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US3947266A Expired / Lapsed US ⏱️ 0.0 years remaining

Corrosion-resistant alloys

Assignee: Carondelet Foundry Co
•
Filing: 1974-05-17
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Granted: 1976-03-30
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Expires: 1994-05-17
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Abstract

Abstract An air-meltable, castable, workable alloy resistant to corrosion in sulfuric acid over a wide range of acid strengths. The alloy consists essentially of between about 28.59 and about 36.72% by weight nickel, between about 26.33 and about 30.15% by weight chromium, between about 3 and about 4.1% by weight molybdenum, between about 3 and about 4.5% by weight copper, between about 3 and about 4% by weight manganese, up to about 0.5% by weight cobalt, up to about 0.60% by weight silicon, up to about 0.07% by weight carbon, up to about 1% by weight tantalum, up to about 1% by weight titanium, up to about 2.38% by weight niobium, up to about 0.010% by weight boron, up to about 0.6% by weight of a rare earth component selected from the group consisting of cerium, lanthanum and misch metal, up to about 0.15% by weight nitrogen, and the balance essentially iron. The sum of the chromium content and 0.56 times the niobium content is between about 27 and about 31% by weight. The nickel content exceeds the chromium content by at least about 1.5% and also exceeds the sum of the chromium content and 0.56 times the niobium content by at least about 1.4%. Where the carbon content exceeds 0.04% by weight, it must be less than the sum of five times the titanium content and 10 times the niobium plus tantalum content.

Inventors

  • 👤 John H. Culling

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 00:29
CPC Classifications
C; C22; C22C; C22C30/00

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 238 words
An air-meltable, castable, workable alloy resistant to corrosion in sulfuric acid over a wide range of acid strengths consisting essentially of between about 28.59 and about 36.72% by weight nickel, between about 26.33 and about 30.15% by weight chromium, between about 3 and about 4.1% by weight molybdenum, between about 3 and about 4.5% by weight copper, between about 3 and about 4% by weight manganese, up to about 0.5% by weight cobalt, up to about 0.60% by weight silicon, up to about 0.07% by weight carbon, up to about 1% by weight tantalum, up to about 1% by weight titanium, up to about 2.38% by weight niobium, up to about 0.010% by weight boron, up to about 0.6% by weight of a rare earth component selected from the group consisting of cerium, lanthanum and misch metal, up to about 0.15% by weight nitrogen, and the balance essentially iron, provided that: a. the sum of the chromium content and 0.56 times the niobium content is between about 27 and about 31% by weight; b. the nickel content exceeds the chromium content by at least about 1.5%; c. the nickel content exceeds the sum of the chromium content and 0.56 times the niobium content by at least about 1.4%; and d. where the carbon content exceeds 0.04% by weight, it is less than the sum of five times the titanium content and 10 times the niobium plus tantalum content.
Claim 2
Dependent Claim 238 words
An air-meltable, castable, workable alloy resistant to corrosion in sulfuric acid over a wide range of acid strengths consisting essentially of between about 28.59 and about 36.72% by weight nickel, between about 26.33 and about 30.15% by weight chromium, between about 3 and about 4.1% by weight molybdenum, between about 3 and about 4.5% by weight copper, between about 3 and about 4% by weight manganese, up to about 0.5% by weight cobalt, up to about 0.60% by weight silicon, up to about 0.07% by weight carbon, up to about 1% by weight tantalum, up to about 1% by weight titanium, up to about 2.38% by weight niobium, up to about 0.010% by weight boron, up to about 0.6% by weight of a rare earth component selected from the group consisting of cerium, lanthanum and misch metal, up to about 0.15% by weight nitrogen, and the balance essentially iron, provided that: a. the sum of the chromium content and 0.56 times the niobium content is between about 27 and about 31% by weight; b. the nickel content exceeds the chromium content by at least about 1.5%; c. the nickel content exceeds the sum of the chromium content and 0.56 times the niobium content by at least about 1.4%; and d. where the carbon content exceeds 0.04% by weight, it is less than the sum of five times the titanium content and 10 times the niobium plus tantalum content.
Claim 3
Dependent Claim 31 words
An alloy as set forth in claim 1 wherein the chromium content is at least about 27% by weight and the copper content is no greater than about 4% by weight.
Claim 4
Dependent Claim 34 words
An alloy as set forth in claim 2 wherein the nickel content is on the order of 4% by weight greater than the sum of the chromium content and 0.56 times the niobium content.
Claim 5
Dependent Claim 42 words
An alloy as set forth in claim 3 wherein the nickel content is between about 31 and about 32% by weight and the sum of chromium content and 0.56 times the niobium content is between about 27 and about 28% by weight.
Claim 6
Dependent Claim 18 words
An alloy as set forth in claim 1 wherein the silicon content is not substantially greater than 0.45%.

References Cited (Backward Citations)

US3044871A Cited
US3552950A Cited
US3582318A Cited
US3758294A Cited
US3758296A Cited
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US3813239A Cited
US3844774A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-03-30 1979-09-29 1980-03-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-03-30 1983-09-29 1984-03-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-03-30 1987-09-29 1988-03-30 $7700.00 Window Closed / Lapsed

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