Method for inspection and control of electron beam welding of electroformed nickel dissimilar metal welds

Abstract

The application relates to the field of electron beam welding, and particularly discloses a thrust chamber electroforming assembly, which comprises an electroforming workpiece with a ring-shaped connecting end at one end, and an outer ring flange workpiece connected with the ring-shaped connecting end through electron beam welding, wherein an electron beam strikes the joint between the outer ring flange workpiece and the ring-shaped connecting end through the main body of the electroforming workpiece; the hole of the outer ring flange workpiece comprises a first hole structure, a second hole structure and a stepped end face connected between the first hole structure and the second hole structure; the hole wall of the first hole structure is matched with the outer side wall of the ring-shaped connecting end, the second hole structure is located on the side of the first hole structure away from the main body of the electroforming workpiece, and the aperture of the second hole structure is smaller than that of the first hole structure. The application also provides a scribe device, an electron beam welding deviation checking method, an electron beam welding system and a welding method, aiming to optimize the joint structure design, avoid the influence of a magnetic field on welding beam alignment, avoid welding deviation measures and improve the welding quality of electroformed nickel dissimilar metal.

Description

Technical Field

[0001] This application relates to the technical field of electron beam welding, and in particular to a method for inspecting and controlling electron beam welding deviation of electroformed nickel dissimilar metals. Background Technology

[0002] The electroformed thrust chamber assembly is a key component of the engine. The outer flange is connected to the electroformed nickel outer wall using electron beam welding, which is a dissimilar metal welding process. It is subjected to high temperature, high pressure, and high speed of gas flow and the resulting vibration and impact, and must meet the GJB1718A-2005 electron beam welding Class I weld standard.

[0003] Due to limitations in early electron beam welding equipment, reverse welding was performed using medium-pressure welding machines with shorter focal lengths. The main problem was that the upper nail head portion of the fused weld was removed during subsequent machining, leaving behind the nail tip portion, which could cause weld misalignment and reduce joint reliability. Therefore, the current technique of forward welding of electroformed workpieces (i.e., flange at the bottom) falls under the category of long-focal-length electron beam welding.

[0004] During manufacturing, cooling channels are first CNC milled into the inner wall of the spun copper alloy, and then an outer nickel metal wall is electroformed onto the cooling channels, forming a regenerative cooling sandwich structure. Due to the characteristics of the electroformed nickel material processing, a certain degree of magnetism is inevitably generated. Measurements revealed that the magnetism of the electroformed body is 2 × 10⁻⁶. －4 T to 5×10 －4 T has a significant impact on electron beam welding. A demagnetizing machine was used to demagnetize the electroformed body. Measurement results showed that the magnetic content of the surface parts was no greater than 2 × 10⁻⁶. －4 T should meet the requirements according to welding standards, but this refers to the electron beam current reaching a magnetic charge of no more than 2 × 10⁻⁶ under conditions unaffected by a magnetic field. －4 When welding a T-shaped workpiece, the electron beam passes through the entire body during forward welding. Before it reaches the weld, it is already affected by the magnetic field of the body and deflected, causing the beam spot to not accurately hit the weld and resulting in weld misalignment.

[0005] Electron beam welding is characterized by a nail-shaped weld, wider at the top and narrower at the bottom. Poor alignment or magnetic field interference, coupled with the differences in physicochemical properties between dissimilar metals during welding, can cause the electron beam to deflect to one side, resulting in weld misalignment. This may lead to root displacement of the weld, resulting in incomplete fusion at the root and failing to meet the Class I weld standard. Summary of the Invention

[0006] This application provides a thrust chamber electroforming assembly, a scribing device, a method for inspecting electron beam weld misalignment, an electron beam welding system, and a welding method. The purpose is to optimize the joint structure design, avoid the influence of the magnetic field on the alignment of the welding beam, and take measures to avoid weld misalignment, thereby improving the welding quality of electroformed nickel dissimilar metals.

[0007] In a first aspect, a thrust chamber electroforming assembly is provided, comprising:

[0008] An electroformed workpiece with an axisymmetric structure, the electroformed workpiece includes an annular connecting end located at one end of the electroformed workpiece;

[0009] The outer ring flange workpiece is connected to the annular connection end by electron beam welding, wherein the electron beam passes through the body of the electroformed workpiece and bombards the joint between the outer ring flange workpiece and the annular connection end.

[0010] The outer ring flange workpiece includes a first hole structure, a second hole structure, and a stepped end face. The stepped end face is connected between the first hole structure and the second hole structure. The hole wall of the first hole structure mates with the outer wall of the annular connection end. The second hole structure is located on the side of the first hole structure away from the electroformed workpiece body. The diameter of the second hole structure is smaller than the diameter of the first hole structure.

[0011] Compared with the prior art, the solution provided in this application has at least the following beneficial technical effects:

[0012] By designing a reasonable joint structure, the problem of weld misalignment in electron beam welding of dissimilar metals was effectively solved, thus improving the welding quality.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, h2 = (1 / 3 to 2 / 3)h1, where h2 is the hole wall height of the second hole structure and h1 is the welding depth.

[0014] A well-designed joint structure can help avoid defects such as incomplete weld fusion.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the radial width a1 of the step end face is (ΦD2-ΦD1) / 2 = (2~3) mm, where ΦD1 is the diameter of the first hole structure and ΦD2 is the diameter of the second hole structure.

[0016] The appropriate dimensions of the stepped end face help to ensure weld quality while avoiding interference between the outer ring flange workpiece and other workpieces.

[0017] In a second aspect, a scribing device is provided, the scribing device being applied to a thrust chamber electroforming assembly as described in any of the implementations of the first aspect above, the scribing device comprising:

[0018] The support frame includes a first support arm and a second support arm. The first support arm is provided with a roller, which is used to roll around an axis on the inner sidewall of the annular connection end to drive the second support arm to move around the axis. The second support arm is located on the side of the outer ring flange workpiece away from the electroformed workpiece body.

[0019] A scribing tip is disposed on the second support arm. The tip of the scribing tip is used to abut against the outer ring flange workpiece. The tip is disposed opposite to the joint position of the annular connection end and the outer ring flange workpiece.

[0020] The device for inspecting electron beam welding deviation of electroformed nickel dissimilar metals is intuitive and convenient to implement, with high accuracy and efficiency, providing a valuable reference for X-ray inspection.

[0021] In conjunction with the second aspect, in some implementations of the second aspect, the second support arm is provided with a slot that extends radially, and the scribing tip is disposed in the slot and is movable relative to the slot.

[0022] This makes it easier to adjust the scribing position of the scribing tip on the outer ring flange workpiece.

[0023] In conjunction with the second aspect, in some implementations of the second aspect, the assembly gap between the slot and the scribing tip is less than 0.05 mm.

[0024] Ensure a tight fit between the slotted and scribing tips to prevent unnecessary movement of the scribing tips.

[0025] In conjunction with the second aspect, in some implementations of the second aspect, the second support arm is provided with a reference position mark, which is disposed opposite to the inner sidewall of the annular connecting end.

[0026] This facilitates the precise positioning of the relative positions of the scribing tip and the joint center.

[0027] Thirdly, a method for inspecting electron beam soldering misalignment is provided, the method being applied to a scribing apparatus as described in any implementation of the second aspect above, the method comprising:

[0028] Using the aforementioned scribing tip, a reference circle, a first scribing circle, and a second scribing circle are scribed on the end face of the main body of the annular connection end away from the electroformed workpiece. The first scribing circle and the second scribing circle are located on both sides of the reference circle, and the radius of the first scribing circle is smaller than the radius of the second scribing circle.

[0029] If the weld leak is located between the first scribe circle and the second scribe circle, it is determined that the weld is not misaligned.

[0030] If the weld leak is located within the first scribed circle and / or outside the second scribed circle, the weld is determined to be off-center.

[0031] The method for inspecting electron beam welding deviation of electroformed nickel dissimilar metals is intuitive and convenient to implement, with high accuracy and efficiency, providing a valuable reference for X-ray inspection.

[0032] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes:

[0033] In the case of continuous weld leaks, the area located inside the first scribing circle and / or outside the second scribing circle is defined as the weld deviation area.

[0034] This allows us to identify areas of weld misalignment and optimize subsequent processes.

[0035] In conjunction with the third aspect, in some implementations of the third aspect, the method further includes:

[0036] In the case of intermittent weld leaks, the weld deviation area is determined by the midpoint of the line connecting the end point of the intermittent weld leak that does not exceed the area between the first and second scribed circles, and the starting point of the next intermittent weld leak that exceeds the area.

[0037] This allows us to identify areas of weld misalignment and optimize subsequent processes.

[0038] Fourthly, an electron beam welding system is provided, the electron beam welding system being applied to a thrust chamber electroforming assembly as described in any of the implementations of the first aspect above, the electron beam welding system comprising:

[0039] A shielding cylinder surrounds the outer periphery of the body of the electroformed workpiece and is disposed on the side of the annular connecting end closer to the body. The magnetic permeability of the shielding cylinder is higher than that of the electroformed workpiece.

[0040] By installing a magnetic field shielding cylinder device during the assembly process, the problem of welding deviation in electron beam welding of dissimilar metals was effectively solved, thus improving the welding quality.

[0041] In conjunction with the fourth aspect, in certain implementations of the fourth aspect, the shielding cylinder satisfies at least one of the following:

[0042] The material of the shielding cylinder is pure iron or L3;

[0043] The thickness of the shielding cylinder is 5-20 mm;

[0044] The height of the shielding cylinder is greater than or equal to 600mm.

[0045] This helps to improve the shielding performance of the shielding cylinder and reduce the degree of electron beam deviation.

[0046] Fifthly, a welding method is provided, said welding method being applied to a thrust chamber electroforming assembly as described in any of the implementations of the first aspect above, said method comprising:

[0047] The product is securely fixed on the turntable, which drives the product to rotate. The radial runout of the outer flange is measured by a dial indicator and then aligned.

[0048] Make a punch at the joint;

[0049] By applying an electron beam, we check whether the welding trajectory coincides with the joint and select the interpolation point.

[0050] Use calipers to measure the distance from the center of the positioning weld to the edge of the outer ring flange workpiece, and check whether the center of the weld crown is at the center of the joint.

[0051] The joint between the electroformed workpiece and the outer ring flange workpiece is welded through using a penetration welding process.

[0052] By employing methods such as pre-welding clamping and alignment, trajectory interpolation programming, weld alignment inspection during the welding process, and the use of penetration welding technology, the problem of weld deviation in electron beam welding of dissimilar metals has been effectively solved, thus improving welding quality. Attached Figure Description

[0053] Figure 1 This is a schematic structural diagram of an electroforming assembly for a thrust chamber.

[0054] Figure 2 for Figure 1 A partially enlarged view of the electroformed thrust chamber assembly shown.

[0055] Figure 3 This is a schematic structural diagram of a thrust chamber electroforming assembly provided in an embodiment of this application.

[0056] Figure 4 for Figure 3 A partially enlarged view of the electroformed thrust chamber assembly shown.

[0057] Figure 5 This is a comparison diagram of flat-head butt joints and lock-bottom butt joints.

[0058] Figure 6 This is a schematic structural diagram of a marking device provided in an embodiment of this application.

[0059] Figure 7 This is a schematic diagram of a method for checking electron beam soldering deviation provided in an embodiment of this application.

[0060] Figure 8This is a schematic structural diagram of an electron beam welding system provided in an embodiment of this application.

[0061] Figure 9 This is a schematic structural diagram of an electron beam welding system provided in an embodiment of this application. Detailed Implementation

[0062] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Figure 1 The area enclosed by the middle dashed line can be referenced. Figure 2 The image shown is a magnified view of the relevant area.

[0063] Figure 1 This is an electroforming assembly for a thrust chamber, comprising an electroformed workpiece 10 and an outer ring flange workpiece 20. The electroformed workpiece 10 may have an axisymmetric structure (the central axis of the electroformed workpiece 10 is hereinafter referred to as the axis), and its shape can be obtained by rotating a cross section. The electroformed workpiece 10 may include an electroformed body and an electroformed outer wall. The electroformed body may be the main body of the electroformed workpiece 10. In some embodiments, the electroformed body may be obtained by spin forming. The electroformed body is surrounded by an electroformed outer wall. The material of the electroformed outer wall is, for example, nickel. The material of the outer ring flange workpiece 20 is, for example, steel.

[0064] One end of the electroformed workpiece 10 is used for welding connection with the outer ring flange workpiece 20. Specifically, the electroformed workpiece 10 may have an annular connecting end 11. The annular connecting end 11 may be located at one end of the electroformed workpiece 10. The annular connecting end 11 may protrude away from the axis. In the axial direction, the size of the annular connecting end 11 is relatively small in proportion to the overall size of the electroformed workpiece 10. The annular connecting end 11 can be integrally connected to the outer ring flange workpiece 20 by electron beam welding. Specifically, the end face of the annular connecting end 11 facing the body of the electroformed workpiece 10 can be used to carry the electron beam pulse. That is, the electron beam can pass through the body of the electroformed workpiece 10 and bombard the joint between the annular connecting end 11 and the outer ring flange workpiece 20.

[0065] When the metal outer wall is electroformed into the electroformed body, a certain amount of magnetism is generated. Measurements show that the magnetism of the electroformed workpiece 10 is 2 × 10⁻⁶. －4 T to 5×10 －4 T. When the charges emitted by the electron gun cathode move in the magnetic field, they are subjected to a magnetic force, namely the Lorentz force, which changes their direction of motion, causing them to deviate. As a result, the beam spot cannot accurately fall on the weld position, such as... Figure 2 As shown.

[0066] In electroforming dissimilar metal welding, poor alignment or magnetic field interference, coupled with the differences in the physical and chemical properties of the two materials during welding, can all cause the electron beam to deflect to one side, resulting in weld misalignment.

[0067] Figure 3 This is a schematic structural diagram of a thrust chamber electroforming assembly provided in an embodiment of this application. Figure 3 The area enclosed by the middle dashed line can be referenced. Figure 4 The image shown is a magnified view of the relevant area.

[0068] The thrust chamber electroforming assembly provided in this application embodiment may include an electroformed workpiece 10 and an outer ring flange workpiece 20. The structure of the electroformed workpiece 10 can be referred to... Figure 1 The structure shown. The outer ring flange workpiece 20 may include a stepped portion whose structure matches the annular connection end 11.

[0069] Specifically, the outer ring flange workpiece 20 may include a first hole structure 21, the wall of which mates with the outer wall of the annular connecting end 11. In some embodiments, the axial height of the first hole structure 21 may be equal to the axial height of the annular connecting end 11.

[0070] The outer ring flange workpiece 20 may further include a second hole structure 22, which may be located on the side of the first hole structure 21 away from the electroformed workpiece 10. The diameter of the second hole structure 22 may be smaller than the diameter of the first hole structure 21. A stepped end face 23 connects the first hole structure 21 and the second hole structure 22, and the first hole structure 21, the second hole structure 22, and the stepped end face 23 may constitute the stepped portion of the outer ring flange workpiece 20. Projected along the axial direction, the annular connecting end 11 and the stepped end face 23 have an intersection area. In some embodiments, the end face of the annular connecting end 11 away from the main body of the electroformed workpiece 10 may overlap the stepped end face 23.

[0071] Combination Figure 5 , Figure 1 The embodiment shown adopts a flat-head connector structure. Figure 3 The illustrated embodiment employs a lock-bottom butt joint (the aforementioned second hole structure 22 and stepped end face 23 can constitute a lock-bottom structure). Due to the differences in thermophysical properties and the influence of magnetic fields on the two sides of the dissimilar metal during electroforming welding, weld misalignment can easily occur, leading to incomplete weld fusion defects at the root of the flat-head butt joint. By using a lock-bottom butt joint, the weld penetrates to the back of the lock bottom, increasing the weld depth and effectively widening the weld width w2 at the bottom of the joint mating surface. Compared to the weld root width w1 of the flat-head butt joint, w2 is greater than w1, effectively avoiding incomplete weld fusion defects.

[0072] In some embodiments, the joint structure is designed as follows: the hole wall height h2 of the second hole structure 22 is 1 / 2h1 (welding depth or thickness of the annular connection end 11 or hole wall height of the first hole structure 21); the hole diameter of the first hole structure 21 is ΦD1, the hole diameter of the second hole structure 22 is ΦD2, and the radial width a1 of the stepped end face 23 is (ΦD2-ΦD1) / 2 = (2~3) mm.

[0073] Figure 6 This is a schematic structural diagram of a scribing device provided in an embodiment of this application. The scribing device can achieve precise scribing for detection. Figure 3 The welding quality of the electroformed thrust chamber assembly shown.

[0074] The marking device may include a support frame 7, which includes a first support arm 71 and a second support arm 72 arranged in parallel. The first support arm 71 is connected to a U-shaped roller frame 2, and the roller frame 2 is equipped with rollers 1. Figure 4 and Figure 6 The roller 1 can roll smoothly and without wobbling on the inner wall of the annular connecting end 11 of the electroformed workpiece 10 around its axis. The second support arm 72 is located on the side of the outer ring flange workpiece 20 away from the electroformed workpiece 10. The second support arm 72 is provided with a scribing tip 6, the tip of which can abut against the outer ring flange workpiece 20. The tip of the scribing tip 6 is aligned with the joint center position 8. When the roller 1 moves on the inner wall of the annular connecting end 11, the scribing tip 6 can scribble on the end face of the outer ring flange workpiece 20 on the side away from the electroformed workpiece 10. In one possible case, the scribing tip 6 can be set vertically relative to the second support arm 72 to facilitate precise adjustment of the scribing position.

[0075] In some embodiments, the second support arm 72 is provided with a slot 73, which can extend in a radial (perpendicular to the axial) direction. The slot 73 is, for example, an elongated elliptical groove. A scribing tip 6 is disposed within the slot 73 and is movable relative to the slot 73 to adjust the scribing position of the scribing tip 6 on the outer ring flange workpiece 20. Figure 6 As shown, the groove width w of the slot 73 and the size of the scribing tip 6 are closely matched, with a gap not exceeding 0.05mm.

[0076] In some embodiments, the scribing tip 6 can be fixed to the second support arm 72 by two symmetrically distributed threaded set screws 5. The direction of the line connecting the two threaded set screws 5 can be perpendicular to the extension direction of the slot 73.

[0077] To accurately position the scribing tip 6, a reference position mark 4 can be provided on the second support arm 72. The reference position mark 4 can correspond to the inner sidewall of the annular connecting end 11 of the electroformed workpiece 10. The reference position mark 4 can be located on the side of the scribing tip 6 closer to the axis, and the radial distance between the reference position mark 4 and the scribing tip 6 is L. This facilitates aligning the tip of the scribing tip 6 with the joint center position 8.

[0078] In some embodiments, the support frame 7 further includes a third support arm 74 connected between the first support arm 71 and the second support arm 72, and a handle 3 is provided on the third support arm 74. This facilitates the operation of the marking device by a worker or robotic arm.

[0079] In one embodiment, during the scribing operation, one hand holds the handle 3 and presses the roller 1 against the electroformed workpiece 10, while the other hand applies downward pressure F to the support frame 7. The roller 1 rotates at a uniform speed v along the inner surface of the electroformed workpiece 10, and the tip of the scribing tip scribing marks a circle of marking lines on the surface of the outer ring flange workpiece 20, with the marking lines aligned with the center of the joint. By adjusting the lateral position of the scribing tip 6 within the groove (loosening the threaded set screw 5 before adjustment and tightening it again after adjustment), multiple parallel circular scribing lines can be drawn on the surface of the outer ring flange workpiece 20.

[0080] like Figure 6 As shown, a reference circle a is drawn on the surface of the outer ring flange workpiece 20 using a scribing device. The diameter of the reference circle a is the same as the hole diameter ΦD1 of the first hole structure 21 mentioned above, satisfying L1 (the distance between the reference circle a and the hole wall of the second hole structure 22 mentioned above) ≈ L2 (i.e., the radial width a1 of the step end face 23 mentioned above), with an error of no more than ±0.05mm. The scribing lines should be clearly visible. In addition, scribing circles b and c are drawn on the inner and outer sides of the reference circle a using scribing tips 6. The reference circle a, scribing circle b, and scribing circle c can be three parallel circles with the same center. The distance between the reference circle a and scribing circle b, and between the reference circle a and scribing circle c, can be equal, for example, 1mm.

[0081] Combination Figure 5 and Figure 7 Assuming the electron beam bombards the front of the outer ring flange workpiece 20, the location of the weld leak in the electron beam weld can be observed on the back of the outer ring flange workpiece 20. The location of the weld leak can be used to initially determine whether there is weld misalignment (further verification of weld misalignment is done via X-ray inspection), providing a basis for deciding whether to perform repair welding. Electron beam weld leaks are classified into two types: continuous leaks and intermittent leaks, and their determination is as follows: Figure 7 As shown.

[0082] (a) If the locations of continuous weld leaks are all distributed near the reference circle a and within the range of scribing circles b and c, then there is no weld deviation area.

[0083] (b) If some continuous weld leaks extend beyond the scribed circle b, the area between the start and end of the extended area is the weld deviation area.

[0084] (c) If some continuous weld leaks extend beyond the marked circle c, then the area between the start and end of the extended area is the weld deviation area.

[0085] (d) If the locations of the intermittent weld leaks are all distributed near the reference circle a and within the range of the scribing circles b and c, then there is no weld deviation area.

[0086] (e) Some intermittent weld defects extend beyond the scribed circle b. The distance between the end point of the previous intermittent weld defect that did not extend beyond the scribed circle and the starting point of the next intermittent weld defect that extended beyond the scribed circle is e1. The distance between the end point of the previous intermittent weld defect that extended beyond the scribed circle and the starting point of the next intermittent weld defect that extended beyond the scribed circle is e2. The midpoint between e1 and e2 is taken, and the range between them is the weld deviation area.

[0087] (f) Some intermittent weld defects extend beyond the scribed circle c. The distance between the end point of the previous intermittent weld defect that did not extend beyond the scribed circle and the starting point of the next intermittent weld defect that extended beyond the scribed circle is e1. The distance between the end point of the previous intermittent weld defect that extended beyond the scribed circle and the starting point of the next intermittent weld defect that extended beyond the scribed circle is e2. The midpoint between e1 and e2 is taken, and the range between them is the weld deviation area.

[0088] This application also provides an electron beam welding system, which may include a shielding cylinder to prevent weld misalignment through magnetic field shielding. The designed magnetic field shielding device is as follows: Figure 8 As shown.

[0089] Combination Figure 3 The thrust chamber electroformed assembly shown has an outer surface formed by electroforming, which possesses a certain magnetic field with a low frequency of magnetic field interference. The axis of the shielding cylinder can be aligned with the axis of the thrust chamber electroformed assembly. The shielding cylinder can be made of a high-permeability material to form a low-resistivity path, thereby confining the magnetic field lines inside the shielding cylinder and preventing them from diffusing into the space outside the shield, thus concentrating most of the magnetic field within the shielding cylinder.

[0090] The higher the magnetic permeability and the greater the thickness of the shielding cylinder, the lower the magnetic reluctance, and the better the magnetic field shielding effect. The magnetic field shielding mechanism mainly relies on the low magnetic reluctance of the high-permeability material, which acts as a shunt for the magnetic flux, thereby greatly weakening the magnetic field inside the shielding cylinder.

[0091] Material selection for shielding cylinder: Iron has a magnetic permeability several thousand times that of air and is a high magnetic permeability material. Through repeated verification, it was found that pure iron or L3 has a more ideal magnetic shielding effect. Therefore, iron material was selected to process the shielding cylinder, and it was finally applied to the welding of electroformed workpiece 10.

[0092] The shielding cylinder, designed according to the structural characteristics of the electroformed workpiece 10, should have an inner diameter that allows it to fall onto the side of the annular connection end 11 closest to the main body of the electroformed workpiece 10 during installation, and close to the root of the main body of the electroformed workpiece 10. This allows for ample path space for the lower electron beam and also provides protection, preventing welding spatter and other debris from entering the bottom groove of the electroformed workpiece 10. The thickness of the shielding cylinder needs to balance the effectiveness of magnetic field shielding (greater thickness, better effect) and avoid obstructing the weld area; the determined thickness is 10mm. The height of the shielding cylinder should cover the entire height of the electroformed workpiece 10 to prevent the electron beam from being affected by the magnetic field as it passes through the entire electroformed workpiece 10; the height of the shielding cylinder is generally not less than 600mm.

[0093] Use of the shielding cylinder: First, place the electroformed workpiece 10 in a demagnetizer for demagnetization. The demagnetizer is a three-phase full-wave rectifier / ultra-low frequency demagnetizer. After demagnetization, use a magnetometer to measure the residual magnetism of the electroformed workpiece 10, which is less than 2 × 10⁻⁶. －4 T. Place the electroformed workpiece 10 on the welding fixture, and after assembly, add a magnetic field shielding cylinder of pure iron or L3 material to the outside of the electroformed workpiece 10, such as... Figure 8 As shown, the residual magnetic field is shielded. The shielding cylinder and tooling are fixedly clamped to prevent movement during workpiece rotation welding. The space along the path of the low-current electron beam should be unobstructed, and at the same time, check for magnetic field interference and whether the beam spot can accurately hit a circle of weld seams. After meeting the conditions, electron beam welding of the electroformed workpiece 10 is performed.

[0094] This application also provides a method for avoiding weld misalignment during the welding process.

[0095] (a) Clamping and Alignment: The product is reliably clamped on the turntable, which rotates the product. The radial runout of the outer flange is measured using a dial indicator and aligned accordingly. The radial runout must be less than 0.2 mm. Figure 9 As shown.

[0096] (b) Make observation marks: punch a sample hole at the joint to facilitate observation of whether the weld is misaligned during the welding process (the electron beam spot will flash when it passes through the sample hole, indicating that the position of the beam spot is consistent with the position of the joint and there is no weld misalignment).

[0097] (c) Trajectory interpolation programming: Using a beam current of 0.5–0.8 mA, check whether the welding trajectory coincides with the joint; and select interpolation points. To ensure interpolation accuracy, at least one interpolation point should be selected for every 15° rotation. By combining workpiece rotation with trajectory interpolation, ensure that the welding trajectory coincides with the joint.

[0098] (d) Small current segmented positioning weld alignment inspection: After the small current segmented welding positioning, use calipers to measure the distance from the center of the positioning weld to the edge of the outer ring flange workpiece 20 (measure at more than 4 points) to check whether the center of the weld crown is in the center of the joint. The deviation should be less than 0.3mm. Otherwise, the interpolation trajectory should be further corrected.

[0099] (e) Lock-through welding: The lock-through welding process is adopted to weld through the back of the lock bottom, increase the weld depth, and effectively widen the weld width at the bottom of the joint mating surface, avoiding defects caused by non-fusion due to weld misalignment.

[0100] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims of the present invention.

Claims

1. A thrust chamber electroforming assembly, characterized in that, include: The electroformed workpiece (10) has an axisymmetric structure and includes an annular connecting end (11) located at one end of the electroformed workpiece (10). The outer ring flange workpiece (20) is connected to the annular connection end (11) by electron beam welding, wherein the electron beam passes through the body of the electroformed workpiece (10) and bombards the joint between the outer ring flange workpiece (20) and the annular connection end (11). The outer ring flange workpiece (20) includes a first hole structure (21), a second hole structure (22), and a stepped end face (23). The stepped end face (23) is connected between the first hole structure (21) and the second hole structure (22). The hole wall of the first hole structure (21) is engaged with the outer wall of the annular connection end (11). The second hole structure (22) is located on the side of the first hole structure (21) away from the main body of the electroformed workpiece (10). The hole diameter of the second hole structure (22) is smaller than that of the first hole structure (21). h2 = (1 / 3~2 / 3)h1, h2 is the hole wall height of the second hole structure (22), and h1 is the welding depth; The radial width a1 of the step end face (23) is (ΦD2-ΦD1) / 2 = (2~3) mm, where ΦD1 is the hole diameter of the first hole structure (21) and ΦD2 is the hole diameter of the second hole structure (22). Using a scribing device, scribing is used to draw a reference circle a on the surface of the outer ring flange workpiece (20). The diameter of the reference circle a is the same as that of the reference circle ΦD1. Scribing circles b and c are drawn on the inner and outer sides of the reference circle a. The reference circle a, scribing circle b and scribing circle c are three parallel circles with the same center. The distance between the reference circle a and scribing circle b, and between the reference circle a and scribing circle c is equal. (a) If the locations of continuous weld leaks are all distributed near the reference circle a and within the range of scribing circles b and c, then there is no weld deviation area. (b) If some continuous weld leaks extend beyond the scribed circle b, then the area between the start and end of the extended area is the weld deviation area. (c) If some continuous weld leaks extend beyond the marked circle c, then the area between the start and end of the extended area is the weld deviation area; (d) If the locations of the intermittent weld leaks are all distributed near the reference circle a and within the range of the scribing circles b and c, then there is no weld deviation area. (e) Some intermittent weld leaks extend beyond the scribing circle b; the distance between the end point of the previous intermittent weld leak that did not extend beyond the scribing circle and the starting point of the next intermittent weld leak that extended beyond the scribing circle is e1, and the distance between the end point of the previous intermittent weld leak that extended beyond the scribing circle and the starting point of the next intermittent weld leak that did not extend beyond the scribing circle is e2; take the midpoint of e1 and e2, and the range between the two is the weld deviation area; (f) Some intermittent weld leaks extend beyond the scribing circle c; the distance between the end point of the previous intermittent weld leak that did not extend beyond the scribing circle and the starting point of the next intermittent weld leak that extended beyond the scribing circle is e1, and the distance between the end point of the previous intermittent weld leak that extended beyond the scribing circle and the starting point of the next intermittent weld leak that did not extend beyond the scribing circle is e2; take the midpoint of e1 and e2, and the range between the two is the weld deviation area.

2. The thrust chamber electroforming assembly according to claim 1, characterized in that, The marking device includes: The support frame (7) includes a first support arm (71) and a second support arm (72). A roller (1) is provided on the first support arm (71). The roller (1) is used to roll around the axis on the inner side wall of the annular connection end (11) to drive the second support arm (72) to move around the axis. The second support arm (72) is located on the side of the outer ring flange workpiece (20) away from the main body of the electroformed workpiece (10). A scribing tip (6) is disposed on the second support arm (72). The tip of the scribing tip (6) is used to abut against the outer ring flange workpiece (20). The tip is disposed opposite to the joint position of the annular connection end (11) and the outer ring flange workpiece (20).

3. The thrust chamber electroforming assembly according to claim 2, characterized in that, The second support arm (72) is provided with a slot (73) that extends radially, and the scribing tip (6) is disposed in the slot (73) and is movable relative to the slot (73).

4. The thrust chamber electroforming assembly according to claim 3, characterized in that, The assembly gap between the slot (73) and the scribing tip (6) is less than 0.05 mm.

5. The thrust chamber electroforming assembly according to any one of claims 2 to 4, characterized in that, The second support arm (72) is provided with a reference position mark (4), which is positioned opposite to the inner wall of the annular connecting end (11).

6. A welding method for a thrust chamber electroforming assembly as described in claim 1, characterized in that, The method includes: The product is securely fixed on the turntable, which drives the product to rotate. The radial runout of the outer flange is measured by a dial indicator and then aligned. Make a punch at the joint to observe whether the weld is off-center during the welding process; By applying an electron beam, check whether the welding trajectory coincides with the joint and select interpolation points, including: using a beam current of 0.5 to 0.8 mA to check whether the welding trajectory coincides with the joint; and selecting interpolation points. To ensure interpolation accuracy, at least one interpolation point is selected for every 15° rotation; and by rotating the workpiece in combination with trajectory interpolation, ensure that the welding trajectory coincides with the joint. Use calipers to measure the distance from the center of the positioning weld to the edge of the outer ring flange workpiece (20), and check whether the center of the weld crown is at the center of the joint; The joint between the electroformed workpiece (10) and the outer ring flange workpiece (20) is welded through using a penetration welding process.

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