Coating Protection Against Atmospheric Corrosion for Iron and Steel Structural Components: Status of Metallization in Japan

Low-velocity oxyfuel-spray and arc-spray coatings of Zn, Zn-Al, Al, and various Al-Si and Al-Mg alloys were tested in immersion and salt-spray conditions with artificial sea water for up to 6,000 hours. Coatings were tested as-sprayed or sealed with fluorocarbon, epoxy or silicone sealants. Comparison and overview of coatings recommended by international and Japanese standards are considered. Coatings Al 99.8 outperformed Zn 99.9 and Zn-13A1 ones while Al-(2.5~5.2)Mg and Al-(5~6)Si showed better corrosion resistance than Al 99.8 coatings. The silicone sealant offered better resistance than fluorocarbon and epoxy organic sealants.