US4383853A
Expired / Lapsed
US
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Corrosion-resistant Fe-Cr-uranium238 pellet and method for making the same
Assignee: MCCOLLOUGH WILLIAM J
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Filing: 1981-02-18
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Granted: 1983-05-17
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Expires: 2001-02-18
Abstract
Abstract High density, generally microscopically homogeneous corrosion-resistant chromium-uranium metal alloys for ammunition use (particularly for spherical pellets or shot) can be made from U 238 or an isotopic mixture high in U 238 (such as "depleted uranium") and at least about 10 atomic % chromium. The alloys can also contain one or more metals of Group VIII, first triad, of the Periodic Table, and a variety of other elements used, for example, in making ferrous metals. Major factors to be considered in formulating the alloy are density, melting point or melting range, passivity or chemical or biological inertness, resistance to segregation in the molten phase and upon rapid cooling (chromium-poor phases or regions being particularly undesirable), and compensation for any loss of free chromium due to formation of intermetallic or other forms of combined chromium. The uranium content in the alloy is preferably less than 70 atomic %. Rapid cooling of the chromium-uranium or chromium-uranium-Group VIII metal melt, e.g. by the shot tower technique, avoids undesirable segregation effects which can detract from corrosion resistance. The shot tower may optionally contain a non-oxidizing atmosphere.
Inventors
- 👤 Carl A. Zapffe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:35
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0257; C22C33/0278; C22C43/00; F; F42; F42B; F42B7/00; F42B7/02; F42B7/04; F42B7/046
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
107 words
A solid, generally spherical, generally corrosion-resistant, iron-chromium-uranium metal pellet consisting essentially of a generally corrosion-resistant iron-chromium-uranium alloy which has been cooled from the molten state to below its solidification temperature quickly enough to prevent the formation of any segregated uranium-rich phase containing less than 10 atomic percent chromium, thereby forming a fine-grain alloy structure, said iron-chromium-uranium alloy having a specific gravity of at least about 8.4 and consisting essentially of about 3 to about 35 atomic-% uranium, about 10 to 35 atomic-% chromium the major amount of the alloy, by atomic-%, being iron, the uranium of said iron-chromium-uranium containing more than 99.3% of the U 238 isotope.
Claim 2
Dependent Claim
107 words
A solid, generally spherical, generally corrosion-resistant, iron-chromium-uranium metal pellet consisting essentially of a generally corrosion-resistant iron-chromium-uranium alloy which has been cooled from the molten state to below its solidification temperature quickly enough to prevent the formation of any segregated uranium-rich phase containing less than 10 atomic percent chromium, thereby forming a fine-grain alloy structure, said iron-chromium-uranium alloy having a specific gravity of at least about 8.4 and consisting essentially of about 3 to about 35 atomic-% uranium, about 10 to 35 atomic-% chromium the major amount of the alloy, by atomic-%, being iron, the uranium of said iron-chromium-uranium containing more than 99.3% of the U 238 isotope.
Claim 3
Dependent Claim
31 words
A pellet according to claim 1 wherein the iron-chromium-uranium alloy contains an amount of chromium sufficient to make said alloy resistant to corrosion in moisture-containing environments at normal ambient outdoor temperatures.
Claim 4
Dependent Claim
18 words
A pellet according to claim 1 wherein the amount of chromium is at least about 12 atomic percent.
Claim 5
Dependent Claim
43 words
A pellet according to claim 1 consisting essentially of an iron-chromium-uranium alloy in which the iron content is less than 87 atomic-%, said iron-chromium-uranium alloy having been cooled from the molten state to a temperature approaching ambient in less than about one minute.
Claim 6
Dependent Claim
94 words
A solid, generally spherical metal shotgun pellet consisting essentially of a solid iron-chromium-uranium alloy having a specific gravity of at least about 8.4, said pellet having been formed by cooling to ambient temperature, in less than about a minute, a molten solution comprising a uranium isotope mixture in molten stainless steel, said isotope mixture containing more than 99.3% U 238 ; said solid alloy consisting essentially of about 3 to about 35 atomic % solid uranium, having essentially the isotopic distribution in said molten solution, about 50-87 atomic-% iron, and about 10-35 atomic-% chromium.
Claim 7
Dependent Claim
94 words
A solid, generally spherical metal shotgun pellet consisting essentially of a solid iron-chromium-uranium alloy having a specific gravity of at least about 8.4, said pellet having been formed by cooling to ambient temperature, in less than about a minute, a molten solution comprising a uranium isotope mixture in molten stainless steel, said isotope mixture containing more than 99.3% U 238 ; said solid alloy consisting essentially of about 3 to about 35 atomic % solid uranium, having essentially the isotopic distribution in said molten solution, about 50-87 atomic-% iron, and about 10-35 atomic-% chromium.
Claim 8
Dependent Claim
18 words
A pellet according to claim 5 wherein said uranium isotope mixture contains less than 0.3% U 235 .
Claim 9
Dependent Claim
113 words
In a process for making high density ammunition from uranium containing at least the naturally-occurring amount of the U 238 isotope, the steps comprising: (a) blending together, as elements or intermetallic compounds, the elements consisting essentially of about 3 to about 35 atomic % uranium, about 10-35 atomic % molten chromium, and about 50-87 atomic-% iron, in the molten state, thereby obtaining essentially a solution, (b) cooling the resulting solution to about ambient temperature quickly enough to prevent the formation of a segregated uranium-rich phase containing less than 10 atomic % free chromium, thereby obtaining a solid metal pellet having a fine grain structure and a specific gravity of at least about 8.4.
Claim 10
Dependent Claim
113 words
In a process for making high density ammunition from uranium containing at least the naturally-occurring amount of the U 238 isotope, the steps comprising: (a) blending together, as elements or intermetallic compounds, the elements consisting essentially of about 3 to about 35 atomic % uranium, about 10-35 atomic % molten chromium, and about 50-87 atomic-% iron, in the molten state, thereby obtaining essentially a solution, (b) cooling the resulting solution to about ambient temperature quickly enough to prevent the formation of a segregated uranium-rich phase containing less than 10 atomic % free chromium, thereby obtaining a solid metal pellet having a fine grain structure and a specific gravity of at least about 8.4.
Claim 11
Dependent Claim
42 words
A method according to claim 7 wherein the blend produced according to said step (a) is formed into molten drops which are exposed to normal ambient temperatures, thereby cooling the drops to solid, generally spheroidal pellets in less than about one minute.
Claim 12
Dependent Claim
28 words
A method according to claim 7 wherein at least part of the chromium and at least part of the iron are added as an iron-chromium alloy or mixture.
Claim 13
Dependent Claim
44 words
A method according to claim 9 wherein the iron-chromium mixture or alloy is (a) ferro-chromium obtained from reduced chromium oxide-containing ore, (b) scrap stainless steel, or (c) mixtures of (a) or (b) with a metal of Group VIII, first triad, of the Periodic Table.
Claim 14
Dependent Claim
66 words
An iron-chromium-uranium alloy having stainless properties and a specific gravity of at least about 8.4, said alloy consisting essentially of a fine-grain structure consisting essentially of: 3-35 atomic-% uranium, which uranium has at least the naturally-occurring amount of the U 238 isotope, 50-87 atomic-% iron, and 1- 35atomic-% chromium, said alloy being substantially free of solid segregated phases locally containing less than 10 atomic-% free chromium.
Claim 15
Dependent Claim
66 words
An iron-chromium-uranium alloy having stainless properties and a specific gravity of at least about 8.4, said alloy consisting essentially of a fine-grain structure consisting essentially of: 3-35 atomic-% uranium, which uranium has at least the naturally-occurring amount of the U 238 isotope, 50-87 atomic-% iron, and 1- 35atomic-% chromium, said alloy being substantially free of solid segregated phases locally containing less than 10 atomic-% free chromium.
Claim 16
Dependent Claim
32 words
An iron-chromium-uranium alloy according to claim 11 consisting essentially of: 15-35 atomic-% uranium 50-73 atomic-% iron, and 12-20 atomic-% chromium, said alloy having a melting point below the melting point of iron.
Claim 17
Dependent Claim
64 words
An iron-chromium-uranium alloy according to claim 11 containing 0-5 atomic-% of a combination of other metals or nonmetals typically found in stainless steel, said metals or nonmetals being selected from silicon; a Group VIII element, other than iron; carbon; manganese; molybdenum; aluminum; copper; vanadium; wolfram; zirconium; boron; tantalum; or niobium; and further containing up to trace amounts of nitrogen, selenium, phosphorus, hydrogen or oxygen.
Claim 18
Dependent Claim
38 words
A shotgun pellet according to claim 5 wherein said pellet is about 1-10 mm in diameter and said alloy consists essentially of a fine-grain structure consisting essentially of: 15-35 atomic-% uranium, 50-73 atomic-% iron, and 12-20 atomic-% chromium.
Claim 19
Dependent Claim
11 words
An iron-chromium-uranium alloy according to claim 11 containing 12-20 atomic-percent chromium.
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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) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |