Definition - What does Corrosion Potential mean?
The corrosion potential of a given material is the electromotive force or the voltage conducted by its surface. This is determined by immersing the material and a reference electrode in an electrolyte, causing the material's surface to release electrons.
Corrosionpedia explains Corrosion Potential
In simple terms, corrosion potential is the characteristic or property of metal and nonmetal surfaces to lose electrons in the presence of an electrolyte. During the process of corrosion, two electrodes are formed spontaneously, a cathode and an anode. Corrosion potential is the electrode potential that the material surface acquires automatically in its environment.
The corrosion potential of a material is a useful parameter in estimating the present and future corrosion damage and detection, as well as monitoring the electrochemical reaction causing corrosion, both at the work site as well as in the laboratory. Hence, the study of this variable is important for designers of pipelines, equipment, systems as well as structures, and also for maintenance engineers in order to reduce economic losses due to material deterioration and its detection expenses, costly and high risk failures as well as repair and replacement costs.
Corrosion potential can be measured by finding the potential difference between an appropriate reference electrode and the material's surface, usually a metal surface, when immersed in a given electrolyte. This measurement is done by using a high impedance voltmeter with high accuracy to observe and record small voltages without requiring significant current flow. A higher current flow can affect the accuracy of the voltage measurement. Measurement of corrosion potential is used in evaluation of effectiveness of protective coating on pipelines and other equipment, as well as structures. It also enables detection of defects in the coated surfaces, such as pinholes, lack of adhesion and porosity.