Patent US1113632A successfully refreshed from Google Patents.
US3929520A
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Corrosion-resistant austenitic-ferritic stainless steel
Assignee: NORSTROM LARS AKE
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Filing: 1974-08-30
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Granted: 1975-12-30
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Expires: 1994-08-30
Abstract
Abstract A corrosion resisting steel with considerably higher yield point and ultimate tensile strength as well as good ductility and impact strength is achieved by adding a comparatively large quantity (2-4% by weight) of Si to a high chromium austeniticferritic steel. The resultant steel typically has a composition (percent by weight):
Inventors
- 👤 Lars Ivar Hellner
- 👤 Lars-Ake Norstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:31
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/44
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
96 words
CORROSION-RESISTING AUSTENITICFERRITIC STAINLESS STEEL HAVING AN AUSTENITE CONTENT OF BETWEEN 10% AND 25% BY VOLUME AND A FERRITE CONTENT OF BETWEEN 90% AND 75% BY VOLUME, SAID STEEL HAVING HIGH STRENGTH, HIGH DUCTILITY AND IMPACT STRENGTH, HIGH GENERAL CORROSION RESISTANCE,HIGH RESISTANCE TO STRESS CORROSION IN CHLORIDE SOLUTIONS, AND HIGH RESISTANCE TO INTERGRANULAR CORROSION IN WARM CHLORIDE SOLUTIONS, SAID STEEL CONSISTING ESSENTIALLY OF (PERCENT BY WEIGHT): C MAX 0.15 SI 2.0 - 4.0 MN 0.5 - 3.0 CR 23 - 27 NI 3.5 - 8.0 MO 0.5 - 2.0 N MAX 0.1 AND THE BALANCE SUBSTANTIALLY IRON.
Claim 2
Dependent Claim
96 words
CORROSION-RESISTING AUSTENITICFERRITIC STAINLESS STEEL HAVING AN AUSTENITE CONTENT OF BETWEEN 10% AND 25% BY VOLUME AND A FERRITE CONTENT OF BETWEEN 90% AND 75% BY VOLUME, SAID STEEL HAVING HIGH STRENGTH, HIGH DUCTILITY AND IMPACT STRENGTH, HIGH GENERAL CORROSION RESISTANCE,HIGH RESISTANCE TO STRESS CORROSION IN CHLORIDE SOLUTIONS, AND HIGH RESISTANCE TO INTERGRANULAR CORROSION IN WARM CHLORIDE SOLUTIONS, SAID STEEL CONSISTING ESSENTIALLY OF (PERCENT BY WEIGHT): C MAX 0.15 SI 2.0 - 4.0 MN 0.5 - 3.0 CR 23 - 27 NI 3.5 - 8.0 MO 0.5 - 2.0 N MAX 0.1 AND THE BALANCE SUBSTANTIALLY IRON.
Claim 3
Dependent Claim
11 words
Steel according to claim 1, consisting essentially of (percent by weight):
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) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |