Manufacturing method for turbine components

Abstract

To suppress the production cost of a turbine component while removing residual powder in an internal passage.SOLUTION: Provided is a turbine component production method of executing a molded object formation step of bonding and solidifying metal powder while arranging the metal powder on a base plate to form a laminated molded object having an internal passage and an exhaust passage connected to the internal passage, and a powder removal step of removing the unnecessary metal powder left in the internal passage. The internal passage has an introduction opening that opens at an external face other than a base opposite face as an external face facing the base plate among the plural external faces of the laminated molded object. The exhaust passage has an exhaust opening that opens at an external face other than the base opposite face among the plural external faces. In the powder removal step, a gas is introduced from the introduction opening of the internal passage into the internal passage to exhaust the residual powder in the internal passage from the exhaust opening of the exhaust passage together with the gas.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing turbine components that make up a turbine.

Background Art

[0002] Many of the turbine components that make up a turbine have three-dimensional complex shapes. Therefore, in recent years, a method for manufacturing turbine components using a layered manufacturing method has been studied.

[0003] As a method for manufacturing components and the like by this layered manufacturing method, for example, there is a method disclosed in Patent Document 1 below. In this method, while arranging metal powder on a base plate, the metal powder is bonded and solidified to form a layered structure that becomes a component or the like. This layered structure has a plurality of outer surfaces and internal passages existing within the plurality of outer surfaces. The internal passage has two openings that open on a base opposing surface that faces the base plate among the plurality of outer surfaces. After the formation of the layered structure, metal powder remains in the internal passage. Therefore, in this method, after forming the layered structure on the base plate, first, an inlet hole that penetrates the base plate and communicates with one of the two openings of the internal passage, and an outlet hole that penetrates the base plate and communicates with the other of the two openings of the internal passage are formed. Then, compressed air or the like is introduced from the inlet hole of the base plate, and the metal powder in the internal passage is discharged together with the compressed air or the like from the outlet hole of the base plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The method described in Patent Document 1 above has the problem that, because holes are made in the base plate, the base plate cannot be reused, and manufacturing costs are increased.

[0006] Therefore, the present disclosure aims to provide a method for manufacturing turbine components that can remove residual powder in the internal passages while keeping manufacturing costs down. [Means for solving the problem]

[0007] A method for manufacturing a turbine component according to one embodiment of the invention for achieving the above objective is: The process involves: a molding process in which metal powder is placed on a base plate and the metal powder is bonded and solidified to form an additively manufactured object having a plurality of outer surfaces, internal passages located within the plurality of outer surfaces, and discharge passages communicating with the internal passages; a powder removal process in which residual powder, which is unwanted metal powder remaining in the internal passages, is removed; a heat treatment process in which the additively manufactured object on the base plate is heated after the powder removal process to perform heat treatment on the additively manufactured object; a plate release process in which the additively manufactured object is separated from the base plate after the heat treatment process; and a finishing process in which a turbine component is completed using the additively manufactured object separated from the base plate. The internal passages of the additively manufactured object formed in the molding process have an introduction opening that opens on an introduction opening surface, which is one of the plurality of outer surfaces, excluding the base-facing surface, which is the outer surface facing the base plate. The discharge passage of the additively manufactured object formed in the above-mentioned object formation step has a discharge opening that opens on a discharge opening surface which is at least one of the plurality of outer surfaces excluding the base-facing surface. In the powder removal step, fluid is introduced into the internal passage from the introduction opening of the internal passage, and the residual powder in the internal passage is discharged together with the fluid from the discharge opening of the discharge passage.

[0008] In this embodiment, the powder removal step S2 is performed after the molding process and before the heat treatment process, so that residual powder, which is unwanted metal powder remaining in the internal passages of the additively manufactured object, can be removed. Furthermore, in this embodiment, among the multiple outer surfaces of the additively manufactured object, an introduction opening for introducing a fluid such as gas into the internal passages during the powder removal step, and an discharge opening for discharging the residual powder together with the fluid during this powder removal step are formed on the outer surfaces excluding the base-facing surface, which is the outer surface facing the base plate. Therefore, there is no need to process the base plate when removing the powder. For this reason, in this embodiment, the base plate can be reused, and the manufacturing cost of the turbine parts can be reduced. [Effects of the Invention]

[0009] According to one aspect of this disclosure, it is possible to reduce the manufacturing cost of turbine components while removing residual powder from the internal passages. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view of a gas turbine according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view of a main part of a gas turbine according to one embodiment of the present invention. [Figure 3] This is a perspective view of a segmented ring, which is a turbine component in one embodiment of the present invention. [Figure 4] Figure 3 shows a cross-sectional view along line IV-IV. [Figure 5] This is a flowchart showing the manufacturing procedure for a turbine component according to one embodiment of the present invention. [Figure 6] This is a perspective view of an additively manufactured object according to one embodiment of the present invention. [Figure 7] This is a cross-sectional view taken along line VII-VII in Figure 6. [Figure 8] This is a view from arrow VIII in Figure 6. [Figure 9] This is an explanatory diagram illustrating the powder removal process in one embodiment of the present invention. [Figure 10]It is an explanatory diagram for explaining the opening blocking step in one embodiment according to the present invention. [Figure 11] It is an explanatory diagram for explaining the step of removing the discharge passage forming portion in one embodiment according to the present invention. [Figure 12] It is an explanatory diagram for explaining the discharge opening blocking step of blocking the first discharge opening in a modification of one embodiment according to the present invention. [Figure 13] It is an explanatory diagram for explaining the discharge opening blocking step of blocking the second discharge opening in a modification of one embodiment according to the present invention.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of a turbine component according to the present disclosure and a turbine including this turbine component will be described in detail with reference to the drawings.

[0012] 「Embodiments of the Turbine」 Embodiments of the turbine will be described with reference to FIGS. 1 to 4.

[0013] The turbine in the present embodiment is, as shown in FIG. 1, a gas turbine 1. This gas turbine 1 includes a compressor 10 that compresses outside air A to generate compressed air Acom, a combustor 20 that burns fuel F from a fuel supply source in the compressed air Acom to generate combustion gas G, and a turbine 30 that is driven by the combustion gas G.

[0014] The compressor 10 has a compressor rotor 11 that rotates about the axis Ar, a compressor casing 15 that covers the compressor rotor 11, and a plurality of stator blade rows 18. The turbine 30 has a turbine rotor 31 that rotates about the axis Ar, a turbine casing 35 that covers the turbine rotor 31, and a plurality of stator blade rows 38. Hereinafter, the direction in which the axis Ar extends is the axial direction Da, the circumferential direction centered on this axis Ar is simply the circumferential direction Dc, and the direction perpendicular to the axis Ar is the radial direction Dr. Also, one side in the axial direction Da is the upstream side Dau of the axis, and the opposite side is the downstream side Dad of the axis. Further, the side approaching the axis Ar in the radial direction Dr is the inner side Dri in the radial direction, and the opposite side is the outer side Dro in the radial direction.

[0015] The compressor 10 is arranged on the upstream side Dau of the axis with respect to the turbine 30.

[0016] The compressor rotor 11 and the turbine rotor 31 are located on the same axis Ar and are connected to each other to form a gas turbine rotor 2. For example, a rotor of a generator GEN is connected to this gas turbine rotor 2. The gas turbine 1 further includes an intermediate casing 6. This intermediate casing 6 is arranged between the compressor casing 15 and the turbine casing 35 in the axial direction Da. The compressor casing 15, the intermediate casing 6, and the turbine casing 35 are connected to each other to form a gas turbine casing 5.

[0017] As shown in FIGS. 1 and 2, the compressor rotor 11 has a rotor shaft 12 that extends in the axial direction Da about the axis Ar, and a plurality of moving blade rows 13 attached to this rotor shaft 12. The plurality of moving blade rows 13 are arranged in the axial direction Da. Each moving blade row 13 is composed of a plurality of moving blades arranged in the circumferential direction Dc. On the downstream side Dad of each of the plurality of moving blade rows 13 in the axial direction, one of the plurality of stator blade rows 18 is arranged. Each stator blade row 18 is provided inside the compressor casing 15. Each stator blade row 18 is composed of a plurality of stator blades arranged in the circumferential direction Dc.

[0018] The turbine rotor 31 has a rotor shaft 32 extending in the axial direction Da with respect to the axis Ar, and a plurality of rotor blade rows 33 attached to the rotor shaft 32. The plurality of rotor blade rows 33 are arranged in the axial direction Da. Each rotor blade row 33 is composed of a plurality of rotor blades arranged in the circumferential direction Dc. One of a plurality of stator blade rows 38 is positioned on the upstream side Dau of each rotor blade row 33 along its axis. Each stator blade row 38 is located inside the turbine casing 35. Each stator blade row 38 is composed of a plurality of stator blades arranged in the circumferential direction Dc.

[0019] The annular space between the outer circumference of the rotor shaft 32 and the inner circumference of the turbine casing 35, where the rotor blade row 33 and stator blade row 38 are arranged in the axial direction Da, forms a combustion gas passage 39 through which the combustion gas G from the combustor 20 flows. This combustion gas passage 39 is annular with respect to the axis Ar and is elongated in the axial direction Da.

[0020] As shown in Figure 2, the turbine casing 35 has a turbine casing body 36 and a plurality of segmented rings 40. The segmented rings 40 are located radially outward Dro of the rotor blade row 33 and face the rotor blade row 33 in the radial direction Dr. These segmented rings 40 define a portion of the radially outward Dro edge of the combustion gas flow path 39 at the axial direction Da where the rotor blade row 33 is located. The turbine casing body 36 is cylindrical with its axis Ar as the center so as to surround the outer circumference of the turbine rotor 31. A plurality of stator blade rows 38 and a plurality of segmented rings 40 are attached to the inner circumference portion of this turbine casing body 36.

[0021] The combustor 20 is attached to the intermediate casing 6. As shown in Figure 2, the combustor 20 has a tailpipe (or combustion chamber) 22 in which the fuel F burns, and a plurality of burners 21 that inject fuel into the tailpipe 22.

[0022] As shown in Figures 3 and 4, the aforementioned segmented ring 40 has a base material 41 and a heat-shielding coating layer 49 formed on a part of the surface of the base material 41. The base material 41 is made of, for example, a nickel-based alloy. The heat-shielding coating layer 49 has a bond coat layer formed on the surface of the base material 41 and a top coat layer formed on the surface of the bond coat layer. The bond coat layer is made of, for example, a metal such as CoNiCrAlY. The top coat layer is made of, for example, a ZrO2-based ceramic.

[0023] The base material 41 has a plate-shaped segmented ring body 42 that extends in the circumferential direction Dc and the axial direction Da, a circumferential wall 47 that extends radially outward Dro from the periphery of the segmented ring body 42, and a plurality of hooks 48 formed on a part of the circumferential wall 47. The segmented ring body 42 has a front end face 43f, a rear end face 43b, a pair of side end faces 43s, a gas path side face 45p, and an anti-gas path side face 45a. The front end face 43f faces axially upstream Dau. The rear end face 43b is back-to-back with respect to the front end face 43f and faces axially downstream Dad. The pair of side end faces 43s face circumferential Dc and are back-to-back with respect to each other. The gas path side face 45p faces radially inward Dri. The anti-gas path side face 45a faces radially outward Dro. The circumferential wall 47 has a front wall 47f, a rear wall 47b, and a pair of side walls 47s. The front wall 47f is formed to follow the front end surface 43f of the divided ring body 42. The rear wall 47b is formed to follow the rear end surface 43b of the divided ring body 42. The front wall 47f and the rear wall 47b are spaced apart from each other and face each other in the axial direction Da. One of the pair of side walls 47s is formed to follow one of the pair of side end surfaces 43s of the divided ring body 42. The other of the pair of side walls 47s is formed to follow the other of the pair of side end surfaces 43s of the divided ring body 42. The pair of side walls 47s are spaced apart from each other and face each other in the circumferential direction Dc. Of the multiple hooks 48, some are formed on the radially outer Dro of the front wall 47f, and others are formed on the radially outer Dro of the rear wall 47b. Each hook 48 has a portion that extends radially outward to the Dro and a portion that extends axially in Da from the end of the radially outward Dro of this portion. These hooks 48 are responsible for attaching the divided ring 40 to the turbine casing body 36.

[0024] The segmented ring body 42 further has a plurality of cooling air passages 46. Each cooling air passage 46 has an introduction passage 46a and a main passage 46b. The introduction passage 46a extends from the boundary between the anti-gas path side surface 45a and the front wall 47f of the segmented ring body 42, gradually moving towards the radially inward Dri as it moves towards the axial upstream side Dau. This introduction passage 46a has an air inlet 46i that opens at the boundary between the anti-gas path side surface 45a and the front wall 47f of the segmented ring body 42. The main passage 46b communicates with the introduction passage 46a at the axial upstream side Dau and the radially inward end Dri. This main passage 46b extends from the point of communication with the introduction passage 46a toward the axial downstream side Dad. The main passage 46b has an air outlet 46o that opens at the rear end surface 43b of the segmented ring body 42. In the surface defining the main passage 46b, the portion on the side of the gas path lateral surface 45p is formed to repeat irregularities in the direction in which the main passage extends. In other words, a turbulator 57 is formed on the surface defining the main passage 46b.

[0025] The heat-shielding coating layer 49 is formed on the gas path side surface 45p, the front end surface 43f, the rear end surface 43b, and the pair of side end surfaces 43s of the divided ring body 42.

[0026] All of the components that make up the gas turbine 1 described above are turbine components. Among the turbine components, those that come into contact with high-temperature combustion gases are turbine high-temperature components. Turbine high-temperature components include the components that make up the combustor 20, the stator blades of the turbine 30, the rotor blades of the turbine 30, and the segmented ring 40.

[0027] "Embodiment of a manufacturing method for turbine components" The manufacturing method for the divided ring 40, which is one of the turbine components, will be described below with reference to Figures 5 to 11.

[0028] In the manufacturing of the segmented ring 40, as shown in the flowchart of Figure 5, first, an additively manufactured object is formed (object formation process S1). In this embodiment, this additively manufactured object is formed by powder bed fusion (PBF) method. In this PBF method, as shown in Figure 6, metal powder to form the additively manufactured object 50 is placed on a base plate P, and high-density energy is irradiated onto a predetermined area of ​​the metal powder layer on the base plate P to melt the metal powder in this area. Then, the molten metal in this area is rapidly cooled and solidified to form a metal solidification layer of a predetermined shape. In the PBF method, a metal solidification layer of a predetermined shape is repeatedly formed on the metal solidification layer using the above method to form an additively manufactured object 50 with a predetermined three-dimensional shape.

[0029] The PBF method described above includes the SLM (Selective Laser Melting) method, which melts metal powder with laser light and then bonds and solidifies the metal powder, and the EBM (Electron Beam Melting) method, which melts metal powder with an electron beam and then bonds and solidifies the metal powder. In this embodiment, the SLM method is adopted. However, the EBM method may also be adopted in this embodiment.

[0030] This additively manufactured object 50 becomes the base material 41 of the divided ring 40 described earlier. Therefore, in this embodiment, the metal powder used to form the additively manufactured object 50 is nickel-based alloy powder. As shown in Figures 6 to 8, the additively manufactured object 50 has a main body portion 52 which becomes the divided ring body 42, a peripheral wall portion 67 which becomes the peripheral wall 47 of the divided ring 40, and a hook portion 68 which becomes a plurality of hooks 48 of the divided ring 40. The main body portion 52, like the divided ring body 42, has a front end surface 53f, a rear end surface 53b, a pair of side end surfaces 53s, a gas pass side surface 55p, and an anti-gas pass side surface 55a. The front end surface 53f and the rear end surface 53b are back to back with each other. The pair of side end surfaces 53s are back to back with each other. The gas pass side surface 55p and the anti-gas pass side surface 55a are back to back with each other. The gas path side surface 55p and the anti-gas path side surface 55a extend in a direction having a component perpendicular to the direction in which the front end surface 53f extends, the direction in which the rear end surface 53b extends, and the direction in which the pair of side end surfaces 53s extend. Each of the pair of side end surfaces 53s connects the front end surface 53f and the rear end surface 53b, and also connects the gas path side surface 55p and the anti-gas path side surface 55a.

[0031] The main body 52 of the additively fabricated object 50 further has a plurality of internal passages 56 and a plurality of discharge passages 66. The internal passages 56 extend in a direction having a component perpendicular to the base plate P, in other words, in the vertical direction. These internal passages 56 form the cooling air passages 46 of the divided ring 40. For this reason, the internal passages 56 have a sub-internal passage 56a which becomes the introduction passage 46a of the cooling air passage 46, and a main internal passage 56b which becomes the main passage 46b of the cooling air passage 46. The sub-internal passage 56a extends from the boundary between the anti-gas pass side surface 55a of the main body 52 and the front wall portion 67f of the peripheral wall portion 67, gradually moving towards the gas pass side surface 55p as it approaches the front end surface 53f. This sub-internal passage 56a has an anti-gas pass side opening 56ao that opens at the boundary between the anti-gas pass side surface 55a of the main body 52 and the front wall portion 67f. This anti-gas pass side opening 56ao forms the air inlet 46i of the cooling air passage 46. The main internal passage 56b extends from the front end surface 53f to the rear end surface 53b of the additively manufactured object 50. This main internal passage 56b has a front opening 56bf that opens at the front end surface 53f of the additively manufactured object 50 and a rear opening 56bb that opens at the rear end surface 53b of the additively manufactured object 50. The main internal passage 56b communicates with the sub-internal passage 56a at the end on the front end surface 53f side of the sub-internal passage 56a and the end on the gas pass side surface 55p side. In the surface that defines the main internal passage 56b, the portion on the gas pass side surface 55p side is formed to repeat irregularities in the direction in which the main internal passage 56b extends. That is, a turbulator 57 is formed on the surface that defines the main internal passage 56b.

[0032] The rear end surface 53b of the main body portion 52 forms a base-facing surface 83 that faces the base plate P. The front end surface 53f of the main body portion 52 forms a base-opposite surface 84 and also forms an introduction opening surface 85 in which the front opening 56bf of the main internal passage 56b is formed. The front opening 56bf of the main internal passage 56b forms an introduction opening 56io.

[0033] Of the multiple discharge passages 66, some of them constitute the first discharge passage 66a, and the other discharge passage 66 constitutes the second discharge passage 66b. As shown in Figures 6 to 8, both the first discharge passage 66a and the second discharge passage 66b communicate with the internal passage 56 at the end closest to the base plate and extend along the base plate P. Here, the end closest to the base plate in the internal passage 56 is the portion from the end closest to the base plate P in the internal passage 56 to a distance of, for example, 1 / 10 of the total length of the internal passage 56.

[0034] Each of the multiple first discharge passages 66a communicates with one of the multiple internal passages 56 at the end of the internal passage 56 closest to the base plate P. This first discharge passage 66a is a groove that is recessed upward from the base-facing surface 83 and extends from the point of communication with the internal passage 56 to the gas path side surface 55p and the rear anti-gas path side surface 55ab, which is the surface of the rear wall portion 67b that is opposite to the gas path. In other words, the first discharge passage 66a is a groove that is recessed upward from the base-facing surface 83 and extends from the gas path side surface 55p to the rear anti-gas path side surface 55ab of the rear wall portion 67b, communicating with one of the internal passages 56 along the way. This first discharge passage 66a has a first discharge opening 66ao as a discharge opening 66o, which is open at the gas path side surface 55p and the rear anti-gas path side surface 55ab. Therefore, both the gas path side surface 55p and the rear opposite gas path side surface 55ab form the first discharge opening surface 86a, which is the discharge opening surface 86.

[0035] The second discharge passage 66b is located at the end of the internal passage 56 closer to the base plate, and is located on the front end surface 53f (base-facing surface 83) side of the communication point between the first discharge passage 66a and the internal passage 56, and communicates with all of the internal passages 56. This second discharge passage 66b extends from one of the pair of side end surfaces 53s to the other side end surface 53s, and communicates with all of the internal passages 56 along the way. Therefore, this second discharge passage 66b communicates with each of the multiple first discharge passages 66a. Furthermore, this second discharge passage 66b extends in a different direction from the first discharge passages 66a. This second discharge passage 66b has a discharge opening 66o, which is a second discharge opening 66bo that opens on each of the pair of side end surfaces 53s of the main body 52. ​​Therefore, each of the pair of side end surfaces 53s of the main body 52 forms a second discharge opening surface 86b as a discharge opening surface 86.

[0036] When forming an additively fabricated object 50 having an internal passage 56 using the PBF method, metal powder sprayed during the process of forming multiple metal solidification layers above the first metal solidification layer reaches the internal passage formation area in the first metal solidification layer, and this metal powder remains in this internal passage formation area. In particular, as in this embodiment, a turbulator 57 is formed on the surface that defines the internal passage 56, and because this surface has irregularities, metal powder tends to accumulate in the recessed areas. This metal powder is unwanted metal powder. Therefore, in this embodiment, when the fabrication process S1 is completed, a powder removal process S2 is performed to remove the residual powder, which is unwanted metal powder remaining in the internal passage 56.

[0037] In the powder removal process S2, as shown in Figure 9, fluid is introduced into the internal passage 56 from the introduction opening 56io, which is the front opening 56bf of the internal passage 56, and the residual powder in the internal passage 56 is discharged together with the fluid from the two first discharge openings 66ao of the first discharge passage 66a and the two second discharge openings 66bo of the second discharge passage 66b. Here, the fluid introduced to discharge the residual powder may be a gas such as air or nitrogen, or a liquid such as water. Methods for introducing and discharging the fluid include injecting the gas or liquid into the internal passage in the air, injecting the gas or liquid into the internal passage while the additively manufactured object is immersed in a liquid, or sucking the fluid introduced from the internal passage through the discharge passage. In addition to introducing the fluid from the internal passage, the fluid may also be introduced from the discharge passage.

[0038] Once the powder removal process S2 is completed, the front opening 56bf of the internal passage 56 is closed (opening closing process S3), as shown in Figure 10. In this opening closing process S3, the introduction opening 56io, which is the front opening 56bf, is closed with a lid 91 made of a nickel-based alloy, which is the same metal as the metal used to form the additively manufactured object 50, and this lid 91 is welded to the additively manufactured object 50.

[0039] Internal stress may occur in the additively manufactured object 50 on the base plate P. If the additively manufactured object 50 is separated from the base plate P while internal stress is present, the additively manufactured object 50 may deform. Furthermore, for parts exposed to high-temperature combustion gases, such as the turbine components in this embodiment, a long high-temperature creep life is required. Therefore, in this embodiment, after the powder removal step S2, the additively manufactured object 50 on the base plate P is heated to reduce the internal stress in the additively manufactured object 50 and to extend the high-temperature creep life, thereby subjecting the additively manufactured object 50 to heat treatment (heat treatment step S4).

[0040] In this heat treatment step S4, for example, the additively manufactured object 50 is heated to a temperature of around 1000°C for several hours. The heat treatment time and heating temperature are set appropriately according to the amount of metal elements that make up the additively manufactured object 50. In this heat treatment step S4, the additively manufactured object 50 is heated to a temperature of around 1000°C, so if any unwanted metal powder remains in the internal passage 56 of the additively manufactured object 50, this metal powder may melt and adhere to the inner surface of the internal passage 56. For this reason, it is necessary to perform the heat treatment step S4 after the opening sealing step S3.

[0041] Once the heat treatment process S4 is complete, the additively manufactured object 50 is separated from the base plate P (plate separation process S5).

[0042] Once the plate separation process S5 is complete, various processes are applied to the additively fabricated object 50 that has been separated from the base plate P to complete the segmented ring 40 as a turbine component (finishing process S6).

[0043] The various processes performed in this finishing process S6 differ depending on the type of turbine component, but in this embodiment, this finishing process S6 includes machining, heat shield coating layer 49 formation, and hole cleaning. In other words, this finishing process S6 performs machining S7, heat shield coating layer formation S8, and hole cleaning S9.

[0044] In machining process S7, the additively manufactured object 50 is machined to finish its outer surface. This machining process completes the base material 41 of the divided ring 40. This machining process also includes an exhaust passage formation part removal process S7a, which removes the portion of the additively manufactured object 50 that includes the base-facing surface 83 and the first and second exhaust passages 66a and 66b. As a result of this exhaust passage formation part removal process S7a, as shown in Figure 11, the rear end surface 43b of the base material 41 of the divided ring 40 is completed, and the air outlet 46o of the cooling air passage 46 that opens at the rear end surface 43b of the base material 41 is completed.

[0045] In the heat-shielding coating layer formation process S8, a heat-shielding coating layer 49 is formed on a portion of the surface of the base material 41 of the divided ring 40 completed in the machining process S7. Specifically, as shown in Figures 3 and 4, the heat-shielding coating layer 49 is formed on the gas path side surface 45p, the front end surface 43f, the rear end surface 43b, and the pair of side end surfaces 43s of the divided ring body 42, which is a portion of the base material 41. In forming this heat-shielding coating layer 49, first, a metal powder such as CoNiCrAlY is sprayed onto the surface of the base material 41 to form a bond coat layer on the surface of the base material 41. Next, a top coat layer is formed on the bond coat layer by spraying a ceramic powder such as ZrO2 onto the bond coat layer.

[0046] As described above, in the heat-shielding coating layer formation step S8, metal powder and ceramic powder are used, so these powders enter the cooling air passage 46 from the air outlet 46o of the cooling air passage 46. Therefore, in this embodiment, after the heat-shielding coating layer formation step S8, a passage cleaning step S9 is performed to remove the powder that has entered the cooling air passage 46.

[0047] This completes the segmented ring 40 as a turbine component. If necessary, an accessory attachment step may be added after the machining step S7 to attach the accessories to the base material 41.

[0048] As described above, in this embodiment, the powder removal step S2 is performed after the molded object formation step S1 and before the heat treatment step S4, so residual powder, which is unwanted metal powder remaining in the internal passage 56 of the additively molded object 50, can be removed. Furthermore, in this embodiment, multiple discharge passages 66 communicating with the internal passage 56 are formed, so residual powder in the internal passage 56 can be efficiently discharged. Moreover, in this embodiment, the first discharge passage 66a and the second discharge passage 66b extend in different directions and communicate with each other, so from this viewpoint as well, residual powder in the internal passage 56 can be efficiently discharged.

[0049] Furthermore, in this embodiment, among the multiple outer surfaces of the additively fabricated object 50, an introduction opening 56io for introducing fluid into the internal passage 56 in the powder removal process S2 and an discharge opening 66o for discharging residual powder together with the fluid in the powder removal process S2 are formed on the outer surfaces excluding the base-facing surface 83, which is the outer surface facing the base plate P. Therefore, there is no need to process the base plate P when removing powder. For this reason, in this embodiment, the base plate P can be reused, and the manufacturing cost of the turbine components can be reduced.

[0050] Furthermore, in this embodiment, since the discharge passage formation section removal step S7a is performed, it is possible to manufacture turbine components without the discharge passage 66.

[0051] "Variations" In all of the above embodiments, the discharge passage 66 has two openings. However, the discharge passage 66 may have only one opening.

[0052] The above embodiment has a first discharge passage 66a and a second discharge passage 66b as the discharge passage 66. However, it is also possible to have only one of the discharge passages 66, the first discharge passage 66a and the second discharge passage 66b.

[0053] In the above embodiment, the main internal passage 56b formed in the molded object formation process S1 has a front opening 56bf that opens at the front end surface 53f, which is the base opposite surface 84. However, the main internal passage 56b formed in the molded object formation process S1 does not need to have a front opening 56bf. In this case, the anti-gas path side opening 56ao of the sub-internal passage 56a, which is in communication with the main internal passage 56b, is used as an introduction opening, and in the powder removal process S2, gas is introduced into the internal passage 56 from this introduction opening. Therefore, in this case, the anti-gas path side opening 56ao of the sub-internal passage 56a not only forms the air inlet 46i of the cooling air passage 46, but also serves as an introduction opening.

[0054] In the above embodiment, in the finishing step S6, a discharge passage forming part removal step S7a is performed to remove the portion of the additively manufactured object 50 that includes the base-facing surface 83 and the first discharge passage 66a and the second discharge passage 66b. However, the discharge passage forming part removal step S7a may be omitted, and the first discharge passage 66a and the second discharge passage 66b may be left in the finished divided ring 40. In this case, after the powder removal step S2, a discharge opening closing step S3a (see Figure 5) may be performed to close the first discharge opening 66ao of the first discharge passage 66a and the second discharge opening 66bo of the second discharge passage 66b. In this discharge opening closing step S3a, as shown in Figure 12, the first discharge opening 66ao is closed with a lid 92 made of a nickel-based alloy, which is the same metal as the metal forming the additively manufactured object 50, and this lid 92 is welded to the additively manufactured object 50. Furthermore, as shown in Figure 13, the second discharge opening 66bo is sealed with a lid 93 made of a nickel-based alloy, which is the same metal as the metal forming the additively manufactured object 50, and this lid 93 is welded to the additively manufactured object 50. In this case, both the first discharge opening 66ao and the second discharge opening 66bo are sealed, but either one of the openings, for example, only the second discharge opening 66bo, may be sealed.

[0055] Furthermore, although the discharge opening sealing process S3a and the aforementioned opening sealing process S3 are performed after the powder removal process S2, they may also be performed after the heat treatment process S4 or the plate separation process S5. For example, the discharge opening sealing process S3a and the aforementioned opening sealing process S3 may be performed as one of the processes in the finishing process S6. However, if welding is performed in the discharge opening sealing process S3a and the opening sealing process S3, it is preferable to perform them before the heat treatment process S4.

[0056] The turbine component in the above embodiment is the divided ring 40 of the gas turbine 1. However, other high-temperature components of the gas turbine 1 may be manufactured by the method described above, as long as they have an internal passage 56. Such other high-temperature components of the gas turbine include, as mentioned above, combustor components, turbine stator blades, turbine rotor blades, etc. Furthermore, the turbine component is not limited to a component of the gas turbine 1; it may also be a component of a steam turbine, for example, as long as it has an internal passage.

[0057] This disclosure is not limited to the embodiments and modifications described above. Various additions, modifications, substitutions, partial deletions, etc., are possible without departing from the conceptual idea and spirit of the invention derived from the claims and their equivalents.

[0058] "Addendum" The manufacturing methods for turbine components in the above embodiments and modifications can be understood, for example, as follows.

[0059] (1) The method for manufacturing turbine components in the first embodiment is: The process involves: a molding process S1 in which metal powder is placed on a base plate P and the metal powder is bonded and solidified to form an additively manufactured object 50 having a plurality of outer surfaces, internal passages 56 located within the plurality of outer surfaces, and a discharge passage 66 communicating with the internal passages 56; a powder removal process S2 in which residual powder, which is unwanted metal powder remaining in the internal passages 56, is removed; a heat treatment process S4 in which the additively manufactured object 50 on the base plate P is heated after the powder removal process S2 to perform heat treatment on the additively manufactured object 50; a plate release process S5 in which the additively manufactured object 50 is separated from the base plate P after the heat treatment process S4; and a finishing process S6 in which a turbine component is completed using the additively manufactured object 50 that has been separated from the base plate P. The internal passage 56 of the additively manufactured object 50 formed in the manufacturing process S1 has an introduction opening 56io that opens on an introduction opening surface 85, which is one of the multiple outer surfaces excluding the base-facing surface 83, which is the outer surface facing the base plate P. The discharge passage 66 of the additively manufactured object 50 formed in the manufacturing process S1 has a discharge opening 66o that opens on a discharge opening surface 86, which is at least one of the multiple outer surfaces excluding the base-facing surface 83. In the powder removal process S2, fluid is introduced into the internal passage 56 from the introduction opening 56io of the internal passage 56, and the residual powder in the internal passage 56 is discharged together with the fluid from the discharge opening 66o of the discharge passage 66.

[0060] In this embodiment, the powder removal process S2 is performed after the molded object formation process S1 and before the heat treatment process S4, so that residual powder, which is unwanted metal powder remaining in the internal passage 56 of the additively manufactured object 50, can be removed. Furthermore, in this embodiment, among the multiple outer surfaces of the additively manufactured object 50, an introduction opening 56io for introducing a fluid such as gas into the internal passage 56 in the powder removal process S2, and an discharge opening 66o for discharging the residual powder together with the fluid in the powder removal process S2 are formed on the outer surfaces excluding the base-facing surface 83, which is the outer surface facing the base plate P. Therefore, there is no need to process the base plate P when removing the powder. For this reason, in this embodiment, the base plate P can be reused, and the manufacturing cost of the turbine parts can be reduced.

[0061] (2) The method for manufacturing turbine components in the second embodiment is: In the first embodiment of the method for manufacturing a turbine component, the discharge passage 66 has discharge openings 66o that open on each of the two outer surfaces of the plurality of outer surfaces, excluding the base-facing surface 83, and both of the two outer surfaces constitute the discharge opening surface 86.

[0062] In this embodiment, since the discharge passage 66 has two discharge openings 66o, residual powder in the internal passage 56 can be efficiently discharged to the outside of the internal passage 56.

[0063] (3) The method for manufacturing turbine components in the third embodiment is: In the manufacturing method of the turbine component according to the first or second embodiment, in the molding step S1, a plurality of discharge passages 66 that communicate with the internal passage 56 are formed.

[0064] In this embodiment, since multiple discharge passages 66 communicating with the internal passage 56 are formed, residual powder in the internal passage 56 can be efficiently discharged to the outside of the internal passage 56.

[0065] (4) The method for manufacturing turbine components in the fourth embodiment is: In the manufacturing method of the turbine component according to the third embodiment, of the plurality of discharge passages 66, the first discharge passage 66a and the second discharge passage 66b extend in directions that intersect each other and are in communication with each other.

[0066] This configuration allows for more efficient discharge of residual powder from the internal passage 56 to the outside of the internal passage 56 compared to the case where the first discharge passage 66a and the second discharge passage 66b extend in the same direction.

[0067] (5) The method for manufacturing turbine components in the fifth embodiment is: In the method for manufacturing a turbine component according to any one of the first to fourth embodiments, at least a portion of the surface that defines the internal passage 56 is formed such that the irregularities repeat in the direction in which the internal passage 56 extends.

[0068] If the surface that defines the internal passage 56 has irregularities, residual powder tends to accumulate in these depressions. For this reason, if the surface that defines the internal passage 56 has irregularities, it is preferable to always perform the powder removal step S2, as in this embodiment.

[0069] (6) The method for manufacturing a turbine component in the sixth embodiment is: In the method for manufacturing a turbine component according to any one of the first to fifth embodiments described above, the internal passage 56 includes a main internal passage 56b having an introduction opening 56io that opens on a base opposite surface 84 which is back-to-back with the base facing surface 83, and a sub-internal passage 56a which opens on an outer surface among the plurality of outer surfaces excluding the base facing surface 83 and the base opposite surface 84, and communicates with the main internal passage 56b. After any one of the steps of the powder removal step S2, the heat treatment step S4, and the plate removal step S5, an opening closing step S3 is performed to close the introduction opening 56io that opens on the base opposite surface 84 of the main internal passage 56b.

[0070] In this embodiment, the introduction opening 56io is closed after the opening closing process S3. Therefore, in this embodiment, it is possible to manufacture a turbine component that does not have an introduction opening 56io on the base opposite surface 84.

[0071] (7) The method for manufacturing a turbine component in the seventh embodiment is: In the method for manufacturing a turbine component according to any one of the first to sixth embodiments described above, the internal passage 56 extends in a direction having a component perpendicular to the base plate P. The discharge passage 66 extends in a direction having a component parallel to the base plate P.

[0072] (8) The method for manufacturing turbine components in the eighth embodiment is: In the seventh embodiment of the method for manufacturing turbine components, the discharge passage 66 communicates with the internal passage 56 at an end near the base plate within the internal passage 56 and extends along the base plate P.

[0073] (9) The method for manufacturing turbine components in the ninth embodiment is: In the manufacturing method of the turbine component according to the eighth embodiment, the discharge passage 66 is a groove that is recessed upward from the base-facing surface 83 and extends from the communication position with the internal passage 56 to the discharge opening surface 86.

[0074] (10) The method for manufacturing a turbine component in the tenth embodiment is: In the manufacturing method of the turbine component according to the eighth embodiment, the discharge passage 66 is located in the additively manufactured object 50 in a portion closer to the base plate, and is located above the base-facing surface 83, extending from the point of communication with the internal passage 56 to the discharge opening surface 86.

[0075] (11) The method for manufacturing a turbine component in the eleventh aspect is: In the method for manufacturing turbine components according to the eighth embodiment, the discharge passage 66 has a first discharge passage 66a and a second discharge passage 66b. The first discharge passage 66a is a groove that communicates with the internal passage 56 at the end of the internal passage 56 on the base plate P side, is recessed upward from the base facing surface 83, and extends from the communication position with the internal passage 56 to the first discharge opening surface 86a, which serves as the discharge opening surface 86. The second discharge passage 66b is a portion of the internal passage 56 closer to the base plate P and communicates with the internal passage 56 at a position further upward from the base plate P than the first discharge passage 66a, and extends from the communication position with the internal passage 56 to the second discharge opening surface 86b, which serves as the discharge opening surface 86. The second discharge opening surface 86b is one of the plurality of outer surfaces, excluding the base facing surface 83 and the first discharge opening surface 86a. The first discharge opening surface 86a and the second discharge opening surface 86b are both outer surfaces that are connected to the edge of the base-facing surface 83 among a plurality of outer surfaces.

[0076] In this embodiment, since multiple discharge passages 66 communicating with the internal passage 56 are formed, residual powder in the internal passage 56 can be efficiently discharged to the outside of the internal passage 56. Moreover, in this embodiment, the first discharge passage 66a and the second discharge passage 66b extend in different directions and communicate with each other, so from this viewpoint as well, residual powder in the internal passage 56 can be efficiently discharged to the outside of the internal passage 56.

[0077] (12) The method for manufacturing a turbine component in the twelfth aspect is: In the method for manufacturing a turbine component according to any one of the eighth to eleventh embodiments, the finishing step S6 includes a discharge passage forming portion removal step S7a in which the portion of the additively manufactured object 50 including the base facing surface 83 and the discharge passage 66 is removed.

[0078] In this embodiment, it is possible to manufacture turbine components without an exhaust passage 66.

[0079] (13) The method for manufacturing a turbine component in the thirteenth aspect is: In the method for manufacturing a turbine component according to any one of the first to eleven embodiments described above, after any one of the steps of the powder removal step S2, the heat treatment step S4, and the plate removal step S5, an discharge opening closing step S3a is performed to close the discharge opening 66o of the discharge passage 66.

[0080] In this embodiment, even if the discharge passage 66 is retained, it is possible to manufacture a turbine component in which the discharge passage 66 does not function as a discharge passage 66.

[0081] (14) The method for manufacturing a turbine component in the fourteenth aspect is: In the method for manufacturing a turbine component according to any one of the first to thirteen embodiments, the finishing step S6 includes a heat-shielding coating layer forming step S8 in which a heat-shielding coating layer 49 is formed on at least a portion of the multiple outer surfaces of the additively manufactured product 50. [Explanation of symbols]

[0082] 1: Gas turbine 2: Gas turbine rotor 5: Gas turbine casing 6: Intermediate casing 10: Compressor 11: Compressor rotor 12: Rotor shaft 13: Moving blade row 15: Compressor casing 18: Static Wing Arrow 20: Combustor 21: Burner 22: Tail tube (or combustion tube) 30: Turbine 31: Turbine Rotor 32: Rotor shaft 33: Moving blade row 35: Turbine casing 36: Turbine casing body 38: Static Wing Arrow 39: Combustion gas flow path 40: Split ring 41: Base material 42: Split ring body 43f: Front end surface 43b: Rear end surface 43s: Side end surface 45p: Gas pass side 45a: Side view of the anti-gas path 46: Cooling air passage 46i: Air Inlet 46o: Air outlet 46a: Introduction passage 46b: Main passage 47: Surrounding wall 47f: Front wall 47b: Back wall 47s: side wall 48: Hook 49: Heat-shielding coating layer 50: Additive-formed objects 52: Main body 53f: Front end surface 53b: Rear end surface 53s: Side end face 55p: Gas pass side 55a: Side view of the anti-gas path 55ab: Rear anti-gas path side 56: Internal passage 56a: Secondary internal passage 56ao: Opening on the anti-gas path side 56b: Main internal passage 56bf: front opening 56io: Introduction opening 56bb: Rear opening 57: Turbulator 66: Discharge passage 66o: Discharge opening 66a: First discharge passage 66ao: First discharge opening 66b:Second discharge passage 66bo:Second discharge opening 67: Peripheral wall part 67f: Front wall 68: Hook part 83: Base opposing surface 84: Opposite side of the base 85: Introduction opening surface 86:Discharge opening surface 86a: First discharge opening surface 86b: Second discharge opening surface 91,92,93: Lid A: Outside air Acom: Compressed air G: Combustion gas F:Fuel P: Base plate Ar: Axis line Da: Axial direction Dau: Axis upstream side Dad: Downstream side of the axis Dc: Circumferential direction Dr: Radial direction Dri: Radial inner side Dro: Radial outward

Claims

1. A process for forming a molded object, comprising: arranging metal powder on a base plate and bonding and solidifying the metal powder to form a laminated object having a plurality of outer surfaces, internal passages located within the plurality of outer surfaces, and discharge passages communicating with the internal passages; A powder removal step to remove residual powder, which is unwanted metal powder remaining in the internal passage, After the powder removal step, a heat treatment step is performed in which the additively manufactured object on the base plate is heated to perform heat treatment on the additively manufactured object. After the heat treatment step, a plate removal step is performed to separate the additively manufactured object from the base plate, A finishing process in which a turbine component is completed using the additively manufactured object separated from the base plate, Execute, The internal passage of the additively manufactured object formed in the aforementioned manufacturing process has an introduction opening that opens on an introduction opening surface, which is one of the multiple outer surfaces, excluding the base-facing surface which is the outer surface facing the base plate. The discharge passage of the additively manufactured object formed in the aforementioned manufacturing process has a discharge opening that opens on a discharge opening surface which is at least one of the plurality of outer surfaces excluding the base-facing surface, In the powder removal step, fluid is introduced into the internal passage from the introduction opening of the internal passage, and the residual powder in the internal passage is discharged together with the fluid from the discharge opening of the discharge passage. Manufacturing method for turbine components.

2. In the method for manufacturing a turbine component according to claim 1, The discharge passage has discharge openings that open on each of the two outer surfaces of the plurality of outer surfaces, excluding the base-facing surface, and both of the two outer surfaces form the discharge opening surfaces. Manufacturing method for turbine components.

3. In the method for manufacturing a turbine component according to claim 1, In the molding process, a plurality of discharge passages communicating with the internal passage are formed. Manufacturing method for turbine components.

4. In the method for manufacturing a turbine component according to claim 3, Of the multiple discharge passages, the first discharge passage and the second discharge passage extend in different directions from each other, but are in communication with each other. Manufacturing method for turbine components.

5. In the method for manufacturing a turbine component according to any one of claims 1 to 4, At least a portion of the surface that defines the internal passage is formed such that the irregularities repeat in the direction in which the internal passage extends. Manufacturing method for turbine components.

6. In the method for manufacturing a turbine component according to any one of claims 1 to 4, The internal passage comprises a main internal passage having an introduction opening that opens on the base opposite to the base facing surface, which is back-to-back with the base facing surface, and a secondary internal passage that opens on one of the multiple outer surfaces, excluding the base facing surface and the base opposite surface, and communicates with the main internal passage. After any one of the steps of the powder removal step, the heat treatment step, and the plate removal step, an opening closing step is performed to close the introduction opening that is open on the base opposite side of the main internal passage. Manufacturing method for turbine components.

7. In the method for manufacturing a turbine component according to any one of claims 1 to 4, The internal passage extends in a direction having a component perpendicular to the base plate, The discharge passage extends in a direction having a component parallel to the base plate. Manufacturing method for turbine components.

8. In the method for manufacturing a turbine component according to claim 7, The discharge passage communicates with the internal passage at its end near the base plate and extends along the base plate. Manufacturing method for turbine components.

9. In the method for manufacturing a turbine component according to claim 8, The discharge passage is a groove that is recessed upward from the base-facing surface and extends from the point of communication with the internal passage to the discharge opening surface. Manufacturing method for turbine components.

10. In the method for manufacturing a turbine component according to claim 8, The discharge passage is located in the additively fabricated object in a portion closer to the base plate, and is situated above the base-facing surface, extending from the point of communication with the internal passage to the discharge opening surface. Manufacturing method for turbine components.

11. In the method for manufacturing a turbine component according to claim 8, The aforementioned discharge passage has a first discharge passage and a second discharge passage. The first discharge passage is a groove that communicates with the internal passage at the end of the internal passage on the base plate side, is recessed upward from the base-facing surface, and extends from the communication position with the internal passage to the first discharge opening surface which serves as the discharge opening surface. The second discharge passage communicates with the internal passage at a point closer to the base plate than the first discharge passage, and extends from the point of communication with the internal passage to the second discharge opening surface, which serves as the discharge opening surface. The second discharge opening surface is one of the plurality of outer surfaces, excluding the base-facing surface and the first discharge opening surface. Both the first discharge opening surface and the second discharge opening surface are outer surfaces, among a plurality of outer surfaces, that are connected to the edge of the base-facing surface. Manufacturing method for turbine components.

12. In the method for manufacturing a turbine component according to claim 8, The finishing step includes a discharge passage forming portion removal step, in which the portion of the additively manufactured product that includes the base-facing surface and the discharge passage is removed. Manufacturing method for turbine components.

13. In the method for manufacturing a turbine component according to any one of claims 1 to 4, After any one of the steps of the powder removal step, the heat treatment step, and the plate removal step, a discharge opening closing step is performed to close the discharge opening of the discharge passage. Manufacturing method for turbine components.

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