US3859147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hot hard stainless steel
Assignee: Carpenter Technology Corp
•
Filing: 1974-02-11
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Granted: 1975-01-07
•
Expires: 1994-02-11
Abstract
Abstract A hot hard chromium stainless steel having good hot workability containing about 0.9-1.4% carbon, 13-19% chromium, 1.5-2.75% molybdenum, 0.3-2.5% vanadium, 0.10-0.55% columbium and the balance primarily iron.
Inventors
- 👤 Thoni V Philip
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:15
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/24; C22C38/22
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
83 words
A STAINLESS STEEL HAVING GOOD HOT WORKABILITY, WHICH IS HARDENED BY HEATING AT ABOUT 2100*F AND TEMPERED TO A ROOM TEMPERATURE HARDNESS OF AT LEAST ABOUT ROCKWELL C60 AND A HOT HARDNESS GREATER THAN ABOUT RC 50 AT 1000*F, AND WHICH IN ITS HEAT TREATED CONDITION IS SUBSTANTIALLY FREE OF RETAINED AUSTENITE, WHICH BY WEIGHT CONSISTS ESSENTIALLY OF ABOUT CARBON 0.9-1.4% MANGANESE 1% MAXIMUM SILCON 1% MAXIMUM CHROMIUM 13-19% MOLBDENUM 1.5-2.75% VANADIUM 0.3-2.5% COLUMBIUM 0.10-0.55% THE BALANCE BEING ESSENTIALLY IRON AND INCIDENTAL IMPURITIES.
Claim 2
Dependent Claim
83 words
A STAINLESS STEEL HAVING GOOD HOT WORKABILITY, WHICH IS HARDENED BY HEATING AT ABOUT 2100*F AND TEMPERED TO A ROOM TEMPERATURE HARDNESS OF AT LEAST ABOUT ROCKWELL C60 AND A HOT HARDNESS GREATER THAN ABOUT RC 50 AT 1000*F, AND WHICH IN ITS HEAT TREATED CONDITION IS SUBSTANTIALLY FREE OF RETAINED AUSTENITE, WHICH BY WEIGHT CONSISTS ESSENTIALLY OF ABOUT CARBON 0.9-1.4% MANGANESE 1% MAXIMUM SILCON 1% MAXIMUM CHROMIUM 13-19% MOLBDENUM 1.5-2.75% VANADIUM 0.3-2.5% COLUMBIUM 0.10-0.55% THE BALANCE BEING ESSENTIALLY IRON AND INCIDENTAL IMPURITIES.
Claim 3
Dependent Claim
13 words
The stainless steel set forth in claim 1 which contains about 0.95-1.15% carbon.
Claim 4
Dependent Claim
13 words
The stainless steel set forth in claim 2 which contains about 13.5-14.5% chromium.
Claim 5
Dependent Claim
13 words
The stainless steel set forth in claim 3 which contains about 1.75-2.5% molybdenum.
Claim 6
Dependent Claim
13 words
The stainless steel set forth in claim 4 which contains about 0.75-1.25% vanadium.
Claim 7
Dependent Claim
13 words
The stainless steel set forth in claim 5 which contains about 0.20-0.35% columbium.
Claim 8
Dependent Claim
16 words
The stainless steel set forth in claim 6 which contains less than about 1% retained austenite.
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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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |