EP0917500B1 - Method of producing castings - Google Patents

Method of producing castings Download PDF

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Publication number
EP0917500B1
EP0917500B1 EP97918966A EP97918966A EP0917500B1 EP 0917500 B1 EP0917500 B1 EP 0917500B1 EP 97918966 A EP97918966 A EP 97918966A EP 97918966 A EP97918966 A EP 97918966A EP 0917500 B1 EP0917500 B1 EP 0917500B1
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EP
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Prior art keywords
casting
air
cooling
process according
cooled
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German (de)
French (fr)
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EP0917500A1 (en
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Michael Fenne
Oswald Holtz
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D5/00—Heat treatments of cast-iron
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
    • C21D1/613—Gases; Liquefied or solidified normally gaseous material
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/62—Quenching devices
    • C21D1/667—Quenching devices for spray quenching

Definitions

  • the invention relates to a method for producing castings, like engine blocks u. Like., made of cast iron with lamellar graphite.
  • Castings are used in almost all industries such as for example in machine tool construction, in the manufacture of semi-finished products, in Furnace and heating construction, in engine construction and ultimately also in chemical Industry. To save weight, it is desirable to include the castings sufficient strength to manufacture thin-walled, which is a good one Flowability of the melted cast iron conditionally. It is known that a increased carbon content the fluidity of the cast iron melt favored. The carbon content of the cast iron can be determined by the Control the type or the mode of operation of the furnace. It will Cast iron usually melted in the cupola furnace. However, the Melting process also in a drum furnace or an electric furnace be made. After casting, the casting usually remains until it has cooled to about 300 ° C.
  • the at Structural state achieved in this cooling process is usually accepted, although it is known by certain cooling conditions the structural condition and thus the mechanical properties of the cast iron to influence. It is to achieve certain mechanical properties usual, alloyed cast iron by adding special additives such as for example copper, chromium, phosphorus, antimony, manganese, microalloys etc. to generate.
  • the object of the present invention is to produce castings whose mechanical properties in terms of their hardness and strength corresponding microstructure formation can be influenced in a predetermined manner can.
  • This object is with the features specified in claim 1 solved.
  • This treatment can lead to the addition of alloying substances can be dispensed with for the genus or for the melting of the cast iron, since partial areas of the casting with higher mechanical properties have the specified manner produced, without this generally in the whole Casting would be the case. Accordingly, when editing the Casting only the areas that have higher mechanical properties have a later machining with high quality Tools, while the other areas deal with usual, simple Have tools processed.
  • the partial increase in hardness of the Cast iron is increased by increasing the carbon content to 3 to 4% preferably 3.6 to 3.8% C content balanced, which can be controlled of the melting process via the genus and / or the operation of the Melting furnace and subsequent pouring of the melt in sand or Lost foam process can be achieved.
  • the areas of Casting that is not caused by additional intermittent air blasts in their Hardness has been raised, can be edited in the usual, simple way. Continuously alloyed or continuously increased in hardness Cast iron would increase the processing of the casting as a result Make tool wear more expensive.
  • the casting is advantageous in after the cooling treatment a holding oven to avoid residual stresses gradually low residual temperature.
  • the air blasts that are partially aligned with certain surface areas are dimensioned to produce a hardness of more than 220 HB.
  • the cooling times of both the steady, general air flow and the partial air blasts are preferably dimensioned to maintain a tensile strength of at least 250 N / mm 2 .
  • the amount of cooling air for the constant, general air flow on the one hand and the partial air blasts on the other hand as well as the cooling times can be determined empirically, ie empirically.
  • the cooling treatment of the casting is advantageously controllable and programmable by means of an EDP system comprising a camera and a monitor with regard to the cooling intensity, the permanent air flow and the pulsating, partially adjustable air blasts.
  • the castings to be cooled can preferably be positioned on a continuous conveyor in order to pass through the treatment section which emits a steady air flow and intermittent air blows.
  • a continuous conveyor as a link belt conveyor with plug-in receiving edges for positioning the casting, at least the nozzles that blow off air blows can be adjusted in a controlled manner and can be tracked to the link conveyor in regions with a corresponding speed .
  • Cooling process heated air for heating purposes and / or Use water heating.
  • the heated air is preferred fed to a heat exchanger.
  • this melt is used to produce a casting, which can be an engine block, for example, in a sand casting mold or poured into a lost foam mold.
  • a continuous conveyor 11 may advantageously be a link belt conveyor, on the plates of which the casting is positioned by means of plug-in receiving edges (not shown). As can be seen from the drawing, the plates of the continuous conveyor 11 together with the casting 10 form the casting transport plane 12.
  • strip-shaped cooling air supply funnels 13 extending over a wide length range of the continuous conveyor 11 the casting 10 are directed and blow it with a steady stream of cooling air. Also below the air-permeable plates of the continuous conveyor 11, strip-shaped cooling air supply funnels 14 are arranged in a stationary manner over the same conveying path and also blow the casting 10 at a constant flow of cooling air.
  • the amount of cooling air and the throughput speed of the continuous conveyor 11 are designed such that, starting from the starting temperature of the casting 10, it has cooled to at least 723 ° C. after leaving the cooling section.
  • these targeted, intermittent blasts of compressed air in addition to supporting the cooling of the casting points, remove the mold residues in a certain time unit, so that a uniformly smooth surface of the casting is available for the cooling process and the impact of the cooling air.
  • the moving high-pressure cooling lines 15 and 16 can be controlled by marking the surfaces or parts of the casting 10 to be treated on a screen three-dimensionally depositing the casting to be treated, so that the intensity of the cooling and the intensity of the pulses can be pre-programmed.
  • the stationary cooling air supply funnels 13 together with the traceable high-pressure cooling line 15 form an upper cooling device section 18, while the cooling air supply funnels 14 form a lower cooling device section 19 in connection with the traceable high-pressure cooling line 16. While the permanent supply of cooling air is now operated as low-pressure cooling, the intermittent cooling air supplied to certain points of the casting is operated as high-pressure cooling.
  • a camera recognizes the position of the casting 10 and converts it into electronic data, on the basis of which the nozzles are brought to the locations of the casting determined by the program and one according to the intensity and duration of the high-pressure air flow produce the desired cooling effect so that the treated surfaces of the casting achieve a tensile strength of at least 250 N / mm 2 .
  • a Brinell hardness of more than 220 HB is achieved at the relevant points through the use of these targeted, pulsed cooling air jets.
  • the cooling process is prevented and, in order to eliminate residual stresses in the casting, this is fed to a holding furnace which, together with the residual heat from the casting, causes a re-heating, by means of which the residual stresses in the casting are eliminated.
  • the holding furnace is operated in such a way that the casting is gradually cooled down to about 300 ° C.
  • cooling device is surrounded by a housing 20 and the bottom of the cooling area an opening 21 for disposal of the Has molding sand.
  • Cooling device provided one (or more) dedusting opening 22, the can be connected to a dedusting system.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Continuous Casting (AREA)
  • Mold Materials And Core Materials (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Abstract

In order to produce castings from cast iron with foliated graphite, the carbon content of the cast iron can be set at between approximately 3 and 4% by controlling the melting process of the type and/or operation of the melting furnace. The molten mass is then cast in a sand-casting or lost-form method. During conventional cooling, the known mechanical properties of the cooled cast are set. In order to improve these mechanical properties in terms of hardness and strength, the casting is released from its mold at a temperature ranging from 1,100° C. to 800° C. and is immediately subjected to a cooling treatment by being blasted with an air flow in order to cool it to below 723° C. in a given amount of time. The casting, in selected regions, is cooled to below 723° C. by specific intermittent bursts of air in a relatively short amount of time in order to produce a harder structure. The cooling treatment is stopped when the temperature at the eutectoid line of the iron-carbon diagram is reached.

Description

Die Erfindung bezieht sich auf ein Verfahren zur Herstellung von Gußstücken, wie Motorblöcken u. dgl., aus Gußeisen mit Lamellengraphit.The invention relates to a method for producing castings, like engine blocks u. Like., made of cast iron with lamellar graphite.

Gußstücke finden nahezu in der gesamten Industrie Anwendung wie beispielsweise im Werkzeugmaschinenbau, bei der Halbzeugherstellung, im Ofen- und Heizungsbau, im Motorenbau und letztlich auch in der chemischen Industrie. Zur Gewichtsersparnis ist es wünschenswert, die Gußstücke bei ausreichender Festigkeit dünnwandig herzustellen, was jedoch eine gute Fließfähigkeit des erschmolzenen Gußeisens bedingt. Es ist bekannt, daß ein erhöhter Kohlenstoffgehalt die Fließfähigkeit der Schmelze des Gußeisens begünstigt. Der Kohlenstoffgehalt des Gußeisens läßt sich durch die Gattierung oder auch die Fahrweise des Ofens steuern. Dabei wird das Gußeisen in der Regel im Kupolofen erschmolzen. Allerdings kann der Schmelzvorgang auch in einem Trommelofen oder einem Elektroofen vorgenommen werden. Nach dem Abguß verbleibt das Gußstück üblicherweise solange in seiner Form bis es sich auf etwa 300° C abgekühlt hat. Der bei diesem Abkühlvorgang erzielte Gefügezustand wird in der Regel hingenommen, obschon es bekannt ist durch bestimmte Abkühlbedingungen den Gefügezustand und damit die mechanischen Eigenschaften des Gußeisens zu beeinflussen. Zur Erzielung bestimmter mechanischer Eigenschaften ist es üblich, legiertes Gußeisen durch die Zugabe besonderer Zuschlagstoffe wie beispielsweise Kupfer, Chrom, Phosphor, Antimon, Mangan, Mikrolegierungen usw. zu erzeugen.Castings are used in almost all industries such as for example in machine tool construction, in the manufacture of semi-finished products, in Furnace and heating construction, in engine construction and ultimately also in chemical Industry. To save weight, it is desirable to include the castings sufficient strength to manufacture thin-walled, which is a good one Flowability of the melted cast iron conditionally. It is known that a increased carbon content the fluidity of the cast iron melt favored. The carbon content of the cast iron can be determined by the Control the type or the mode of operation of the furnace. It will Cast iron usually melted in the cupola furnace. However, the Melting process also in a drum furnace or an electric furnace be made. After casting, the casting usually remains until it has cooled to about 300 ° C. The at Structural state achieved in this cooling process is usually accepted, although it is known by certain cooling conditions the structural condition and thus the mechanical properties of the cast iron to influence. It is to achieve certain mechanical properties usual, alloyed cast iron by adding special additives such as for example copper, chromium, phosphorus, antimony, manganese, microalloys etc. to generate.

Bei vielen Gußstücken, wozu insbesondere auch Motorblöcke von Verbrennungsmotoren gehören, ist es wünschenswert, daß verschiedene Bereiche härter sind, als andere Bereiche des Gußstücks oder aber auch höhere Festigkeitswerte aufweisen, als andere Bereiche des gleichen Gußstücks.With many castings, especially engine blocks from Internal combustion engines, it is desirable that various Areas are harder than other areas of the casting or else have higher strength values than other areas of the same Casting.

Aufgabe der vorliegenden Erfindung ist es, Gußstücke zu erzeugen, deren mechanische Eigenschaften hinsichtlich ihrer Härte und Festigkeit durch entsprechende Gefügebildung in vorbestimmter Weise beeinflußt werden können. Diese Aufgabe ist mit den im Anspruch 1 angegebenen Merkmalen gelöst. Durch diese Behandlung kann auf die Zugabe von Legierungsstoffen zur Gattierung oder zur Schmelze des Gußeisens verzichtet werden, da sich partielle Bereiche des Gußstücks mit höheren mechanischen Eigenschaften auf die angegebene Weise herstellen lassen, ohne daß dies generell im gesamten Gußstück der Fall wäre. Demzufolge erfordern bei der Bearbeitung des Gußstückes lediglich die Bereiche, die höhere mechanische Eigenschaften aufweisen eine spätere spanabhebende Bearbeitung mit hochwertigen Werkzeugen, während die anderen Bereiche sich mit üblichen, einfachen Werkzeugen bearbeiten lassen. Die partielle Anhebung der Härte des Gußeisens wird durch die Anhebung des Kohlenstoffgehaltes auf 3 bis 4% vorzugsweise 3,6 bis 3,8% C-Gehalt ausgeglichen, was sich durch Steuerung des Schmelzprozesses über die Gattierung und/oder den Betrieb des Schmelzofens sowie anschließenden Abguß der Schmelze im Sandguß oder Lost-Foam-Verfahren erzielen läßt. Somit können die Bereiche des Gußstücks, die nicht durch zusätzliche intermittierende Luftstöße in ihrer Härte angehoben wurden, auf die übliche, einfache Weise bearbeitet werden. Durchgehend legiertes oder in seiner Härte durchgehend angehobenes Gußeisen würde die Bearbeitung des Gußstückes infolge erhöhten Werkzeugverschleißes verteuern.The object of the present invention is to produce castings whose mechanical properties in terms of their hardness and strength corresponding microstructure formation can be influenced in a predetermined manner can. This object is with the features specified in claim 1 solved. This treatment can lead to the addition of alloying substances can be dispensed with for the genus or for the melting of the cast iron, since partial areas of the casting with higher mechanical properties have the specified manner produced, without this generally in the whole Casting would be the case. Accordingly, when editing the Casting only the areas that have higher mechanical properties have a later machining with high quality Tools, while the other areas deal with usual, simple Have tools processed. The partial increase in hardness of the Cast iron is increased by increasing the carbon content to 3 to 4% preferably 3.6 to 3.8% C content balanced, which can be controlled of the melting process via the genus and / or the operation of the Melting furnace and subsequent pouring of the melt in sand or Lost foam process can be achieved. Thus the areas of Casting that is not caused by additional intermittent air blasts in their Hardness has been raised, can be edited in the usual, simple way. Continuously alloyed or continuously increased in hardness Cast iron would increase the processing of the casting as a result Make tool wear more expensive.

Um innere Spannungen im Gußstück nach der Abkühlbehandlung zu eliminieren, wird das Gußstück vorteilhaft nach der Abkühlbehandlung in einem Warmhalteofen zur Vermeidung von Eigenspannungen schrittweise auf eine geringe Resttemperatur zurückführt.To reduce internal stresses in the casting after the cooling treatment eliminate, the casting is advantageous in after the cooling treatment a holding oven to avoid residual stresses gradually low residual temperature.

Zur Erzielung ausgewählter Härtebereiche des Gußstücks sind die auf bestimmte Flächenbereiche partiell ausgerichteten Luftstöße zur Erzeugung einer Härte von mehr als 220 HB bemessen. Außerdem sind vorzugsweise die Kühlzeiten sowohl des stetigen, allgemeinen Luftstromes als auch der partiellen Luftstöße zur Erhaltung einer Zugfestigkeit von wenigstens 250 N/mm2 bemessen. Die Menge der Kühlluft für den stetigen, allgemeinen Luftstrom einerseits und die auch partiellen Luftstöße andererseits sowie die Kühlzeiten lassen sich aufgrund von Erfahrungswerten, d.h. empirisch bestimmen. Um das Verfahren hinsichtlich seines reproduzierbaren Ergebnisses unter wirtschaftlichen Aspekten zu homogenisieren ist die Abkühlbehandlung des Gußstückes vorteilhaft mittels einer eine Kamera und einen Monitor umfassenden EDV-Anlage hinsichtlich der Kühlungsintensität, des permanenten Luftstromes und der pulsierenden, partiell ausrichtbaren Luftstöße steuerbar und programmierbar. Dazu lassen sich die abzukühlenden Gußstücke vorzugsweise auf einem Stetigförderer positionieren, um die einen stetigen Luftstrom und intermittierende Luftstöße abgebende Behandlungsstrecke zu durchlaufen. Obschon es denkbar ist, die Gußstücke in verschiedener Weise durch die Behandlungsstrecke hindurchzuführen, ist es vorteilhaft einen Stetigförderer als Gliederbandförderer mit steckbar angeordneten Aufnahmekanten zur Positionierung des Gußstückes zu verwenden, wobei zumindest die Luftstöße abblasenden Düsen gesteuert einstellbar und bereichsweise mit übereinstimmender Geschwindigkeit dem Gliederbandförderer nachführbar sind.In order to achieve selected hardness areas of the casting, the air blasts that are partially aligned with certain surface areas are dimensioned to produce a hardness of more than 220 HB. In addition, the cooling times of both the steady, general air flow and the partial air blasts are preferably dimensioned to maintain a tensile strength of at least 250 N / mm 2 . The amount of cooling air for the constant, general air flow on the one hand and the partial air blasts on the other hand as well as the cooling times can be determined empirically, ie empirically. In order to homogenize the process in terms of its reproducible result from an economic point of view, the cooling treatment of the casting is advantageously controllable and programmable by means of an EDP system comprising a camera and a monitor with regard to the cooling intensity, the permanent air flow and the pulsating, partially adjustable air blasts. For this purpose, the castings to be cooled can preferably be positioned on a continuous conveyor in order to pass through the treatment section which emits a steady air flow and intermittent air blows. Although it is conceivable to guide the castings through the treatment section in different ways, it is advantageous to use a continuous conveyor as a link belt conveyor with plug-in receiving edges for positioning the casting, at least the nozzles that blow off air blows can be adjusted in a controlled manner and can be tracked to the link conveyor in regions with a corresponding speed .

Zur Vermeidung von Energieverschwendung ist es vorteilhaft, die beim Kühlvorgang erwärmte Luft zu Heizzwecken und/oder zur Warmwasserbereitung zu nutzen. Dabei wird die erwärmte Luft vorzugsweise einem Wärmetauscher zugeführt.To avoid wasting energy, it is advantageous to use the Cooling process heated air for heating purposes and / or Use water heating. The heated air is preferred fed to a heat exchanger.

Die Erfindung ist anhand eines Ausführungsbeispieles erläutert und in einer das Behandlungsprinzip zeigenden Zeichnung dargestellt.The invention is explained using an exemplary embodiment and in one the treatment principle shown drawing.

Nachdem eine im Kupolofen erzeugte Graugußschmelze mit einem Kohlenstoffgehalt von etwa 3,4 bis 4,0% unter Regulierung des Siliziumgehaltes erzeugt ist, wird diese Schmelze zur Erzeugung eines Gußstücks, bei dem es sich beispielsweise um einen Motorblock handeln kann, in eine Sandguß-Form oder in eine Lost-Foam-Form abgegossen. Nach dem Abguß wird das Gußstück 10 gezielt aus seiner Form getrennt, gelöst oder ausgepackt und auf einem Stetigförderer 11 plaziert Bei diesem Stetigförderer mag es sich vorteilhaft um einen Gliederbandförderer handeln, auf dessen Platten das Gußstück mittels steckbar angeordneter, nicht dargestellter Aufnahmekanten positioniert festgelegt ist. Wie aus der Zeichnung entnommen werden kann, bilden die Platten des Stetigförderers 11 zusammen mit dem Gußstück 10 die Gußstück-Transportebene 12. Oberhalb dieser Gußstück-Transportebene befinden sich über einen weiten Längenbereich des Stetigförderers 11 sich erstreckende, stationär angeordnete leistenförmige Kühlluftzuführungstrichter 13, die auf das Gußstück 10 gerichtet sind und dieses mit einem stetigen Kühlluftstrom anblasen. Auch unterhalb der luftdurchlässigen Platten des Stetigförderers 11 sind leistenförmige Kühlluftzuführungstrichter 14 über die gleiche Förderstrecke stationär angeordnet und blasen ebenfalls mit einem stetigen Kühlluftstrom das Gußstück 10 an. Dabei ist die Kühlluftmenge und die Durchlaufgeschwindigkeit des Stetigförderers 11 derart ausgelegt, daß ausgehend von der Ausgangstemperatur des Gußstückes 10 dieses nach Verlassen der Kühlstrecke auf mindestens 723° C abgekühlt ist. Sowohl im oberen als auch im unteren Bereich des Gußstückes 10 befindet sich eine mit der Transportgeschwindigkeit des Stetigförderers 11 übereinstimmend mitführbare und an das Gußstück 10 anstellbare Hochdruckkühlleitung 15 bzw. 16, mittels welcher über Düsen 17 intermittierende Kühlluftstöße auf bestimmte Stellen des Gußstückes 10 abgegeben werden. Gleichzeitig erfolgt durch diese gezielten, intermittierenden Preßluftstöße außer der unterstützenden Abkühlung der Gußstückstellen in bestimmter Zeiteinheit eine Entfernung der Formreste, so daß für den Kühlvorgang und das Auftreffen der Kühlluft eine gleichmäßig glatte Oberfläche des Gußstückes vorhanden ist. Die mitlaufenden Hochdruckkühlleitungen 15 und 16 lassen sich steuern, indem die zu behandelnden Flächen oder Teile des Gußstückes 10 auf einem das zu behandelnde Gußstück dreidimensional hinterlegenden Bildschirm markiert werden, so daß die Intensität der Kühlung und die Intensität der Impulse vorprogrammiert werden kann. Die stationären Kühlluftzuführungstrichter 13 bilden zusammen mit der nachführbaren Hochdruckkühlleitung 15 einen oberen Kühleinrichtungsabschnitt 18, während die Kühlluftzuführungstrichter 14 in Verbindung mit der nachführbaren Hochdruckkühlleitung 16 einen unteren Kühleinrichtungsabschnitt 19 bilden. Während nun die permanente Kühlluftzufuhr als Niederdruckkühlung gefahren wird, wird die intermittierende, bestimmten Stellen des Gußstücks zugeführte Kühlluft als Hockdruckkühlung gefahren. Sobald das zu behandelnde Gußstück 10 in die Behandlungszone einfährt, erkennt eine Kamera die Lage des Gußstücks 10 und setzt diese in elektronische Daten um, aufgrund welcher die Düsen an die durch das Programm bestimmten Stellen des Gußstückes herangeführt und gemäß der Intensität und Zeitdauer des Hochdruckluftstromes einen gewünschten Abkühleffekt erzeugen, so daß die behandelten Oberflächen des Gußstückes eine Zugfestigkeit von wenigstens 250 N/mm2 erreichen. Außerdem wird durch den Einsatz dieser gezielte, impulsartige Kühlluftstöße abgebenden Düsen eine Brinellhärte an den betreffenden Stellen von mehr als 220 HB erreicht. Nach der Abkühlung des Gußstückes unter die eutektoide Linie wird der Kühlprozeß unterbunden und zur Behebung von Eigenspannungen im Gußstück dieses einem Warmhalteofen zugeführt, der zusammen mit der Restwärme aus dem Gußstück wieder eine Rückheizung bewirkt, durch welche die Eigenspannungen im Gußstück beseitigt werden. Dabei wird der Warmhalteofen so gefahren, daß eine schrittweise Abkühlung des Gußstückes bis auf etwa 300° C erfolgt.After a gray cast iron melt produced in the cupola furnace with a carbon content of about 3.4 to 4.0% is produced while regulating the silicon content, this melt is used to produce a casting, which can be an engine block, for example, in a sand casting mold or poured into a lost foam mold. After the casting, the casting 10 is deliberately separated from its shape, released or unpacked and placed on a continuous conveyor 11. This continuous conveyor may advantageously be a link belt conveyor, on the plates of which the casting is positioned by means of plug-in receiving edges (not shown). As can be seen from the drawing, the plates of the continuous conveyor 11 together with the casting 10 form the casting transport plane 12. Above this casting transport plane there are stationary, strip-shaped cooling air supply funnels 13 extending over a wide length range of the continuous conveyor 11 the casting 10 are directed and blow it with a steady stream of cooling air. Also below the air-permeable plates of the continuous conveyor 11, strip-shaped cooling air supply funnels 14 are arranged in a stationary manner over the same conveying path and also blow the casting 10 at a constant flow of cooling air. The amount of cooling air and the throughput speed of the continuous conveyor 11 are designed such that, starting from the starting temperature of the casting 10, it has cooled to at least 723 ° C. after leaving the cooling section. Both in the upper and in the lower area of the casting 10 there is a high-pressure cooling line 15 or 16, which can be carried along with the transport speed of the continuous conveyor 11 and can be adjusted to the casting 10, by means of which intermittent bursts of cooling air are emitted to certain locations on the casting 10 via nozzles 17. At the same time, these targeted, intermittent blasts of compressed air, in addition to supporting the cooling of the casting points, remove the mold residues in a certain time unit, so that a uniformly smooth surface of the casting is available for the cooling process and the impact of the cooling air. The moving high-pressure cooling lines 15 and 16 can be controlled by marking the surfaces or parts of the casting 10 to be treated on a screen three-dimensionally depositing the casting to be treated, so that the intensity of the cooling and the intensity of the pulses can be pre-programmed. The stationary cooling air supply funnels 13 together with the traceable high-pressure cooling line 15 form an upper cooling device section 18, while the cooling air supply funnels 14 form a lower cooling device section 19 in connection with the traceable high-pressure cooling line 16. While the permanent supply of cooling air is now operated as low-pressure cooling, the intermittent cooling air supplied to certain points of the casting is operated as high-pressure cooling. As soon as the casting 10 to be treated enters the treatment zone, a camera recognizes the position of the casting 10 and converts it into electronic data, on the basis of which the nozzles are brought to the locations of the casting determined by the program and one according to the intensity and duration of the high-pressure air flow produce the desired cooling effect so that the treated surfaces of the casting achieve a tensile strength of at least 250 N / mm 2 . In addition, a Brinell hardness of more than 220 HB is achieved at the relevant points through the use of these targeted, pulsed cooling air jets. After the casting has cooled below the eutectoid line, the cooling process is prevented and, in order to eliminate residual stresses in the casting, this is fed to a holding furnace which, together with the residual heat from the casting, causes a re-heating, by means of which the residual stresses in the casting are eliminated. The holding furnace is operated in such a way that the casting is gradually cooled down to about 300 ° C.

Es versteht sich, daß die Kühleinrichtung mit einem Gehäuse 20 umgeben ist und der Boden des Kühlbereiches eine Öffnung 21 zur Entsorgung des Formsandes aufweist. Außerdem ist in der Behandlungszone der Kühleinrichtung eine (oder mehrere) Entstaubungsöffnung 22 vorgesehen, die an eine Entstaubungsanlage anschließbar ist.It is understood that the cooling device is surrounded by a housing 20 and the bottom of the cooling area an opening 21 for disposal of the Has molding sand. In addition, in the treatment zone Cooling device provided one (or more) dedusting opening 22, the can be connected to a dedusting system.

Das vorbeschriebene Ausführungsbeispiel erläutert das Verfahren nur beispielsweise und läßt sich entsprechend den Bedürfnissen im Rahmen der Ansprüche modifizieren. The above-described embodiment only explains the method for example and can be modified according to the needs within the scope of the claims.

Bezugszeichenliste :Reference symbol list:

1010th
GußstückCasting
1111
StetigfördererContinuous conveyor
1212th
Gußstück-TransportebeneCasting transport level
1313
KühlluftzuführungstrichterCooling air supply funnel
1414
KühlluftzuführungstrichterCooling air supply funnel
1515
HochdruckkühlleitungHigh pressure cooling line
1616
HochdruckkühlleitungHigh pressure cooling line
1717th
Düsejet
1818th
Kühleinrichtungsabschnitt, obenCooler section, above
1919th
Kühleinrichtungsabschnitt, untenCooler section, below
2020th
Gehäusecasing
2121
Öffnungopening
2222
EntstaubungsöffnungDedusting opening

Claims (9)

  1. Process for the production of castings such as engine blocks, etc., from cast iron with lamellar graphite, where the carbon content of the cast iron is adjusted to approximately 3-4% carbon in the melt by control of the melting process through adjustments to the charge make-up and/or to the operation of the melting furnace;
    where the melt is then poured into a mold in the sand-casting or lost-form method;
    where the casting is removed from the mold at a temperature in the range of 1.100-800°
    and subjected immediately afterward to a cooling treatment by a stream of air to remove all traces of mold material from the casting;
    where selected areas of the casting are cooled to a point below the eutectoid range by short, aimed, intermittent blasts of air for obtaining improved mechanical properties; and
    where the cooling treatment is stopped after the temperature falls below the temperature of the eutectoid range.
  2. Process according to Claim 1, characterized in that, after the cooling treatment, the casting is reheated in a holding furnace and then cooled in steps to a low internal temperature to avoid residual stresses.
  3. Process according to Claim 1 or Claim 2, characterized in that the separate air blasts directed onto certain areas of the surface are calculated so as to produce a hardness of more than 220 HB.
  4. Process according to one of the preceding claims, characterized in that the cooling times of both the continuous general air stream and the separate air blasts are calculated so as to obtain a tensile strength of at least 250 N/mm2.
  5. Process according to one of the preceding claims, characterized in that an EDP system including a camera and a monitor controls and programs the cooling treatment of the casting with respect to the cooling intensity of the continuous air stream and the intensity of the pulsating, aimable, separate air blasts.
  6. Process according to one of the preceding claims, characterized in that the castings to be cooled are positioned on a continuous conveyor and pass through a treatment section where they are subjected to an air stream and to air blasts.
  7. Process according to Claim 5, characterized in that an apron conveyor with insertable retaining edges for holding the castings in position is used as the continuous conveyor; in that at least the settings of the nozzles delivering the air blasts can be controlled; and in that the nozzles can travel along certain distances at the same rate of speed as the apron conveyor.
  8. Process according to one of the preceding claims, characterized in that the air which has been heated by the cooling process is used for heating purposes and/or for the preparation of hot water.
  9. Process according to Claim 8, characterized in that the heated air is sent to a heat exchanger.
EP97918966A 1996-08-09 1997-08-06 Method of producing castings Expired - Lifetime EP0917500B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19632195 1996-08-09
DE19632195A DE19632195C1 (en) 1996-08-09 1996-08-09 Process for the production of castings
PCT/EP1997/004296 WO1998006524A1 (en) 1996-08-09 1997-08-06 Method of producing castings

Publications (2)

Publication Number Publication Date
EP0917500A1 EP0917500A1 (en) 1999-05-26
EP0917500B1 true EP0917500B1 (en) 2000-05-10

Family

ID=7802246

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97918966A Expired - Lifetime EP0917500B1 (en) 1996-08-09 1997-08-06 Method of producing castings

Country Status (6)

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US (1) US6199618B1 (en)
EP (1) EP0917500B1 (en)
AT (1) ATE192680T1 (en)
DE (1) DE19632195C1 (en)
ES (1) ES2145595T3 (en)
WO (1) WO1998006524A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6443214B1 (en) 1999-12-07 2002-09-03 Honda Giken Kogyo Kabushiki Kaisha Method for heat treating mold cast product
CL2008002676A1 (en) * 2007-09-10 2010-01-04 Weir Minerals Australia Ltd Method for the production of a cast piece, which comprises emptying the molten material into a mold to form the piece, allowing the molten material to solidify; remove the mold at least partially from the cast and place the cast in a chamber that completely surrounds it, an apparatus and cast.
JP2009184776A (en) * 2008-02-06 2009-08-20 Murata Mach Ltd Automated warehouse and method for supplying clean air to automated warehouse
DE102009041162A1 (en) * 2009-09-11 2011-03-24 Bayerische Motoren Werke Aktiengesellschaft Method for producing cast part such as cylinder head or a crankcase of internal combustion engine, by providing cast form produced from vaporizable material and sand and filling the cast form with liquid casting materials
EP2462913A1 (en) 2010-12-10 2012-06-13 Fresenius Medical Care Deutschland GmbH Insert and vial for the infusion of liquids
CN109014140B (en) * 2018-08-02 2020-05-15 繁昌县长城铸造厂（普通合伙） Quick cooling device that foundry goods was used
CN114247851B (en) * 2021-12-13 2023-09-26 广西大学 Pouring and cooling integrated device for gray cast iron production and application thereof

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB342334A (en) * 1929-10-28 1931-01-28 Midland Motor Cylinder Company An improved manufacture of cast iron alloy articles
US2019480A (en) * 1932-10-24 1935-11-05 Campbell Wyant & Cannon Co Method of hardening iron castings
DE2461293B2 (en) * 1974-12-23 1977-12-08 Hilgeroth, Erich, 5630 Remscheid METHOD OF COOLING CASTINGS
DE3442130A1 (en) * 1984-11-17 1986-05-22 Thyssen Industrie Ag, 4300 Essen Process for surface-hardening into the bainite zone of castings of ductile iron-carbon casting materials
DE3605153A1 (en) * 1986-02-18 1987-08-20 Mtu Muenchen Gmbh DEVICE FOR DIFFERENT COOLING OR TEMPERATURE INSIDE AND OUTSIDE OR WALL AREAS OF A COMPONENT, IN PARTICULAR A TURBO MACHINE PART
JPS63241112A (en) * 1987-03-27 1988-10-06 Kawasaki Steel Corp Local cooling apparatus
US4990194A (en) * 1988-09-09 1991-02-05 Hitachi Metals, Ltd. Thin high-strength article of spheroidal graphite cast iron and method of producing same
JP3012380B2 (en) * 1991-10-11 2000-02-21 本田技研工業株式会社 Method and apparatus for forming chill layer
DE4135313A1 (en) * 1991-10-25 1993-04-29 Ipsen Ind Int Gmbh METHOD FOR COOLING A WORKING PIECE BATCH WITHIN A HEAT TREATMENT PROCESS

Also Published As

Publication number Publication date
ATE192680T1 (en) 2000-05-15
DE19632195C1 (en) 1998-03-05
US6199618B1 (en) 2001-03-13
WO1998006524A1 (en) 1998-02-19
ES2145595T3 (en) 2000-07-01
EP0917500A1 (en) 1999-05-26

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