US3930060A
Expired / Lapsed
US
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Method for forming a carbide layer of a V-a group element of the periodic table 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: 1975-12-30
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Expires: 1993-04-27
Abstract
Abstract A method for forming a carbide layer of a V-a group element of the periodic table on the surface of an iron, ferrous alloy or cemented carbide article in a treating molten bath, comprising heating a boric acid or borate up to its molten state to form a molten bath, dipping a metal containing a V-a group element into the molten bath, applying an electric current to the molten bath through said metal, which works as its anode, for anodically dissolving said metal into the molten bath to prepare the treating molten bath, and immersing the article in the treating molten bath, thereby forming a very hard carbide layer of said Va group element on the surface of said article. The method of this invention can form a very smooth carbide layer on the surface of the article.
Inventors
- 👤 Noboru Komatsu
- 👤 Tohru Arai
- 👤 Yoshihiko Sugimoto
- 👤 Masayoshi Mizutani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:29
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/18; C23C10/20; C23C10/24; C23C30/00; C23C30/005
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
189 words
IN A METHOD FOR FORMING A CARBIDE LAYER ON AN IRON, FERROUS ALLOY, OR CEMENTED CARRBICE ARTICLE, SAID ARTICLES CONTAINING AT LEAST 0.05% BY WEIGHT OF CARBON, WHICH COMPRISES PREPARING A MOLTEN TREATING BATH CONSISTING ESSENTIALLY OF BORIC ACID OR A BORATE AND A METALLIC ELEMENT DISSOLVED THEREIN, SAID METALLIC ELEMENT BEING SELECTED FROM THE GROUP CONSISTNG OF VANADIUM, NIOBIUM AND TANTALUM; IMMERSING SAID ARTICLE INTO SAID MOLTEN TREATING BATH; MAINTAINING SAID ARTICLE IN SAID MOLTEN TREATING BATH TO FORM A CARBIDE LAYER OF SAID METALLIC ELEMENT ON THE SURFACE OF SAID ARTICLE, AND REMOVING SAID ARTICLE FROM THE MOLTEN TREATING BATH; THE IMPROVEMENT WHEREIN SAID MOLTEN TREATING BATH IS PREPARED BY THE METHOD WHICH COMPRISES HEATING A BORIC ACID OR A BORATE TO ITS MOLTEN STATE TO FORM A MOLTEN BATH; DIPPING A METAL BLOCK CONTAINING AT LEAST ONE ELEMENT SELECTED FROM THE GROUP CONSISTING OF VANADIUM, NIOBIUM AND TANTALUM, AND APPLYING AN ELECTRIC CURRENT TO THE MOLTEN BATH THROUGH SAID METAL BLOCK AS THE ANODE AND AN ELECTRIC CONDUCTIVE MATERIAL, WHICH IS IN CONTACT WITH THE MOLTEN BATH AS THE CATHODE, TO ANODICALLY DISSOLVE SAID METAL BLOCK.
Claim 2
Dependent Claim
189 words
IN A METHOD FOR FORMING A CARBIDE LAYER ON AN IRON, FERROUS ALLOY, OR CEMENTED CARRBICE ARTICLE, SAID ARTICLES CONTAINING AT LEAST 0.05% BY WEIGHT OF CARBON, WHICH COMPRISES PREPARING A MOLTEN TREATING BATH CONSISTING ESSENTIALLY OF BORIC ACID OR A BORATE AND A METALLIC ELEMENT DISSOLVED THEREIN, SAID METALLIC ELEMENT BEING SELECTED FROM THE GROUP CONSISTNG OF VANADIUM, NIOBIUM AND TANTALUM; IMMERSING SAID ARTICLE INTO SAID MOLTEN TREATING BATH; MAINTAINING SAID ARTICLE IN SAID MOLTEN TREATING BATH TO FORM A CARBIDE LAYER OF SAID METALLIC ELEMENT ON THE SURFACE OF SAID ARTICLE, AND REMOVING SAID ARTICLE FROM THE MOLTEN TREATING BATH; THE IMPROVEMENT WHEREIN SAID MOLTEN TREATING BATH IS PREPARED BY THE METHOD WHICH COMPRISES HEATING A BORIC ACID OR A BORATE TO ITS MOLTEN STATE TO FORM A MOLTEN BATH; DIPPING A METAL BLOCK CONTAINING AT LEAST ONE ELEMENT SELECTED FROM THE GROUP CONSISTING OF VANADIUM, NIOBIUM AND TANTALUM, AND APPLYING AN ELECTRIC CURRENT TO THE MOLTEN BATH THROUGH SAID METAL BLOCK AS THE ANODE AND AN ELECTRIC CONDUCTIVE MATERIAL, WHICH IS IN CONTACT WITH THE MOLTEN BATH AS THE CATHODE, TO ANODICALLY DISSOLVE SAID METAL BLOCK.
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein said borate is selected from the group consisting of sodium borate and potassium borate.
Claim 4
Dependent Claim
14 words
A method according to claim 1, wherein said metal block is a metallic alloy.
Claim 5
Dependent Claim
14 words
A method according to claim 3, wherein said metallic alloy is a ferrous alloy.
Claim 6
Dependent Claim
32 words
A method according to claim 1, wherein said ferrous alloy article is made of one selected from the group consisting of carbon steel and alloy steel containing at least 0.05% of carbon.
Claim 7
Dependent Claim
20 words
A method according to claim 1, wherein said cemented carbide article is made of a sintered tungsten carbide containing cobalt.
Claim 8
Dependent Claim
23 words
A method according to claim 1, wherein said treating molten bath contains at least 1% by weight of the V-a group element dissolved.
Claim 9
Dependent Claim
41 words
A method according to claim 1, wherein the electric current density of the anode is selected in a range from 0.2 to 5 A/cm2 and said metal block is anodically dissolved for a time ranging from 30 minutes to 5 hours.
Claim 10
Dependent Claim
52 words
A method according to claim 8, wherein the treating bath contains at least 1% by weight of the V-a group element dissolved in the molten treating bath and wherein said article is maintained in the molten treating bath for 1 to 30 hours and at a temperature ranging from 800* to 1100*C.
Claim 11
Dependent Claim
26 words
A method according to claim 1, wherein a vessel containing the molten bath is used as the cathode during the step of applying the electric current.
Claim 12
Dependent Claim
37 words
A method according to claim 1, wherein during the step of maintaining the article in the molten treating bath, said metal block is again anodically dissolved for supplying the V-a group elements into the molten treating bath.
Claim 13
Dependent Claim
29 words
A method according to claim 1, wherein said article is maintained in the treating molten bath for 1 to 30 hours at a temperature ranging from 800 to 1,100*C.
Claim 14
Dependent Claim
27 words
A method according to claim 1, wherein said treating molten bath contains chloride or fluoride of alkali metal for lowering the viscosity of the treating molten bath.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |