US4222771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High chromium steel of mixed structure containing ferrite for high temperature use
Assignee: Mitsubishi Heavy Industries Ltd
•
Filing: 1979-01-23
•
Granted: 1980-09-16
•
Expires: 1999-01-23
Abstract
Abstract High chromium steel, for use at high temperature, of a mixed structure containing ferrite and 0.02-0.09% C, less than 1.0% Si, 0.1-2.0% Mn, 7.0-13.0% chromium, 1.2-3.0% Mo, and the rest being iron and the usual impurities, or further adding aluminum in an amount less than 0.1% to said composition, or further adding 0.001-0.1% boron and less than 0.1% Ti necessary to cause the boron to act effectively, said steel being heated at temperatures lower than about 1050 DEG C. to prevent the oxidation of the steel.
Inventors
- 👤 Teishiro Oda
- 👤 Takashi Daikoku
- 👤 Teruo Yukitoshi
- 👤 Kazuhiko Nishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:32
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
59 words
A high chromium steel for use at high temperatures consisting essentially of: 0.02-0.09% carbon, less than 1.0% silicon, 0.1-2.0% manganese, 7.0-13.0% chromium, 1.2-3.0% molybdenum, said steel further consisting essentially of a mixed structure of ferrite and bainite, the ferrite phase being present in an amount from about 20 to 60% with the balance being iron and the usual impurities.
Claim 2
Dependent Claim
59 words
A high chromium steel for use at high temperatures consisting essentially of: 0.02-0.09% carbon, less than 1.0% silicon, 0.1-2.0% manganese, 7.0-13.0% chromium, 1.2-3.0% molybdenum, said steel further consisting essentially of a mixed structure of ferrite and bainite, the ferrite phase being present in an amount from about 20 to 60% with the balance being iron and the usual impurities.
Claim 3
Dependent Claim
65 words
A high chromium steel for use at high temperatures consisting essentially of the following elements: 0.02-0.09% carbon, less than 1.0% silicon, 0.1-2.0% manganese, 7.0-13.0% chromium, 1.2-3.0% molybdenum, less than 0.1% aluminum, said steel consisting essentially of a mixed structure of ferrite and bainite, the ferrite phase being present in an amount from about 20 to 60% with the balance being iron and the usual impurities.
Claim 4
Dependent Claim
65 words
A high chromium steel for use at high temperatures consisting essentially of the following elements: 0.02-0.09% carbon, less than 1.0% silicon, 0.1-2.0% manganese, 7.0-13.0% chromium, 1.2-3.0% molybdenum, less than 0.1% aluminum, said steel consisting essentially of a mixed structure of ferrite and bainite, the ferrite phase being present in an amount from about 20 to 60% with the balance being iron and the usual impurities.
References Cited (Backward Citations)
US2123144A
Cited
US2905577A
Cited
US2835571A
Cited
US3539338A
Cited
US3926685A
Cited
US3847600A
Cited
US3834897A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |