CA1154713A - Electrical connector of tantalum or niobium for cathodic protection system - Google Patents
Electrical connector of tantalum or niobium for cathodic protection systemInfo
- Publication number
- CA1154713A CA1154713A CA000337562A CA337562A CA1154713A CA 1154713 A CA1154713 A CA 1154713A CA 000337562 A CA000337562 A CA 000337562A CA 337562 A CA337562 A CA 337562A CA 1154713 A CA1154713 A CA 1154713A
- Authority
- CA
- Canada
- Prior art keywords
- niobium
- connector
- tantalum
- oxide
- electrical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
- H01R13/46—Bases; Cases
- H01R13/52—Dustproof, splashproof, drip-proof, waterproof, or flameproof cases
- H01R13/523—Dustproof, splashproof, drip-proof, waterproof, or flameproof cases for use under water
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
- H01R4/58—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation characterised by the form or material of the contacting members
Landscapes
- Prevention Of Electric Corrosion (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Parts Printed On Printed Circuit Boards (AREA)
- Filters And Equalizers (AREA)
- Graft Or Block Polymers (AREA)
Abstract
Abstract Treatment of Metal The use of niobium or tantalum treated in a manner known per se by pickling and anodisation as a connector in a saline solution. Also an electrical connector formed of niobium or tantalum having been treated by pickling and oxidation.
Description
1~5~ 3 This invention relates to the use of treated niobium or tantalum as a connector and such a connector and has particular reference to the treatment of niobium or tantalum to improve its resistance to a previously unknown crevice corrosion attack.
It has already been proposed to use niobium as a connector, particularly for use in a saline solution such as seawater. Such a connector is described in detail in British Patent No. 2 001 807, published on February 7, 1979 in the name of Marston Excelsior Limited. Niobium is chosen as a particularly suitable material for such a connector for a number of reasons. The purpose of the connector is to permit a dismantelable connection to be made in an electrical line feediny positive current to an underseas anode in an impressed current cathodic protection system.
The electrical connector proposed in Patent Specification No. 2 001 807 has a number of distinct - 1 - ' ;3 . ' . ~
~ .
~S~13 advantages over previous eLectrical connectors in that it is easily dismantlable and assemblable and by comparison to previous connectors is comparatively inexpensive. Niobium is chosen as a particularly suitable material for such an electrical connector as it is normally recognised that niobium can be connected and operated as an anode in a saline solution, such as seawater, without corroding at anodic voltages less than approximately lnO volts.
The anodic properties of niobium are well-known and it is well-known that niobium forms a resistant and insulating niobium oxide film at applLed voltages of up to 100 volts. Above that volta~e, known as the breakdown voltage, ~he film fails and the material corrodes rapidly. Before the present invention, however, it was considered that bulk niobium was self-passivating at voltages below the breakdown voltage. Unexpectedly, however, it was found that when connectors formed of niobium were tested they could, in certain conditions, corrode rapidly. Why this should happen was not to be found in any literature known to the applicants. An answer to the problem has now been found and basically the solution, which forms one feature of the present invention, is to pre-treat the niobium by pickling to remove contamination and surface oxlde films and subsequently to form an oxide film on the surface of the niobium.
As a result of investigations carried out by the applicants it has been found that such a pre-treatment is known per se but has only been proposed as a method of forming a smooth surface, 5~713 for example in the treatment of superconductor cavity resonators.
Thus, in British Paten-t Specification No 1 335 165 there is described the treatmen~ of the internal niobium surface of a superconducting cavity resonator by pickling in a mixture of nitric acid and hydrofluoric acid and subsequently anodising the resonator surface in an aqueous ammonia solution.
There is no indication, however, from this prior patent specification that the material so treated is particularly suitable for use as a connector in a saline solution or that such a material would be resistant to corrosion. It is apparent, therefore, that the inventors have discovered an unexpected property of niobium when treated in a manner known per se. The fact that the niobium is, when in use, connected as an anode and yet can suffer from corrosion, increases the novelty of the invention insofar as a pre-treatment comprising pickling and anodisation substantially prevents corrosion at a later date.
It has also been found, as 21 result of work carried out by the inventors, that pickliing alone is not sufficient, nor is anodisation alone sufficient.
Thus, it is necessary to have the combination of steps before the beneficial effects of the invention are to be found.
It is, of course, well-known to anodise niobium, as is described, for example, in British Patent Specification No 1 228 939 or US ]?atent Specification No 3 496 076, and it iis also known to pickle and subsequently anodise niobium or use as a superconducting cavity resonator as is described in , ~ :
British Patent Specification No 1 335 165 referred to above.
It appears that the particular problem associated with the use of niobium as a connector occurs when the niobium is located in a saline solution and is connected anodically. Thus, when niobium is inserted in a cold saline solution but is not connected as an anode it does not corrode.
However, when connected as an anode, in certain circumstances it has been found that corrosion can occur. To the best of the inventors' ~nowledge this fact was never known prior to the making of the present invention.
In U5 Patent Specification No 3 730 856 there is described a method of anodising titanium or niobium to remove surface ion contamination so as to improve ! the corrosion resistance of chemical plant where the metal surfaces are in contact with hydrogen. However, there is no reference to the particular advantages to be obtained from using pickled and anodised niobium as a connector in a saline environment.
It has also been proposed see, for example, British Patent Specification No 1 430 185, to reduce the susceptibility of titanium to crevice corrosion by abrading and pickling in hydrofluoric and nitric acid mixtures to remove ion surface contamination.
However, this specification does not point out the advantages of the present treatment of niobium.
In US Patent Specification No 3 876 136 niobium (ie columbium) is used in place of titanium where titanium is said to be susceptible to crevice - attack. The specification does not draw the conclusion that pickling and anodisation of the ~S~
niobium is necessary~ In other words, from this specification it will be concluded that niobium is itself resistant to crevice corrosion without the need for any treatment of it.
In US Paten~ Specification No 3 A69 975 it is stated that the problem of containing halide solutions is complicated by the complete unpredictability of susceptibility ~of materials) to crevice corrosion.
This reference is to be found in column 2, lines 1 to 3, of the specification. In lines 27 to 32 there is further reference to the complete unpredictability of materials to crevice corrosion.
Although crevice corrosion of materials is well-known for materials such as steel - see, for example, a paper published by W D France Jr in a symposium presented at the Seventy-Fourth Annual Meeting of the American Society for Testing and Materials, 27 3une to 2 July 1971, published as ASTM
Special Technical Publication 516, pages 164 to 196 -there was no indication that niobium was a materialwhich could suffer such a corrosion. Furthermore, in a publica~ion by the Centre Belge d'Etude de la Corrosion published in Brussels, June 1957, reference NZ.55 JVM.144, entitled "Electrochemical Resistance of Niobium" by J Van Muylder, N de Zoubor and M Pourbaix it is stated that the resistance of niobium to corrosion is that of a refractory metal, unattacked in air, oxygen and water, that it is not attacked by normal acids, such as hydrochloric, sulphuric and nitric acids or their mixtures, that aqua regia has no action and that the same is true of caustic alkali solutions. Because it is so inert to reactive chemicals it is necessary to use fused caustic alkalis 4~i3 or alkaline carbides or their complex solutions to attack it.
The paper goes on to say that hydrofluoric acid attacks niobium only slowly but the rate of attack can be increased if the niobium is contacted with platinum. Alternatively, the rate of attack can be increased by adding nitric acid to the hydro-fluoric acid. It is believed that the niobium forms complex fluorides or oxy-fluorides.
The paper concludes by saying that the known resistance of niobium to the action of chemical agents gives rise to the conclusion that the niobium oxide which forms on the metal constitutes an effective protective oxide. The paper ends by stating that in the absence of complexing substances the metal niobium is virtually non-corrodihle.
Thus, contrary to the prior art discussed above, it has been found that the treatment of niobium known per se can give unexpected increases in the resistance of niobium to crevice corrosion, particularly when anodically connected as an electrical connector in ~ saline solution.
According to the present invention, there is provided a method of preparing an electrical connector for use in an electrical line of a cathodic protection system said electrical line feeding positive current to an anode, the connector being formed of a metal selected from the group consisting of niobium and tantalum, the method comprising treating the connector before use by a two stage process:
(a) pickling to remove contamination and surface oxide films and (b) forming an oxide film on the surface of the connector by oxidising the surface of the connector.
In another aspect, the invention provides an elongate electrical connector incorporating at least a surface portion of niobium or tantalum having been pre-treated by pickling to remove contaminated surface oxide film and subsequently having had its surface oxidised to form an oxide film.
The invention also provides an electrical connector adapted to be immersed in sea water and anodically polarised, the connector being constructed of a metal selected from the group consisting of niobium and tantalum, the surface of the metal having been pickled to remove contamination and surface oxide films and having a fresh oxide surface film formed thereon by oxidation of the surface of the connector.
Thus, use is made of niobium or tantalum, which has been treated in a manner known per se by pickling to remove contamination and surface oxide films, and subsequently forming an oxide film on its surface, as a connector in a saline solution. The present invention also provides for the use of niobium in which the oxide is formed by anodisation in a manner known per se. The connector may be used when anodically polarised in the saline solution. The - 6a -~1~9L'7~3 saline solution may be an aqueous saline solution and the niobium may be polarised at a voltage in the range 30-100 volts. The present invention t--urther provides a niobium or tantaium member exposed, in use, to a saline solution and having been treated by pickling to remove contaminated surface oxide films and subsequently having formed on its suriace an oxide film.
The present invention further provides a cathodic protection system incorporating such a connector.
By way of example the treatmen~ of niobium and the advantages to be obtained thereby ~11 be described below.
A piece of extruded niobium was partially covered with a piece of plastics tape and was inserted in a hot saline solution and connected as an anode at 50 volts. It was found that after a short period of time white niobium oxide corrosion products were to be found adjacent the piece of plastics tape. Two similar pieces of niobium were then treated in the following manner. A first piece was treated by a method not in accordance with the present invention.
It was pickled in a solution of hydrofluoric acid and nitric acid and then washed in water. The material was then again wrapped in tape and connected as an anode at 44 volts in a saline solution containing 250g/1 Na~l at a pH of 2. Again, corrosion products were found on the surface.
The second piece of niobium was then pickled in a hydrofluoric acid and nitric acid mixture to remove 40 microns of niobium, washed in water and ~L~5~ 3 su~seqently anodised in an ammonium sulpha-te solution at 40 volts to form an anodic film on the surface of the niobiu~.
This sample was then partially wrapped with a plastics tape and treated in the manner of the first sample mentioned above. This piece of niobium, which had been treated in accordance with the present inventionr was found to suffer no attack whats~ever.
By way of comparison third and fourth samples o extruded niobium were merely anodised in aqueous NaCl containing 20g/1 and 220g/1 NaCl at 40 volts and covered with plastics tape. These samples were then tested in accordance with the first-mentioned sample.
This sample, again not in accordance wiih the present invention, was also ound to corrode.
It can thus be seen that the combination of pickling and forming the oxide layer - which could be formed by air oxidation of the,niobium - leads to unexpected improvements in the corrosion resistance of niobium when used as a connec-tor, particularly as an electrical connector in a saline solution, such as seawater. It will be realised that hot water was used to accelerate the effect of corrosion. Tantalum behaves in a similar manner to niobium, havin~ a similar normal breakdown potential.
The connectors were particularly useful for cathodic protection installations.
It has already been proposed to use niobium as a connector, particularly for use in a saline solution such as seawater. Such a connector is described in detail in British Patent No. 2 001 807, published on February 7, 1979 in the name of Marston Excelsior Limited. Niobium is chosen as a particularly suitable material for such a connector for a number of reasons. The purpose of the connector is to permit a dismantelable connection to be made in an electrical line feediny positive current to an underseas anode in an impressed current cathodic protection system.
The electrical connector proposed in Patent Specification No. 2 001 807 has a number of distinct - 1 - ' ;3 . ' . ~
~ .
~S~13 advantages over previous eLectrical connectors in that it is easily dismantlable and assemblable and by comparison to previous connectors is comparatively inexpensive. Niobium is chosen as a particularly suitable material for such an electrical connector as it is normally recognised that niobium can be connected and operated as an anode in a saline solution, such as seawater, without corroding at anodic voltages less than approximately lnO volts.
The anodic properties of niobium are well-known and it is well-known that niobium forms a resistant and insulating niobium oxide film at applLed voltages of up to 100 volts. Above that volta~e, known as the breakdown voltage, ~he film fails and the material corrodes rapidly. Before the present invention, however, it was considered that bulk niobium was self-passivating at voltages below the breakdown voltage. Unexpectedly, however, it was found that when connectors formed of niobium were tested they could, in certain conditions, corrode rapidly. Why this should happen was not to be found in any literature known to the applicants. An answer to the problem has now been found and basically the solution, which forms one feature of the present invention, is to pre-treat the niobium by pickling to remove contamination and surface oxlde films and subsequently to form an oxide film on the surface of the niobium.
As a result of investigations carried out by the applicants it has been found that such a pre-treatment is known per se but has only been proposed as a method of forming a smooth surface, 5~713 for example in the treatment of superconductor cavity resonators.
Thus, in British Paten-t Specification No 1 335 165 there is described the treatmen~ of the internal niobium surface of a superconducting cavity resonator by pickling in a mixture of nitric acid and hydrofluoric acid and subsequently anodising the resonator surface in an aqueous ammonia solution.
There is no indication, however, from this prior patent specification that the material so treated is particularly suitable for use as a connector in a saline solution or that such a material would be resistant to corrosion. It is apparent, therefore, that the inventors have discovered an unexpected property of niobium when treated in a manner known per se. The fact that the niobium is, when in use, connected as an anode and yet can suffer from corrosion, increases the novelty of the invention insofar as a pre-treatment comprising pickling and anodisation substantially prevents corrosion at a later date.
It has also been found, as 21 result of work carried out by the inventors, that pickliing alone is not sufficient, nor is anodisation alone sufficient.
Thus, it is necessary to have the combination of steps before the beneficial effects of the invention are to be found.
It is, of course, well-known to anodise niobium, as is described, for example, in British Patent Specification No 1 228 939 or US ]?atent Specification No 3 496 076, and it iis also known to pickle and subsequently anodise niobium or use as a superconducting cavity resonator as is described in , ~ :
British Patent Specification No 1 335 165 referred to above.
It appears that the particular problem associated with the use of niobium as a connector occurs when the niobium is located in a saline solution and is connected anodically. Thus, when niobium is inserted in a cold saline solution but is not connected as an anode it does not corrode.
However, when connected as an anode, in certain circumstances it has been found that corrosion can occur. To the best of the inventors' ~nowledge this fact was never known prior to the making of the present invention.
In U5 Patent Specification No 3 730 856 there is described a method of anodising titanium or niobium to remove surface ion contamination so as to improve ! the corrosion resistance of chemical plant where the metal surfaces are in contact with hydrogen. However, there is no reference to the particular advantages to be obtained from using pickled and anodised niobium as a connector in a saline environment.
It has also been proposed see, for example, British Patent Specification No 1 430 185, to reduce the susceptibility of titanium to crevice corrosion by abrading and pickling in hydrofluoric and nitric acid mixtures to remove ion surface contamination.
However, this specification does not point out the advantages of the present treatment of niobium.
In US Patent Specification No 3 876 136 niobium (ie columbium) is used in place of titanium where titanium is said to be susceptible to crevice - attack. The specification does not draw the conclusion that pickling and anodisation of the ~S~
niobium is necessary~ In other words, from this specification it will be concluded that niobium is itself resistant to crevice corrosion without the need for any treatment of it.
In US Paten~ Specification No 3 A69 975 it is stated that the problem of containing halide solutions is complicated by the complete unpredictability of susceptibility ~of materials) to crevice corrosion.
This reference is to be found in column 2, lines 1 to 3, of the specification. In lines 27 to 32 there is further reference to the complete unpredictability of materials to crevice corrosion.
Although crevice corrosion of materials is well-known for materials such as steel - see, for example, a paper published by W D France Jr in a symposium presented at the Seventy-Fourth Annual Meeting of the American Society for Testing and Materials, 27 3une to 2 July 1971, published as ASTM
Special Technical Publication 516, pages 164 to 196 -there was no indication that niobium was a materialwhich could suffer such a corrosion. Furthermore, in a publica~ion by the Centre Belge d'Etude de la Corrosion published in Brussels, June 1957, reference NZ.55 JVM.144, entitled "Electrochemical Resistance of Niobium" by J Van Muylder, N de Zoubor and M Pourbaix it is stated that the resistance of niobium to corrosion is that of a refractory metal, unattacked in air, oxygen and water, that it is not attacked by normal acids, such as hydrochloric, sulphuric and nitric acids or their mixtures, that aqua regia has no action and that the same is true of caustic alkali solutions. Because it is so inert to reactive chemicals it is necessary to use fused caustic alkalis 4~i3 or alkaline carbides or their complex solutions to attack it.
The paper goes on to say that hydrofluoric acid attacks niobium only slowly but the rate of attack can be increased if the niobium is contacted with platinum. Alternatively, the rate of attack can be increased by adding nitric acid to the hydro-fluoric acid. It is believed that the niobium forms complex fluorides or oxy-fluorides.
The paper concludes by saying that the known resistance of niobium to the action of chemical agents gives rise to the conclusion that the niobium oxide which forms on the metal constitutes an effective protective oxide. The paper ends by stating that in the absence of complexing substances the metal niobium is virtually non-corrodihle.
Thus, contrary to the prior art discussed above, it has been found that the treatment of niobium known per se can give unexpected increases in the resistance of niobium to crevice corrosion, particularly when anodically connected as an electrical connector in ~ saline solution.
According to the present invention, there is provided a method of preparing an electrical connector for use in an electrical line of a cathodic protection system said electrical line feeding positive current to an anode, the connector being formed of a metal selected from the group consisting of niobium and tantalum, the method comprising treating the connector before use by a two stage process:
(a) pickling to remove contamination and surface oxide films and (b) forming an oxide film on the surface of the connector by oxidising the surface of the connector.
In another aspect, the invention provides an elongate electrical connector incorporating at least a surface portion of niobium or tantalum having been pre-treated by pickling to remove contaminated surface oxide film and subsequently having had its surface oxidised to form an oxide film.
The invention also provides an electrical connector adapted to be immersed in sea water and anodically polarised, the connector being constructed of a metal selected from the group consisting of niobium and tantalum, the surface of the metal having been pickled to remove contamination and surface oxide films and having a fresh oxide surface film formed thereon by oxidation of the surface of the connector.
Thus, use is made of niobium or tantalum, which has been treated in a manner known per se by pickling to remove contamination and surface oxide films, and subsequently forming an oxide film on its surface, as a connector in a saline solution. The present invention also provides for the use of niobium in which the oxide is formed by anodisation in a manner known per se. The connector may be used when anodically polarised in the saline solution. The - 6a -~1~9L'7~3 saline solution may be an aqueous saline solution and the niobium may be polarised at a voltage in the range 30-100 volts. The present invention t--urther provides a niobium or tantaium member exposed, in use, to a saline solution and having been treated by pickling to remove contaminated surface oxide films and subsequently having formed on its suriace an oxide film.
The present invention further provides a cathodic protection system incorporating such a connector.
By way of example the treatmen~ of niobium and the advantages to be obtained thereby ~11 be described below.
A piece of extruded niobium was partially covered with a piece of plastics tape and was inserted in a hot saline solution and connected as an anode at 50 volts. It was found that after a short period of time white niobium oxide corrosion products were to be found adjacent the piece of plastics tape. Two similar pieces of niobium were then treated in the following manner. A first piece was treated by a method not in accordance with the present invention.
It was pickled in a solution of hydrofluoric acid and nitric acid and then washed in water. The material was then again wrapped in tape and connected as an anode at 44 volts in a saline solution containing 250g/1 Na~l at a pH of 2. Again, corrosion products were found on the surface.
The second piece of niobium was then pickled in a hydrofluoric acid and nitric acid mixture to remove 40 microns of niobium, washed in water and ~L~5~ 3 su~seqently anodised in an ammonium sulpha-te solution at 40 volts to form an anodic film on the surface of the niobiu~.
This sample was then partially wrapped with a plastics tape and treated in the manner of the first sample mentioned above. This piece of niobium, which had been treated in accordance with the present inventionr was found to suffer no attack whats~ever.
By way of comparison third and fourth samples o extruded niobium were merely anodised in aqueous NaCl containing 20g/1 and 220g/1 NaCl at 40 volts and covered with plastics tape. These samples were then tested in accordance with the first-mentioned sample.
This sample, again not in accordance wiih the present invention, was also ound to corrode.
It can thus be seen that the combination of pickling and forming the oxide layer - which could be formed by air oxidation of the,niobium - leads to unexpected improvements in the corrosion resistance of niobium when used as a connec-tor, particularly as an electrical connector in a saline solution, such as seawater. It will be realised that hot water was used to accelerate the effect of corrosion. Tantalum behaves in a similar manner to niobium, havin~ a similar normal breakdown potential.
The connectors were particularly useful for cathodic protection installations.
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of preparing an electrical connector for use in an electrical line of a cathodic protection system said electrical line feeding positive current to an anode, the connector being formed of a metal selected from the group consisting of niobium and tantalum, the method comprising treating the connector before use by a two stage process:
(a) pickling to remove contamination and surface oxide films and (b) forming an oxide film on the surface of the connec-tor by oxidising the surface of the connector.
(a) pickling to remove contamination and surface oxide films and (b) forming an oxide film on the surface of the connec-tor by oxidising the surface of the connector.
2. The method as claimed in claim 1 in which the connector is formed of niobium and the oxide is formed by anodisation.
3. An elongate electrical connector incorporating at least a surface portion of niobium or tantalum having been pre-treated by pickling to remove contaminated surface oxide film and subse-quently having had its surface oxidised to form an oxide film.
4. An electrical connector adapted to be immersed in sea water and anodically polarised, the connector being constructed of a metal selected from the group consisting of niobium and tantalum, the surface of the metal having been pickled to remove contamina-tion and surface oxide films and having a fresh oxide surface film formed thereon by oxidation of the surface of the connector.
5. The electrical connector as claimed in claim 4 integral with a portion of niobium or tantalum having on its surface a platinum group metal or platinum group metal oxide.
6. An elongate connector as claimed in claim 3 wherein the metal of the surface of the connector is niobium and the connector has one end adapted to be connectable to an electrical cable and is integral at the other end with a portion of niobium having its surface coated with a platinum group metal or platinum group metal oxide.
7. An electrical connector according to claim 3 wherein the connector is adapted for interconnecting an electrical cable and a cathodic protection anode.
8. An electrical connector as claimed in claim 7, intercon-nected to a said cathodic protection anode having a platinised niobium surface.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB40708/78 | 1978-10-16 | ||
| GB7840708 | 1978-10-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1154713A true CA1154713A (en) | 1983-10-04 |
Family
ID=10500372
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000337562A Expired CA1154713A (en) | 1978-10-16 | 1979-10-15 | Electrical connector of tantalum or niobium for cathodic protection system |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0010382B1 (en) |
| JP (1) | JPS5554579A (en) |
| AU (1) | AU5164379A (en) |
| CA (1) | CA1154713A (en) |
| DE (1) | DE2965863D1 (en) |
| NO (1) | NO793212L (en) |
| NZ (1) | NZ191803A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11069995B1 (en) | 2020-02-07 | 2021-07-20 | Northrop Grumman Systems Corporation | Single self-insulating contact for wet electrical connector |
| US10985495B1 (en) * | 2020-02-24 | 2021-04-20 | Northrop Grumman Systems Corporation | High voltage connector with wet contacts |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3378471A (en) * | 1965-06-17 | 1968-04-16 | Gen Electric | Anodized tantalum and niobium and method of forming an oxide coating thereon |
| US3502552A (en) * | 1965-11-30 | 1970-03-24 | Matsushita Electric Ind Co Ltd | Method for anodic oxidation of titanium and its alloys |
| DE2106628C3 (en) * | 1971-02-12 | 1974-02-14 | Siemens Ag, 1000 Berlin U. 8000 Muenchen | Process for the surface treatment of superconducting niobium cavity resonators |
| US3730856A (en) * | 1971-02-26 | 1973-05-01 | Ici Ltd | Electrolytic preparation of valve group metal equipment for use in chemical plants |
| DE2239425C3 (en) * | 1972-08-10 | 1978-04-20 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Process for the electrolytic treatment of niobium surfaces for alternating current applications |
| ZA783792B (en) * | 1977-07-26 | 1979-07-25 | Marston Excelsior Ltd | Electrical connector |
-
1979
- 1979-10-04 EP EP79302109A patent/EP0010382B1/en not_active Expired
- 1979-10-04 DE DE7979302109T patent/DE2965863D1/en not_active Expired
- 1979-10-05 NO NO793212A patent/NO793212L/en unknown
- 1979-10-09 NZ NZ191803A patent/NZ191803A/en unknown
- 1979-10-10 AU AU51643/79A patent/AU5164379A/en not_active Abandoned
- 1979-10-15 CA CA000337562A patent/CA1154713A/en not_active Expired
- 1979-10-15 JP JP13278179A patent/JPS5554579A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| NZ191803A (en) | 1983-02-15 |
| EP0010382B1 (en) | 1983-07-13 |
| NO793212L (en) | 1980-04-17 |
| EP0010382A2 (en) | 1980-04-30 |
| AU5164379A (en) | 1980-04-24 |
| DE2965863D1 (en) | 1983-08-18 |
| EP0010382A3 (en) | 1980-05-14 |
| JPS5554579A (en) | 1980-04-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0085701B1 (en) | Copper-containing articles with a corrosion inhibitor coating and methods of producing the coating | |
| DE2744254C3 (en) | A method of pretreating a zirconium or zirconium alloy article prior to electrolessly depositing a metal film thereon and using it | |
| CA1154713A (en) | Electrical connector of tantalum or niobium for cathodic protection system | |
| US3625908A (en) | Composition for cleaning photographic equipment | |
| RU94014613A (en) | Corrosion protection system | |
| DE2447670B2 (en) | PROCESS FOR THE SELECTIVE ETCHING OF A SILICON OXIDE LAYER ON A SUBSTRATE | |
| Sayed et al. | Inhibitive effects of benzotriazole on the stress corrosion cracking of α-brass in nitrite solution | |
| US4861374A (en) | Non-abrasive polish or cleaning composition and process for its preparation | |
| US5635084A (en) | Method for creating a corrosion-resistant surface on an aluminum-copper alloy | |
| DE1421994A1 (en) | Process, device and means for cleaning metal surfaces | |
| Notoya et al. | Benzotriazole and tolyltriazole as corrosion inhibitors for copper and brasses | |
| Davies et al. | Passivation and pitting characteristics of zinc | |
| Trabanelli et al. | Behaviour of nickel and its alloys inacidic media | |
| Evans | LXVI.—The passivity of metals. Part IV. The influence of acids in passivity and corrosion | |
| Abdel Hady et al. | Anodic behaviour of titanium in concentrated sulphuric acid solutions. Influence of some oxidizing inhibitors | |
| US4145267A (en) | Nonplating cathode and method for producing same | |
| LEIDHEISER JR et al. | Strain Electrometry Studies of Aluminum | |
| US3900348A (en) | Method for protecting copper surfaces against corrosion | |
| Britton et al. | The corrosion of tin by aqueous solutions of ammonia | |
| Ashworth et al. | The Effect of Ion Implantation on the Corrosion Behaviour of Fe | |
| Bakulin | Electrochemical Protection of Aluminum Alloys in Sea Water.(Translation) | |
| US3011957A (en) | Method for protecting metals against corrosion | |
| Schlain | Certain Aspects of the Galvanic Corrosion Behavior of Titanium | |
| US3660294A (en) | Method of cleaning glass | |
| El Shayeb et al. | Electrochemical behaviour of Al, Cu, and Al–Cu alloys in NaOH and HCl solutions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |