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US4545826A
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Method for producing a weldable austenitic stainless steel in heavy sections
Assignee: Allegheny Ludlum Corp
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Filing: 1984-06-29
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Granted: 1985-10-08
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Expires: 2004-06-29
Abstract
Abstract A method is provided for producing a nickel-chromium-molybdenum austenitic stainless steel in heavy section sizes and in welded article form substantially free of second phase precipitation from annealing and welding temperatures. The method includes providing nitrogen additions and annealing at temperatures of less than 2100 DEG F., preferably less than 2000 DEG F.
Inventors
- 👤 Thomas H. McCunn
- 👤 John P. Ziemianski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:07
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/44; C21; C21D; C21D6/00; C21D6/004; C21D8/00; C21D8/02; C22C38/001; C21D2211/00; C21D2211/001
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
87 words
A method for producing an austenitic stainless steel article in heavy sections, said steel comprises, by weight, 20 to 40% nickel, 14 to 21% chromium, 6 to 12% molybdenum, 0.15 to 0.30% nitrogen, and the remainder substantially all iron, the method comprising melting, casting, hot rolling and cold rolling the steel to final gauge greater than 0.065 inch, fully annealing the final gauge steel at temperatures of greater than 1900° F. and less than about 2100° F. to produce a steel substantially free of second phase precipitation.
Claim 2
Independent Claim
87 words
A method for producing an austenitic stainless steel article in heavy sections, said steel comprises, by weight, 20 to 40% nickel, 14 to 21% chromium, 6 to 12% molybdenum, 0.15 to 0.30% nitrogen, and the remainder substantially all iron, the method comprising melting, casting, hot rolling and cold rolling the steel to final gauge greater than 0.065 inch, fully annealing the final gauge steel at temperatures of greater than 1900° F. and less than about 2100° F. to produce a steel substantially free of second phase precipitation.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein the steel has nitrogen ranging from 0.18 to 0.25%.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein the steel includes up to 2% manganese.
Claim 5
Dependent Claim
26 words
The method of claim 1, wherein the steel includes 20 to 30% nickel, 18 to 21% chromium, 6 to 8% molybdenum, and 0.18 to 0.25% nitrogen.
Claim 6
Dependent Claim
35 words
The method of claim 1, wherein the steel comprises 20 to 40% nickel, 14 to 21% chromium, 6 to 12% molybdenum, 0.15 to 0.30% nitrogen, up to 2% manganese, and the remainder substantially all iron.
Claim 7
Dependent Claim
14 words
The method of claim 1, wherein the final gauge ranges up to 1.5 inches.
Claim 8
Dependent Claim
15 words
The method of claim 1, wherein the steel is annealed at less than 2000° F.
Claim 9
Dependent Claim
21 words
The method of claim 1, further including welding the steel to produce a welded article substantially free of second phase precipitation.
Claim 10
Dependent Claim
14 words
The method of claim 8, wherein welding includes using a nickel-base weld filler metal.
Claim 11
Dependent Claim
32 words
An article made by the method of claim 1 having a second phase solvus temperature reduced to below 2000° F. and a critical crevice corrosion temperature of about 85° F. or more.
Claim 12
Dependent Claim
18 words
A welded article made by the method of claim 8 and being substantially free of second phase precipitation.
Claim 13
Independent Claim
83 words
A method for producing an austenitic stainless steel article, said steel comprises, by weight, 20 to 40% nickel, 14 to 21% chromium, 6 to 12% molybdenum, 0.15 to 0.30% nitrogen, up to 2% manganese, and the remainder substantially all iron, the method comprising melting, casting, hot rolling and cold rolling the steel to final gauge greater than 0.065 inch, annealing the final gauge steel at temperatures of between about 1900 and 2000° F. to produce a steel substantially free of second phase precipitation.
Claim 14
Independent Claim
83 words
A method for producing an austenitic stainless steel article, said steel comprises, by weight, 20 to 40% nickel, 14 to 21% chromium, 6 to 12% molybdenum, 0.15 to 0.30% nitrogen, up to 2% manganese, and the remainder substantially all iron, the method comprising melting, casting, hot rolling and cold rolling the steel to final gauge greater than 0.065 inch, annealing the final gauge steel at temperatures of between about 1900 and 2000° F. to produce a steel substantially free of second phase precipitation.
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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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |