Patent US4238251A successfully refreshed from Google Patents.
US4238251A
Expired / Lapsed
US
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Zirconium alloy heat treatment process and product
Assignee: General Electric Co
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Filing: 1977-11-18
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Granted: 1980-12-09
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Expires: 1997-11-18
Abstract
Abstract Zirconium-base alloy channels and fuel cladding tubes having unique resistance to accelerated pustular corrosion in the boiling water reactor environment are produced by a heat treatment causing segregation of intermetallic particulate precipitate phase in two dimensional arrays preferably located along grain boundaries and subgrain boundaries throughout the alloy body.
Inventors
- 👤 Cedric D. Williams
- 👤 Andrew W. Urquhart
- 👤 James L. Walker
- 👤 Richard A. Proebstle
- 👤 Timothy J. Black
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:07
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/16; C22F1/18; C22F1/186; Y; Y10; Y10S; Y10S376/00; Y10S376/90
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
As an article of manufacture, a zirconium-base alloy structural component produced by the method including, in addition to hot and cold working and annealing steps, the steps of heating said structural component to 825° C. to 1100° C., maintaining said structural component at said temperature for at least about 3 seconds to initiate alpha to beta transformation, cooling said structural component to about 700° C. at a rate of at least about 20° C. per second to precipitate intermetallic phase material dissolved during the heating step in two dimensional arrays in an amount effective to at least double the corrosion-limited lifetime of said structural component and retaining substantially all said two dimensional arrays during any subsequent processing steps executed through and including installing said structural component in a boiling water reactor.
Claim 2
Dependent Claim
131 words
As an article of manufacture, a zirconium-base alloy structural component produced by the method including, in addition to hot and cold working and annealing steps, the steps of heating said structural component to 825° C. to 1100° C., maintaining said structural component at said temperature for at least about 3 seconds to initiate alpha to beta transformation, cooling said structural component to about 700° C. at a rate of at least about 20° C. per second to precipitate intermetallic phase material dissolved during the heating step in two dimensional arrays in an amount effective to at least double the corrosion-limited lifetime of said structural component and retaining substantially all said two dimensional arrays during any subsequent processing steps executed through and including installing said structural component in a boiling water reactor.
Claim 3
Dependent Claim
20 words
The article of claim 1 which is a channel and in which the intermetallic precipitate phase is Zr(Cr,Fe) 2 .
Claim 4
Dependent Claim
18 words
The article of claim 1 in which the intermetallic precipitate phases are Zr(Cr,Fe) 2 , Zr 2 (Ni,Fe).
Claim 5
Dependent Claim
136 words
In the method of producing a boiling water reactor structural component of a zirconium-base alloy including hot and cold working and annealing steps comprising a fabrication schedule, the combination of the steps of heating the structural component to 825° C. to 1100° C., maintaining the structural component at said temperature for at least about 3 seconds to initiate alpha to beta transformation, cooling the structural component to about 700° C. at a rate of at least about 20° C. per second to precipitate intermetallic phase material dissolved during the heating step in two dimensional arrays in an amount effective to at least double the corrosion-limited lifetime of said structural component and retaining substantially all said two dimensional arrays during any subsequent processing steps executed through and including installing said structural component in a boiling water reactor.
Claim 6
Dependent Claim
136 words
In the method of producing a boiling water reactor structural component of a zirconium-base alloy including hot and cold working and annealing steps comprising a fabrication schedule, the combination of the steps of heating the structural component to 825° C. to 1100° C., maintaining the structural component at said temperature for at least about 3 seconds to initiate alpha to beta transformation, cooling the structural component to about 700° C. at a rate of at least about 20° C. per second to precipitate intermetallic phase material dissolved during the heating step in two dimensional arrays in an amount effective to at least double the corrosion-limited lifetime of said structural component and retaining substantially all said two dimensional arrays during any subsequent processing steps executed through and including installing said structural component in a boiling water reactor.
Claim 7
Dependent Claim
25 words
The method of claim 4 in which the structural component is cooled to below 300° C. at the rate of approximately 250° C. per second.
Claim 8
Dependent Claim
35 words
The method of claim 4 in which from 25 percent to 50 percent of the total intermetallic particles are precipitated in two dimensional arrays located at alpha grain and sub-grain boundaries throughout the structural component.
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) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |