US3963532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fe, Cr ferritic alloys containing Al and Nb
Assignee: EIDP Inc
•
Filing: 1974-05-30
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Granted: 1976-06-15
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Expires: 1994-05-30
Abstract
Abstract Ferritic iron-chromium alloys containing 25-28 wt. per cent chromium inhibited against the embrittling effects of C+N up to a combined total of about 0.18 weight per cent by inclusion of Nb together with Al.
Inventors
- 👤 Joseph J. Demo, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:57
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/26
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
157 words
A ferritic alloy having good as-welded ductility in that it passes the standard guided bend test prescribed by the A.S.M.E. Pressure Vessel Code, 1965, Section 9, Page 59 using a bend test jig having a bend radius to sample thickness ratio of 2 without visible cracking, and good corrosion resistance in that it passes the ASTM A-262-70, 1971 Book of Standards, Practice B test consisting of immersion in boiling 50% H 2 SO 4 containing 41.6 gm./liter of ferric sulfate as inhibitor in repeated cycles of 24 hours duration each up to a total exposure of 120 hours, after which the specimens tested exhibited a corrosion rate of less than 40 mils (10.16 × 10 - 2 cm) per year, consisting essentially of the following percentages by weight: chromium 25-28
molybdenum 0-1.5
aluminum 0.05-1.0
carbon + nitrogen
0.18 max.
niobium 2% max. but at least
11 times the C+N content, the balance being iron and incidental impurities.
Claim 2
Dependent Claim
157 words
A ferritic alloy having good as-welded ductility in that it passes the standard guided bend test prescribed by the A.S.M.E. Pressure Vessel Code, 1965, Section 9, Page 59 using a bend test jig having a bend radius to sample thickness ratio of 2 without visible cracking, and good corrosion resistance in that it passes the ASTM A-262-70, 1971 Book of Standards, Practice B test consisting of immersion in boiling 50% H 2 SO 4 containing 41.6 gm./liter of ferric sulfate as inhibitor in repeated cycles of 24 hours duration each up to a total exposure of 120 hours, after which the specimens tested exhibited a corrosion rate of less than 40 mils (10.16 × 10 - 2 cm) per year, consisting essentially of the following percentages by weight: chromium 25-28
molybdenum 0-1.5
aluminum 0.05-1.0
carbon + nitrogen
0.18 max.
niobium 2% max. but at least
11 times the C+N content, the balance being iron and incidental impurities.
Claim 3
Dependent Claim
51 words
A ferritic alloy having good as-welded ductility and corrosion resistance according to claim 1 consisting essentially of the following percentages by weight: chromium 26-27
molybdenum 0.5-1.5
aluminum 0.05-1.0
carbon + nitrogen
0.15 max.
niobium 2.0% max. but at least
11 times the C+N content, the balance being iron and incidental impurities.
Claim 4
Dependent Claim
51 words
A ferritic alloy having good as-welded ductility and corrosion resistance according to claim 1 consisting essentially of the following percentages by weight: chromium 26-27
molybdenum 0.5-1.5
aluminum 0.1-0.8
carbon + nitrogen
0.15 max.
niobium 2.0% max. but at least
11 times the C+N content, the balance being iron and incidental impurities.
Claim 5
Dependent Claim
10 words
A welded article fabricated from the alloy of claim 1.
References Cited (Backward Citations)
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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) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |