Patent US3719518A successfully refreshed from Google Patents.
US3719518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of forming a carbide layer of vanadium, niobium or tantalum upon a steel surface
Assignee: Toyota Central R&D Labs Inc
•
Filing: 1970-10-29
•
Granted: 1973-03-06
•
Expires: 1990-10-29
Abstract
Abstract A process for the surface treatment of an iron or iron alloy stock comprising heating a mixture of boric acid or borate. A V-a group element of the periodic table consisting of vanadium, niobium and tantalum, or a substance containing the same, and carbon or a carbon containing substance to its fusing state in a bath vessel, and immersing the stock in the molten bath of said mixture, thereby forming a carbide layer of said element on the stock thus treated. The present invention can be performed without adding carbon to a mixture in the case when either said stock or said vessel includes carbon.
Inventors
- 👤 N Komatsu
- 👤 T Arai
- 👤 M Mizutani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:33
CPC Classifications
C; C23; C23C; C23C12/00; C23C12/02; C23C10/00; C23C10/18; C23C10/20; C23C10/24
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
89 words
A process for the surface treatment of an iron or iron alloy stock, comprising the steps of heating a mixture consisting essentially of boric acid or a borate, at least one element of group V-a of the Periodic table consisting of vanadium, niobium and tantalum or a substance containing the same, and carbon or a carbon-containing substance to its fusing state in a bath vessel, and immersing the stock in the molten bath of said mixture, thereby forming a carbide layer of said elEment on the stock thus treated.
Claim 2
Dependent Claim
89 words
A process for the surface treatment of an iron or iron alloy stock, comprising the steps of heating a mixture consisting essentially of boric acid or a borate, at least one element of group V-a of the Periodic table consisting of vanadium, niobium and tantalum or a substance containing the same, and carbon or a carbon-containing substance to its fusing state in a bath vessel, and immersing the stock in the molten bath of said mixture, thereby forming a carbide layer of said elEment on the stock thus treated.
Claim 3
Dependent Claim
13 words
A process according to claim 1, wherein borax is used as said borate.
Claim 4
Dependent Claim
17 words
A process according to claim 1, wherein said substance containing V-a group element is a ferro-alloy thereof.
Claim 5
Dependent Claim
22 words
A process according to claim 1, wherein 1 to 70 percent by weight of V-a group element is included in said mixture.
Claim 6
Dependent Claim
20 words
A process according to claim 1, wherein at least 0.03 percent by weight of carbon is included in said mixture.
Claim 7
Dependent Claim
19 words
A process according to claim 1, wherein said heating step is performed within the range of 800*C to 1,100*C.
Claim 8
Dependent Claim
34 words
A process according to claim 1, wherein at least one member selected from the group consisting of a hydroxide or halide of sodium or potassium and a phosphorus oxide is added to said mixture.
Claim 9
Dependent Claim
24 words
A process according to claim 1, wherein 42 to 95 percent by weight of said boric acid or borate is included in said mixture.
Claim 10
Dependent Claim
25 words
A process according to claim 6, wherein said stock is immersed in said mixture for a period of time of from 1 to 30 hours.
Claim 11
Dependent Claim
89 words
A process for the surface treatment of an iron or iron alloy stock, comprising the steps of heating a mixture consisting essentially of boric acid or a borate and at least one element of Group V-a of the Periodic table consisting of vanadium, niobium and tantalum or a substance containing the same, to its fusing state in a vessel containing carbon as its main ingredient, and immersing the stock in the molten bath of said mixture, thereby forming a carbide layer of said element on the stock thus treated.
Claim 12
Dependent Claim
89 words
A process for the surface treatment of an iron or iron alloy stock, comprising the steps of heating a mixture consisting essentially of boric acid or a borate and at least one element of Group V-a of the Periodic table consisting of vanadium, niobium and tantalum or a substance containing the same, to its fusing state in a vessel containing carbon as its main ingredient, and immersing the stock in the molten bath of said mixture, thereby forming a carbide layer of said element on the stock thus treated.
Claim 13
Dependent Claim
13 words
A process according to claim 10, wherein said vessel is made of graphite.
Claim 14
Dependent Claim
88 words
A process for the surface treatment of an iron or iron alloy stock, comprising the steps of heating a mixture consisting essentially of boric acid or a borate, at least one element of Group V-a of the Periodic table consisting of vanadium, niobium and tantalum or a substance containing the same to its fusing state in the vessel, and immersing an iron or iron alloy stock containing carbon in the molten bath of said mixture, thereby forming a carbide layer of said element on the stock thus treated.
Claim 15
Dependent Claim
88 words
A process for the surface treatment of an iron or iron alloy stock, comprising the steps of heating a mixture consisting essentially of boric acid or a borate, at least one element of Group V-a of the Periodic table consisting of vanadium, niobium and tantalum or a substance containing the same to its fusing state in the vessel, and immersing an iron or iron alloy stock containing carbon in the molten bath of said mixture, thereby forming a carbide layer of said element on the stock thus treated.
Claim 16
Dependent Claim
26 words
A process according to claim 12, wherein said substance containing a group V-a element of the Periodic table is a ferro-alloy containing a group V-a element.
Claim 17
Dependent Claim
24 words
A process according to claim 12, wherein said stock is selected from the group consisting of high-carbon steel, high-carbon alloy steel and cast iron.
Claim 18
Dependent Claim
30 words
A process according to claim 12, wherein said stock is a low-carbon stock and is case-hardened prior to said immersing step to increase the carbon content on the surface thereof.
Claim 19
Dependent Claim
13 words
A process according to claim 12, wherein borax is used as said borate.
Claim 20
Dependent Claim
23 words
A process according to claim 12, wherein 1 to 70 percent by weight of said V-a group element is included in said mixture.
Claim 21
Dependent Claim
20 words
A process according to claim 12, wherein said heating step is performed within the range of 800*C to 1,100* C.
Claim 22
Dependent Claim
34 words
A process according to claim 12, wherein at least one member selected from the group consisting of a hydroxide or halide of sodium or potassium and a phosphorus oxide is added to said mixture.
Claim 23
Dependent Claim
24 words
A process according to claim 12, wherein 42 to 95 percent by weight of said boric acid or borate is included in said mixture.
References Cited (Backward Citations)
US1796248A
Cited
GB625192A
Cited
US2492805A
Cited
GB646645A
Cited
US2568860A
Cited
GB637635A
Cited
GB722915A
Cited
US2694647A
Cited
US2846345A
Cited
US2885301A
Cited
US2929741A
Cited
US2926111A
Cited
US3203811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |