Patent US3926620A successfully refreshed from Google Patents.
US3926620A
Expired / Lapsed
US
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Low carbon ni-cr alloy steel having an improved resistance to stress corrosion cracking
Assignee: Nippon Steel Corp
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Filing: 1974-02-07
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Granted: 1975-12-16
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Expires: 1994-02-07
Abstract
Abstract Herein disclosed is a low-carbon Ni-Cr alloy steel being substantially in the single phase of austenite and improved in resistance to stress corrosion cracking. The alloy steel consists essentially of, by weight, less than 0.03% of carbon, 1.5 to 4.0% of silicon, 0.1 to 3.0% of manganese, 25 to 45% of nickel, 24 to 35% of chromium, 0.9 to 4.0% of vanadium and, if desired, copper and/or molybdenum in a total amount of 0.3 to 4.0%, and the balance of iron. This alloy steel has outstanding utility as a structural material of heat exchanger, mainly for use in the nuclear reactor.
Inventors
- 👤 Masamichi Kowaka
- 👤 Hisao Fujikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:17
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/46; C22C19/00; C22C19/03; C22C19/05; C22C19/058
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
62 words
A LOW CARBON NI-CR ALLOY STEEL BEING SUBSTANTIALLY IN THE SINGLE PHASE OF AUSTENITE AND IMPROVED IN RESISTANCE TO STRESS CORROSION CRACKING CONSISTING ESSENTIALLY OF, BY WEIGHT, LESS THAN 0.03% OF CARBON, 1.5 TO 4.0% SILICON, 0.1 TO 3.0% OF MANGANESE, 25 TO 45% OF NICKEL, 24 TO 35% OF CHROMIUM, 0.9 TO 4.0% OF VANADIUM AND THE BALANCE ESSENTIALLY OF IRON.
Claim 2
Dependent Claim
62 words
A LOW CARBON NI-CR ALLOY STEEL BEING SUBSTANTIALLY IN THE SINGLE PHASE OF AUSTENITE AND IMPROVED IN RESISTANCE TO STRESS CORROSION CRACKING CONSISTING ESSENTIALLY OF, BY WEIGHT, LESS THAN 0.03% OF CARBON, 1.5 TO 4.0% SILICON, 0.1 TO 3.0% OF MANGANESE, 25 TO 45% OF NICKEL, 24 TO 35% OF CHROMIUM, 0.9 TO 4.0% OF VANADIUM AND THE BALANCE ESSENTIALLY OF IRON.
Claim 3
Dependent Claim
84 words
A low carbon Ni-Cr alloy steel being substantially in the single phase of austenite and improved in resistance to stress corrosion cracking, consisting essentially of, by weight, less than 0.03% of carbon, 1.5 to 4.0% of silicon, 0.1 to 3.0% of manganese, 25 to 45% of nickel, 24 to 35% of chromium, 0.9 to 4.0% of vanadium and at least one selected from the group consisting of copper and molybdenum in a total amount of 0.3 to 4.0%, and the balance essentially of iron.
Claim 4
Dependent Claim
84 words
A low carbon Ni-Cr alloy steel being substantially in the single phase of austenite and improved in resistance to stress corrosion cracking, consisting essentially of, by weight, less than 0.03% of carbon, 1.5 to 4.0% of silicon, 0.1 to 3.0% of manganese, 25 to 45% of nickel, 24 to 35% of chromium, 0.9 to 4.0% of vanadium and at least one selected from the group consisting of copper and molybdenum in a total amount of 0.3 to 4.0%, and the balance essentially of iron.
Claim 5
Dependent Claim
21 words
An alloy according to claim 1 comprising at least one of copper and molybdenum, the total amount being up to 4%.
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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |