrosion protection properties of metallic coatings.According to this methodology, samples are were exposed in an advanced cyclic corrosion test chamberaccording to ISO 14993, and removed at the end of each withdrawal for respective corrosion andelectrochemical characterization to evaluate both barrier and galvanic protection properties. Corrosionprotection properties of coatings were evaluated by visual examination according to ISO 10289, massloss and subsequent corrosion rate measurements, electrochemical properties, and advanced electrochemicalscanning techniques. In this study, corrosion protection properties of a commercial zinc rich coating(ZRC) on AISI 1020 mild steel substrates were evaluated and benchmarked against hot dip galvanized(HDG). Results were correlated, and corrosion protection capabilities of the two coatings were compared.The zinc rich coating performed better than hot dip galvanized coating in terms of overall corrosionprotection properties, according to the exposure and experimental conditions used in this study. It provedto be a suitable candidate to replace hot dip galvanized coatings for desired applications.