ZINC-ALUMINUM ALLOY COATING AND METHOD OF HOT-DIP COATING

摘要

A ferrous metal strip is continuously hot-dip coated by immersing the metal strip in a hot-dip coating bath containing between about 0.2 wt. percent and about 17 wt. percent aluminum, between about 0.02 wt. percent and about 0.15 wt. percent antimony while excluding lead in amounts more than 0.02 wt. percent, and the balance being essentially zinc. Smooth bright coatings are formed which are highly resistant to intergranular corrosion and blistering when exposed for an extended period to a hot humid atmosphere, have good formability in both the as coated state and after prolonged exposure to a hot humid atmosphere, have a markedly reduced susceptibility to the information of white rust, and have a reduced rate of general surface corrosion without any diminution of the mechanical properties of the coating.