EP0196242B1 - Verfahren zum Schützen eines Stahlgiessstrahls - Google Patents

Verfahren zum Schützen eines Stahlgiessstrahls Download PDF

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Publication number
EP0196242B1
EP0196242B1 EP86400336A EP86400336A EP0196242B1 EP 0196242 B1 EP0196242 B1 EP 0196242B1 EP 86400336 A EP86400336 A EP 86400336A EP 86400336 A EP86400336 A EP 86400336A EP 0196242 B1 EP0196242 B1 EP 0196242B1
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EP
European Patent Office
Prior art keywords
carbon dioxide
gaseous
vessel
gas
flow
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EP86400336A
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English (en)
French (fr)
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EP0196242A1 (de
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Guy Savard
Robert Gum Hong Lee
Guillermo Garrido
Alan Balding
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Air Liquide Canada Inc
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Air Liquide Canada Inc
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Priority claimed from US06/703,751 external-priority patent/US4614216A/en
Application filed by Air Liquide Canada Inc filed Critical Air Liquide Canada Inc
Priority to AT86400336T priority Critical patent/ATE42227T1/de
Publication of EP0196242A1 publication Critical patent/EP0196242A1/de
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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
    • B22D11/10—Supplying or treating molten metal
    • B22D11/106—Shielding the molten jet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/003—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting by using inert gases

Definitions

  • the present invention relates to a method for protecting a cast steel jet according to the preamble of claim 1.
  • the molten steel produced by any of the conventional methods usually contains a high oxygen content. This reduces the quality of the steel.
  • the steel is calmed or deoxidized by introducing, into the molten steel, deoxidizing agents, for example silicon in the form of ferrosilicon or aluminum or both.
  • deoxidizing agents for example silicon in the form of ferrosilicon or aluminum or both.
  • aluminum calm steel When aluminum is used, the steel is designated as aluminum calm steel and when silicon is used, the steel is designated as silicon calm steel.
  • the intentionally formed non-metallic impurities are allowed to settle and leave the mass of the molten steel, and they are collected at the level of the less dense slag layer floating on the steel.
  • the quenched molten steel has a strong affinity for oxygen, which it captures, when it is exposed to the atmosphere, during its discharge from an oven or during casting in the form of molded ingots, in the form of billets or in the form of slabs.
  • inclusions are formed by reaction of elements normally present in steel in contents of less than 2%, such as, for example, Ca, Mg, AI, Mn, B, Cr, P, Si, Cr, S, either with oxygen or with nitrogen.
  • First formed products are referred to as oxides and the second formed products are designated as nitrides. When molten steel is exposed to air, it can form both oxides and nitrides.
  • Inert gases such as argon and helium are also well known agents used to protect the flow or surface of the molten metal during transfer operations. These gases are relatively rare and therefore expensive. Currently, nitrogen gas is used when the nitride content is not a critical specification of the finished steel product.
  • LU-A-70 560 describes a method of protecting the surface of the molten metal in a continuous casting mold using protective powders which are maintained on the surface of the bath by a gas jet which also surrounds the casting jet of the metal in the mold and keeps the powder on the surface of the metal.
  • FR-A-434 070 describes a process for casting and molding metals in which the molten metal is protected against oxidation using non-oxidizing gases such as carbonic acid.
  • liquid nitrogen provides a level of protection that presents some improvements over other methods.
  • the handling of this substance under the difficult conditions of pouring on the ground makes it difficult to obtain a continuous flow, during the operation.
  • nitrogen has a density close to that of air, which reduces its ability to effectively move air.
  • obtaining an inert state by using nitrogen cannot be used for grades of steel, for which the formation of nitrides is undesirable.
  • carbon dioxide can be used effectively to form a protective gas envelope intended to protect molten steel from any oxidation by the atmosphere, for example during continuous casting, d '' ingot ingots and steel casting from an oven.
  • Carbon dioxide has been used to surround a molten metal such as lead, zinc, copper, metals having a melting point below the dissociation temperature of carbon dioxide. Based on thermodynamic considerations, one would expect that upon contact of carbon dioxide with molten steel, the latter would be oxidized by the dissociation of the gas since its dissociation temperature is significantly lower than that of l '' molten steel (1550 ° C to 1600 ° C at 750 ° C up to 1750'C).
  • the applicants have found, in an unexplained manner, that the kinetics are such that upon contact with the flows of molten steel, obtained under the action of gravity, a gas containing a predominant carbon dioxide content at the gas - metal interface serves to form a layer constituting an effective barrier vis-à-vis the surrounding atmosphere. Not only is oxidation considerably reduced by being brought to a level which it would reach if there was a protective barrier against the atmosphere, but also any contact between molten steel and nitrogen and hydrogen (from moisture in the air) is prevented.
  • the dissociated oxygen uptake provided by the gas in the protective envelope has been found to be less than about 70 parts per million and may be as low as 20 to 30 parts per million.
  • Carbon dioxide is, therefore, capable, alone or in a diluted state with a non-oxidizing gas, of providing an effective barrier between the molten steel and the surrounding atmosphere, which greatly reduces the rate of subsequent oxidation, to the point that this gas can be used as an extremely effective envelope making it possible to protect from any contamination by air, the molten steel transferred from one container to another.
  • C0 2 differs from the use of inert gases such as argon and helium and that of nitrogen, in that good protection can only be obtained if certain parameters are combined with so that the dissociation rate of C0 2 cannot reach a certain important value.
  • inert gases such as argon and helium and that of nitrogen
  • the temperature of the C0 2 gas and the duration of exposure are directly related.
  • the gas forming the protective envelope is actually at ambient temperature when it leaves the apparatus or the diffuser delivering the gas. If one acts in such a way that the stagnant gas is not heated by the metal, the gas is maintained essentially at a temperature below 700 ° C and preferably below 500 ° C thanks to a continuous circulation, which prevents any dissociation.
  • the gas When wrapping a flow or falling jet of molten steel from an upper container to a container or lower mold, the gas must be exposed to the flow of molten metal for a period of time less than 0.15 seconds and preferably for a period of less than 0.1 seconds, and the rate of descent of the gas must be different, i.e. it must be greater or less, by at least minus 1.5 meters / second and preferably more than 3 meters / second, than that of metal.
  • the method described here is preferably applied to steels containing less than 1% of C, 1.5% of Mn, from 0 to 0.02 of AI, of 0.05% of S, of 0.4 of Si , from 0.05% of P, from 0 to 0.005% of Ti and 0 to 0.005% of B.
  • Copper, nickel and carbon monoxide can be between contents lying between 0 and 1%. There may also be traces of residual metals.
  • the process is particularly suitable for calm silicon steels intended to form spikes, tubular metal products, metallic construction products or sheet metal products.
  • the partial pressure of C0 2 should be greater than one atmosphere.
  • the invention envisages using carbon dioxide alone or mixtures of gases containing more than 50% of CO 2 , the remainder being formed by a non-oxidizing gas, for example carbon monoxide, nitrogen or inert gases. such as argon, helium, or one or more of the rare gases.
  • a gas atmosphere containing carbon dioxide is formed, in the form of a protective envelope, around the liquid flow, close to its source, so as to produce a sheath or a gaseous envelope which covers the surface of the steel until it solidifies .
  • the interior of the mold is swept in advance with the gas so as to eliminate the air and to create an atmosphere of gas in the mold, through which the steel is cast.
  • the oxygen content of the mold, before casting in the mold can be reduced essentially to a minimum value, for example to less than 3% by volume and preferably not more than 1%.
  • the flow should not be less than a flow equivalent to about 2.2 cubic meters per minute and preferably be as high as about 3.4 cubic meters per minute to sweep the mold having a volume of about 3 m 3 .
  • the time interval between the end of the purge and the start of the mold casting must be kept to a minimum value and should not exceed approximately 35 seconds and should preferably be between 20 and 30 seconds in order to ensure that the carbon dioxide atmosphere is essentially intact.
  • the envelope can be formed by providing a ring, provided with openings dispensing the gas, around the flow of molten steel, close to its source, at the outlet of the upper enclosure, so as to send the carbon dioxide near the steel flow, in the form of jets which merge to form a sheath or an envelope surrounding the mobile surface of the steel flow and which is entrained with the latter.
  • a ring dispensing the gas can surround the nozzle out of the mold ladle.
  • suitable means can be provided for supplying the gas, so that they deliver carbon dioxide near the flow , so as to envelop the latter in a similar manner.
  • FIG. 1 represents a ladle A containing molten steel which is poured into a mold B.
  • a layer 12 of slag is present at the top of the molten steel.
  • Enveloping gas formed by carbon dioxide is sent via a distribution belt (shown in FIG. 4), via a supply pipe 15.
  • a mold B t which waits to receive molten steel delivered by the ladle, is shown as being subjected to washing with carbon dioxide by means of a pipe 17, and subsequent molds B 3 and B 2 await their turn.
  • a cap 19 consisting of aluminum foil is placed at the top of each mold.
  • the cap 19 has a cut-out local area used to form an opening for the gas supply pipe.
  • Figure 2 shows, in more detail, the mold B t while it is subjected to washing or sweeping with carbon dioxide.
  • Line 17 passes through an opening 20 formed in the cap formed by the aluminum foil and ends with a nozzle 18 by means of which the carbon dioxide is supplied in the lower part of the ladle in order to discharge the air and replace it with a carbon dioxide atmosphere which is maintained almost until the molten metal is poured into the mold.
  • Mold B t has a wall 22 which surrounds a mold cavity of narrowed shape 23.
  • the base of the wall 22 is supported on a fluted metal support 24 carried by the part forming the ceiling of a support device C mounted on rails , so as to establish a seal between the base of the wall 22 and the surface of the ceiling of the support device C, allowing the lateral evacuation of a certain amount of carbon dioxide.
  • a support device is used to take the ingots out of the ingot mold casting span.
  • Sweeping is carried out with carbon dioxide inside the mold B t until its oxygen content is reduced essentially to a minimum value. For example, it has been found possible to reduce the oxygen content to less than 3 and even to a value of not more than 1% by volume. Unexpectedly, the flow rate of the sweeping gas must be high in order to obtain compensation for the conditions encountered, for example due to the heat of the mold and leaks below the mold at the base and between the upper part of the mold and the cover. The oxygen level is essentially kept at a minimum value by continuing the flow of the sweep gas just before the ingot mold casting begins.
  • Mold B and the ladle A are brought into the casting position and the casting operation is carried out as described with reference to Figure 4.
  • a sliding door located in the mold B is opened by remote control, which allows the molten steel to fall into the outlet passage 25 of the ladle A and to circulate in the form of a vertical flow S, after passing through a diffuser 27.
  • the flow leaving the outlet 27 of the ladle has a circular cross section with a diameter between 50 and 100 mm and having a length between 45 and 80 centimeters between the outlet and the C0 2 and the mold.
  • the flow leaving the ladle to enter the pouring funnel should have a diameter of between about 50 millimeters and 100 millimeters and a length of between 30 centimeters and 60 centimeters, while the length of the flow between the pouring funnel and the casting mold should be between about 30 cm and between about 45 cm.
  • Diffuser 27 is supplied with carbon dioxide in the gaseous state coming from a pipe 15, which has the effect that a gas envelope surrounds the flow of the molten steel and is drawn along the latter up to '' inside the carbon dioxide atmosphere present in the mold B. Between the moment it leaves the ladle and the moment it reaches its destination in the mold, the molten steel is protected of the atmosphere by a continuous curtain of gas as described above. Once the mold is filled, the valve of the sliding pouring attack of the ladle is closed, which interrupts the flow of molten steel and the next mold B I and the ladle A are brought in alignment, so that the mold receives its supply of molten steel.
  • Carbon dioxide in the liquid state is stored in a refrigerated and insulated pressure vessel E at a temperature between approximately 17 and 18 ° C. and under a pressure of 20 kilos per square centimeter.
  • the tank E is protected by a safety valve 31, adjusted to 24 kilos per square centimeter.
  • Carbon dioxide is extracted in the form of a vapor from the free space 33 of the tank E, by means of a shut-off valve 34. Drawing off the carbon dioxide vapor from the tank E reduces the pressure in the free space 33.
  • a vaporization device 35 is powered by an energy source (electric, hot water or steam) and is arranged so as to vaporize liquid carbon dioxide and maintain the pressure inside the 'free space 33 when the carbon dioxide is drawn off via the shut-off valve 34 towards the point of use. Additional vaporization devices 32 can be added in parallel in order to maintain the pressure in the free space, when a significant withdrawal of carbon dioxide vapor is carried out via the valve 34.
  • a sensor (not shown) is also provided, which detects the pressure in the free space 33. When the pressure drops below the indicated value, a greater quantity of vapor is sent to the space 33 in order to restore pressure. If the tank remains at rest for a certain time, without delivering steam, the heat increases, as does the pressure. Then a refrigerator (not shown) is started and the steam is cooled.
  • the carbon dioxide vapor leaves the free space 33 in the direction of the shut-off valve 34, at the pressure prevailing in the storage tank (20 kg per square centimeter) to enter an in-line heating device F and which is powered by an external energy source.
  • the role of the heating device F is to add heat which is sensitive to the vapor of the carbon dioxide so that the latter is situated at a temperature at which it can subsequently be expanded without producing a temperature situated outside the operating range of the apparatus which is mounted downstream and which finally delivers the carbon dioxide at the anbiant temperature.
  • the temperature, to which the gas is heated in the heater can be in the range of 100 ° C to 120 ° C.
  • the carbon dioxide vapor circulates, at this temperature, from the in-line heating device F by passing through non-return valves 40 and 41 and by shut-off valves 42 and 43 to end up with regulators 44 and 45 reducing the pressure.
  • Pressure reducing regulators 44 and 45 are set to a pressure which provides the appropriate flow for the requirements downstream.
  • Flow indicating devices or flow meters 46 and 47 are provided and the carbon dioxide flow is controlled by valves 48 and 49.
  • Pressure gauges or indicators 50 and 51 are mounted between regulators 44 and 45 and between the measuring devices 46 and 47 respectively.
  • the gas temperature between regulators 44 and 45 and the flow indicator devices 46 and 47 are in the range between about 5 ° C and about 15 ° C.
  • a ladle having a capacity of 120 tonnes was used and molds each having a volume equal to about 3 m 3 , a capacity of 8 to 9 tonnes, so that each casting of 120 tonnes provided 6 to 9 ingots.
  • the ladle had a circular opening or nozzle with a diameter of 5 to 6.5 cm.
  • Each mold produced ingots with a height of 270 cm and had rectangular sections with an average value of 70 x 160 cm.
  • the distance between the base of the outlet and the upper part of the mold was 75 cm.
  • Each mold rested on a support device mounted on rails (base plate), which is used to extract the solidified ingots from the ingot mold bay.
  • the ladle was fitted with a perforated ring located just below the outlet and capable of forming a protective envelope of carbon dioxide in the gaseous state.
  • This ring was connected to a continuous source of carbon dioxide supply as shown in FIG. 5.
  • the conventional apparatus made it possible to carry out sweeping of the mold with carbon dioxide in the gaseous state.
  • a strong jet of compressed air was introduced into the support device to remove any loose particles.
  • a coating dispersion consisting of cement in dilute phosphoric acid was then applied to the support device.
  • Four strips of corrugated or fluted steel sheet were placed having dimensions of approximately 15 cm x 75 cm x 0.157 cm, in a square or elongated configuration on the support device so as to provide a seat. When the mold has been placed in position on this last, its weight deformed the grooved parts, which reduced the risk of a molten steel leak (see the rotor in Figure 2).
  • An elongated corrugated steel sheet of small caliber having an approximate dimensions of 50 cm x 100 cm x 125 cm was placed on the support device, inside the mold, in order to reduce the intensity of splashing when the start of the molten metal is introduced inside the mold.
  • Exothermic "panels" (“hot upper elements") have been fixed 30 years in height inside the upper part of the mold and which, in contact with the molten steel, deliver heat which slows down the cooling rate at the upper part of the ingot, which reduces the depth of the "channel-shaped shrinkage" at the upper part of this ingot, which must be removed before subsequent rolling.
  • a cover formed of aluminum foil was placed at the top of the mold in order to limit exposure to the atmosphere before performing a purge or a sweep with carbon dioxide.
  • the air was forced out of the interior of the mold by the "purge" carried out with carbon dioxide at a flow rate of approximately 0.675 to 3.25 m 3 under normal conditions, for approximately 3 to 5 minutes before the pouring of each ingot.
  • a rubber hose protected by asbestos was introduced inside the mold through the aluminum sheet so that the diffuser is brought as low as possible, as shown in Figure 2.
  • the flow continued of gas until the air has been removed from the mold, to the point where the oxygen content in the mold was no more than 1% by volume.
  • the sweeping or washing was continued until the casting was carried out in the mold, in order to take account of a gas leak between the mold and its support device.
  • the molten steel drilled a small hole in the aluminum foil, which reduced the amount of ambient air entrained in the mold.
  • the temperature of the steel in the flow was in the range between 1250 ° C and 1650 ° C.
  • a carbon dioxide envelope was formed near the start of the flow, i.e. just below the bottom of the ladle, below the nozzle .
  • the envelope formed around the flow of molten steel was entrained with the latter and formed a layer of gas providing protection from the atmosphere from the moment the steel left the nozzle to the point of impact in the mold.
  • the carbon dioxide flow rate sent to form this envelope was 2.8 meters per minute.
  • the ladle containing the 120 tonnes of steel was placed above the first mold already “purged” and we began to send the gas flow forming the protective envelope. Purge pipe was transferred to the second mold without interrupting the gas flow.
  • each mold was allowed to cool, in a conventional manner, with a protective flux on the surface, so as to form a solid ingot.
  • the ingots were then removed from the molds.
  • Control castings are then used, in an identical manner using argon and carbon dioxide as indicated in the table below.
  • the following example is an ineffective wrapping procedure.
  • Carbon dioxide Due to the relatively low cost of carbon dioxide and its availability compared for example to argon or nitrogen, its non-toxicity with respect to carbon monoxide for example and the fact that this gas can be produced locally and delivered in continuous, make it an extremely useful gas when used as described here. Carbon dioxide is heavier than air (1.3: 1) as compared to argon 1.37: 1 and therefore maintains an effective protective covering longer than lighter gases, since it does not disperse so easily in the atmosphere.
  • the quantity of oxygen in the starting steel, which is poured depends on the quality of the steel and can be between 400 parts per million and 1900 parts per million or, in particular steels or in the case of 'continuous casting, this amount of oxygen can be as low as 40 parts per million. In a normal casting operation, without wrapping, one would expect that the oxygen captured by the steel would be present in a number amounting to hundreds of parts per million by volume.
  • the quantity captured is not more than 700 ppm and can be as low as a value between 20 and 30 ppm.

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Claims (7)

1. Verfahren zum Schützen eines Gußstahl-Gießstrahls, der aus einem oberen Behälter in einen unteren Behälter übertritt, bei welchem Verfahren der Gießstrahl mit einem Kohlendioxid enthaltenden Inertgas umgeben wird, dadurch gekennzeichnet, daß der Inertgasstrom mindestens 50 % Kohlendioxid enthält, wobei der Durchsatz dieses Gasstroms ausreicht, um eine Schranke zwischen dem besagten Strahl und der Umgebungsluft herzustellen, daß der Inertgasstrom während höchstens 0,15 s Kontakt mit dem Gußstahl hat und durch ständigen Umlauf auf einer Temperatur von weniger als 700°C gehalten wird, und daß der Schutzgasstrom so eingespritzt wird, daß sich seine Geschwindigkeit von der Geschwindigkeit des Gießstrahls um mindestens 1,5 m/s unterscheidet, wobei der Partialdruck des Kohlendioxids höchstens 1 at beträgt.
2. Verfahren zum Schützen eines Gußstahl-Gießstrahls, der von einem oberen Behälter in einen unteren Behälter übertritt, bei welchen Verfahren der Gießstrahl von einem Kohlendioxid enthaltenden, schützenden Inertgas umgeben wird, dadurch gekennzeichnet, daß für die Bildung des Schutzgasstroms;
- in gleichmäßigem Zeitabstand aus einem Tank (E), der flüssiges Kohlendioxid enthält, über welchem sich ein eine Gasphase enthaltender freie Raum (33) befindet, eine vorbestimmte Menge Kohlendioxidgas Bus dem freien Raum (33) abgezogen wird,
- aus dem Tank (E) flüssiges Kohlendioxid abgezogen wird, verdampft wird und in den freien Raum (33) des Tanks eingespritzt wird, so daß die im vorhergehenden Schritt aus dem freien Raum abgezogen Menge Kohlendioxid ersetzt wird,
- die vorbestimmte Menge Kohlendioxidgas in eine Heizvorrichtung (F) geleitet wird, um sie auf eine über der Umgebungstemperatur liegende Temperatur zu bringen,
- die besagte vorbestimmte erwärmte Menge durch Regelventile (42, 43) geführt wird und das Gas durch Regleröffnungen (44, 45) hindurch entspannt wird, die den Schutzgasstrom in zur Verwendung geeigneter Menge und bei etwa der Umgebungstemperatur entsprechender Temperatur zuführen.
3. Verfahren nach den Ansprüchen 1 bis 2, dadurch gekennzeichnet, daß das Schutzgas zu mehr als 50 % aus Kohlendioxid besteht und der Rest ein nichtoxidierendes Gas ist.
4. Verfahren nach den Ansprüchen 1 bis 2, dadurch gekennzeichnet, daß das Schutzgas zu 100 % aus Kohlendioxid besteht.
5. Verfahren nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß der untere Behälter zuvor entleert wird, indem die darin vorhandene Luft durch Kohlendioxid ersetzt wird, das in der Kokille eine schützende Hülle bildet.
6. Verfahren zur Ausübung einer Vielzahl von Schutzgasoperationen nacheinander, nach einem der Ansprüche 1 bis 5, wobei das flüssige Metall von einem oberen Behälter in einen unteren Behälter gegossen wird und eine Schutzgashülle um den Gußstahl-Gießstrahl gebildet wird, um diesen gegenüber den Verunreinigungen aus der umgebenden Atmosphäre zu schützen, dadurch gekennzeichnet, daß:
- ein Behälter benutzt wird, der in seinem unteren Teil flüssiges Kohlendioxid und in seinem oberen Teil gasförmiges Kohlendioxid unter einem vorbestimmten Druck enthält,
- nacheinander eine Vielzahl von Schritten für die herbeiführung eines Schutzes mit Schutzgas ausgeübt wird, wobei für jeden Schritt eine vorbestimmte Menge Kohlendioxidgas aus dem oberen Teil des Behälters entnommen wird so daß der Druckin dem Behälter sinkt,
- unmittelbar beim Auftreten der Druckabnahme Flüssigkeit aus dem Behälter abgezogen wird, die in dessen oberen Teil hinein verdampft wird, bis das Druckgleichgewicht wiederhergestellt ist und die durch Einleiten der vorbestimmten Gasmenge verloren gegangene Gasmenge ersetzt ist,
- jede den Behälter verlassende vorbestimmte Menge Kohlendioxidgas über die Umgebungstemperatur hinaus erwärmt wird,
- die so erwärmte vorbestimmte Gasmenge durch eine Reglergruppe (44, 45) geleitet wird, in der der Druck herabgesetzt wird, so daß der vorgesehene Durchsatz von Kohlendioxidgas durch die Steuerventile (48, 49) in die Vorrichtung zum Einleiten von Gas zur Ausführung des jeweiligen Schrittes erzielt wird.
7. Vorrichtung zum Ausführen einer Vielzahl von Schutzgasoperationen nacheinander, nach Anspruch 6, wobei jede Operation das Gießen eines Metallgießstrahls aus einem oberen Behälter (A) in einen unseren Behälter (B) umfaßt und der obere Behälter (A) mit einem System (27) zum Öffnen und Schließen am unteren Teil des Behälters versehen ist, das beim Öffnen den Gußauslauf ermöglicht, dadurch gekennzeichnet, daß sie enthält:
- einen Behälter (E) zur Unterbringung des flüssigen Kohlendioxids im unteren Teil und des gasförmigen Kohlendioxids im oberen Teil des Behälters,
- in oberen Teil des Behälters vorgesehene Rohrleitungen zum Fördern des Kohlendioxids zu der Einrichtung zum Einleiten von Kohlendioxid,
- eine Einrichtung (34) zum Überwachen der Rohrleitungen, in denen das Kohlendioxid in einer vorbestimmten Menge abgezogen wird, welche für jede Schutzgasoperation ausreicht,
- eine Einrichtung (32, 35), mit der flüssiges Kohlendioxid aus dem unteren Teil des Behälters abgezogen, verdampft und in den oberen Teil des Behälters eingeführt wird, um die zuvor entnommene vorbestimmte Menge zu ersetzen,
- eine Einrichtung (46, 48) zum Überwachen des Schutzgasdurchsatzes, damit eine zum Erzeugen der Schutzumhüllung ausreichende Menge des besagten Gases zugeleitet wird,
- eine Einrichtung (F) zum Erwärmen des den Behälter verlassenden Kohlendioxidgases auf eine über der Umgebungstemperatur liegende Temperatur,
- eine Einrichtung (44, 45) zur Druckreduzierung und eine ventilartige Vorrichtung (47, 49) zum Oberwachen des Gasdurchsatzes an der Einrichtung zum Einleiten von Kohlendioxid,
- eine Einrichtung zur Überwachung der Temperatur, auf die das Kohlendioxidgas erwärmt werden ist, so daß die Temperatur des Kohlendioxidgases bei dessen Entspannung zur derstellung der Schutzgasumhüllung auf einen Wert zurückgeführt wird, der nicht unter der Umgebungstemperatur liegt, damit das Kohlendioxid in Gasform eingeleitet wird.
EP86400336A 1985-02-21 1986-02-18 Verfahren zum Schützen eines Stahlgiessstrahls Expired EP0196242B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86400336T ATE42227T1 (de) 1985-02-21 1986-02-18 Verfahren zum schuetzen eines stahlgiessstrahls.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US06/703,751 US4614216A (en) 1984-02-24 1985-02-21 Method of and apparatus for casting metal using carbon dioxide to form gas shield
US703751 1985-02-21
US06/799,587 US4657587A (en) 1985-02-21 1985-11-19 Molten metal casting
US799587 1985-11-19

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EP0196242A1 EP0196242A1 (de) 1986-10-01
EP0196242B1 true EP0196242B1 (de) 1989-04-19

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AU (1) AU582825B2 (de)
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FR2607039B1 (fr) * 1986-11-26 1989-03-31 Air Liquide Procede de coulee d'acier comportant un inertage du bain d'acier par de l'anhydride carbonique sous forme de neige
US4723997A (en) * 1987-04-20 1988-02-09 L'air Liquide Method and apparatus for shielding a stream of liquid metal
US4806156A (en) * 1987-07-24 1989-02-21 Liquid Air Corporation Process for the production of a bath of molten metal or alloys
US4848751A (en) * 1987-07-24 1989-07-18 L'air Liquide Lance for discharging liquid nitrogen or liquid argon into a furnace throughout the production of molten metal
DE3904415C1 (de) * 1989-02-14 1990-04-26 Intracon Handelsgesellschaft Fuer Industriebedarf M.B.H., 6200 Wiesbaden, De
EP0544967B1 (de) * 1991-11-28 1995-06-14 Carbagas Verfahren zur Unterdrückung von Staub und Rauch bei der Elektrostahlherstellung
US5404929A (en) * 1993-05-18 1995-04-11 Liquid Air Corporation Casting of high oxygen-affinity metals and their alloys
US6228187B1 (en) 1998-08-19 2001-05-08 Air Liquide America Corp. Apparatus and methods for generating an artificial atmosphere for the heat treating of materials
US6491863B2 (en) 2000-12-12 2002-12-10 L'air Liquide-Societe' Anonyme A' Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes George Claude Method and apparatus for efficient utilization of a cryogen for inert cover in metals melting furnaces
US20080184848A1 (en) 2006-08-23 2008-08-07 La Sorda Terence D Vapor-Reinforced Expanding Volume of Gas to Minimize the Contamination of Products Treated in a Melting Furnace
US20090064821A1 (en) * 2006-08-23 2009-03-12 Air Liquide Industrial U.S. Lp Vapor-Reinforced Expanding Volume of Gas to Minimize the Contamination of Products Treated in a Melting Furnace
US8403187B2 (en) * 2006-09-27 2013-03-26 Air Liquide Industrial U.S. Lp Production of an inert blanket in a furnace
JPWO2012127793A1 (ja) 2011-03-22 2014-07-24 パナソニック株式会社 弾性波素子
CN107983945B (zh) * 2017-11-08 2019-04-23 马鞍山市万鑫铸造有限公司 金属的连续模型铸造装置

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US347167A (en) * 1886-08-10 Albeet e
FR434070A (fr) * 1910-11-14 1912-01-24 Marcellin Reymondier Nouveau procédé de coulée et de moulage permettant d'obtenir des aciers, fontes, métaux ou alliages sains et homogènes
US1212825A (en) * 1916-04-20 1917-01-16 James E Sheaffer Compound for covering the top of molten metal in ingot-molds.
US1227573A (en) * 1917-04-12 1917-05-29 William A Bole Method of making castings.
US1750751A (en) * 1927-02-04 1930-03-18 Geyer Andre Aluminum alloy
US1978022A (en) * 1930-11-15 1934-10-23 Patent & Licensing Corp Rubber asphalt dispersion
US1978222A (en) * 1932-09-24 1934-10-23 Allegheny Steel Co Method of and apparatus for treating metallic materials
US2092595A (en) * 1935-03-06 1937-09-07 Jr William H Spowers Dry blanket for metal baths
US3174200A (en) * 1961-06-15 1965-03-23 Union Carbide Corp Method of purging mold and pouring metal therein
US3392009A (en) * 1965-10-23 1968-07-09 Union Carbide Corp Method of producing low carbon, non-aging, deep drawing steel
BE677958A (de) * 1966-03-16 1966-09-16
US3451594A (en) * 1966-05-17 1969-06-24 Sigmund W Stewart Tundish nozzle construction
LU70560A1 (de) * 1973-07-24 1974-11-28
US4089678A (en) * 1975-08-01 1978-05-16 Hanawalt Joseph D Method and product for protecting molten magnesium
ZA85911B (en) * 1984-02-24 1985-09-25 Liquid Air Canada Molten metal casting
FR2579495B1 (fr) * 1985-04-01 1987-09-11 Air Liquide Procede de protection d'un jet de coulee de metal

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AU582825B2 (en) 1989-04-13
DE3662844D1 (en) 1989-05-24
US4657587A (en) 1987-04-14
AU5361286A (en) 1986-08-28
EP0196242A1 (de) 1986-10-01

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