EP0829554B1 - Low pressure carburising device with a plurality of sequentially arranged chambers - Google Patents
Low pressure carburising device with a plurality of sequentially arranged chambers Download PDFInfo
- Publication number
- EP0829554B1 EP0829554B1 EP19970890166 EP97890166A EP0829554B1 EP 0829554 B1 EP0829554 B1 EP 0829554B1 EP 19970890166 EP19970890166 EP 19970890166 EP 97890166 A EP97890166 A EP 97890166A EP 0829554 B1 EP0829554 B1 EP 0829554B1
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- EP
- European Patent Office
- Prior art keywords
- plant according
- chamber
- gas
- pressure
- carbonisation
- 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
Links
- 239000007789 gas Substances 0.000 claims description 24
- 238000010438 heat treatment Methods 0.000 claims description 22
- 238000010791 quenching Methods 0.000 claims description 18
- 230000000171 quenching effect Effects 0.000 claims description 14
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 11
- 238000009792 diffusion process Methods 0.000 claims description 11
- 230000033001 locomotion Effects 0.000 claims description 7
- 238000009413 insulation Methods 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 5
- 238000003763 carbonization Methods 0.000 claims description 5
- 239000000112 cooling gas Substances 0.000 claims description 5
- 229910002804 graphite Inorganic materials 0.000 claims description 5
- 239000010439 graphite Substances 0.000 claims description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims description 5
- 210000000056 organ Anatomy 0.000 claims description 4
- 238000005452 bending Methods 0.000 claims description 3
- 239000000919 ceramic Substances 0.000 claims description 3
- 238000009434 installation Methods 0.000 claims 3
- 230000005540 biological transmission Effects 0.000 claims 1
- 239000007858 starting material Substances 0.000 claims 1
- 238000005255 carburizing Methods 0.000 description 25
- 238000001816 cooling Methods 0.000 description 7
- 238000011282 treatment Methods 0.000 description 5
- 238000000137 annealing Methods 0.000 description 3
- 238000005496 tempering Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/20—Carburising
-
- 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
- C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
- C21D1/773—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material under reduced pressure or vacuum
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/20—Carburising
- C23C8/22—Carburising of ferrous surfaces
Definitions
- the invention relates to a low-pressure carburizing plant several successively arranged chambers through which the batches can be Transport organs are moved.
- Continuous roller hearth furnaces are also known, in which one Gas cooling section is provided between an annealing and a hardening zone (DE 42 28 006).
- the combination according to the invention is compared to conventional Gas carburizing plants achieved a carburization free of edge oxidation, whereby Post-processing costs can be reduced or even eliminated. Moreover the carburizing time is reduced due to a significantly higher C mass flow at the start of the process, which saves time and money. Compared to oil quenching, there is the advantage that a reduced Delay occurs and that both the washing process after the oil quench as there is also no oil disposal.
- the formation of the transport organs as a roller conveyor brings about other transport systems a lower mechanical effort and thus less susceptibility to repairs and also less mechanical Vibrations during transportation of the hot batch.
- a reversal of the batch through roll movement in the area of Quench chamber is when cooling with liquid media and 2-phase flows (DE 44 01 228) is already known and can also be used for gases to improve the uniformity of deterrence.
- the cross-sectional area covered by the cooling gas is, by reversing the batch must be increased, which is at a cost the gas velocity or the cooling rate at a given, maximum Engine power goes.
- This disadvantage is avoided according to the invention in that a movable gas control system installed in the quenching chamber and shared is moved with the batch, whereby the flow of gas flows Cross-section always corresponds to the batch area.
- the drive of the Gas control system is preferably an electromotive Roller drive with the help of a translation.
- roller conveyor Another disadvantage of the roller conveyor can arise from the fact that the rollers are carried out according to the prior art through the insulation, stored outside the insulation and driven outside the boiler, which leads to a not negligible heat dissipation through heat conduction over the Transport roles leads. On the one hand, this causes a higher energy requirement System and on the other hand deteriorates the temperature uniformity in the Treatment chambers.
- the transport rollers According to the invention held by ceramic or graphite bearings, which are within the hot heating, carburizing and diffusion chamber are located on the the underlying insulation.
- the implementation to the transport engine is only carried out with a thin drive shaft that does not transmit any bending moment got to. These measures minimize energy losses.
- the transport rollers in the Heating, carburizing and diffusion zone can be designed as a hollow cylinder, in which introduced an electric beam element or a gas burner and by means of Flange is flanged, reducing the total number Reduced feedthroughs in the heating, carburizing and diffusion chambers becomes.
- the quenching chamber is expedient followed by a Röllchenherd tempering furnace.
- FIG. 1 shows an elevation according to the invention in elevation Low pressure carburizing plant
- Fig. 2 is a top view of the low pressure carburizing plant 1
- FIGS. 3 and 4 cross sections of a Quench chamber usable within the scope of the invention.
- Figures 5,6 and 7 give Variants of the transport rollers again.
- a loading roller table 1 is in front of the system arranged. From this loading roller table 1, the batches 4 enter one Entry lock 6, which is vacuum-tight and can be evacuated. To the Lock 6 connects a likewise evacuable heating chamber 7. In this Heating chamber 7, the batches under nitrogen at a pressure of 1 to 2 bar heated. The heating chamber 7 is with vacuum-tight inlet and Provide outlet doors, batches 4 are heated with circulators 8 and an electric coil heater 9.
- Carburizing chambers 10 and 11 Following the heating chamber 7 are two separate ones Carburizing chambers 10 and 11 arranged. In these carburizing chambers 10 and 11 is abs at a pressure of 0.1 to 60kPa. (1 to 600 mbar abs.), Preferably in the range from 1 to 3 kPa abs. (10 to 30 mbar abs.) Carburized with carburizing gas.
- the arrangement of two separate carburizing chambers allows different parameters for the Beginning and end of carburization and an increase in throughput. However, the arrangement of only one is also within the scope of the invention Carburizing chamber possible. In both carburizing chambers 10 and 11 heating with jacket pipes 12.
- the batches 4 enter a quenching chamber 17 for one High pressure gas quenching.
- the structure of the quench chamber 17 is shown of Fig. 3 explained.
- the batches 4 After leaving the quenching chamber 17, the batches 4 pass over a transverse drive device 18 to a Röllchenherd tempering furnace 19 and leave after passing through a cooling section 20 and an outlet roller table 21, the system.
- the transport of the batches 4 through the plant according to the invention is how 1 is carried out by a roller conveyor 22 which a slow, horizontal pendulum movement of the batch during heating, Carburization and deterrence to even out the treatment outcome enables.
- a preferred embodiment of the quenching chamber 17 is shown in section in FIG. 3 shown.
- a motor 32 is placed on a housing 31, which drives a fan wheel 33.
- a fan wheel 33 Within the lower part 34 one in the housing Batch 4 lies on the 31 round or square jacket Transport rollers 22.
- the jacket expands upwards and inside the extended part 37, a heat exchanger 38 is arranged. This heat exchanger However, 38 does not take up the entire space within part 37 of the shell so that a free cross section 39 is formed.
- the fan wheel 33 promotes nitrogen gas in the sense of the arrows outside of the jacket 34, 37 down, where it is deflected by 90 ° and after above cooling the batch 4 sweeps past it. Subsequently the cooling gas flows partly through the heat exchanger 38, partly through the free one Cross-section 39, the two flows before entering the fan wheel Reunite 33.
- the transport rollers 22 of the quenching chamber 17 allow one Reverse the batch by means of a horizontal pendulum movement, thereby reducing the Uniformity of deterrence can be improved.
- the one in the batch room located, movable gas guide 35 limits the cooling gas coated area largely on the batch base area and leads the free Cross section with the batch with. This prevents the cooling gas alternately flows in front of and behind the batch, if this during the Cooling is reversibly reversed.
- the movement of the gas guide device can preferably done via the roller drive.
- Other solutions, such as the Displacement using pneumatic cylinders is also possible.
- a control valve 41 can be installed, which uses the pressure difference between bypass and immediately behind the heat exchanger on level 2 is controlled in such a way that the cooling time of the batch is minimized.
- the measured flap can be used to determine the optimal flap position Evaluation unit (computer) can be connected.
- FIG. 5 A preferred embodiment of the transport rollers is shown in FIG. 5.
- the transport rollers 22 are here according to the invention by ceramic or Graphite bearing 42 held within the hot heating, carburizing and Diffusion chamber 43 are located on the underlying insulation 44th lie on.
- Several transport rollers are driven outside by means of a chain drive connected to the heating chamber.
- FIG. 7 Another embodiment variant is shown in FIG. 7. Then you can Transport rollers in the heating, carburizing and diffusion zone as a hollow Cylinder 47 can be designed in which an electric heating element or gas burner is introduced and which are flanged by means of a rotary union 48. As a result, the total number of bushings in the heating, Carburizing and diffusion chambers reduced.
- the quenching chamber 17 can be designed with lowerable transport rollers, the place the batch on a fixed batch carrier, the number of Carburizing chambers could be two and the number of diffusion chambers could be three deviate.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
- Tunnel Furnaces (AREA)
Description
Die Erfindung bezieht sich auf eine Niederdruck-Aufkohlungsanlage mit mehreren hintereinander angeordneten Kammern, durch die die Chargen mittels Transportorganen bewegt werden.The invention relates to a low-pressure carburizing plant several successively arranged chambers through which the batches can be Transport organs are moved.
Es sind schon eine Vielzahl von Anlagen zum Wärmebehandeln von aus Stahl bestehenden Teilen bekannt geworden. So ist ein Rollenherd-Vakuumofen bekannt, in dem Glühbehandlungen durchgeführt werden können, wobei ein Hubsystem vorgesehen ist, um die Rollen bei der Glühbehandlung zu entlasten (DE 36 16 871).There are already a number of plants for heat treatment from Steel parts became known. So is a roller hearth vacuum oven known in which annealing treatments can be carried out, with a Lifting system is provided to relieve the rollers during the annealing treatment (DE 36 16 871).
Auch Rollenherd-Durchlauföfen sind schon bekannt, bei denen eine
Gasabkühlstrecke zwischen einer Glüh- und einer Härtezone vorgesehen ist (DE 42
28 006). Ebenso sind Aufkohlungsanlagen, bei denen die Aufkohlung im Bereich
von 0.1-60 kPa abs. (1 - 600 mbar abs.) vorgenommen wird, schon bekannt geworden.Continuous roller hearth furnaces are also known, in which one
Gas cooling section is provided between an annealing and a hardening zone (
Diese Anlagen waren jedoch vorwiegend als Einkammeranlagen für chargenweisen Betrieb ausgeführt. Für größere Durchsatzmengen, die von einigen Industriebereichen, wie z.B. der KFZ-Industrie, benötigt werden, wäre eine Vielzahl solcher Einzelanlagen erforderlich, die neben sehr großem Platzbedarf auch hohe Behandlungskosten verursachen, da sie mit geringer Durchsatzleistung und somit wenig wirtschaftlich arbeiten.However, these systems were primarily used as single-chamber systems batch operation. For larger throughputs by some Industrial areas, such as the automotive industry, would be needed A large number of such individual systems is required, which in addition to a very large space requirement also cause high treatment costs because they have low throughput and therefore work less economically.
Die Erfindung hat es sich zum Ziel gesetzt, eine Niederdruck-Aufkohlungsanlage der eingangs erwähnten Art zu schaffen, die für wirtschaftlichen Betrieb bei großer Durchsatzleistung konzipiert ist und nach dem Durchlaufprinzip arbeitet. Erreicht wird dies durch die Kombination folgender, an sich bekannter Merkmale:
- die Transportorgane sind als Rollenbahn ausgebildet, die die Chargen nacheinander führt durch
- eine vakuumdichte Einfahrschleuse,
- eine evakuierbare Aufheizkammer, in der die Chargen unter Stickstoff bei 100 bis 200 kPa (1 bis 2 bar) aufgeheizt werden,
- wenigstens eine Aufkohlungskammer, in der bei einem Druck von .0.1 bis 60kPa abs. (1 bis 600 mbar abs.), vorzugsweise 1 bis 3 kPa abs. (10 bis 30 mbar abs.), mit Kohlungsgas aufgekohlt wird,
- mindestens eine Diffusionskammer und
- eine Abschreckkammer für eine Hochdruck- Gasabschreckung.
- the transport elements are designed as roller conveyors which carry out the batches one after the other
- a vacuum-tight entrance lock,
- an evacuable heating chamber in which the batches are heated under nitrogen at 100 to 200 kPa (1 to 2 bar),
- at least one carburizing chamber, in which at a pressure of .0.1 to 60kPa abs. (1 to 600 mbar abs.), Preferably 1 to 3 kPa abs. (10 to 30 mbar abs.), Is carburized with carburizing gas,
- at least one diffusion chamber and
- a quenching chamber for high pressure gas quenching.
Durch die erfindungsgemäße Kombination wird gegenüber konventionellen Gasaufkohlungsanlagen eine randoxidationsfreie Aufkohlung erreicht, wodurch Nachbearbeitungskosten verringert werden bzw. sogar wegfallen können. Überdies ergibt sich eine verkürzte Aufkohlungsdauer durch einen erheblich höheren C-Massenstrom zu Prozeßbeginn, was eine Zeit- und Kosteneinsparung zur Folge hat. Gegenüber einer Ölabschreckung ergibt sich der Vorteil, daß ein verminderter Verzug auftritt und daß sowohl der Waschprozeß nach der Ölabschreckung als auch die Ölentsorgung entfällt.The combination according to the invention is compared to conventional Gas carburizing plants achieved a carburization free of edge oxidation, whereby Post-processing costs can be reduced or even eliminated. Moreover the carburizing time is reduced due to a significantly higher C mass flow at the start of the process, which saves time and money. Compared to oil quenching, there is the advantage that a reduced Delay occurs and that both the washing process after the oil quench as there is also no oil disposal.
Die Ausbildung der Transportorgane als Rollenbahn bringt gegenüber anderen Transportsystemen einen geringeren mechanischen Aufwand und damit eine geringere Reparaturanfälligkeit und auch geringere mechanische Erschütterungen beim Transport der heißen Charge mit sich.The formation of the transport organs as a roller conveyor brings about other transport systems a lower mechanical effort and thus less susceptibility to repairs and also less mechanical Vibrations during transportation of the hot batch.
Eine Reversierung der Charge durch Rollenbewegung im Bereich der
Abschreckkammer ist bei Abkühlung mit flüssigen Medien und 2-Phasenströmungen
(DE 44 01 228) bereits bekannt und kann auch für Gase angewendet
werden, um die Gleichmäßigkeit der Abschreckung zu verbessern. Nachteilig
erweist sich jedoch, daß die Querschnittsfläche, die von dem Kühlgas bestrichen
wird, durch das Reversieren der Charge vergrößert werden muß, was auf Kosten
der Gasgeschwindigkeit bzw. der Abkühlrate bei vorgegebener, maximaler
Motorleistung geht. Dieser Nachteil wird erfindungsgemäß dadurch vermieden, daß
ein bewegliches Gasleitsystem in der Abschreckkammer installiert und gemeinsam
mit der Charge bewegt wird, wodurch der von dem Gasstrom beströmte
Querschnitt stets der Chargengrundfläche entspricht. Der Antrieb des
Gasleitsystems erfolgt dabei bevorzugt über einen elektromotorischen
Rollenantrieb mit Hilfe einer Übersetzung. A reversal of the batch through roll movement in the area of
Quench chamber is when cooling with liquid media and 2-phase flows
(
Ein weiterer Nachteil des Rollengangs kann sich aus der Tatsache ergeben, daß die Rollen gemäß dem Stand der Technik durch die Isolation durchgeführt, außerhalb der Isolation gelagert und außerhalb des Kessels angetrieben werden, was zu einer nicht vernachlässigbaren Wärmeabfuhr durch Wärmeleitung über die Transportrollen führt. Dies bewirkt einerseits einen höheren Energiebedarf der Anlage und verschlechtert andererseits die Temperaturgleichmäßigkeit in den Behandlungskammern.Another disadvantage of the roller conveyor can arise from the fact that the rollers are carried out according to the prior art through the insulation, stored outside the insulation and driven outside the boiler, which leads to a not negligible heat dissipation through heat conduction over the Transport roles leads. On the one hand, this causes a higher energy requirement System and on the other hand deteriorates the temperature uniformity in the Treatment chambers.
Um diesen Nachteil zu vermeiden, werden die Transportrollen erfindungsgemäß durch Keramik- oder Grafitlager gehalten, die sich innerhalb der heißen Aufheiz-, Aufkohlungs- und Diffusionskammer befinden und die auf der darunterliegenden Isolation aufliegen. Die Durchführung zum Transportmotor erfolgt nur noch mit einer dünnen Antriebswelle, die kein Biegemoment übertragen muß. Durch diese Maßnahmen werden die Energieverluste minimiert.To avoid this disadvantage, the transport rollers According to the invention held by ceramic or graphite bearings, which are within the hot heating, carburizing and diffusion chamber are located on the the underlying insulation. The implementation to the transport engine is only carried out with a thin drive shaft that does not transmit any bending moment got to. These measures minimize energy losses.
In einer anderen Ausführungsvariante können die Transportrollen in der Aufheiz-, Aufkohlungs- und Diffusionszone als hohle Zylinder ausgeführt sein, in die ein Elektrostrahlelement oder ein Gasbrenner eingebracht und mittels Drehdurchführung angeflanscht wird, wodurch die gesamte Anzahl an Durchführungen in die Aufheiz-, Aufkohlungs- und Diffusionskammern verringert wird.In another embodiment variant, the transport rollers in the Heating, carburizing and diffusion zone can be designed as a hollow cylinder, in which introduced an electric beam element or a gas burner and by means of Flange is flanged, reducing the total number Reduced feedthroughs in the heating, carburizing and diffusion chambers becomes.
Bei einer erfindungsgemäßen Anlage ist zweckmäßig der Abschreckkammer ein Röllchenherd-Anlaßofen nachgeschaltet.In a system according to the invention, the quenching chamber is expedient followed by a Röllchenherd tempering furnace.
Vorteilhaft sind zwei getrennte Aufkohlungskammern hintereinander angeordnet. Diese Trennung ermöglicht unterschiedliche Parameter für den Anfang und das Ende der Aufkohlung, sowie eine Erhöhung der Durchsatzleistung.Two separate carburizing chambers one behind the other are advantageous arranged. This separation allows different parameters to start with and the end of carburization, as well as an increase in throughput.
Die Beheizung von Niederdruck-Aufkohlungsanlagen erfolgt in der Regel mit innenliegenden Grafit-Widerstandsheizelementen, wobei die Isolation der Stromdurchführung durch Abscheidungen des Kohlungsgases (Grafit) fallweise leitend wird und getauscht werden muß, bevor Überschläge der Heizung auftreten. Diese Nachteile werden erfindungsgemäß dadurch beseitigt, daß die Beheizung mittels Mantel-Strahlrohren, bevorzugt mittels Elektro- oder Gasstrahlrohren erfolgt, wobei die Heizelemente bzw. Brenner bei laufendem Betrieb gewechselt werden können.Low-pressure carburizing plants are usually heated with internal graphite resistance heating elements, the insulation of the Conducting electricity by separating the carbonization gas (graphite) from case to case becomes conductive and must be replaced before the heating flashover occurs. According to the invention, these disadvantages are eliminated in that the heating by means of jacket jet pipes, preferably by means of electric or gas jet pipes takes place, with the heating elements or burners being changed during operation can be.
Nachstehend ist die Erfindung anhand eines in den Zeichnungen schematisch
dargestellten Ausführungsbeispieles näher beschrieben, ohne jedoch auf dieses
Beispiel beschränkt zu sein. Dabei zeigen: Fig. 1 im Aufriß eine erfindungsgemäße
Niederdruck-Aufkohlungsanlage; Fig. 2 die Draufsicht auf die Niederdruck-Aufkohlungsanlage
nach Fig. 1 und die Fig. 3 und 4 Querschnitte einer im
Rahmen der Erfindung einsetzbaren Abschreckkammer. Die Fig. 5,6 und 7 geben
Ausführungsvarianten der Transportrollen wieder.The invention is shown schematically below with reference to one of the drawings
illustrated embodiment described in detail, but without this
Example to be limited. 1 shows an elevation according to the invention in elevation
Low pressure carburizing plant; Fig. 2 is a top view of the low
Gemäß den Fig. 1 und 2 ist vor der Anlage ein Beladerollgang 1
angeordnet. Von diesem Beladerollgang 1 gelangen die Chargen 4 in eine
Einfahrschleuse 6, die vakuumdicht ausgebildet und evakuierbar ist. An die
Schleuse 6 schließt eine ebenfalls evakuierbare Aufheizkammer 7 an. In dieser
Aufheizkammer 7 werden die Chargen unter Stickstoff bei einem Druck von 1 bis
2 bar aufgeheizt. Die Aufheizkammer 7 ist mit vakuumdichten Ein- und
Auslauftüren versehen, die Aufheizung der Chargen 4 erfolgt mit Umwälzern 8 und
einer elektrischen Wendelbeheizung 9.1 and 2, a loading roller table 1 is in front of the system
arranged. From this loading roller table 1, the
Anschließend an die Aufheizkammer 7 sind zwei voneinander getrennte
Aufkohlungskammern 10 und 11 angeordnet. In diesen Aufkohlungskammern 10
und 11 wird bei einem Druck von 0.1 bis 60kPa abs. (1 bis 600 mbar abs.), vorzugsweise im Bereich
von 1 bis 3 kPa abs. (10 bis 30 mbar abs.) mit Kohlungsgas aufgekohlt. Die Anordnung von zwei
getrennten Aufkohlungskammern ermöglicht unterschiedliche Parameter für den
Anfang und das Ende der Aufkohlung sowie eine Erhöhung der Durchsatzleistung.
Im Rahmen der Erfindung ist jedoch auch die Anordnung von nur einer
Aufkohlungskammer möglich. In beiden Aufkohlungskammern 10 und 11 erfolgt
die Beheizung mit Mantelstrahlrohren 12.Following the
Auch in den anschließenden Diffusionskammern 13 und 14 erfolgt die
Beheizung mittels Strahlrohren 16.This also takes place in the
Schließlich gelangen die Chargen 4 in eine Abschreckkammer 17 für eine
Hochdruck-Gasabschreckung. Der Aufbau der Abschreckkammer 17 wird anhand
der Fig. 3. noch erläutert. Finally, the
Nach dem Verlassen der Abschreckkammer 17 gelangen die Chargen 4 über
eine Querfahreinrichtung 18 zu einem Röllchenherd-Anlaßofen 19 und verlassen
nach Durchlaufen einer Kühlstrecke 20 und eines Auslaufrollganges 21 die Anlage.After leaving the
Der Transport der Chargen 4 durch die erfindungsgemäße Anlage wird, wie
insbesondere aus Fig. 1 ersichtlich ist, durch eine Rollenbahn 22 durchgeführt, die
eine langsame, horizontale Pendelbewegung der Charge während Aufheizung,
Aufkohlung und Abschreckung zur Vergleichmäßigung des Behandlungsergebnisses
ermöglicht.The transport of the
Eine bevorzugte Ausbildung der Abschreckkammer 17 ist im Schnitt in Fig.
3 dargestellt. Gemäß dieser Figur ist auf ein Gehäuse 31 ein Motor 32 aufgesetzt,
der ein Ventilatorrad 33 antreibt. Innerhalb des unteren Teiles 34 eines im Gehäuse
31 verlaufenden rund oder eckig ausgeführten Mantels liegt die Charge 4 auf den
Transportrollen 22. Der Mantel erweitert sich nach oben hin und innerhalb des
erweiterten Teiles 37 ist ein Wärmetauscher 38 angeordnet. Dieser Wärmetauscher
38 nimmt jedoch nicht den gesamten Raum innerhalb des Teiles 37 des Mantels
ein, sodaß ein freier Querschnitt 39 gebildet ist.A preferred embodiment of the
Das Ventilatorrad 33 fördert Stickstoffgas im Sinne der eingetragenen Pfeile
außerhalb des Mantels 34, 37 nach unten, wo es um 90° umgelenkt wird und nach
oben unter Kühlung der Charge 4 an dieser vorbei streicht. Anschließend
durchströmt das Kühlgas zum Teil den Wärmetauscher 38, zum Teil den freien
Querschnitt 39, wobei sich die beiden Ströme vor dem Eintritt in das Ventilatorrad
33 wieder vereinigen.The
Die Transportrollen 22 der Abschreckkammer 17 ermöglichen ein
Reversieren der Charge durch horizontale Pendelbewegung, wodurch die
Gleichmäßigkeit der Abschreckung verbessert werden kann. Die im Chargenraum
befindliche, bewegliche Gasleiteinrichtung 35 begrenzt die vom Kühlgas
bestrichene Fläche weitgehend auf die Chargengrundfläche und führt den freien
Querschnitt mit der Charge mit. Dadurch wird verhindert, daß das Kühlgas
abwechselnd vor und hinter der Charge vorbeiströmt, wenn diese während der
Abkühlung pendelnd reversiert wird. Die Bewegung der Gasleiteinrichtung kann
vorzugsweise über den Rollenantrieb erfolgen. Andere Lösungen, wie z.B. die
Verschiebung mittels Pneumatikzylindern sind ebenfalls möglich.The
Nach Aufbringen eines Systemdrucks von max. 4 MPa wird Stickstoff
innerhalb der Vorrichtung durch das Ventilatorrad 33 umgewälzt, wobei sich ein
auf die Ebenen E1 und E3 bezogener Leitwert von 20 - 500 [m3/kPas] einstellt
und die Druckdifferenz in der Ebene E2 zwischen dem Bypass und knapp hinter
dem Wärmetauscher möglichst gering gehalten wird.After applying a system pressure of max. 4 MPa, nitrogen is circulated within the device by the
Um die beiden Teilströme an unterschiedliche Chargengrößen und
Gasdrücke anzupassen, kann im Bypass-System bzw. freien Querschnitt 39
zusätzlich eine Regelklappe 41 installiert werden, die über die Druckdifferenz
zwischen Bypass und unmittelbar hinter dem Wärmetauscher in der Ebene 2
solcher Art angesteuert wird, daß die Abkühlzeit der Charge minimiert wird. Zur
Bestimmung der optimalen Klappenposition kann der Meßwert mit einer
Auswerteeinheit (Rechner) verbunden werden.To the two partial streams to different batch sizes and
Adjusting gas pressures can be done in the bypass system or
Eine bevorzugte Ausführung der Transportrollen ist in Fig. 5 dargestellt.
Die Transportrollen 22 werden hier erfindungsgemäß durch Keramik- oder
Grafitlager 42 gehalten, die sich innerhalb der heißen Aufheiz-, Aufkohlungs- und
Diffusionskammer 43 befinden und die auf der darunterliegenden Isolation 44
aufliegen. Mehrere Transportrollen werden dabei mittels Kettenantrieb außerhalb
der Heizkammer verbunden.A preferred embodiment of the transport rollers is shown in FIG. 5.
The
Wie in Fig. 6 dargestellt, erfolgt der Antrieb der solcherart verbundenen
Transportrollen durch eine dünne Antriebswelle 45 und 46, die kein Biegemoment
übertragen muß. Durch diese Maßnahmen werden die Energieverluste minimiert.As shown in Fig. 6, the drive of such connected
Transport rollers through a
Eine andere Ausführungsvariante ist in Fig. 7 dargestellt. Danach können die
Transportrollen in der Aufheiz-, Aufkohlungs- und Diffusionszone als hohle
Zylinder 47 ausgeführt sein, in die ein Elektroheizelement oder Gasbrenner
eingebracht wird und die mittels einer Drehdurchführung 48 angeflanscht werden.
Dadurch wird die gesamte Anzahl an Durchführungen in die Aufheiz-,
Aufkohlungs- und Diffusionskammern verringert.Another embodiment variant is shown in FIG. 7. Then you can
Transport rollers in the heating, carburizing and diffusion zone as a
Im Rahmen der Erfindung sind zahlreiche Abänderungen möglich. So könnte
z.B. die Abschreckkammer 17 mit absenkbaren Transportrollen ausgeführt sein, die
die Charge auf einem feststehenden Chargenträger absetzen, die Zahl der
Aufkohlungskammern könnte von zwei und die Zahl der Diffusionskammern von
drei abweichen.Numerous modifications are possible within the scope of the invention. So could
e.g. the quenching
Claims (10)
- A low-pressure carbonisation plant with several chambers arrayed one after another, through which charges are moved by means of transportation organs, defined by the combination of the following already known characteristics:the transportation organs take the form of a roller conveyance (22), which conveys the charges (4) one after another througha vacuum-tight entry sluice (6),an evacuatable heating chamber (7), in which the charges (4) can be heated under nitrogen at a pressure of from 100 to 200 kPa (1 to 2 bar),at least one carbonisation chamber (10, 11) for carbonising with carbonising gas at a pressure of from 0.1 to 60 kPa abs. (1 to 600 mbar abs.), preferably from 1 to 3 kPa abs. (10 to 30 mbar abs.),at least one diffusion chamber (13, 14) anda quenching chamber (17) for high-pressure gas quenching.
- A plant according to claim 1, in which the heating of the low-pressure carbonisation chamber and/or of the diffusion chamber takes place by means of jacket jet pipes, preferably by means of electric jet pipes or gas jet pipes.
- A plant according to claim 1, in which the rollers of the roller conveyor (22) can be moved in an oscillating motion.
- A plant according to claim 1, in which a movable gas duct installation (35) situated inside the charge space limits the area affected by the cooling gas to the charge area and conveys the free cross-section with the charge.
- A plant according to claim 4, in which the movement of the gas duct installation (35) takes place by means of the roller drive.
- A plant according to claim 4, in which the movement of the gas duct installation (35) takes place by means of pneumatic cylinders.
- A plant according to one of the claims 1 to 6, in which the quenching chamber (17) is followed by a small roller hearth starter furnace (19).
- A plant according to one of the claims 1 to 7, in which two separate carbonisation chambers (10, 11) are arrayed one after the other.
- A plant according to one of the claims 1 to 8, in which the rollers take the form of hollow cylinders (47), in which electric jet elements are inserted and held in place by means of a rotary transmission leadthrough (48).
- A plant according to one of the claims 1 to 8, in which the rollers (22) in the charge space are supported by ceramic or graphite bearings (42), which are capable of taking up the bending moment and rest on the insulation (44) situated in an underlying position.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT1635/96 | 1996-09-16 | ||
| AT0163596A AT404029B (en) | 1996-09-16 | 1996-09-16 | LOW-PRESSURE REARING PLANT |
| AT163596 | 1996-09-16 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0829554A1 EP0829554A1 (en) | 1998-03-18 |
| EP0829554B1 true EP0829554B1 (en) | 2000-04-26 |
| EP0829554B2 EP0829554B2 (en) | 2004-05-12 |
Family
ID=3517678
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP97890166A Expired - Lifetime EP0829554B2 (en) | 1996-09-16 | 1997-08-19 | Low pressure carburising device with a plurality of sequentially arranged chambers |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0829554B2 (en) |
| AT (1) | AT404029B (en) |
| DE (1) | DE59701501D1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4540406B2 (en) * | 2004-06-25 | 2010-09-08 | 富士重工業株式会社 | Multi-stage continuous carburizing and quenching furnace and continuous carburizing and quenching method |
| DE102008020449A1 (en) * | 2008-04-01 | 2009-10-15 | Manfred Husslein | Industrial furnace and method for operating an industrial furnace |
| CN108315544A (en) * | 2018-04-08 | 2018-07-24 | 亚捷科技（唐山）股份有限公司 | A kind of amino atmosphere roller stick furnace production system |
| CN110835722B (en) * | 2019-11-27 | 2023-08-25 | 特诺恩技术（天津）有限公司 | Sliding sealing furnace door for gear carburizing heat treatment |
| CN110846612A (en) * | 2019-12-03 | 2020-02-28 | 上海丰东热处理工程有限公司 | Vacuum carburizing heat treatment processing technology |
| CN114293136B (en) * | 2021-12-31 | 2024-08-02 | 重庆市星极齿轮有限责任公司 | Workpiece heat treatment system |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1208134A (en) * | 1967-03-22 | 1970-10-07 | Gibbons Brothers Ltd | Improvements in or relating to continuous carburising |
| US3662996A (en) * | 1970-03-23 | 1972-05-16 | Holcroft & Co | Multi-chamber carburizing apparatus |
| JPS58130270A (en) * | 1982-01-27 | 1983-08-03 | Michio Sugiyama | Continuous vacuum carburizing furnace and its operation method |
| JPS60138065A (en) * | 1983-12-27 | 1985-07-22 | Chugai Ro Kogyo Kaisha Ltd | Gas carburizing and quenching method and continuous gas carburizing and quenching equipment |
| JPS60190511A (en) * | 1984-03-13 | 1985-09-28 | Ishikawajima Harima Heavy Ind Co Ltd | Metal heat treatment equipment |
| FR2678287B1 (en) * | 1991-06-26 | 1993-10-29 | Etudes Constructions Mecaniques | LOW PRESSURE CEMENTATION PROCESS AND FURNACE. |
| JPH055852U (en) † | 1991-07-02 | 1993-01-26 | 中外炉工業株式会社 | Multi-chamber roller hearth type ion carburizing furnace |
| FR2681332B1 (en) * | 1991-09-13 | 1994-06-10 | Innovatique Sa | METHOD AND DEVICE FOR CEMENTING STEEL IN A LOW PRESSURE ATMOSPHERE. |
| KR100266037B1 (en) * | 1992-10-15 | 2000-09-15 | 에모토 간지 | Continuous carburizing method of metal stand |
| JP3448789B2 (en) * | 1995-01-20 | 2003-09-22 | 同和鉱業株式会社 | Gas carburizing method |
| DE29505496U1 (en) * | 1995-03-31 | 1995-06-01 | Ipsen Industries International GmbH, 47533 Kleve | Device for the heat treatment of metallic workpieces under vacuum |
-
1996
- 1996-09-16 AT AT0163596A patent/AT404029B/en not_active IP Right Cessation
-
1997
- 1997-08-19 DE DE59701501T patent/DE59701501D1/en not_active Expired - Fee Related
- 1997-08-19 EP EP97890166A patent/EP0829554B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| ATA163596A (en) | 1997-12-15 |
| EP0829554B2 (en) | 2004-05-12 |
| DE59701501D1 (en) | 2000-05-31 |
| EP0829554A1 (en) | 1998-03-18 |
| AT404029B (en) | 1998-07-27 |
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