Patent US3901689A successfully refreshed from Google Patents.
US3901689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing chromium-chromium carbide powder
Assignee: Praxair ST Technology Inc
•
Filing: 1974-06-25
•
Granted: 1975-08-26
•
Expires: 1994-06-25
Abstract
Abstract A composite powder for use in producing articles or coatings having unique wear and frictional characteristics consisting essentially of a chromium matrix with at least one chromium carbide taken from the class of carbides consisting of Cr23 C6; Cr7 C3; and Cr3 C2 and each particle containing from about 0.2 wt % to about 5.4 wt % carbon. Also described are processes for making the powder and an article coated by passing the powder through a plasma or detonation gun.
Inventors
- 👤 John Franklin Pelton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:30
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/04; C22C1/05; C22C1/051; C22C1/053; C22C1/055; C23; C23C; C23C4/00; C23C4/04; C23C4/06; F; F02; F02B; F02B55/00; F02B55/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
81 words
A METHOD FOR PRODUCING A POWDER COMPRISING: A. HEATING A SOURCE OF CHROMIUM WITH A SOURCE OF CARBON IN A NON-OXIDIZING ENVIRONMENT UNTIL THE CARBON DIFFUSES AND REACTS WITH THE CHROMIUM, B. COMMINUTING THE PRODUCT FORMED IN STEP A TO A POWDER CONTAINING FROM ABOUT 0.2 WT % TO ABOUT 5.4 WT % CARBON AND WHEREIN SUBSTANTIALLY EVERY PARTICLE OF SAID POWDER CONSISTS ESSENTIALLY OF CHROMIUM AND AT LEAST ONE CHROMIUM CARBIDE TAKEN THE CLASS CONSISTING OF CR23C6, CR7C3 AND CR3C2.
Claim 2
Independent Claim
81 words
A METHOD FOR PRODUCING A POWDER COMPRISING: A. HEATING A SOURCE OF CHROMIUM WITH A SOURCE OF CARBON IN A NON-OXIDIZING ENVIRONMENT UNTIL THE CARBON DIFFUSES AND REACTS WITH THE CHROMIUM, B. COMMINUTING THE PRODUCT FORMED IN STEP A TO A POWDER CONTAINING FROM ABOUT 0.2 WT % TO ABOUT 5.4 WT % CARBON AND WHEREIN SUBSTANTIALLY EVERY PARTICLE OF SAID POWDER CONSISTS ESSENTIALLY OF CHROMIUM AND AT LEAST ONE CHROMIUM CARBIDE TAKEN THE CLASS CONSISTING OF CR23C6, CR7C3 AND CR3C2.
Claim 3
Independent Claim
88 words
A method for producing a powder comprising: A. mixing a source of chromium powder with a source of carbon; B. heating said mixture in a non-oxidizing environment until the carbon diffuses and reacts with the chromium; and C. comminuting the product formed in Step (B) to a powder containing from about 0.2 wt % to about 5.4 wt % carbon and wherein substantially every particle of said powder consists essentially of chromium and at least one chromium carbide taken from the class consisting of Cr23C6; Cr7C3 and Cr3C2.
Claim 4
Independent Claim
88 words
A method for producing a powder comprising: A. mixing a source of chromium powder with a source of carbon; B. heating said mixture in a non-oxidizing environment until the carbon diffuses and reacts with the chromium; and C. comminuting the product formed in Step (B) to a powder containing from about 0.2 wt % to about 5.4 wt % carbon and wherein substantially every particle of said powder consists essentially of chromium and at least one chromium carbide taken from the class consisting of Cr23C6; Cr7C3 and Cr3C2.
Claim 5
Dependent Claim
15 words
Method according to claim 2 wherein the source of chromium is Cr203 or chromium metal.
Claim 6
Dependent Claim
26 words
Method according to claim 2 wherein the source of carbon is elemental carbon or a carbide of chromium containing a greater percentage of carbon than Cr23C6.
Claim 7
Dependent Claim
27 words
Method according to claim 2 wherein said mixture is heated to a temperature in the range of from 1000*to 1400*C for a period of from 1-50 hours.
Claim 8
Dependent Claim
12 words
Method according to claim 2 wherein said nonoxidizing environment is a vacuum.
Claim 9
Dependent Claim
11 words
Method according to claim 2 wherein said nonoxidizing environment is hydrogen.
Claim 10
Dependent Claim
15 words
Method according to claim 1 wherein said source of carbon is a carbon containing gas.
Claim 11
Dependent Claim
14 words
Method according to claim 8 wherein said carbon containing gas is a hydrocarbon gas.
References Cited (Backward Citations)
US3743499A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |