US3898052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion resistant coating system for ferrous metal articles having brazed joints
Assignee: Chromalloy Gas Turbine Corp
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Filing: 1974-10-18
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Granted: 1975-08-05
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Expires: 1994-10-18
Abstract
Abstract Ferrous metal articles, such as stainless steel articles, characterized by at least one brazed joint, in which the braze is a non-ferrous alloy are aluminized by first selectively coating the braze alloy with an aluminide-forming metal, such as nickel, and then thermally diffusing aluminum over the entire surface of the article including the selectively coated braze, such that a sacrificial corrosion resistant coating is produced wherein the aluminum coating on the ferrous metal surface is characterized by the presence of iron aluminide, and wherein the aluminum coating on the metal-coated braze is characterized by the presence of metal aluminide, such as nickel aluminide. The aluminide coatings are further enhanced by the application of a non-metallic coating, e.g., a conversion coating.
Inventors
- 👤 Michael F Dean
- 👤 Hossein Borougerdi
- 👤 John A Puchot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:27
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/30; C; C23; C23C; C23C10/00; C23C10/02; C23C10/28; C23C10/34; C23C10/36; C23C10/48; C23C10/50; C23C10/60; C23C18/00; C23C18/16; C23C18/18; C23C18/1803; C23C18/1824; C23C18/1837; C23C18/1841; C23C18/31; C23C18/32; C23C18/34; C23C18/36; C23F; C23F13/00; C23F13/02; F; F01; F01D; F01D5/00; F01D5/12; F01D5/28; F01D5/288; F02; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027; Y; Y02; Y02T; Y02T50/00; Y02T50/60; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9335; Y10S428/941; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12611; Y10T428/12771; Y10T428/12861; Y10T428/12889; Y10T428/12896; Y10T428/12903; Y10T428/12951; Y10T428/12972
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
148 words
A STAINLESS STEEL ARTICLE HAVING AT LEAST ONE BRAZED JOINT, THE BRAZE OF SAID JOINT BEING FORMED OF A NON-FERROUS BRAZING ALLOY OF MELTING POINT RANGING FROM ABOUT 1,125* TO 1,925*F, SAID BRAZE BEING CHARACTERIZED BY THE PRESENCE OF AN ALUMINIDE-FORMING METAL SELECTED FROM THE GROUP CONSISTING OF NICKEL, COBAT, IRON, TITANIUM, CHROMIUM, MANGANESE, MOLYBDENUM AND VANADIUM AT THE SURFACE THEREOF, THE STAINLESS STEEL ARTICLE HAVING A THERMALLY DIFFUSED ALUMINUM COATING ON SUBSTANTIALLY THE ENTIRE SURFACE OF SAID ARTICLE, THE COATING ON THE STAINLESS STEEL SURFACE OUTSIDE THE BRAZE BEING CHARACTERIZED BY THE PRESENCE OF IRON ALUMINIDE, THE ALUMINUM COATING ON THE BRAZE BEING CHARACTERIZED BY THE PRESENCE OF AN ALUMINIDE OF SAID METAL GROUP, THE THERMALLY DIFFUSED ALUMINUM COATING ALSO HAVING BONDED THERETO A CURED NON-METALLIC BARRIER LAYER FORMED FROM A SILICATE SELECTED FROM THE GROUP CONSISTING OF SODIUM SILICATE, POTASSIUM SILICATE, LITHIUM SILICATE AND ETHYL SILICATE.
Claim 2
Dependent Claim
148 words
A STAINLESS STEEL ARTICLE HAVING AT LEAST ONE BRAZED JOINT, THE BRAZE OF SAID JOINT BEING FORMED OF A NON-FERROUS BRAZING ALLOY OF MELTING POINT RANGING FROM ABOUT 1,125* TO 1,925*F, SAID BRAZE BEING CHARACTERIZED BY THE PRESENCE OF AN ALUMINIDE-FORMING METAL SELECTED FROM THE GROUP CONSISTING OF NICKEL, COBAT, IRON, TITANIUM, CHROMIUM, MANGANESE, MOLYBDENUM AND VANADIUM AT THE SURFACE THEREOF, THE STAINLESS STEEL ARTICLE HAVING A THERMALLY DIFFUSED ALUMINUM COATING ON SUBSTANTIALLY THE ENTIRE SURFACE OF SAID ARTICLE, THE COATING ON THE STAINLESS STEEL SURFACE OUTSIDE THE BRAZE BEING CHARACTERIZED BY THE PRESENCE OF IRON ALUMINIDE, THE ALUMINUM COATING ON THE BRAZE BEING CHARACTERIZED BY THE PRESENCE OF AN ALUMINIDE OF SAID METAL GROUP, THE THERMALLY DIFFUSED ALUMINUM COATING ALSO HAVING BONDED THERETO A CURED NON-METALLIC BARRIER LAYER FORMED FROM A SILICATE SELECTED FROM THE GROUP CONSISTING OF SODIUM SILICATE, POTASSIUM SILICATE, LITHIUM SILICATE AND ETHYL SILICATE.
Claim 3
Dependent Claim
127 words
A stainless steel article having at least one brazed joint, the braze of said joint being formed of a non-ferrous brazing alloy of melting point ranging from about 1,125* to 1,925*F, said braze being characterized by the presence of nickel at the surface thereof, the stainless steel article having a thermally diffused aluminum coating on substantially the entire surface of said article. the coating on the stainless steel surface outside the braze being characterized by the presence of iron aluminide, the aluminum coating on the braze being characterized by the presence of nickel aluminide, the thermally diffused aluminum coating also having bonded thereto a cured non-metallic barrier layer formed from a silicate selected from the group consisting of sodium silicate, potassium silicate, lithium silicate and ethyl silicate.
Claim 4
Dependent Claim
127 words
A stainless steel article having at least one brazed joint, the braze of said joint being formed of a non-ferrous brazing alloy of melting point ranging from about 1,125* to 1,925*F, said braze being characterized by the presence of nickel at the surface thereof, the stainless steel article having a thermally diffused aluminum coating on substantially the entire surface of said article. the coating on the stainless steel surface outside the braze being characterized by the presence of iron aluminide, the aluminum coating on the braze being characterized by the presence of nickel aluminide, the thermally diffused aluminum coating also having bonded thereto a cured non-metallic barrier layer formed from a silicate selected from the group consisting of sodium silicate, potassium silicate, lithium silicate and ethyl silicate.
Claim 5
Dependent Claim
35 words
The stainless steel article of claim 2, wherein the non-ferrous brazing alloy has a melting point of about 1,175* to 1, 850*F and wherein said brazing alloy is either a copper-base, silver-base or gold-base alloy.
Claim 6
Dependent Claim
24 words
The staniless steel article of claim 2, wherein said non-metallic barrier layer also includes a chromate and a phosphate of at least one metal.
Claim 7
Dependent Claim
26 words
The stainless steel article of claim 4, wherein said chromates and phosphates of said at least one metal are chromates and phosphates of aluminum and magnesium.
Claim 8
Dependent Claim
20 words
The article of manufacture of claim 5, wherein the silicate of the non-metallic barrier layer is derived from sodium silicate.
Claim 9
Dependent Claim
20 words
The article of manufacture of claim 5, wherein the silicate of the non-metallic barrier layer is derived from potassium silicate.
Claim 10
Dependent Claim
115 words
A stainless steel article having at least one brazed joint, the braze of said joint being formed of a non-ferrous brazing alloy of melting point ranging from about 1,125* to 1,925*F, said braze being characterized by the presence of an aluminide-forming metal selected from the group consisting of nickel, cobalt, iron, titanium, chromium, manganese, molybdenum and vanadium at the surface thereof, the stainless steel article having a thermally diffused aluminum coating on the whole surface of said article, the coating on the stainless steel surface outside the braze area being characterized by the presence of iron aluminide, the aluminum coating on the braze being characterized by the presence of an aluminide of said metal group.
Claim 11
Dependent Claim
115 words
A stainless steel article having at least one brazed joint, the braze of said joint being formed of a non-ferrous brazing alloy of melting point ranging from about 1,125* to 1,925*F, said braze being characterized by the presence of an aluminide-forming metal selected from the group consisting of nickel, cobalt, iron, titanium, chromium, manganese, molybdenum and vanadium at the surface thereof, the stainless steel article having a thermally diffused aluminum coating on the whole surface of said article, the coating on the stainless steel surface outside the braze area being characterized by the presence of iron aluminide, the aluminum coating on the braze being characterized by the presence of an aluminide of said metal group.
Claim 12
Dependent Claim
95 words
A stainless steel article having at least one brazed joint, the braze of said joint being formed of a non-ferrous brazing alloy of melting point ranging from about 1,125* to 1,925* F, said braze being characterized by the presence of nickel at the surface thereof, the stainless steel article having a thermally diffused aluminum coating on the whole surface of said article, the coating on the stainless steel surface outside the braze area being characterized by the presence of iron aluminide, the aluminum coating on the braze being characterized by the presence of nickel aluminide.
Claim 13
Dependent Claim
95 words
A stainless steel article having at least one brazed joint, the braze of said joint being formed of a non-ferrous brazing alloy of melting point ranging from about 1,125* to 1,925* F, said braze being characterized by the presence of nickel at the surface thereof, the stainless steel article having a thermally diffused aluminum coating on the whole surface of said article, the coating on the stainless steel surface outside the braze area being characterized by the presence of iron aluminide, the aluminum coating on the braze being characterized by the presence of nickel aluminide.
Claim 14
Dependent Claim
35 words
The stainless steel article of claim 7, wherein the non-ferrous brazing alloy has a melting point of about 1,175* to 1, 850*F and wherein said brazing alloy is either a copper-base, silver-base or gold-base alloy.
References Cited (Backward Citations)
US3597172A
Cited
US3859061A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |