Recently corrosion problem of ocean-going vessels becomes to attract strong attention. Especially, the main issue comes from corrosion in the ships' ballast tank. Almost all the ships, in general, adopt the painting protection to prevent corrosion in the seawater ballast tank, but deterioration or damage of painted coating surface causes corrosion of ship's ballast tank. Thus International Maritime Organization(IMO) legislates Performance Standard for Protective Coatings(PSCP), and it comes to enforced from 2008 year. As a result of PSPC, the protection methods on paint coating will be more complicated than before. Moreover, it will be very costly to comply with the strengthened regulation. For this reason, each coating method on ballast tank for corrosion resistance was estimated such as PE(polyethylene), PA(polyamide), pure epoxy, hot-dip galvanized coating(Zn) and hot-dip aluminized coating(Al) and so on.
Consequently, considering an actual state, this paper intends to present a basic guide line to design and installation by analyzing and forecasting corrosion tendency and rate of all the coating materials.
From the result of this study, conclusion are as follows.
-. P.E(polyethylene), P.A(polyamide), pure epoxy showed superior properties to hot-dip galvanized coating(Zn), hot-dip aluminized coating(Al) whenever defect like scratch, desquamation and deterioration didn't occur. And then, P.E. and P.A, which relatively have good adhesion properties, showed better corrosion resistance than pure epoxy when Fe base metal is exposed in seawater environment locally by damaged coating surface such as scratch, desquamation or deterioration.
-. Hot-dip galvanized coating(Zn) and hot-dip aluminized coating(Al) had a sacrificial effect for Fe, which play a role to protects and keep up base metal for the time being accordance with time, environment and thickness of sacrificial anode.
Through the comparison and analysis of coating materials for ballast tank, tendency of corrosion resistance properties was investigated. In the future, proper application of above mentioned coating methods should be recommended for the protection of ballast tank in seawater environment.