What Does Potentiodynamic Mean?
Potentiodynamic is a term describing the measured change in the electrical potential (voltage) of a system. In electrochemistry, this term is used in describing polarization methods in the corrosion industry.
Potentiodynamic refers to a polarization technique in which the potential of the electrode is varied over a relatively large potential domain at a selected rate by the application of a current through the electrolyte.
Potentiodynamic polarization is often used for laboratory corrosion testing. It can provide significant useful information regarding corrosion mechanisms, corrosion rate and susceptibility of specific materials to corrosion in designated environments.
Potentiodynamic is also known as potentiodynamic polarization.
Corrosionpedia Explains Potentiodynamic
Potentiodynamic polarization is a technique where the potential of the electrode is varied at a selected rate by application of a current through the electrolyte. This technique is used in polarization of specimens for corrosion testing.
A potentiodynamic polarization variant is cyclic voltammetry, which involves sweeping the potential in a positive direction until a predetermined value of current or potential is reached. Then the scan is reversed toward more negative values until the original value of potential is reached.
Another variation of potentiodynamic polarization is the potentiostaircase method, which is a technique for polarizing an electrode in a series of potential steps where the time spent at each potential is constant, while the current is often allowed to stabilize prior to changing the potential to the next step. The step increase may be small, in which case, the technique resembles a potentiodynamic curve.
Electrochemical potentiodynamic reactivation (EPR) is a polarization method that evaluates the degree of sensitization of stainless steels. This method uses a potentiodynamic sweep over a range of potentials from passive to active (called reactivation).
The most popular variant is the cyclic polarization test. This test is often used to evaluate the pitting susceptibility of a material. The potential is swept in a single cycle or slightly less than one cycle, usually starting the scan at the corrosion potential.
This technique has been especially useful to assess localized corrosion for passivating alloys such as S31600 stainless steel, and other alloys such as titanium and zirconium. Though the generation of the polarization scan is simple, its interpretation can be difficult.