Metals and Some Aspects of Corrosion

Corrosion

is the gradual destruction of materials by chemical reaction with its environment. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen.

Galvanic Corrosion

destroys metallic objects. For this corrosion to occur, several conditions must be present simultaneously. These conditions are:

1. The metal is oxidized at the anode of an electrolytic cell.

2. Some ions are reduced at the cathode.

3. There is a potential (voltage) between the anode and cathode.

4. An electrolyte must be present

5. The anode must be electrically connected to the cathode

Electrolyte

is defined as a chemical substance, usually a liquid, that conducts electricity. Indeed, it can include vapors, and even solids, such as an oxide film. 

Cold Work

breaks large grains into smaller grains, thus producing larger numbers of grains and more grain boundaries. The more boundaries and grains, the greater is the opportunity for corrosion to occur.