Corrosion protective performance studies of coating systems in soda ash chemical industry

Organic coatings are widely used to protect steel structures. The performance of the coating system depends upon the atmospheric conditions prevailing in the chemical industry. Before selecting a protective system, the corrosivity of the atmosphere has to be determined. A study has been made for selecting a good protective system for a soda ash chemical industry where chemicals such as soda ash, sodium chloride and hydrochloric acid are produced by using sea water as a raw material. Under these conditions, after collecting the corrosivity rate at various places of industrial areas, coated steel panels with various paint combinations were exposed in different sites for a period of 2 years. The performance of the coatings was monitored by EIS studies besides visual inspection. The corrosion protection performance of the various coating systems of zinc rich primer with different types of under coats and top coats has been studied and the results are reported.