JP2020016372A - Continuous type atmosphere heat treatment furnace - Google Patents

Abstract

To provide a continuous type atmosphere heat treatment furnace capable of heating the object to be heated from an ordinary temperature to a prescribed temperature in a short time while suppressing the generation of oxide scales and soot.SOLUTION: A continuous type atmosphere heat treatment furnace 10 comprises: carrying means of carrying a wire rod coil W; a rapid cooling pre-heat chamber 16 of performing the rapid pre-heating of the wire rod coil W in an oxidizing atmosphere; an inlet side purge chamber 18 adjacent to the rapid pre-heat chamber 16 and performing vacuum purge in the chamber; a rapid heating chamber 20 adjacent to the inlet side purge chamber 18 and performing rapid heating to the wire rod coil W in a reducing atmosphere; a heat treatment chamber 22 adjacent to the rapid heating chamber 20 and performing heat treatment to the wire rod coil W in a reducing atmosphere; and an outlet side purge chamber 24 adjacent to the heat treatment chamber 22 and performing vacuum purge in the chamber.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a continuous atmosphere heat treatment furnace for continuously heat-treating an object to be heated such as a wire coil in an atmosphere gas.

  Patent Literature 1 listed below discloses an invention regarding a heat treatment apparatus for performing heat treatment of a wire coil, in which a closing plate (lid) for closing an upper end of the wire coil is provided, from below the inner diameter hole of the wire coil. It is disclosed that the heating gas blown upward is circulated outward from the inner diameter side to the outer diameter side of the wire coil to heat the wire coil uniformly in a short time.

However, even when such a heat treatment apparatus is used, when heating in an oxidizing atmosphere, there is a problem that oxide scale is generated on the surface of the wire coil in a high-temperature region, and decarburization occurs in the parent phase. Further, when heating in a reducing atmosphere, there is a problem that CO in the gas composition is decomposed into C and CO ₂ at a low temperature, and soot generated adheres to the surface of the wire coil.

  As a method of solving such a quality problem, it is conceivable to change the atmosphere properties of the heat treatment apparatus by replacing the gas in the furnace according to the heating temperature range. A new problem such as extension of the heat treatment time corresponding to the time required for changing the atmosphere occurs.

Japanese Patent No. 2913727

  The present invention provides a continuous atmosphere heat treatment furnace capable of heating an object to be heated from a normal temperature to a predetermined temperature in a short time while suppressing the generation of oxide scale and soot in the background as described above. It was made for the purpose of.

  Thus, the present invention is a continuous atmosphere heat treatment furnace for heat-treating an object to be heated, a conveying means for conveying the object to be heated, and a first heating chamber for rapidly preheating the object to be heated in an oxidizing atmosphere. An inlet-side purge chamber adjacent to the first heating chamber and performing vacuum purging of the chamber; and a second heating chamber adjacent to the inlet-side purge chamber and rapidly heating the object to be heated in a reducing atmosphere. A heat treatment chamber adjacent to the second heating chamber and performing heat treatment of the object to be heated in a reducing atmosphere; and an outlet-side purge chamber adjacent to the heat treatment chamber and performing vacuum purging of the chamber. It is characterized by being.

As described above, the continuous atmosphere heat treatment furnace of the present invention has a first heating chamber in an oxidizing atmosphere suitable for heating in a low temperature region (where oxidation scale is not easily generated) and a high temperature region (in which soot is not easily generated). And a second heating chamber having a reducing atmosphere suitable for heating. In the present invention, an object to be processed is moved from the first heating chamber to the second heating chamber by using the transfer means at an intermediate stage from the room temperature to the target temperature, so that the oxidation scale in the oxidizing atmosphere is reduced. Both generation and generation of soot in a reducing atmosphere can be satisfactorily suppressed.
Further, in the present invention, it is not necessary to exchange the gas in the furnace (in the room) according to the heating temperature range, and the temperature of the object to be heated can be raised to the target temperature in a short time.

  In the present invention, when the object to be heated is a wire coil, the first heating chamber is provided with a first lid disposed near an upper end of the wire coil, and a first heating unit for heating gas in the chamber. A first gas blower that blows the gas into the inner diameter hole of the wire coil from below.

  Similarly, also for the second heating chamber, a second lid disposed near the upper end of the wire coil, a second heating means for heating gas in the room, and the gas to the inner diameter hole of the wire coil A second gas circulation device that blows in from below.

  With this configuration, the gas blown into the inner diameter hole of the wire coil is prevented from flowing out from the upper end of the inner diameter hole by the lid. For this reason, the gas flows from the inner diameter side to the outer diameter side through the gap between the wires constituting the wire coil. With such a gas flow, the wire coil can be heated to a predetermined temperature in a short time while keeping the temperature difference between the inside, outside, and the top and bottom of the wire coil at a minimum.

In the present invention, the atmosphere in the first heating chamber may be heated to 300 to 550 ° C.
In the present invention, since the object to be heated is rapidly preheated in the first heating chamber under an oxidizing atmosphere, it is necessary to pay attention to the generation of oxide scale in the first heating chamber. The temperature at which oxide scale is generated varies depending on the type of steel, but is about 300 to 550 ° C. For this reason, the first heating chamber is heated to 300 to 550 ° C. as the indoor atmosphere, and it is desirable to set the preheating temperature within this range according to the type of steel. For example, in the case of carbon steel, the temperature is desirably set to 500 to 550 ° C.

  In the present invention, a rapid cooling chamber adjacent to the outlet-side purge chamber may be further provided. In this manner, the time required for heating the object to be heated can be reduced, and the time required for cooling can be further reduced.

It is a figure showing the continuous type atmosphere heat treatment furnace of one embodiment of the present invention. It is the figure which expanded and showed the rapid preheating chamber of FIG. 1, the inlet side purge chamber, and the rapid heating chamber with its peripheral part. It is sectional drawing of the rapid preheating chamber of FIG. It is sectional drawing of the rapid heating chamber of FIG. FIG. 2 is an enlarged view showing an outlet side purge chamber and a rapid cooling chamber of FIG. 1 together with peripheral portions thereof. It is sectional drawing of the rapid cooling chamber of FIG.

Next, a continuous atmosphere heat treatment furnace according to an embodiment of the present invention will be described in detail with reference to the drawings.
In FIG. 1, W is a wire coil as a material to be heated in which the wire is wound in a coil shape, and 10 is a continuous atmosphere heat treatment furnace for annealing the wire coil W.
The continuous atmosphere heat treatment furnace 10 includes a rapid preheating chamber 16 as a first heating chamber, an inlet-side purge chamber 18, and a second heating chamber between a charging table 12 at the left end in the drawing and a discharge table 14 at the right end in the drawing. A rapid heating chamber 20, a heat treatment chamber 22, an outlet side purge chamber 24, and a rapid cooling chamber 26 as chambers are arranged.

  Rollers 31, 32, 33, 34, 35, and 36 are provided in each of the chambers constituting the continuous atmosphere heat treatment furnace 10 as transport means that are independently driven, and the wire coil W is placed in a tray 38 (see FIG. 2). 3) While the sheet is placed on the upper side, the rollers are sequentially conveyed rightward in the drawing by the roller groups 31 to 36, and the annealing process is continuously performed.

  The heat treatment chamber 22 extended in the transport direction performs heat treatment (annealing) of the wire coil W in a reducing atmosphere. In the heat treatment chamber 22, an opening 22 a on the front side (upstream side in the transport direction) can be closed by a partition door 44. The partition door 44 is suspended by a pulley 46a via a wire, and moves up and down by rotation of the pulley 46a. When the partition door 44 is closed, the heat treatment chamber 22 is partitioned from the adjacent rapid heating chamber 20.

  An opening 22 b on the rear side (downstream side in the transport direction) of the heat treatment chamber 22 can be closed by a heat insulating door 45. The heat insulating door 45 is suspended by a pulley 46b via a wire, and moves up and down by the rotation of the pulley 46b.

43, RX gas into the heat treatment chamber _{22 (N 2: 45.1%,} CO: 19.6%, CO 2: 0.4%, H 2: 34.6%, CH 4: 0.3%) , etc. The reducing gas is supplied into the heat treatment chamber 22 at a substantially central position in the longitudinal direction by a gas supply pipe for supplying the reducing gas. The supplied reducing gas flows toward the left in the drawing (that is, the front side of the heat treatment chamber 22) and the gas flowing toward the right (that is, the rear side of the heat treatment chamber 22) in the drawing based on the pressure difference in the heat treatment chamber 22. Create a flow.

  A plurality of radiant tube burners 40 and ceiling fans 42 as heating means are provided in the heat treatment chamber 22 along the transport direction. The inside of the heat treatment chamber 22 is divided into zones for temperature rise, soaking, and slow cooling along the transport direction, and the output of the radiant tube burner 40 is controlled so that a predetermined temperature is set in each zone.

  FIG. 2 is an enlarged view of the rapid preheating chamber 16, the inlet side purge chamber 18, and the rapid heating chamber 20 provided upstream of the heat treatment chamber 22.

The rapid preheating chamber 16 adjacent to the charging table 12 is for rapidly preheating the wire coil W at approximately room temperature to a predetermined preheating temperature while suppressing generation of oxidized scale and soot under an oxidizing atmosphere. .
The rapid preheating chamber 16 is provided with heat insulating doors 51a and 51b that can close the front and rear openings 50a and 50b, respectively. These heat insulating doors 51a and 51b are suspended by pulleys 52a and 52b via wires, respectively, and are moved up and down by rotation of the pulleys 52a and 52b.

FIG. 3 is a cross-sectional view of the rapid preheating chamber 16 in a direction orthogonal to the transport direction of the wire coil W, and shows a state where the wire coil W is loaded in the room.
In the same drawing, reference numeral 54 denotes a first lid portion arranged near the upper end of the wire coil W, 57 denotes a direct fire burner as first heating means for heating gas in the preheating chamber, and 58 denotes a first gas blown into the wire coil W. One gas blower. Reference numeral 59 denotes a gas discharge pipe formed at the upper part of the side wall. In the rapid preheating chamber 16, the atmosphere as the oxidizing gas is heated by the burner 57.

  The first lid 54 is attached to the tip of a shaft 55 that vertically penetrates the upper wall of the rapid preheating chamber 16, and is covered by the wire coil W so as to close the upper end of the wire coil W. The first lid portion 54 is connected to an elevating device 56 (see FIG. 2) via a shaft 55, and can be moved up and down. For this reason, in the present example, the gap s between the upper end of the wire coil W and the first lid 54 can be appropriately adjusted.

  The first gas blower 58 includes a duct 60, a blower fan 62 housed inside the duct 60, and a drive motor 63 for driving the blower fan 62 to rotate. As shown in the figure, the duct 60 has a bent shape, and has a gas outlet 60a that opens upward immediately below the wire coil W at one end thereof. On the other hand, a downward gas inlet 60 b is formed at the other end of the duct 60. The blower fan 62 is disposed immediately above the gas suction port 60b.

  In the first gas blower 58, the gas sucked into the duct 60 through the gas inlet 60 b is blown upward from the gas outlet 60 a of the duct 60 by rotating the blower fan 62. Here, a through hole 38a penetrating in the plate thickness direction is formed in the center of the tray 38 located immediately above the gas outlet 60a, and the upward gas passes through the wire coil W after passing through the through hole 38a. It is sent to the inner diameter hole Wa.

  At this time, since the first lid portion 54 is arranged near the upper end of the wire coil W so as to cover the wire coil W, the gas blown into the inner diameter hole Wa of the wire coil W is reduced to the inner diameter Wa. Outflow from the upper end portion is prevented, and flows from the inner diameter side to the outer diameter side as shown by the arrow through the gap between the wires constituting the wire coil W. By realizing such a gas flow, the wire coil W is heated to a predetermined preheating temperature in a short time while keeping the temperature difference between the inside and outside and the top and bottom of the wire coil W at a minimum.

  A temperature sensor 64 detects the temperature of the gas flowing through the duct 60. In this example, the control unit (not shown) connected to the temperature sensor 64 appropriately controls the combustion of the burner 57 so that the temperature of the gas detected by the temperature sensor 64 matches the preset target ambient temperature. Adjusted.

The next inlet-side purge chamber 18 is for preventing atmospheric air from entering a rapid heating chamber 20 of a reducing atmosphere described later. As shown in FIG. 2, the inlet side purge chamber 18 is provided with airtight doors 67a and 67b that can close the front and rear openings 66a and 66b. The airtight doors 67a and 67b are suspended by pulleys 68a and 68b via wires, respectively, and are moved up and down by rotation of the pulleys 68a and 68b.
A pipe 70 for deaeration connected to a vacuum pump 71 and a pipe 73 for supplying N ₂ gas connected to an N ₂ supply device (not shown) are connected to the inlet side purge chamber 18.

The next rapid heating chamber 20 controls the wire coil W preheated to a predetermined temperature in the rapid preheating chamber 16 to a predetermined target temperature while suppressing the generation of oxidized scale and soot in a reducing atmosphere. For rapid heating.
As shown in FIG. 2, the rapid heating chamber 20 is provided with a heat insulating door 75 a capable of closing a front opening 74 a facing the inlet-side purge chamber 18. The heat-insulating door 75a is suspended by a pulley 76a via a wire, and moves up and down by rotation of the pulley 76a.
A compartment 77 is formed between the inlet-side purge chamber 18 and the rapid heating chamber 20 so as to be airtightly shut off from the outside. When the front opening 74a is opened, outside air is prevented from entering the room. The pulley 68b and the airtight door 67b, the pulley 76a and the heat insulating door 75a are housed in the compartment 77.
On the other hand, the opening 74b on the rear side of the rapid heating chamber 20 can be closed by the partition door 44 described above.

  As shown in FIG. 2, the rapid heating chamber 20 is connected to the heat treatment chamber 22 by a supply pipe 79, and by opening an on-off valve provided on the supply pipe 79, the reducing gas in the heat treatment chamber 22 is rapidly heated. It can be supplied into the chamber 20.

FIG. 4 is a cross-sectional view of the rapid heating chamber 20 in a direction orthogonal to the transport direction of the wire coil W, and shows a state where the wire coil W is inserted in the room.
In the same drawing, reference numeral 84 denotes a second lid portion arranged near the upper end of the wire coil W, 87 denotes a radiant tube burner as a second heating means for heating gas in the heating chamber, and 88 denotes a gas blown into the wire coil W. It is a two-gas circulation device.

  The second lid portion 84 is attached to the tip of a shaft 85 that penetrates the upper wall of the rapid heating chamber 20 in the vertical direction, and covers the wire coil W so as to close the upper end of the wire coil W. The second lid portion 84 is connected to a pulley 86 (see FIG. 2) via a shaft body 85, and can be moved up and down. For this reason, in this example, the gap s between the upper end of the wire coil W and the second lid 84 can be appropriately adjusted.

  The second gas circulation device 88 includes a duct 90, a circulation fan 92 housed inside the duct 90, and a drive motor 93 for driving the circulation fan 92 to rotate. The duct 90 has a bent shape as shown in the figure, and has a gas outlet 90a which is open upward just below the wire coil W at one end thereof. On the other hand, a downward gas inlet 90b is formed at the other end of the duct 90. The circulation fan 92 is disposed immediately above the gas suction port 90b.

  As described above, the configurations of the second lid portion 84 and the second gas circulating device 88 are basically the same as those of the first lid portion 54 and the first gas blower 58 described above, and the configuration of the rapid heating chamber 20 of the present example is used. For example, the reducing gas heated by the radiant tube burner 87 flows from the inner diameter side to the outer diameter side as shown by the arrow through the gap between the wires constituting the wire coil W, and the inside and outside of the wire coil W The wire coil W is heated to the predetermined heating temperature in a short time while keeping the temperature difference between the upper and lower sides to a minimum.

  A temperature sensor 94 detects the temperature of the gas flowing through the duct 90. In this example, the control unit (not shown) connected to the temperature sensor 94 controls the combustion of the radiant tube burner 87 so that the temperature of the gas detected by the temperature sensor 94 matches the preset target ambient temperature. Is appropriately adjusted.

FIG. 5 is an enlarged view of the outlet purge chamber 24 and the rapid cooling chamber 26 provided on the downstream side of the heat treatment chamber 22.
The outlet side purge chamber 24 is for preventing air from entering the heat treatment chamber 22 in a reducing atmosphere. The outlet side purge chamber 24 is provided with airtight doors 97a and 97b which can close the front and rear openings 96a and 96b as shown in FIG. The hermetic doors 97a and 97b are suspended by pulleys 98a and 98b via wires, respectively, and move up and down by rotation of the pulleys 98a and 98b.
The outlet side purge chamber 24 is connected to a deaeration pipe 100 connected to a vacuum pump 99 and a N ₂ gas supply pipe 101 connected to an N ₂ supply device (not shown).

  A compartment 102 is formed between the heat treatment chamber 22 and the outlet-side purge chamber 24 so as to be airtightly shut off from the outside, and has a rear opening 22 b of the heat treatment chamber 22 and a front opening of the outlet-side purge chamber 24. When 96a is opened, outside air is prevented from entering the room.

  The next quick cooling chamber 26 is for rapidly cooling the wire coil W under the atmosphere. The rapid cooling chamber 26 is provided with opening and closing doors 106a and 106b that can close the front and rear openings 105a and 105b. These doors 106a and 106b are suspended by pulleys 107a and 107b via wires, respectively, and move up and down by rotation of the pulleys 107a and 107b.

  FIG. 6 is a cross-sectional view of the rapid cooling chamber 26 in a direction orthogonal to the transport direction of the wire coil W, and shows a state where the wire coil W is loaded in the room. In the drawing, reference numeral 110 denotes a third lid portion arranged near the upper end of the wire coil W, and 114 denotes a blower device for blowing cool air (atmosphere) into the inner diameter hole Wa of the wire coil W. Reference numeral 115 denotes a gas discharge pipe formed at an upper portion of the side wall.

The configuration of the rapid cooling chamber 26 is basically the same as the rapid preheating chamber 16 and the rapid heating chamber 20 described above. The third lid portion 110 is attached to the tip of a shaft 111 that penetrates the upper wall of the rapid cooling chamber 26 in the vertical direction, and covers the wire coil W so as to close the upper end of the wire coil W.
The gas outlet 114a of the blower device 114 is disposed immediately below the wire coil W.

  In the thus configured rapid cooling chamber 26 of the present embodiment, unheated air is taken in from the gas inlet port 114b as a cooling gas, and is sent into the inner diameter hole Wa of the wire coil W. This cooling gas flows from the inner diameter side to the outer diameter side as shown by the arrow through the gap between the wires constituting the wire coil W, whereby the wire coil W is rapidly cooled. The gas used for cooling is discharged outside the room through a gas discharge pipe 115.

  Next, the operation of each part of the continuous atmosphere heat treatment furnace 10 when the wire coil W is inserted will be described. When the wire coil W is inserted, first, in the rapid preheating chamber 16, while suppressing generation of oxidized scale and soot under an oxidizing atmosphere, the wire coil W is raised to (for example, 500 ° C.) in accordance with the ambient temperature. Preheat quickly.

Thereafter, the heat-insulating door 51b of the rapid preheating chamber 16 and the airtight door 67a of the inlet-side purge chamber 18 are opened to drive the roller groups 31 and 32 to transfer the preheated wire coil W into the inlet-side purge chamber 18. After closing the airtight door 67a, the pressure in the inlet side purge chamber 18 is reduced using the pressure reducing means 70 and 71, and the air in the room is discharged outside the room. After the evacuation of the inlet-side purge chamber 18 is completed, N ₂ gas is supplied into the inlet-side purge chamber 18 through the pipe 73 and the pressure is restored to normal pressure.

  Thereafter, the airtight door 67b on the outlet side of the inlet side purge chamber 18 and the heat insulating door 75a on the inlet side of the rapid heating chamber 20 are opened, and the roller groups 32 and 33 are driven to transfer the wire coil W into the rapid heating chamber 20. Then, the airtight door 67b and the heat insulating door 75a are closed. The inside of the rapid heating chamber 20 is set in a reducing atmosphere by the supply of the reducing gas through the supply pipe 79, and while suppressing the generation of oxidized scale and soot, the wire coil W (for example, 700 (° C).

  Thereafter, the partition door 44 provided between the rapid heating chamber 20 and the heat treatment chamber 22 is opened, the roller groups 33 and 34 are driven, the wire coil W is transferred to the heat treatment chamber 22, and the partition door 44 is closed. Thereafter, the wire coil W is annealed while moving in the heat treatment chamber 22. When the wire coil W reaches the outlet side of the heat treatment chamber 22, the heat insulating door 45 of the heat treatment chamber 22 and the airtight door 97a of the outlet side purge chamber 24 are opened to drive the roller groups 34 and 35, and the wire coil W exits. It is transferred into the side purge chamber 24.

After closing the airtight door 97a, the pressure in the outlet side purge chamber 24 is reduced by the pressure reducing means 99 and 100, and the reducing gas in the room is discharged outside the room. After the evacuation in the outlet-side purge chamber 24 is completed, N ₂ is supplied into the outlet-side purge chamber 24 to return to normal pressure.

  Thereafter, the airtight door 97b on the outlet side of the outlet side purge chamber 24 and the opening / closing door 106a on the inlet side of the rapid cooling chamber 26 are opened, and the roller groups 35 and 36 are driven to transfer the wire coil W into the rapid cooling chamber 26. Then, the airtight door 97b and the open / close door 106a are closed. In the rapid cooling chamber 26, the wire coil W is rapidly cooled using unheated air as a cooling gas. After the cooling, the opening and closing door 106b is opened and the wire coil W is transferred to the carry-out table 14, whereby a series of operations relating to the heat treatment of the wire coil W is completed.

  As described above, the continuous atmosphere heat treatment furnace 10 of the present embodiment includes the rapid preheating chamber 16 of an oxidizing atmosphere suitable for heating in a low temperature region (where oxidation scale is not easily generated) and a high temperature (where soot is not easily generated). And a rapid heating chamber 20 in a reducing atmosphere suitable for heating in the region. In the present embodiment, by moving the wire coil W from the rapid preheating chamber 16 to the rapid heating chamber 20 using a group of rollers at an intermediate stage from the room temperature to the target temperature, the oxidation scale in the oxidizing atmosphere is reduced. Both generation of soot and generation of soot in a reducing atmosphere can be satisfactorily suppressed. Further, in the continuous atmosphere heat treatment furnace 10 of the present embodiment, it is not necessary to exchange the gas inside the furnace (in the room) according to the heating temperature range, and the temperature of the wire coil W can be raised to the target temperature in a short time. Can be.

In the present embodiment, the rapid preheating chamber 16 includes a first lid portion 54 disposed near the upper end of the wire coil W, a direct-fire burner 57 for heating gas in the room, and gas to the inner diameter hole Wa of the wire coil W. A first gas blower 58 that blows in from below.
Similarly, the rapid heating chamber 20 includes a second lid portion 84 disposed near the upper end of the wire coil W, a radiant tube burner 87 for heating gas in the room, and a gas flowing downward to the inner diameter hole Wa of the wire coil W. And a second gas circulating device 88 that blows in from the air.
By configuring the rapid preheating chamber 16 and the rapid heating chamber 20 in this way, it is possible to heat the wire coil W to a predetermined temperature in a short time while keeping the temperature difference between the inside and outside and the top and bottom of the wire coil W at a minimum. Can be.

  Further, in the continuous atmosphere heat treatment furnace 10 of the present embodiment, since the rapid cooling chamber 26 adjacent to the outlet side purge chamber 24 is provided, the time required for cooling the wire coil W can be reduced.

  The embodiments of the present invention have been described above in detail, but these are merely examples. For example, the atmosphere temperature in the rapid preheating chamber 16 and the atmosphere temperature in the rapid heating chamber 20 can be appropriately changed within a range in which the generation of soot and oxide scale can be suppressed. In addition, the present invention can be implemented in variously modified forms without departing from the spirit thereof, for example, the compositions of the oxidizing gas and the reducing gas used for heating can be appropriately changed.

10 Continuous atmosphere heat treatment furnace 16 Rapid preheating chamber (first heating chamber)
18 Inlet side purge chamber 20 Rapid heating chamber (second heating chamber)
Reference Signs List 22 Heat treatment chamber 24 Outlet side purge chamber 26 Rapid cooling chamber 31, 32, 33, 34, 35, 36 Roller group (transporting means)
54 First lid 57 Direct fire burner (first heating means)
58 first gas blower 84 second lid 87 radiant tube burner (second heating means)
88 Second gas circulation device W Wire coil (heated material)
Wa inner diameter hole

Claims (5)

A continuous atmosphere heat treatment furnace for heat treating an object to be heated,
Conveying means for conveying the object to be heated,
A first heating chamber for rapidly preheating the object to be heated in an oxidizing atmosphere;
An inlet-side purge chamber which is adjacent to the first heating chamber and in which vacuum purging of the chamber is performed;
A second heating chamber adjacent to the inlet-side purge chamber and performing rapid heating of the object to be heated in a reducing atmosphere;
A heat treatment chamber adjacent to the second heating chamber, the heat treatment chamber performing heat treatment of the object to be heated in a reducing atmosphere;
A continuous atmosphere heat treatment furnace, comprising: an outlet side purge chamber adjacent to the heat treatment chamber, where the inside of the chamber is subjected to vacuum purging. The heat target is a wire coil,
The first heating chamber has a first lid disposed near an upper end of the wire coil, first heating means for heating gas in the room, and a first blower that blows the gas into an inner diameter hole of the wire coil from below. The continuous atmosphere heat treatment furnace according to claim 1, further comprising a gas blower. The heat target is a wire coil,
The second heating chamber has a second lid disposed near the upper end of the wire coil, a second heating means for heating gas in the room, and a second blower that blows the gas into an inner diameter hole of the wire coil from below. The continuous atmosphere heat treatment furnace according to claim 1, further comprising a gas circulation device.   The continuous atmosphere heat treatment furnace according to any one of claims 1 to 3, wherein the first heating chamber heats the atmosphere in the room to 300 to 550 ° C.   The continuous atmosphere heat treatment furnace according to any one of claims 1 to 4, further comprising a rapid cooling chamber adjacent to the outlet-side purge chamber.

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