A welding method for a high-temperature alloy cartridge assembly with a large wall thickness difference

Abstract

The application discloses a welding method for a high-temperature alloy casing assembly with large wall thickness difference, and adopts double electron beam synchronous welding, generates an electromagnetic field by using an electromagnetic lens inside a welding machine according to the symmetrical positions of two welds, realizes the double electron beam angle deflection function of the electron beam welding machine, deflects the electron beam flow in real time at a high frequency during the welding travel, makes the electron jump at a high frequency of 0.05-500 kHz between two adjacent welds, and obtains the effect that the electron beam synchronously covers and welds the two side welds. The application solves the problems of weld undercutting and burning, effectively reduces the residual stress of the weld, reduces the welding deformation, improves the welding assembly precision of the high-temperature alloy casing parts, and effectively improves the product quality, the use performance and the failure rate of the high-temperature alloy casing.

Description

Technical Field

[0001] This invention relates to the field of manufacturing process technology for small and medium-sized aero-engine parts, specifically a welding method for high-temperature alloy casing components with large differences in wall thickness. Background Technology

[0002] High-temperature alloy casing structural components are core and critical parts of aero-engines. They enclose the internal rotor and determine the aerodynamic performance of the bypass duct. Therefore, the welding technology of high-temperature alloy casing components is one of the core technologies in aero-engine manufacturing. However, because high-temperature alloy casings are thin-walled annular parts, deformation is a common problem during the welding process of their components, which seriously affects the welding quality of aero-engines, and consequently affects the engine's assembly accuracy, performance, and reliability.

[0003] like Figure 1 As shown, the casing welding assembly of a certain type of engine consists of components such as the inner casing, front vent ring, and rear vent ring, which are mainly welded together by several electron beam welds. The welded areas have poor accessibility, and the material thickness varies greatly. High-temperature alloy plates with a thickness of 0.6 t are welded to high-temperature alloy plates with a thickness of 7 t using fillet welds or lock-bottom butt welds. Thin plates dissipate heat slowly, while thick plates conduct heat quickly, easily causing heat accumulation and deformation in thin plates, making them prone to burn-out. Thick plates conduct heat quickly but do not accumulate enough heat, making weld fusion difficult and resulting in a difficult-to-weld weld.

[0004] Patent CN 110293306 A discloses an electron beam welding method for a combustion chamber casing. This method addresses the characteristics of welding of docking structural parts and the processing technology of combustion chamber casing parts. During the processing of docking parts, a reserved structure is pre-processed on the side wall of the welding end, and a locking bottom structure is pre-processed on the welding end of the main body part. After connecting the docking parts and the main body part through the reserved structure and the locking bottom structure, electron beam welding is performed. After the welding is completed, the reserved structure and the locking bottom structure are cut, thus completing the welding of the combustion chamber casing. However, when using this welding scheme to weld high-temperature alloy casings with large differences in wall thickness, it is necessary to weld one weld first and then weld the other. When welding the first weld, the thin plate heats up quickly, shrinks and deforms, and is stretched, causing the gap of the weld to be welded at the other end to increase. When welding the second weld, it is easy to have defects such as warping, deformation, and burn-through. Summary of the Invention

[0005] This invention addresses the problem of thin plate shrinkage deformation during the initial welding of two adjacent electron beam welds with significant differences in wall thickness in high-temperature alloy casing parts. This leads to localized deformation at the thin plate of the subsequent weld, increasing the gap and causing undercut and burn-out in the later weld. The invention provides a welding method for high-temperature alloy casing components with significant differences in wall thickness.

[0006] The technical solution adopted in this invention is: A welding method for a high-temperature alloy casing assembly with large wall thickness differences includes the following steps: S1 removes oil and oxide film from the high-temperature alloy casing assembly to be welded, wipes it with acetone, and then assembles the assembly to be welded on the welding fixture. The welding assembly includes the high-temperature alloy casing and the thin plate to be welded, and the mating distance between the thin plate and the high-temperature alloy casing is ≤0.1 mm. S2 places the assembled welding fixture into the vacuum chamber of the electron beam welding machine, closes the vacuum chamber door, and waits for the vacuuming process to complete. S3 adjusts and sets the dual electron beam parameters, including the single-sided deflection distance range, single-sided duration, deflection frequency, accelerating voltage, focusing current, and scanning waveform, to ensure that the two beams of the dual electron beam synchronous welding simultaneously cover weld A1 and weld A2. S4 adjusts the electron beam welding parameters and performs the dual electron beam synchronous welding on weld A1 and weld A2. The arc is started from the tack weld position and the welding is completed at the tack weld position after circling the high-temperature alloy casing assembly once.

[0007] Furthermore, the process also includes the following steps: after welding is completed, the sample is removed and the weld surface is subjected to visual inspection, radiographic testing, and dye penetrant testing.

[0008] Furthermore, in the dual electron beam parameters, the single-sided deflection distance range is 0-70 mm, the double-sided deflection range is 0-140 mm, the electron beam deflection frequency is 0.05-500 kHz, the accelerating voltage is 70-150 kV, the focusing current is 1000-3000 mA, and the scanning waveform is circular or elliptical.

[0009] Furthermore, the dual electron beam synchronous welding has a weld seam distance of 15.5 mm, a single-sided duration of 100 μs, an electron beam deflection frequency of 5000 Hz, an accelerating voltage of 120 kV, a focusing current of 1875 mA, and a circular scanning waveform.

[0010] Furthermore, the scanning waveform has a circular scanning radius range of 0-1.2 mm, a frequency of 300-500 Hz, an electron beam current of 0-100 mA, and a welding speed of 0-100 mm / s.

[0011] Furthermore, the scanning waveform has a circular scanning radius of 0.5 mm, a frequency of 500 Hz, an electron beam current of 14 mA, and a welding speed of 20 mm / s.

[0012] Furthermore, the weld widths of welds A1 and A2 are greater than or equal to the width of the overlap between the high-temperature alloy casing and the thin plate to be welded.

[0013] Furthermore, the weld distance between welds A1 and A2 ranges from 3 to 140 mm.

[0014] Furthermore, the thickness difference between the high-temperature alloy casing and the thin plate to be welded is ≥5mm.

[0015] Furthermore, the high-temperature alloy casing and the thin plate to be welded are overlapped, with the thin plate on top and the thick plate on the bottom.

[0016] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention adopts a dual electron beam synchronous welding scheme. The electron beam is deflected by the electromagnetic lens of the electron gun. During the welding process, the electron beam is made to "jump" at high frequency between the two welds, and the two parallel annular welds A1 and A2 are welded simultaneously. The synchronous and same parameter electron beam welding of the welds with approximately geometrically symmetrical cross sections can ensure uniform heat input on both sides of the welds. The welding process involves simultaneous rapid melting and rapid cooling. The overall stress field of the welded structure is symmetrically distributed along the line connecting the midpoints of the two welds. As a result, the deformation trends of the two welds are opposite and symmetrical to each other. Therefore, the mutual influence of deformation between the two welds can be reduced, and the phenomenon of burn-through of the weld after welding deformation can be avoided. This improves the welding and assembly accuracy of the high-temperature alloy casing parts, effectively improves the product quality and performance of the high-temperature alloy casing and reduces the failure rate.

[0017] (2) The present invention has determined the dual electron beam welding process and optimization parameters for high temperature alloy casing welding components. Compared with the existing welding methods, it solves the problems of weld undercut and burn-out, ensures the welding quality of welds with large differences in wall thickness on the high temperature alloy casing, and avoids the rework, scrapping and replacement of large parts, effectively reducing the welding manufacturing cost of high temperature alloy casing.

[0018] (3) The present invention adopts the electron beam deflection dual-beam welding method. The electron beam incident on one side and the surface of the workpiece have a deflection angle. The weld section will also have the same deflection angle. Moreover, the direction of the weld deflection angle is opposite to the direction of one side of the high-temperature alloy casing inner wall. This can effectively reduce and avoid the melting of the high-temperature alloy casing inner wall during the welding process, which is beneficial to maintaining the aerodynamic geometry of the inner wall and improving the processing accuracy.

[0019] (4) Compared with existing welding methods, the present invention adopts dual electron beam synchronous welding, which can simultaneously complete the welding of the two weld seams required for the high-temperature alloy casing assembly. Therefore, while improving the quality of electron beam welding of the high-temperature alloy casing, it also increases welding production efficiency and reduces the use and operating costs of electron beam welding equipment.

[0020] (5) This invention has been applied to the high-temperature alloy casing welding assembly of a certain type of turboshaft engine. In this application, the weld quality has been improved (product qualification rate increased from 50% to 100%), the weld is continuous, the weld formation is good, and the mechanical properties meet the design requirements of the high-temperature alloy casing assembly. The welding method produces stable products and has been applied to welded parts of this model. After long-term engine testing, disassembly inspection showed normal results. Subsequently, multiple batches totaling over one hundred parts have been welded, and all have passed inspection. Attached Figure Description

[0021] Figure 1 A schematic diagram of the weld seam to be welded in a high-temperature alloy casing; Figure 2 A schematic diagram of a dual-beam electron beam welding process; Figure 3 Metallographic diagram of the weld cross-section for a welding method of a high-temperature alloy casing assembly with large wall thickness differences. Detailed Implementation

[0022] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application; however, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below. Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of the invention. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared by existing methods.

[0023] Example 1 Please see Figures 2 to 3 The present invention provides an embodiment of a welding method for a high-temperature alloy casing assembly with large wall thickness differences, comprising the following steps: S1 removes oil stains from the surface of the high-temperature alloy casing assembly to be welded, dries it to remove the oxide film, wipes the surface with acetone, assembles the assembly to be welded on the welding fixture, and performs tack welding. The welding assembly includes the high-temperature alloy casing (7mm thick) and the thin plate to be welded (0.6mm thick). The high-temperature alloy casing and the thin plate to be welded are overlapped, with the thin plate on top and the thick plate on the bottom. The mating distance between the thin plate and the high-temperature alloy casing is ≤0.1mm. S2 places the assembled welding fixture into the vacuum chamber of the electron beam welding machine, closes the vacuum chamber door, and evacuates the vacuum to 1.0 × 10⁻⁶. -4 Mbar, waiting for vacuuming to complete; S3 adjusts and sets the electron beam deflection distance on one side to 15.5 mm, the duration on one side to 100 μs, the deflection frequency to 5000 Hz, the accelerating voltage to 120 kV, the focusing current to 1875 mA, the scanning waveform to be circular, the scanning radius to be 0.5 mm, the frequency to be 500 Hz, the electron beam current to be 14 mA, and the welding speed to be 20 mm / s, to ensure that the two beams of the dual electron beam synchronous welding simultaneously cover weld seam A1 and weld seam A2. S4 adjusts the electron beam welding parameters. The distance between weld seams A1 and A2 is 15.5 mm, and the weld widths of weld seams A1 and A2 are 1.5 mm and 1.5 mm, respectively. The dual electron beam synchronous welding is performed on weld seams A1 and A2. The arc is started from the tack welding position, and the welding is completed at the tack welding position after circling the high-temperature alloy casing assembly once.

[0024] Example 2 Please see Figures 2 to 3 The present invention provides an embodiment of a welding method for a high-temperature alloy casing assembly with large wall thickness differences, comprising the following steps: S1 removes oil stains from the surface of the high-temperature alloy casing assembly to be welded, dries it to remove the oxide film, wipes the surface with acetone, assembles the assembly to be welded on the welding fixture, and performs tack welding. The welding assembly includes the high-temperature alloy casing (7mm thick) and the thin plate to be welded (0.6mm thick). The high-temperature alloy casing and the thin plate to be welded are overlapped, with the thin plate on top and the thick plate on the bottom. The mating distance between the thin plate and the high-temperature alloy casing is ≤0.1mm. S2 places the assembled welding fixture into the vacuum chamber of the electron beam welding machine, closes the vacuum chamber door, evacuates to 1.0×10-4 Mbar, and waits for the evacuation to complete. S3 adjusts and sets the electron beam deflection distance on one side, deflection on both sides, single-side duration of 100 μs, deflection frequency of 5000 Hz, accelerating voltage of 120 kV, focusing current of 1875 mA, scanning waveform circular, scanning radius of 0.5 mm, frequency of 500 Hz, electron beam current of 4.5 mA, and welding speed of 21 mm / s to ensure that the two beams of the dual electron beam synchronous welding simultaneously cover weld A1 and weld A2. S4 adjusts the electron beam welding parameters. The distance between weld seams A1 and A2 is 15.5 mm, and the weld widths of weld seams A1 and A2 are 1.8 mm and 2.2 mm, respectively. The dual electron beam synchronous welding is performed on weld seams A1 and A2. The arc is started from the tack weld position, and the welding is completed at the tack weld position after circling the high-temperature alloy casing assembly once.

[0025] Example 3 Please see Figures 2 to 3The present invention provides an embodiment of a welding method for a high-temperature alloy casing assembly with large wall thickness differences, comprising the following steps: S1 removes oil stains from the surface of the high-temperature alloy casing assembly to be welded, dries it to remove the oxide film, wipes the surface with acetone, assembles the assembly to be welded on the welding fixture, and performs tack welding. The welding assembly includes the high-temperature alloy casing (7mm thick) and the thin plate to be welded (0.6mm thick). The high-temperature alloy casing and the thin plate to be welded are overlapped, with the thin plate on top and the thick plate on the bottom. The mating distance between the thin plate and the high-temperature alloy casing is ≤0.1mm. S2 places the assembled welding fixture into the vacuum chamber of the electron beam welding machine, closes the vacuum chamber door, and evacuates the vacuum to 1.0 × 10⁻⁶. -4 Mbar, waiting for vacuuming to complete; S3 adjusts and sets the electron beam deflection distance on one side to 15.5 mm, the duration on one side to 100 μs, the deflection frequency to 5000 Hz, the accelerating voltage to 120 kV, the focusing current to 1875 mA, the scanning waveform to be circular, the scanning radius to 0.5 mm, the frequency to 500 Hz, the electron beam current to 14 mA, and the welding speed to 20 mm / s, ensuring that the two beams of the dual electron beam synchronous welding simultaneously cover weld seam A1 and weld seam A2; S4 adjusts the electron beam welding parameters, the weld distance range of weld seam A1 and weld seam A2 is 15.5 mm, and performs the dual electron beam synchronous welding on weld seam A1 and weld seam A2, starting the arc from the tack welding position, and completing the welding at the tack welding position after circling the high temperature alloy casing assembly once. After welding is completed, the sample is removed and the weld surface is subjected to visual inspection, radiographic testing and dye penetrant testing. Based on process experiments, under the conditions of a focusing current of 1920mA, an electron beam scanning frequency of 500Hz, and an electron beam deflection frequency of 5000Hz, orthogonal experiments were conducted to verify the effects of electron beam current, accelerating voltage, and welding speed on weld formation. The experimental results are shown in Table 1 below. Table 1 Summary of Welding Parameter Optimization and Results for Weld A

[0026] This invention has been applied to the welding of high-temperature alloy casing assemblies on a certain type of turboshaft engine. The application has improved weld quality (product qualification rate increased from 50% to 100%), resulting in continuous welds, good weld formation, and mechanical properties that meet the design requirements of the high-temperature alloy casing assembly. The welding method produces stable products and has been applied to welded parts of this model. After long-term engine testing, disassembly inspection showed no abnormalities. Subsequent batches totaling over one hundred parts have been welded and have all passed inspection.

[0027] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A welding method for a high-temperature alloy casing assembly with large wall thickness differences, characterized in that, The high-temperature alloy casing and the sheet metal to be welded are joined by overlapping, with the sheet metal to be welded on top. The wall thickness difference between the high-temperature alloy casing and the sheet metal to be welded is ≥5mm. The weld consists of two parallel annular welds, A1 and A2, with a weld distance of 15.5mm between welds A1 and A2. The welding method includes the following steps: S1 removes oil and oxide film from the high-temperature alloy casing assembly to be welded, wipes it with acetone, and then assembles the assembly to be welded on the welding fixture. The welding assembly includes the high-temperature alloy casing and the thin plate to be welded, and the mating distance between the thin plate to be welded and the high-temperature alloy casing is ≤0.1 mm. S2 places the assembled welding fixture into the vacuum chamber of the electron beam welding machine, closes the vacuum chamber door, and waits for the vacuuming process to complete. S3 adjusts and sets the electron beam deflection distance on one side to 15.5 mm, the duration on one side to 100 μs, the deflection frequency to 5000 Hz, the accelerating voltage to 120 kV, the focusing current to 1875 mA, the scanning waveform to be circular, the scanning radius to be 0.5 mm, the frequency to be 500 Hz, the electron beam current to be 14 mA, and the welding speed to be 20 mm / s, to ensure that the two beams of the dual electron beam synchronous welding can simultaneously cover the weld seams A1 and A2 on both sides of the thin plate to be welded; S4 adjusts the electron beam welding parameters and performs the dual electron beam synchronous welding on weld A1 and weld A2. The arc is started from the tack weld position and the welding is completed at the tack weld position after circling the high-temperature alloy casing assembly once.

2. The welding method for a high-temperature alloy casing assembly with large wall thickness differences according to claim 1, characterized in that, It also includes the following steps: after welding is completed, the sample is removed and the weld surface is subjected to visual inspection, radiographic testing and dye penetrant testing.

3. The welding method for a high-temperature alloy casing assembly with large wall thickness differences according to claim 1, characterized in that, The weld widths of welds A1 and A2 are greater than or equal to the width of the overlap between the high-temperature alloy casing and the thin plate to be welded.

Images