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US4531981A
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US
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Component possessing high resistance to corrosion and oxidation, composed of a dispersion-hardened superalloy, and process for its manufacture
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1984-02-01
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Granted: 1985-07-30
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Expires: 2004-02-01
Abstract
Abstract A component possessing high resistance to corrosion and oxidation, composed of a dispersion-hardened superalloy having a high creep strength, comprises a coarse-grained core (1) which has high strength at high temperatures, and a fine-grained skin zone (2) which forms a case. The component is manufactured with the aid of a heat-treatment, or thermomechanical treatment, in a manner such that, starting from a fine-grained initial condition, the skin zone (2) is restrained from participating in the recrystallization which leads to the formation of coarse grains in the core (1).
Inventors
- 👤 Robert Singer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:09
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/34; C21D1/42; C22; C22F; C22F1/00; C22F1/10; Y; Y02; Y02P; Y02P10/00; Y02P10/25; Y10; Y10S; Y10S148/00; Y10S148/902
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
75 words
Component possessing high resistance to corrosion and oxidation, composed of a dispersion-hardened superalloy, characterized in that its structure comprises a coarse-grained core (1), in which the average crystallite size ranges from 0.2 to 50 mm in the longitudinal axis, and from 0.1 to 10 mm in the transverse axis, and a fine-grained skin zone (2) which is 20 to 2000μ thick, has an average crystallite size ranging from 0.1 to 5μ, and forms a case.
Claim 2
Dependent Claim
75 words
Component possessing high resistance to corrosion and oxidation, composed of a dispersion-hardened superalloy, characterized in that its structure comprises a coarse-grained core (1), in which the average crystallite size ranges from 0.2 to 50 mm in the longitudinal axis, and from 0.1 to 10 mm in the transverse axis, and a fine-grained skin zone (2) which is 20 to 2000μ thick, has an average crystallite size ranging from 0.1 to 5μ, and forms a case.
Claim 3
Dependent Claim
16 words
Component according to claim 1, characterized in that it is a blade of a thermal turbomachine.
Claim 4
Dependent Claim
54 words
A process for the manufacture of a component possessing high resistance to corrosion and oxidation, composed of a dispersion-hardened superalloy, comprising subjecting a workpiece in a fine-grained condition to a heat treatment and developing a coarse grained condition in the core while retaining the fine grained condition of the skin zone of said workpiece.
Claim 5
Dependent Claim
54 words
A process for the manufacture of a component possessing high resistance to corrosion and oxidation, composed of a dispersion-hardened superalloy, comprising subjecting a workpiece in a fine-grained condition to a heat treatment and developing a coarse grained condition in the core while retaining the fine grained condition of the skin zone of said workpiece.
Claim 6
Dependent Claim
31 words
The process of claim 3 wherein said heat treatment comprises heating said skin zone slightly below its recrystallization temperature while heating said core at a temperature 150° to 350° C. lower.
Claim 7
Dependent Claim
45 words
The process of claim 3 further comprising forging said workpiece in a die preheated to a temperature no greater than 350° C. below the recrystallization temperature of said workpiece and further subjecting said workpiece to an annealing treatment above the recrystallization temperature of said workpiece.
Claim 8
Dependent Claim
42 words
The process of claim 3 wherein said heat treatment comprises effectuating a 10% reduction in cross-section at the thickest point of the workpiece by heating said skin and core zones of said workpiece to forging temperatures of 1100° and 900° C., respectively.
Claim 9
Dependent Claim
44 words
The process of claim 6 further comprising forging said workpiece in a die preheated to a temperature less than 350° C. below the recrystallization temperature of said workpiece and further subjecting said workpiece to an annealing treatment above the recrystallization temperature of said workpiece.
Claim 10
Dependent Claim
17 words
The process of claim 7 wherein said workpiece is forged in a die preheated to 1050° C.
Claim 11
Dependent Claim
36 words
The process of claim 8, wherein said annealing treatment comprises zone-annealing said workpiece at 1280° C., wherein the temperature front advances 1 mm/min in the longitudinal direction, and further wherein the temperature gradient is 10° C./mm.
Claim 12
Dependent Claim
45 words
The process of claim 3 wherein said heat treatment comprises (a) forging said workpiece below its recrystallization temperature; and (b) heating said skin zone of said workpiece to a temperature slightly below its recrystallization temperature at a heating rate of 50° C./min. to 250° C./min.
Claim 13
Dependent Claim
28 words
The process of claim 10 wherein said said skin zone is heated for less than 30 minutes by a radiant energy means coupled with a thermal conduction means.
Claim 14
Dependent Claim
22 words
The process of claim 11 wherein said workpiece is further subjected to an annealing treatment at a temperature above its recrystallization temperature.
Claim 15
Dependent Claim
55 words
The process of claim 12, wherein said workpiece is forged under isothermal conditions and further wherein said skin zone is heated, at a heating rate of 200° C./min., to a temperature of 1140° C., heating said skin zone at 1140° C. for 4 minutes, and then annealing said workpiece for 1 hour at 1280° C.
Claim 16
Dependent Claim
44 words
The process of claim 3 wherein said heat treatment comprises induction heating said workpiece while simultaneously cooling said skin zone such that said core is heated at a temperature above the recrystallization temperature while said skin zone is heated slightly below its recrystallization temperature.
Claim 17
Dependent Claim
24 words
The process of claim 14, wherein said core is heated between 1230° to 1280° C., and said skin zone is heated at 1140° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-29 | 1989-01-28 | 1989-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-29 | 1993-01-28 | 1993-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-29 | 1997-01-28 | 1997-07-30 | $7700.00 | Window Closed / Lapsed |