Corrosion Resistance of Zinc Coated Steel in Sea Water Environment

Résumé

The life time of metallic materials used in naval transport industry is influenced by their corrosion resistance. For utilization in shipbuilding and offshore construction, metallic materials need to be covered with protective coatings, especially, or different anti-corrosion protection methods need to be used. During the last decades a series of inorganic and organic coatings was developed. Among inorganic coatings, the most used ones are the galvanizing treatments. This paper presents a comparative investigation regarding the corrosion resistance of uncoated low alloy steel and galvanizing steel. Both samples have been subjected to corrosion in sea water harvested from the Black Sea, Mangalia harbor. The electrochemical assays were: open circuit potential (OCP), linear polarization resistance (Rp), potentiodynamic polarization (PD) and cyclic voltammetry. The results obtained by in situ determination were confirmed by optical microscopy. The results revealed an improved corrosion resistance of galvanized steel in natural sea water in comparison with low alloy steel.