A metal- iron is galvanized to prevent it from rusting. Why doesn't the iron get rusted, even after removing the coating of zinc?
A metal- iron is galvanized to prevent it from rusting. Why doesn't the iron get rusted, even after removing the coating of zinc?
The layer of zinc on the surface of the metals coated prevents other elements from reaching the metal so quickly. It also develops a patina (a layer of zinc oxides, salts, and other compounds) that offers further protection. If the outer layer of metal which is galvanized is subjected to scratch or damage, the material is getting coated with a stronger layer of basic zinc carbonate, and thus is able to resist corrosion. Thus the outer layer also protects the metal by acting as a “sacrificial layer”.
Hence even after removing the coating of zinc on galvanized iron, the sacrificial outer layer formed by zinc around the iron, will corrode first by protecting the iron surface from corrosion. Thus the galvanized iron does not get corroded and can last more years without maintenance under average conditions.
The layer of zinc on the surface of the metals coated prevents other elements from reaching the metal so quickly. It also develops a patina (a layer of zinc oxides, salts, and other compounds) that offers further protection. If the outer layer of metal which is galvanized is subjected to scratch or damage, the material is getting coated with a stronger layer of basic zinc carbonate, and thus is able to resist corrosion. Thus the outer layer also protects the metal by acting as a “sacrificial layer”.
Hence even after removing the coating of zinc on galvanized iron, the sacrificial outer layer formed by zinc around the iron, will corrode first by protecting the iron surface from corrosion. Thus the galvanized iron does not get corroded and can last more years without maintenance under average conditions.
