US3631338A
Expired / Lapsed
US
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Method and apparatus for determining galvanic corrosion by polarization techniques
Assignee: United States Department of the Interior
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Filing: 1969-06-30
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Granted: 1971-12-28
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Expires: 1989-06-30
Abstract
Abstract A specially modified, two-electrode polarization probe is used to detect the onset of and qualitatively measure nonuniform or pitting corrosion of the galvanic type. Each probe electrode consists of a galvanic couple formed from two dissimilar metals in physical and electrical contact; one of the metals acting as an anode portion and the other acting as a cathode portion. Anode to cathode area ratio and total exposed surface areas of the two electrodes are substantially equal.
Inventors
- 👤 Vincent F Fitzpatrick
- 👤 Russell B Richman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:42
CPC Classifications
G; G01; G01N; G01N17/00; G01N17/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
36 words
The device of claim 1 wherein said electrical means comprise means for impressing a known potential across the electrodes and measuring means to determine magnitude of current flow across the electrodes resulting from the impressed potential.
Claim 2
Dependent Claim
19 words
The device of claim 1 wherein the galvanic couple comprises an anode portion mechanically attached to a cathode portion.
Claim 3
Dependent Claim
19 words
The device of claim 1 wherein the galvanic couple comprises an anode portion metallurgically bonded to a cathode portion.
Claim 4
Dependent Claim
25 words
The device of claim 1 wherein the galvanic couple comprises an electroplate of one metal over a portion of the surface of a dissimilar metal.
Claim 5
Dependent Claim
117 words
A process for detecting the onset and qualitatively determining the intensity of galvanic corrosion which comprises: a. immersing a pair of electrodes in a fluid contained within a test environment, each of the electrodes comprising a galvanic couple, both electrodes having substantially equal surface areas and having substantially the same anode to cathode area ratio; b. impressing an electrical potential of known magnitude and polarity across the electrodes and measuring a first current flow generated thereby; c. impressing a second electrical potential having equal magnitude but opposite polarity across the electrodes and measuring a second current flow generated thereby, and d. determining the average of and the difference in magnitude between the first and second measured currents.
Claim 6
Dependent Claim
39 words
The process of claim 6 wherein each electrode is formed of an anode portion of one metal and a cathode portion of a dissimilar metal, the anode and cathode portions being in electrical contact to form a galvanic couple.
Claim 7
Dependent Claim
18 words
The process of claim 7 wherein the impressed electrical potential has a value less than about 20 mv.
References Cited (Backward Citations)
US2215213A
Cited
US3436320A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |