Classifications

• • 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
  • C21D11/00—Process control or regulation for heat treatments
• • 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
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material

Definitions

• the present invention relates to a system for heat treatment of parts of any shape, preferably parts for the mechanical industry such as in particular parts for the automotive industry.
• French patent 86 01 913 filed on February 12, 1986 and published under the number 2,594,102 by the present holder describes an installation for thermochemical treatment of parts in particular for the mechanical industry, which is characterized in that it includes an airlock. transfer of parts under a controlled atmosphere, a plurality of parts processing modules such as in particular preheating modules, thermochemical treatment modules, quenching modules, all these modules being connected to the transfer airlock, a loading airlock, an unloading airlock and a parts handling robot placed in the transfer airlock to ensure successive transfers of the parts to be treated to the different modules.
• parts processing modules such as in particular preheating modules, thermochemical treatment modules, quenching modules, all these modules being connected to the transfer airlock, a loading airlock, an unloading airlock and a parts handling robot placed in the transfer airlock to ensure successive transfers of the parts to be treated to the different modules.
• French patent 87 13 217 filed on September 24, 1987 by the present holder also describes an automatic installation of fast thermochemical treatment of a load made up of parts intended in particular for the mechanical industry, which includes a plurality of treatment modules such as in particular induction preheating module, thermochemical treatment modules, quenching module, a means for loading and unloading of the pieces stacked in columns and a means for transferring said columns of pieces between the different treatment modules.
• a plurality of treatment modules such as in particular induction preheating module, thermochemical treatment modules, quenching module, a means for loading and unloading of the pieces stacked in columns and a means for transferring said columns of pieces between the different treatment modules.
• the present invention proposes to apply the installations described above to treatments of parts in particular of mechanical parts, with a view to obtaining the results mentioned above, these treatments being characterized by the following operations: heating , temperature maintenance and controlled cooling.
• This treatment may include degassing. Indeed, even if the surface of the product is free of deposits, it may contain adsorbed gaseous species and by raising the temperature, placing under vacuum and maintaining under vacuum for a sufficient time, it is possible to significantly reduce the content. of these gaseous species in the product finally obtained;
• Degreasing can also be carried out, which can be carried out by means of rapid heating under a gaseous stream of hydrogen and water vapor.
• the treatments concerning the maintenance of the surface finish of the treated parts may include other operations such as blueing, etc.
• the invention therefore proposes to carry out operations which make it possible to avoid these drawbacks in order to maintain the dimensional stability of the parts treated.
• These treatments can be as follows: - homogenization annealing at a temperature below the temperature at which the ferrite completes to transform into austenite during heating, and maintenance at this temperature - stress relief annealing performed by maintaining at a temperature of the order of 650 ° C. for a period of one hour relaxation annealing carried out by heating to a temperature of the order of 100 to 200 ° C. with maintenance at this temperature then slow cooling and - Stabilization annealing carried out by heating to a temperature at which the austenite begins to form, for example at around 200 ° C., this heating being followed by rapid cooling.
• This treatment essentially involves a softening annealing.
• the different types of treatment which have just been mentioned in order to maintain the quality of the products which are to be or have undergone heat treatment essentially comprise three types of operation: heating, temperature maintenance and controlled cooling, which, according to the invention, are carried out on an installation of the type described in the patent applications cited above.
• the heating necessary for annealing or tempering can be carried out in the induction heating chambers provided in these installations or in one or more treatment chambers in the case of specific temperature cycles.
• thermochemical treatment chambers Keeping at temperature can be performed according to the cycles concerned, either: - in the induction heating chamber - in the thermochemical treatment chambers if the maintenance takes place at a temperature at which the ferrite is transformed into austenite during heating - in rooms with suitable temperature, when the temperature is maintained at a temperature different from that indicated above.
• the cooling can be carried out either in the quenching chamber, or by convection, by radiation alone or using a neutral gas at a suitable temperature or by any other suitable means.
• thermochemical treatment When the treatment is preliminary or consecutive to the thermochemical treatment, it can be carried out directly and automatically in the installation without it being necessary to carry out a removal of the parts from the latter.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Heat Treatment Of Articles (AREA)
• Furnace Details (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9373471

Family Applications (1)

Country Status (11)

Families Citing this family (2)

Citations (5)

• 1988
  • 1988-12-27 FR FR8817245A patent/FR2640999A1/fr active Pending
• 1989
  • 1989-12-06 CA CA002004761A patent/CA2004761A1/fr not_active Abandoned
  • 1989-12-22 ES ES89403635T patent/ES2016785A4/es active Pending
  • 1989-12-22 DE DE198989403635T patent/DE376832T1/de active Pending
  • 1989-12-22 KR KR1019900701898A patent/KR910700358A/ko not_active Application Discontinuation
  • 1989-12-22 JP JP2501754A patent/JPH03503187A/ja active Pending
  • 1989-12-22 DD DD89336256A patent/DD290665A5/de not_active IP Right Cessation
  • 1989-12-22 EP EP89403635A patent/EP0376832A1/fr not_active Withdrawn
  • 1989-12-22 WO PCT/FR1989/000675 patent/WO1990007583A1/fr unknown
  • 1989-12-26 CN CN89109569A patent/CN1043958A/zh active Pending
• 1991
  • 1991-09-27 GR GR90300153T patent/GR900300153T1/el unknown

Patent Citations (5)

Non-Patent Citations (2)

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