Device for in situ monitoring of corrosion rates of polarized or unpolarized metals
US5006786A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 1990 |
| Grant date | Apr 9, 1991 |
| Priority date | — |
| Expiry date | May 3, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23F13/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A technique for electrochemical measurement of the corrosion current (corrosion rate) determines the electrochemical parameters that are necessary to calculate the corrosion rate as they are contained in the harmonic current response to a moderate amplitude sinusoidal voltage perturbation applied to the corroding metallic component. The harmonic current response is analyzed at frequencies .sub.1 f, .sub.2 f, .sub.3 f, .sub.4 f, .sub.5 f and the rectification current response of DC current to the presence of a 20-50 mV AC voltage perturbation at a frequency f. The free corrosion current density, the free corrosion potential and the Tafel coefficients are calculated. The Tafel coefficient or Tafel slope is a measure of the exponential dependence at the rate of corrosion in a material. From these data, the dissolution current is calculated, which in turn is integrated with respect to time to yield a cumulative mass loss.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.