US3887443A
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Method for forming a carbide layer of an element selected from the group consisting of V, Nb, Ta and mixtures thereof on the surface of an iron, ferrous alloy or cemented carbide article
Assignee: Toyota Central R&D Labs Inc
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Filing: 1973-04-27
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Granted: 1975-06-03
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Expires: 1993-04-27
Abstract
Abstract A method for forming a carbide layer of an element selected from the group consisting of V, Nb, Ta on the surface of an iron, ferrous alloy or cemented carbide article in a treating molten bath, comprising preparing the treating molten bath composed of boron oxide and an element selected from the group consisting of V, Nb, Ta immersing the article in the treating molten bath and applying an electric current to the treating molten bath through said article being used as the cathode, thereby forming a very hard carbide layer of said element on the surface of said article. The method of this invention can form quickly a uniform and dense carbide layer on the surface of the article and can be carried out in the open air.
Inventors
- 👤 Noboru Komatsu
- 👤 Tohru Arai
- 👤 Yoshihiko Sugimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:52
CPC Classifications
C; C25; C25D; C25D9/00; C25D9/04; C25D9/08
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
146 words
A method for forming a carbide layer of an element selected from the group consisting of V, Nb, Ta and mixtures thereof on the surface of an iron, ferrous alloy or cemented carbide article, said article containing at least 0.05 percent by weight of iron, comprising the steps of preparing a treating molten bath composed of molten boron oxide and a substance containing an element selected from the group consisting of V, Nb, Ta and mixtures thereof in a vessel, immersing said article into the treating molten bath, applying an electric current to the treating molten bath, through said article being used as the cathode for depositing the element on the surface of the article and for forming the carbide layer of said element, with the carbon contained within said article, on the surface of said article, and removing the article from the treating molten bath.
Claim 2
Independent Claim
146 words
A method for forming a carbide layer of an element selected from the group consisting of V, Nb, Ta and mixtures thereof on the surface of an iron, ferrous alloy or cemented carbide article, said article containing at least 0.05 percent by weight of iron, comprising the steps of preparing a treating molten bath composed of molten boron oxide and a substance containing an element selected from the group consisting of V, Nb, Ta and mixtures thereof in a vessel, immersing said article into the treating molten bath, applying an electric current to the treating molten bath, through said article being used as the cathode for depositing the element on the surface of the article and for forming the carbide layer of said element, with the carbon contained within said article, on the surface of said article, and removing the article from the treating molten bath.
Claim 3
Independent Claim
119 words
A METHOD FOR FORMING A CARBIDE LAYER OF AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF V,NB,TA AND MIXTURES THEREOF ON THE SURFACE OF AN IRON, FERROUS ALLOY OR CEMENTED CARBIDE ARTICLE SAID ARTICLE CONTAINING AT LEAST 0.05 PERCENT BY WEIGHT OF IRON, COMPRISING THE STEPS OF PREPARING A TREATING MOLTEN BATH COMPOSED OF MOLTEN BORON OXIDE AND A SUBSTANCE CONTAINING AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF V,NB,TA MIXTURES THEREOF IN A VESSEL, IMMERSING SAID ARTICLE INTO THE TREATING MOLTEN BATH, APPLYING AN ELECTRIC CURRENT TO THE TREATING MOLTEN BATH, THROUGH SAID ARTICLE BEING USED AS THE CATHODE FOR DEPOSITING THE ELEMENT ON THE SURFACE OF THE ARTICLE, AND FOR FORMING THE CARBIDE LAYER OF SAID ELE-
Claim 4
Independent Claim
119 words
A METHOD FOR FORMING A CARBIDE LAYER OF AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF V,NB,TA AND MIXTURES THEREOF ON THE SURFACE OF AN IRON, FERROUS ALLOY OR CEMENTED CARBIDE ARTICLE SAID ARTICLE CONTAINING AT LEAST 0.05 PERCENT BY WEIGHT OF IRON, COMPRISING THE STEPS OF PREPARING A TREATING MOLTEN BATH COMPOSED OF MOLTEN BORON OXIDE AND A SUBSTANCE CONTAINING AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF V,NB,TA MIXTURES THEREOF IN A VESSEL, IMMERSING SAID ARTICLE INTO THE TREATING MOLTEN BATH, APPLYING AN ELECTRIC CURRENT TO THE TREATING MOLTEN BATH, THROUGH SAID ARTICLE BEING USED AS THE CATHODE FOR DEPOSITING THE ELEMENT ON THE SURFACE OF THE ARTICLE, AND FOR FORMING THE CARBIDE LAYER OF SAID ELE-
Claim 5
Dependent Claim
21 words
A method according to claim 1, wherein said boron oxide is selected from the group consisting of boric acid and borate.
Claim 6
Dependent Claim
21 words
A method according to claim 2, wherein said borate is selected from the group consisting of sodium borate and potassium borate.
Claim 7
Dependent Claim
33 words
A method according to claim 1, wherein said substance is a metallic powder containing said element and the current density of the cathode is selected within the range from 0.01 to 5 A/cm2.
Claim 8
Dependent Claim
26 words
A method according to claim 4, wherein said metallic powder is of the element selected from the group consisting of V, Nb, Ta and mixtures thereof.
Claim 9
Dependent Claim
29 words
A methoD according to claim 4, wherein said metallic powder is of an alloy containing the element selected from the group consisting of V, Nb, Ta and mixtures thereof.
Claim 10
Dependent Claim
13 words
A method according to claim 6, wherein said alloy is a ferrous. alloy.
Claim 11
Dependent Claim
44 words
A method according to claim 1, wherein said substance is an oxide of the element selected from the group consisting of V, Nb, Ta and mixtures thereof and the current density of the cathode is selected within the range from 0.1 to 15 A/cm2.
Claim 12
Dependent Claim
44 words
A method according to claim 1, wherein said substance is a chloride of the element selected from the group consisting of V, Nb, Ta and mixtures thereof and the current density of the cathode is selected within the range from 0.01 to 3 A/cm2.
Claim 13
Dependent Claim
77 words
A method according to claim 1, wherein the step of preparing the treating molten bath comprises heating a boron oxide in the vessel, dipping a metallic block containing the element selected from the group consisting of V, Nb, Ta and mixtures thereof and anodically dissolving said metallic block into the molten boron oxide, the current density of the cathode, in the step of applying an elecric current, is selected within a range from 0.01 to 5 A/cm2.
Claim 14
Independent Claim
157 words
A method for forming a carbide layer of an element selected from the group consisting of V, Nb, Ta and mixtures thereof on the surface of an iron or ferrous alloy article, said article containing at least 0.05 percent by weight of iron, comprising the steps of preparing a treating molten bath composed of molten boron oxide and a substance containing an element selected from the group consisting of V, Nb, Ta and mixtures thereof in a vessel, immersing said article into the treating molten bath, applying an electric current of a cathodic current density within the range from 0.01 to 5 A/cm2 to the treating molten bath through said article being used as the cathode for depositing the element on the surface of the article and for forming the carbide layer of said element, with the carbon contained within said article, on the surface of said article and removing the article from the treating molten bath.
Claim 15
Independent Claim
157 words
A method for forming a carbide layer of an element selected from the group consisting of V, Nb, Ta and mixtures thereof on the surface of an iron or ferrous alloy article, said article containing at least 0.05 percent by weight of iron, comprising the steps of preparing a treating molten bath composed of molten boron oxide and a substance containing an element selected from the group consisting of V, Nb, Ta and mixtures thereof in a vessel, immersing said article into the treating molten bath, applying an electric current of a cathodic current density within the range from 0.01 to 5 A/cm2 to the treating molten bath through said article being used as the cathode for depositing the element on the surface of the article and for forming the carbide layer of said element, with the carbon contained within said article, on the surface of said article and removing the article from the treating molten bath.
Claim 16
Independent Claim
157 words
A method for forming a carbide layer of an element selected from the group consisting of V, Nb, Ta and mixtures thereof on the surface of a cemented carbide article, said article containing at least 0.05 percent by weight of carbon, comprising the steps of preparing a treating molten bath composed of molten boron oxide and a substance containing an element selected from the group consisting of V, Nb, Ta and mixtures thereof in a vessel, immersing the cemented carbide article into the treating molten bath, applying an electric current of a cathodic current density within the range from 0.01 to 15 A/cm2 to the treating molten bath through said article being used as the cathode for depositing the element on the surface of the article and for forming the carbide layer of said element, with the carbon contained within said article, on the surface of said article and removing the article from the treating molten bath.
Claim 17
Independent Claim
157 words
A method for forming a carbide layer of an element selected from the group consisting of V, Nb, Ta and mixtures thereof on the surface of a cemented carbide article, said article containing at least 0.05 percent by weight of carbon, comprising the steps of preparing a treating molten bath composed of molten boron oxide and a substance containing an element selected from the group consisting of V, Nb, Ta and mixtures thereof in a vessel, immersing the cemented carbide article into the treating molten bath, applying an electric current of a cathodic current density within the range from 0.01 to 15 A/cm2 to the treating molten bath through said article being used as the cathode for depositing the element on the surface of the article and for forming the carbide layer of said element, with the carbon contained within said article, on the surface of said article and removing the article from the treating molten bath.
Claim 18
Dependent Claim
33 words
A method according to claim 1, wherein said treating molten bath is composed to molten boron oxide and 1 to 20 percent by weight of said substance dissolved in said molten boron oxide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |