6: Wet Corrosion

Wet Corrosion is the most common form of corrosion.

It will occur if an “electrochemical cell” is produced.

An electrochemical cell consists of an Anode, a Cathode, a Connection, and an Electrolyte.

Click on the links below to see the construction of an electrochemical cell.

The anode is the metal that corrodes. It undergoes oxidation and therefore loses electrons.

The cathode can be a metal or any other conducting material. It undergoes reduction and therefore gains electrons. The reaction that occurs at the cathode is not necessarily related to the material that it is made from.

The connection is necessary for the electrons to travel between the anode and cathode and can be either physical direct contact or some form of wire.

An electrolyte must also be present to allow for migration of ions between the cathode and anode and participate in the formation of corrosion products.

 

 

Wet corrosion therefore involves an oxidation reaction at the anode and a reduction reaction at the cathode.

In the oxidation reaction metals give up electrons to become positively charged ions.

The electrons generated from the metal are transferred to another material. This is the reduction reaction and occurs at the cathode.