US3314831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat treatment for precipitationhardening steels
Assignee: North American Aviation Corp
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Filing: 1961-10-26
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Granted: 1967-04-18
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Expires: 1981-10-26
Abstract
No abstract record available.
Inventors
- 👤 Arthur F Hoenie
- 👤 Richard M Potter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:01
CPC Classifications
C; C21; C21D; C21D6/00; C21D6/004
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
170 words
A METHOD OF HEAT TREATING PRECIPITATION-HARDENING STEEL CONTAINING FROM ABOUT 0.03% TO ABOUT 0.15% CARBON, FROM ABOUT 12.0% TO ABOUT 18.0% CHROMIUM, AND FROM ABOUT 3.5% TO ABOUT 7.0% NICKEL PRIOR TO PROCESS ANNEAL, TRANSFORMATION, AND AGING OPERATIONS, AND WHICH COMPRISES THE STEPS OF: (A) ANNEALING SAID STEEL AT A TEMPERATURE WHICH IS ABOVE THE MINIMUM SOLUTIONING TEMPERATURE OF SAID STEEL TO DISSOLVE METAL CARBIDES WITHIN AN AUSTENITE PHASE OF SAID STEEL AND THEN RAPIDLY COOLING SAID STEEL TO AMBIENT TEMPERATURE, (B) STABILIZING SAID STEEL AT A TEMPERATURE WHICH IS IN THE RANGE OF APPROXIMATELY 1500*F. TO APPROXIMATELY 1625*F. TO DISPERSE THE CARBON AND CARBIDE CONSTITUENTS OF SAID STEEL UNIFORMLY IN SAID STEEL AUSTENITE PHASE. (C) AND THEN RAPIDLY COOLING SAID STEEL AMBIENT TEMPERATURE TO PRECIPITATE SAID CARBON AND CARBIDE CONSTITUENTS WITHIN SAID STEEL, AUSTENITE PHASE IN UNIFORMLY DISPERSED MANNER, AND (D) SUB-COOLING SAID STEEL AT A TEMPERATURE WHICH TRANSFORMS A SUBSTANTIAL PORTION OF SAID STEEL AUSTENITE PHASE TO MARTENSITE, SAID STABILIZING STEP INCREASING THE TRANSVERSE DUCTILITY OF SAID STEEL.
Claim 2
Independent Claim
170 words
A METHOD OF HEAT TREATING PRECIPITATION-HARDENING STEEL CONTAINING FROM ABOUT 0.03% TO ABOUT 0.15% CARBON, FROM ABOUT 12.0% TO ABOUT 18.0% CHROMIUM, AND FROM ABOUT 3.5% TO ABOUT 7.0% NICKEL PRIOR TO PROCESS ANNEAL, TRANSFORMATION, AND AGING OPERATIONS, AND WHICH COMPRISES THE STEPS OF: (A) ANNEALING SAID STEEL AT A TEMPERATURE WHICH IS ABOVE THE MINIMUM SOLUTIONING TEMPERATURE OF SAID STEEL TO DISSOLVE METAL CARBIDES WITHIN AN AUSTENITE PHASE OF SAID STEEL AND THEN RAPIDLY COOLING SAID STEEL TO AMBIENT TEMPERATURE, (B) STABILIZING SAID STEEL AT A TEMPERATURE WHICH IS IN THE RANGE OF APPROXIMATELY 1500*F. TO APPROXIMATELY 1625*F. TO DISPERSE THE CARBON AND CARBIDE CONSTITUENTS OF SAID STEEL UNIFORMLY IN SAID STEEL AUSTENITE PHASE. (C) AND THEN RAPIDLY COOLING SAID STEEL AMBIENT TEMPERATURE TO PRECIPITATE SAID CARBON AND CARBIDE CONSTITUENTS WITHIN SAID STEEL, AUSTENITE PHASE IN UNIFORMLY DISPERSED MANNER, AND (D) SUB-COOLING SAID STEEL AT A TEMPERATURE WHICH TRANSFORMS A SUBSTANTIAL PORTION OF SAID STEEL AUSTENITE PHASE TO MARTENSITE, SAID STABILIZING STEP INCREASING THE TRANSVERSE DUCTILITY OF SAID STEEL.
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) | 1970-04-17 | 1970-10-17 | 1971-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-04-17 | 1974-10-17 | 1975-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-04-17 | 1978-10-17 | 1979-04-18 | $7700.00 | Window Closed / Lapsed |