The Influence of Surface Preparation on Corrosion Resistance of Organic Zinc-Rich Paint

Abstract

Recently, in Japan, an increasing number of community structures that have been built more than 50 years ago have required appropriate management to maintain their functionality. The painted steel structures are regularly repainted to maintain their corrosion resistance. Excellent corrosion resistance can be achieved by thoroughly removing the rust and residual coating film on the steel surface during surface preparation using either blasting or wire brush treatment. The wire brush treatment is very workable even when there is a problem with corrosion resistance after coating. This research examined surface preparations using three different types of wire brush treatments. Furthermore, the organic zinc-rich paint was applied to steel plates that had undergone different surface preparations, and the corrosion resistance of each painted steel plate was investigated by accelerated corrosion testing. The results demonstrated that the paint sample that was subjected to surface preparation using either a nickel-or zinc-plated steel wire wheel brush exhibited better corrosion resistance than that exhibited by the one subjected to surface preparation using a steel wire wheel brush without plating. This was caused by the difference between the corrosion barrier properties of the zinc-based corrosion product layers that were formed in the painted samples.