US3663315A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas carburization and carbonitriding
Assignee: Union Carbide Corp
•
Filing: 1969-03-26
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Granted: 1972-05-16
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Expires: 1989-03-26
Abstract
Abstract The formation of soot is avoided during gas carburization or carbonitriding of steel having a carbon content of from 0.10 0.40 percent in an atmosphere of nitrogen and a hydrocarbon gas, such as natrual gas by the use of a barium, calcium or strontium containing inhibitor, for example, barium hydroxide.
Inventors
- 👤 Maurice F Hoffman
- 👤 Abram L Hodge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:22
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/28; C23C8/30; C23C8/32; C23C8/08; C23C8/20; C23C8/22
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
14 words
The method of claim 1 wherein the case hardening consists of carburizing said steel.
Claim 2
Dependent Claim
17 words
The method of claim 1 wherein said inert carrier gas contains hydrogen in addition to the nitrogen.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein said case hardening consists of carbonitriding said steel and wherein said gaseous atmosphere also contains ammonia.
Claim 4
Dependent Claim
37 words
The method of claim 1 wherein said gaseous atmosphere is passed over a bed of said inhibitor having a temperature of at least 200* F. prior to coming in contact with the steel to be case hardened.
Claim 5
Dependent Claim
34 words
The method of claim 1 wherein said inhibitor, in finely divided powdered form, is dusted on the surface of the steel to be case hardened prior to coming in contact with said gaseous atmosphere.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein the inhibitor is a compound, metal or alloy of barium.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein the inhibitor is barium hydroxide.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein the hydrocarbon gas is natural gas.
Claim 9
Dependent Claim
30 words
The method of claim 9 wherein said gaseous atmosphere comprises about 2 to 12 percent by volume hydrocarbon gas and the remaining 88 to 98 percent is the carrier gas.
References Cited (Backward Citations)
US246861A
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US1848958A
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US1958575A
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US1932032A
Cited
US2089545A
Cited
US2240146A
Cited
GB573085A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |