US3288657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Special heat treating method of steels
Assignee: Yawata Iron and Steel Co Ltd
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Filing: 1963-08-05
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Granted: 1966-11-29
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Expires: 1983-08-05
Abstract
No abstract record available.
Inventors
- 👤 Morita Sadayoshi
- 👤 Sato Makoto
- 👤 Furuya Mitsuo
- 👤 Yamaguchi Yoshinori
- 👤 Umeda Teruo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:04
CPC Classifications
C; C22; C22C; C22C38/00; C21; C21D; C21D1/00; C21D1/18; C21D8/00; C21D8/02; C21D9/00; C21D9/46; C22C38/04; C21D2211/00; C21D2211/005; C21D2211/009
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
140 words
A PROCESS FOR HEAT-TREATING CARBON STEEL CONSISTING OF AT LEAST 50% FERRITE AND PEARLITE, WHICH COMPRISES (1) HEATING SAID CARBON STEEL TO A TEMPERATURE BETWEEN THE AC3 TRANSFORMATION POINT AND 950*C. AND QUENCHING THE HEATED STEEL, (2) REHEATING THE MARDENED STEEL TO A TEMPERATURE BETWEEN THE TRANSFORMATION POINTS AC1 AND AC3, HOLDING IT AT THIS TEMPERATURE FOR A MAXIMUM OF 60 MINUTES PER INCH OF PLATE THICKNESS, AND THEN QUENCHING SAID STEEL, (3) REHEATING THE HARDENED STEEL TO A TEMPERATURE BETWEEN THE TRANSFORMATION POINTS AC1 AND AC3, HOLDING IT AT THIS TEMPERATURE FOR A MAXIMUM OF 60 MINUTES PER INCH OF PLATE THICKNESS, AND THEN QUENCHING SAID STEEL, AND (4) SUBJECTING THE TREATED STEEL TO A TEMPERING TREATMENT, IN WHICH THE SAID STEEL IS HEATED TO A TEMPERATURE BELOW THE AC1 TRANSFORMATION POINT, THEREBY OBTAINING CARBON STEEL HAVING GOOD NOTCH-TOUGHNESS.
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) | 1969-11-28 | 1970-05-30 | 1970-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-11-28 | 1974-05-30 | 1974-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-11-28 | 1978-05-30 | 1978-11-29 | $7700.00 | Window Closed / Lapsed |