EP0080124A2 - Procédé de cémentation de pièces métalliques - Google Patents

Procédé de cémentation de pièces métalliques Download PDF

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Publication number
EP0080124A2
EP0080124A2 EP82110429A EP82110429A EP0080124A2 EP 0080124 A2 EP0080124 A2 EP 0080124A2 EP 82110429 A EP82110429 A EP 82110429A EP 82110429 A EP82110429 A EP 82110429A EP 0080124 A2 EP0080124 A2 EP 0080124A2
Authority
EP
European Patent Office
Prior art keywords
carbon
containing gas
addition
workpieces
duration
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
EP82110429A
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German (de)
English (en)
Other versions
EP0080124A3 (en
EP0080124B1 (fr
Inventor
Thomas Dipl.-Ing. Mahlo
Karl Dipl.-Chem Dörhöfer
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.)
Linde GmbH
Original Assignee
Linde GmbH
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Filing date
Publication date
Application filed by Linde GmbH filed Critical Linde GmbH
Publication of EP0080124A2 publication Critical patent/EP0080124A2/fr
Publication of EP0080124A3 publication Critical patent/EP0080124A3/de
Application granted granted Critical
Publication of EP0080124B1 publication Critical patent/EP0080124B1/fr
Expired legal-status Critical Current

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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
    • 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 method for case hardening metallic workpieces, wherein the workpieces are exposed to the action of a carbon-containing gas mixture, to which one or more carbon-containing gas components are added in a pulsating manner during their action on the workpieces.
  • Pulsating addition of the carbon-containing gas component achieves a large carbon potential gradient in a method of the type mentioned above.
  • Pulsating addition of a carbon-containing gas component means adding it to the gas mixture during numerous cycles consisting of two different phases. In the first phase of a cycle, the carbon-containing gas is added to the gas mixture in a pulsed manner and the carbon potential of the gas atmosphere is raised to a certain level. In the second phase, the supply of carbon-containing gas is interrupted, i.e. no carbon-containing gas is supplied to the gas mixture. This reduces the carbon potential of the gas atmosphere.
  • the invention is therefore based on the object of specifying a method of the type mentioned at the outset with which workpieces can be carburized or carbonitrided uniformly, carbides formed being largely removed.
  • This object is achieved in that the addition of the carbon-containing gas component (s) is interrupted after several cycles each consisting of a phase of the pulse-like addition of carbon-containing gas and a subsequent phase without the addition of carbon-containing gas and only after the end of one compared to Duration of a cycle long pause is resumed.
  • the carburizing or carbonitriding process is no longer divided into two-phase cycles. Rather, the case hardening method according to the invention is composed of several intervals, each consisting of several cycles followed by a pause. As in the known method, cycle is to be understood as the brief addition of a hydrocarbon to the gas mixture with subsequent interruption of the hydrocarbon supply.
  • the carbon concentration in the edge area of the workpieces drops in every interval. At the beginning of the next interval, therefore, is the gradient of the Koh and the carbon transfer in the workpiece is very high.
  • the amount of carbon-containing gas supplied in a cycle or the number of cycles is selected such that the supply of the carbon-containing gas is cut off as soon as carbon saturation is reached in the edge layer of the workpieces.
  • the total carburizing time is made up of the periods in which carbon is introduced into the workpiece and the periods in which the carbon diffuses in the workpiece. According to the invention, the duration of the carbon introduction is considerably shorter than that of the diffusion.
  • the process according to the invention causes the very stable carbides to dissolve during an interval, so that an excellent, surface oxidation-free surface quality of the workpieces is achieved. Because of this feature, the proposed method can also be used in push-through furnaces.
  • the amount of nitrogen supplied per unit of time is increased for the duration of the pulsating addition of the carbon-containing gas component (s).
  • the furnace in which the workpieces are treated is constantly gassed with nitrogen to ensure an inert basic gas atmosphere in the furnace chamber.
  • the amount of nitrogen is increased for the duration of the pulsating hydrocarbon addition in order not to let the concentration of the hydrocarbon radicals become too high. Otherwise they would react with each other and form soot and would no longer contribute to carburization.
  • the pause lasts by a factor of 10 to 100 times longer than the previous cycles.
  • carbide compounds are still largely eliminated, but the duration of the case hardening process is minimal.
  • a particularly simple regulation is possible in the method according to the invention if, according to an advantageous variant, the duration of the cycles is kept constant during case hardening.
  • the carbon-containing gas is consequently pulsed into the furnace chamber at constant time intervals.
  • the gas atmosphere is formed exclusively from an inert gas, in particular nitrogen, and a carbon-containing gas, in particular propane.
  • An annealing furnace 1 is connected via a line 2 to a soot sensor 3 and a control unit 4.
  • the gas components nitrogen and a hydrocarbon in the exemplary embodiment propane, are now introduced into the annealing furnace 1.
  • Supply lines 5 (nitrogen) and 6 (propane) are used for this.
  • Valves 7, 8, 9, 10 and 11 control the addition of nitrogen and propane from the suitable tanks in which these components are stored in liquid form. Nitrogen and propane are mixed before entering the annealing furnace 1 and passed into the furnace via a line 12.
  • valve 9 in a line 13 is open, while valves 7 and 10 are closed. At this point, the furnace atmosphere consists essentially of nitrogen.
  • the carburizing or carbonitriding process begins as soon as a suitable temperature of approx. 800 to 1000 ° C has been reached in the furnace.
  • solenoid valve 10 is opened according to the invention.
  • Valve 10 is opened and closed by control unit 4 at constant time intervals.
  • a certain amount of nitrogen is always passed into the furnace per unit time during case hardening.
  • the amount of nitrogen supplied is increased in order not to make the concentration of the hydrocarbon radicals too great. Otherwise the radicals would react with one another and form soot.
  • solenoid valve 7 is in a bypass Line 14 opened by the control unit 4.
  • the propane is unstable at the high temperatures prevailing in the interior of the annealing furnace and disintegrates spontaneously.
  • the fission products are very reactive and enable the workpiece surface layer to be saturated quickly with carbon. Because of the resulting significant carbon potential difference between the workpiece surface and the core, the carbon quickly diffuses into the edge layer of the workpieces.
  • Soot can now be formed in the gas mixture.
  • the amount of propane is reduced before a minimum soot value is reached.
  • the value determined by the sensor 3 is sent to the control unit 4, in which the measured value is compared with a predetermined setpoint signal. A difference between the measured value signal and the desired value signal is converted into a signal by which a control valve 11 in the supply line 6 for propane is controlled.
  • valve 10 - triggered by control unit 4 - is closed for a pause which lasts longer than the previous cycles and only nitrogen is fed into the furnace via line 13 with valve 9.
  • the carbon concentration in the edge region of the workpiece drops again, so that at the beginning of the interval consisting of several cycles with a subsequent pause, the gradient and thus the carbon transition into the workpiece is high.
  • the carbon not only diffuses into the workpiece, but also the unwanted carbides on the workpiece surface are redissolved and removed.
  • valves 7 and 10 are closed and the workpieces are lowered to the hardening temperature.
  • the carbon content in the gas mixture (e.g. in% by volume) is shown schematically against time (in seconds).
  • an interval of the method according to the invention is shown which lasts from the time zero to the time T '.
  • the carbon content of the gas mixture is briefly increased in several cycles, each of which takes time t.
  • a cycle consists of phase I (duration t 1 ) and phase II (duration t 2 ).
  • phase I propane is added to the gas mixture in pulses, while in phase II no propane is added to the gas mixture.
  • phase II the carbon content therefore decreases.
  • the carbon content does not drop to 0. It is only in the pause (duration T) that follows after several cycles (only the first four cycles in the first interval are shown in the sketch), in which no propane is fed into the furnace the carbon content to 0.
  • a typical interval contains up to 15 cycles.
  • the addition periods depend on the furnace volume and the tightness of the furnace.
  • phase I lasts 5 to 15 seconds
  • phase II on the other hand, 15 to 60 seconds.
  • T 30 minutes
  • the method according to the invention enables rapid case hardening of workpieces with low consumption of carbon carriers. Since carbides formed are redissolved by the procedure according to the invention, piercing furnaces can also be used. be used in this process.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Regulation And Control Of Combustion (AREA)
  • Arc Welding Control (AREA)
  • Contacts (AREA)
EP82110429A 1981-11-20 1982-11-11 Procédé de cémentation de pièces métalliques Expired EP0080124B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3146042 1981-11-20
DE19813146042 DE3146042A1 (de) 1981-11-20 1981-11-20 Verfahren zum einsatzhaerten metallischer werkstuecke

Publications (3)

Publication Number Publication Date
EP0080124A2 true EP0080124A2 (fr) 1983-06-01
EP0080124A3 EP0080124A3 (en) 1984-08-22
EP0080124B1 EP0080124B1 (fr) 1986-09-24

Family

ID=6146826

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82110429A Expired EP0080124B1 (fr) 1981-11-20 1982-11-11 Procédé de cémentation de pièces métalliques

Country Status (9)

Country Link
EP (1) EP0080124B1 (fr)
AT (1) AT373294B (fr)
AU (1) AU548340B2 (fr)
BR (1) BR8206714A (fr)
DE (2) DE3146042A1 (fr)
ES (1) ES8307921A1 (fr)
GR (1) GR77758B (fr)
NO (1) NO823887L (fr)
ZA (1) ZA828553B (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0408511A1 (fr) * 1989-07-13 1991-01-16 Solo Fours Industriels Sa Procédé et installation de traitement thermique ou thermochimique d'un acier
FR2656003A1 (fr) * 1989-12-14 1991-06-21 Gantois Michel Procede et installation de traitement thermique ou thermochimique d'un acier, permettant le controle de l'enrichissement en carbone de la zone superficielle.
FR2681332A1 (fr) * 1991-09-13 1993-03-19 Innovatique Sa Procede et dispositif de cementation d'un acier dans une atmosphere a basse pression.
WO2001055470A2 (fr) * 2000-01-28 2001-08-02 Swagelok Company Procedes modifies de cementation a basse temperature
EP1160349A1 (fr) * 2000-05-24 2001-12-05 Ipsen International GmbH Procédé et appareil de traitement thermique de pièces métalliques
FR2821362A1 (fr) * 2001-02-23 2002-08-30 Etudes Const Mecaniques Procede de cementation basse pression
WO2003097893A1 (fr) * 2002-05-15 2003-11-27 Linde Aktiengesellschaft Procede et dispositif de traitement thermique de pieces metalliques
EP2034038A3 (fr) * 2007-08-17 2009-09-02 Robert Bosch GmbH Procédé de fabrication d'une couche de protection contre l'usure sur un composant magnétique mou
WO2012048669A1 (fr) 2010-10-11 2012-04-19 Ipsen International Gmbh Procédé et dispositif de carburation et carbonitruration de matériaux métalliques
US8828150B2 (en) 2007-10-01 2014-09-09 Robert Bosch Gmbh Method for carburizing workpieces and its application
EP2541177A3 (fr) * 2005-11-23 2014-09-24 Surface Combustion, Inc. Système de distribution de fluide d'un four atmosphérique pour le traitement de surface d' articles métalliques

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103556106B (zh) * 2013-10-30 2015-10-28 西安航空动力股份有限公司 一种1Cr17Ni2合金材料高温真空渗碳层的制备方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE618026C (de) * 1932-08-28 1935-08-30 Ewald Hanus Verfahren zum Zementieren von Eisen und Stahl
DE726134C (de) * 1938-03-30 1942-10-07 Louis Renault Verfahren und Vorrichtung zum Haerten von Stahl im Gasmuffelofen
FR1164640A (fr) * 1955-12-06 1958-10-13 Elino Ind Ofenbau Carl Hanf & Procédé pour la cémentation, la nitruration et la carbonitruration de pièces en acier
DE2851982A1 (de) * 1978-12-01 1980-06-12 Degussa Verfahren zum steuern von aufkohlungsprozessen im unterdruckbereich
EP0049531A1 (fr) * 1980-10-08 1982-04-14 Linde Aktiengesellschaft Procédé pour la cémentation gazeuse de pièces en acier
EP0049530A1 (fr) * 1980-10-08 1982-04-14 Linde Aktiengesellschaft Procédé et dispositif pour carburer des pièces en acier

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE618026C (de) * 1932-08-28 1935-08-30 Ewald Hanus Verfahren zum Zementieren von Eisen und Stahl
DE726134C (de) * 1938-03-30 1942-10-07 Louis Renault Verfahren und Vorrichtung zum Haerten von Stahl im Gasmuffelofen
FR1164640A (fr) * 1955-12-06 1958-10-13 Elino Ind Ofenbau Carl Hanf & Procédé pour la cémentation, la nitruration et la carbonitruration de pièces en acier
DE2851982A1 (de) * 1978-12-01 1980-06-12 Degussa Verfahren zum steuern von aufkohlungsprozessen im unterdruckbereich
EP0049531A1 (fr) * 1980-10-08 1982-04-14 Linde Aktiengesellschaft Procédé pour la cémentation gazeuse de pièces en acier
EP0049530A1 (fr) * 1980-10-08 1982-04-14 Linde Aktiengesellschaft Procédé et dispositif pour carburer des pièces en acier

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Lueger, Lexikon der Hüttentechnik, p. 150-152 *

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0408511A1 (fr) * 1989-07-13 1991-01-16 Solo Fours Industriels Sa Procédé et installation de traitement thermique ou thermochimique d'un acier
FR2656003A1 (fr) * 1989-12-14 1991-06-21 Gantois Michel Procede et installation de traitement thermique ou thermochimique d'un acier, permettant le controle de l'enrichissement en carbone de la zone superficielle.
FR2681332A1 (fr) * 1991-09-13 1993-03-19 Innovatique Sa Procede et dispositif de cementation d'un acier dans une atmosphere a basse pression.
US6547888B1 (en) 2000-01-28 2003-04-15 Swagelok Company Modified low temperature case hardening processes
WO2001055470A2 (fr) * 2000-01-28 2001-08-02 Swagelok Company Procedes modifies de cementation a basse temperature
WO2001055470A3 (fr) * 2000-01-28 2001-12-27 Swagelok Co Procedes modifies de cementation a basse temperature
EP1160349A1 (fr) * 2000-05-24 2001-12-05 Ipsen International GmbH Procédé et appareil de traitement thermique de pièces métalliques
WO2002068707A1 (fr) * 2001-02-23 2002-09-06 Etudes Et Constructions Mecaniques Procede de cementation basse pression
FR2821362A1 (fr) * 2001-02-23 2002-08-30 Etudes Const Mecaniques Procede de cementation basse pression
US7118634B2 (en) 2001-02-23 2006-10-10 Bnp Parlbas Low-pressure cementation method
WO2003097893A1 (fr) * 2002-05-15 2003-11-27 Linde Aktiengesellschaft Procede et dispositif de traitement thermique de pieces metalliques
EP2541177A3 (fr) * 2005-11-23 2014-09-24 Surface Combustion, Inc. Système de distribution de fluide d'un four atmosphérique pour le traitement de surface d' articles métalliques
EP2541176A3 (fr) * 2005-11-23 2014-09-24 Surface Combustion, Inc. Système de distribution de fluide d'un four atmosphérique pour le traitement de surface d' articles métalliques
EP2034038A3 (fr) * 2007-08-17 2009-09-02 Robert Bosch GmbH Procédé de fabrication d'une couche de protection contre l'usure sur un composant magnétique mou
US8828150B2 (en) 2007-10-01 2014-09-09 Robert Bosch Gmbh Method for carburizing workpieces and its application
WO2012048669A1 (fr) 2010-10-11 2012-04-19 Ipsen International Gmbh Procédé et dispositif de carburation et carbonitruration de matériaux métalliques

Also Published As

Publication number Publication date
EP0080124A3 (en) 1984-08-22
DE3146042A1 (de) 1983-05-26
GR77758B (fr) 1984-09-25
DE3273483D1 (en) 1986-10-30
AT373294B (de) 1984-01-10
ZA828553B (en) 1983-09-28
ATA84282A (de) 1983-05-15
AU9040182A (en) 1983-05-26
EP0080124B1 (fr) 1986-09-24
AU548340B2 (en) 1985-12-05
ES517532A0 (es) 1983-08-01
BR8206714A (pt) 1983-10-04
NO823887L (no) 1983-05-24
ES8307921A1 (es) 1983-08-01

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