EP0189313A2 - Procédé et dispositif pour compenser la perte de pression métallostatique pendant la coulée d'un métal liquide sur une surface refroidie mouvante - Google Patents

Procédé et dispositif pour compenser la perte de pression métallostatique pendant la coulée d'un métal liquide sur une surface refroidie mouvante Download PDF

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Publication number
EP0189313A2
EP0189313A2 EP86300408A EP86300408A EP0189313A2 EP 0189313 A2 EP0189313 A2 EP 0189313A2 EP 86300408 A EP86300408 A EP 86300408A EP 86300408 A EP86300408 A EP 86300408A EP 0189313 A2 EP0189313 A2 EP 0189313A2
Authority
EP
European Patent Office
Prior art keywords
molten metal
container
gas pressure
pressure
chamber
Prior art date
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.)
Withdrawn
Application number
EP86300408A
Other languages
German (de)
English (en)
Other versions
EP0189313A3 (fr
Inventor
William Garfield Hall
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.)
Johnson Matthey PLC
Original Assignee
Johnson Matthey PLC
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.)
Filing date
Publication date
Application filed by Johnson Matthey PLC filed Critical Johnson Matthey PLC
Publication of EP0189313A2 publication Critical patent/EP0189313A2/fr
Publication of EP0189313A3 publication Critical patent/EP0189313A3/fr
Withdrawn legal-status Critical Current

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    • 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
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B22D11/0637—Accessories therefor
    • B22D11/064—Accessories therefor for supplying molten metal
    • 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
    • B22D11/16—Controlling or regulating processes or operations
    • B22D11/18—Controlling or regulating processes or operations for pouring
    • B22D11/181—Controlling or regulating processes or operations for pouring responsive to molten metal level or slag level

Definitions

  • This invention relates to a method and a device for compensating for loss of metallostatic pressure during casting of molten metal under positive or negative gas pressure from a slit in a container onto a moving chilled surface.
  • a further problem associated with metal casting processes of this type is that monitoring the thickness of the metal casting by mechanical means is difficult. Therefore it is an object of a refinement of this invention to provide a method and a device for monitoring the thickness of the casting by reference to the rate of increase in the gas pressure in the container.
  • this invention provides in a process for casting molten metal under (positive or negative) gas pressure from a slit in a container onto a moving chilled surface, a method for compensating for pressure variations in the molten metal by varying the gas pressure in the container wherein the method comprises
  • the compensating change in gas pressure in the container is determined by the extent of the penetration of the molten metal into the chamber which in turn is determined in part by the metallostatic pressure in the molten metal.
  • a fall in metallostatic pressure results in molten metal retreating from the chamber and as it moves away from the pre-determined distance, the sensing means produces a response which actuates the pressure varying means to increase the gas pressure in the container so compensating automatically for the fall in metallostatic pressure.
  • an excessive increase in the combination of gas pressure and metallostatic pressure in the container causes molten metal to move back into the chamber producing a counter-response as the pre-determined distance is reached and a consequent decrease in gas pressure in the container.
  • the system quickly settles down to a state in which the molten metal oscillates to and from the pre-determined distance with a vanishingly small amplitude so that the system responds quickly and sensitively to over- or under-compensation with the net result that the gas pressure in the container is increased very steadily as the molten metal is consumed by the casting process. It is preferred that at least at the start of the process, the gas pressure in the chamber is greater than the gas pressure in the container.
  • This invention also provides an apparatus for casting molten metal under (positive or negative) gas pressure from a slit in a container onto a moving chilled surface, a device for compensating for pressure variations in the molten metal by varying the gas pressure in the container wherein the device comprises
  • the sensing means may be for example a float hinged at the pre-determined distance into the chamber so that as molten metal retreats from the pre-determined distance, the float produces a response by falling.
  • the float produces a counter-response by rising.
  • the float can be linked mechanically to the actuating means for the pressure varying means so that the fall (ie response) causes the pressure varying means to increase pressure in the container whilst the rise (ie counter-response) has the opposite effect.
  • the molten metal is sensed electrically by means of an electrically conductive probe which extends downwards into the chamber to the pre-determined distance and forms part of an electrical circuit which also includes the molten metal such that when the molten metal contacts the probe the circuit is closed and current can flow between the metal and the probe and when the metal does not contact the probe the circuit is open and no current flows. Therefore when the molten metal retreats away from contact with the probe, the response produced is a loss of current and when the molten metal moves back into contact, the counter-response produced is a current flow.
  • the presence or absence of a current can be used to operate electrical actuating means for the pressure varying means in such a way that the absence of current causes the actuating means (for example a solenoid) to cause the pressure varying means to increase gas pressure in the container and the presence of current causes the opposite effects.
  • actuating means for example a solenoid
  • the pressure varying means may be any means capable of increasing or decreasing the gas pressure in the container on demand from the actuating means.
  • the simplest means comprises a pressurising line and an evacuating line each closable by valves or by a common valve in such a way that when the pressurising line is open the evacuating line is closed and vice versa.
  • the chamber may be open to atmosphere or it may be closed so that it can be pressurised to super-atmospheric pressures.
  • the use of super-atmospheric pressure in the chamber permits higher gas pressures to be used in the container which in turn leads to faster casting of the molten metal through the slit.
  • a closed chamber also facilitates the use of an inert gas which may be necessary if the molten metal is reactive to air. Likewise the gas in the container may need to be inert.
  • the thickness of the metal casting depends on various parameters such as the speed at which the chilled surface moves, the dimensions of the slit, the clearance between the chilled surface and the slit, the nature of the molten metal (for example its viscosity and density) and the combined gas and metallostatic pressures in the container.
  • these parameters can be pre-selected and kept constant except for the metallostatic pressure which decreases as the molten metal is consumed by the process and the gas pressure which is increased to compensate for the loss of metallostatic pressure. Therefore in normal practice (when in particular the dimensions of the slit and the speed of the chilled surface are kept constant) the rate at which metal is cast and therefore the thickness of the metal casting is directly proportional to the rate of increase in the gas pressure.
  • the apparatus with means for measuring the gas pressure in the container and more preferably with means for measuring the rate of increase of the gas pressure.
  • the invention is illustrated by the following embodiment which is described with reference to the drawing.
  • the drawing is a diagrammatic representation of an apparatus incorporating a device according to this invention.
  • the drawing shows apparatus of the type used for casting molten metal 1 into metal strip 2.
  • Molten metal 1 is contained within container 3 under pressure of a gas in space 4 and cast from slit 5 onto a moving chilled surface 6 provided by wheel 7 which rotates in the direction shown by the arrow.
  • level 8 of metal 1 in container 3 falls reducing the metallostatic pressure in molten metal 1 at slit 5.
  • the problem is to achieve a rapid and sensitive compensation for the reduction in metallostatic pressure whilst minimising the risk of over-compensation.
  • pressurising line 9 into a device which also comprises an evacuating line 10, electrically operated actuating means 11 which can actuate pneumatic opening and closing of valves 9a and 10a provided on lines 9 and 10 respectively, a chamber 12 housing a metal probe 13, a source 14 of electrical energy and wires 15a, b and c.
  • Probe 13, source 14, actuating means 11 and wires 15a, b and c together with metal container 3 and molten metal 1 comprise an open electrical circuit which can be closed by molten metal 1 moving into contact with probe 13.
  • Chamber 12 is defined by sleeve 12a which extends vertically downwards into container 3.
  • Sleeve 12a has a closed upper end 12b which enables chamber 12 to receive a super-atmospheric pressure from pressure line 17 which is closable by valve 18.
  • Lower end 12c of sleeve 12a is open and spaced about 5mm from the base of container 3 so that chamber 12 is in communication with container 3 which enables molten metal 1 to penetrate into chamber 12.
  • Sleeve 12a is electrically isolated from metal container 3 by insulating bushing 16.
  • Electrically conductive metal probe 13 extends vertically downwards into chamber 12 and its tip 20 is located at a pre-determined distance of 15mm above the base of container 3. Probe 13 is electrically isolated from sleeve 12a by insulating plug 16a. When molten metal 1 penetrates into chamber 12 far enough to contact tip 20, a current flows between molten metal 1 and probe 13. Conversely when molten metal 1 retreats from contact with tip 20, no current flows.
  • Actuating means 11 comprises a solenoid (not shown) which actuates pneumatic opening and closing of valves 9a and 10a via pneumatic lines 9b and lOb.
  • the solenoid is arranged so that when actuating means 11 is not receiving current, valve 9a is open and valve 10a is closed which means that pressure line 9 increases the gas pressure in space 4.
  • the solenoid is also arranged so that when actuating means 11 does receive current, valve 9a is closed and valve 10a is open which means that evacuating line 10 decreases the gas pressure in space 4.
  • valve 9a is open and valve 10a is closed so that the gas pressure in space 4 is increased by pressure line 9.
  • the increasing gas pressure in space 4 compensates for the fall in metallostatic pressure and in particular causes molten metal 1 to move back into contact with tip 20 whereupon current again flows to actuating means 11.
  • valve 9a closes and valve 10a opens allowing evacuating line 10 to decrease gas pressure in space 4 causing molten metal 1 to retreat from contact with tip 20.
  • the apparatus is also provided with a conventional instrument 21 for detecting the rate of change of gas pressure in space 4.
  • instrument 21 can be calibrated so as to correlate the rate of change of pressure with the thickness of metal strip 2. Therefore if it is desired to make strip of a different thickness, the gas pressure in chamber 12 can be adjusted leading to a corresponding automatic adjustment of the gas pressure in space 4 and a consequent change in the rate of increase of the gas pressure in space 4 and ultimately a consequent change in the thickness of strip 2.
  • the gas pressure in chamber 4 When level 8 of molten metal 1 in container 3 falls to the level of tip 20, the gas pressure in chamber 4 will become equal to the gas pressure in chamber 12. If it is required to continue operation of the process so that level 8 falls below tip 20, then it will be necessary for the gas pressure in space 4 to be increased so as to exceed that in chamber 12. In short, during the latter stages of the process the gas pressure in chamber 12 may be less than in container 3.
  • molten metal 1 can be replenished by further supplies of molten metal during the casting process.
  • replenishing supplies of molten metal may cause currents within the chamber which could make the control of pressure variations more difficult.
  • sleeve 12a may be made from an electrically non-conducting material such as alumina. This avoids the need to provide insulating bushings and plugs such as 16 and 16a. It also avoids the need for careful alignment of probe 13 for it will not be necessary to ensure probe 13 does not touch sleeve 12a if sleeve 12 a is non-conducting.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
EP86300408A 1985-01-22 1986-01-21 Procédé et dispositif pour compenser la perte de pression métallostatique pendant la coulée d'un métal liquide sur une surface refroidie mouvante Withdrawn EP0189313A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB858501575A GB8501575D0 (en) 1985-01-22 1985-01-22 Device for compensating loss of metallostatic pressure
GB8501575 1985-01-22

Publications (2)

Publication Number Publication Date
EP0189313A2 true EP0189313A2 (fr) 1986-07-30
EP0189313A3 EP0189313A3 (fr) 1988-08-24

Family

ID=10573235

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86300408A Withdrawn EP0189313A3 (fr) 1985-01-22 1986-01-21 Procédé et dispositif pour compenser la perte de pression métallostatique pendant la coulée d'un métal liquide sur une surface refroidie mouvante

Country Status (4)

Country Link
EP (1) EP0189313A3 (fr)
JP (1) JPS61216843A (fr)
DK (1) DK28686A (fr)
GB (1) GB8501575D0 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991015320A2 (fr) * 1990-04-04 1991-10-17 James Herbert Monks Procede et appareil de regulation de l'ecoulement du metal fondu
EP0534174A1 (fr) * 1991-09-27 1993-03-31 Wieland-Werke Ag Procédé et dispositif de fabrication d'une bande de métal proche de sa mesure finale
TR25583A (tr) * 1990-12-20 1993-07-01 Monks James Herbert Erimis madenlerin akisini konturol etmek icin yöntem ve tertibat.
AU648080B2 (en) * 1990-06-01 1994-04-14 Sandvik Ab Method of controlling the flow of outstreaming liquid metal from an inductively heated ladle
WO1994008742A1 (fr) * 1992-10-10 1994-04-28 Sundwiger Eisenhütte Maschinenfabrik Gmbh & Co. Machine a couler les feuillards, constituee d'au moins une surface de refroidissement mobile, en particulier une roue de coulee precedee d'une buse de coulee ou d'un avant-creuset
WO2004112992A2 (fr) * 2003-06-24 2004-12-29 Alcan International Limited Procede de coulage d'un lingot composite
US7975752B2 (en) 2007-02-28 2011-07-12 Novelis Inc. Co-casting of metals by direct chill casting

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3522836A (en) * 1966-07-06 1970-08-04 Battelle Development Corp Method of manufacturing wire and the like
US3538884A (en) * 1965-06-01 1970-11-10 Gen Electric Continuous formation of intermediates
US4220319A (en) * 1978-05-31 1980-09-02 Westofen Gmbh Ovens
JPS56128666A (en) * 1980-03-13 1981-10-08 Nippon Kokan Keishiyu Kk Automatic pouring device
JPS58159957A (ja) * 1982-03-19 1983-09-22 Hitachi Ltd 非晶質金属製造装置の制御方法
US4449568A (en) * 1980-02-28 1984-05-22 Allied Corporation Continuous casting controller

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3538884A (en) * 1965-06-01 1970-11-10 Gen Electric Continuous formation of intermediates
US3522836A (en) * 1966-07-06 1970-08-04 Battelle Development Corp Method of manufacturing wire and the like
US4220319A (en) * 1978-05-31 1980-09-02 Westofen Gmbh Ovens
US4449568A (en) * 1980-02-28 1984-05-22 Allied Corporation Continuous casting controller
JPS56128666A (en) * 1980-03-13 1981-10-08 Nippon Kokan Keishiyu Kk Automatic pouring device
JPS58159957A (ja) * 1982-03-19 1983-09-22 Hitachi Ltd 非晶質金属製造装置の制御方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 6, no. 4 (M-106)[882], 12th January 1982; & JP-A-56 128 666 (NIPPON KOUKAN TSUGITE K.K.) 08-10-1981 *
PATENT ABSTRACTS OF JAPAN, vol. 7. no. 283 (M-263)[1428], 16th December 1983; & JP-A-58 159 957 (HITACHI SEISAKUSHO K.K.) 22-09-83 *

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991015320A2 (fr) * 1990-04-04 1991-10-17 James Herbert Monks Procede et appareil de regulation de l'ecoulement du metal fondu
WO1991015320A3 (fr) * 1990-04-04 1991-11-28 James Herbert Monks Procede et appareil de regulation de l'ecoulement du metal fondu
US5190674A (en) * 1990-04-04 1993-03-02 Monks James H Method and apparatus for controlling the flow of molten metals
AU648080B2 (en) * 1990-06-01 1994-04-14 Sandvik Ab Method of controlling the flow of outstreaming liquid metal from an inductively heated ladle
TR25583A (tr) * 1990-12-20 1993-07-01 Monks James Herbert Erimis madenlerin akisini konturol etmek icin yöntem ve tertibat.
EP0534174A1 (fr) * 1991-09-27 1993-03-31 Wieland-Werke Ag Procédé et dispositif de fabrication d'une bande de métal proche de sa mesure finale
WO1994008742A1 (fr) * 1992-10-10 1994-04-28 Sundwiger Eisenhütte Maschinenfabrik Gmbh & Co. Machine a couler les feuillards, constituee d'au moins une surface de refroidissement mobile, en particulier une roue de coulee precedee d'une buse de coulee ou d'un avant-creuset
WO2004112992A2 (fr) * 2003-06-24 2004-12-29 Alcan International Limited Procede de coulage d'un lingot composite
WO2004112992A3 (fr) * 2003-06-24 2005-04-14 Alcan Int Ltd Procede de coulage d'un lingot composite
US7472740B2 (en) 2003-06-24 2009-01-06 Novelis Inc. Method for casting composite ingot
US7819170B2 (en) 2003-06-24 2010-10-26 Novelis Inc. Method for casting composite ingot
US8312915B2 (en) 2003-06-24 2012-11-20 Novelis Inc. Method for casting composite ingot
US8415025B2 (en) 2003-06-24 2013-04-09 Novelis Inc. Composite metal as cast ingot
US8927113B2 (en) 2003-06-24 2015-01-06 Novelis Inc. Composite metal ingot
US7975752B2 (en) 2007-02-28 2011-07-12 Novelis Inc. Co-casting of metals by direct chill casting

Also Published As

Publication number Publication date
DK28686D0 (da) 1986-01-21
GB8501575D0 (en) 1985-02-20
EP0189313A3 (fr) 1988-08-24
DK28686A (da) 1986-07-23
JPS61216843A (ja) 1986-09-26

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