EP0010382B1 - Verwendung von behandeltem Niob oder Tantal für einen elektrischen Steckverbinder, ein solcher Steckverbinder und ein kathodisches Schutzsystem, das einen solchen Stecker verwendet - Google Patents

Verwendung von behandeltem Niob oder Tantal für einen elektrischen Steckverbinder, ein solcher Steckverbinder und ein kathodisches Schutzsystem, das einen solchen Stecker verwendet Download PDF

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Publication number
EP0010382B1
EP0010382B1 EP79302109A EP79302109A EP0010382B1 EP 0010382 B1 EP0010382 B1 EP 0010382B1 EP 79302109 A EP79302109 A EP 79302109A EP 79302109 A EP79302109 A EP 79302109A EP 0010382 B1 EP0010382 B1 EP 0010382B1
Authority
EP
European Patent Office
Prior art keywords
niobium
connector
tantalum
treated
saline solution
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
Application number
EP79302109A
Other languages
English (en)
French (fr)
Other versions
EP0010382A2 (de
EP0010382A3 (en
Inventor
Michael Anthony Warne
Peter Charles Steele Hayfield
William Raymond Bennett
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Marston Ltd
Marston Palmer Ltd
Original Assignee
Denso Marston Ltd
Marston Palmer Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Denso Marston Ltd, Marston Palmer Ltd filed Critical Denso Marston Ltd
Publication of EP0010382A2 publication Critical patent/EP0010382A2/de
Publication of EP0010382A3 publication Critical patent/EP0010382A3/xx
Application granted granted Critical
Publication of EP0010382B1 publication Critical patent/EP0010382B1/de
Expired legal-status Critical Current

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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

Definitions

  • 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.
  • 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 dismantlable connection to be made in an electrical line feeding positive current to an underseas anode in an impressed current cathodic protection system.
  • 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 100 volts.
  • a saline solution such as seawater
  • the anodic properties of niobium are well-known and it is well-known that niobium forms a resistant and insulating niobium oxide film at applied voltages of up to 100 volts.
  • niobium when in use, connected as an anode and yet can suffer from corrosion if not treated in the manner according to this invention, increases the novelty of the invention insofar as a pretreatment comprising pickling and anodisation substantially prevents corrosion at a later date.
  • niobium i.e. columbium
  • niobium 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 niobium is necessary.
  • niobium is itself resistant to crevice corrosion without the need for any treatment of it.
  • 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 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 touched with platinum. Alternatively, the rate of attack can be increased by adding nitric acid to the hydrofluoric 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-corrodable.
  • niobium or tantalum as a connector in a saline solution, anodically polarised at a voltage between 10 and 100 volts and having been pre-treated before use as a connector in a manner known per se by pickling in a hydrofluoric acid containing solution to remove contamination and surface oxide films and subsequently anodising it in a suitable solution to form an oxide film on its surface.
  • the pickling solution contains hydrofluoric acid and nitric acid.
  • the present invention further provides an electrical connector including a niobium or tantalum member exposed, in use, to a saline solution, the niobium or tantalum member being anodically polarised at a voltage between 10 and 100 volts and having been treated in the manner set out above.
  • the present invention also provides a cathodic protection system incorporating an electrical connector of the type set out above.
  • 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 250 g/I NaCI 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 subsequently anodised in an ammonium sulphate solution at 40 volts to form an anodic film on the surface of the niobium.
  • third and fourth samples of extruded niobium were merely anodised in aqueous NaCi containing 20 g/I and 220 g/I NaCI 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 with the present invention, was also found to corrode.
  • the connectors were particularly useful for cathodic protection installations.

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)

Claims (4)

1. Die Verwendung von Niob oder Tantal für ein Verbindungsglied in einer Salzlösung, welches bei einer Spannung zwischen 10 und 100 V anodisch polarisiert und vor der Verwendung als Verbindungsglied in einer an sich bekannten Weise vorbehandelt worden ist durch Beizen in einer Fluorwasserstoffsäure enthaltenden Lösung zur Entfernung von Verunreinigungen und Oberflächenoxidfilmen und durch anschließendes Anodisieren in einer geeigneten Lösung zur Bildung eines Oxidfilms auf seiner Oberfläche.
2. Die Verwendung von Niob oder Tantal als Verbindungsglied in einer Salzlösung nach Anspruch 1, wobei die Beizlösung Fluorwasserstoffsäure und Salpetersäure enthält.
3. Elektrisches Verbindungsglied mit einem Niob- oder Tantalteil, das beim Gebrauch einer Salzlösung ausgesetzt wird, wobei das Niob-oder Tantalteil bei einer Spannung zwischen 10 und 100 V anodisch polarisiert und in der in Anspruch 1 oder 2 beschriebenen Weise behandelt worden ist.
4. Kathodisches Schutzsystem, welches ein elektrisches Verbindungsglied nach Anspruch 1, 2 oder 3 enthält.
EP79302109A 1978-10-16 1979-10-04 Verwendung von behandeltem Niob oder Tantal für einen elektrischen Steckverbinder, ein solcher Steckverbinder und ein kathodisches Schutzsystem, das einen solchen Stecker verwendet Expired EP0010382B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB7840708 1978-10-16
GB4070878 1978-10-16

Publications (3)

Publication Number Publication Date
EP0010382A2 EP0010382A2 (de) 1980-04-30
EP0010382A3 EP0010382A3 (en) 1980-05-14
EP0010382B1 true EP0010382B1 (de) 1983-07-13

Family

ID=10500372

Family Applications (1)

Application Number Title Priority Date Filing Date
EP79302109A Expired EP0010382B1 (de) 1978-10-16 1979-10-04 Verwendung von behandeltem Niob oder Tantal für einen elektrischen Steckverbinder, ein solcher Steckverbinder und ein kathodisches Schutzsystem, das einen solchen Stecker verwendet

Country Status (7)

Country Link
EP (1) EP0010382B1 (de)
JP (1) JPS5554579A (de)
AU (1) AU5164379A (de)
CA (1) CA1154713A (de)
DE (1) DE2965863D1 (de)
NO (1) NO793212L (de)
NZ (1) NZ191803A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
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

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10985495B1 (en) * 2020-02-24 2021-04-20 Northrop Grumman Systems Corporation High voltage connector with wet contacts

Family Cites Families (6)

* Cited by examiner, † Cited by third party
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 (de) * 1971-02-12 1974-02-14 Siemens Ag, 1000 Berlin U. 8000 Muenchen Verfahren zur Oberflächenbehandlung von supraleitenden Niob-Hohlraumresonatoren
US3730856A (en) * 1971-02-26 1973-05-01 Ici Ltd Electrolytic preparation of valve group metal equipment for use in chemical plants
DE2239425C3 (de) * 1972-08-10 1978-04-20 Siemens Ag, 1000 Berlin Und 8000 Muenchen Verfahren zur elektrolytischen Behandlung von Nioboberflächen für Wechselstromanwendungen
ZA783792B (en) * 1977-07-26 1979-07-25 Marston Excelsior Ltd Electrical connector

Cited By (1)

* Cited by examiner, † Cited by third party
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

Also Published As

Publication number Publication date
NZ191803A (en) 1983-02-15
CA1154713A (en) 1983-10-04
NO793212L (no) 1980-04-17
EP0010382A2 (de) 1980-04-30
AU5164379A (en) 1980-04-24
DE2965863D1 (en) 1983-08-18
EP0010382A3 (en) 1980-05-14
JPS5554579A (en) 1980-04-21

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