Patent US4024294A successfully refreshed from Google Patents.
US4024294A
Expired / Lapsed
US
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Protective coatings for superalloys
Assignee: General Electric Co
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Filing: 1975-03-10
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Granted: 1977-05-17
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Expires: 1995-03-10
Abstract
Abstract A protective coating is provided for nickel-base and cobalt-base superalloys which is highly resistant to corrosion and oxidation in a fused Na 2 SO 4 environment at elevated temperatures. The superalloy body is coated by physical vapor deposition with a composition consisting essentially of 50-80% by weight of cobalt and 20-50% by weight of chromium. Optionally, the body may then be coated with an overlayer of aluminum and heat treated to cause interdiffusion of aluminum into the undercoating and thereby enhance the hot corrosion and oxidation resistance of the superalloy body.
Inventors
- 👤 John R. Rairden, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:21
CPC Classifications
C; C23; C23C; C23C26/00; C23C14/00; C23C14/06; C23C14/14; C23C14/16
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
51 words
A method of improving the high temperature oxidation and corrosion resistance of a nickel-base or cobalt-base superalloy containing 9.5-19.0 percent chromium comprising coating said superalloy by physical vapor deposition with a composition consisting of, on a weight percent basis, from 50% cobalt and 50% chromium to 80% cobalt and 20% chromium.
Claim 2
Independent Claim
51 words
A method of improving the high temperature oxidation and corrosion resistance of a nickel-base or cobalt-base superalloy containing 9.5-19.0 percent chromium comprising coating said superalloy by physical vapor deposition with a composition consisting of, on a weight percent basis, from 50% cobalt and 50% chromium to 80% cobalt and 20% chromium.
Claim 3
Dependent Claim
11 words
The claim 1 method wherein said superalloy is a cobalt-base superalloy.
Claim 4
Independent Claim
49 words
A method of improving the high temperature oxidation and corrosion resistance of a nickel-base superalloy containing 9.5-19.0 percent chromium comprising coating said superalloy by physical vapor deposition with a composition consisting of, on a weight percent basis, from 50% cobalt and 50% chromium to 80% cobalt and 20% chromium.
Claim 5
Independent Claim
49 words
A method of improving the high temperature oxidation and corrosion resistance of a nickel-base superalloy containing 9.5-19.0 percent chromium comprising coating said superalloy by physical vapor deposition with a composition consisting of, on a weight percent basis, from 50% cobalt and 50% chromium to 80% cobalt and 20% chromium.
Claim 6
Dependent Claim
13 words
The claim 3 method wherein said coating has a thickness of 1-7 mils.
Claim 7
Dependent Claim
46 words
The claim 4 method wherein said superalloy contains 9.5-19.0% chromium, 8.5-18% cobalt, 2.9-5.5% aluminum, 2.9-5.0% titanium, 1.75-4.0% molybdenum, 0-4% tungsten, 0-1.75% tantalum, and 0-1% of vanadium, 0.08-0.18% carbon, 0.2-0.75% manganese, 0.2-0.75% silicon, 0-0.9% niobium, 0.2-0.50% iron, 0.005-0.015% boron, 0-0.1% zirconium, and the balance being essentially nickel.
Claim 8
Dependent Claim
23 words
The claim 5 method wherein said superalloy contains 16% chromium, 8.5% cobalt, 3.4% aluminum, 3.4% titanium, 1.75% molybdenum, 2.6% tungsten, and 1.75% tantalum.
Claim 9
Independent Claim
96 words
A method of improving the high temperature oxidation and corrosion resistance of a nickel-base or cobalt-base superalloy containing 9.5-19.0 percent chromium comprising the steps of: a. coating the superalloy body by physical vapor deposition with a first coating of a composition consisting of, on a weight percent basis, from 50% cobalt and 50% chromium to 80% cobalt and 20% chromium, b. subjecting the coated body to an overcoat of aluminum, and c. heat treating the duplex coating to cause interdiffusion of aluminum with the first coating to increase the oxidation and corrosion resistance of the coating.
Claim 10
Independent Claim
96 words
A method of improving the high temperature oxidation and corrosion resistance of a nickel-base or cobalt-base superalloy containing 9.5-19.0 percent chromium comprising the steps of: a. coating the superalloy body by physical vapor deposition with a first coating of a composition consisting of, on a weight percent basis, from 50% cobalt and 50% chromium to 80% cobalt and 20% chromium, b. subjecting the coated body to an overcoat of aluminum, and c. heat treating the duplex coating to cause interdiffusion of aluminum with the first coating to increase the oxidation and corrosion resistance of the coating.
Claim 11
Dependent Claim
11 words
The claim 7 method wherein said superalloy is a cobalt-base superalloy.
Claim 12
Independent Claim
94 words
A method of improving the high temperature oxidation and corrosion resistance of a nickel-base superalloy containing 9.5-19.0 percent chromium comprising the steps of: a. coating the superalloy body by physical vapor deposition with a first coating of a composition consisting of, on a weight percent basis, from 50% cobalt and 50% chromium to 80% cobalt and 20% chromium, b. subjecting the coated body to an overcoat of aluminum, and c. heat treating the duplex coating to cause interdiffusion of aluminum with the first coating to increase the oxidation and corrosion resistance of the coating.
Claim 13
Independent Claim
94 words
A method of improving the high temperature oxidation and corrosion resistance of a nickel-base superalloy containing 9.5-19.0 percent chromium comprising the steps of: a. coating the superalloy body by physical vapor deposition with a first coating of a composition consisting of, on a weight percent basis, from 50% cobalt and 50% chromium to 80% cobalt and 20% chromium, b. subjecting the coated body to an overcoat of aluminum, and c. heat treating the duplex coating to cause interdiffusion of aluminum with the first coating to increase the oxidation and corrosion resistance of the coating.
Claim 14
Dependent Claim
23 words
The claim 9 method wherein the first coating has a thickness of 1-7 mils and the overcoating has a thickness of 0.1-3.0 mils.
Claim 15
Dependent Claim
47 words
The claim 10 method wherein said superalloy contains 9.5-19.0% chromium, 8.5-18% cobalt, 2.9-5.5% aluminum, 2.9-5.0% titanium, 1.75-4.0% molybdenum, 0-4.0% tungsten, 0-1.75% tantalum, and 0-1% of vanadium, 0.08-0.18% carbon, 0.2-0.75% manganese, and 0.2-0.75% silicon, 0-0.9% niobium, 0.2-0.50% iron, 0.003-0.015% boron, 0-0.1% zirconium, and the balance being essentially nickel.
Claim 16
Dependent Claim
23 words
The claim 11 method wherein said superalloy contains 16% chromium, 8.5% cobalt, 3.4% aluminum, 3.4% titanium, 1.75% molybdenum, 2.6% tungsten, and 1.75% tantalum.
Claim 17
Dependent Claim
12 words
The claim 10 method wherein the overcoating is applied by pack cementation.
Claim 18
Dependent Claim
13 words
The claim 10 method wherein the overcoating is applied by electron beam evaporation.
Claim 19
Dependent Claim
22 words
The claim 10 method wherein the heat treatment is at a temperature of 1040-1230° C. for 0.25-5 hours in an inert atmosphere.
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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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |