JP5270074B2 - Heat treatment apparatus and heat treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment apparatus which can heat-treat an object to be heat-treated without giving a great drop impact on the object to be heat-treated. <P>SOLUTION: This heat treatment apparatus comprises: a mesh belt conveyor 11 for transporting the object to be heat-treated into a heating furnace 3 for use in tempering; roller chains 28 on both sides of the conveyor 11; a roller chain conveyor 27 which has shorter transportation distance than the mesh belt conveyor 11 on the bottom side of the mesh belt conveyor 11; and a plurality of plates 29 which are attached to the roller chains 28 so as to prevent the object to be heat-treated from dropping from the mesh belt conveyor 11. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a heat treatment apparatus and a heat treatment method used when, for example, heat treatment such as quenching and tempering is performed on a bearing ring material or a rolling element material of a rolling bearing.

  Generally, the bearing rings and rolling elements of rolling bearings are made of steel that has been quenched and tempered, and heat treatment equipment used when quenching and tempering steel materials that are used as bearing ring materials and rolling element materials. There are a type called a batch type and a type called a continuous type. Among these, the latter heat treatment apparatus is a quenching heating furnace for quenching the object to be heat treated, a tempering heating furnace provided at a subsequent stage of the quenching heating furnace, and the tempering heating furnace and quenching furnace. A quenching oil tank provided between the heating furnace and a cleaning device provided between the quenching oil tank and the tempering heating furnace is provided. Further, this type of heat treatment apparatus is configured to first heat the object to be heat-treated into the heating furnace for quenching, and to heat the object to be heat-treated conveyed by the first belt conveyor into the heating furnace for quenching. A chute to be put into the oil tank, a second belt conveyor for pulling up the material to be heat-treated from the chute into the quenching oil tank, and a material to be heat-treated from the quenching oil tank by the second belt conveyor And a third belt conveyor for transporting the cleaning material to the cleaning device, and the heat-treated material cleaned by the cleaning device is transported into the tempering heating furnace by the third belt conveyor or the fourth belt conveyor. (For example, refer to Patent Document 1).

In such a continuous heat treatment apparatus, it becomes difficult to perform quenching and tempering continuously when the object to be heat-treated conveyed into the tempering heating furnace falls from the belt conveyor due to vibration or the like. Therefore, in order to prevent the object to be heat-treated conveyed into the tempering heating furnace from dropping from the belt conveyor, a mesh belt with a side plate is often used as the conveyor belt of the belt conveyor.
JP 2000-356332 A

  However, when a mesh belt with a side plate is used as the conveyor belt of the belt conveyor that conveys the heat-treated material into the tempering heating furnace, the roller diameter of the conveying roller on which the mesh belt is stretched is adjusted to the length of the side plate. It needs to be bigger. For this reason, there has been a problem that the drop distance of the object to be heat-treated falling from the end portion of the tempering belt conveyor onto the other conveying device becomes long, and a large drop impact is applied to the object to be heat-treated.

  Moreover, in the above-described conventional heat treatment apparatus, since the material to be heat-treated pulled up from the quenching oil tank falls from the second belt conveyor onto the third belt conveyor, a large drop impact is applied to the material to be heat-treated, There was a problem that the object to be heat-treated was easily damaged. Furthermore, in the above-described conventional heat treatment apparatus, the atmospheric gas supplied into the quenching heating furnace leaks more than necessary from the entrance of the quenching heating furnace. For this reason, it is necessary to always supply a large amount of atmospheric gas into the quenching heating furnace, and it is difficult to suppress the supply amount of the atmospheric gas supplied into the quenching heating furnace. In addition, when the object to be heat-treated pulled up from the quenching oil tank is transferred to the tempering heating furnace through the cleaning device, the cleaning liquid component and oil accompanying the object to be heat-treated adhere to the inner surface of the tempering heating furnace. May cause deterioration of the heat insulating material forming the tempering heating furnace.

  The present invention has been made paying attention to the above-described problems, and an object of the present invention is to provide a heat treatment apparatus and a heat treatment method capable of performing heat treatment of a heat-treated object without giving a large drop impact to the heat-treated object. There is. In addition, a second object of the present invention is to provide a heat treatment apparatus and a heat treatment capable of suppressing a large drop impact from being applied to the heat treatment object when the heat treatment object pulled up from the quenching oil tank is transported to the next process. It is to provide a method. The third object of the present invention is to provide a heat treatment apparatus and a heat treatment method capable of reducing the amount of leakage of atmospheric gas leaking from the inlet of the heating furnace. A fourth object of the present invention is to provide a heat treatment apparatus and a heat treatment method capable of suppressing deterioration of a heat insulating material forming a heating furnace.

In order to solve the above-described problems, a heat treatment apparatus according to a first aspect of the present invention is a heat treatment apparatus including a heating furnace and a mesh belt conveyor that conveys an object to be heat treated in the heating furnace. A plurality of roller chain conveyors having roller chains on both sides of the belt conveyor and having a shorter conveying distance than the mesh belt conveyor are provided on the lower surface side of the mesh belt conveyor, and a plurality of heat-treated materials are prevented from dropping from the mesh belt conveyor. A drop prevention plate is provided on the roller chain conveyor, and the diameter of the transport roller for the mesh belt conveyor disposed on the outlet side of the heating furnace is set to the sprocket for the roller chain conveyor or the transport for the roller chain conveyor. It is characterized by being smaller than the diameter of the roller .

A heat treatment apparatus according to a second aspect of the present invention includes a quenching heating furnace, a tempering heating furnace provided at a subsequent stage of the quenching heating furnace, the tempering heating furnace, and the quenching heating. A quenching oil tank provided between the furnace, a cleaning device provided between the quenching oil tank and the tempering heating furnace, and a first heat transfer object to be transferred into the quenching heating furnace. A belt conveyor, a chute for feeding the material to be heat-treated conveyed into the quenching heating furnace by the first belt conveyor into the quenching oil tank, and a chute introduced into the quenching oil tank from the chute In a heat treatment apparatus comprising: a second belt conveyor that pulls up the object to be heat-treated; and a third belt conveyor that conveys the object to be heat-treated pulled up from the quenching oil tank to the cleaning device by the second belt conveyor. , The cover pulled up from the quenching oil tank Passes treated with vicinity of the upper surface of said third belt conveyor to the belt conveyor to be heat-treated transfer mechanism provided near the terminal end of the second conveyor belt, the heat-treated product delivery mechanism, said third belt A lower roller provided in the vicinity of the upper surface of the conveyor, an upper roller provided above the lower roller, and a material to be heat-treated that has been slackened between the upper roller and the lower roller. It has a support belt .

In the heat treatment apparatus according to the second aspect of the present invention, the object to be heat-treated to the tempering furnace may be conveyed by a third belt conveyor, or a fourth belt conveyor may be newly provided. In order to suppress the internal deterioration of the tempering heating furnace, it is preferable to newly provide the belt conveyor No. 4 .

A heat treatment method according to a third aspect of the present invention is characterized in that heat treatment is performed on an object to be heat treated using the heat treatment apparatus according to claim 1 or 2 .

In the heat treatment apparatus according to the first invention, it is possible to prevent the object to be heat-treated conveyed in the tempering heating furnace from dropping from the mesh belt conveyor by the fall prevention plate provided on the roller chain conveyor, Since it is not necessary to use a mesh belt with side plates as the conveyor belt of the mesh belt conveyor or to use a roller having a large roller diameter as the conveyor roller for driving the conveyor belt, it gives a large drop impact to the object to be heat treated. Therefore, the heat treatment of the object to be heat treated can be performed. In particular, since the roller diameter of the conveying roller arranged on the outlet side of the heating furnace is made smaller than the roller diameter of the sprocket (or conveying roller) of the roller chain conveyor, the falling distance of the object to be heat treated can be shortened. It can suppress further that a drop impact is added.

In the heat treatment apparatus according to the second invention, the object to be heat-treated pulled up from the quenching oil tank is delivered to the third belt conveyor in the vicinity of the upper surface thereof. When dropping from the second belt conveyor onto the third belt conveyor, a large drop impact can be suppressed from being applied to the object to be heat treated. In particular, the object to be heat-treated falls between the second belt conveyor and the object to be heat-treated object supporting belt of the object to be heat-treated delivery mechanism, and moves to the vicinity of the third belt conveyor and then drops onto the third belt conveyor. Therefore, since a large drop impact is not applied to the object to be heat treated, the object to be heat treated can be prevented from being damaged by the drop impact.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1st Embodiment of the heat processing apparatus which concerns on this invention is shown in FIGS. A heat treatment apparatus 1 shown in FIG. 1 includes a quenching heating furnace 2 for quenching an object to be heat treated, a tempering heating furnace 3 provided in a subsequent stage of the quenching heating furnace 2, and the tempering heating. A quenching oil tank 4 provided between the furnace 3 and the quenching heating furnace 2, and a washing water shower apparatus 5 as a cleaning apparatus provided between the quenching oil tank 4 and the tempering heating furnace 3; An atmosphere gas (for example, a mixed gas of RX gas and enriched gas) is supplied from the atmosphere gas supply pipe 6 into the quenching heating furnace 2.

  Further, the heat treatment apparatus 1 includes a first belt conveyor 7 that conveys an object to be heat-treated into a quenching heating furnace 2, and the first belt conveyor 7 transports the workpiece to the quenching heating furnace 2. The object to be heat-treated is heated to a high temperature (for example, 720 ° C. or higher) and then charged into the quenching oil tank 4 from a chute 8 provided at the rear end of the quenching heating furnace 2. Further, the heat treatment apparatus 1 has a second belt conveyor 9 that pulls up the material to be heat-treated from the chute 8 into the quenching oil tank 4, and the heat treatment that is pulled up from the quenching oil tank 4 by the second belt conveyor 9. And a third belt conveyor 10 that conveys the product to the cleaning water shower device 5, and the heat-treated material cleaned by the cleaning water shower device 5 is tempered by the fourth belt conveyor 11. It is designed to be conveyed.

The quenching heating furnace 2 has an inlet at the left end in FIG. 1, and an air jet nozzle 12 (see FIG. 2) for forming an air curtain is provided at the entrance of the quenching heating furnace 2. It is provided above the first belt conveyor 7. A cover member 13 that covers the air ejection nozzle 12 is provided on the upper and side portions of the air ejection nozzle 12.
The first belt conveyor 7 has a plurality of conveying rollers 7a (see FIG. 1) and a mesh belt 7b as a conveying belt stretched over these conveying rollers 7a, and on the lower surface side of the mesh belt 7b. Is provided with a flame curtain forming burner 14 (see FIG. 2) for forming a flame curtain at the entrance of the quenching heating furnace 2.

  The second belt conveyor 9 has a plurality of conveying rollers 9a (see FIG. 1) and a mesh belt 9b as a conveying belt stretched over these conveying rollers 9a. In the vicinity of the end portion, there is provided a workpiece to be treated delivery mechanism 16 (see FIG. 3) that delivers the workpiece to be treated W pulled up from the quenching oil tank 4 to the third belt conveyor 10 in the vicinity of the upper surface thereof. The mesh belt 9b is provided with a plurality of work support members 15 (see FIG. 1) for supporting the work on the inclined surface in the middle of pulling up at a constant pitch. In order to prevent the workpiece from falling off, a side plate (not shown) is provided.

  A workpiece transfer mechanism 16 includes a lower roller 17 provided near the upper surface of the third belt conveyor 10, an upper roller 18 provided above the lower roller 17, and the upper roller 18 and the lower roller 17. An endless heat-treated object support belt 19 that is stretched in a slack state, and a belt separating mechanism 20 that separates the heat-treated object support belt 19 from the terminal end of the second belt conveyor 9; The workpiece support belt 19 is formed to have substantially the same width as the mesh belt 9a of the second belt conveyor 9, and the upper roller 18 or the lower roller 17 has the same speed as that of the second belt conveyor 9 in FIG. It is driven in the direction of the middle arrow.

  The belt separating mechanism unit 20 swings a fluid pressure cylinder 21 such as an air cylinder, a rod-shaped roller support member 22 having an upper end connected to a piston rod of the fluid pressure cylinder 21, and a center portion of the roller support member 22. The lower roller 17 is supported by the lower end portion of the roller support member 22. The roller support member 22 is urged clockwise in the drawing by a tension spring 24 (see FIG. 8).

The tempering heating furnace 3 has a heat insulating material 25 (see FIG. 4), and the inner surface portion and the outer surface portion of the tempering heating furnace 3 are made of a metal having corrosion resistance and heat resistance (for example, stainless steel such as SUS304). The cover plate 26 is covered.
Further, the tempering heating furnace 3 has a gas burner (not shown) in the furnace, and the heat-treated material conveyed into the tempering heating furnace 3 by the fourth belt conveyor 11 is caused by the combustion heat of the gas burner. For example, since heating is performed in a temperature atmosphere of 300 ° C. or less, preferably 150 to 190 ° C., deformation of the inner surface portion is suppressed.

  As shown in FIG. 4, the fourth belt conveyor 11 includes a plurality of conveying rollers 11a and an endless mesh belt 11b stretched over these conveying rollers 11a. 11 (mesh belt conveyor) is provided with a roller chain conveyor 27 (see FIG. 5) having a shorter conveying distance than the fourth belt conveyor 11.

  The roller chain conveyor 27 has roller chains 28 (see FIG. 5) on both sides of the fourth belt conveyor 11. These roller chains 28 are driven and driven by driving one of a plurality of sprockets (or conveying rollers) 30 (see FIGS. 4 and 6) by a drive motor (not shown). In the chain 28, a plurality of fall prevention plates 29 (see FIGS. 6 and 7) are provided in order to prevent the object to be heat-treated conveyed into the tempering heating furnace 3 from falling on the fourth belt conveyor 11. It is attached.

  The mesh belt 11b of the belt conveyor 11 is driven by a frictional force generated between the mesh belt 11b and the roller chain conveyor 27 due to its own weight, and travels at the same speed as the roller chain conveyor 27. Thereby, since a speed difference does not arise between the belt conveyor 11 and the roller chain conveyor 27, abrasion of both conveyors can be prevented.

  In such a configuration, when the object to be heat-treated is transported into the quenching heating furnace 2 by the first belt conveyor 7, the object to be heat-treated transported into the quenching heating furnace 2 is here at a predetermined temperature. Is heated to a quenching oil tank 4 through a chute 8. And if the to-be-heated material thrown into the quenching oil tank 4 is pulled up from the quenching oil tank 4 by the 2nd belt conveyor 9, and is further conveyed by the 3rd belt conveyor 10 to the washing water shower apparatus 5, it will wash | clean. The material to be heat-treated conveyed to the water shower device 5 is washed here, and then falls from the third belt conveyor 10 onto the fourth belt conveyor 11 and is tempered by the fourth belt conveyor 11. 3 is conveyed. At this time, when the mesh belt 11b of the fourth belt conveyor 11 travels in the direction of the arrow in FIG. 6, the roller chain 28 of the roller chain conveyor 27 is driven at the same speed as the mesh belt 11b in the same direction.

  Therefore, in the above-described embodiment, the material to be heat-treated conveyed into the tempering heating furnace 3 can be prevented from falling from the fourth belt conveyor 11 by the fall prevention plate 29 provided on the roller chain 28. As a result, it is not necessary to use a mesh belt with a side plate as the conveying belt of the fourth belt conveyor 11 or to use a large roller diameter as a conveying roller for driving the conveying belt. Since the fall distance of the to-be-processed object falling on the next conveyance apparatus from the terminal part of 11 can be shortened, it can suppress that a big drop impact is added to a to-be-processed object.

Further, _(see FIG. 5) forces Bone pitch (center distance) P _MB mesh belt 11b because smaller than the pitch P _R of the roller chain 28 _(see FIG. 6), placed at the outlet side of the tempering heating furnace 3 The roller diameter of the transport roller 11a ₁ (refer to FIG. 6) can be made smaller than the roller diameter of the sprocket (or transport roller) 30 described above, so that the end of the fourth belt conveyor 11 can be moved onto the next transport device. Since the drop distance of the object to be heat-treated falling can be shortened, it can be further suppressed that a large drop impact is applied to the object to be heat-treated.

Further, the mesh roller 11b between the transport roller 11a ₁ disposed on the exit side of the belt conveyor 11 and the next transport roller 11a ₂ (see FIG. 6) is disposed on the entrance side of the tempering heating furnace 3. Inclined at an angle of 45 degrees or less (preferably around 0 degrees) with respect to the mesh belt 11b between the conveyor belt 11a ₁ disposed on the exit side of the belt conveyor 11 and the return portion of the mesh belt 11b is a hairpin Since it becomes a shape, the fall distance of the to-be-processed object falling on the next conveyance apparatus from the terminal part of the 4th belt conveyor 11 can be made still shorter.

  In the above-described embodiment, when the heat-treated material heated to a predetermined temperature in the quenching heating furnace 2 is introduced into the quenching oil tank 4 through the chute 8, it is introduced into the quenching oil tank 4. The object to be heat treated is pulled up from the quenching oil tank 4 by the second belt conveyor 9 and then falls onto the third belt conveyor 10. At this time, as shown in FIG. 3, the workpiece W is held between the mesh belt 9 b of the second belt conveyor 9 and the workpiece support belt 19 of the workpiece delivery mechanism 16 while being held by the third belt. After moving to the vicinity of the conveyor 10, it falls onto the third belt conveyor 10. As a result, when the object to be heat-treated pulled up from the quenching oil tank 4 falls on the third belt conveyor 10, a large drop impact is not applied to the object to be heat-treated. Can be prevented.

  Further, since the workpiece support belt 19 of the workpiece delivery mechanism 16 is driven and driven at substantially the same speed as the mesh belt 9b of the second belt conveyor 9, the workpiece support belt 19 is worn at the same portion. Accordingly, it is possible to prevent the object to be heat-treated support belt 19 from being worn by rubbing the object to be heat-treated support 19 with the object to be heat-treated.

  Further, when the fluid pressure cylinder 21 of the belt separating mechanism unit 20 is operated, the workpiece support belt 19 is separated from the terminal end of the second belt conveyor 9 as shown in FIG. Since a space portion is formed between the end portion of the second belt conveyor 9 and the heat treatment object support belt 19, whether or not the heat treatment object remains between the end portion of the second belt conveyor 9 and the heat treatment object support belt 19. Can be easily visually recognized.

  Further, since the roller support member 22 of the belt separating mechanism 20 is urged clockwise in the drawing by the tension spring 24, the heat-treated material is transferred to the third belt conveyor 10 even when the amount of the heat-treated material is small. It is possible to suppress falling before moving to the vicinity of the upper surface, and by keeping the length of the buffer belt 19 slack, it is possible to support the object to be heat treated in a wider area, Falling can be further suppressed.

  In the embodiment described above, when pressurized air is supplied from an air supply pipe (not shown) to the air ejection nozzle 12, an air curtain is formed at the entrance of the quenching heating furnace 2 by the air ejected from the air ejection nozzle 12. The air curtain formed at the entrance of the quenching heating furnace 2 makes it difficult for the atmospheric gas to leak from the entrance of the quenching heating furnace 2. Thereby, since it is not necessary to always supply a large amount of atmospheric gas into the heating furnace 2 for quenching, the supply amount of the atmospheric gas supplied into the heating furnace 2 for quenching can be reduced. In addition, leakage of the atmospheric gas can be suppressed without reducing the light brightness of the heat-treated object to be heat-treated. In this case, the jet pressure of the air jetted from the air jet nozzle 12 is such that the atmospheric gas in the quenching heating furnace 2 does not flow out of the entrance portion of the quenching heating furnace 2 and the air jet nozzle 12 It is preferable to set the jet pressure so that the jetted air does not flow into the quenching heating furnace 2.

  Furthermore, when a flame curtain is formed at the entrance of the quenching heating furnace 2 by the flame curtain forming burner 14, the atmosphere gas is heated for quenching by the flame curtain formed at the entrance of the quenching heating furnace 2. Since it burns in the entrance part of the furnace 2, it can prevent that the atmospheric gas in the heating furnace 2 for hardening is discharge | released outside. Preferably, the air curtain and the flame curtain are prevented from interfering with each other by adjusting the installation positions of the air ejection nozzle 12 and the flame curtain forming burner 14 so that the air curtain and the flame curtain do not cross each other. An effect can be obtained. Further, in order to make it difficult to entrain air around the air curtain and to form a stable air curtain, it is preferable to provide a cover member 13 around the air ejection nozzle 12 and to form the air curtain stably. For this purpose, it is preferable to provide the air jet nozzle 12 above the furnace inlet and jet air downward. Further, since the combustion gas in the flame curtain is light at high temperature, the flame curtain forming burner 14 is preferably installed below the furnace inlet, preferably just below the mesh belt 7b (between the carry-in mesh belt and the return mesh belt). .

Further, in the first embodiment described above, the cover plate 26 made of metal is provided on the inner surface portion of the tempering heating furnace 3 made of the heat insulating material 25, and the inner surface portion of the tempering heating furnace 3 is made by the cover plate 26. By covering without gaps, the cleaning liquid component and oil do not adhere to the heat insulating material 25 of the tempering heating furnace 3, so that deterioration of the heat insulating material 25 can be suppressed. Further, it is possible to easily remove the cleaning liquid component and oil adhering to the inner and outer surface portions of the tempering heating furnace 3. In addition, since a gas burner is used instead of electricity, the atmosphere in the furnace containing the cleaning liquid component and oil can be always discharged.
In the first embodiment described above, the case where the present invention is applied to a continuous heat treatment apparatus is illustrated, but the present invention is not limited to this, and the present invention can also be applied to a batch heat treatment apparatus.

It is a figure which shows schematic structure of the heat processing apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the 1st principal part of the heat processing apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the 2nd principal part of the heat processing apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the 3rd principal part of the heat processing apparatus which concerns on the 1st Embodiment of this invention. It is a top view which shows the exit part of the heating furnace for tempering in the heat processing apparatus which concerns on the 1st Embodiment of this invention. It is a side view of the roller chain conveyor shown in FIG. It is sectional drawing which follows the VII-VII line of FIG. It is a figure for demonstrating the effect | action of the to-be-heated material delivery mechanism shown in FIG.

Explanation of symbols

2 Heating furnace for quenching 3 Heating furnace for tempering 4 Quenching oil tank 5 Washing water shower device 7 First belt conveyor 8 Chute 9 Second belt conveyor 10 Third belt conveyor 11 Fourth belt conveyor (mesh conveyor)
13 Air ejection nozzle 14 Flame burner 16 Material to be heat treated 27 Roller chain conveyor 28 Roller chain 29 Drop prevention plate

Claims (3)

In a heat treatment apparatus provided with a heating furnace and a mesh belt conveyor for conveying an object to be heat treated in the heating furnace,
A roller chain conveyor having roller chains on both sides of the mesh belt conveyor and having a shorter conveying distance than the mesh belt conveyor is provided on the lower surface side of the mesh belt conveyor, and prevents the heat-treated material from dropping from the mesh belt conveyor. The roller chain conveyor is provided with a plurality of fall prevention plates, and the diameter of the transport roller for the mesh belt conveyor disposed on the outlet side of the heating furnace is set to the sprocket for the roller chain conveyor or the roller chain conveyor. The heat processing apparatus characterized by making it smaller than the diameter of the conveyance roller. A quenching heating furnace, a tempering heating furnace provided at a subsequent stage of the quenching heating furnace, a quenching oil tank provided between the tempering heating furnace and the quenching heating furnace, A cleaning device provided between the quenching oil tank and the tempering heating furnace, a first belt conveyor for transporting the heat-treated material into the quenching heating furnace, and the quenching by the first belt conveyor. A chute for feeding the material to be heat-treated transported into the heating furnace into the quenching oil tank, a second belt conveyor for pulling up the material to be heat-treated into the quenching oil tank from the chute, In a heat treatment apparatus comprising a third belt conveyor that conveys the object to be heat-treated pulled up from the quenching oil tank by the belt conveyor of 2 to the cleaning device,
A heat-treated material delivery mechanism for delivering a heat-treated material pulled up from the quenching oil tank to the third belt conveyor in the vicinity of the upper surface of the belt conveyor is provided in the vicinity of an end portion of the second belt conveyor, and the heat treatment The object delivery mechanism has a slack between the lower roller provided near the upper surface of the third belt conveyor, the upper roller provided above the lower roller, and the upper roller and the lower roller. A heat treatment apparatus comprising a heat treatment object support belt that is stretched over in a heated state. A heat treatment method, wherein a heat treatment is performed on an object to be heat treated using the heat treatment apparatus according to claim 1.

Images