Definition - What does Medium mean?
A medium, in terms of corrosion, is an element, solution or compound that serves as an environment for corrosion testing. The reactions of different materials depend on the type of media present. By studying the different kinds of medium along with the reactions of the most common industrial metals, methods for corrosion control and prevention can be accurately determined.
The most typical form of medium includes acidic and basic solutions where metal reacts according to its composition and electrochemical properties.
Corrosionpedia explains Medium
Metals corrode through driving forces that serve as natural consequences of their form. In order to evaluate the corrosiveness of a certain metal in various environments, synthetic mediums are used. Metals corrode depending on the ionic content of aqueous medium.
This can determine how alkaline or acidic a solution is. The excess hydrogen (H) or hydroxyl (OH) define the pH levels of the medium. Hydroxyl ions contribute to the alkalinity of the solution while the hydrogen ions relate to acidity.
Higher pH or acidity means that there are fewer free ions of hydrogen, and a slight change in pH can denote a tenfold change in terms of the hydrogen-ion concentrations. A medium that has a pH below 7 is considered acidic. A medium with low pH or acidity in nature can accelerate corrosion through supplying ions of hydrogen throughout the process of corrosion.
Thus, in most cases, acidic environments are highly corrosive. This can be the case in industrial and mine waters. When using a medium similar to the environment of a particular setting, operators are able to replicate and study situations that can develop into crevices or pitting caused by corrosion.