Why Metals experience Corrosion?
Why Metals experience Corrosion?
Corrosion can be defined as the destructive attack
of a metal through interaction with its environment.
Metals experience corrosion because they react with the environments, condensed water or rainwater for example, and corrodes.
Every metals can experience corrosion if placed in contact with the "right" fluid; even stainless steel grades can corrode if placed in contact with some acids or seawater. (see stainless steel corrosion)
Four conditions must exist before electrochemical corrosion can proceed and metals experience corrosion:
(1) there must be a metal,
the anode, where the oxydation reaction, corrosion, takes place.
(2) there must be a cathode, where the reduction reaction takes place
(3) there must be continuous conductive liquid path (electrolyte), for example:
water, seawater, condensing water, humidity..
(4) there must be a conductor to carry the flow of electrons from the anode to
the cathode the meta itself).
The image below show the corrosion process of a metal, iron, exposed to water.
see also:
|
|