Patent US3694271A successfully refreshed from Google Patents.
US3694271A
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Method of producing articles of composite material,and resulting products
Assignee: Sandvik AB
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Filing: 1971-06-11
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Granted: 1972-09-26
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Expires: 1991-06-11
Abstract
Abstract A DUPLEX METAL ARTICLE, FOR HIGH-TEMPERATURE USE, CONSISTING OF A HIGH-STRENGHT AUSTENTIC STAINLESS STEEL AND A LAYER OF FERRITIC STAINLESS STEEL HAVING HIGH RESISTANCE TO STRESS CORROSION IS PRODUCED BY THE STEPS OF FORMING A COMPOSITE BILLET OF THE TWO METALS, HEAT-TREATING THE BILLET IN THE WAY NORMAL FOR AUSTENITIC STEEL, COLD-WORKING THE BILLET, AND HEAT-TREATING THE RESULTING ARTICLE AT SUCH A TEMPERATURE THAT ONLY THE FERRITIC STEEL IS RE-CRYSTALLIZED.
Inventors
- 👤 Lennart Oskar Egnell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:48
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/01; B32B15/011; B23; B23K; B23K20/00; B23K20/22; B23K20/227; B23K35/00; B23K35/02; B23K35/0255; B23K35/22; B23K35/24; B23K35/30; B23K35/3053; C; C21; C21D; C21D8/00; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/54; F; F28; F28F; F28F21/00; F28F21/08; F28F21/081; F28F21/082; F28F21/083; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12951; Y10T428/12958; Y10T428/12965
Claims Analysis
Total Claims: 0
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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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |