EP0227596B1 - Verfahren und Vorrichtung zur Leitung der Abkühlgeschwindigkeit eines Gussstranges - Google Patents

Verfahren und Vorrichtung zur Leitung der Abkühlgeschwindigkeit eines Gussstranges Download PDF

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Publication number
EP0227596B1
EP0227596B1 EP86810560A EP86810560A EP0227596B1 EP 0227596 B1 EP0227596 B1 EP 0227596B1 EP 86810560 A EP86810560 A EP 86810560A EP 86810560 A EP86810560 A EP 86810560A EP 0227596 B1 EP0227596 B1 EP 0227596B1
Authority
EP
European Patent Office
Prior art keywords
coolant
temperature
process according
continuous
continuous casting
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.)
Expired - Lifetime
Application number
EP86810560A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0227596A1 (de
Inventor
Urs BÄNNINGER
Kurt Buxmann
Miroslaw Plata
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.)
3A Composites International AG
Original Assignee
Schweizerische Aluminium AG
Alusuisse Lonza Services Ltd
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 Schweizerische Aluminium AG, Alusuisse Lonza Services Ltd filed Critical Schweizerische Aluminium AG
Priority to AT86810560T priority Critical patent/ATE50177T1/de
Publication of EP0227596A1 publication Critical patent/EP0227596A1/de
Application granted granted Critical
Publication of EP0227596B1 publication Critical patent/EP0227596B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/124—Accessories for subsequent treating or working cast stock in situ for cooling
    • 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
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/049—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds for direct chill casting, e.g. electromagnetic casting

Definitions

  • the invention relates to a method for regulating the cooling speed of a casting strand emerging from a continuous casting mold, which is cooled directly by applying a fluid coolant to the surface of the strand, by regulating the cooling capacity of the coolant, comprising continuous measurement of the cooling capacity, comparing these measured values with the reference variable of the required Cooling capacity and control of the composition and / or the time-related delivery quantity of the coolant for adjustment to the reference variable, the measurement of the cooling capacity using coolant not coming into contact with the cast strand being carried out at at least one point outside the cast strand.
  • heat is withdrawn from the casting strand emerging from the mold by applying a fluid coolant directly below the mold to the surface of the strand.
  • the rate of heat removal and the resulting cooling rate influence to a large extent the structure of the cast strand and in particular the configuration of the cast strand surface.
  • the coolant is usually dispensed in a constant amount over time from the start of casting until the casting is stopped.
  • a number of methods and devices were developed that help change - usually reduce - the cooling intensity in this phase.
  • EP-B-0 015 870 proposes a fine regulation of the angle and point of impact of the coolant by means of a controlled deflection of the coolant beam in order to reduce the solidification conditions of the various casting alloys and to be able to optimally adapt casting speeds.
  • EP-B-062 606 in order to avoid a convex curvature of the strand base due to non-stationary cooling conditions in the sprue phase, a deflection surface with recesses that can be moved parallel to the cast strand axis is provided, which is inserted into the path of the coolant at least in the sprue phase.
  • EP-B-0 082 810 describes a further method for reducing the curvature of the strand foot that occurs when the strand is cooled too abruptly.
  • a substance is mixed into the coolant which, when it hits the hot surface of the strand, releases a gas as a decomposition product, which contains an insulating film which reduces the outflow of heat.
  • EP-A-0 127 577 also discloses a process for continuous casting in which the resulting strand is cooled by means of water containing carbon dioxide, the amount of carbon dioxide added being kept constant during the start-up process, but its concentration within the coolant being increased of the water inflow is reduced and at the same time the thermal contact between the strand surface and the coolant is increased.
  • the supply of carbon dioxide should be interrupted after the start-up process or after falling below a certain carbon dioxide concentration value.
  • DE-A-19 41 816 discloses a method for regulating the cooling rate of elongated, moving, hot objects made of aluminum or aluminum alloys - in particular of cast strands emerging from the mold - in which the regulation of Cooling rate depends on the surface temperature of the moving object.
  • the regulation of Cooling rate depends on the surface temperature of the moving object.
  • the invention is therefore based on the object of providing a method of the type mentioned at the outset by means of which the contribution of the cooling power of the coolant to the regulation of the cooling rate of the cast strand can be controlled without disturbing the immediate surroundings of this cast strand or being disturbed by it .
  • the object is achieved according to the invention in that a part of the coolant is at a defined temperature above the coolant temperature at at least one measuring point located outside the cast strand is steered and there the cooling capacity is monitored by means of temperature measurements.
  • the coolant used for the measurement must not have come into contact with the cast strand within the same cycle.
  • the coolant can be supplied to the cast strand surface, or can be removed or recycled directly.
  • Deviations from a predetermined target profile of the measured temperature trigger a correction of the coolant composition and / or the coolant pressure. It is particularly favorable to choose the measuring point temperature as close as possible to the surface temperature of the cast strand in the area of the coolant impact. In any case, the deviation of the absolute temperatures should not exceed 20%. This can limit the risk of large, temperature-related differences in the qualitative cooling behavior.
  • An expedient embodiment consists in directing the part of the coolant intended for the measurement onto a locally controlled heated body.
  • the heating can act continuously or at defined intervals on the area of the body that serves as the measuring point.
  • the following two methods have proven to be particularly suitable for fulfilling the high requirements of cooling performance measurement: the temperature of the measuring point to which the coolant is applied is kept constant, the heating power required for this is measured and compared with a predetermined reference variable, after which the coolant is measured according to the Deviation is influenced.
  • the second method consists in not heating the measuring point during a given time interval or only in heating it with reduced power and to use the resulting temperature drop as a measure of the current coolant output. Between these intervals, the area of the body serving as the measuring point is heated again to the original temperature.
  • a preferred method within the scope of the invention uses measuring points, in the area of which the coolant hits directly, as well as those in a trickle zone, in which the coolant already encountered flows along the surface of the body, essentially parallel to it. Information from these different cooling zones enables additional conclusions, which serve to specifically correct the various influencing variables of the coolant performance.
  • the method according to the invention is preferably to be applied to the control of the cooling rate of a casting strand emerging from a continuous casting mold, which is cooled directly onto the surface of the strand by applying coolants which in the process release a gas.
  • the reduction in the coolant output that generally occurs due to the released gas is recorded particularly realistically in the measurements in this method.
  • the advantage of the spatial separation of the casting zone and the measuring zone in the method according to the invention is particularly evident when it is used for the contactless continuous casting of metals in an alternating electromagnetic field. Since the cast strand is almost exclusively solidified by the fluid coolant, regulating the performance of the same is of the utmost importance.
  • the body carrying the measuring point is attached to the side of the coolant container facing away from the cast strand.
  • the body can, however, also be positioned or installed in conventional components of the continuous casting installation in such a way that at least part of the coolant hits the measuring point on its way to the coolant container to the cast strand surface.
  • the solution of the task according to the invention is to equip a continuous casting installation with control elements which act on the composition and / or the time-related amount of the coolant dispensed.
  • the object is achieved in that at least one of the coolant nozzles is directed at a measuring point of a body with good thermal conductivity, a heating device acting on the measuring point of the body and at least one temperature sensor installed beneath the surface of the measuring point of the body being provided, and wherein Temperature sensors, heating device and actuators. are connected to a data processing system.
  • the heating device can be designed, for example, as an electrical resistance heater or as an induction coil.
  • the area determined as the measuring point of the body does not have to be able to be heated in the measuring position in every embodiment; Devices are also within the scope of the invention in which the measuring points for heating can be brought into a heating position that deviates from the measuring position.
  • a particularly expedient version of the continuous casting installation has two built-in temperature sensors in the measuring point body, which are arranged at a mutual distance of 20 to 200 mm in such a way that one coolant nozzle is directed directly at one of these temperature sensors and the other in the direction of the coolant flowing away lies.
  • the surface of the body is preferably designed in such a way that the path of the incoming and outflowing coolant is approximately the same as the corresponding path of the coolant in the cast strand.
  • the continuous casting installation according to the invention is intended for casting ingots with a rectangular cross-section - for example strips - it is advantageous to arrange bodies carrying measuring points both in the area of the cross-sectional corners and in the area of the center of the cross-sectional longitudinal sides. In particular due to the location below Deviations in the coolant performance occurring under different pressure ratios of the coolant can hereby be recorded and taken into account when optimizing the coolant condition.
  • 1 and 2 each show a schematic cross section through part of a continuous casting installation according to the invention with a cast strand.
  • the electromagnetic continuous casting plants shown in FIGS. 1 and 2 have an inductor 8, a coolant tank 3 with coolant nozzles 2 and a screen 9.
  • the system shown in Figure 1 has a body 1 which is attached to the coolant tank 3 on its side facing away from the cast strand 10. The coolant emerges from the coolant container 3 and flows through an opening between the inductor 8 and the screen 9 onto the surface of the cast strand 10.
  • the cast strand 10 consists of the aluminum alloy AA 3004 and has a rectangular cross section of 500 mm x 1600 mm. Approx. 600 liters of coolant are applied to the cast strand surface every minute.
  • the coolant container 3 contains a mixture of water and NaHCOs in a weight fraction of approx. 0.3%. After the pouring phase, with a cast strand length of 100 mm, the addition of NaHC03 in the coolant tank 3 is stopped.
  • a partial flow from the coolant tank 3 is directed through a coolant nozzle 2 to a first measuring point of the body 1.
  • a temperature sensor 5 is installed under the impact area. This directly measures the surface temperature and is of the type of the temperature probe described in EP-A-0 162 809.
  • An analog temperature sensor 5 ' is installed vertically below this at a distance of 70 mm. This second measuring point lies in the outflow area of the coolant which has impinged on the first measuring point.
  • the area of the body 1 comprising the two temperature sensors 5, 5 ′ is heated in a controlled manner by a built-in heating device 4, which is designed as an electrical resistance heater. The heating power required to maintain a constant mean temperature is measured and the corresponding information is transmitted to a data processing system 7.
  • the mean temperature is calculated from the temperature values measured with the temperature sensors 5 and 5 'and transmitted to the data processing system 7.
  • the cast strand surface charged with the coolant has a temperature of approximately 420 ° C. in the area of impact.
  • the first measuring point of the body 1 is kept at a temperature of about 450 ° C. in the temperature sensor 5.
  • a CO 2 gas is split off from the NaHCO 3 contained in the coolant in the pouring phase, which forms a film there, which considerably reduces the cooling capacity compared to pure water.
  • the coolant tank 3 is provided on the supply side with actuators 6, which act on the one hand on the NaHC0 3 dosage and on the other hand influence the water pressure.
  • the actuators 6 are connected to the data processing system 7 and are controlled by this on the basis of a comparison of the information coming from the heating device 4 and from the temperature sensors 5, 5 ′ with predetermined reference variables.
  • the embodiment shown in FIG. 2 uses the screen 9 as the body 1.
  • the measuring points are arranged on the inside of the screen 9 in such a way that they are struck by the coolant which flows from the coolant tank 3 to the cast strand 10.
  • Temperature sensors 5 are installed at the measuring point under the surface of the screen 9.
  • the inductor 8 acts as a heating device 4, which keeps the screen 9 at an equilibrium temperature at constant current and constant cooling capacity of the coolant.
  • the temperature sensors 5 are connected to a data processing system 7, which in turn is connected to the actuators 6 attached to the coolant tank 3 and receives information about the current intensity prevailing in the inductor 8.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Heat Treatments In General, Especially Conveying And Cooling (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
EP86810560A 1985-12-09 1986-12-04 Verfahren und Vorrichtung zur Leitung der Abkühlgeschwindigkeit eines Gussstranges Expired - Lifetime EP0227596B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86810560T ATE50177T1 (de) 1985-12-09 1986-12-04 Verfahren und vorrichtung zur leitung der abkuehlgeschwindigkeit eines gussstranges.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH525885 1985-12-09
CH5258/85 1985-12-09

Publications (2)

Publication Number Publication Date
EP0227596A1 EP0227596A1 (de) 1987-07-01
EP0227596B1 true EP0227596B1 (de) 1990-02-07

Family

ID=4290589

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86810560A Expired - Lifetime EP0227596B1 (de) 1985-12-09 1986-12-04 Verfahren und Vorrichtung zur Leitung der Abkühlgeschwindigkeit eines Gussstranges

Country Status (10)

Country Link
US (1) US4756357A (es)
EP (1) EP0227596B1 (es)
JP (1) JPS62137146A (es)
AT (1) ATE50177T1 (es)
AU (1) AU588650B2 (es)
CA (1) CA1275780C (es)
DE (1) DE3668811D1 (es)
ES (1) ES2012770B3 (es)
NO (1) NO166847C (es)
ZA (1) ZA869250B (es)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5918473A (en) * 1997-05-09 1999-07-06 Alcan International Limited Method and apparatus for measuring quenchant properties of coolants
US6056041A (en) * 1997-06-12 2000-05-02 Alcan International Limited Method and apparatus for controlling the temperature of an ingot during casting, particularly at start up
US6412543B1 (en) 2001-03-07 2002-07-02 Nnorthrop Grumman Corporation Method for controlling solidification rate of a mold-cast structure
US7617863B2 (en) * 2006-08-11 2009-11-17 Rti International Metals, Inc. Method and apparatus for temperature control in a continuous casting furnace
WO2017198500A1 (fr) 2016-05-17 2017-11-23 Gap Engineering Sa Moule de coulée semi-continue verticale comportant un dispositif de refroidissement

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE882481C (de) * 1951-07-01 1953-07-09 Boehler & Co A G Geb Verfahren und Vorrichtung zum Stranggiessen von Eisen und Stahl
CH552423A (de) * 1972-04-18 1974-08-15 Concast Ag Verfahren und vorrichtung zum steuern des waermeentzuges in kokillen beim stranggiessen.
US4006633A (en) * 1976-04-22 1977-02-08 Bethlehem Steel Corporation Method and apparatus for determining heat removal from a continuous caster
US4166495A (en) * 1978-03-13 1979-09-04 Aluminum Company Of America Ingot casting method
SU935206A1 (ru) * 1980-06-02 1982-06-15 Всесоюзный Научно-Исследовательский Институт Автоматизации Черной Металлургии Устройство дл автоматического определени интенсивности охлаждени слитка в кристаллизаторе установки непрерывной разливки металла
DE3048711C2 (de) * 1980-12-23 1991-08-01 Hamburger Stahlwerke Gmbh, 2103 Hamburg Verfahren zum Kühlen von Strängen beim Stranggießen von Stahlknüppeln
JPS59199155A (ja) * 1983-04-28 1984-11-12 Sumitomo Heavy Ind Ltd 連続鋳造設備における鋳片の表面温度制御方法
US4530404A (en) * 1983-07-07 1985-07-23 Aluminium Pechiney Process for the electromagnetic casting of metals involving the use of at least one magnetic field which differs from the field of confinement
SU1109249A1 (ru) * 1983-09-27 1984-08-23 Всесоюзный Научно-Исследовательский Институт Автоматизации Черной Металлургии Научно-Производственного Объединения "Черметавтоматика" Устройство дл контрол толщины оболочки слитка в кристаллизаторе машины непрерывного лить металла

Also Published As

Publication number Publication date
ES2012770B3 (es) 1990-04-16
US4756357A (en) 1988-07-12
DE3668811D1 (de) 1990-03-15
CA1275780C (en) 1990-11-06
AU6576586A (en) 1987-06-11
ATE50177T1 (de) 1990-02-15
AU588650B2 (en) 1989-09-21
ZA869250B (en) 1987-11-25
NO166847C (no) 1991-09-11
NO864891L (no) 1987-06-10
NO864891D0 (no) 1986-12-05
NO166847B (no) 1991-06-03
EP0227596A1 (de) 1987-07-01
JPS62137146A (ja) 1987-06-20

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