US4400224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming a carbide layer on the surface of a ferrous alloy article or a cemented carbide article
Assignee: Toyota Central R&D Labs Inc
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Filing: 1982-04-02
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Granted: 1983-08-23
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Expires: 2002-04-02
Abstract
Abstract A method for forming a carbide layer on the surface of a carbon-containing ferrous alloy article or a cemented carbide article in a molten treating bath. The bath is prepared by introducing 5 to 20% by weight of alumina into molten boric acid or borate bath and a carbide-forming element dissolved therein. By employing the treating bath of this invention, the life of the bath can be remarkably improved, and no sintered substance of undissolved carbide-forming element is produced in the treating bath. Further, it is possible to reduce markedly the corrosion of the article and of the vessel holding the bath.
Inventors
- 👤 Tohru Arai
- 👤 Hironori Fujita
- 👤 Yasuo Takada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:00
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/18; C23C10/20; C23C10/24
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
128 words
A method for forming a carbide layer on the surface of a carbon-containing ferrous alloy article or a cemented carbide article, comprising the steps of: (a) preparing a treating bath comprising molten boric acid or borate, a carbide-forming element dissolved therein and 5 to 20% by weight, based on the whole weight of the bath, of alumina; (b) keeping said treating bath at a temperature within the range from 1050° C. to a temperature lower than the melting point of the article to be treated; (c) immersing the article into the molten treating bath; (d) maintaining said article in said molten treating bath to form a carbide layer of said carbide-forming element on the surface of said article; and (e) removing said article from said molten treating bath.
Claim 2
Independent Claim
128 words
A method for forming a carbide layer on the surface of a carbon-containing ferrous alloy article or a cemented carbide article, comprising the steps of: (a) preparing a treating bath comprising molten boric acid or borate, a carbide-forming element dissolved therein and 5 to 20% by weight, based on the whole weight of the bath, of alumina; (b) keeping said treating bath at a temperature within the range from 1050° C. to a temperature lower than the melting point of the article to be treated; (c) immersing the article into the molten treating bath; (d) maintaining said article in said molten treating bath to form a carbide layer of said carbide-forming element on the surface of said article; and (e) removing said article from said molten treating bath.
Claim 3
Dependent Claim
13 words
A method according to claim 1, wherein said alumina is in powder form.
Claim 4
Dependent Claim
29 words
A method according to claim 1, wherein said carbide-forming element is a member selected from the group consisting of a Va group element of the Periodic Table and chromium.
Claim 5
Dependent Claim
14 words
A method according to claim 3, wherein said carbide-forming element is in alloy form.
Claim 6
Dependent Claim
30 words
A method according to claim 3, wherein said carbide-forming element is in oxide form and said treating bath further comprises a boron-supplying material wherein boron is not bound to oxygen.
Claim 7
Dependent Claim
20 words
A method according to claim 4, wherein said borate is borax and said carbide-forming element in alloy form is Fe-V.
Claim 8
Dependent Claim
20 words
A method according to claim 4, wherein said borate is borax and said carbide-forming element in alloy form is Fe-Nb.
Claim 9
Dependent Claim
17 words
A method according to claim 3, wherein said borate is borax and said carbide-forming element is chromium.
Claim 10
Dependent Claim
31 words
A method according to claim 5, wherein said borate is borax, said carbide forming element in oxide form is V 2 O 5 and said boron-supplying material is B 4 C.
Claim 11
Independent Claim
29 words
A method according to any one of claims 6 to 9, wherein the amount of said alumina is 10% by weight of the whole weight of said treating bath.
Claim 12
Dependent Claim
52 words
A treating material for forming a carbide layer on the surface of a carbon-containing ferrous alloy article or a cemented carbide article which is composed of boric acid or a borate, a carbide-forming element and from 5 to 20% by weight, based on the whole weight of the treating material, of alumina.
Claim 13
Dependent Claim
52 words
A treating material for forming a carbide layer on the surface of a carbon-containing ferrous alloy article or a cemented carbide article which is composed of boric acid or a borate, a carbide-forming element and from 5 to 20% by weight, based on the whole weight of the treating material, of alumina.
Claim 14
Dependent Claim
14 words
A treating material according to claim 11, wherein said alumina is in powder form.
Claim 15
Dependent Claim
30 words
A treating material according to claim 11, wherein said carbide-forming element is a member selected from the group consisting of a Va group element of the Periodic Table and chromium.
Claim 16
Dependent Claim
14 words
A treating material according to claim 13, wherein said carbide-forming element is an alloy.
Claim 17
Dependent Claim
31 words
A treating material according to claim 13, wherein said carbide-forming element is in oxide form and said treating material further comprises a boron-supplying material wherein boron is not bound to oxygen.
Claim 18
Dependent Claim
21 words
A treating material according to claim 14, wherein said borate is borax and said carbide-forming element in alloy form is Fe-V.
Claim 19
Dependent Claim
21 words
A treating material according to claim 14, wherein said borate is borax and said carbide-forming element in alloy form is Fe-Nb.
Claim 20
Dependent Claim
19 words
A treating material according to claim 13, wherein said borate is borax and said carbide forming element is chromium.
Claim 21
Dependent Claim
32 words
A treating material according to claim 15, wherein said borate is borax, said carbide forming element in oxide form is V 2 O 5 and said boron-supplying material is B 4 C.
Claim 22
Dependent Claim
31 words
A treating material according to any one of claims 16 to 19, wherein the amount of said alumina is 10% by weight based on the whole weight of said treating material.
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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) | 1986-08-22 | 1987-02-21 | 1987-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-22 | 1991-02-21 | 1991-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-22 | 1995-02-21 | 1995-08-23 | $7700.00 | Window Closed / Lapsed |