Galvanizing is a process of coating iron or steel with zinc in order to provide greater protection against corrosion for the iron or steel base. The process of galvanizing sheet iron was developed simultaneously in France and England in 1837. Both of these methods employed a “hot dipping” process to coat sheet iron with zinc. Like tinplate, early galvanized metals were hand dipped. Today almost all galvanized iron and steel is electroplated.
- Galvanized iron and steel’s resistance to corrosion depends largely
on the type and thickness of the protective zinc coating and the
type of corrosive environment.
- The zinc coating on galvanized iron and steel may be corroded by:
Acids, strong alkalis, and is particularly vulnerable to corrosion
by sulfur acids produced by hydrogen sulfide and sulfur dioxide
pollution in urban atmospheres.