Atmospheric Corrosion Behavior of Zinc and Zinc Alloys

Zinc atmospheric corrosion is well-known, and standards are available. In some applications, like gabion walls, Zn-Al alloys coatings have been proposed to protect steel wires, together with polymeric top coatings in aggressive environments. The aim of this article is to compare corrosion rates of Zn and Zn-Al coatings exposed to natural atmospheres with ISO standards prediction and accelerated tests. The corrosion rate of zinc alloys is lower than zinc, in both natural and accelerated exposure. The lack of medium-long term data in natural exposure makes it difficult to forecast actual behavior of zinc alloys, especially in more severe exposure conditions.