A turbine disk shaft and a welding method thereof

Abstract

The application discloses a turbine disc shaft and a welding method thereof, relates to the technical field of aero-engine rotor components, and the turbine disc shaft comprises a turbine disc made of cast high-temperature alloy material and a turbine shaft made of hot-strength stainless steel or deformed high-temperature alloy material. The turbine shaft is divided into a first shaft section and a second shaft section. The first end of the first shaft section is connected with the turbine disc through friction welding to form a first weld seam, and the second end is connected with the second shaft section through electron beam welding to form a second weld seam. The three parts jointly enclose a closed inner cavity, and the inner side surface of the first weld seam is a smooth curved surface. Since the first shaft section is in a through and open state before electron beam welding, the inner side flash generated by friction welding can be removed through turning, stress concentration is avoided, the high-quality welding of dissimilar materials and stress control of the closed inner cavity structure are taken into account, and the fatigue resistance and service life of the welded joint are effectively improved.

Description

Technical Field

[0001] This application relates to the field of aero-engine rotor component technology, and more specifically, to a turbine disk shaft and its welding method. Background Technology

[0002] The turbine disk shaft structure is a core component of the aero-engine rotor, typically formed by welding the turbine disk and turbine shaft. Because turbine disks are often made of cast high-temperature alloys, while turbine shafts are made of heat-resistant steel or wrought high-temperature alloys, the significant differences in the physicochemical properties of these two materials make it difficult to obtain defect-free, high-quality welds when welding cast high-temperature alloys using traditional fusion welding methods. This is because cast high-temperature alloys contain a large number of strengthening elements, resulting in a high tendency for hot cracking and extremely poor weldability.

[0003] Therefore, to ensure connection quality, inertial friction welding, a solid-state welding method, is chosen to effectively avoid metallurgical defects such as solidification cracks caused by fusion welding. However, because the turbine disk shaft has a closed internal cavity structure, the burrs that inevitably form on the inside of the weld during inertial friction welding cannot be removed by machining. This results in burrs remaining at the weld root, forming sharp geometric discontinuities and causing significant stress concentration, thereby reducing the fatigue strength and service life of the welded joint under alternating loads.

[0004] In summary, how to reduce stress concentration at the turbine disc shaft weld and extend its service life is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a turbine disk shaft and its welding method, which reduces stress concentration at the weld of the turbine disk shaft and extends its service life.

[0006] To achieve the above objectives, this application provides the following technical solution: A turbine disk shaft includes: a turbine disk made of cast high-temperature alloy; and a turbine shaft made of heat-resistant stainless steel or wrought high-temperature alloy. The turbine shaft includes a first shaft segment and a second shaft segment. A first end of the first shaft segment is connected to the turbine disk by friction welding to form a first weld. A second end of the first shaft segment is connected to the second shaft segment by electron beam welding to form a second weld. The turbine disk, the first shaft segment, and the second shaft segment together form a closed inner cavity. The inner surface of the first weld is a smooth rotating surface.

[0007] In some embodiments, the turbine disk includes a turbine disk body with an integral structure and an annular boss protruding from the turbine disk body; the end face of the annular boss is a first friction welding surface of an annular shape, and the first friction welding surface abuts against the first end face of the first shaft segment.

[0008] In some embodiments, the first shaft segment has a through cylindrical structure; the first end of the first shaft segment has a second friction welding surface, the second friction welding surface is an annular surface that matches the first friction welding surface, and the first friction welding surface and the second friction welding surface are connected by friction welding to form the first weld.

[0009] In some embodiments, the second end of the first shaft segment has a first electron beam welding surface, which is an annular surface; the end of the second shaft segment connected to the first shaft segment forms a butt joint; the butt joint has a second electron beam welding surface, which is an annular surface that matches the first electron beam welding surface; the first electron beam welding surface and the second electron beam welding surface are connected by electron beam welding to form the second weld.

[0010] In some embodiments, the mating joint has a stop structure at one end facing the first shaft segment; the inner wall of the second end of the first shaft segment fits against the outer wall of the stop structure, and the end face of the second end of the first shaft segment abuts against and is positioned with the bottom surface of the stop structure.

[0011] In some embodiments, the inner cavity of the annular boss, the hollow inner cavity of the first shaft segment, and the inner cavity of the mating joint are sequentially connected and together form the closed inner cavity.

[0012] In some embodiments, the turbine disk, the first shaft segment, and the second shaft segment are aligned.

[0013] In some embodiments, along the axial direction, the axial dimension of the first shaft segment is smaller than the axial dimension of the second shaft segment.

[0014] In some embodiments, the turbine disk is made of K418B cast high-temperature alloy or K417G cast high-temperature alloy; the turbine shaft is made of 1Cr11Ni2W2MoV heat-resistant stainless steel.

[0015] A welding method for a turbine disk shaft includes: providing a turbine disk and a turbine shaft, the turbine shaft comprising a first shaft segment and a second shaft segment, the turbine disk being made of cast high-temperature alloy, and the first shaft segment and the second shaft segment being made of heat-resistant stainless steel or wrought high-temperature alloy; clamping the turbine disk on the moving end of a friction welding machine, clamping the first shaft segment on the rotating end of the friction welding machine, rotating the first shaft segment to reach the friction welding speed, controlling the welding surfaces of the turbine disk and the first shaft segment to gradually approach and contact each other, and connecting the turbine disk and the first end of the first shaft segment by friction welding under axial force to form a first weld; machining to remove the burrs on the inner and outer surfaces of the first weld; positioning and fitting the second end of the first shaft segment and the second shaft segment through a stop structure, then placing them in the vacuum chamber of an electron beam welding machine, performing electron beam welding after vacuuming, and achieving full-circumference welding by rotating a rotary table to form a second weld, thereby achieving the welding of the turbine disk and the turbine shaft.

[0016] The turbine disk shaft provided in this application includes a turbine disk and a turbine shaft. The turbine disk is made of cast high-temperature alloy, and the turbine shaft is made of heat-resistant stainless steel or wrought high-temperature alloy. The turbine shaft includes a first shaft segment and a second shaft segment. The first end of the first shaft segment is connected to the turbine disk by friction welding to form a first weld, and the second end of the first shaft segment is connected to the second shaft segment by electron beam welding to form a second weld. The turbine disk, the first shaft segment, and the second shaft segment together form a closed inner cavity, and the inner surface of the first weld is a smooth rotating surface.

[0017] In this way, by forming the first and second shaft segments and combining friction welding and electron beam welding, the friction welding between the turbine disk shaft and the first shaft segment effectively avoids the problems of high thermal cracking tendency and poor weldability of cast high-temperature alloys during fusion welding, ensuring a high-quality connection of dissimilar material interfaces. The electron beam welding between the first and second shaft segments ensures stable welding quality and small deformation, guaranteeing the structural strength and dimensional accuracy of the entire shaft. At the same time, the first shaft segment is in an open state after friction welding and before electron beam welding, providing accessible operating space for machining tools. This allows the flash on the inner side of the first weld, which was originally located in the dead corner of the closed cavity, to be removed by conventional turning, making the inner surface of the first weld a smooth rotating surface. This eliminates the sharp geometric discontinuities formed at the root of the flash, effectively avoiding stress concentration and significantly improving the fatigue resistance and service life of the welded joint under alternating loads. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the turbine disk shaft provided in an embodiment of this application; Figure 2 This is a schematic diagram showing the connection between the turbine disk and the first shaft segment provided in an embodiment of this application; Figure 3 A schematic diagram of a turbine disk provided for an embodiment of this application; Figure 4 A schematic diagram of the first shaft segment provided in an embodiment of this application; Figure 5 This is a schematic diagram of the second shaft segment provided in an embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 100-Turbine disk, 110-Turbine disk body, 120-Annular boss, 121-First friction welding surface; 200 - Turbine shaft, 210 - First shaft section, 211 - Second friction welding surface, 212 - First electron beam welding surface, 220 - Second shaft section, 221 - Second electron beam welding surface; 300 - First weld; 400 - Second weld. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to be a limitation of this application. As used in the specification and appended claims of this application, the singular expressions "a," "an," "the," "the," "the," and "this" are intended to also include expressions such as "one or more," unless the context clearly indicates otherwise. It should also be understood that in the embodiments of this application, "one or more" refers to one, two, or more; "and / or" describes the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0023] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0024] The "multiple" mentioned in the embodiments of this application refers to two or more. It should be noted that in the description of the embodiments of this application, terms such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0025] In aero-engine rotor components, the turbine disk-shaft structure is typically formed by welding the turbine disk and turbine shaft. Because the turbine disk operates in a high-temperature, high-pressure environment, cast high-temperature alloys are often used; the turbine shaft, on the other hand, is made of heat-resistant stainless steel or wrought high-temperature alloys. When welding cast high-temperature alloys using fusion welding, the material contains a large number of strengthening elements, resulting in a high tendency for hot cracking, poor weldability, and difficulty in obtaining defect-free, high-quality welds. While inertial friction welding can effectively avoid the solidification cracking problem of fusion welding, for closed internal cavity structures, the flash formed on the inner side of the weld during friction welding is located in the dead corner of the cavity, making it impossible for conventional tools to reach and remove it. This flash residue forms sharp geometric discontinuities, causing severe stress concentration and significantly reducing the fatigue strength and service life of the welded joint under alternating loads.

[0026] Based on this, this application provides a turbine disk shaft and a welding method for the turbine disk shaft. The turbine disk shaft is designed as a split structure, with the first shaft segment in an open, continuous state after friction welding and before electron beam welding. This provides accessible operating space for the machining tool, allowing the flash, which would otherwise be located in the dead corner of the closed cavity, to be removed by conventional turning. After removing the flash, the second shaft segment is welded to the second end of the first shaft segment using electron beam welding, ultimately forming a closed cavity. This method utilizes the advantages of solid-state friction welding to avoid the hot cracking problem of fusion welding in cast high-temperature alloys, and solves the industry problem of the inability to remove flash within the friction weld in closed cavity structures. It effectively reduces stress concentration at the weld, improving the fatigue resistance and service life of the welded joint.

[0027] like Figure 1 As shown, the turbine disk shaft provided in this embodiment includes a turbine disk 100 and a turbine shaft 200. The turbine disk 100 is made of cast high-temperature alloy, and the turbine shaft 200 is made of heat-resistant stainless steel or wrought high-temperature alloy. The turbine shaft 200 includes a first shaft segment 210 and a second shaft segment 220. The first shaft segment 210 has a first end and a second end, wherein the first end is connected to the turbine disk 100 by friction welding to form a first weld 300. One end of the second shaft segment 220 is connected to the second end of the first shaft segment 210 by electron beam welding to form a second weld 400. The turbine disk 100, the first shaft segment 210, and the second shaft segment 220 together form a closed inner cavity. The inner surface of the first weld 300 is a smooth rotating surface.

[0028] The smooth rotating surface of the inner side of the first weld 300 is formed by machining to remove the internal flash generated during friction welding, resulting in a smooth rotating surface. Under stress, it will not produce significant stress concentration, which is beneficial to improving the fatigue strength of the welded joint.

[0029] like Figures 2-4 As shown, the turbine disk 100 includes a one-piece turbine disk body 110 and an annular boss 120 protruding from the end face of the turbine disk body 110. The annular boss 120 protrudes along the axial direction of the turbine disk 100 toward the first shaft segment 210. The end face of the annular boss 120 is a circular first friction welding surface 121. This first friction welding surface 121 is used to abut against the first end face of the first shaft segment 210 to form a friction welding mating surface.

[0030] The first shaft segment 210 has a through cylindrical structure, with a hollow inner cavity along its axial direction and through openings at both ends. The first end of the first shaft segment 210 has a second friction welding surface 211. The second friction welding surface 211 is an annular surface that matches the first friction welding surface 121. The first friction welding surface 121 and the second friction welding surface 211 are connected by friction welding to form a first weld 300.

[0031] like Figures 4-5 As shown, the second end of the first shaft segment 210 has a first electron beam welding surface 212. The first electron beam welding surface 212 is an annular surface. Figure 5 As shown, a butt joint is formed at one end of the second shaft segment 220 that connects to the first shaft segment 210. This butt joint has a second electron beam welding surface 221, which is an annular surface that matches the first electron beam welding surface 212. The first electron beam welding surface 212 and the second electron beam welding surface 221 are connected by electron beam welding to form a second weld 400.

[0032] like Figure 5 As shown, the butt joint has a stop structure at one end facing the first shaft segment 210. The inner wall of the second end of the first shaft segment 210 fits against the outer wall of the stop structure, and the end face of the second end of the first shaft segment 210 abuts against the bottom surface of the stop structure for positioning. Through the cooperation of this stop structure, the radial and axial positioning of the first shaft segment 210 and the second shaft segment 220 can be achieved before electron beam welding, ensuring that the coaxiality and end face gap between them meet the process requirements of electron beam welding. Due to the stop positioning structure, the relative position between the two shaft segments can be maintained without additional positioning fixtures during electron beam welding, which simplifies the welding fixtures and improves the welding accuracy.

[0033] like Figure 1 As shown, in this application, the inner cavity of the annular boss 120, the hollow inner cavity of the first shaft segment 210, and the inner cavity of the docking joint are sequentially connected to form a closed inner cavity. This closed inner cavity is axially sealed at both ends by the turbine disk 100 and the second shaft segment 220, and radially enclosed by the inner walls of the annular boss 120, the first shaft segment 210, and the docking joint. This closed inner cavity can be used as a cooling gas passage in an aero-engine rotor, or to reduce rotor weight.

[0034] In this application, such as Figure 1 As shown, the turbine disk 100, the first shaft section 210 and the second shaft section 220 are aligned. By setting the three coaxially, the dynamic balance characteristics of the turbine disk shaft under high-speed rotation conditions are ensured, and the additional vibration and stress caused by eccentricity are reduced.

[0035] like Figure 1As shown, along the axial direction, the axial dimension of the first shaft segment 210 is smaller than that of the second shaft segment 220. The axial dimension of the first shaft segment 210 is mainly used to provide space for the friction welding connection area and the flash removal operation. Its length is configured to be as short as possible while ensuring that the flash removal tool can extend into the hollow cavity of the first shaft segment 210 and reach the inside of the first weld 300, so as to reduce material consumption and overall axial dimension. The axial dimension of the second shaft segment 220 is determined according to the overall design requirements of the turbine disk shaft.

[0036] In some embodiments, the turbine disk 100 is made of K418B or K417G cast superalloy. The turbine shaft 200 is made of 1Cr11Ni2W2MoV heat-resistant stainless steel. Both K418B and K417G cast superalloys possess excellent high-temperature strength and oxidation resistance, making them suitable for the working environment of aero-engine turbine disks. 1Cr11Ni2W2MoV heat-resistant stainless steel has good high-temperature strength, oxidation resistance, and machinability, making it suitable for the working environment of turbine shafts. It is understood that in other embodiments, the turbine shaft 200 may also be made of other wrought superalloys, such as GH4169.

[0037] In this application, the smooth rotating surface structure on the inner surface of the first weld 300 is formed by machining the inner flash of the first weld 300 before welding the second shaft segment 220. Since the first shaft segment 210 is still a cylindrical structure with both ends open at this time, the cutting tool can extend from the second end of the first shaft segment 210 into its hollow cavity to reach the inner surface of the first weld 300 and remove the flash. After machining, the inner surface of the first weld 300 forms a smooth rotating surface, eliminating the sharp geometric discontinuities formed at the root of the flash. Because the stress concentration factor of this smooth rotating surface is much lower than that of the surface with residual flash, it can significantly improve the fatigue life of the welded joint under alternating loads.

[0038] This application embodiment also provides a welding method for a turbine disk shaft, including: S100 provides a turbine disk 100 and a turbine shaft 200, the turbine shaft 200 including a first shaft section 210 and a second shaft section 220. The turbine disk 100 is made of cast high-temperature alloy, and the first shaft section 210 and the second shaft section 220 are both made of heat-resistant stainless steel or wrought high-temperature alloy.

[0039] S200: Clamp the turbine disk 100 onto the moving end of the friction welding machine, and clamp the first shaft segment 210 onto the rotating end of the friction welding machine. Rotate the first shaft segment 210 to reach the friction welding speed. Control the welding surfaces of the turbine disk 100 and the first shaft segment 210 to gradually approach and contact each other. Under the action of axial force, connect the turbine disk 100 and the first end of the first shaft segment 210 through friction welding to form the first weld 300.

[0040] Specifically, the turbine disk 100 is placed and clamped in the moving end fixture of the friction welding machine, and the first shaft segment 210 is placed and clamped in the rotating end fixture of the friction welding machine, so that the first shaft segment 210 and the turbine disk 100 are on the same central axis. The friction welding machine is started, causing the first shaft segment 210 to rotate at high speed and reach the preset friction welding speed. Then, the moving end is driven to move the turbine disk 100 toward the first shaft segment 210, so that the first friction welding surface 121 of the turbine disk 100 and the second friction welding surface 211 of the first shaft segment 210 gradually approach and contact each other. After contact, an axial force is applied, causing the two welding surfaces to undergo thermoplastic deformation under the combined action of frictional heat and axial pressure, and finally welded together to form the first weld 300.

[0041] S300, the flash on the inner and outer surfaces of the first weld 300 is removed by turning.

[0042] Since the first shaft segment 210 is a through structure, the cutting tool can extend from the second end of the first shaft segment 210 into its hollow cavity to machine the inner surface of the first weld 300. Simultaneously, the flash on the outer surface of the first weld 300 can be removed by turning from the outside. After removing the flash, both the inner and outer surfaces of the first weld 300 are smooth surfaces of revolution. Removing the flash by turning eliminates the stress concentration caused by it.

[0043] Specifically, the turbine disk 100 and the first shaft segment 210 are welded together and clamped on a lathe. According to the preset machining dimensions, the flash on the inner and outer surfaces of the first weld 300 is removed by turning. The turning process can use conventional carbide cutting tools, and the machining parameters are selected based on the material type and flash size. For turning the inner surface flash, since the first shaft segment 210 is a through structure, the cutting part of the tool can easily reach the inner surface of the first weld 300.

[0044] S400: The second end of the first shaft segment 210 and the second shaft segment 220 are positioned and fitted together by a stop structure, and then installed into the vacuum chamber of the electron beam welding machine. After vacuuming, electron beam welding is performed, and full-circumference welding is achieved by rotating the rotary table to form the second weld 400, thereby achieving the welding of the turbine disk 100 and the turbine shaft 200.

[0045] Specifically, the turbine disk 100, the welding assembly of the first shaft segment 210, and the second shaft segment 220 are assembled in a welding fixture and fixed to an electron beam welding rotary table using the welding fixture. The mating joint between the second end of the first shaft segment 210 and the second shaft segment 220 is radially and axially positioned using a stop structure. The rotary table is pushed into the vacuum chamber, the vacuum chamber door is closed, and vacuuming begins, raising the vacuum chamber to a preset vacuum level. After vacuuming is complete, the electron beam welding machine is started for electron beam welding. Through the rotation of the rotary table, the entire circumferential mating surfaces of the first shaft segment 210 and the second shaft segment 220 are sequentially irradiated by the electron beam, achieving full-circumferential welding and forming the second weld 400.

[0046] During electron beam welding, since the first shaft segment 210 and the second shaft segment 220 are made of the same material, there are no metallurgical compatibility issues associated with welding dissimilar materials. The penetration depth and width of the electron beam weld are easily controlled, resulting in stable and reliable weld quality. After electron beam welding, the turbine disk 100, the first shaft segment 210, and the second shaft segment 220 together form a closed inner cavity. The inner wall surface of this closed cavity is smooth, without any burrs or other sharp protrusions, thus preventing significant stress concentration during service.

[0047] The technical solution of this application will be further described below with reference to specific embodiments.

[0048] Example 1

[0049] The turbine disk 100 is made of K418B cast high-temperature alloy, the first shaft section 210 is made of 1Cr11Ni2W2MoV heat-resistant stainless steel, and the second shaft section 220 is made of 1Cr11Ni2W2MoV heat-resistant stainless steel.

[0050] The K418B turbine disk 100 is placed and clamped in the moving end fixture of the friction welding machine. The first shaft segment 210 of 1Cr11Ni2W2MoV is placed and clamped in the rotating end fixture of the friction welding machine, so that the first shaft segment 210 and the K418B turbine disk 100 are on the same central axis. The friction welding machine is started, and the first shaft segment 210 is rotated to the friction welding speed. The moving end is driven to move the turbine disk 100 toward the first shaft segment 210, so that the second friction welding surface 211 of the first shaft segment 210 and the first friction welding surface 121 of the turbine disk 100 gradually approach and contact each other. Under the action of axial force, the two welding surfaces undergo friction and thermoplastic deformation, and finally weld together to form the first weld 300.

[0051] The welding assembly is clamped on a lathe, and the flash on the inner and outer surfaces of the first weld 300 is removed by turning according to the machining dimensions. Since the first shaft section 210 is a through structure, the cutting tool can extend from the second end of the first shaft section 210 into the hollow cavity to reach the inner surface of the first weld 300 for turning to remove the inner flash. At the same time, the outer flash is removed by turning from the outside.

[0052] The turbine disk 100, after removing the flash, is welded together with the first shaft segment 210 and the second shaft segment 220 (1Cr11Ni2W2MoV). The second end of the first shaft segment 210 and the butt joint of the second shaft segment 220 are positioned and fitted by a stop structure. The assembly is fixed on the electron beam welding rotary table using welding fixtures. The rotary table is pushed into the vacuum chamber, the vacuum chamber door is closed, and vacuuming begins. After vacuuming is complete, electron beam welding is performed. By rotating the rotary table, the first shaft segment 210 and the second shaft segment 220 are welded together around their circumference, forming the second weld 400. After welding, the turbine disk 100, the first shaft segment 210, and the second shaft segment 220 together form a closed inner cavity, and the inner surface of the first weld 300 is a smooth rotating surface.

[0053] Example 2

[0054] The turbine disk 100 is made of K417G cast high-temperature alloy, the first shaft section 210 is made of 1Cr11Ni2W2MoV heat-resistant stainless steel, and the second shaft section 220 is made of 1Cr11Ni2W2MoV heat-resistant stainless steel.

[0055] The K417G turbine disk 100 is placed and clamped in the moving end fixture of the friction welding machine. The first shaft segment 210 of 1Cr11Ni2W2MoV is placed and clamped in the rotating end fixture of the friction welding machine, so that the first shaft segment 210 and the K417G turbine disk 100 are on the same central axis. The friction welding machine is started, and the first shaft segment 210 is rotated to the friction welding speed. The moving end is driven to move the turbine disk 100 toward the first shaft segment 210, so that the second friction welding surface 211 of the first shaft segment 210 and the first friction welding surface 121 of the turbine disk 100 gradually approach and contact each other. Under the action of axial force, the two welding surfaces undergo friction and thermoplastic deformation, and finally weld together to form the first weld 300.

[0056] The welding assembly is clamped on a lathe, and the flash on the inner and outer surfaces of the first weld seam 300 is removed by turning according to the machining size requirements.

[0057] The turbine disk 100, after removing the flash, is welded together with the first shaft segment 210 and the second shaft segment 220 (1Cr11Ni2W2MoV). The second end of the first shaft segment 210 and the butt joint of the second shaft segment 220 are positioned and fitted by a stop structure. The assembly is fixed on the electron beam welding rotary table using welding fixtures. The rotary table is pushed into the vacuum chamber, the vacuum chamber door is closed, and vacuuming begins. After vacuuming is complete, electron beam welding is performed. By rotating the rotary table, the first shaft segment 210 and the second shaft segment 220 are welded together around their circumference, forming the second weld 400. After welding, the turbine disk 100, the first shaft segment 210, and the second shaft segment 220 together form a closed inner cavity, and the inner surface of the first weld 300 is a smooth rotating surface.

[0058] In the above embodiment, by setting the turbine shaft 200 as a split structure of the first shaft segment 210 and the second shaft segment 220, the turbine disk 100 and the first shaft segment 210 are first connected by friction welding. Then, in the open state, the inner flash of the first weld 300 is removed by machining. Finally, the second shaft segment 220 is connected to the first shaft segment 210 by electron beam welding to form a closed inner cavity. The entire process ensures high-quality welding between the cast high-temperature alloy and the heat-resistant stainless steel dissimilar materials, and solves the technical problem of removing the inner flash in the closed inner cavity structure. The resulting turbine disk shaft has both a closed inner cavity structure to meet the design requirements of aero-engines and a smooth weld inner surface to avoid stress concentration, significantly improving the reliability and service life of the product.

[0059] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A turbine disk shaft, characterized in that, include: Turbine disk (100), wherein the material of the turbine disk (100) is a cast high-temperature alloy; Turbine shaft (200), wherein the material of the turbine shaft (200) is heat-resistant stainless steel or wrought high-temperature alloy; The turbine shaft (200) includes a first shaft section (210) and a second shaft section (220); The first end of the first shaft segment (210) is connected to the turbine disk (100) by friction welding to form a first weld (300). The second end of the first shaft segment (210) is connected to the second shaft segment (220) by electron beam welding to form a second weld (400). The turbine disk (100), the first shaft segment (210), and the second shaft segment (220) together form a closed inner cavity; The inner surface of the first weld (300) is a smooth rotating surface.

2. The turbine disk shaft according to claim 1, characterized in that, The turbine disk (100) includes a turbine disk body (110) with an integral structure and an annular boss (120) protruding from the turbine disk body (110). The end face of the annular boss (120) is a first friction welding surface (121) that is circular, and the first friction welding surface (121) abuts against the first end face of the first shaft segment (210).

3. The turbine disk shaft according to claim 2, characterized in that, The first shaft segment (210) has a through cylindrical structure; The first end of the first shaft segment (210) has a second friction welding surface (211), which is an annular surface that matches the first friction welding surface (121). The first friction welding surface (121) and the second friction welding surface (211) are connected by friction welding to form the first weld (300).

4. The turbine disk shaft according to claim 3, characterized in that, The second end of the first shaft segment (210) has a first electron beam welding surface (212), which is an annular surface; The end of the second shaft segment (220) that connects to the first shaft segment (210) forms a butt joint; The mating joint has a second electron beam welding surface (221), which is an annular surface that matches the first electron beam welding surface (212). The first electron beam welding surface (212) and the second electron beam welding surface (221) are connected by electron beam welding to form the second weld (400).

5. The turbine disk shaft according to claim 4, characterized in that, The end of the mating joint facing the first shaft segment (210) is provided with a stop structure; The inner wall of the second end of the first shaft segment (210) is in contact with the outer wall of the stop structure, and the end face of the second end of the first shaft segment (210) is in contact with the bottom surface of the stop structure for positioning.

6. The turbine disk shaft according to claim 4, characterized in that, The inner cavity of the annular boss (120), the hollow inner cavity of the first shaft segment (210), and the inner cavity of the mating joint are sequentially connected and together form the closed inner cavity.

7. The turbine disk shaft according to claim 1, characterized in that, The axes of the turbine disk (100), the first shaft segment (210), and the second shaft segment (220) are aligned.

8. The turbine disk shaft according to claim 7, characterized in that, Along the axial direction, the axial dimension of the first shaft segment (210) is smaller than the axial dimension of the second shaft segment (220).

9. The turbine disk shaft according to claim 1, characterized in that, The turbine disk (100) is made of K418B cast high-temperature alloy or K417G cast high-temperature alloy. The turbine shaft (200) is made of 1Cr11Ni2W2MoV heat-resistant stainless steel.

10. A welding method for a turbine disk shaft, characterized in that, include: A turbine disk (100) and a turbine shaft (200) are provided. The turbine shaft (200) includes a first shaft section (210) and a second shaft section (220). The turbine disk (100) is made of cast high-temperature alloy. The first shaft section (210) and the second shaft section (220) are both made of heat-resistant stainless steel or wrought high-temperature alloy. The turbine disk (100) is clamped on the moving end of the friction welding machine, and the first shaft segment (210) is clamped on the rotating end of the friction welding machine. The first shaft segment (210) is rotated and reaches the friction welding speed. The welding surfaces of the turbine disk (100) and the first shaft segment (210) are controlled to gradually approach and contact each other. Under the action of axial force, the turbine disk (100) and the first end of the first shaft segment (210) are connected by friction welding to form the first weld (300). The flash on the inner and outer surfaces of the first weld (300) is removed by machining. After the second end of the first shaft segment (210) and the second shaft segment (220) are positioned and fitted by the stop structure, they are installed in the vacuum chamber of the electron beam welding machine. After evacuation, electron beam welding is performed. The entire circumference is welded by rotating the rotating worktable to form the second weld (400) so as to achieve the welding of the turbine disk (100) and the turbine shaft (200).

Images