AU3983389A - Creation of Inventions and Patents with Artificial Intelligence

AU3983389A – Cold hearth refining apparatus and method
– Google Patents

AU3983389A – Cold hearth refining apparatus and method
– Google Patents
Cold hearth refining apparatus and method

Info

Publication number
AU3983389A

AU3983389A
AU39833/89A
AU3983389A
AU3983389A
AU 3983389 A
AU3983389 A
AU 3983389A
AU 39833/89 A
AU39833/89 A
AU 39833/89A
AU 3983389 A
AU3983389 A
AU 3983389A
AU 3983389 A
AU3983389 A
AU 3983389A
Authority
AU
Australia
Prior art keywords
hearth
region
refining
melting
energy
Prior art date
1988-07-11
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Granted

Application number
AU39833/89A
Other versions

AU608459B2
(en

Inventor
Howard R. Harker
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Axel Johnson Metals Inc

Original Assignee
Axel Johnson Metals Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1988-07-11
Filing date
1989-07-07
Publication date
1990-02-05

1989-07-07
Application filed by Axel Johnson Metals Inc
filed
Critical
Axel Johnson Metals Inc

1990-02-05
Publication of AU3983389A
publication
Critical
patent/AU3983389A/en

1991-03-28
Application granted
granted
Critical

1991-03-28
Publication of AU608459B2
publication
Critical
patent/AU608459B2/en

2009-07-07
Anticipated expiration
legal-status
Critical

Status
Ceased
legal-status
Critical
Current

Links

Espacenet

Global Dossier

Discuss

Classifications

C—CHEMISTRY; METALLURGY

C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS

C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals

C22B9/16—Remelting metals

C22B9/22—Remelting metals with heating by wave energy or particle radiation

C22B9/226—Remelting metals with heating by wave energy or particle radiation by electric discharge, e.g. plasma

B—PERFORMING OPERATIONS; TRANSPORTING

B22—CASTING; POWDER METALLURGY

B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES

B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths

B22D11/10—Supplying or treating molten metal

B22D11/11—Treating the molten metal

C—CHEMISTRY; METALLURGY

C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS

C22B34/00—Obtaining refractory metals

C22B34/10—Obtaining titanium, zirconium or hafnium

C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 – C01G23/08

C22B34/1295—Refining, melting, remelting, working up of titanium

C—CHEMISTRY; METALLURGY

C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS

C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals

C22B9/16—Remelting metals

C22B9/22—Remelting metals with heating by wave energy or particle radiation

C22B9/228—Remelting metals with heating by wave energy or particle radiation by particle radiation, e.g. electron beams

Description

Description
COLD HEARTH REFINING APPARATUS AND METHOD
Technical Field
This invention relates to cold hearth refining of metals such as titanium alloys which must be completely free of unrefined inclusions and, more particularly, to a new and improved cold hearth ar¬ rangement which is especially adapted to prevent contamination of refined metal.
Background of the Invention
In applications wherein metals such as titanium alloys which have been refined by cold hearth refining are used in aircraft engine parts, for example, the presence of tiny amounts of unrefined inclusions in the refined ingot is severely detrimental. Since such inclusions may, for example, result in fracture and disintegration of aircraft engine parts rotating at very high speed, they should be completely avoided.
In conventional cold hearth refining of -metals such as titanium alloys, a water-cooled hearth is supplied with lumps or pieces of titanium sponge or machine turnings of titanium alloy consisting of scrap from the manufacture of titanium alloy parts. This material is introduced by gravity feed at one end of a cooled, elongated hearth in a furnace in which the material is first melted and then refined by energy iiϊput from electron beam impingement or plasma torches. The refined molten material is poured from the opposite end of the hearth into a cylindrical mold where it forms a vertically disposed cylindrical ingot that is withdrawn downwardly within the mold as it solidifies.
In conventional cold hearth furnaces used for refining of titanium alloy or the like, in which com-

pacted briquettes and large solid fragments of titanium alloy material are introduced into the melting region, unmelted portions of the alloy material may roll or float downstream from the melting region into the refining region of the hearth so as to contaminate the refined metal in the casting region. Light solids, such as chopped tubing, may also escape complete melting and float into the refining region, causing the same problem. Heretofore, efforts have been made to separate different portions of the hearth in cold hearth refining systems by mounting physical barriers, such as dams or partitions, in the hearth. In the Hunt Patent No. 3,343,828, for example, an elongated flow path is formed in the hearth by providing partial dividers made of graphite which extend alternately from the opposite sides of the hearth to define a serpentine path. This arrangement is not only expensive, but also is incapable of variation without complete reconstruction of the hearth. The Heimerl Patent No. 3,748,070 discloses the formation of dams or barriers between one hearth region and another by the provision of cooling bodies at a selected location either within the hearth itself or positioned in contact with the surface of the molten material, causing the molten material to solidify and form a barrier in the immediate vicinity of the cooling body. This arrangement also requires additional hearth structure with a corresponding increase in cost and is- incapable of modification without reconstructing the hearth.
Disclosure of the Invention
Accordingly, it is an object of the present invention to provide a new and improved cold hearth refining arrangement which overcomes the above- mentioned disadvantages of the prior art.

Another object of the invention is to provide a new and improved cold hearth refining arrangement providing a separation between the melting region and the refining region of the hearth which is capable of structural modification without disassembly of the hearth.
These and other objects of the invention are attained by providing a cold hearth having an inlet end to receive material to be melted and refined and an outlet end and wherein a skull is formed by solidification of molten material, and a controlled energy input arrangement for directing energy to selected regions of the hearth in a desired manner so as to cause the formation of partial barriers of skull material located between the inlet end and the outlet end of the hearth. In one embodiment, the partial barrier of skull material comprises a dam with a narrow neck forming an outflow channel from the melting region to the refining region. In another form, the partial barrier comprises peninsulas of skull materia”. extending in spaced relation from opposite sides of the hearth to form a labyrinth between the melting region and the refining region. In each case, the melting region is sufficiently iso- lated from the refining region that the transfer of unmelted material into the refining region is effectively eliminated.
Further objects and advantages of the invention will be apparent from a reading of the following description in conjunction with the accompanying drawings, in which:
Brief Description of the Drawings
Fig. 1 is a schematic view in longitudinal section illustrating a representative cold hearth ar- rangement in accordance with the present invention; “” Fig. 2 is a plan view of the embodiment illustrated in Fig. 1; and

Fig. 3 is a plan view showing another embodiment cf the invention.-
3est Mode for Carrying Out the Invention
In the typical embodiment of the invention shown in Figs. 1 and 2, a hearth 10 comprises a hearth bed 11 containing cooling pipes 12 through which water or another cooling liquid may be circulated. At the inlet end of the hearth, a chute 13 directs pieces 14 of the raw material to be refined, such as titanium sponge or titanium alloy turnings, into the hearth. In the illustrated embodiment, an energy input is provided by a series of conventional directed energy input devices 15 which produce controllable patterns of energy beams 16 directed selectively to desired regions of the hearth to heat the material 14 to be melted and to refine the molten material in a desired manner. The energy input devices 15 may constitute conventional electron beam guns or conventional plasma torches which are directionally controllable. In the arrangement shown in Fig. 1, one of the energy beams 16 is concentrated on the raw material 14 in a melting region 17 of the hearth so as to melt that material and the other beams 16 are controlled to cover a refining region 18 so as to refine the molten material 19 passing through that region as it flows toward a pouring lip 20 at the other end of the hearth. Because the hearth bed 11 is cooled by liquid flowing through the pipes 12, a solid skull 21 of molten material forms on the inner surface of the hearth bed 11, protecting it from degradation by the molten material.
The refined metal 19 flows from the hearth through the pouring lip 20 into a vertical mold 21. Cooling pipes 22 are provided in the mold 21 to cool the molten material, forming an ingot 23 which is — gradually moved downwardly within the mold in a conventional manner as indicated by the arrow. An

energy input device 24 directs a beam of energy 25 in a controlled manner toward the surface of the molten material 26 at the top of the moid so as to control zhe cooling and solidification of that material into the ingot 23 in a desired manner. If electron beams are used as the energy input, the entire arrangement is, of course, contained within a sealed enclosure (not shown) and maintained at a high vacuum in the conventional manner. As illustrated in Figs. 1 and 2, solid material introduced into the melting region 17 of the hearth remains unmelted for a period of time. If such unmelted material passes into the refining region 18 of the mold, it may contaminate the molten material 19 which will then carry contaminants with it as it flows through the pouring lip 20 into the mold 21. In order to prevent such contamination in accordance with the invention, the directional pattern of energy input, such as the orientation of plasma torches, or the direction of beams 16 produced by the energy input devices 15 of Fig. 1 is controlled so as to avoid heating of selected portions of the alloy material in the hearth, permitting growth of the skull 21* to form a dam extending above the surface of the molten material from each side of the hearth toward the center. The energy input pattern is controlled to provide a narrow and shallow passage 28 of molten material, permitting controlled flow of the material from the melting region 17 to the refining region 18. In this way, the introduction of unmelted material into the refining^region and corresponding contamination of the material in the ingot 23 is effectively prevented.
In the embodiment shown in Fig. 3, the barrier arrangement between the melting region 17 and the refining region 18 of the hearth is provided by controlling the energy input pattern so as to permit the skull material to form two adjacent spaced

peninsulas 29 and 30 extending from each side of the hearth toward the opposite side. This leaves a serpentine channel 31 for the flow of molten material between the melting regio 17 and the refining region 18, permitting extended exposure of any unmelted material to the energy input from electron beams or plasma torches so as to assure complete melting of that material before it reaches the refining region 18. With the arrangements shown in Figs. 1-3 in accordance with the present invention, metals such as titanium alloy can be refined in a cold hearth furnace without concern over possible inclusions which might result from unmelted material passing into the refining region and then being carried into the ingot so as to contaminate the resulting material. It will be understood, of course, that the invention is not restricted to the use of a single hearth and may be used in cold hearth refining systems having two or more hearths and, if desired, the skull barriers formed in accordance with the present invention may be provided in only the first hearth or in two or more successive hearths.
Although the invention has been described herein with reference to specific embodiments, many modifications and variations therein will readily occur to those skilled in the art. Accordingly, all such variations and modifications are included within the intended scope of the invention.

Claims (10)

Cla ims

1. A cold hearth arrangement comprising hearth means having a melting region adjacent to one end to receive solid raw material which is to be melted and a refining region spaced from the melting region, energy ‘input means for applying energy in a controlled manner to the hearth to melt the solid material in the melting region and refine the material in the refining region, cooling means for cooling molten material to form a skull of the material being refined in the hearth, and skull means formed of solidified material provid¬ ing a partial barrier means between the melting region and the refining region of the hearth to prevent unmelted raw material from being trans¬ ported from the melting region to the refining region.

2. A cold hearth arrangement according to Claim 1 wherein the partial barrier means comprises a da extending substantially across the hearth providing a restricted passage for flow of molten material from the melting region to the refining region.

3. A cold hearth arrangement according to Claim 1 wherein the partial barrier means comprises spaced projections from opposite sides of the hearth means providing a serpentine flow path between the melting region and the refining region.

4. A cold hearth arrangement according to Claim 1 wherein the energy input means comprises electron beam gun means.

5. A cold hearth arrangement according to Claim 1 wherein the energy input means comprises plasma torch means.

6. A method for melting and refining material in a cold hearth system comprising supplying solid raw material which is to be melted and refined ,n one region of the hearth, applying energy to the solid material to produce molten material, flowing molten material from the melting region toward a refining region of the hearth spaced from the melting region, cooling the hearth to form a skull of material adjacent to the hearth bed and controlling the application of energy to the hearth so as to cause formation of a partial barrier of skull material between the melting region and the refining region to prevent unmelted raw material from being transported from the melting region to the refining region.

7. A method according to Claim 6 wherein the application of energy is controlled to provide a dam extending substantially across the hearth, providing a restricted passage for flow of molten material from the melting region to the refining region.

8. A method according to Claim 6 wherein the application of energy is controlled to produce spaced projections of skull material from opposite sides of the hearth, providing a ser¬ pentine flow path between the melting region and the refining region.

9. A method according to Claim 6 wherein the energy is applied to the material in the hearth by electron beam gun means.

10. A method according to Claim 6 wherein the energy is applied to the material in the hearth by plasma torch means.

AU39833/89A
1988-07-11
1989-07-07
Cold hearth refining apparatus and method

Ceased

AU608459B2
(en)

Applications Claiming Priority (2)

Application Number
Priority Date
Filing Date
Title

US07/217,566

US4932635A
(en)

1988-07-11
1988-07-11
Cold hearth refining apparatus

US217566

1988-07-11

Publications (2)

Publication Number
Publication Date

AU3983389A
true

AU3983389A
(en)

1990-02-05

AU608459B2

AU608459B2
(en)

1991-03-28

Family
ID=22811599
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

AU39833/89A
Ceased

AU608459B2
(en)

1988-07-11
1989-07-07
Cold hearth refining apparatus and method

Country Status (6)

Country
Link

US
(1)

US4932635A
(en)

EP
(1)

EP0378672B1
(en)

JP
(1)

JPH0814008B2
(en)

AU
(1)

AU608459B2
(en)

DE
(1)

DE68907337T2
(en)

WO
(1)

WO1990000627A1
(en)

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Publication number
Priority date
Publication date
Assignee
Title

AU629134B2
(en)

1990-07-19
1992-09-24
Axel Johnson Metals, Inc.
Vacuum processing of reactive metal

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1991-09-13
1994-03-08
Axel Johnson Metals, Inc.
Static vacuum casting of ingots

US5185031A
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1991-12-31
1993-02-09
Martin Marietta Energy Systems, Inc.
Device and method for skull-melting depth measurement

JP3007942B2
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1992-04-24
2000-02-14
石川島播磨重工業株式会社

Metal strip casting method and apparatus

AU657039B2
(en)

1992-04-24
1995-02-23
Ishikawajima-Harima Heavy Industries Company Limited
Casting metal strip

US5503655A
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1994-02-23
1996-04-02
Orbit Technologies, Inc.
Low cost titanium production

KR960017691A
(en)

1994-11-16
1996-06-17
남일

Manufacturing method of new rubber vulcanizing agent mainly based on zinc oxide

US5972282A
(en)

1997-08-04
1999-10-26
Oregon Metallurgical Corporation
Straight hearth furnace for titanium refining

US6175585B1
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1999-07-15
2001-01-16
Oregon Metallurgical Corporation
Electron beam shielding apparatus and methods for shielding electron beams

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1999-09-03
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Ati Properties, Inc.
Purification hearth

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Refining and casting apparatus and method

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Ati Properties, Inc.
Refining and casting apparatus and method

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Blackburn Allan E.
Method and apparatus for perimeter cleaning in cold hearth refining

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Method and apparatus for cleaning the periphery in a cryogenic furnace refining

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エイティーアイ・プロパティーズ・インコーポレーテッド

Melting furnace including wire discharge ion plasma electron emitter

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2007-12-04
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Ati Properties, Inc.
Casting apparatus and method

KR101311580B1
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2009-03-27
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티타늄 메탈스 코포레이션
Method and apparatus for semi-continuous casting of hollow ingots

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Ati Properties, Inc.
Processes, systems, and apparatus for forming products from atomized metals and alloys

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2021-10-19
Ati Properties Llc
Systems and methods for casting metallic materials

JP5639548B2
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2011-08-22
2014-12-10
株式会社神戸製鋼所

Titanium ingot manufacturing method

JP5787726B2
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2011-11-07
2015-09-30
東邦チタニウム株式会社

Metal dissolution method

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Ati Properties, Inc.
Tapered hearth

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2016-11-17
Ati Properties, Inc.
Methods and apparatuses for producing metallic powder material

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Ніппон Стіл Корпорейшн
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1988-07-11
US
US07/217,566
patent/US4932635A/en
not_active
Expired – Lifetime

1989

1989-07-07
JP
JP1508053A
patent/JPH0814008B2/en
not_active
Expired – Lifetime

1989-07-07
DE
DE89908621T
patent/DE68907337T2/en
not_active
Expired – Fee Related

1989-07-07
WO
PCT/US1989/002960
patent/WO1990000627A1/en
active
IP Right Grant

1989-07-07
AU
AU39833/89A
patent/AU608459B2/en
not_active
Ceased

1989-07-07
EP
EP89908621A
patent/EP0378672B1/en
not_active
Expired – Lifetime

Cited By (1)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

AU629134B2
(en)

1990-07-19
1992-09-24
Axel Johnson Metals, Inc.
Vacuum processing of reactive metal

Also Published As

Publication number
Publication date

DE68907337D1
(en)

1993-07-29

EP0378672A1
(en)

1990-07-25

AU608459B2
(en)

1991-03-28

DE68907337T2
(en)

1993-09-30

EP0378672B1
(en)

1993-06-23

US4932635A
(en)

1990-06-12

JPH0814008B2
(en)

1996-02-14

WO1990000627A1
(en)

1990-01-25

EP0378672A4
(en)

1990-12-27

JPH02503697A
(en)

1990-11-01

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