Heat resistant structure and member for heat treatment furnace

Abstract

Provided is a heat resistant structure which can be simply manufactured, has excellent mechanical characteristics under a high-temperature environment, and is hardly thermally deformed.　This heat resistant structure 1 comprises: a core material 2 composed of a plurality of C / C composite members 4; and a shell material 3 which covers at least a part of a surface 2a of the core material 2 and is composed of a metal.

Description

Heat-resistant structures and components for heat treatment furnaces

[0001] The present invention relates to a heat-resistant structure and a heat treatment furnace component using the heat-resistant structure.

[0002] Conventionally, metal materials have been widely used for heat treatment furnace components. However, metal bars have problems such as being heavy and prone to thermal deformation when used at high temperatures. Therefore, the deformed bars require reworking after use. Therefore, as an alternative to such metal bars, bars in which carbon fiber reinforced carbon composite material (C / C composite) is placed inside a metal pipe have been investigated.

[0003] For example, Patent Document 1 below discloses a heat-resistant structural member made of a heat-resistant metal material and a carbon / carbon material. Patent Document 1 describes that the heat-resistant metal material forms an outer shell structure, and the carbon / carbon material forms a core member enclosed inside the outer shell structure. Patent Document 1 also describes that the outer shell structure is characterized by enclosing helium gas therein. Furthermore, Patent Document 2 below describes that, in a structure similar to Patent Document 1, the outer shell structure is characterized by enclosing a reducing agent that reduces at least water and / or carbon oxides therein.

[0004] JP 2018-39708 A JP 2017-77998 A

[0005] However, in components in which a C / C composite is placed inside a metal pipe, a thick C / C composite is often required. However, the thicker the C / C composite, the more difficult it is to manufacture, resulting in low productivity. Another problem is that thicker C / C composites increase manufacturing costs. Furthermore, after processing thicker C / C composites, thin scraps are discarded, which poses environmental problems.

[0006] An object of the present invention is to provide a heat-resistant structure that can be easily manufactured, has excellent mechanical properties in high-temperature environments, and is less susceptible to thermal deformation, and a heat treatment furnace component that uses the heat-resistant structure.

[0007] The heat-resistant structure according to the present invention is characterized by comprising a core material made of a plurality of C / C composite members, and a shell material made of metal and covering at least a portion of the surface of the core material.

[0008] In the present invention, the core material is preferably a laminate of the plurality of C / C composite members.

[0009] In the present invention, the C / C composite member preferably has a substantially rectangular plate shape.

[0010] In the present invention, the C / C composite member is preferably a two-way C / C composite member.

[0011] In the present invention, when a load is applied to the heat-resistant structure, it is preferable that the C / C composite member is arranged so that the direction in which the longest side in a cross section along the width direction extends is approximately the same as the direction in which the load is applied.

[0012] In the present invention, it is preferable that when a load is applied to the heat-resistant structure, the plurality of C / C composite members are stacked in a direction substantially perpendicular to the direction in which the load is applied.

[0013] In the present invention, it is preferable that the shell material is a pipe made of metal, and that the plurality of C / C composite members are filled in the pipe.

[0014] In the present invention, it is preferable that the cross section of the pipe is substantially polygonal.

[0015] In the present invention, the cross-sectional shape of the pipe may be substantially circular.

[0016] In the present invention, it is preferable that the wall thickness of the pipe is 0.1 mm or more and 3 mm or less.

[0017] In the present invention, it is preferable that the filling rate of the C / C composite material in the pipe is 70% or more.

[0018] In the present invention, it is preferable that the shell material partially covers the surface of the core material.

[0019] In the present invention, the heat-resistant structure is preferably used in a non-oxidizing atmosphere.

[0020] A heat treatment furnace component according to the present invention is characterized by including a heat-resistant structure constructed according to the present invention.

[0021] According to the present invention, it is possible to provide a heat-resistant structure and a heat treatment furnace component using the heat-resistant structure, which can be easily manufactured, have excellent mechanical properties in high-temperature environments, and are less likely to undergo thermal deformation. Furthermore, the use of thin scrap metal also makes it possible to consider the global environment.

[0022] FIG. 1( a) is a schematic cross-sectional view along the length direction of a heat-resistant structure according to a first embodiment of the present invention, and FIG. 1( b) is a schematic cross-sectional view along the width direction of a heat-resistant structure according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view along the width direction of a heat-resistant structure according to a first modified example of the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view along the length direction of a heat-resistant structure according to a second modified example of the first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view along the width direction of a heat-resistant structure according to a second embodiment of the present invention. FIG. 5 is a schematic cross-sectional view along the width direction of a heat-resistant structure according to a third embodiment of the present invention. FIG. 6 is a schematic cross-sectional view along the width direction of a heat-resistant structure according to a fourth embodiment of the present invention. FIG. 7 is a diagram for explaining lengths L1 and L2 in a heat-resistant structure according to the third embodiment of the present invention. FIG. 8 is a schematic perspective view showing a heat-resistant structure according to a fifth embodiment of the present invention. FIG. 9 is a schematic cross-sectional view along the width direction of a heat-resistant structure prepared in Example 1. FIG. 10 is a schematic cross-sectional view along the width direction of a heat-resistant structure prepared in Example 4. Fig. 11 is a schematic cross-sectional view along the width direction of the heat-resistant structure produced in Example 8. Fig. 12 is a schematic cross-sectional view along the width direction of the heat-resistant structure produced in Example 9. Fig. 13 is a schematic cross-sectional view along the width direction of the heat-resistant structure produced in Example 10. Fig. 14 is a schematic cross-sectional view along the width direction of the heat-resistant structure produced in Example 11. Fig. 15 is a schematic cross-sectional view along the width direction of the heat-resistant structure produced in Reference Example 1.

[0023] The present invention will be described in detail below.

[0024] (First embodiment) Fig. 1(a) is a schematic cross-sectional view along the length direction of a heat-resistant structure according to a first embodiment of the present invention. Fig. 1(b) is a schematic cross-sectional view along the width direction of a heat-resistant structure according to the first embodiment of the present invention. The length direction of the heat-resistant structure 1 is the Z direction shown in Figs. 1(a) and 1(b). The width direction of the heat-resistant structure 1 is the Y direction shown in Figs. 1(a) and 1(b).

[0025] 1(a) and 1(b), the heat-resistant structure 1 includes a core material 2 and a shell material 3. The shell material 3 covers a surface 2a of the core material 2.

[0026] In this embodiment, the shell material 3 is a metal pipe. The inside of this shell material 3 is filled with a core material 2 made of four C / C composite members 4. In this embodiment, a heat-resistant structure 1, which is a bar for a heat treatment furnace, is thereby constructed. Note that "C / C composite" refers to a carbon fiber reinforced carbon composite material. In this embodiment, a two-directional C / C composite (2DC / C composite) member having a two-dimensional structure is used as the C / C composite member 4.

[0027] In this embodiment, a load is applied to the heat-resistant structure 1 in the direction of an arrow O shown in Fig. 1(b) . Therefore, in this embodiment, the load is applied in the X direction shown in Figs. 1(a) and 1(b) .

[0028] 1(b), each of the C / C composite members 4 constituting the core material 2 has a substantially rectangular plate shape. In addition, in a cross section along the width direction Y, each C / C composite member 4 is arranged so that the direction in which the longest side 4a of the C / C composite member 4 extends is substantially the same as the X direction in which a load is applied. In this embodiment, the C / C composite members 4 are also arranged so that the fiber direction is substantially the same as the X direction in which a load is applied.

[0029] In this embodiment, the C / C composite members 4 are stacked along the Y direction, which is approximately perpendicular to the X direction in which the load is applied. This configuration forms the core material 2. In this specification, "approximately the same direction" refers not only to a completely identical direction, but also to a range tilted by ±5° from the same direction. Furthermore, "approximately perpendicular direction" refers not only to a completely perpendicular direction, but also to a range tilted by ±5° from the perpendicular direction.

[0030] As described above, in the heat-resistant structure 1 of this embodiment, the core material 2 composed of the C / C composite material 4 is provided inside the shell material 3, which is a metal pipe. This improves the mechanical properties of the heat-resistant structure 1 in high-temperature environments and makes it less susceptible to thermal deformation. Furthermore, since multiple C / C composite materials 4 can be disposed inside the shell material 3, the thickness of each C / C composite material 4 can be reduced. The heat-resistant structure 1 can be manufactured simply by disposing multiple C / C composite materials 4 inside the shell material 3, which simplifies manufacturing and increases productivity. Furthermore, the use of thin C / C composite materials 4 reduces manufacturing costs.

[0031] In this embodiment, the cross-sectional shape of the metal pipe constituting the shell material 3 is approximately square. However, the cross-sectional shape of the shell material 3 is not particularly limited, and may be approximately polygonal or approximately circular. In particular, the cross-sectional shape of the metal pipe is preferably approximately rectangular, including rectangular. In this case, the filling rate of the C / C composite member 4 can be further increased.

[0032] The thickness of the shell material 3 is not particularly limited, but is preferably 0.1 mm or more and preferably 3 mm or less. When the thickness of the shell material 3 is within the above range, the wear resistance against other metal members can be further improved.

[0033] The material of the shell material 3 is not particularly limited, but may be, for example, SUS. Alternatively, a metal material that is less reactive with SUS or carbon and is used for heat treatment may be used. Such a metal material is not particularly limited, but may be, for example, STKMR (square steel pipe for machine structures) or STPG (carbon steel pipe for pressure piping).

[0034] In the heat-resistant structure 1 of this embodiment, four C / C composite members 4 are arranged inside the shell material 3. However, the number of C / C composite members 4 arranged inside the shell material 3 is not particularly limited, and can be determined appropriately depending on the thickness of the C / C composite members 4.

[0035] The number of C / C composite members 4 arranged inside the shell material 3 is preferably two or more, more preferably three or more, and can be preferably six or less, more preferably five or less.

[0036] The filling rate of the C / C composite material 4 disposed inside the shell material 3 is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. In this case, the mechanical properties in a high-temperature environment can be further improved, and thermal deformation can be made even less likely to occur. The filling rate of the C / C composite material 4 disposed inside the shell material 3 may be 100%.

[0037] 1B, in the heat-resistant structure 1 of this embodiment, the thickness b of each C / C composite member 4 is the same. The thickness b of the C / C composite member 4 is not particularly limited, but may be, for example, 0.5 mm or more and 12 mm or less.

[0038] However, the thicknesses of the C / C composite members 4A, 4B may be different, as in the heat-resistant structure 1A of the first modification shown in Fig. 2. In the first modification shown in Fig. 2, the thickness of the two C / C composite members 4A on the central side is greater than the thickness of the four C / C composite members 4B on the end sides.

[0039] In the heat-resistant structure 1 of this embodiment, as shown in Fig. 1(a), the entire surface 2a of the core material 2 along the longitudinal direction Z is covered with the shell material 3. On the other hand, the end faces 2b and 2c are not covered with the shell material 3. Therefore, the generated air can escape to the outside, further reducing the risk of rupture and the like.

[0040] 3, the shell material 3 may be partially hollowed out, or the shell material 3 may be disposed only at the wear points, thereby making it possible to further reduce the weight of the heat resistant structure 1B.

[0041] In the heat-resistant structure 1 of this embodiment, a mark may be provided on the main surface 1a to which a load is applied. Other methods for identifying the main surface 1a to which a load is applied include drilling pin holes, adjusting the direction of the weld, processing the metal pipe and the C / C composite member 4, and providing marks. In this case, the direction of use can be made even clearer, and workability can be further improved.

[0042] In the heat-resistant structure 1 of this embodiment, a commercially available C / C composite material 4 can be used as the C / C composite material 4 constituting the core material 2. The C / C composite material 4 may also be manufactured by the following method.

[0043] Specifically, first, carbon fibers are impregnated with a thermosetting resin composition and molded to obtain a molded body.

[0044] Examples of carbon fibers that can be used include polyacrylonitrile-based carbon fibers (PAN-based carbon fibers) and pitch-based carbon fibers. It is preferable to use carbon fibers aligned in two directions to form a 2DC / C composite. The thermosetting resin composition may be composed of only a thermosetting resin, or may contain a thermosetting resin and an additive. The thermosetting resin composition may also contain pitch. Furthermore, it is preferable to mold the molded body by pultrusion molding. In this case, it is easier to align the carbon fibers in one direction, and a molded body with a higher carbon fiber volume content can be obtained. The shape of the molded body is not particularly limited, but can be, for example, a flat plate, a square bar, or a round bar.

[0045] The 2DC / C composite may also be obtained by arranging prepregs in which carbon fiber tows are impregnated with a thermosetting resin such as a phenolic resin and molding the prepregs in a mold.

[0046] Next, the molded body is baked to carbonize the thermosetting resin composition, thereby obtaining a 2DC / C composite.

[0047] The firing step is preferably carried out in a non-oxidizing atmosphere such as a nitrogen gas atmosphere to prevent oxidation of the 2DC / C composite during normal production.

[0048] The firing temperature is not particularly limited, but can be, for example, 700° C. or higher and 1300° C. or lower. The firing time is not particularly limited, but can be, for example, the maximum temperature holding time is 30 minutes or higher and 600 minutes or lower.

[0049] Furthermore, the pitch impregnation / sintering process may be repeated to obtain a 2DC / C composite with even higher density. The pitch impregnation / sintering process may be repeated, for example, one or more times and up to ten times.

[0050] The present invention may further include a densification step of densifying at least a portion of the open pores in the 2DC / C composite, which can further suppress oil penetration and oxidative wear.

[0051] The densification step may be, for example, a step of impregnating open pores of the 2DC / C composite with pitch or a thermosetting resin and carbonizing the composite.

[0052] The densification step may be a step of performing a CVI treatment.

[0053] The densification step may be a step of impregnating open pores of the 2DC / C composite with molten silicon to convert it into silicon carbide.

[0054] The densification step may also be a step of impregnating the open pores of the 2DC / C composite with aluminum phosphate and then heat treating the composite.

[0055] These densification steps may be used alone or in combination.

[0056] Second to Fourth Embodiments Fig. 4 is a schematic cross-sectional view along the width direction of a heat-resistant structure according to a second embodiment of the present invention. As shown in Fig. 4, four C / C composite members 24A to 24D are disposed within a shell material 3 in a heat-resistant structure 21. Each of the C / C composite members 24A to 24D has the same size and a substantially square cross-sectional shape. Two DC / C composite members 24A and 24C, whose fiber direction is substantially the same as the X direction in which a load is applied, and two DC / C composite members 24B and 24D, whose fiber direction is substantially perpendicular to the X direction in which a load is applied, are disposed adjacent to each other. Other aspects are similar to those of the first embodiment.

[0057] FIG. 5 is a schematic cross-sectional view along the width direction of a heat-resistant structure according to a third embodiment of the present invention.

[0058] As shown in Figure 5, the heat-resistant structure 31 has five C / C composite members 34A to 34E arranged within the shell material 3. In the heat-resistant structure 31, four substantially rectangular C / C composite members 34B to 34E are arranged to surround one substantially square C / C composite member 34A in cross section. Furthermore, C / C composite members 34B and 34D, whose longest sides and fiber directions are substantially the same as the X direction in which a load is applied, and C / C composite members 34C and 34E, whose longest sides and fiber directions are substantially perpendicular to the X direction in which a load is applied, are arranged adjacent to each other. Other aspects are similar to those of the first embodiment.

[0059] FIG. 6 is a schematic cross-sectional view along the width direction of a heat-resistant structure according to a fourth embodiment of the present invention.

[0060] 6, in the heat-resistant structure 41, two C / C composite members 44 are disposed within the shell material 3. In the heat-resistant structure 41, each C / C composite member 44 is disposed so that the direction in which the longest side extends and the fiber direction are aligned in the Y direction, which is substantially perpendicular to the X direction in which a load is applied. Other points are the same as those in the first embodiment.

[0061] As shown in the second to fourth embodiments, the position of each C / C composite member within the shell material is not particularly limited. In any case, a core member composed of a C / C composite member is provided inside the shell material, which is a metal pipe, thereby improving the mechanical properties of the heat-resistant structure in high-temperature environments and reducing thermal deformation. Furthermore, since multiple C / C composite members can be arranged inside the shell material, the thickness of each C / C composite member can be reduced. Since the heat-resistant structure can be manufactured simply by arranging multiple C / C composite members inside the shell material, manufacturing is easy and productivity can be improved. Furthermore, the use of thin C / C composite members reduces manufacturing costs.

[0062] However, in the present invention, it is preferable that the direction in which the longest side a extends is substantially the same as the X direction in which the load is applied, as shown in Fig. 1(b), for example. In this case, the mechanical properties of the heat-resistant structure 1 in a high-temperature environment can be further improved, and thermal deformation can be made even less likely to occur.

[0063] Furthermore, when the cross-sectional shape of the heat-resistant structure is substantially rectangular, as shown in FIG. 7 , the ratio (L1 / L2) of the length L1 of the C / C composite members 34A-34E along the X-direction along which a load is applied to the length L2 of the inner peripheral surface of the shell material 3 along the X-direction along which a load is applied is preferably 0.5 or greater, more preferably 0.75 or greater, and even more preferably 1. In this case, the mechanical properties of the heat-resistant structure 31 in high-temperature environments can be further improved, and thermal deformation can be further reduced. Note that the length L1 is the length of the C / C composite members 34B and 34D, which have the longest length along the X-direction along which a load is applied, among the five C / C composite members 34A-34E that make up the heat-resistant structure 31. The ratio (L1 / L2) is, for example, 1 in the first embodiment shown in FIGS. 1( a) and 1(b) and 0.5 in the second embodiment shown in FIG. 4.

[0064] Furthermore, in a plan view, the ratio (S1 / S2) of the area S1 where the C / C composite members 34B, 34D having the length L1 are arranged to the entire area S2 of the main surface 1a to which the load is applied is preferably 0.5 or more, more preferably 0.75 or more, and even more preferably 1. In this case, the mechanical properties of the heat-resistant structure 31 in a high-temperature environment can be further improved, and thermal deformation can be made even less likely to occur.

[0065] 7, when the C / C composite member 34A has the second longest length along the X direction in which a load is applied, the ratio (L3 / L2) is preferably 0.25 or more, more preferably 0.5 or more, and preferably 0.75 or less, where L3 is the length of the C / C composite member 34A. In this case, the mechanical properties of the heat-resistant structure 31 in a high-temperature environment can be further improved, and thermal deformation can be made even less likely to occur.

[0066] In addition, in a plan view, the ratio (S3 / S2) of the area S3 where the C / C composite member 34A having the length L3 is arranged to the entire area S2 of the main surface 1a to which a load is applied is preferably 0.5 or more and preferably 1 or less. In this case, the mechanical properties of the heat-resistant structure 31 in a high-temperature environment can be further improved, and thermal deformation can be made even less likely to occur.

[0067] 4, when the ratio (L1 / L2) is relatively small, the C / C composite members 24A to 24D may be fixed together with adhesive, pins, or screws. Alternatively, both ends of the shell material 3 may be welded together so as not to completely seal the shell material, thereby fixing both ends of the C / C composite members 24A to 24D. In this case, the mechanical properties of the heat-resistant structure 21 in a high-temperature environment can be further improved, and thermal deformation can be further reduced.

[0068] Fifth Embodiment Fig. 8 is a schematic perspective view showing a heat-resistant structure according to a fifth embodiment of the present invention. As shown in Fig. 8, the heat-resistant structure 51 is a basket for a heat treatment furnace. Similar to the heat-resistant structure 1 of the first embodiment, the heat-resistant structure 51 is configured by filling a core material 2 made of four C / C composite members 4 inside a shell material 3.

[0069] In the heat-resistant structure 51, a core material composed of a C / C composite material is provided inside a shell material, which is a metal pipe. This improves the mechanical properties of the heat-resistant structure 51 in high-temperature environments and makes it less susceptible to thermal deformation. Furthermore, since multiple C / C composite materials can be disposed inside the shell material, the thickness of each C / C composite material can be reduced. The heat-resistant structure 51 can be manufactured simply by disposing multiple such C / C composite materials inside the shell material, which simplifies manufacturing and increases productivity. Furthermore, the use of thin C / C composite materials reduces manufacturing costs.

[0070] Thus, the heat-resistant structure of the present invention can be suitably used as a heat treatment member such as a bar for a heat treatment furnace, a tray for a heat treatment furnace, or a basket for a heat treatment furnace.

[0071] Next, the present invention will be clarified by showing specific examples and comparative examples of the present invention, but the present invention is not limited to the following examples.

[0072] Example 1 In Example 1, a heat-resistant structure 61 (bar for heat treatment furnace) having the cross-sectional structure shown in Fig. 9 was produced. Specifically, a 1 mm-thick SUS square pipe (19 mm x 19 mm x 700 mm) was used as the shell material 3, and two 2DC / C composite members 64 (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 8.5 mm x 700 mm)) were inserted into the SUS square pipe to obtain the heat-resistant structure 61. The load direction was the direction indicated by arrow O in the drawing.

[0073] In Example 2, a heat-resistant structure 1 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 1 was produced. Specifically, four 2DC / C composite members 4 (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 4.25 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 1.

[0074] Example 3 In Example 3, a heat-resistant structure 1A (a bar for a heat treatment furnace) was produced having the cross-sectional structure shown in Fig. 2. Specifically, two 2DC / C composite members 4A (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 4.25 mm x 700 mm)) and four 2DC / C composite members 4B (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 2.125 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 1A.

[0075] Example 4 In Example 4, a heat-resistant structure 71 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 10 was produced. Specifically, eight 2DC / C composite members 74 (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 2.125 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 71.

[0076] Example 5 In Example 5, a heat-resistant structure 31 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 5 was produced. Specifically, one 2DC / C composite member 34A (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bar (8.5 mm x 8.5 mm x 700 mm)) and four 2DC / C composite members 34B to 34E (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bar (12.75 mm x 4.25 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 31.

[0077] Example 6 In Example 6, a heat-resistant structure 41 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 6 was produced. Specifically, two 2DC / C composite members 44 (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 8.5 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 41.

[0078] In Example 7, a heat-resistant structure 21 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 4 was produced. Specifically, four 2DC / C composite members 24A to 24D (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bar (8.5 mm x 8.5 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 21.

[0079] Example 8 In Example 8, a heat-resistant structure 81 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 11 was produced. Specifically, eight 2DC / C composite members 84 (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (8.5 mm x 4.25 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 81.

[0080] Example 9 In Example 9, a heat-resistant structure 91 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 12 was produced. Specifically, two 2DC / C composite members 94A (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 4.25 mm x 700 mm)) and four 2DC / C composite members 94B (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (8.5 mm x 4.25 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 91.

[0081] Example 10 In Example 10, a heat-resistant structure 101 (a bar for a heat treatment furnace) was produced having the cross-sectional structure shown in Fig. 13. Specifically, two 2DC / C composite members 104A (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 4.25 mm x 700 mm)) and four 2DC / C composite members 104B (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (8.5 mm x 4.25 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 101.

[0082] Example 11 In Example 11, a heat-resistant structure 111 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 14 was produced. Specifically, two 2DC / C composite members 114A (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (17 mm x 4.25 mm x 700 mm)) and four 2DC / C composite members 114B (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bars (8.5 mm x 2.125 mm x 700 mm)) were inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 111.

[0083] Reference Example 1 In Reference Example 1, a heat-resistant structure 121 (a bar for a heat treatment furnace) having the cross-sectional structure shown in Fig. 15 was produced. Specifically, one 2DC / C composite member 124 (manufactured by Toyo Tanso Co., Ltd., product number "CX-761", square bar (17 mm x 17 mm x 700 mm)) was inserted into the same SUS square pipe as in Example 1, to obtain the heat-resistant structure 121.

[0084] Comparative Example 1 In Comparative Example 1, a SUS square bar (19 mm x 19 mm x 700 mm) was used, into which no 2DC / C composite member was inserted.

[0085] [Evaluation] The structures of Examples 1 to 11, Reference Example 1, and Comparative Example 1 were heated in an electric furnace at 900°C for 5 hours with both ends supported in the load direction with a span of 600 mm and a 30 kg weight hanging from the center. After cooling, the weight was removed and the amount of deflection was measured.

[0086] The results are shown in Table 1 below. In Examples 1 to 11, the ratio (L1 / L2) of the length L1 of the longest side of the C / C composite member along the X direction along which the load is applied to the length L2 of the inner peripheral surface of the shell material along the X direction along which the load is applied is also shown. In Examples 5 and 9 to 11, the ratio (L3 / L2) of the length L3 of the second longest side of the C / C composite member along the X direction along which the load is applied to the length L2 of the inner peripheral surface of the shell material along the X direction along which the load is applied is also shown.

[0087]

[0088] As is clear from Table 1, it was confirmed that the heat-resistant structures obtained in Examples 1 to 11 have superior mechanical properties in high-temperature environments and are less susceptible to thermal deformation, compared to the SUS square bar of Comparative Example 1. In particular, it was confirmed that Examples 1 to 4, in which the ratio (L1 / L2) is 1, have mechanical properties that are approximately equivalent to those of Reference Example 1, which uses a single thick 2DC / C composite member 124.

[0089] DESCRIPTION OF SYMBOLS 1, 1A, 1B, 21, 31, 41, 51, 61, 71, 81, 91, 101, 111, 121... Heat-resistant structure 1a... Main surface 2... Core material 2a... Surface 2b, 2c... End surface 3... Shell material 4, 4A, 4B, 24A to 24D, 34A to 34E, 44, 64, 74, 84, 94A, 94B, 104A, 104B, 114A, 114B, 124... C / C composite member 4a... Side

Claims

1. A core material composed of a plurality of C / C composite members; A shell material covering at least a portion of the surface of the core material and made of metal; A heat resistant structure comprising:

2. The heat resistant structure according to claim 1 , wherein the core material is a laminate of the plurality of C / C composite members.

3. The heat resistant structure according to claim 1 or 2, wherein the C / C composite member has a substantially rectangular plate shape.

4. 3. The heat resistant structure according to claim 1 or 2, wherein the C / C composite member is a two-way C / C composite member.

5. When a load is applied to the heat-resistant structure, 3. The heat-resistant structure according to claim 1, wherein the C / C composite member is disposed so that a direction in which the longest side in a cross section along a width direction of the C / C composite member extends is substantially the same as a direction in which the load is applied.

6. When a load is applied to the heat-resistant structure, 3. The heat resistant structure according to claim 1, wherein the plurality of C / C composite members are laminated in a direction substantially perpendicular to a direction in which the load is applied.

7. The shell material is a pipe made of metal, 3. The heat resistant structure according to claim 1, wherein the pipe is filled with the plurality of C / C composite members.

8. The heat resistant structure according to claim 7 , wherein the cross-sectional shape of the pipe is substantially polygonal.

9. The heat resistant structure according to claim 7 , wherein the cross-sectional shape of the pipe is substantially circular.

10. 8. The heat resistant structure according to claim 7, wherein the wall thickness of the pipe is 0.1 mm or more and 3 mm or less.

11. The heat resistant structure according to claim 7 , wherein a filling rate of the C / C composite member in the pipe is 70% or more.

12. The heat-resistant structure according to claim 1 or 2, wherein the shell material partially covers a surface of the core material.

13. The heat-resistant structure according to claim 1 or 2, which is used in a non-oxidizing atmosphere.

14. A member for a heat treatment furnace, comprising the heat resistant structure according to claim 1 or 2.