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Publication numberUS2810640 A
Publication typeGrant
Publication dateOct 22, 1957
Filing dateApr 28, 1955
Priority dateApr 28, 1955
Publication numberUS 2810640 A, US 2810640A, US-A-2810640, US2810640 A, US2810640A
InventorsBolkcom Wilbur T, Knapp William E
Original AssigneeAmerican Metallurg Products Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Master alloys containing rare earth metals
US 2810640 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

MASTER ALLOYS CONTAINING RARE EARTH METALS Wilbur T. Bolkcorn, Allison Park, and William E. Knapp, Pittsburgh, Pa., assignors to American Metallurgical Products (30., Pittsburgh, Pa., a partnership No Drawing. Application April 28, 1955, Serial No. 504,653

13 Claims. (Cl. 75-134) This invention relates to alloys and particularly to an addition alloy for steel and the like metals whereby rare earth metal may be more elfectively incorporated into the matrix metal. The use of rare earth metals as an additive to metals matrices has long been known. The use of the rare earth metals has, however, been somewhat limited by reason of the relatively low efiicienoy upon addition to the base or matrix material. Rare earth metals have generally been added to metal matrices in the form of individual pure rare earth metals or in the form of mixtures such as Misch Metal which is a mixture of rare earth metals in the proportions in which they normally occur in ore bodies.

We have found that the effectiveness of the rare earth metals can be markedly increased by combining them with one or more metals of the group zirconium, titanium and hafnium in the form of an addition alloy. We have found that zirconium, titanium and hafnium may be admixed with the rare earth metals in the following proportions:

Percent Rare earth metals 25 to 93 One or more of the group zirconium, titanium and hafnium 7 to 75 We have found that the rare earth metals and one or more members of the group zirconium, titanium and hafnium in the above proportions may be and preferably is admixed with a diluent to form an addition alloy which has a high density and other desirable properties set out hereinafter. Preferably the diluent is a mixture of metals having a high density and a relatively low melting point. We have found, for example, that manganese and nickel in the proportion of about 1 /2 parts of manganese to 1 part nickel has a high density and a low melting point of about 1750 F. The diluent, however, may be iron, manganese, nickel, copper or similar metals either alone or in combination, to which are added a rare earth metal or rare earth metal mixture and one or more of the group zirconium, titanium and hafnium. Broadly, the addition alloy of our invention may have the following general composition:

Percent One or more of the group zirconium, titanium and hafnium 2 to 25 Rare earth metal to 30 Diluent (preferably 1 /2 parts of manganese to 1 part nickel) Balance Preferably, however, we limited the composition of our addition alloy to a somewhat narrower range. The

preferred alloy has the following composition:

Percent One or more of the group zirconium, titanium and hafnium 2 to 12.

Rare earth metal 10 to 30 Diluent (preferably 1 /2 parts of manganese to 1 part nickel) Balance ited States Patent Patented Oct. 22, 1957 We have found that the alloy of our invention gives a much greater efficiency than the ordinary miseh metal of commerce, for example, in low alloy steel where the rare earth metals are added for improved impact properties, approximately 1 lb. per ton of ordinary miseh metal was required in order to achieve a minimum of 20 lbs. impact level on a V notch charpy test at minus 40 F. with a Brinell hardness of 500. Our new alloy of this invention consisting of 45% manganese, 30% nickel, 20% miseh metal and 5% zirconium, required a total alloy addition of 1 lb. per ton or only 0.2 lb. per ton of rare earth metal. In short, we are able to obtain an identical result with the use of only /5 as much rare earth metal as has been required in the past.

In stainless steel ordinary unprotected miseh metal gives a recovery of only approximately 50% of the rare earth elements, whereas the use of the present alloy permits recovery between to Several stainless steel heats using miseh metal in one series and the alloy of this invention (consisting of 45% manganese, 30% nickel, 20% miseh metal and 5% zirconium) in the other were prepared and the recovery or rare earth metals determined. The results of this study are set out in Table 1 herein below:

the titanium, zirconium or hafnium, as the case may be, appears to flux out residual dirt which sometimes occurs when rare earth metals are used in steel under unfavorable conditions and which has been a deterrent to the use of rare earth metals.

The effectiveness of rare earth metal additions to a base steel is perhaps most strikingly illustrated by a comparison of V notch charpy tests. A series of samples of a steel having 1.48% manganese, 28% carbon, 35% silicon, .0l5% sulphur, .Oll% phosphorus, .63% chromium, 58% molybdenum, .11% nickel and 002% boron were tested both with the addition of our new alloy, standard rare earth miseh metal, and without the addition of any We have found that the addition alloy of the present invention can be made most successfully by incorporating the titanium, zirconium or hafnium in the form of relatively pure metal such as sponge metal or scrap rather than in the form of their ferro alloys. We have found that the usual ferro titanium, ferro zirconium or nickelsilicon-titanium or nickel-silicon-zirconium form high melting intermetallic components when added to the rare earth metals, so that the recovery is relatively low and is extremely variable. For this reason and other reasons which are apparent from the foregoing disclosure the separate addition of rare earth metals and alloys of zirconium,'titanium or hafnium to the molten bath will not produce the unusual advantages characteristic of the addition alloy of our invention.

When we speak of rare earth metals in this application we have reference to that group of metals having atomic members between 58 and 71 of the periodic table. Misch metal is the term comm-only used in the industry for a mixture of rare earth metals produced by reduction from naturally occurring rare earth ores and contains an admixture of various rare earth metals in the approximate proportions in which they occur in the ore. The most common rare earth metals are cerium, lanthanum, neodymium and praseodymium and these metals are the principal constituents of misch metal.

We have set out certain preferred compositions of our alloy and have described a preferred method of making the same. It will be understood, however, that the alloy of this invention may be otherwise made and embodied within the scope of the following claims.

We claim:

1. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of a mixture of about 25% to 93% rare earth metals and about 7% to 75% of one or more metals selected from the group zirconium, titanium and hafnium all incorporated in a suflicient amount of metal diluent of high density compatible with the metal bath to form a mixture whose density is greater than the bath. 2. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of a mix- .ture of about 45% to 93% rare earth metals and about 7% to 55% of one or more metals selected from 'the group zirconium, titanium and hafnium allincorporated in a sufiicient amount of metal diluent of high density compatible with the metal bath to form a mixture whose density is greater than the bath.

3. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of about 10% to 30% rare earth metals, about 2% to of one or more metals selected from the group zirconium, titanium and hafnium and the balance a metal diluent of high density compatible with the metal bath.

4. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of about 10% to 30% rare earth metals, about 2% to 10% of one or w into a metal bath consisting essentially of about 10% to 30% rare earth metals, about 2% to 25 of one or more metals selected from the group zirconium, titanium and hafnium and the balance a metal diluent selected from the group manganese, nickel, copper and iron and mixtures thereof.

6. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of about 10% to 30% rare earth metals, about 2% to 10% of one or more metals selected from the group zirconium, titanium and hafnium and the balance a metal diluent selected from the group manganese, nickel, copper and iron and mixtures thereof.

7. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of about 10% to 30% rare earth metals, about 2% to 25% of one or more metals selected from the group zirconium, titanium and hafnium and the balance made up of manganese and nickel in the proportions of 1 /2 parts of manganese to 1 part of nickel.

8. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of about 10% to 30% rare earth metals, about 2% to 12% of one or more metals selected from the group zirconium, titanium and hafnium and the balance made up of manganese and nickel in the proportions of about 1 /2 parts of manganese to 1 part of nickel.

9. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of about 20% misch metal, 5% zirconium, 30% nickel and 45% manganese.

10. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of about 20% misch metal, 5% titanium, 30% nickel and 45% manganese.

11. The method of adding rare earth metals to a metal bath comprising the steps of forming a molten bath of the metal to be treated, adding to the bath an alloy consisting essentially of about 25% to 93% rare earth metals and about 7% to of one or more metals selected from the group zirconium, titanium and hafnium.

12. The method of adding rare earth metals to a metal bath comprising the steps of forming a molten bath of thev metal to be treated, adding to the bath an admixture consisting essentially of about 10% to 30% rare earth metals, about 2% to 25% of one or more metals selected from the group zirconium, titanium and hafnium and the balance metal diluent of high density compatible with the metal bath.

13. An addition alloy for incorporating rare earth metals into a metal bath consisting essentially of about 10% to 30% rare earth metals, about 2% to 25 of one or more metals seletced from the group zirconium, titanium and hafnium and the balance iron.

References Cited in the file of this patent UNITED STATES PATENTS 1,023,208 Lesmuller Apr. 16, 1912 2,642,358 Kent June 16, 1953 FOREIGN PATENTS 488,322 Great Britain July 5, 1938 498,599 Belgium Feb. 1, 1951

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1023208 *Dec 30, 1908Apr 16, 1912Ludwig WeissProcess for the production of pyrophorous substances for ignition and illumination.
US2642358 *Sep 20, 1949Jun 16, 1953Paula KentCerium base alloy
BE498599A * Title not available
GB488322A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3163744 *Feb 23, 1962Dec 29, 1964United Aircraft CorpNon-consumable arc-melting and arc-welding electrodes
US3446615 *May 11, 1967May 27, 1969Iit Res InstHafnium base alloys
US3505064 *Oct 21, 1965Apr 7, 1970Atomic Energy CommissionHafnium alloy
US3515543 *Nov 28, 1966Jun 2, 1970Imp Metal Ind Kynoch LtdHafnium alloys
US3515544 *Nov 28, 1966Jun 2, 1970Imp Metal Ind Kynoch LtdHafnium alloys
US4121924 *Sep 16, 1976Oct 24, 1978The International Nickel Company, Inc.Alloy for rare earth treatment of molten metals and method
US4221613 *Jan 24, 1979Sep 9, 1980Namiki Precision Jewel Co., Ltd.Rare earth-cobalt system permanent magnetic alloys and method of preparing same
US5200004 *Dec 16, 1991Apr 6, 1993Iowa State University Research Foundation, Inc.High strength, light weight Ti-Y composites and method of making same
USRE31317 *Nov 24, 1980Jul 19, 1983Namiki Precision Jewel Co., Ltd.Rare earth-cobalt system permanent magnetic alloys and method of preparing same
DE1242986B *Dec 22, 1961Jun 22, 1967Kazuji KusakaZusatzlegierung zur Verwendung beim Schweissen und Stahlherstellen
Classifications
U.S. Classification420/580, 420/581, 420/416, 420/83, 420/422, 420/40, 420/417
International ClassificationC22C28/00, C21C7/00
Cooperative ClassificationC21C7/0006, C22C28/00
European ClassificationC21C7/00A, C22C28/00