The ocean is the place with the worst corrosive environment.
The corrosion area of the offshore platform can be divided into: a) marine atmosphere b) splash area c) tidal range d) full immersion area e) sea mud area
The marine coating system includes primers, intermediate coatings and topcoats, and the underwater parts also include antifouling paints.
Primer is based on high anti-corrosion primer. Commonly used primers include epoxy zinc-rich primer, inorganic zinc silicate primer, and epoxy anti-rust primer. Zinc-rich primer is an organic or inorganic coating containing a high proportion of zinc powder as a filler. The epoxy zinc-rich coating uses high-build epoxy coating with a volume solid content of more than 70%, strong adhesion, and surface tolerance.
The function of the intermediate coat and topcoat is to provide a protective layer for the primer, slow down and limit the penetration of water vapor, oxygen and chemically active ions. Commonly used topcoats in the marine offshore platforms include aliphatic polyurethane topcoats and polysiloxane coatings. Aliphatic polyurethane coatings are often used in conjunction with zinc-rich primers and high build epoxy intermediate coat. The polysiloxane coating is directly matched with the zinc-rich primer coating. Epoxy polysiloxane coatings have stronger corrosion resistance, and acrylic polysiloxane coatings are better in decoration property.