5.1.1 Corrosion Definition & Scope
Definition: Corrosion has been defined as:
“The destruction or deterioration of a material because of reaction with its environment.”
Mars G. Fontana
Scope: Corrosion can be characterized as:
Not restricted to metals
Includes ceramics, plastics, rubber, & other non-metallic materials
Can be fast or slow reacting
Depending upon the material all environments can be corrosive
The environment in which corrosion occurs is typically categorized as wet or dry and this difference can have a significant impact upon the corrosion of a metal. For example consider chlorine.
Chlorine, in its natural state is a gas (dry). However, it can also be manufactured into liquid (wet) form. In its gas (wet) form chlorine is normally corrosive to ordinary steel. Yet, in liquid (wet) form chlorine is extremely corrosive to ordinary steel and other common metals.
However, a dry versus wet environment can have unexpected results. For example, when we consider titanium, dry (gaseous) chlorine is far more corrosive than wet (liquid) chlorine.