EP0535319A1 - Four sous vide pour la carburisation de pièces métalliques par plasma - Google Patents

Four sous vide pour la carburisation de pièces métalliques par plasma Download PDF

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Publication number
EP0535319A1
EP0535319A1 EP92112630A EP92112630A EP0535319A1 EP 0535319 A1 EP0535319 A1 EP 0535319A1 EP 92112630 A EP92112630 A EP 92112630A EP 92112630 A EP92112630 A EP 92112630A EP 0535319 A1 EP0535319 A1 EP 0535319A1
Authority
EP
European Patent Office
Prior art keywords
vacuum furnace
heating chamber
batch
vacuum
gas
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.)
Granted
Application number
EP92112630A
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German (de)
English (en)
Other versions
EP0535319B1 (fr
Inventor
Bernd Dr. Edenhofer
Albert Fleiter
Jürgen Schröder
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ipsen International GmbH
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Ipsen International GmbH
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Publication date
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=6441930&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0535319(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Ipsen International GmbH filed Critical Ipsen International GmbH
Publication of EP0535319A1 publication Critical patent/EP0535319A1/fr
Application granted granted Critical
Publication of EP0535319B1 publication Critical patent/EP0535319B1/fr
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    • 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
    • C23C8/36—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 using ionised gases, e.g. ionitriding
    • C23C8/38—Treatment of ferrous surfaces

Definitions

  • the invention relates to a vacuum furnace for the plasma carburization of metallic workpieces in an artificially generated electric field by means of a carbon-containing gas with an electric heating device, a vacuum pump for generating a vacuum in the heating chamber and gas inlet openings by means of which cooling gas of the batch conveyed by a blower and guided via a heat exchanger is fed.
  • Vacuum furnaces for the plasma carburization of metallic workpieces using a carbon-containing gas, for example methane or propane, are known.
  • the batch is heated in the vacuum furnace to a temperature between approximately 800 and 1050 ° C.
  • the carbon-containing process gas is then passed into the furnace chamber and an electric field is applied to the batch.
  • the batch is electrically connected to an external power supply and forms the cathode, while the furnace housing takes over the function of the anode.
  • the batch is therefore placed at a high negative potential with respect to the furnace chamber, this furnace chamber usually being at earth potential.
  • the invention has for its object to provide a vacuum furnace for plasma carburizing metallic workpieces, which is much smaller than known carburizing furnaces of this type in a similar application.
  • the furnace housing designed as a pressure vessel is designed for a pressure of at least 10 bar with regard to its permissible pressure load and the drive of the blower with regard to the gas pressure achievable during cooling of the batch, and the gas inlet openings carrying the cooling gas are arranged in the heating chamber and are aligned with the batch.
  • the batch is cooled during hardening by the batch flowing through the cooling gas emerging from the gas inlet openings.
  • the heat removed from the charge by the movement of the cooling gas is not sufficient.
  • the furnace housing as a pressure vessel and also to design the drive of the fan so that the vacuum furnace can be operated at a pressure of at least 10 bar.
  • the resulting density of the cooling gas which corresponds to a multiple of the density at conventional pressures, leads to a significantly improved heat transfer and thus to a higher cooling capacity during hardening.
  • nozzles are provided as gas inlet openings on all sides around the heating chamber, the outlet openings of which are aligned with the batch. This results in a uniform cooling of the batch and thus an even hardening result.
  • the heating chamber is surrounded on all sides by heating elements of the electrical heating device.
  • the heating elements are advantageously arranged in a ring around the heating chamber.
  • a distribution chamber which surrounds the heating chamber in an annular manner for supplying the cooling gas to the gas inlet openings is proposed.
  • the cooling gas flow is distributed particularly uniformly over the preferably nozzle-shaped gas inlet openings.
  • the distribution chamber be enclosed by a jacket arranged in the furnace housing, an annular space for returning the cooling gas being located between the jacket and the furnace housing.
  • a jacket arranged in the furnace housing, an annular space for returning the cooling gas being located between the jacket and the furnace housing.
  • batch supports penetrating the casing are fastened to the inner wall of the furnace housing, the batch supports being electrically insulated from the casing.
  • the jacket also acts as an anode, so that only the batch and parts of the batch supports form the cathode of the electric field generated.
  • the cathode-side electrical connection be made through at least one of the batch supports. This simplifies the construction of the vacuum furnace, since no separate bushings through the jacket and the wall of the heating chamber are required for the cathode cable.
  • the furnace housing be connected via a line to a buffer container which contains helium as the cooling gas at a pressure of at least 10 bar.
  • a buffer container which contains helium as the cooling gas at a pressure of at least 10 bar.
  • the vacuum furnace for carburizing plasma in FIG. 1 consists of a furnace housing 1, which can be closed on one side by a furnace door 2 in a pressure-tight manner. On the opposite end of the furnace housing 1, a powerful electric drive 4 is arranged within a pressure-resistant cap 3. Furnace housing 1, furnace door 2 and cap 3 as well as all flanges and other connecting parts are designed to be pressure-resistant in the vacuum furnace according to the exemplary embodiment and designed for an operating pressure of at least 20 bar.
  • Fig. 1 shows in connection with Fig. 2 that in the heating chamber wall 5 a plurality of gas inlet openings in the form of nozzles 9 is embedded.
  • the nozzles allow the passage of cooling gas from a distribution chamber 10 enclosing the heating chamber wall 5 into the heating chamber 6.
  • the nozzles 9 are distributed over the entire circumference of the heating chamber 6 and are each aligned such that the cooling air jet emerging from the nozzles 9 directly onto the charge 7 reached.
  • the heating chamber can also be designed differently, with the cooling gas crossing the batch in vertical or horizontal directions via open hatches in the heating chamber.
  • Each heating element 11 consists of a strip of graphite which is bent several times and thus takes the form of an almost closed polygon.
  • the heating elements 11 are connected to a common power supply 12.
  • a total of four heating elements 11 are provided which, due to their ring-like shape which surrounds the charge 7 on all sides, enable uniform radiation heating of the charge 7.
  • the vacuum furnace is provided for the carburizing of metal workpieces and is connected to a generator 15 via current conductors 13, 14.
  • the current conductor 13 forms the positive connection and is connected directly to the furnace housing 1 and thus to the earth potential.
  • the current conductor 14 is passed through one of the batch supports 8 in an insulated manner and makes direct electrical contact with a metallic batch carrier 16 on which the batch 7 rests.
  • Insulations 17 on the batch supports 8 prevent metallic contact and thus short circuits between the negatively charged batch supports 8 and the positively charged furnace housing 1 as well as a likewise positively charged metallic jacket 18 surrounding the distribution chamber 10.
  • the batch 7 is first placed on the batch supports 8 or the batch carrier 16.
  • the heating elements 11 are operated via the power supply 12. This takes place as a function of signals from a central controller 19.
  • a carbon-containing gas for example methane or propane, is introduced into the vacuum furnace via a connection 20.
  • the generator 15 is switched on via the controller 19, so that the electric field forms in the heating chamber 6 and the plasma carburization begins.
  • the power supply 12 and the generator 15 are switched off and the carbon-containing atmosphere is broken down.
  • a cooling gas is then introduced into the furnace housing 1 and the electric drive 4 is put into operation.
  • Helium is used as the cooling gas in the embodiment shown in the drawing.
  • Helium shows very good heat transfer coefficients, which at a cooling gas pressure of 20 bar are approximately three times the values of nitrogen at a cooling gas pressure of 6 bar.
  • the helium is located in a buffer container 21 designed for a pressure of at least 10 bar and reaches the interior of the furnace housing 1 via a line 23 that can be controlled by a valve 22 Pressures designed fan 25 out.
  • the cooling gas conveyed by the blower 25 is distributed within the distribution chamber 10 to the individual nozzles 9 and flows with cooling effect directly to the batch 7.
  • the cooling gas is returned to the heat exchanger 24 via an annular space 26 between the jacket 18 and the furnace housing 1.
  • the pressure of the cooling gas prevailing in the interior of the furnace is 10 to 20 bar, but can be adapted to further increase the cooling effect as a result of a corresponding design adjustment can also be raised to values well above 20 bar.
  • nozzles 9 are arranged in a common radial plane which is axially offset from the radial plane defined by a heating element 11.
  • the area available on the inside of the heating chamber wall 5 is optimally used.
EP92112630A 1991-10-01 1992-07-23 Four sous vide pour la carburisation de pièces métalliques par plasma Revoked EP0535319B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4132712A DE4132712C2 (de) 1991-10-01 1991-10-01 Vakuumofen zur Plasmaaufkohlung metallischer Werkstücke
DE4132712 1991-10-01

Publications (2)

Publication Number Publication Date
EP0535319A1 true EP0535319A1 (fr) 1993-04-07
EP0535319B1 EP0535319B1 (fr) 1995-06-14

Family

ID=6441930

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92112630A Revoked EP0535319B1 (fr) 1991-10-01 1992-07-23 Four sous vide pour la carburisation de pièces métalliques par plasma

Country Status (4)

Country Link
EP (1) EP0535319B1 (fr)
AT (1) ATE123820T1 (fr)
DE (2) DE4132712C2 (fr)
ES (1) ES2074773T3 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0778463A1 (fr) * 1995-12-08 1997-06-11 The Perkin-Elmer Corporation Calorimètre avec refroidissement rapide d'un récipient pour chauffer en celui-ci
EP0869189A1 (fr) * 1997-03-11 1998-10-07 Linde Aktiengesellschaft Procédé de trempe en milieu gazeux de pièces métalliques
EP1318696A1 (fr) * 2001-11-28 2003-06-11 Ipsen International GmbH Procédé de chauffage électrique d'un four pour le traitment thermique de pièces métalliques
CN103557710A (zh) * 2013-10-28 2014-02-05 北京泰科诺科技有限公司 一种快速循环气冷真空炉
CN104296524A (zh) * 2013-07-16 2015-01-21 东阳市和顺磁业有限公司 一种高真空烧结炉
KR20180077729A (ko) 2016-12-29 2018-07-09 정원기 담금질 장치
CN108870983A (zh) * 2018-07-11 2018-11-23 昆山金美创机械有限公司 一种可选择进气方式的真空炉
KR20190112541A (ko) 2018-03-26 2019-10-07 정원기 담금질 장치

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10157840C1 (de) * 2001-11-24 2002-10-24 Ald Vacuum Techn Ag Vakuumofen zur Wärmebehandlung von metallischen Werkstücken
US10196730B2 (en) 2009-09-10 2019-02-05 Ald Vacuum Technologies Gmbh Method and device for hardening workpieces, and workpieces hardened according to the method
DE102009041041B4 (de) 2009-09-10 2011-07-14 ALD Vacuum Technologies GmbH, 63450 Verfahren und Vorrichtung zum Härten von Werkstücken, sowie nach dem Verfahren gehärtete Werkstücke
DE102020114053B4 (de) 2020-05-26 2022-07-14 Audi Aktiengesellschaft Prozessanordnung zur Herstellung eines warmumgeformten und pressgehärteten Stahlblechbauteils

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4124199A (en) * 1977-07-11 1978-11-07 Abar Corporation Process and apparatus for case hardening of ferrous metal work pieces

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3736501C1 (de) * 1987-10-28 1988-06-09 Degussa Verfahren zur Waermebehandlung metallischer Werkstuecke

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4124199A (en) * 1977-07-11 1978-11-07 Abar Corporation Process and apparatus for case hardening of ferrous metal work pieces

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 013, no. 367 (C-626)15. August 1989 & JP-A-01 123 059 ( DAIDO STEEL ) 16. Mai 1989 *
PATENT ABSTRACTS OF JAPAN vol. 013, no. 549 (C-662)7. Dezember 1989 & JP-A-01 225 764 ( DAIDO STEEL ) 8. September 1989 *
PATENT ABSTRACTS OF JAPAN vol. 014, no. 017 (C-675)16. Januar 1990 & JP-A-01 261 213 ( IDEMITSU PETROCHEM ) 18. Oktober 1989 *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0778463A1 (fr) * 1995-12-08 1997-06-11 The Perkin-Elmer Corporation Calorimètre avec refroidissement rapide d'un récipient pour chauffer en celui-ci
US5876118A (en) * 1995-12-08 1999-03-02 The Perkin-Elmer Corporation Calorimeter having rapid cooling of a heating vessel therein
EP0869189A1 (fr) * 1997-03-11 1998-10-07 Linde Aktiengesellschaft Procédé de trempe en milieu gazeux de pièces métalliques
EP1318696A1 (fr) * 2001-11-28 2003-06-11 Ipsen International GmbH Procédé de chauffage électrique d'un four pour le traitment thermique de pièces métalliques
US6794618B2 (en) 2001-11-28 2004-09-21 Ipsen International Gmbh Method for electrical heating of furnaces for heat treatment of metallic workpieces
CN104296524A (zh) * 2013-07-16 2015-01-21 东阳市和顺磁业有限公司 一种高真空烧结炉
CN103557710A (zh) * 2013-10-28 2014-02-05 北京泰科诺科技有限公司 一种快速循环气冷真空炉
CN103557710B (zh) * 2013-10-28 2016-06-15 北京泰科诺科技有限公司 一种快速循环气冷真空炉
KR20180077729A (ko) 2016-12-29 2018-07-09 정원기 담금질 장치
KR20190112541A (ko) 2018-03-26 2019-10-07 정원기 담금질 장치
CN108870983A (zh) * 2018-07-11 2018-11-23 昆山金美创机械有限公司 一种可选择进气方式的真空炉

Also Published As

Publication number Publication date
ATE123820T1 (de) 1995-06-15
DE4132712A1 (de) 1993-04-08
EP0535319B1 (fr) 1995-06-14
DE59202520D1 (de) 1995-07-20
DE4132712C2 (de) 1995-06-29
ES2074773T3 (es) 1995-09-16

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