Galvanizing

Galvanizing is the process by which a coating of zinc is applied on a metallic generally of steel to protect against galvanic corrosion : in fact it limits the formation of micro- electrolytic cells to action in the anodic grain boundaries .
Zinc is less electronegative ( less noble ) of the steel , and then , in case of breakage or porosity of the protective film , it itself becomes the sacrificial anode in the electrolytic corrosion and is consumed if there is closure of the field lines .
The galvanizing process can take place in these methods :
hot dip galvanizing ;
continuous hot-dip galvanizing .
zinc plating ;
cold galvanizing ;
galvanizing spray .
Care must be taken to the fact that facilities performing heat treatments are called galvanization while those are called galvanic zinc plating . The addition of nickel in the merger, in small, precise doses , causes a considerable lowering dell'applicato on steel treated (but then still ensure the absorption minimum governed by the rules of the sector) . The replacement of lead present in the galvanizing bath with bismuth (low - melting ) preserves us from an early pollution of the planet, while preserving the protective qualities of galvanizing and our health.