Thermally sprayed aluminum and zinc coatings for tidal zone cathodic protection of offshore platform pile legs

Sie sind hier: Homepage > Suche

Thermally sprayed aluminum and zinc coatings for tidal zone cathodic protection of offshore platform pile legs

Li, Yantao / Liu, Jianguo / Duan, Jizhou / Hou, Baorong

The performance of thermally sprayed aluminum and zinc coatings in providing effective corrosion protection for steel structures and offshore platform pile legs was analyzed. Aluminum coatings had the advantage of passive film formation that lowers the rate of uniform corrosion. Zinc coatings remained active in most waters, enabling them to provide effective cathodic protection over a period of time. The zinc-aluminum thermal spray coatings combined the electrochemical activity of the zinc coatings and the long-term protection of aluminum coatings. The preparation of the substrate surface was important for corrosion prevention by thermally sprayed metallic coatings. The blasted surface should have a white metal blast appearance with an anchor-tooth surface profile of 50 to 75 micron. It was observed that the most effective protective method was to spray a zinc coating first, then an aluminum coating, and finally sealed the metal coatings with an organic coating.