US20080084011A1 - Low Pressure Thermochemical Treatment Machine - Google Patents
Low Pressure Thermochemical Treatment Machine Download PDFInfo
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- US20080084011A1 US20080084011A1 US11/658,261 US65826105A US2008084011A1 US 20080084011 A1 US20080084011 A1 US 20080084011A1 US 65826105 A US65826105 A US 65826105A US 2008084011 A1 US2008084011 A1 US 2008084011A1
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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
- C23C8/08—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
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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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0062—Heat-treating apparatus with a cooling or quenching zone
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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
- C23C8/08—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
Definitions
- the invention relates to a machine for thermochemical treatment of metal parts comprising at least one heating cell, one carbon enriching cell for enriching the surfaces of the parts to be treated, one carbon diffusion cell diffusing from the surface to the core of the parts, and at least one hardening cell, arranged in succession one after the other and having a length adapted to the duration of the treatment performed in each cell, the machine also comprising mechanical means for transferring and moving the parts from one cell to the next and insulating means to insulate the cells from one another during the different successive treatment phases.
- thermochemical treatment systems exist for carburizing and carbonitriding metal parts, in particular systems in the form of a case with a solid cement, systems in non-controlled atmosphere, systems in controlled atmosphere with a constant carbon potential, or low pressure systems with a pressure of about 5 mbar to 20 mbar, sometimes even up to 100 mbar.
- Carburizing and carbonitriding generally require a partial pressure of the carburizing gas, formed by a hydrocarbon, for example methane (CH 4 ), acetylene (C 2 H 2 ) or propane (C 3 H 8 ), and possibly a nitriding gas, for example ammoniac (NH 3 ).
- the carburizing operations i.e. carburizing temperature-setting treatment, surface enrichment treatment and carbon diffusion treatment, are preferably executed under partial nitrogen pressure. To prevent any oxidation during the carburizing treatment and during transport to the hardening cell, the parts are not exposed to air at any time.
- the hardening operation which follows the carburizing treatment, consists in cooling the parts rapidly. It is performed either in a bath of oils or molten salts or in a stirred gas at high pressure, such as nitrogen, helium or various mixtures of neutral gases such as carbon dioxide or hydrogen.
- the Patent EP-A-0922778 in particular, describes a thermal treatment installation comprising a plurality of cells designed for thermal treatment of a set of metal parts.
- the cells are all connected to a central enclosure at the same pressure as the treatment cells.
- the parts are transferred from one cell to another by means of transport and handling rails. After carburizing in the corresponding cell, the carburized parts are transferred to the hardening cell passing via the central enclosure, meaning that there is no contact with the ambient air.
- the phases of the carburizing treatment i.e. at least a carburizing temperature-setting phase, a carbon enrichment phase of the surface of the parts, and a diffusion phase of the carbon from the surface to the core of the parts, are successively performed in one and the same cell or in a single partitioned cell comprising mechanical means for advancing and transferring the parts.
- the mechanical means are then situated in a hot zone.
- the machine is a conventional gas-carburizing machine at atmospheric pressure and comprises one cell for each phase of the carburizing treatment, i.e. a carburizing heating cell, a carbon enriching cell for enriching the surfaces of the parts to be treated and a carbon diffusion cell for diffusing the carbon from the surface to the core of the parts.
- the cells are arranged in succession one after the other and the parts are moved from one cell to another to receive the carburizing treatment, the length of a cell being previously defined according to the required treatment time in the cells.
- this type of machine can only function under certain conditions, in particular under high pressures.
- the mechanical means for advancing and transferring the parts are situated in a hot zone, where the corresponding treatment is performed, and are not thermally insulated.
- this type of machine is difficult to integrate in existing production lines and the length of each cell can not easily be modulated according to the duration of the required treatment.
- the object of the invention is to remedy the above-mentioned drawbacks and to design a low pressure thermochemical carburizing or carbonitriding, treatment machine that is efficient, flexible and able to be easily adapted and integrated into mass production lines of parts.
- the temperature-setting, carbon enrichment and carbon diffusion cells are of standard shape and each comprise a low pressure treatment zone situated between an input module and an output module, the input and output modules each forming a cold zone thermally insulated from the treatment zone of the corresponding cell, the mechanical means for transferring and moving being situated in the input and output modules of the cells and the output module of a cell being connected to the input module of the adjacent cell.
- FIG. 1 schematically represents a top view of a first embodiment of a thermochemical treatment machine according to the invention.
- FIG. 2 schematically represents a top view of an alternative embodiment of a thermochemical treatment machine according to FIG. 1 .
- FIG. 3 represents a cell of the thermochemical treatment machine according to FIGS. 1 and 2 .
- FIGS. 4 to 6 schematically represent top views of alternative embodiments of a thermochemical treatment machine according to the invention.
- the thermochemical treatment machine is a machine 1 for low pressure carburizing treatment of metal parts under a vacuum.
- the machine 1 comprises a plurality of treatment cells 2 to 5 arranged in succession one after the other. Each cell corresponds to a particular phase of the low pressure carburizing treatment and presents a standard shape and a length L adaptable according to the duration of the treatment required in the cell.
- the manufacturing technique of the cells is that of cold-wall vacuum furnaces enabling an operating pressure comprised between 10 ⁇ 1 mbar and 30 mbar.
- the machine 1 also comprises means for moving and transferring the parts from one cell to the next and closing means designed to insulate one cell from the adjacent cells during the different phases of the carburizing treatment. Transfer of the parts between the cells is performed at a predetermined pressure, i.e. the carburizing pressure, of about 5 mbar to 20 mbar. Pumping systems keep the three cells at the same pressure, including during the transfer periods.
- a predetermined pressure i.e. the carburizing pressure
- the machine 1 comprises in particular a carburizing heating cell 2 .
- the object of the treatment performed in the cell 2 is to increase the temperature of the parts to the required carburizing temperature of about 880° C. to 1050° C.
- This phase is performed at the carburizing pressure of about 5 mbar to 20 mbar, preferably with nitrogen. In particular cases, the pressure can be increased up to 100 mbar.
- the machine 1 Downline from the carburizing heating cell 2 , the machine 1 comprises a carbon enriching cell 3 .
- the treatment performed in the cell 3 consists in enriching the surface of the parts in carbon or in carbon and nitrogen to increase the hardness of the parts after hardening.
- This enriching phase is preferably performed by injection of nitrogen or any other neutral gas at a temperature of about 880° C. to 1050° C. completed at regular intervals by injection of a cementing gas.
- the pressure in the cell 3 is for example about 5 mbar to 20 mbar depending on the cementing gas used.
- the parts are transferred to a final carbon diffusion cell 4 .
- the treatment performed in the cell 4 consists in diffusing the carbon into the thickness of the parts from the surface to the core of the parts, at the required depth of the cemented surface and the required percentage of carbon at the surface of the parts.
- This phase of the treatment is performed at the same pressure as that of the carburizing heating cell 2 and carbon enriching cell 3 .
- the temperature is adjusted, preferably between 880° C. and 1050° C., to enable a good penetration rate of the carbon into the parts and to obtain the optimum temperature of the parts before the hardening operation is performed.
- the required treatment temperature inside the carbon diffusion cell 4 is preferably different from the required treatment temperature inside the carburizing heating cell 2 and carbon enriching cell 3 .
- the machine 1 Downline from the cells 2 to 4 , the machine 1 also comprises a hardening cell 5 equipped with pressure-tight doors.
- the cell 5 is a hardening cell performing gas quenching, oil quenching, salt bath quenching or quenching in any other system enabling the parts to be cooled at the required speed to obtain the required hardness.
- the machine 1 can comprise a tempering cell downline from the hardening cell 5 .
- the tempering phase is performed at a temperature for example of about 200° C. to 300° C.
- the machine 1 Upline from the carburizing heating cell 2 , the machine 1 also comprises an input chamber 6 designed to store the parts waiting to enter the cell 2 ( FIG. 1 ). In this case, care must be taken to perform vacuum purging in the input chamber 6 so that the pressure in the chamber 6 is the same as that in the carburizing heating cell 2 , before the parts are input, and to ensure that the air is almost totally purged.
- the machine 1 comprises a gas pumping system 7 connected by suitable means to the carbon enriching cell 3 and designed to remove the gases present in the cells 2 , 3 and 4 .
- the pumping system 7 therefore advantageously generates a gas flow in the direction of the arrows F 1 , from the carburizing heating cell 2 and the carbon diffusion cell 4 to the carbon enriching cell 3 , which may be contaminated.
- the machine 1 can also comprise a first independent pumping system 8 of the input chamber 6 and a second independent pumping system 9 of the hardening cell 5 .
- the three cells 2 , 3 , 4 corresponding to the three indispensable phases of low pressure carburizing treatment, are cold-wall cells so as to be cold, non-polluting and not dangerous.
- the parts designed to be cemented have to pass successively, in order, via all the low pressure carburizing treatment cells 2 , 3 , 4 arranged one after the other.
- the cells 2 , 3 , 4 of the machine 1 are all shaped according to the same general model, of standard shape, adapted to each function (heating, enrichment and diffusion), and their length L is able to be modulated, which enables the treatment time of each cell to be adjusted precisely for a given treatment rate. Changing the rate notably enables different carburizing depths to be achieved.
- the length L of a cell is therefore proportional to the duration of the treatment performed in this cell.
- temperatures can be adapted to enable precise adjustment of the characteristics to be obtained on the parts to be treated.
- the cell 2 comprises an input module 10 a whereby the parts to be treated enter, and an output module 10 b whereby the parts exit after treatment.
- the input module 10 a and output module 10 b are of standard shape and can each contain a load 11 of metal parts.
- the cell 2 presents a longitudinal axis 12 oriented from the input module 10 a to the output module 10 b .
- the longitudinal axis 12 corresponds to the direction in which the loads 11 move, in the direction of the arrows F 2 , inside the cell 2 .
- the cell 2 comprises two identical standard intermediate modules 13 of the same length. Fitting several intermediate modules 13 between the input module 10 a and the output module 10 b enables the length L 1 of the cell 2 to be varied. For example, for the carbon diffusion cell 4 , the larger the number of modules 13 the greater the carburizing depth, at the same running rate of the loads 11 in the cell 4 .
- the standard modules 13 of the cell 2 constitute a low pressure treatment zone 14 within which the treatment proper to the cell 2 is performed.
- the treatment zone 14 preferably formed by standard modules 13 with cold walls, is confined and insulated from the input module 10 a and output module 10 b , which then constitute cold zones of the cell 2 .
- the cold zones are thermally insulated from the treatment zone 14 by means for example of thermally insulated cooled doors 15 arranged between the input module 10 a and output module 10 b and the confined treatment zone 14 .
- cooling of a door 15 is performed by means of a heat exchanger generating water circulation at the level of the door 15 .
- the input module 10 a and output module 10 b are of standard shape having a substantially U-shaped cross-section, and each comprise an opening in connection with the adjacent module 13 and three walls closing the end of the cell 2 .
- the input module 10 a comprises an input orifice 16 situated on a wall of the input module 10 a parallel to the longitudinal axis 12 of the cell 2
- the output module 10 b comprises an output orifice 17 situated on a wall of the output module 10 b parallel to the longitudinal axis 12 and situated on the same side of the cell 2 with respect to the longitudinal axis 12 .
- the loads 11 of the parts enter and exit via the same side of the cell 2 .
- the input module 10 a and output module 10 b each comprise for example an ejection system 18 designed to push and remove the load 11 from the corresponding module 10 a , 10 b and a buffer stopping system 19 designed to wedge the load 11 before removal.
- the removal system 18 and the buffer stopping system 19 constitute mechanical means enabling the parts to be moved and transferred between the cells and are advantageously located in the cold zones of the cells 2 , 3 , 4 .
- the running movement of the loads 11 inside the cells is performed by the loads 11 themselves which push one another forwards when a new load 11 is input.
- the treatment zone 14 thus does not contain any mechanical means for transfer or forward movement which are arranged only in the cold zones constituted by the input module 10 a and output module 10 b of the cells.
- the carbon enriching cell 3 comprises neutral gas injection phases alternating with cementing gas injection phases, transfer of the parts between the cells advantageously being performed at the same time as the neutral gas injection phases. It is therefore necessary to provide a sufficiently long neutral gas injection time slot and to actuate the different transfer and advancement means accordingly so as to be able to transfer all the loads 11 along the machine 1 .
- the cementing gases are thus confined only in the carbon enriching cell 3 and are not liable to contaminate the other cells 2 and 4 .
- the carburizing heating cell 2 comprises two standard modules 13 , the input orifice 16 and output orifice 17 of the cell 2 are parallel and located on the same side of the cell 2 with respect to the longitudinal axis 12 .
- the next carbon enriching cell 3 which comprises a single standard module 13 , is arranged in such a way that the longitudinal axis thereof 12 is parallel and oriented in the same direction as the longitudinal axis 12 of the previous cell.
- the input orifice 16 of the input module 10 a is therefore arranged facing the output orifice 17 of the output module 10 b of the previous cell 2 and the output orifice 17 of the output module 10 b of the cell 3 is arranged on the same side of the cell 3 as the input orifice 16 of the input module 10 a with respect to the longitudinal axis 12 .
- the carbon diffusion cell 4 which also comprises two standard modules 13 , is arranged parallel to the other two cells with its longitudinal axis 12 oriented in the same direction and aligned with the carburizing heating cell 2 .
- the input orifice 16 and output orifice 17 respectively of the input module 10 a and output module 10 b , are therefore arranged on the same side of the cell 4 with respect to the longitudinal axis 12 .
- the hardening cell 5 is connected to the output orifice 17 of the cell 4 and the input chamber 6 is connected to the input orifice 16 of the cell 2 .
- the arrangement of the machine 1 is therefore substantially in the shape of two L's facing one another, the parts moving in the cells in the direction of the arrows F 2 ( FIG. 1 ).
- the input module 10 a and output module 10 b of the cells 2 , 3 , 4 are advantageously arranged in such a way that they form connecting compartments 20 between two adjacent cells.
- the compartments 20 of the machine 1 can then comprise gas and pressure insulation systems 21 from one cell to the other during the treatment phases. They can also comprise check valve systems to control the gas flow between cells.
- the machine 1 comprises a pressure-tight door 21 arranged between the input module 10 a of the carburizing heating cell 2 and the input chamber 6 .
- the low pressure carburizing treatment machine 1 comprises the three cells 2 , 3 and 4 arranged in parallel manner one next to the other.
- the longitudinal axis 12 of the cell 3 is parallel and oriented in opposition with respect to the longitudinal axis 12 of the cells 2 and 4 .
- the input orifice 16 of the input module 10 a of the cell 3 is arranged facing the output module 10 b of the cell 2
- the output orifice 17 of the output module 10 b of the cell 3 is arranged on the other side of the cell 3 with respect to the longitudinal 12 axis, facing the input module 10 a of the cell 4 .
- the machine 1 can comprise a storage area 22 of the loads 11 at the beginning of the treatment cycle, awaiting input to the input chamber 6 , and a storage area 23 of the loads 11 at the end of the treatment cycle, downline from the hardening cell 5 and awaiting removal, for example to another site.
- the longitudinal axes 12 of the cells 2 and 3 are oriented in the same direction and the longitudinal axis 12 of the cell 4 is oriented in opposition with respect to the other two.
- the cells 3 and 4 are then offset with respect to the cell 2 .
- the machine 1 therefore presents a larger overall length.
- This particular arrangement substantially in the shape of a U, in particular enables the pumping systems 7 , 8 and 9 respectively associated with the cells 3 , 6 and 5 to be integrated into the machine 1 .
- the machine 1 can further comprise supervision, checking and/or control systems 24 adjoining the cells to check and/or control correct running of the carburizing treatment cycle.
- the alternative embodiment of the machine 1 represented in FIG. 6 differs from the alternative embodiment represented in FIG. 5 by the number of standard intermediate modules 13 of the cells 2 , 3 and 4 .
- the cells in fact respectively comprise three, two and three standard modules 13 arranged between the input module 10 a and output module 10 b . This results in an increase of the time spent by the parts in the corresponding cell.
- the lengths L 1 , L 2 and L 3 ( FIG. 1 ) respectively of the cells 2 , 3 and 4 can therefore be different depending on the number of standard modules 13 which they comprise.
- Such a machine 1 can adapt easily according to the place it is installed and can take a plurality of different configurations.
- the machine 1 therefore presents a completely reconfigurable architecture according to the applications, the size of the installation location, and the required treatment time, particularly due to the shape of the standard input module 10 a , output module 10 b and standard intermediate modules 13 of each cell 2 , 3 , 4 of the machine 1 . This results in particular in savings in time and space and gains in productivity.
- machines 1 represented in FIGS. 4, 5 and 6 in particular enable the storage areas 22 and 23 to be positioned close to one another. This results in simpler and faster handling of the loads 11 .
- the machine 1 can comprise two hardening cells, downline from the cell 4 , for example an oil hardening cell and a gas hardening cell or two gas hardening cells.
- the output module 10 b of the carbon diffusion cell 4 is different from the output modules 10 b of the other cells and comprises two output orifices 17 arranged on each wall parallel to the corresponding longitudinal axis 12 of the cell 4 .
- the two hardening cells are then connected to the same output module 10 b , the parts being input either to the first or to the second hardening cell, before being removed after treatment.
- the machine 1 can comprise a cleaning cell of the parts, between the input chamber 6 and the carburizing heating cell 2 , to prepare the parts designed to be cemented.
- the cleaning cell is a washing or degreasing machine working at atmospheric pressure or possibly in partial pressure in vapor phase.
- the machine 1 can comprise a convective preheating cell of the parts, upline from the carburizing heating cell 2 .
- the preheating cell is a convective preheating furnace designed to heat the parts to a temperature for example of about 300° C. to 500° C., before the latter are input to the carburizing heating cell 2 .
- Convective preheating makes the heating homogeneous and causes in particular oxidation of the parts and a good activation of the surfaces thereof.
- This phase is performed in air at atmospheric pressure, preferably with a little additional nitrogen.
- the preheating cell also results in time saving, as the parts are able to spend less time in the carburizing heating cell 2 after preheating thereof.
- the preheating cell is vacuum purged before the parts are transferred to the inside of the next cell.
- a pressure-tight door 21 has to be provided between the input module 10 a of the carburizing heating cell 2 and the preheating cell.
- the treatment machine 1 therefore presents the following advantages.
- the machine 1 is cold on the outside and non-polluting, on account of the cold walls of the treatment zones 14 of the cells 2 , 3 , and 4 .
- the cells 2 , 3 , 4 are of standard shape and of adaptable length due to the intermediate modules 13 and to the standard input module 10 a and output module 10 b , they can be installed in any existing machining workshop and in any mass production parts manufacturing installation. Productivity is therefore greatly improved.
- the flexibility of the installation also enables optional cells, in particular cleaning, preheating and tempering cells, to be inserted or not according to the production orders or the thermal treatments to be performed.
- the mechanical means for transferring and moving the parts between the cells are only located in the cold zones of the cells, in the input module 10 a and output module 10 b . This results in a better efficiency of the low pressure carburizing treatment.
- the parts to be treated can be formed by sets of parts arranged on a support.
- the cells can have any suitable shape.
- the transfer and closing means can be formed by any suitable means enabling tightness and predetermined pressure properties to be ensured between two adjacent cells.
- the cementing gas can be propane or any other hydrocarbon able to be associated with the temperatures of the carbon enriching cell 3 to treat the surface of the parts.
- the transfer and moving means located in the cold zone of the cells can be formed by any other removal system and a totally different buffer stopping system. Transfer between two adjacent cells being performed at predetermined pressure, the machine 1 can comprise additional means (not represented) for adjusting and controlling the pressure inside the compartments 20 in the course of treatment, if necessary, during the transfer phases.
- the machine can comprise additional transfer means (not represented) designed to transfer the parts to another finishing treatment machine for example (shot peening, rectification).
- the cells 2 to 4 can comprise heating equipment, a gas injection circuit and pumping connectors for vacuum pumps (not represented).
- thermochemical treatment machine 1 is then a vacuum carbonitriding treatment machine with a diffusion cell 4 into which a nitriding gas is injected.
- nitrogen enrichment can then be performed by introducing a gas such as ammoniac (NH 3 ) into the surface enrichment cell 3 and diffusion cell 4 at a rate to be determined according to the required result.
- a gas such as ammoniac (NH 3 )
- the cells also have the same configuration, with an input module, an output module and standard intermediate modules arranged between the modules so as to form a fully reconfigurable machine, according to the workshop, the applications and the required treatment time in the cells.
Abstract
Description
- The invention relates to a machine for thermochemical treatment of metal parts comprising at least one heating cell, one carbon enriching cell for enriching the surfaces of the parts to be treated, one carbon diffusion cell diffusing from the surface to the core of the parts, and at least one hardening cell, arranged in succession one after the other and having a length adapted to the duration of the treatment performed in each cell, the machine also comprising mechanical means for transferring and moving the parts from one cell to the next and insulating means to insulate the cells from one another during the different successive treatment phases.
- Numerous thermochemical treatment systems exist for carburizing and carbonitriding metal parts, in particular systems in the form of a case with a solid cement, systems in non-controlled atmosphere, systems in controlled atmosphere with a constant carbon potential, or low pressure systems with a pressure of about 5 mbar to 20 mbar, sometimes even up to 100 mbar.
- Carburizing and carbonitriding generally require a partial pressure of the carburizing gas, formed by a hydrocarbon, for example methane (CH4), acetylene (C2H2) or propane (C3H8), and possibly a nitriding gas, for example ammoniac (NH3). The carburizing operations, i.e. carburizing temperature-setting treatment, surface enrichment treatment and carbon diffusion treatment, are preferably executed under partial nitrogen pressure. To prevent any oxidation during the carburizing treatment and during transport to the hardening cell, the parts are not exposed to air at any time.
- The hardening operation, which follows the carburizing treatment, consists in cooling the parts rapidly. It is performed either in a bath of oils or molten salts or in a stirred gas at high pressure, such as nitrogen, helium or various mixtures of neutral gases such as carbon dioxide or hydrogen.
- These different operations, i.e. the different phases of the carburizing treatment, are generally performed in the same enclosure, hardening being performed in a separate cell.
- The Patent EP-A-0922778, in particular, describes a thermal treatment installation comprising a plurality of cells designed for thermal treatment of a set of metal parts. The cells are all connected to a central enclosure at the same pressure as the treatment cells. The parts are transferred from one cell to another by means of transport and handling rails. After carburizing in the corresponding cell, the carburized parts are transferred to the hardening cell passing via the central enclosure, meaning that there is no contact with the ambient air.
- Other installations are made up of independent cells connected to one another by a mobile cell whose function is to perform either the loading and transfer to the hardening cell operations, or the loading and transfer operations and at the same time hardening under pressurized gas.
- Other installations comprise a single partitioned cell of the “driven plate” type comprising an input chamber and a hardening under gas cell.
- In all cases of low pressure carburizing from 5 to 20 mbar, the phases of the carburizing treatment, i.e. at least a carburizing temperature-setting phase, a carbon enrichment phase of the surface of the parts, and a diffusion phase of the carbon from the surface to the core of the parts, are successively performed in one and the same cell or in a single partitioned cell comprising mechanical means for advancing and transferring the parts. The mechanical means are then situated in a hot zone.
- Another type of machine is described in U.S. Pat. No. 3,662,996. The machine is a conventional gas-carburizing machine at atmospheric pressure and comprises one cell for each phase of the carburizing treatment, i.e. a carburizing heating cell, a carbon enriching cell for enriching the surfaces of the parts to be treated and a carbon diffusion cell for diffusing the carbon from the surface to the core of the parts. The cells are arranged in succession one after the other and the parts are moved from one cell to another to receive the carburizing treatment, the length of a cell being previously defined according to the required treatment time in the cells.
- However, even if each phase of the treatment is performed in different cells, this type of machine can only function under certain conditions, in particular under high pressures. Moreover, the mechanical means for advancing and transferring the parts are situated in a hot zone, where the corresponding treatment is performed, and are not thermally insulated. Furthermore, this type of machine is difficult to integrate in existing production lines and the length of each cell can not easily be modulated according to the duration of the required treatment.
- The object of the invention is to remedy the above-mentioned drawbacks and to design a low pressure thermochemical carburizing or carbonitriding, treatment machine that is efficient, flexible and able to be easily adapted and integrated into mass production lines of parts.
- According to the invention, this object is achieved by the appended claims and, more particularly by the fact that the temperature-setting, carbon enrichment and carbon diffusion cells are of standard shape and each comprise a low pressure treatment zone situated between an input module and an output module, the input and output modules each forming a cold zone thermally insulated from the treatment zone of the corresponding cell, the mechanical means for transferring and moving being situated in the input and output modules of the cells and the output module of a cell being connected to the input module of the adjacent cell.
- Other advantages and features will become more clearly apparent from the following description of particular embodiments of the invention given as non-restrictive examples only and represented in the accompanying drawings, in which:
-
FIG. 1 schematically represents a top view of a first embodiment of a thermochemical treatment machine according to the invention. -
FIG. 2 schematically represents a top view of an alternative embodiment of a thermochemical treatment machine according toFIG. 1 . -
FIG. 3 represents a cell of the thermochemical treatment machine according toFIGS. 1 and 2 . - FIGS. 4 to 6 schematically represent top views of alternative embodiments of a thermochemical treatment machine according to the invention.
- With reference to FIGS. 1 to 6, the thermochemical treatment machine is a
machine 1 for low pressure carburizing treatment of metal parts under a vacuum. Themachine 1 comprises a plurality oftreatment cells 2 to 5 arranged in succession one after the other. Each cell corresponds to a particular phase of the low pressure carburizing treatment and presents a standard shape and a length L adaptable according to the duration of the treatment required in the cell. The manufacturing technique of the cells is that of cold-wall vacuum furnaces enabling an operating pressure comprised between 10−1 mbar and 30 mbar. - The
machine 1 also comprises means for moving and transferring the parts from one cell to the next and closing means designed to insulate one cell from the adjacent cells during the different phases of the carburizing treatment. Transfer of the parts between the cells is performed at a predetermined pressure, i.e. the carburizing pressure, of about 5 mbar to 20 mbar. Pumping systems keep the three cells at the same pressure, including during the transfer periods. - In
FIG. 1 , themachine 1 comprises in particular acarburizing heating cell 2. The object of the treatment performed in thecell 2 is to increase the temperature of the parts to the required carburizing temperature of about 880° C. to 1050° C. This phase is performed at the carburizing pressure of about 5 mbar to 20 mbar, preferably with nitrogen. In particular cases, the pressure can be increased up to 100 mbar. - Downline from the carburizing
heating cell 2, themachine 1 comprises acarbon enriching cell 3. The treatment performed in thecell 3 consists in enriching the surface of the parts in carbon or in carbon and nitrogen to increase the hardness of the parts after hardening. This enriching phase is preferably performed by injection of nitrogen or any other neutral gas at a temperature of about 880° C. to 1050° C. completed at regular intervals by injection of a cementing gas. The pressure in thecell 3 is for example about 5 mbar to 20 mbar depending on the cementing gas used. - After the
carbon enriching cell 3, the parts are transferred to a finalcarbon diffusion cell 4. The treatment performed in thecell 4 consists in diffusing the carbon into the thickness of the parts from the surface to the core of the parts, at the required depth of the cemented surface and the required percentage of carbon at the surface of the parts. This phase of the treatment is performed at the same pressure as that of the carburizingheating cell 2 andcarbon enriching cell 3. The temperature is adjusted, preferably between 880° C. and 1050° C., to enable a good penetration rate of the carbon into the parts and to obtain the optimum temperature of the parts before the hardening operation is performed. - The required treatment temperature inside the
carbon diffusion cell 4 is preferably different from the required treatment temperature inside the carburizingheating cell 2 andcarbon enriching cell 3. - Downline from the
cells 2 to 4, themachine 1 also comprises a hardeningcell 5 equipped with pressure-tight doors. For example, thecell 5 is a hardening cell performing gas quenching, oil quenching, salt bath quenching or quenching in any other system enabling the parts to be cooled at the required speed to obtain the required hardness. - In an alternative embodiment, not represented, the
machine 1 can comprise a tempering cell downline from thehardening cell 5. The tempering phase is performed at a temperature for example of about 200° C. to 300° C. - Upline from the
carburizing heating cell 2, themachine 1 also comprises aninput chamber 6 designed to store the parts waiting to enter the cell 2 (FIG. 1 ). In this case, care must be taken to perform vacuum purging in theinput chamber 6 so that the pressure in thechamber 6 is the same as that in thecarburizing heating cell 2, before the parts are input, and to ensure that the air is almost totally purged. - In the alternative embodiment represented in
FIG. 2 , themachine 1 comprises agas pumping system 7 connected by suitable means to thecarbon enriching cell 3 and designed to remove the gases present in thecells carbon enriching cell 3 contains cementing gases liable to contaminate thecells pumping system 7 therefore advantageously generates a gas flow in the direction of the arrows F1, from the carburizingheating cell 2 and thecarbon diffusion cell 4 to thecarbon enriching cell 3, which may be contaminated. - The
machine 1 can also comprise a firstindependent pumping system 8 of theinput chamber 6 and a secondindependent pumping system 9 of the hardeningcell 5. - In a general manner, the three
cells treatment cells - According to the invention, the
cells machine 1 are all shaped according to the same general model, of standard shape, adapted to each function (heating, enrichment and diffusion), and their length L is able to be modulated, which enables the treatment time of each cell to be adjusted precisely for a given treatment rate. Changing the rate notably enables different carburizing depths to be achieved. The length L of a cell is therefore proportional to the duration of the treatment performed in this cell. - Moreover, the temperatures can be adapted to enable precise adjustment of the characteristics to be obtained on the parts to be treated.
- In
FIG. 3 illustrating only thecarburizing heating cell 2 of themachine 1 ofFIGS. 1 and 2 , thecell 2 comprises aninput module 10 a whereby the parts to be treated enter, and anoutput module 10 b whereby the parts exit after treatment. Theinput module 10 a andoutput module 10 b are of standard shape and can each contain aload 11 of metal parts. - The
cell 2 presents alongitudinal axis 12 oriented from theinput module 10 a to theoutput module 10 b. Thelongitudinal axis 12 corresponds to the direction in which theloads 11 move, in the direction of the arrows F2, inside thecell 2. - Between the
input module 10 a and theoutput module 10 b, thecell 2 comprises two identical standardintermediate modules 13 of the same length. Fitting severalintermediate modules 13 between theinput module 10 a and theoutput module 10 b enables the length L1 of thecell 2 to be varied. For example, for thecarbon diffusion cell 4, the larger the number ofmodules 13 the greater the carburizing depth, at the same running rate of theloads 11 in thecell 4. - The
standard modules 13 of thecell 2 constitute a lowpressure treatment zone 14 within which the treatment proper to thecell 2 is performed. Thetreatment zone 14, preferably formed bystandard modules 13 with cold walls, is confined and insulated from theinput module 10 a andoutput module 10 b, which then constitute cold zones of thecell 2. The cold zones are thermally insulated from thetreatment zone 14 by means for example of thermally insulated cooleddoors 15 arranged between theinput module 10 a andoutput module 10 b and the confinedtreatment zone 14. - For example, cooling of a
door 15 is performed by means of a heat exchanger generating water circulation at the level of thedoor 15. - In
FIG. 3 , theinput module 10 a andoutput module 10 b are of standard shape having a substantially U-shaped cross-section, and each comprise an opening in connection with theadjacent module 13 and three walls closing the end of thecell 2. In the particular embodiment represented inFIG. 3 , theinput module 10 a comprises aninput orifice 16 situated on a wall of theinput module 10 a parallel to thelongitudinal axis 12 of thecell 2, and theoutput module 10 b comprises anoutput orifice 17 situated on a wall of theoutput module 10 b parallel to thelongitudinal axis 12 and situated on the same side of thecell 2 with respect to thelongitudinal axis 12. Theloads 11 of the parts enter and exit via the same side of thecell 2. - The
input module 10 a andoutput module 10 b each comprise for example anejection system 18 designed to push and remove theload 11 from the correspondingmodule buffer stopping system 19 designed to wedge theload 11 before removal. Theremoval system 18 and thebuffer stopping system 19 constitute mechanical means enabling the parts to be moved and transferred between the cells and are advantageously located in the cold zones of thecells - The running movement of the
loads 11 inside the cells is performed by theloads 11 themselves which push one another forwards when anew load 11 is input. Thetreatment zone 14 thus does not contain any mechanical means for transfer or forward movement which are arranged only in the cold zones constituted by theinput module 10 a andoutput module 10 b of the cells. - Placing the transfer means in the
input module 10 a and theoutput module 10 b, i.e. at the level of the cold zones of each cell, results in particular in a better efficiency of the carburizing treatment and a better conservation of the characteristics of the parts between the cells. - Moreover, the
carbon enriching cell 3 comprises neutral gas injection phases alternating with cementing gas injection phases, transfer of the parts between the cells advantageously being performed at the same time as the neutral gas injection phases. It is therefore necessary to provide a sufficiently long neutral gas injection time slot and to actuate the different transfer and advancement means accordingly so as to be able to transfer all theloads 11 along themachine 1. The cementing gases are thus confined only in thecarbon enriching cell 3 and are not liable to contaminate theother cells - In the particular embodiment represented in
FIGS. 1 and 2 , thecarburizing heating cell 2 comprises twostandard modules 13, theinput orifice 16 andoutput orifice 17 of thecell 2 are parallel and located on the same side of thecell 2 with respect to thelongitudinal axis 12. - The next
carbon enriching cell 3, which comprises a singlestandard module 13, is arranged in such a way that thelongitudinal axis thereof 12 is parallel and oriented in the same direction as thelongitudinal axis 12 of the previous cell. Theinput orifice 16 of theinput module 10 a is therefore arranged facing theoutput orifice 17 of theoutput module 10 b of theprevious cell 2 and theoutput orifice 17 of theoutput module 10 b of thecell 3 is arranged on the same side of thecell 3 as theinput orifice 16 of theinput module 10 a with respect to thelongitudinal axis 12. - Thus, the
carbon diffusion cell 4, which also comprises twostandard modules 13, is arranged parallel to the other two cells with itslongitudinal axis 12 oriented in the same direction and aligned with thecarburizing heating cell 2. Theinput orifice 16 andoutput orifice 17, respectively of theinput module 10 a andoutput module 10 b, are therefore arranged on the same side of thecell 4 with respect to thelongitudinal axis 12. The hardeningcell 5 is connected to theoutput orifice 17 of thecell 4 and theinput chamber 6 is connected to theinput orifice 16 of thecell 2. - The arrangement of the
machine 1, according toFIGS. 1 and 2 , is therefore substantially in the shape of two L's facing one another, the parts moving in the cells in the direction of the arrows F2 (FIG. 1 ). - Moreover, the
input module 10 a andoutput module 10 b of thecells compartments 20 between two adjacent cells. Thecompartments 20 of themachine 1 can then comprise gas andpressure insulation systems 21 from one cell to the other during the treatment phases. They can also comprise check valve systems to control the gas flow between cells. - For example, the
machine 1 comprises a pressure-tight door 21 arranged between theinput module 10 a of thecarburizing heating cell 2 and theinput chamber 6. - In the alternative embodiment represented in
FIG. 4 , the low pressure carburizingtreatment machine 1 comprises the threecells longitudinal axis 12 of thecell 3 is parallel and oriented in opposition with respect to thelongitudinal axis 12 of thecells input orifice 16 of theinput module 10 a of thecell 3 is arranged facing theoutput module 10 b of thecell 2, whereas theoutput orifice 17 of theoutput module 10 b of thecell 3 is arranged on the other side of thecell 3 with respect to the longitudinal 12 axis, facing theinput module 10 a of thecell 4. This particular orientation in opposition of theinput orifice 16 andoutput orifice 17 of themodules cell 3 in particular enables themachine 1 to be arranged with a general shape substantially in the form of an S, with thecells - Furthermore, the
machine 1 can comprise astorage area 22 of theloads 11 at the beginning of the treatment cycle, awaiting input to theinput chamber 6, and astorage area 23 of theloads 11 at the end of the treatment cycle, downline from the hardeningcell 5 and awaiting removal, for example to another site. - In the alternative embodiment of the
machine 1 represented inFIG. 5 , thelongitudinal axes 12 of thecells longitudinal axis 12 of thecell 4 is oriented in opposition with respect to the other two. Thecells cell 2. Themachine 1 therefore presents a larger overall length. This particular arrangement, substantially in the shape of a U, in particular enables thepumping systems cells machine 1. - The
machine 1 can further comprise supervision, checking and/orcontrol systems 24 adjoining the cells to check and/or control correct running of the carburizing treatment cycle. - The alternative embodiment of the
machine 1 represented inFIG. 6 differs from the alternative embodiment represented inFIG. 5 by the number of standardintermediate modules 13 of thecells standard modules 13 arranged between theinput module 10 a andoutput module 10 b. This results in an increase of the time spent by the parts in the corresponding cell. - Starting from the layout of the
machine 1 according toFIG. 5 , it suffices to disassemble theoutput module 10 b of thecell 2, to add the additionalstandard module 13 and to reposition theoutput module 10 b. Adding the additional standard modules, 13 is performed in the same way for thecells machine 1 according to the applications and the required treatment time. - In a general manner, for one and the same low
pressure carburizing machine 1, the lengths L1, L2 and L3 (FIG. 1 ) respectively of thecells standard modules 13 which they comprise. Such amachine 1 can adapt easily according to the place it is installed and can take a plurality of different configurations. Themachine 1 therefore presents a completely reconfigurable architecture according to the applications, the size of the installation location, and the required treatment time, particularly due to the shape of thestandard input module 10 a,output module 10 b and standardintermediate modules 13 of eachcell machine 1. This results in particular in savings in time and space and gains in productivity. - Moreover, the
machines 1 represented inFIGS. 4, 5 and 6 in particular enable thestorage areas loads 11. - In an alternative embodiment, not represented, the
machine 1 can comprise two hardening cells, downline from thecell 4, for example an oil hardening cell and a gas hardening cell or two gas hardening cells. In this case, theoutput module 10 b of thecarbon diffusion cell 4 is different from theoutput modules 10 b of the other cells and comprises twooutput orifices 17 arranged on each wall parallel to the correspondinglongitudinal axis 12 of thecell 4. The two hardening cells are then connected to thesame output module 10 b, the parts being input either to the first or to the second hardening cell, before being removed after treatment. - In another alternative embodiment that is not represented, the
machine 1 can comprise a cleaning cell of the parts, between theinput chamber 6 and thecarburizing heating cell 2, to prepare the parts designed to be cemented. For example, the cleaning cell is a washing or degreasing machine working at atmospheric pressure or possibly in partial pressure in vapor phase. - In another alternative embodiment, not represented, the
machine 1 can comprise a convective preheating cell of the parts, upline from thecarburizing heating cell 2. For example, the preheating cell is a convective preheating furnace designed to heat the parts to a temperature for example of about 300° C. to 500° C., before the latter are input to thecarburizing heating cell 2. Convective preheating makes the heating homogeneous and causes in particular oxidation of the parts and a good activation of the surfaces thereof. This phase is performed in air at atmospheric pressure, preferably with a little additional nitrogen. The preheating cell also results in time saving, as the parts are able to spend less time in thecarburizing heating cell 2 after preheating thereof. Once the preheating phase has been completed, the preheating cell is vacuum purged before the parts are transferred to the inside of the next cell. - In the case of use of a convective preheating cell, a pressure-
tight door 21 has to be provided between theinput module 10 a of thecarburizing heating cell 2 and the preheating cell. - Whatever the embodiment of the
machine 1 described above, thetreatment machine 1 therefore presents the following advantages. Themachine 1 is cold on the outside and non-polluting, on account of the cold walls of thetreatment zones 14 of thecells cells intermediate modules 13 and to thestandard input module 10 a andoutput module 10 b, they can be installed in any existing machining workshop and in any mass production parts manufacturing installation. Productivity is therefore greatly improved. The flexibility of the installation also enables optional cells, in particular cleaning, preheating and tempering cells, to be inserted or not according to the production orders or the thermal treatments to be performed. - Furthermore, the mechanical means for transferring and moving the parts between the cells are only located in the cold zones of the cells, in the
input module 10 a andoutput module 10 b. This results in a better efficiency of the low pressure carburizing treatment. - The invention is not limited to the different embodiments described above. In particular, the parts to be treated can be formed by sets of parts arranged on a support. The cells can have any suitable shape. The transfer and closing means can be formed by any suitable means enabling tightness and predetermined pressure properties to be ensured between two adjacent cells. The cementing gas can be propane or any other hydrocarbon able to be associated with the temperatures of the
carbon enriching cell 3 to treat the surface of the parts. - The transfer and moving means located in the cold zone of the cells can be formed by any other removal system and a totally different buffer stopping system. Transfer between two adjacent cells being performed at predetermined pressure, the
machine 1 can comprise additional means (not represented) for adjusting and controlling the pressure inside thecompartments 20 in the course of treatment, if necessary, during the transfer phases. - After the tempering cell if the latter is installed, the machine can comprise additional transfer means (not represented) designed to transfer the parts to another finishing treatment machine for example (shot peening, rectification).
- The
cells 2 to 4 can comprise heating equipment, a gas injection circuit and pumping connectors for vacuum pumps (not represented). - In another alternative embodiment, not represented, carbonitriding treatment may be applied in the
cells thermochemical treatment machine 1 is then a vacuum carbonitriding treatment machine with adiffusion cell 4 into which a nitriding gas is injected. For example, nitrogen enrichment can then be performed by introducing a gas such as ammoniac (NH3) into thesurface enrichment cell 3 anddiffusion cell 4 at a rate to be determined according to the required result. - Operation of the machine remains the same as before, with the parts to be treated passing successively in each treatment cell. The cells also have the same configuration, with an input module, an output module and standard intermediate modules arranged between the modules so as to form a fully reconfigurable machine, according to the workshop, the applications and the required treatment time in the cells.
Claims (16)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0408723A FR2874079B1 (en) | 2004-08-06 | 2004-08-06 | THERMOCHEMICAL CEMENT TREATMENT MACHINE |
FR0408723 | 2004-08-06 | ||
PCT/FR2005/002018 WO2006024780A1 (en) | 2004-08-06 | 2005-08-02 | Low pressure thermochemical treatment machine |
Publications (1)
Publication Number | Publication Date |
---|---|
US20080084011A1 true US20080084011A1 (en) | 2008-04-10 |
Family
ID=34947522
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/658,261 Abandoned US20080084011A1 (en) | 2004-08-06 | 2005-08-02 | Low Pressure Thermochemical Treatment Machine |
Country Status (6)
Country | Link |
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US (1) | US20080084011A1 (en) |
EP (1) | EP1786944B1 (en) |
JP (1) | JP5005537B2 (en) |
DE (1) | DE602005005343T2 (en) |
FR (1) | FR2874079B1 (en) |
WO (1) | WO2006024780A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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CN103048248B (en) * | 2012-12-11 | 2015-08-26 | 哈尔滨医科大学 | The diffusion cell of adjustable effective diffusion area and acceptance pool volume |
PL228603B1 (en) * | 2015-02-04 | 2018-04-30 | Seco/Warwick Spolka Akcyjna | Multi-chamber furnace for vacuum carburizing and hardening of toothed wheels, rollers, rings, and similar parts |
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US3662996A (en) * | 1970-03-23 | 1972-05-16 | Holcroft & Co | Multi-chamber carburizing apparatus |
US4340361A (en) * | 1979-06-14 | 1982-07-20 | Kubota, Ltd. | Apparatus for heat-treating cast iron pipes |
US5402994A (en) * | 1992-01-15 | 1995-04-04 | Aichelin Gmbh | Device for heat-treating metal workpieces |
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US6451137B1 (en) * | 1999-11-17 | 2002-09-17 | Etudes Et Constructions Mecaniques | Method of quenching after a low-pressure carburization |
US20030168125A1 (en) * | 2001-02-23 | 2003-09-11 | Aymeric Goldsteinas | Low-pressure carburising method |
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FR2487492B1 (en) * | 1980-07-25 | 1987-07-17 | Bmi | OVEN FOR CONTINUOUS THERMAL OR THERMOCHEMICAL TREATMENT OF METALS |
JPS5765961U (en) * | 1980-10-03 | 1982-04-20 | ||
JPS60141863A (en) * | 1983-12-28 | 1985-07-26 | Santetsuku:Kk | Method and device for continuous heat treatment |
DD243050A1 (en) * | 1985-11-27 | 1987-02-18 | Hochvakuum Dresden Veb | RECIPIENT FOR VACUUM PLANTS |
JP2958710B2 (en) * | 1990-11-28 | 1999-10-06 | 本田技研工業株式会社 | Gas soft nitriding of crankshaft |
EP0621904B1 (en) * | 1992-01-15 | 1997-04-09 | Aichelin Gmbh | Device for heat-treating metal workpieces |
JP3490791B2 (en) * | 1994-12-20 | 2004-01-26 | 光洋サーモシステム株式会社 | Multi-chamber heat treatment furnace |
JP3448789B2 (en) * | 1995-01-20 | 2003-09-22 | 同和鉱業株式会社 | Gas carburizing method |
DE10021583A1 (en) * | 2000-05-04 | 2001-11-15 | Ald Vacuum Techn Ag | Assembly to carburize and harden steel workpiece charges has structured pressures in the transport tunnel and heating chambers and carburizing and quenching chambers to reduce energy costs |
ATE362000T1 (en) * | 2001-01-26 | 2007-06-15 | Ipsen Int Gmbh | DEVICE AND METHOD FOR TRANSPORTING METAL WORKPIECES AND SYSTEM FOR THE HEAT TREATMENT OF THESE WORKPIECES |
JP2003042664A (en) * | 2001-07-31 | 2003-02-13 | Daido Steel Co Ltd | Vacuum heating furnace |
JP2003183728A (en) * | 2001-12-14 | 2003-07-03 | Jh Corp | Vacuum heat-treatment apparatus |
US6902635B2 (en) * | 2001-12-26 | 2005-06-07 | Nitrex Metal Inc. | Multi-cell thermal processing unit |
JP2004091900A (en) * | 2002-09-03 | 2004-03-25 | Toyota Motor Corp | Gas carburization method and gas carburization system |
-
2004
- 2004-08-06 FR FR0408723A patent/FR2874079B1/en not_active Expired - Fee Related
-
2005
- 2005-08-02 US US11/658,261 patent/US20080084011A1/en not_active Abandoned
- 2005-08-02 JP JP2007524374A patent/JP5005537B2/en active Active
- 2005-08-02 WO PCT/FR2005/002018 patent/WO2006024780A1/en active IP Right Grant
- 2005-08-02 DE DE602005005343T patent/DE602005005343T2/en active Active
- 2005-08-02 EP EP05796230A patent/EP1786944B1/en active Active
Patent Citations (6)
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US3662996A (en) * | 1970-03-23 | 1972-05-16 | Holcroft & Co | Multi-chamber carburizing apparatus |
US4340361A (en) * | 1979-06-14 | 1982-07-20 | Kubota, Ltd. | Apparatus for heat-treating cast iron pipes |
US5402994A (en) * | 1992-01-15 | 1995-04-04 | Aichelin Gmbh | Device for heat-treating metal workpieces |
US5868871A (en) * | 1996-06-06 | 1999-02-09 | Dowa Mining Co., Ltd. | Method and apparatus for carburizing, quenching and tempering |
US6451137B1 (en) * | 1999-11-17 | 2002-09-17 | Etudes Et Constructions Mecaniques | Method of quenching after a low-pressure carburization |
US20030168125A1 (en) * | 2001-02-23 | 2003-09-11 | Aymeric Goldsteinas | Low-pressure carburising method |
Also Published As
Publication number | Publication date |
---|---|
EP1786944B1 (en) | 2008-03-12 |
DE602005005343T2 (en) | 2009-03-19 |
DE602005005343D1 (en) | 2008-04-24 |
JP2008509282A (en) | 2008-03-27 |
FR2874079A1 (en) | 2006-02-10 |
EP1786944A1 (en) | 2007-05-23 |
JP5005537B2 (en) | 2012-08-22 |
FR2874079B1 (en) | 2008-07-18 |
WO2006024780A1 (en) | 2006-03-09 |
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