sacrificial anodes???

Question

how do these things work? i dont get it. how can objects redirect corrotion

Answer 1

As in the previous reply, the zinc will corrode first because it has a lower oxidation potential. And yes it will protect the steel until most of the sacrificial anode is gone. One other thing to mention is that there is a limited area in which the anode will protect the steel. That is you can't put just one sacrificial anode in a tank or vessel and expect to protect 100 percent of the steel. Therefore, the sacrificial electrodes are spaced throughout the tank for vessel to provide uniform protection to the steel.

The exact spacing is something that a metallurgist can calculate.

Answer 2

A sacrificial anode is a piece of readily corrodible metal attached (by either an electrically conductive solid or liquid) to the metal you wish to protect. This piece of metal corrodes first, and generally must dissolve nearly completely before the protected metal will corrode (hence the term "sacrificial").

The sacrificial anode corrodes first because it more easily oxidizes than the protected metal. Electrons are stripped from the sacrificial anode and conducted to the protected metal, protects it from corroding.

Answer 3

Used on Submarines in particular.

The anodes are made of zinc, which believe it or not divert the electromagnetic effect that salt water and steel produce.

As the zinc is a soft metal, it disolves causing oxidisation away from the submarine.