galvanizing, process of coating a metal, usually iron or steel, with a protective covering of zinc. Galvanized iron is prepared either by dipping iron, from which rust has been removed by the action of sulfuric acid, into molten zinc so that a thin layer of the zinc remains on the surface of the iron upon removal or by a method of electroplating. Iron is also coated with zinc by a method in which the iron is first covered with the zinc dust and then baked; an alloy is formed at the surface, the resulting product being known as sherardized iron. Sheets of pure iron, copper iron, and various steels, as well as wire and netting, are often galvanized, since the zinc coating resists oxidation and the action of moisture very successfully. When the coating is broken or pierced some protection is still afforded, since the zinc reacts with the corroding agent first.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.