US3866301A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming sheet material with excellent surface characteristics
Assignee: Allegheny Ludlum Corp
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Filing: 1973-06-28
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Granted: 1975-02-18
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Expires: 1993-06-28
Abstract
Abstract A method for making sheet material substantially free from surface imperfections is disclosed, which includes casting the metal into an ingot and subjecting the ingot to a temperature at which its creep resistance is low and to a gas pressure of at least 7,500 psi for a time sufficient to close internal pores and then slicing the ingot into sheets.
Inventors
- 👤 James A Salsgiver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:50
CPC Classifications
B; B23; B23P; B23P25/00; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49789; Y10T29/49972; Y10T29/4998; Y10T29/49988; Y10T29/49989
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
70 words
A process for forming sheet material substantially free from surface imperfections from brittle metal that cannot successfully be rolled comprising: A. casting an ingot of the brittle metal, B. maintaining the ingot at a non-damaging temperature at which the metal will creep and under a gas pressure of at least 7,500 psi for a period of time sufficient to substantially eliminate porosity, C. slicing the resultant non-porous ingot into sheets.
Claim 2
Dependent Claim
70 words
A process for forming sheet material substantially free from surface imperfections from brittle metal that cannot successfully be rolled comprising: A. casting an ingot of the brittle metal, B. maintaining the ingot at a non-damaging temperature at which the metal will creep and under a gas pressure of at least 7,500 psi for a period of time sufficient to substantially eliminate porosity, C. slicing the resultant non-porous ingot into sheets.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said pressure is exerted by argon gas.
Claim 4
Dependent Claim
22 words
The process of claim 1 wherein the ingot is maintained at temperature and pressure for a period of at least 1 hour.
Claim 5
Dependent Claim
68 words
A process for forming sheet material substantially free from surface imperfections comprising: A. casting an ingot comprising 9-10 percent silicon, 5.5-6.5 percent aluminum and the balance iron and residuals, B. maintaining the ingot at a non-damaging temperature of at least 1,750*F and a gas pressure of at least 7,500 psi for a period of time sufficient to substantially eliminate porosity, C. slicing the resultant non-porous ingot into sheets.
Claim 6
Dependent Claim
68 words
A process for forming sheet material substantially free from surface imperfections comprising: A. casting an ingot comprising 9-10 percent silicon, 5.5-6.5 percent aluminum and the balance iron and residuals, B. maintaining the ingot at a non-damaging temperature of at least 1,750*F and a gas pressure of at least 7,500 psi for a period of time sufficient to substantially eliminate porosity, C. slicing the resultant non-porous ingot into sheets.
Claim 7
Dependent Claim
12 words
The process of claim 2 wherein said temperature is at least 1,900*F.
Claim 8
Dependent Claim
14 words
The process of claim 2 wherein said pressure is at least 10, 000 psi.
References Cited (Backward Citations)
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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) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |