JP2019196518A - Manufacturing method of carburized component - Google Patents

Abstract

To suppress as much as possible deformation caused by a carburization treatment, when manufacturing a carburized component by carburizing a high-melting metal component.SOLUTION: A method for manufacturing a carburized component by carburizing a high-melting metal component (20) includes following procedures. The high-melting metal component is held between a first holding member (21) and a second holding member (22) which are both rigid bodies, and either or both of which have a function as a carbon supply source. Hereby, a laminate (S) of the first holding member, the high-melting metal component and the second holding member is formed. Subsequently, the laminate is subjected to a carburization treatment, while being heated.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method of manufacturing a carburized part by carburizing a refractory metal part.

  For parts formed of a refractory metal such as tantalum, for example, carburizing treatment may be performed to improve durability. During the carburizing process, a high temperature (for example, a temperature of 2000 ° C. or higher) is applied to the part for a long time. For this reason, even if the heating temperature is lower than the melting point, there is a concern that the component is deformed to a degree that deviates from a desired size or shape.

  In this regard, for example, Patent Document 1 discloses a carburizing method for a tantalum member having a flat portion. Such a method includes the following steps. (1) The process which arrange | positions a tantalum member in the chamber in which a carbon source exists by supporting a plane part with the some support rod in which the front-end | tip part was formed in the taper shape. (2) A step of subjecting the carbon from the carbon source to infiltrate from the surface of the tantalum member and subjecting it to carburizing treatment by reducing the pressure in the chamber and heating.

JP 2010-280948 A

  When manufacturing a carburized part by carburizing a refractory metal part, as described in Patent Document 1, it is required to suppress deformation due to carburization as much as possible. The present invention has been made in view of the circumstances exemplified above.

The manufacturing method of the carburized component (10) according to claim 1 is a method of manufacturing the carburized component by carburizing the refractory metal component (20).
Such a manufacturing method includes the following processes.
By sandwiching the refractory metal part between the first clamping member (21) and the second clamping member (22), both of which are rigid bodies, the first clamping member, the refractory metal part, and the second clamping Forming a laminate (S) with the member,
The laminated body is carburized while being heated.

  In such a manufacturing method, the refractory metal parts are sandwiched between the first sandwiching member and the second sandwiching member, both of which are rigid bodies, during the carburizing process. Therefore, deformation of the refractory metal part due to heating during the carburizing process can be suppressed as much as possible.

  In each column of the application document, when each element is given a reference numeral in parentheses, the reference numeral simply indicates a correspondence relationship between the element and a specific configuration described in an embodiment described later. An example is shown. Therefore, the present invention is not limited by the description of the reference symbols.

It is a sectional side view which shows schematic structure of the carburized component which concerns on 1st embodiment. It is a sectional side view which shows the outline of the manufacturing method of the carburized component shown by FIG. It is a sectional side view which shows schematic structure of the carburized component which concerns on 2nd embodiment. It is a sectional side view which shows the outline of the manufacturing method of the carburized component shown by FIG. It is a top view which shows schematic structure of the refractory metal component shown by FIG. It is a top view which shows schematic structure of the 1st clamping member shown by FIG. It is a top view which shows schematic structure of the 2nd clamping member shown by FIG. It is a sectional side view which shows the outline of the manufacturing method which concerns on 3rd embodiment. It is a sectional side view which shows schematic structure of the carburized component which concerns on 4th embodiment. FIG. 10 is a side sectional view showing an outline of a method of manufacturing the carburized component shown in FIG. 9.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that various modifications that can be applied to one embodiment may interfere with understanding of the embodiment if inserted in the middle of a series of descriptions related to the embodiment. It is described collectively after the explanation.

(First embodiment)
First, a schematic configuration of the carburized component 10 according to the first embodiment will be described with reference to FIG. In the present embodiment, the carburized component 10 has a plate shape or a block shape.

  In the present embodiment, the carburized component 10 is formed by performing a carburizing process on a component formed of tantalum or a tantalum alloy that is a refractory metal. That is, the central portion 11 of the carburized component 10 is made of tantalum or a tantalum alloy. On the other hand, a carburized layer 12 is formed around the central portion 11.

  Hereinafter, the manufacturing method of the carburized component 10 shown in FIG. 1 will be described with reference to FIG. For convenience of explanation, right-handed XYZ orthogonal coordinates are set as shown in FIG. In FIG. 2, the downward direction, that is, the negative Z-axis direction is assumed to be the direction of gravity action.

  First, a plate-shaped or block-shaped refractory metal part 20 formed of tantalum or a tantalum alloy before carburizing is prepared. Moreover, the 1st clamping member 21 and the 2nd clamping member 22 which are rigid bodies and are plate shape or block shape are prepared. In the present embodiment, one or both of the first clamping member 21 and the second clamping member 22 have a function as a carbon supply source. Specifically, the first clamping member 21 and the second clamping member 22 are formed of a graphite material so that both have a function as a carbon supply source.

  Next, the refractory metal component 20 is sandwiched between the first sandwiching member 21 and the second sandwiching member 22, so that the laminated body of the refractory metal component 20, the first sandwiching member 21, and the second sandwiching member 22. S is formed. The stacking direction in the stacked body S is shown as a stacking axis L1 in the drawing. That is, the laminated body S is obtained by arranging the first sandwiching member 21, the refractory metal component 20, and the second sandwiching member 22 in this order in the stacking direction.

Subsequently, as shown in FIG. 2, the stacked body S is put into the heating furnace 30. Specifically, in the present embodiment, the stacked body S is placed on a placing table 31 made of a heat-resistant material in the heating furnace 30. The upper surface of the mounting table 31 is held almost horizontally. That is, the stacking direction of the stacked body S is a direction along the gravity action direction. Specifically, the angle formed by the stacking direction of the stacked body S and the direction of gravity action is about 0 to 10 degrees. Further, a heat resistant member 40 having a density of 1.5 g / cm ³ or more is placed on the laminate S.

  Subsequently, the stacked body S put in the heating furnace 30 is heated in the heating furnace 30. The heating temperature is, for example, 2000 ° C. or higher. Then, the first sandwiching member 21 and the second sandwiching member 22 located on both sides of the refractory metal component 20 function as a carbon supply source, so that carbon enters from the surface side of the refractory metal component 20. In this way, the carburizing process is performed.

  As described above, in the manufacturing method of the present embodiment, the refractory metal component 20 is sandwiched between the first sandwiching member 21 and the second sandwiching member 22 that are both rigid bodies during the carburizing process. Thereby, the deformation | transformation of the high melting-point metal component 20 during a carburizing process can be suppressed as much as possible. Therefore, according to the present embodiment, it is possible to stably manufacture the carburized component 10 having a desired shape.

  In the present embodiment, the refractory metal part 20, the first clamping member 21, and the second clamping member 22 have a plate shape or a block shape. Moreover, the laminated body S arranges the 1st clamping member 21, the high melting-point metal component 20, and the 2nd clamping member 22 in the lamination direction in this order. Furthermore, the manufacturing method of the present embodiment performs the carburizing process in a state where the stacking direction in the stacked body S is along the gravity action direction. Therefore, the deformation of the refractory metal component 20 during the carburizing process can be suppressed even better.

In the manufacturing method according to the present embodiment, the carburizing process is performed with the heat-resistant member 40 having a density of 1.5 g / cm ³ or more placed on the laminate S. Therefore, the refractory metal component 20 can be favorably held between the first clamping member 21 and the second clamping member 22 during the carburizing process.

(Second embodiment)
In the following description of the second embodiment, only different parts from the first embodiment will be described. In the first embodiment and the second embodiment, the same or equivalent parts are denoted by the same reference numerals. Therefore, in the following description of the second embodiment, regarding the components having the same reference numerals as those in the first embodiment, the description in the first embodiment can be incorporated as appropriate unless there is a technical contradiction or special additional description.

  Referring to FIG. 3, in the present embodiment, the carburized component 10 is formed in a cylindrical shape having a symmetry axis L <b> 2, specifically, a cylindrical shape. Similarly, referring to FIG. 4, the first clamping member 21 and the second clamping member 22 are formed in a cylindrical shape having a symmetry axis L <b> 2, specifically in a cylindrical shape. The laminate S is formed by housing the refractory metal component 20 inside the first sandwiching member 21 and housing the second sandwiching member 22 inside the refractory metal component 20.

Also in this embodiment, the 1st clamping member 21 and the 2nd clamping member 22 are formed with the graphite material so that both may have a function as a carbon supply source. In the present embodiment, the thermal expansion coefficient of the first clamping member 21 is equal to or lower than the thermal expansion coefficient of the second clamping member 22. Specifically, the thermal expansion coefficient of the first clamping member 21 is C1, and the thermal expansion coefficient of the second clamping member 22 is C2, C1 = 2.5 to 5.0 × 10 ⁻⁶ [1 / K], C2 = 5.0 to 6.6 × 10 ⁻⁶ [1 / K]. The thermal expansion coefficient of the graphite material can be easily adjusted, for example, by changing the sintering conditions.

  As shown in FIG. 5, the outer diameter of the refractory metal part 20 is D0 and the inner diameter is d0. Further, as shown in FIG. 6, the inner diameter of the first clamping member 21 is d1. Furthermore, as shown in FIG. 7, the outer diameter of the second clamping member 22 is D2. In this case, in this embodiment, D0 = 80 to 160 [mm], d0 = 77 to 157 [mm], d1 = D0 + α, α = 1.5 to 5 [mm], D2 = d0−β, β = 1.5 to 3 [mm].

  Hereinafter, the manufacturing method of the carburized component 10 shown in FIG. 3 will be described with reference to FIG. For convenience of explanation, in FIG. 4, right-handed XYZ orthogonal coordinates are set as shown. In FIG. 4, the downward direction, that is, the negative Z-axis direction is assumed to be the gravity action direction.

  First, a cylindrical refractory metal component 20 formed of tantalum or a tantalum alloy before carburizing is prepared. Moreover, the 1st clamping member 21 and the 2nd clamping member 22 which are rigid and cylindrical are prepared.

  Next, the refractory metal component 20 is sandwiched between the first sandwiching member 21 and the second sandwiching member 22, so that the laminated body of the refractory metal component 20, the first sandwiching member 21, and the second sandwiching member 22. S is formed. Specifically, the laminated body S is formed by housing the refractory metal component 20 inside the first sandwiching member 21 and housing the second sandwiching member 22 inside the refractory metal component 20. At this time, the refractory metal component 20 and the first clamping member 21 are substantially in close contact with each other. Similarly, the refractory metal part 20 and the second holding member 22 are substantially in close contact with each other.

  Subsequently, as shown in FIG. 4, the stacked body S is put into the heating furnace 30 with the symmetry axis L <b> 2 along the direction of gravity action. Specifically, the angle formed between the symmetry axis L2 and the direction of gravity action is about 0 to 3 degrees. Subsequently, the stacked body S put in the heating furnace 30 is heated in the heating furnace 30. The heating temperature is, for example, 2000 ° C. or higher. Thereby, a carburizing process is performed.

  As described above, also in the manufacturing method of the present embodiment, the refractory metal component 20 is sandwiched between the first sandwiching member 21 and the second sandwiching member 22 that are both rigid bodies during the carburizing process. Therefore, deformation of the refractory metal part 20 during the carburizing process can be suppressed as much as possible.

  In the present embodiment, the refractory metal part 20, the first clamping member 21, and the second clamping member 22 have a cylindrical shape having a symmetry axis L2, specifically, a cylindrical shape. The laminate S is formed by housing the refractory metal part 20 inside the first sandwiching member 21 and housing the second sandwiching member 22 inside the refractory metal part 20. Furthermore, the manufacturing method of this embodiment performs the carburizing process in a state in which the axis of symmetry L2 in the stacked body S is along the direction of gravity action. Therefore, deformation of the refractory metal part 20 during the carburizing process can be suppressed as much as possible.

In the manufacturing method of the present embodiment, the thermal expansion coefficient of the first clamping member 21 is equal to or less than the thermal expansion coefficient of the second clamping member 22. Specifically, C1 is the thermal expansion coefficient of the first clamping member 21, and C1 is 2.5 to 5.0 × 10 ⁻⁶ [1 / when the thermal expansion coefficient of the second clamping member 22 is C2. K], C2 = 5.0 to 6.6 × 10 ⁻⁶ [1 / K]. Furthermore, D0 = 80 to 160 [mm] of the refractory metal component 20, the inner diameter d0 = 77 to 157 [mm] of the refractory metal component 20, and the inner diameter d1 of the first clamping member 21 = D0 + α, α = 1.5 5 [mm], the outer diameter D2 of the second clamping member 22 = d0−β, and β = 1.5 to 3 [mm].

  Thereby, during the carburizing process, the sandwiched state of the refractory metal component 20 between the first sandwiching member 21 and the second sandwiching member 22 can be satisfactorily maintained. That is, the adhesion state between the refractory metal component 20 and the first and second clamping members 21 and 22 located on both sides thereof during the carburizing process can be maintained well. Therefore, deformation of the refractory metal part 20 during the carburizing process can be suppressed as much as possible. Moreover, the carburizing to the refractory metal component 20 during the carburizing process can proceed well.

  In the manufacturing method of the present embodiment, the carburizing process is performed in a state where the axis of symmetry L2 of the stacked body S is along the direction of gravity action. Specifically, during the carburizing process, the angle formed between the axis of symmetry L2 and the direction of gravity action is 0 to 3 degrees. Therefore, the deformation of the refractory metal component 20 during the carburizing process can be suppressed even better.

(Third embodiment)
In the following description of the third embodiment, only different parts from the second embodiment will be described. In the second embodiment and the third embodiment, parts that are the same or equivalent to each other are given the same reference numerals. Therefore, in the following description of the third embodiment, the components having the same reference numerals as those in the second embodiment are not described in the first embodiment and the second embodiment unless technical contradiction or special additional explanation is given. It may be incorporated as appropriate.

  Referring to FIG. 8, in the present embodiment, the laminate S has a carbon source member 50. In the present embodiment, the carbon source member 50 is provided between the refractory metal component 20 and the first clamping member 21.

  The carbon source member 50 is a felt-like or sponge-like member containing carbon. Specifically, for example, a commercially available carbon fiber felt material can be used as the carbon source member 50.

  In the present embodiment, the refractory metal part 20, the first clamping member 21, and the second clamping member 22 have a cylindrical shape having a symmetry axis L2, specifically, a cylindrical shape. Further, in the manufacturing method of the present embodiment, the laminate S is formed in a state where a felt-like or sponge-like carbon source member 50 containing carbon is sandwiched between the refractory metal component 20 and the first sandwiching member 21. To do.

  Specifically, for example, the stacked body S can be formed as follows. The carbon source member 50 is covered around the second holding member 22. Inside the refractory metal part 20, the second holding member 22 in a state in which the carbon source member 50 is covered is accommodated. Thereafter, the refractory metal component 20 is accommodated inside the first clamping member 21.

  Subsequently, the stacked body S is put into the heating furnace 30 with the axis of symmetry L2 along the direction of gravity action. Specifically, the angle formed between the symmetry axis L2 and the direction of gravity action is about 0 to 3 degrees. Subsequently, the stacked body S put in the heating furnace 30 is heated in the heating furnace 30. The heating temperature is, for example, 2000 ° C. or higher. Thereby, a carburizing process is performed.

  In the present embodiment, during the carburizing process, a felt-like or sponge-like carbon source member 50 containing carbon is interposed between the refractory metal part 20 and the first holding member 21 accommodated inside thereof. ing. For this reason, even if the difference between the inner diameter of the refractory metal component 20 and the outer diameter of the second clamping member 22 increases due to the difference in thermal expansion, the contact state between the inner surface of the refractory metal component 20 and the carbon source member 50 Is maintained well. Therefore, carburizing to the refractory metal component 20 during the carburizing process can proceed well.

  Further, the carburizing atmosphere gas in the heating furnace 30 can pass through the carbon source member 50. As a result, a carbon-containing gas that can be a carbon source is generated in the vicinity of the inner surface of the refractory metal component 20. Therefore, carburizing to the refractory metal component 20 during the carburizing process can proceed well.

(Fourth embodiment)
In the following description of the fourth embodiment, only parts different from the second embodiment will be described. Moreover, in 2nd embodiment and 4th embodiment, the same code | symbol is attached | subjected to the part which is mutually the same or equivalent. Therefore, in the following description of the fourth embodiment, the components having the same reference numerals as those in the second embodiment are not described in the first embodiment and the second embodiment unless technical contradiction or special additional explanation is given. It may be incorporated as appropriate.

  Referring to FIG. 9, in the present embodiment, the carburized component 10 includes a cylindrical portion 101, an extending portion 102, and a bent portion 103. The cylindrical portion 101 is formed in a cylindrical shape, specifically, a cylindrical shape along the symmetry axis L2. The extending portion 102 extends from the cylindrical portion 101 in the radial direction intersecting the symmetry axis L2. The “radial direction” is a direction orthogonal to the symmetry axis L2 and extending radially from the symmetry axis L2.

  In the present embodiment, the extending portion 102 extends radially outward from one end (that is, the lower end in the drawing) of the cylindrical portion 101 in the axial direction. The “axial direction” is a direction parallel to the symmetry axis L2. That is, the carburized component 10 is formed in a flanged cylindrical shape.

  The bent portion 103 is a portion where the plate material is bent in an L shape, and is provided at a connection portion between the tube portion 101 and the extended portion 102. In the present embodiment, the carburized component 10 is integrally formed without a seam. That is, the tube portion 101 and the extended portion 102 are integrally connected at the bent portion 103 without a joint.

  The carburized component 10 is formed by carburizing a refractory metal component 20 having a shape shown in FIG. Specifically, referring to FIG. 10, the refractory metal component 20 includes a cylindrical portion 201, an extending portion 202, and a bent portion 203.

  The cylindrical portion 201 is a portion corresponding to the cylindrical portion 101 in the carburized component 10 and is formed in a cylindrical shape, specifically, a cylindrical shape along the symmetry axis L2. The extended portion 202 is a portion corresponding to the extended portion 102 in the carburized component 10 and extends from the cylindrical portion 201 in the radial direction. The bent portion 203 is a portion corresponding to the bent portion 103 in the carburized component 10 and is provided at a connection portion between the cylindrical portion 201 and the extended portion 202.

  In the present embodiment, the refractory metal component 20 is integrally formed with no joint. Specifically, the refractory metal part 20 is formed into a brazed cylindrical shape by performing plastic working (that is, bending) on a cylindrical part formed of tantalum or a tantalum alloy that is a refractory metal. Has been.

  In the present embodiment, the first clamping member 21 is formed in a cylindrical shape, specifically, a cylindrical shape along the symmetry axis L2. The first clamping member 21 has an axial dimension that is shorter than the axial dimension of the cylindrical part 201 in the refractory metal part 20 by the thickness of the extending part 202.

  Similar to the refractory metal component 20, the second clamping member 22 is formed in a flanged cylindrical shape. Specifically, the second clamping member 22 has an inner cylinder part 221 and an extension part 222.

  The inner cylinder portion 221 is formed in a cylindrical shape, specifically, a cylindrical shape along the symmetry axis L2. The inner cylinder part 221 has an axial dimension that is longer than the axial dimension of the cylinder part 201 in the refractory metal part 20 by the thickness of the extending part 202. That is, in the laminated body S, the first clamping member 21 and the second clamping member 22 are arranged so that the other end (that is, the upper end in the drawing) of the cylindrical portion 201 of the refractory metal component 20 does not protrude in the axial direction. The shape and dimensions are set.

  The extending portion 222 extends radially outward from one end (that is, the lower end in the drawing) of the inner cylinder portion 221 in the axial direction. The extending portion 222 is formed so that the outer diameter (that is, the dimension in the radial direction) substantially matches the outer diameter of the extending portion 202 in the refractory metal part 20. That is, in the laminated body S, the shapes and dimensions of the first clamping member 21 and the second clamping member 22 are set so that the extended portion 202 of the refractory metal component 20 does not protrude radially outward.

  In the manufacturing method of the present embodiment, first, a brazed cylindrical refractory metal part 20 having a structure having a cylindrical portion 201, an extending portion 202, and a bent portion 203 is formed by plastic processing (that is, bending processing or the like). Form. In the laminate S, a first sandwiching member 21 and a second sandwiching member 22 having a shape and dimensions that prevent the refractory metal component 20 from protruding in the axial direction or the radial direction are prepared. Specifically, a cylindrical first clamping member 21 having an axial dimension slightly shorter than the axial dimension of the refractory metal part 20 is prepared. Also, a brazed tubular second clamping member 22 having an axial dimension slightly longer than the axial dimension of the refractory metal part 20 is prepared.

  Next, the refractory metal component 20 is sandwiched between the first sandwiching member 21 and the second sandwiching member 22, so that the laminated body of the refractory metal component 20, the first sandwiching member 21, and the second sandwiching member 22. S is formed. Specifically, the laminated body S is formed by housing the refractory metal component 20 inside the first sandwiching member 21 and housing the second sandwiching member 22 inside the refractory metal component 20.

  At this time, the cylinder part 201 and the extension part 202 in the refractory metal component 20 and the first clamping member 21 are substantially in close contact with each other. Moreover, the cylinder part 201 in the refractory metal component 20 and the inner cylinder part 221 in the second clamping member 22 are substantially in close contact with each other. Similarly, the extended portion 202 in the refractory metal component 20 and the extended portion 222 in the second clamping member 22 are substantially in close contact with each other.

  Subsequently, as shown in FIG. 10, the stacked body S is put into the heating furnace 30 with the symmetry axis L <b> 2 along the direction of gravity action. Specifically, the angle formed between the symmetry axis L2 and the direction of gravity action is about 0 to 3 degrees. Subsequently, the stacked body S put in the heating furnace 30 is heated in the heating furnace 30. The heating temperature is, for example, 2000 ° C. or higher. Thereby, a carburizing process is performed.

  By the way, residual stress is generated in the refractory metal part 20 due to plastic working. Such residual stress is particularly large at the bent portion 203. For this reason, if the high melting point metal part 20 is gas carburized without using the first clamping member 21 and the second clamping member 22, the residual stress is released along with heating, so that the high melting point during the carburization. The metal part 20 may be deformed. Then, there exists a possibility that the dimension or shape in the carburized component 10 obtained after carburizing may deviate from a desired state.

  In this respect, the manufacturing method of the present embodiment restrains the entire outer shape of the refractory metal part 20 formed into a brazed cylindrical shape by plastic working between the first clamping member 21 and the second clamping member 22. Carburizing treatment is performed. Thereby, generation | occurrence | production of a deformation | transformation of the refractory metal component 20 and the carburized component 10 resulting from a residual stress can be suppressed favorably.

(Modification)
The present invention is not limited to the above embodiment. Therefore, it can change suitably with respect to the said embodiment. Hereinafter, typical modifications will be described. In the following description of the modified example, only the parts different from the above embodiment will be described. Moreover, in the said embodiment and a modification, the same code | symbol is attached | subjected to the part which is mutually the same or equivalent. Therefore, in the following description of the modified example, regarding the components having the same reference numerals as those in the above embodiment, the description in the above embodiment can be incorporated as appropriate unless there is a technical contradiction or special additional explanation.

  The present invention is not limited to the specific configuration and manufacturing method shown in the above embodiment. For example, the refractory metal part 20 may be niobium or a niobium alloy. In addition, the present invention can be suitably applied to the manufacture of carburized refractory metal parts used for high temperature chemical crucibles and the like.

  The carburized component 10 can be formed in a state where almost the entire carburized component 10 is carburized. In other words, the entire carburized component 10 may be the carburized layer 12. In other words, the central portion 11 as a non-carburized region may be omitted.

  The shapes of the carburized component 10 and the refractory metal component 20 are not particularly limited as long as the present invention is applied satisfactorily. That is, for example, the carburized component 10 and the refractory metal component 20 can be formed in an elliptical cylindrical shape or a polygonal cylindrical shape. Alternatively, for example, the carburized component 10 and the refractory metal component 20 can be formed in a bottomed cylindrical shape.

  In FIG. 2, the stacking axis L1 may be substantially horizontal. In addition, the angle formed by the stacking axis L1 and the symmetry axis L2 and the horizontal direction or the gravitational action direction can be appropriately set as long as no deformation occurs during the carburizing process.

  2 and 4, one of the first clamping member 21 and the second clamping member 22 may be a member (for example, a ceramic member) that does not have a function as a carbon supply source.

  A carbon supply source for gas carburizing (for example, carburizing gas) may be introduced into the heating furnace 30. That is, the present invention is not limited to so-called solid carburization.

  The carburizing temperature is not limited to 2000 ° C. or higher. That is, for example, the carburizing temperature may be 1500 ° C. or higher.

  As shown in FIG. 8, when the carbon source member 50 is provided between the refractory metal part 20 and the first clamping member 21, the first clamping member 21 does not have a function as a carbon supply source. It may be a member (for example, a ceramic member).

  The carbon source member 50 can also be used in the manufacturing method shown in FIG.

  The carbon source member 50 may be provided between the refractory metal component 20 and the second clamping member 22 instead of or together with the refractory metal component 20 and the first clamping member 21.

  It goes without saying that the elements constituting the above-described embodiment are not necessarily essential except for the case where it is clearly indicated that it is essential and the case where it is considered that it is clearly essential in principle. In addition, when numerical values such as the number, numerical value, quantity, range, etc. of a component are mentioned, the specifics are specified unless explicitly stated as being essential, and clearly limited to a specific number in principle. The present invention is not limited to this number. Similarly, when the shape, direction, positional relationship, etc. of a component are mentioned, except when clearly stated as essential and in principle limited to a specific shape, direction, positional relationship, etc. The present invention is not limited to the shape, direction, positional relationship, and the like. The material constituting each part is not particularly limited unless it is specified as being particularly essential, or is clearly limited to a specific material in principle.

  The modification is not limited to the above example. Also, multiple embodiments can be combined with each other. Similarly, multiple variations can be combined with each other. Furthermore, at least one of the plurality of embodiments and at least one of the plurality of modifications may be combined with each other.

DESCRIPTION OF SYMBOLS 10 Carburized part 20 Refractory metal part 21 1st clamping member 22 2nd clamping member 30 Heating furnace 31 Mounting stand 40 Heat-resistant member L1 Loading axis L2 Symmetry axis S Laminate

Claims (13)

A method of manufacturing a carburized part (10) by carburizing a refractory metal part (20),
By sandwiching the refractory metal part between the first clamping member (21) and the second clamping member (22), both of which are rigid bodies, the first clamping member, the refractory metal part, and the second clamping Forming a laminate (S) with the member,
Carburizing while heating the laminate,
Manufacturing method of carburized parts. The first sandwiching member, the refractory metal component, and the second sandwiching member have a plate shape or a block shape,
The laminated body is obtained by arranging the first sandwiching member, the refractory metal component, and the second sandwiching member in the stacking direction,
In the state where the stacking direction is along the direction of gravity action, the carburizing treatment is performed.
The manufacturing method according to claim 1. On the laminate, the carburizing treatment is performed in a state where a heat-resistant member (40) having a density of 1.5 g / cm ³ or more is placed.
The manufacturing method according to claim 2. The first clamping member, the refractory metal part, and the second clamping member have a cylindrical shape having an axis of symmetry (L2),
The laminate is formed by housing the refractory metal part inside the first sandwiching member and housing the second sandwiching member inside the refractory metal part,
The manufacturing method according to claim 1. Carburizing treatment is performed in a state where the axis of symmetry is along the direction of gravity action.
The manufacturing method according to claim 4. The thermal expansion coefficient of the first clamping member is equal to or lower than the thermal expansion coefficient of the second clamping member.
The manufacturing method of Claim 4 or 5. When the thermal expansion coefficient of the first clamping member is C1, the thermal expansion coefficient of the second clamping member is C2,
C1 = 2.5 to 5.0 × 10 ⁻⁶ [1 / K],
C2 = 5.0 to 6.6 × 10 ⁻⁶ [1 / K].
The manufacturing method according to claim 6. The refractory metal component includes a cylindrical portion (201) formed in a cylindrical shape along the symmetry axis by plastic working, and an extending portion (a portion extending from the cylindrical portion in a direction crossing the symmetry axis). 202) and a bent portion (203) provided at a connection portion between the cylindrical portion and the extending portion,
The manufacturing method as described in any one of Claims 4-7. The first clamping member, the refractory metal part, and the second clamping member have a cylindrical shape,
The outer diameter of the refractory metal part is D0, the inner diameter is d0,
The inner diameter of the first clamping member is d1,
When the outer diameter of the second clamping member is D2,
D0 = 80 to 160 [mm], d0 = 77 to 157 [mm],
d1 = D0 + α, α = 1.5-5 [mm],
D2 = d0−β, β = 1.5-3 [mm].
The manufacturing method as described in any one of Claims 4-8. In the carburizing treatment, the refractory metal part is heated at a temperature of 2000 ° C. or higher.
The manufacturing method as described in any one of Claims 1-9. One or both of the first clamping member and the second clamping member are used as a carbon supply source.
The manufacturing method as described in any one of Claims 1-10. The laminate is formed with a felt-like or sponge-like carbon source member (50) containing carbon sandwiched between the first sandwiching member or the second sandwiching member and the refractory metal part. ,
The manufacturing method as described in any one of Claims 1-11. The refractory metal part is tantalum, a tantalum alloy, niobium, or a niobium alloy.
The manufacturing method as described in any one of Claims 1-12.

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