JP2000088474A - Heat treatment furnace - Google Patents

Abstract

(57) [Summary] [Problem] To extend the life of a C / C when part or all of a structural material, ancillary material or a jig material loading jig used in a furnace is used. To be able to achieve. SOLUTION: When a carbon fiber reinforced carbon composite material is used for a part or all of a structural material, an auxiliary material, or a processed product loading jig material used in a furnace, Oxides in the voids of the above materials,
Impregnation with ceramics or graphite powder or the like is performed to prevent the evaporated metal in the furnace from entering the voids of the material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment furnace in which a carbon fiber reinforced carbon composite material is used for a part or the whole of a structural material or a jig for loading a treated product used in the heat treatment furnace. The present invention relates to a heat treatment furnace in which measures for extending the life of the above structural material or jig material are taken.

[0002]

2. Description of the Related Art FIG. 1 shows a conventional heat treatment furnace. In the heat treatment furnace of FIG. 1, reference numeral 1 denotes a batch type vacuum furnace as an example of a vacuum heating furnace. Reference numeral 2 denotes a furnace shell of the vacuum furnace, which is a cylindrical main body 3 and a cooling facility surrounding wall connected to one end of the main body 3.
3a, and a door 4 provided at an entrance on the opposite side. Each of these is constituted by, for example, a water-cooled jacket. Reference numeral 5 denotes a heat insulating wall provided as needed.
And a door 7 provided at the doorway of the main body 6 and a door 8 provided on the side opposite to the door 7, and the inner space is a heat treatment chamber. The door 8 is closed when the processed product is heated and opened when cooled. Reference numeral 10 denotes a mounting table provided in the heat treatment chamber, and a space above the mounting table is a storage space 11 for processing products. Reference numeral 12 denotes a heating means disposed around the existing space 11, and an electric heater is used as an example, and is attached to a heat insulating wall. Reference numeral 18 denotes an exhaust pipe connecting the inside of the furnace shell 2 and a vacuum device 17 (not shown). Although not shown, a gas supply means (nozzle, etc.) (not shown) for supplying a heat treatment gas (for example, hydrogen or a reactive gas) corresponding to the heat treatment of the treated product to the furnace shell 2 and an outlet, Attached materials such as windows are installed.

[0003] Next, reference numeral 21 shows a well-known cooling structure of a processed product, and the accompanying materials provided therein will be described below. twenty two
Is a cooler, and 23 is a circulation fan, which is driven by a fan motor 24. 25 is a motor cover for holding a vacuum.

Next, the processing of the processed product 31 using the above vacuum furnace will be described. The processed product 31 is placed on a processed product shelf 30 placed on a tray 26. In the shelf 30, reference numeral 27 denotes a shelf plate, and reference numeral 28 denotes a support column. If the processed product is a small item, it is placed in a case 31. In the processing of such a processed product, the doors 4 and 7 are opened, and the processed product 31 is placed on a well-known roller (not shown) from the left side in FIG. 1 and is moved toward the mounting table 10. It is put on. Next, doors 4 and 7 are closed,
The vacuum device 17 is operated to evacuate the inside of the furnace shell 2 and, at the same time, heat is generated by energizing the heater 12, and
Heating of 31 is started.

When the processing product 31 is heated to a predetermined value, the power supply to the heater 12 is stopped, a cooling gas is introduced into the furnace shell 2, and the cooler 22 and the fan 23 are operated in a well-known manner. The operation is performed to cool the processed product 31. When the cooling is completed, the doors 4 and 7 are opened to take out the processed product 31 which has been processed.

In the heat treatment furnace 1, the heat insulating wall 5, the roll member, the heater member 12, the hearth 10, the structural members such as the doors 7, 4, and 8; the fan member 23; Jigs such as tray materials 26 for loading processed products, tray materials 26 for loading processed products, case members 31 for storing small processed products, and processed product shelves 30 supporting case members Is used. With respect to the above-mentioned structural materials, auxiliary materials or jigs for loading processed products in which the heat-resistant materials are used in the above-mentioned furnaces, recently, some or all of the heat-resistant materials are C / C composites (Carbon Fiber / Carbon composites). M
Carbon fiber reinforced carbon composite material (hereinafter also referred to simply as C / C) widely known as atrix composite is used. This C / C had excellent mechanical strength, heat resistance, thermal shock resistance, etc. as compared with conventional carbon, and seemed to have extremely excellent properties as an internal material for the heat treatment furnace.

[0007]

However, the above C / C
When used inside a heat treatment furnace, there is a problem that the members are damaged in a very short period of time, resulting in a change in shape, or a sudden deterioration in strength, which suddenly hinders the operation of the furnace. there were. In particular, the tendency is large in a jig such as a treated product case or a tray which reciprocates inside and outside the furnace every time, or in a furnace inside member of the single-chamber type furnace shown in FIG. This is because carbon / carbon reinforced C / C has fine voids resulting from its structure,
Metals and the like generated (evaporated) from the processing product in the furnace enter and accumulate in the voids, and the metallic fine substance reacts with O ₂ and H ₂ O to form oxides and the like, and the volume is reduced. It is thought that expansion occurs, causing the above-mentioned bad phenomena such as breakage of members and shape change. Such a concept is known in the related art, for example, even in a multi-chamber furnace such as a continuous vacuum furnace in which a front chamber, a main processing chamber, and a cooling chamber are connected, the inside of the furnace is not repaired. Open to the atmosphere. In addition, there is a problem that the same phenomenon occurs gently because air enters the furnace due to a leak or the like.

[0008] It is considered that the volume expansion of metals in the voids occurs as follows. For example, when the processed product 31 is heat-treated on the mounting table 10, the processed product 31
(Ca) remaining in the furnace escapes into the atmosphere gas in the furnace. Then, those Ca become the aforementioned C / C
Infiltrate and accumulate in the fine voids in Next, Ca is O
Contacting the ₂ and H ₂ O. As a result, 2Ca and O ₂ react to form 2CaO, and the CaO and H ₂ O react to form Ca (O
H) It becomes ₂ . Then, the volume of Ca increases under the following circumstances. For example, when expressed as a volume per mole, the above CaO = 16.6 (cm ³ / mol) becomes 33 when Ca (OH) ₂ is obtained.
(Cm ³ / mol), which is about double in volume. The amount of Ca that has entered the gap in this manner increases in the gap and destroys the inside of the C / C.

The heat treatment furnace of the present application is provided to solve the above-mentioned problems of the prior art. The purpose of the present application is to provide a heat treatment furnace in which C / C is used for part or all of the structural material, ancillary material, or a processed product loading jig used in the furnace. It is an object of the present invention to provide a heat treatment furnace having a longer life. Another object is to extend the life by previously impregnating the voids of the material with oxides, ceramics, graphite powder or the like to prevent the vaporized metal in the furnace from entering the voids of the material. It is an object of the present invention to provide a heat treatment furnace as described above. Other objects and advantages will be more readily apparent from the drawings and the following description associated therewith.

[0010]

According to the heat treatment furnace of the present invention, a carbon fiber reinforced carbon composite material is used for a part or the whole of a structural material, an auxiliary material or a jig for loading a processed product used in the furnace. In the heat treatment furnace, the voids of the material are previously impregnated with oxides, ceramics, graphite powder, or the like for the material, so that the evaporated metal in the furnace is prevented from entering the voids of the material. It is like that.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
This will be described with reference to FIG. FIG. 1 exemplifying a conventional heat treatment furnace
In a single-chamber furnace such as a furnace and in a continuous vacuum furnace mentioned above as a conventional example, various types of heat-resistant materials are used for structural materials, accessories, or jigs for loading processed products in the furnace. I have. This embodiment is directed to a heat treatment furnace in which a carbon fiber reinforced carbon composite material is used for some or all of these heat-resistant materials.

As described above, the carbon fiber reinforced carbon composite material is called C / C and is widely known. These recipes are
For example, after impregnating a carbon fiber base material with a phenolic resin or pitch, and molding and curing, it is manufactured by a method of carbonizing in an inert atmosphere, or a hydrocarbon such as methane or propane, at a relatively low concentration, Introduced into a carbon fiber substrate held at a high temperature and directly deposits carbon in the gas phase.Also, a unique filamentous shape coated with a resin in which a matrix component is previously included in a fiber bundle of carbon fibers. It is known that an intermediate material (preformed yarn) is manufactured, and it is manufactured by a method in which the intermediate material is processed as it is or woven into a sheet, hot-pressed, and then fired as necessary. However, in the C / C by any of these manufacturing methods, minute gaps are generated in the above product.

In the present embodiment, the oxides, arbitrary ceramics containing silicon, graphite powder, etc. are substantially oxidized and expanded even with the passage of time in the minute gaps generated in the C / C. The missing material is pre-impregnated. Then, as described above, the possibility that a substance such as a metal which is easily oxidized and expanded enters the minute gaps generated in the C / C is reduced, and the above C used in the heat treatment furnace is reduced.
Even if the / C material is used for a long time, that is, even if it comes into contact with O ₂ and H ₂ O, the deposits in the minute gaps do not expand due to the reaction, and C / C is used for a long life.

[0014]

As described above, the present invention relates to a carbon fiber reinforced carbon composite material used for a structural material used in a furnace, an auxiliary material or a jig material loading jig material. Oxides in the voids of the above materials,
By impregnating ceramics or graphite powder or the like to prevent the vaporized metal in the furnace from entering the voids of the above-described material, fine particles such as metal are filled in the minute voids of the carbon fiber reinforced carbon composite material. To prevent the accumulation of
It has the effect of eliminating the problems associated with its presence, extending the life of the carbon fiber reinforced carbon composite material, and thereby increasing the possibility of long-term safe use of the heat treatment furnace.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a vacuum furnace.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum furnace 2 Furnace shell 3 Main body of furnace shell 4 Door 5 Insulating wall 6 Main body of insulating wall 7 Door 8 Door 10 Mounting table (hearth floor) 11 Storage space 12 Heating means 18 Exhaust line 21 Cooling structure 22 Cooler 23 Fan 24 Fan motor 25 Motor cover 26 Tray 27 Shelf 28 Support post 30 Treated product shelf 31 Treated product

Claims (1)

[Claims] 1. A heat treatment furnace in which a carbon fiber reinforced carbon composite material is used for a part or all of a structural material, an auxiliary material, or a processing product loading jig material used in the furnace. Is previously impregnated with oxides, ceramics or graphite powder in the voids of the above materials,
A heat treatment furnace characterized in that the evaporated metal in the furnace is prevented from entering the voids of the material.