JP2003213323A - Conveying roller, conveying tray and heat treatment furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveying roller which prevents the melt-stickiness and the carburization between the conveying roller and a conveying tray can, and the conveying tray which prevents the melt-stickiness and the carburization between the conveying tray and a material to be treated, and a heat treatment furnace provided with the roller and tray. <P>SOLUTION: Contacting parts 42a, 42a on the conveying roller 40 with the conveying tray 43 and contacting part of the conveying tray 43 with the material 44 to be treated, are coated with yttrium oxide (Y<SB>2</SB>O<SB>3</SB>) films 55, 56, respectively. Since the yttrium oxide has excellent wear resistance, heat resistance, chemical and physical stabilities in the high temperature, the melt-stickiness and the carburization between the conveying roller 40 and the conveying tray 43, and the melt-stickiness and the carburization between the conveying tray 43 and the material 44 to be treated, are prevented. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrying roller, a carrying tray, and a heat treatment furnace, and more specifically, to a carrying process used in a continuous heat treatment furnace for heat-treating an object in a vacuum or in an inert gas atmosphere. The present invention relates to rollers and carrier trays.

[0002]

2. Description of the Related Art For example, as a transfer system for an object to be processed in a roller hearth type continuous heat treatment furnace, there is conventionally a system constituted by a plurality of transfer rollers arranged in a hearth. The transport rollers have a shaft shape extending orthogonal to the transport direction of the object to be processed, a plurality of transport rollers are arranged in parallel in the transport direction of the object to be processed, and are rotationally driven in synchronization with each other.

The transport roller is required to have sufficient mechanical strength for transporting the object to be processed and heat resistance to withstand high-temperature processing of the object to be processed, and must be made of a material satisfying such requirements. There is. Therefore, for example, Japanese Unexamined Patent Application Publication 2001
As described in JP-A-289566, there is one in which a shaft member of a conveying roller is made of a solid carbon-based composite material (a material in which carbon fibers are mixed in a carbon matrix).

3 and 4 show a schematic structure of the conventional heat treatment furnace. 3 and 4 respectively show the internal structure of the conventional heat treatment furnace. FIG. 3 is a sectional view as seen from the front in the transport direction, and FIG. 4 is a plan view as seen from directly above the transport rollers.

Inside the double-walled furnace wall 30, a heat insulating casing 31 is provided via a base portion 34 in order to suppress thermal loss in the furnace. Be transported. At the bottom of the heat insulating casing 31,
A pair of guide rails 28, 2 via the support portions 33, 33
8 is attached, and a plurality of conveying rollers 20 are arranged between these guide rails 28, 28 in parallel with their axial directions orthogonal to the conveying direction to form a hearth.

The driving of each of the carrying rollers 20 is performed by a driving source arranged outside the furnace, not shown.
It is rotationally driven in synchronization in the same direction via the drive portion connecting portion 32 formed at one end of the. In addition, an introduction means for introducing an atmosphere gas such as an inert gas, a heater as a heating source, and a vacuum exhaust means for exhausting the inside of the furnace are provided in the furnace, but they are not shown.

The transport roller 20 is mainly composed of a shaft member 21 supported by bearings 26, 26 provided on a pair of guide rails 28, 28. The shaft member 21 is made of a carbon-based composite material (so-called high-strength carbon) in which carbon fibers are mixed in a carbon matrix, and the longitudinal direction of the carbon fibers is arranged in the axial direction of the shaft member 21.

In the conventional heat treatment furnace, since the shaft member constituting the carrying roller is made of a carbon-based composite material, the carrying tray needs to be made of the same kind of carbon-based composite material. Generally, when there is a system having various conveying lines before and after the apparatus, a tray made of metal such as stainless steel, which is advantageous in handling, is desired. This is because there is a problem that the tray is carburized due to contact with the member, which causes alteration and embrittlement of the tray.

Therefore, as shown in FIGS. 3 and 4,
If the transport roller 20 is constituted by the shaft member 21 and the metal ring members 22, 22 that are integrally coupled to the shaft member 21 and contact the lower surface of the transport tray T,
Since direct contact between the shaft member 21 and the transport tray T is avoided, this makes it possible to employ a metal tray.

[0010]

However, even if the transport roller 20 is configured as described above, welding at the contact interface between the metal tray T and the ring members 22 at a high temperature poses a problem. Therefore, in the case of light load processing, the ring member 22 is made of a ceramic material such as aluminum oxide (Al ₂ O ₃ ), or the contact surface of the ring member 22 with the tray T is coated with Al ₂ O _3. However, there is a problem that the ring member is easily scraped and the coating film is peeled off.

Further, welding at the contact portion between the carbon composite tray and the object to be treated and carburization of the object to be treated may pose a problem. Therefore, conventionally, a treatment such as applying boron nitride (BN) coating to the contact surface of the transport tray with the object to be processed has been taken. Further, welding at the contact portion between the metal tray and the object to be processed may be a problem. Therefore, conventionally, the contact surface of the carrier tray with the object to be processed is coated with Al ₂ O ₃ or the like.

However, each of the above coating films has a problem that they are easily peeled off.

The present invention has been made in view of the above problems, and a carrying roller capable of preventing welding and carburization between a carrying roller and a carrying tray, and welding and carburizing between a carrying tray and an object to be treated. An object of the present invention is to provide a transport tray that can be prevented, and a heat treatment furnace including the transport tray.

[0014]

In order to solve the above problems, the carrying roller of the present invention is a carrying roller for carrying a carrying tray containing an object to be processed in a heat treatment chamber, and is a carbon-based composite roller. It is characterized by comprising a shaft member made of a material, and a surface area in contact with the carrying tray is covered with a yttrium oxide film.

Further, another carrying roller of the present invention is a carrying roller for carrying a carrying tray containing an object to be processed in the heat treatment chamber, and extends in a direction orthogonal to the carrying direction of the carrying tray. In a transport roller having a shaft member and a ring member that supports the lower surface of the transport tray and is integral with the shaft member, the shaft member is made of a carbon-based composite material, and the ring member is made of a metal material, An yttrium oxide film is formed on the contact surface of the ring member with the transport tray.

The carrying roller according to the present invention has an yttrium oxide film formed on the contact surface of the carrying roller with the carrying tray. Yttrium oxide (Y ₂ O ₃ ) has a melting point of 2410.
It is a colorless cubic crystal that is thermally stable at ℃, and has excellent wear resistance, heat resistance, and chemical and physical stability at high temperatures. Carburization from the transfer tray to the transfer tray is prevented.

Further, the carrying tray of the present invention is carried on a plurality of carrying rollers arranged on the hearth of the heat treatment furnace, and comes into contact with the object to be processed in the carrying tray for containing the object to be processed. The yttrium oxide film is formed on the upper surface of the tray. This prevents welding of the transport tray and the object to be processed and carburization of the object to be processed.

Further, the heat treatment furnace of the present invention is a heat treatment furnace for subjecting the object to be treated to a predetermined heat treatment while conveying a carrier tray containing the object to be treated by a plurality of conveying rollers. In a heat treatment furnace in which a transport roller has a shaft member extending in a direction orthogonal to the transport direction of the transport tray, and a ring member that supports the lower surface of the transport tray and is integral with the shaft member, the shaft member is The ring member is made of a carbon-based composite material, and the ring member is made of a metal material, and an yttrium oxide film is formed on a contact surface of the ring member with the transport tray.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In each of the following embodiments, an example in which the present invention is applied to a roller hearth type heat treatment furnace for performing a predetermined heat treatment (quenching, tempering, annealing, sintering, etc.) on a workpiece is described. To do.

FIG. 1 shows, as a first embodiment of the present invention, a structure of a carrying roller arranged in a hearth of a heat treatment furnace for a medium temperature range (for example, around 600 ° C.). It is suitable for transportation.

The carrying rollers 40 are a pair of shaft members 41 extending in a direction orthogonal to the carrying direction of the object to be processed, and a pair of integrally provided around the shaft members 41 for supporting both lower edges of the carrying tray 43. And ring members 42, 42 of.

The shaft member 41 is a solid carbon composite material of high strength and high heat resistance in which carbon fibers are mixed in a carbon matrix so that the longitudinal direction thereof is aligned with the axial direction of the shaft member 41.
Alternatively, it is made of carbon steel. When the shaft member 41 is made of a carbon steel material, a cooling water circulation passage may be formed in a solid shape or inside.

The ring members 42, 42 are made of a metallic material, and the material is selected according to the applied processing temperature. For example, general carbon steel is used in the temperature atmosphere of 500 ° C. to 650 ° C., stainless heat-resistant steel is used at a temperature of about 1300 ° C., and refractory metal materials such as Mo are used at a temperature higher than that. Is selected.

A plurality of conveying rollers 40 are arranged in the direction perpendicular to the paper surface in FIG. 1, and are driven to rotate synchronously in the same direction, so that the conveying tray 43 accommodating or placing the object 44 to be processed is conveyed. It is configured.

The carrying tray 43 is made of a metal material (for example, stainless steel). The transfer tray 43 is transferred in a processing chamber 46 defined by a heat insulating plate 45 in the furnace.
A heating means 4 for heating the processing chamber 46 to a predetermined temperature, such as an electric heater, is provided at a predetermined portion of the processing chamber 46.
7 are arranged.

The conveying roller 40 penetrates the heat insulating plates 45, 45, and each end portion thereof is provided with a supporting member 49 attached to an airtight chamber 48 having a water cooling jacket structure forming a furnace wall.
49 are rotatably supported by bearings 50 and 50, respectively. Heat insulating plates 45, 4 through which the transport roller 40 penetrates
The through holes 45a and 45a of No. 5 are covered with heat insulating shield plates 52 and 53 that are integral with the transport roller 40 on the processing chamber 46 side, and the bearings 50 and 50 are directly exposed to the heat of the processing chamber 46. I try not to be.

A sprocket 54 that meshes with the driving force transmission chain 51 is attached to one end (right side in FIG. 1) of the conveying roller 40. In addition, an introducing means for introducing an atmospheric gas such as an inert gas into the processing chamber 46 and a vacuum exhausting means for exhausting the inside of the processing chamber 46 are provided, but the illustration thereof is omitted. .

Now, in the present embodiment, the transport tray 4 of the ring members 42, 42 constituting the transport roller 40.
A film 55 made of a yttrium oxide (Y ₂ O ₃ , yttria) film is formed on the contact surface with ₃ .

The ring members 42, 42 are cylindrical guide portions 42a, 42a for supporting the lower surface of the carrying tray 43, respectively.
42a and the transport tray 4 from the guide portions 42a, 42a
Frustum-shaped restricting portion 42b for preventing separation of
42b, of which, in the present embodiment, the coating film 5 having the above-mentioned configuration is formed on the peripheral surfaces of the guide portions 42a, 42a.
5 is formed. Of course, not limited to this, the coating 55 may be formed on the entire peripheral surfaces of the ring members 42, 42.

A film 56 of yttrium oxide (Y ₂ O ₃ , yttria) film is also formed on the upper surface of the transfer tray 43, which is the contact surface between the transfer tray 43 and the object 44 to be processed. The transport tray 43 may be in the form of a shallow dish, a lattice, or the like.

In this embodiment, the coatings 55 and 56 are formed by thermal spray coatings having a thickness of about 100 μm.
That is, the coatings 55 and 56 are formed by a thermal spraying method (for example, plasma spraying method). In addition to the thermal spraying method, other coating forming methods such as a coating method and a dipping method may be used.

Next, the operation of the present embodiment configured as described above will be described.

In the heat treatment furnace according to the present invention, the inside of the furnace is kept in a vacuum atmosphere or an inert gas atmosphere under normal pressure or reduced pressure, and a predetermined heat treatment is performed on a metal material or a heat treatment (sintering) is performed on a compression molding of powder metal. ) And so on. Such an object to be processed is carried by the carrying roller 40 in a form of being housed or placed on the carrying tray 43, and a predetermined heat treatment is performed during the carrying.

The carrying tray 43 is carried on the carrying roller 40 which is synchronously driven in a predetermined direction by the driving force transmitting chain 51. At this time, the transport tray 43 is supported by the guide portions 42a, 42a of the pair of ring members 42, 42 of the transport roller 40. Ring members 42, 4
2 avoids direct contact between the shaft member 41 made of a carbon-based composite material and the metal transport tray 43, and prevents carburization of the transport tray 43.

On the other hand, the guide portion 4 of the ring members 42, 42
At the contact portion between the 2a, 42a and the transfer tray 43, the weight load of the object to be processed 43 acts at high temperature (for example, 1700 ° C.). In the present embodiment, the ring member 42,
A spray coating 55 of yttrium oxide is provided on the peripheral surfaces of the guide portions 42a, 42a of 42. Since the yttrium oxide coating has a high melting point of 2410 ° C. and is excellent in wear resistance, heat resistance, and chemical and physical stability at high temperatures, according to the present embodiment, the guide portions 42a and 42a and the conveyance portions 42a and 42a are conveyed. Welding with the tray 43 is prevented. Further, since the film 55 is not easily scraped or peeled off, the durability of the transport roller 40 can be improved.

Further, according to the present embodiment, since the yttrium oxide film 56 is also formed on the contact surface of the transfer tray 43 with the object 44 to be processed, the yttrium oxide film 56 is formed between the transfer tray 43 and the object 44 to be processed. Welding is prevented.

Next, a second embodiment of the present invention will be described. FIG. 2 shows a second embodiment of the present invention.
The structure of the conveyance roller arrange | positioned at the hearth of the heat processing furnace for high temperature regions (for example, about 1700 degreeC) is shown. The heat treatment furnace of the present embodiment is suitable for carrying a carrying tray made of a carbon-based composite material.

The carrying rollers 60 are a pair of shaft members 61 extending in a direction orthogonal to the carrying direction of the object to be processed, and a pair of members integrally provided around the shaft members 61 for supporting both lower edges of the carrying tray 63. And ring members 62, 62 of.

The shaft member 61 is made of a high-strength, high-heat-resistant solid carbon-based composite material in which carbon fibers are mixed in a carbon matrix, or carbon steel. Shaft member 6
When 1 is made of a carbon steel material, a cooling water circulation passage may be formed in a solid state or inside.

The ring members 62, 62 are made of a metallic material, and a high melting point metal such as general structural carbon steel, stainless steel heat resistant steel, Mo is selected according to the processing temperature.

A plurality of conveying rollers 60 are arranged in the direction perpendicular to the paper surface of FIG. 2, and are driven to rotate synchronously in the same direction so that the conveying tray 63 accommodating or placing the object 64 to be conveyed is conveyed. It is configured.

The carrying tray 63 is made of a high-strength, high-heat-resistant carbon-based composite material in which carbon fibers are mixed in a carbon matrix so that its longitudinal direction is aligned in the axial direction of the shaft member 61. The transfer tray 63 is transferred in a processing chamber 66 defined by a heat insulating plate 65 in the furnace. At a predetermined portion of the processing chamber 66, a heating means 67 for heating the processing chamber 66 to a predetermined temperature, such as an electric heater, is arranged.

The conveying roller 60 penetrates the heat insulating plates 65, 65, and each end thereof is provided with a supporting member 69 attached to an airtight chamber 68 having a water cooling jacket structure forming a furnace wall.
69 are rotatably supported by bearings 70 and 70, respectively. Heat insulating plates 65, 6 through which the transport roller 60 penetrates
Insulating support members 77, 77 integral with the transport roller 40 are rotatably supported in the through holes 65a, 65a of No. 5, respectively.

It should be noted that the hole 68a of the chamber 68, through which the transport roller 60 penetrates, is provided on the processing chamber 46 side.
The bearings 70 and 70 are respectively covered with heat insulating shield plates 72 and 73 which are integral with 0, so that the bearings 70 and 70 are not directly exposed to the heat of the processing chamber 66. A sprocket 74 that meshes with the driving force transmitting chain 71 is attached to one end (left side in FIG. 2) of the transport roller 60.

In addition to the above, an introducing means for introducing an atmospheric gas such as an inert gas into the processing chamber 46 and the processing chamber 46.
Evacuation means for exhausting the inside is installed,
The illustration is omitted.

In the present embodiment as well, as in the above-described first embodiment, a spray coating 76 of yttrium oxide (Y ₂ O ₃ , yttria) having a thickness of about 100 μm is formed on the upper surface of the carrying tray 63. Has been formed. Transport tray 63
Any of a shallow dish shape, a lattice shape, etc. can be applied.

According to the present embodiment configured as described above, since the spray coating 76 of yttrium oxide is formed on the contact surface of the transfer tray 63 with the workpiece 64, it is made of a carbon-based composite material. Direct contact with the transport tray 63 is avoided, and as a result, carburization of the workpiece 64 can be prevented.

Although the respective embodiments of the present invention have been described above, of course, the present invention is not limited to these.
Various modifications are possible based on the technical idea of the present invention.

For example, in the above-described first embodiment, in order to prevent carburization due to contact between the shaft member 41 made of a carbon-based composite material and the metal carrying tray 43, the carrying tray 4 is used.
Although the ring member 42 that supports 3 is provided integrally with the shaft member 41 to configure the transport roller 40, the ring member 42 may be omitted. In this case, by covering the surface region of the shaft member 41 that contacts the transport tray 43 with the yttrium oxide film, it is possible to prevent carburization of the transport tray 43 and wear the shaft member due to sliding contact with the transport tray 43. Is also suppressed.

[0050]

As described above, according to the present invention, since the yttrium oxide film is formed in the contact portion with the metallic transport tray, welding with the transport tray and carburization of the transport tray are prevented. be able to.

Further, since the yttrium oxide film is formed on the upper surface of the tray which is in contact with the object to be processed of the carrying tray made of carbon-based composite material, welding with the object to be processed and carburization of the object to be processed are prevented. be able to.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a structure of a conveyance roller of a heat treatment furnace according to a first embodiment of the present invention.

FIG. 2 is a side sectional view showing a structure of a conveyance roller of a heat treatment furnace according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a conventional heat treatment furnace.

FIG. 4 is a plan view of an essential part in FIG.

[Explanation of symbols]

40 transport rollers 41 Shaft member 42 Ring member 43 Transport tray 44 Object to be processed 46 Processing room 55 Thermal spray coating 56 Thermal spray coating 60 transport rollers 61 Shaft member 62 ring member 63 Transport tray 64 Object to be processed 66 Processing room 76 Thermal spray coating

Continued front page    F-term (reference) 3F033 GA06 GB06 GC01 GD07 GE01                 4K018 AD01 JA16 KA07 KA17 KA22                 4K034 AA17 AA19 EA12 EB03 EB08

Claims (7)

[Claims] 1. A transport roller for transporting a transport tray containing an object to be processed in a heat treatment chamber, comprising a shaft member made of a carbon-based composite material, and a surface area in contact with the transport tray is oxidized. A conveyance roller characterized by being coated with an yttrium film. 2. A transport roller for transporting a transport tray containing an object to be processed in a heat treatment chamber, the shaft member extending in a direction orthogonal to a transport direction of the transport tray,
A transport roller that supports a lower surface of the transport tray and has a ring member that is integral with the shaft member, wherein the shaft member is made of a carbon-based composite material, and the ring member is made of a metal material. A transport roller having a yttrium oxide film formed on the contact surface with the transport tray. 3. A transport tray for transporting a plurality of transport rollers arranged on the hearth of a heat treatment furnace to accommodate an object to be treated, wherein a yttrium oxide film is formed on an upper surface of the tray which is in contact with the object to be treated. A transport tray characterized by being formed with. 4. A heat treatment furnace for performing a predetermined heat treatment on the object to be processed while conveying the object containing the object to be processed by a plurality of conveying rollers. In a heat treatment furnace having a shaft member extending in a direction orthogonal to the transport direction, and a ring member that supports the lower surface of the transport tray and is integral with the shaft member, wherein the shaft member is made of a carbon-based composite material. A heat treatment furnace, wherein the ring member is made of a metal material, and an yttrium oxide film is formed on a contact surface of the ring member with the transport tray. 5. The heat treatment furnace according to claim 4, wherein a yttrium oxide film is formed on an upper surface of the transport tray which is in contact with the object to be processed. 6. The heat treatment furnace according to claim 5, wherein the carrying tray is made of a metal material. 7. The heat treatment furnace according to claim 5, wherein the carrying tray is made of a carbon-based composite material.