General vapour-phase galvanizing and duplex coatings

[摘要] General vapour-phase galvanizing produces fully alloyed Fe-Zn coatings on steel by exposing complex-shaped articles to hot zinc vapours in vacuum. This way, the processing temperature can be reduced to 350 degrees C. The growth from the gas phase generates microstructures different than other galvanizing technologies. Changing the temperature of growth produces different microstructures in coatings of similar thickness. Mechanical properties are correlated to these microstructures. The chemical properties and the natural roughness of the alloyed surface provide excellent adhesion of the organic topcoat in duplex coatings on vapour-phase galvanized steel. We have performed salt spray and Kesternich tests. The corrosion resistance of bare coatings and duplex coatings are superior to the one of commercial galvanized and galvannealed steels. The specific protocol making general vapour-phase galvanizing possible is presently named as Epanizing.

[发布日期] 2019-12-25

[关键词] Metal coating;Cathodic protection;Paint coating;Hydrogen embrittlement