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Nwankwo Ekene

What is the difference between galvanization and sacrificial protection?

Connor Leech  Follow

Galvanising is coating the iron with a layer of zinc in order to prevent it from rusting. However, sacrificial protection is attaching a piece of zinc to the iron object.Both methods use the same principle to work. Even if the iron is exposed to water or oxygen in the air, the water and oxygen react with zinc, as it is more reactive.

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Dave Smith  Follow

In galvanisation, zinc is coated on the surface of iron to prevent it from corroding.But sacrificial protection is the process where zinc is kept near iron surface so that zinc corrodes instead of iron. Here, zinc is not coated on iron's surface.

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Bert Murray  Follow

No difference ; the zinc corrodes preferentially providing protective current/potential to the iron/steel. Although anodes can be a distance away from the steel if they are immersed in a conductive media. Also , anodes can be replaced MUCH easier than replacing a zinc coating.

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Billy Chang  Follow

They are used in different media. Galvanization is used to protect iron exposed to non-corroding medium (air), while sacrificial electrodes are used to protect iron in electroconductive and corrosive medium (sea water or moist soil).

Protective zinc oxide layer on galvanized surface is desired to stay undisolved, while the purpose of sacrificial electrode is to keep being oxidized to assure electron flow to other metal surface. In latter case medium electrconductivity is a must for ion transfer process, while corrosivness is needed for oxidized zinc surface layer disolution.

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