hat is generated at the cathode removes electrons from the cathodic surface. If oxygen is present, electrons are removed from the metal by oxygen reduction. At the anode, a metal ion is released from its structural position through loss of electron bonding and passes into solution( ) (Bertness and Chilingarian, 1983, 560).
The electrical potential that exists between the cathode and anode demonstrates the rate of corrosion. Changing or neutralizing the rate of electrical exchange between these two points is most important. Controlling the amount of oxygen present in these reactions is one way of achieving positive results (Bertness and Chilingarian, 1983, 561). In other words, corrosion as a form of oxidation needs to be understood and then hopefully controlled.
Understanding the electromotive force(emf) series can direct cost and time saving measures. Oxidation takes place when a given substance loses electrons. Reduction occurs when there is a net gain of electrons. A substance that yields electrons is called a reducing agent, whereas a substance that gains electrons is called an oxidizing agent (Bertness and Chilingarian, 1983, 563).
A chart displaying the electromotive and electrochemical potentials of elements indicates iron and nickel, two key ingredients of steel, to be fairly reactive in the presence of hydrogen and oxygen. As a matter of fact, iron and nickel are listed as having a positive electron potential (rate of flow) as opposed to oxygen and hydrogen which show a respective electron flow of negative and neutral. As these substances almost never meet in neutral circumstances, corrosion of some sort is sure to follow (Weast, 1987, F 245).
Dissimilar metals exposed to differences in electromotive forces exhibit different tendencies to go into solution depending on the environment. Coupling of dissimilar metals in an electrolyte will cause destruction of the more reactive metal which will act as an...