Degradation of Metals
Corrosion
Deterioration of metals due to the reaction with the environment.
All corrosion reactions are electrochemical in nature.
Electrochemical reactions
Pair of reactions in which electron transfer occurs from one reaction to another.
Oxidation
The reaction where an electron is released. Aka. anodic reaction.
Reduction
The reaction where an electron is consumed. Aka. cathodic reaction.
Electrodes
Anode
The site at which oxidation takes place.
Cathode
The site at which reduction takes place.
Standard Electrode Potential
Measure of a metal’s ability to work as a anode or cathode. Measured in
reference to hydrogen. Denoted by
Electrochemical series
A series of pure metals in the order of their standard electrode potential. Alloys and other materials are not listed.
Cell
When 2 electrodes are electrically connected. The metal with the least
Cell potential
Absolute difference between the 2 electrode’s standard electrode potentials.
Denoted by
For a corrosion reaction to occur spontaneously,