Patent US2567791A successfully refreshed from Google Patents.
US2567791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of heat-treating gray cast iron
Assignee: Huntington Alloys Corp
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Filing: 1949-08-10
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Granted: 1951-09-11
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Expires: 1969-08-10
Abstract
No abstract record available.
Inventors
- 👤 Frederick G Sefing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:01
CPC Classifications
C; C21; C21D; C21D6/00; C21D6/04; C21D5/00; C22; C22C; C22C37/00; C22C37/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
135 words
THE IMPROVED PROCESS FOR PRODUCING A HARD, WEAR-RESISTANT, CORROSION-RESISTANT ALLOY GRAY CAST IRON CASTING WHICH COMPRISES SUBJECTING AN ALLOY GRAY CAST IRON CASTING CONTAINING ABOUT 2.5% TO ABOUT 3% CARBON, ABOUT 7.5% TO ABOUT 9% NICKEL ABOUT 3.5% TO ABOUT 4% COPPER, ABOUT 2% TO ABOUT 2.5% CHROMIUM, ABOUT 1.75% TO 2.25% SILICON, AND THE BALANCE ESSENTIALLY IRON TO A THERMAL TREATMENT COMPRISING HEATING SAID CASTING TO A TEMPERATURE OF ABOUT 1600* F. TO ABOUT 1800* F., RAPIDLY COOLING SAID HEATED CASTING TO A TEMPERATURE BELOW ABOUT 900* F. TO SOFTEN SAID CASTING TO A MACHINABLE HARDNESS LEVEL OF ABOUT 180 TO ABOUT 250 BRINELL, AND THEREAFTER SUBJECTING SAID CASTING TO A HARDENING TREATMENT AT A TEMPERATURE BELOW ABOUT MINUS 70* F. TO HARDEN SAID CASTING TO A HARDNESS OF AT LEAST ABOUT 450 BRINELL.
Claim 2
Dependent Claim
135 words
THE IMPROVED PROCESS FOR PRODUCING A HARD, WEAR-RESISTANT, CORROSION-RESISTANT ALLOY GRAY CAST IRON CASTING WHICH COMPRISES SUBJECTING AN ALLOY GRAY CAST IRON CASTING CONTAINING ABOUT 2.5% TO ABOUT 3% CARBON, ABOUT 7.5% TO ABOUT 9% NICKEL ABOUT 3.5% TO ABOUT 4% COPPER, ABOUT 2% TO ABOUT 2.5% CHROMIUM, ABOUT 1.75% TO 2.25% SILICON, AND THE BALANCE ESSENTIALLY IRON TO A THERMAL TREATMENT COMPRISING HEATING SAID CASTING TO A TEMPERATURE OF ABOUT 1600* F. TO ABOUT 1800* F., RAPIDLY COOLING SAID HEATED CASTING TO A TEMPERATURE BELOW ABOUT 900* F. TO SOFTEN SAID CASTING TO A MACHINABLE HARDNESS LEVEL OF ABOUT 180 TO ABOUT 250 BRINELL, AND THEREAFTER SUBJECTING SAID CASTING TO A HARDENING TREATMENT AT A TEMPERATURE BELOW ABOUT MINUS 70* F. TO HARDEN SAID CASTING TO A HARDNESS OF AT LEAST ABOUT 450 BRINELL.
References Cited (Backward Citations)
US2530545A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-09-10 | 1955-03-12 | 1955-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-09-10 | 1959-03-12 | 1959-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-09-10 | 1963-03-12 | 1963-09-11 | $7700.00 | Window Closed / Lapsed |