Ferritic heat-resistant steel
Abstract
Abstract A HEAT-RESISTANT FERRITIC STEEL CONTAINS FROM 10% TO 15% CHROMIUM, THE LATTER''S EFFECT IN MAKING THE STEEL RESISTANT TO OXIDATION BEING HELPED BY SMALL AMOUNTS OF ALUMINUM, SILICON, AND TO SOME EXTENT BY TITANIUM, THE LATTER, POSSIBLY ASSISTEDD BY OTHER STRONG CARBIDE-FORMERS, ALSO PREVENTING CHROMIUM LOSS AT THE STEEL''S GRAIN BOUNDARIES, THE STEEL ADDITIONALLY CONTAINING SMALL BUT EFFECTIVE AMOUNTS OF CALCIUM, CERIUM OR OTHER RARE EARTH METALS USED SINGLY OR TOGETHER AND CAUSING ANY SCALE THAT FORMS TO BE ADHERENT AND FREE FROM FLAKING. THE STEEL IS PARTICULARLY ADAPTED FOR ELEVATED TEMPERATURE USE UNDER OXIDIZING CONDITIONS, PARTICULARLY WHEN THE SERVICE INVOLVES THERMAL SHOCK CONDITIONS, EXEMPLIFIED BY THE OPERATION OF INTERNAL COMBUSTION EXHAUST AFTER-BURNERS OR CATALYTIC REACTORS REQUIRED FOR POLLUTION CONTROL.
Inventors
- 👤 H Brandis
- 👤 R Oppenheim
Bibliographic Details
Claims Analysis
Total Claims: 0References 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) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |