Method and product for controlling electron beam welding distortion of a planetary weld

Abstract

The present application relates to the technical field of welding, in particular to a kind of planetary weld electron beam welding deformation control method and product, comprising the following steps: S1, the part to be welded and welding fixture are cleaned;S2, the part to be welded is assembled, and the angular direction of the part to be welded and the round jump at weld are detected;S3, the part to be welded and welding fixture are assembled, and installed on electron beam welding machine;S4, welding is carried out at weld;S5, visual inspection is carried out on the part after welding, vacuum eliminates welding stress, ray detection and fluorescence detection are carried out.The present application can provide a complete welding process and welding parameters for the part with small threshold welding thickness and strict welding deformation requirement, effectively prevent the deformation of the part, avoid the problem of part scrapping caused by welding through and hitting the inside of flow channel, which is difficult to repair.

Description

Technical Field

[0001] This invention relates to the field of welding technology, specifically to a method and product for controlling deformation during electron beam welding of planetary welds. Background Technology

[0002] A certain aero-engine combustion chamber component consists of a final stage stator and a pre-diffuser, connected by two electron beam welds. The component structure is as follows: Figure 1 As shown. The upper end of the final stage stator is closed, and the weld is similar to an inverted "U" shape. The bottom end of the pre-diffuser is closed, and the weld is similar to a "U" shape.

[0003] CN111702317A discloses an electron beam welding method for a double-sided planetary weld structure, comprising the following steps: Step 1, splicing the welding end faces of two parts to form a welding assembly; Step 2, cleaning the welding surface; Step 3, determining the welding parameters, including welding voltage, focusing current, welding speed, weld thickness, and a circular function; Step 4, welding the welding assembly using the welding parameters of Step 3. The parts employ interference fit and specialized welding fixtures to ensure the weld gap and axial and radial runout values. Regarding the welding method, multi-point symmetrical electron beam tack welding is performed on the front side, and immediately after the front tack welding is completed, multi-point symmetrical electron beam tack welding is performed on the back side. After all tack welding is completed, the weld is sequentially sealed and then formally welded to effectively avoid welding defects such as misalignment, cracks, dents, and damage caused by tensile stress. By adjusting the welding current and focusing current and adding a circular function, while retaining the locking bottom, easily occurring welding defects such as spike defects and porosity are effectively avoided, thus improving the welding quality of the parts.

[0004] However, the back of the weld seam of this part has a cavity structure with flow channels inside, which must be kept clean. Due to the special structure of the part, if spatter is generated inside the cavity after welding, it cannot be guaranteed to be completely removed. Therefore, it is required that no weld slag or other residues be generated during welding. The main difficulties in welding this part are as follows: the two weld seams, inner and outer, are about 20mm apart, and the weld thickness is relatively thin, making them prone to deformation during welding; both weld seams must ensure an effective welding depth (2.6mm) and cannot penetrate the part (4.0mm), so the threshold is only 1.4mm, and the electron beam fluctuates, making it difficult to select welding methods and parameters. Summary of the Invention

[0005] To address the problem that welding of certain cavity parts with planetary weld structures in the prior art cannot meet quality requirements, this invention provides a method and product for controlling deformation during electron beam welding of planetary welds.

[0006] This invention is achieved through the following technical solution: A method for controlling deformation during electron beam welding of planetary welds, comprising the following steps: S1, Clean the parts to be welded and the welding fixture; S2, Assemble the parts to be welded and check the angularity of the parts to be welded and the round runout at the weld; S3, assemble the parts to be welded and the welding fixture, and install them on the electron beam welding machine; S4, Welding is performed at the weld seam; S5 involves visual inspection, vacuum stress relief, radiographic testing, and fluorescence testing of the welded parts.

[0007] Preferably, in S1, acetone solution is used to wipe the area of ​​the joint to be welded on the parts to be welded during cleaning; The back of the welded joint has a cavity structure, the bottom lock is Z-shaped, and the distance between the bottom lock and the weld is 1~1.5mm.

[0008] Preferably, in S1, the welding fixture includes an intermediate plate, an outer pressure plate, and an inner pressure plate, with the outer pressure plate and the inner pressure plate respectively fixed to the outer and inner sides of the intermediate plate by a detachable structure.

[0009] Preferably, an elongated groove is provided on the intermediate plate, and the outer pressure plate and the inner pressure plate are connected to the intermediate plate through the elongated groove using a detachable structure.

[0010] Preferably, in S4, during welding, multi-point welding is performed at the weld joint in a diagonal welding manner, wherein weld joint forms a “Z” shaped weld I and weld II, weld I forming a 30° angle with the horizontal direction, and weld II being a horizontal weld.

[0011] Preferably, the specific welding steps are as follows: S41, use the inner pressure plate to clamp the parts and perform tack welding on weld seam I; S42, replace with outer pressure plate clamping parts, and perform tack welding, sealing welding and formal welding on weld II in sequence; S43; Then replace with inner pressure plate clamping parts, and perform sealing welding and formal welding on weld seam I in sequence.

[0012] Preferably, in S41, during tack welding, one point is fixed at every 45°, for a total of 8 points.

[0013] Preferably, in S42, during tack welding, one point is fixed at every 45°, for a total of 8 points; Select the 0° position of the part for sealing welding, start the arc at 20°, and end the arc at 20°; Select the part at a 180° position for the formal welding, start the arc at 20° and end the arc at 20°.

[0014] Preferably, in S43, the part is selected at the 0° position for sealing welding, the arc is started at 20°, and the arc is terminated at 20°; Select the part at a 180° position for the formal welding, start the arc at 20° and end the arc at 20°.

[0015] A product obtained according to the electron beam welding deformation control method for planetary welds.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for controlling deformation during electron beam welding of planetary welds. Based on the structural characteristics of the parts, and combining joint design, parameter selection, tooling design, welding method design, and step arrangement, this method offers a comprehensive approach to controlling deformation during electron beam welding of planetary welds. It incorporates pre-weld preparation design, welding process, and post-weld treatment methods, providing a reference for parts with small threshold welding thickness and strict requirements for welding deformation.

[0017] Furthermore, the locking bottom of the welded joint was changed from the original convex shape to a "Z" shape. This is because the convex shape affects the flow channel, while the "Z" shaped locking bottom is integrated into the wall thickness of the part. Also, the locking bottom should not be too close to the weld. When the weld quality is inspected by X-ray in the subsequent process, the black line of the locking bottom is easily confused with the weld, which affects the judgment of the weld quality.

[0018] Furthermore, the design of the welding fixture is based on the fact that during the welding of the outer weld, the enormous heat input from the electron beam is conducted along the part to the inner weld. The inner weld is heated and squeezed and curled in the opposite direction. At this time, the fixture is in a compressed state, and the deformation is not significant. After the outer weld is welded and the fixture is removed, the clamping force on the part itself and the inner weld decreases sharply, making the inner weld prone to deformation. This results in substandard butt joint and fitting gaps, and welding defects such as misalignment and porosity after welding. Therefore, the part needs to be kept in a compressed state when welding two welds. Based on this, without interfering with the electron beam, a welding fixture is proposed that continuously clamps the part and suppresses part deformation by changing the inner and outer pressure plates.

[0019] Furthermore, the choice of welding method is to minimize welding deformation and control the tensile deformation of the unwelded area towards the start of the weld.

[0020] Furthermore, the selection of welding parameters is to ensure welding quality. This is because the stress that causes deformation in the part comes from two sources. First, it comes from the shrinkage stress generated by metal fusion and solidification; the wider the weld, the greater the stress, and the slower the welding speed, the greater the shrinkage stress. Second, the stress comes from the difference in width between the upper and lower weld influence zones; assuming the same material, the greater the difference in zone width, the greater the resulting stress. Attached Figure Description

[0021] Figure 1This is a process flow diagram of an electron beam welding deformation control method for planetary welds according to the present invention. Figure 2 This is a schematic diagram of the weld seam in this invention; Figure 3 This is a schematic diagram of the welding fixture in the electron beam welding deformation control method for planetary welds of the present invention.

[0022] In the diagram, 1 is the middle plate; 2 is the inner pressure plate; 3 is the outer pressure plate; 4 is the screw; and 5 is the annular protrusion. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0024] This invention discloses a method for controlling deformation during electron beam welding of planetary welds, referring to... Figure 1 , 2 This includes the following steps: S1. Clean the parts to be welded and the welding fixtures; specifically, use acetone to clean the parts and welding fixtures to remove oil stains, and wipe the area of ​​the joint to be welded with a silk cloth soaked in acetone.

[0025] Among them, reference Figure 3 The welding fixture includes an intermediate plate 1, an outer pressure plate 3, and an inner pressure plate 2. The outer pressure plate 3 and the inner pressure plate 2 are fixed to the outer and inner sides of the intermediate plate 1 respectively by detachable structures (such as screws 4, nut structures, etc.).

[0026] An elongated groove 5 is provided on the intermediate plate 1, and the outer pressure plate 3 and the inner pressure plate 2 are connected to the intermediate plate 1 through the elongated groove 5 using a detachable structure.

[0027] Specifically, the intermediate plate 1 includes a detachably connected base plate and an annular protrusion 5. The annular protrusion 5 is connected to the base plate via a Z-shaped plate. The inner pressure plate 2 and the outer base plate 3 are located inside and outside the annular protrusion 5, respectively. The inner pressure plate is Z-shaped, with one end fixed to the base plate and the other end suspended above the annular protrusion 5. The outer pressure plate 3 is a horizontal plate, with one end fixed and the other end suspended above the annular protrusion 5. In use, parts are placed on the annular protrusion 5.

[0028] S2. Assemble the parts to be welded and use a coordinate measuring machine to check the angularity and weld runout of the parts to be welded, and check whether they are within the standard range. If they do not meet the requirements, the parts need to be disassembled, reassembled, and corrected until the requirements are met.

[0029] S3, assemble the parts to be welded and the welding fixture, and install them on the tilting and rotating turntable of the electron beam welding machine, then evacuate to ≤6×10. -4 bar.

[0030] S4, Welding is performed at the weld seam; during welding, a longitudinal electron gun is used, the accelerating voltage is 150kV, and the welding parameters are shown in Table 1.

[0031] The specific steps are as follows: S41, set the welding machine tilt angle to 90°, press the inner pressure plate to tighten the parts, perform tack welding on weld seam I, fix one point every 45°, for a total of 8 points, and release the vacuum.

[0032] S42, after clamping the part to full circumference using the outer pressure plate, remove the inner pressure plate, assemble the part onto the large disc, set the large disc tilt angle to 60°, and evacuate to ≤6×10. -4 For weld II, perform tack welding, marking 8 points at 45° intervals. Select the 0° position on the part for sealing welding (180°), starting the arc at 20° and ending at 20°. Select the 180° position on the part for formal welding (190°), starting the arc at 20° and ending at 20°. After formal welding, wait 5 minutes before purging to break the vacuum.

[0033] S43, after clamping the part to full circumference using the inner pressure plate, remove the outer pressure plate, assemble the part onto the large disc, set the large disc tilt angle to 90°, and evacuate to ≤6×10. -4 For weld I, perform a sealing weld, selecting the 0° position on the part for sealing (180°), starting the arc at 20° and ending at 20°. Then, perform the formal weld at the 180° position on the part (190°), starting the arc at 20° and ending at 20°. After the formal weld, wait 5 minutes before filling with gas to break the vacuum.

[0034] Table 1 Welding Parameters

[0035] S5 involves visual inspection, vacuum stress relief, radiographic testing, and fluorescence testing of the welded parts.

[0036] During visual inspection, the electronic weld should be visually inspected according to the standard. The weld surface should be smooth and transition smoothly to the base material. There should be no visible defects such as cracks, lack of fusion, incomplete penetration, burns, or burn-through.

[0037] During radiographic inspection, the welds shall be inspected according to standards. Defects such as cracks, lack of fusion, and incomplete penetration are not allowed inside the welds. Sharp-angled and linear pores, slag inclusions, and excessive pores are not permitted.

[0038] During fluorescence inspection, the weld should be radiographically inspected according to standards. Defects such as cracks, lack of fusion, and incomplete penetration are not permitted inside the weld. Sharp-angled and linear pores, slag inclusions, and excessive pore size are also not allowed.

[0039] Weld inspection is divided into radiographic testing and fluorescence testing. Common welding defects include porosity, slag inclusions, and cracks. Welding speed that is too fast can cause the gas in the molten pool or the gas trapped in it to condense during the upward discharge process, forming porosity.

[0040] Therefore, based on the above analysis, and considering the component structure requirements and electron beam welding characteristics, surface focusing should be selected, and no modification welding should be performed. During the actual welding process, a smaller scanning function should be added to stir the weld pool while minimizing heat input, eliminating gas and slag inclusions. As many measurement points as possible should be used to ensure the beam current is centered on the weld during welding. A compromise must be made regarding welding speed. Regarding current selection, after achieving the effective weld depth (2.6mm), the increase in weld depth should be minimized; therefore, the welding current should only be sufficient to just penetrate the effective weld depth.

[0041] The present invention also discloses a product obtained according to the electron beam welding deformation control method for planetary welds.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A method for controlling deformation during electron beam welding of planetary welds, characterized in that, Includes the following steps: S1, Clean the parts to be welded and the welding fixture; the back of the welding joint has a cavity structure, the bottom lock is "Z" shaped, and the distance between the bottom lock and the weld is 1~1.5mm; The welding fixture includes an intermediate plate, an outer pressure plate, and an inner pressure plate. The outer pressure plate and the inner pressure plate are fixed to the outer and inner sides of the intermediate plate respectively by a detachable structure. S2, Assemble the parts to be welded and check the angularity of the parts to be welded and the round runout at the weld; S3, assemble the parts to be welded and the welding fixture, and install them on the electron beam welding machine; During welding, multiple points of welding are performed at the weld joint using a fillet welding method. The weld joint forms a "Z"-shaped weld I and weld II. Weld I forms a 30° angle with the horizontal direction, and weld II is a horizontal weld. S4, Welding is performed at the weld seam; the welding speed is 960 mm / min, and the specific steps are as follows: S41, use the inner pressure plate to clamp the parts, and perform tack welding on weld seam I, with a welding current of 3.0mA; S42, replace with outer pressure plate clamping parts, and perform tack welding, sealing welding and formal welding on weld II in sequence. The welding current is 3.0mA during tack welding, 5.0mA during sealing welding, and 8.5mA during formal welding. S43; Then replace with inner pressure plate clamping parts, and perform sealing welding and formal welding on weld seam I in sequence. The welding current is 5.0mA during sealing welding and 8.5mA during formal welding. S5 involves visual inspection, vacuum stress relief, radiographic testing, and fluorescence testing of the welded parts.

2. The method for controlling deformation during electron beam welding of planetary welds according to claim 1, characterized in that, In S1, acetone solution is used to wipe the area of ​​the joint to be welded on the parts to be welded during cleaning.

3. The electron beam welding deformation control method for planetary welds according to claim 1, characterized in that, An elongated groove is provided on the middle plate, and the outer and inner pressure plates are connected to the middle plate through the elongated groove using a detachable structure.

4. The method for controlling deformation during electron beam welding of planetary welds according to claim 1, characterized in that, In S41, during tack welding, one point is fixed at every 45°, for a total of 8 points.

5. The electron beam welding deformation control method for planetary welds according to claim 1, characterized in that, In S42, during tack welding, one point is fixed at every 45°, for a total of 8 points; Select the 0° position of the part for sealing welding, start the arc at 20°, and end the arc at 20°; Select the part at a 180° position for the formal welding, start the arc at 20° and end the arc at 20°.

6. The electron beam welding deformation control method for planetary welds according to claim 1, characterized in that, In S43, select the 0° position of the part for sealing welding, start the arc at 20°, and end the arc at 20°; Select the part at 180° for the formal welding, start the arc at 20°, maintain it at 370° during welding, and end the arc at 20°.

7. A product obtained by the electron beam welding deformation control method for planetary welds according to any one of claims 1 to 6.

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