Effect of double layer structure on the determination of corrosion rates from polarization measurements
The effect of the double layer structure is very seldom considered in the electrochemical measurements of corrosion rates. Polarization equations of corroding metals can be corrected for the effect of the double layer using the classical Frumkin correction of electrode kinetics. This corrected polarization equation can be used to generate synthetic data which, in turn, permit the calculation of the error caused by the neglect of the double layer effect in the electrochemical corrosion rate determinations. While the error depends on many parameters, the two dominating factors are the concentration of the solution and the potential of the corroding metal with respect to the potential of zero change (pzc). The error will be negligible (less than ten percent) if the solution concentration is at least 0.1 molar or the corrosion potential is at least /+-/0.25 V from the pzc. The error can be very large, many hundreds or thousands of percents, unless at least one of the above conditions is met, and the appearance of the polarization curves will have no clear indication of the unreliability of the measurement. Under these conditions, the electrochemical measurements should be supplemented with other types of corrosion rate determinations, or a correction can be made if the double layer parameters are known. 5 refs., 4 figs.
- Research Organization:
- Argonne National Lab., IL (USA)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 5028688
- Report Number(s):
- CONF-880549-2; ON: DE88010097
- Resource Relation:
- Conference: Electrochemical Society spring meeting, Atlanta, GA, USA, 15 May 1988
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of diffusion layer structure on the determination of corrosion rates from DC transient measurements
Accelerated corrosion of stainless steel in thiocyanate-containing solutions
Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CORROSION
MEASURING METHODS
CURRENT DENSITY
ELECTROCHEMISTRY
ELECTRODES
ERRORS
LAYERS
METALS
POLARIZATION
CHEMICAL REACTIONS
CHEMISTRY
ELEMENTS
360105* - Metals & Alloys- Corrosion & Erosion
400400 - Electrochemistry