Marine Corrosion Law of Epoxy Coatings Modified by Nano-SiO₂

The solvent-free epoxy heavy duty coatings with the patent formulation of our laboratory were used as the basic carrier for nano-SiO2,9 cyclical sea simulation tests were performed in order to study the corrosion laws of the nano-hybrid coating/steel samples hanged in different zones of marine environment such as atmospheric zone,splash zone,tidal zone and immersion zone,and then the potentiodynamic polarization curves were tested to prove the test results.The results showed that the corrosion current density in the air-sea interface zone was 5~10 times of that in the immersion zone.The corrosion rate was primarily controlled by cathodic reducing reaction.The general corrosion mainly took place in the atmospheric and immersion zones,but the pitting corrosion appeared in the splash and tidal zones.