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US4201575A Expired / Lapsed US ⏱️ 0.0 years remaining

Austenitic stainless corrosion-resistant alloy

Assignee: CRS Holdings LLC
•
Filing: 1979-05-18
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Granted: 1980-05-06
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Expires: 1999-05-18
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Abstract

Abstract An austenitic stainless corrosion resistant alloy consisting essentially in weight percent (w/o) of ______________________________________ Broad-(w/o) Preferred-(w/o) ______________________________________ C 0.06 Max. 0.015-0.025 Mn 1.00 Max. 0.50 Max. Si 0.50 Max. 0.40 Max. P 0.03 Max. 0.03 Max. S 0.03 Max. 0.005 Max. Cr 22-26 23.5-24.5 Ni 32.5-37 32.5-34.5 Mo 5-6.7 5.5-6.2 Cu 1.0-4 3.0-3.5 B 0.005 Max. 0.0015-0.0035 Nb 1 Max. 0.15-0.25 N 0.4 Max.* 0.05 Max. Ce + La 0.4 Max.** 0.3 Max.** ______________________________________ *OR the limit of solubility. **Amount added as misch metal. The balance is iron and incidental impurities. The alloy is useful for the production of parts requiring good resistance to corrosion. It has good resistance to pitting and stress corrosion when exposed to chlorides and has good resistance to oxidizing media. The alloy is particularly useful as parts for fume scrubbers and in phosphoric acid plants.

Inventors

  • 👤 Michael Henthorne
  • 👤 Terry DeBold

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 03:44
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/48; C22C38/44

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 105 words
An austenitic stainless corrosion resistant alloy having good resistance to pitting and crevice corrosion in chloride bearing media combined with resistance to corrosion in oxidizing media consisting essentially in weight percent of about ______________________________________ C 0.06 Max. Mn 1.00 Max. Si 0.50 Max. P 0.03 Max. S 0.03 Max. Cr 22-26 Ni 32.5-37 Mo 5-6.7 Cu 1.0-4 B 0.005 Max. Nb 1 Max. N 0.4 Max. Ce + La 0.4 Max. ______________________________________ the amount of nitrogen being not greater than that which can be retained in solution, the amount of cerium plus lanthanum being the amount added as misch metal, and the balance essentially iron.
Claim 2
Dependent Claim 105 words
An austenitic stainless corrosion resistant alloy having good resistance to pitting and crevice corrosion in chloride bearing media combined with resistance to corrosion in oxidizing media consisting essentially in weight percent of about ______________________________________ C 0.06 Max. Mn 1.00 Max. Si 0.50 Max. P 0.03 Max. S 0.03 Max. Cr 22-26 Ni 32.5-37 Mo 5-6.7 Cu 1.0-4 B 0.005 Max. Nb 1 Max. N 0.4 Max. Ce + La 0.4 Max. ______________________________________ the amount of nitrogen being not greater than that which can be retained in solution, the amount of cerium plus lanthanum being the amount added as misch metal, and the balance essentially iron.
Claim 3
Dependent Claim 22 words
The alloy set forth in claim 1 which contains a maximum of 0.03 w/o carbon, and a maximum of 0.35 w/o niobium.
Claim 4
Dependent Claim 17 words
The alloy set forth in claim 1 which contains about 0.015-0.025 w/o carbon and 0.15-0.25 w/o niobium.
Claim 5
Dependent Claim 13 words
The alloy set forth in claim 1 which contains about 3.0-3.5 w/o copper.
Claim 6
Dependent Claim 19 words
The alloy set forth in claim 1 which contains 0.001-0.0035 w/o boron, and no more than 0.05 w/o nitrogen.
Claim 7
Dependent Claim 19 words
The alloy set forth in claims 1, 2, 3, 4, or 5 which contains at least 5.2 w/o molybdenum.
Claim 8
Dependent Claim 20 words
The alloy set forth in claim 2 which contains more than 24 w/o chromium, and more than 6 w/o molybdenum.
Claim 9
Dependent Claim 24 words
The alloy set forth in claims 2 or 3 which contains no more than 23.5 w/o chromium, and no more than 5.5 w/o molybdenum.
Claim 10
Dependent Claim 17 words
The alloy set forth in claim 1 which contains about 23.5-24.5 w/o chromium, and 5.5-6.2 w/o molybdenum.
Claim 11
Dependent Claim 18 words
The alloy set forth in claim 3 which contains about 23.5-24.5 w/o chromium, and about 5.5-6.2 w/o molybdenum.
Claim 12
Dependent Claim 20 words
The alloy set forth in claims 9 or 10 which contains about 32.5-34.5 w/o nickel, and about 3.0-3.5 w/o copper.
Claim 13
Dependent Claim 26 words
The alloy set forth in claims 9 or 10 which contains no more than about 0.0035 w/o boron and no more than about 0.05 w/o nitrogen.
Claim 14
Dependent Claim 15 words
The alloy set forth in claim 12 which contains at least about 0.0015 w/o boron.
Claim 15
Dependent Claim 31 words
The alloy set forth in claim 12 which contains no more than about 0.50 w/o manganese, no more than about 0.40 w/o silicon, and no more than about 0.03 w/o phosphorus.
Claim 16
Dependent Claim 16 words
The alloy set forth in claim 14 which contains no more than about 0.005 w/o sulfur.
Claim 17
Dependent Claim 16 words
The alloy set forth in claim 6 which contains no more than about 0.005 w/o sulfur.
Claim 18
Dependent Claim 18 words
The alloy set forth in claims 9 or 10 which contains no more than about 0.005 w/o sulfur.
Claim 19
Dependent Claim 132 words
A corrosion resistant austenitic stainless article having good resistance to pitting and crevice corrosion in chloride bearing media combined with resistance to corrosion in oxidizing media and having the composition of an austenitic stainless alloy which in weight percent consists essentially of about ______________________________________ C 0.06 Max. Mn 1.00 Max. Si 0.50 Max. P 0.03 Max. S 0.03 Max. Cr 22-26 Ni 32.5-37 Mo 5-6.7 Cu 1.0-4 B 0.005 Max. Nb 1 Max. N 0.4 Max. Ce + La 0.4 Max. ______________________________________ the amount of nitrogen being not greater than that which can be retained in solution, the amount of cerium plus lanthanum being the amount added as misch metal, the balance essentially iron, and annealed at a temperature high enough above 955 C to minimize the formation of harmful secondary phases.
Claim 20
Dependent Claim 132 words
A corrosion resistant austenitic stainless article having good resistance to pitting and crevice corrosion in chloride bearing media combined with resistance to corrosion in oxidizing media and having the composition of an austenitic stainless alloy which in weight percent consists essentially of about ______________________________________ C 0.06 Max. Mn 1.00 Max. Si 0.50 Max. P 0.03 Max. S 0.03 Max. Cr 22-26 Ni 32.5-37 Mo 5-6.7 Cu 1.0-4 B 0.005 Max. Nb 1 Max. N 0.4 Max. Ce + La 0.4 Max. ______________________________________ the amount of nitrogen being not greater than that which can be retained in solution, the amount of cerium plus lanthanum being the amount added as misch metal, the balance essentially iron, and annealed at a temperature high enough above 955 C to minimize the formation of harmful secondary phases.
Claim 21
Dependent Claim 54 words
The article set forth in claim 18 in wrought form which consists essentially in weight percent of about ______________________________________ C 0.015-0.025 Mn 0.50 Max. Si 0.40 Max. P 0.03 Max. S 0.005 Max. Cr 23.5-24.5 Ni 32.5-34.5 Mo 5.5-6.2 Cu 3.0-3.5 B 0.0015-0.0035 Nb .15-0.25 N 0.05 Max. Ce + La 0.3 Max. ______________________________________

References Cited (Backward Citations)

US2777766A Cited
US3168397A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-05-06 1983-11-05 1984-05-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-05-06 1987-11-05 1988-05-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-05-06 1991-11-05 1992-05-06 $7700.00 Window Closed / Lapsed

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