Electron beam welding process for super-thick titanium alloy structural parts
By using thickened current-attracting/receiving auxiliary process blocks and current variation processes in the welding of ultra-thick titanium alloy structural components, the problem of weld melting flow forming control was solved, the flow forming of weld metal was improved, weld defects were reduced, and machining accuracy was met.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AVIC BEIJING AERONAUTICAL MFG TECH RES INST
- Filing Date
- 2026-04-16
- Publication Date
- 2026-06-02
AI Technical Summary
In the welding process of ultra-thick titanium alloy structural parts, the existing technology is difficult to control the melting flow and forming of the weld, which leads to poor weld metal flow and defects such as spatter, steam, pits and undercut, affecting the machining accuracy.
A thickened current-inducing/contracting auxiliary process block is adopted, and the continuous variation of the starting, stabilizing, and ending welding current is designed. By forming compensation steps at both ends of the welding zone, the flow of molten metal is restricted, molten metal is replenished, and the molten flow formation of the weld metal is improved.
It effectively reduces weld depressions, pits, and undercut, improves the flow and forming quality of weld metal, and ensures that the welding quality meets the requirements of machining.
Smart Images
Figure CN122125337A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electron beam welding technology, and more specifically to an electron beam welding process for ultra-thick titanium alloy structural components. Background Technology
[0002] With the development of integrated structural design and advanced manufacturing technologies, and given that integral forging and casting cannot meet the requirements for developing large titanium alloy structures, the aerospace, shipbuilding, and nuclear industries urgently need to adopt ultra-thick titanium alloy one-time electron beam welding forming technology. Large aircraft frames and large ship hulls contain numerous straight titanium alloy welds, such as planar splicing welds on frames and longitudinal splicing welds on cylindrical sides, where electron beam welding thicknesses reach 120–160 mm.
[0003] For ultra-thick titanium alloy structures, conventional electron beam welding typically uses a beam-attracting / receiving auxiliary process block with the same thickness as the structure being welded, and employs a beam-attracting / receiving length of 50–60 mm for welding. This can easily lead to problems with the melting and flow formation of the weld metal. 1) Due to the large heat input and deep penetration of the weld, the weld melts, vaporizes, and evaporates, and the molten metal flows, generating a large amount of spatter and steam. As the welding motion progresses, a small amount of molten metal flows and transfers to the beam-guided auxiliary process block in the initial stage, which will cause the molten metal of the weld to burn off. 2) When the weld reaches an ultra-thickness penetration depth, the molten metal of the weld flows backward. Affected by the burning loss of molten metal, a large pit is generated in the area near the flow inlet / outlet, with a depth of 5 to 15 mm. 3) During the welding process, the molten metal in the weld seam flows backward continuously, and the effective weld length will also form a large depression with a depth of not less than 5mm; 4) The low-speed electron beam welding process is used, and due to the influence of molten metal flow and solidification, the undercut depth on both sides of the weld can easily reach 3-5mm. 5) When the weld depression, pit and undercut reach 5mm, the thickness of the ultra-thick titanium alloy structure will be reduced after machining, which will easily cause dimensional deviation.
[0004] Therefore, the inventors have provided an electron beam welding process for ultra-thick titanium alloy structural components. Summary of the Invention
[0005] (1) Technical problems to be solved This invention provides an electron beam welding process for ultra-thick titanium alloy structural components, solving the technical problem of difficulty in controlling the melting flow and forming of welds in ultra-thick titanium alloy structural components.
[0006] (2) Technical solution This invention provides an electron beam welding process for ultra-thick titanium alloy structural components, comprising the following steps: A beam-inducing auxiliary process block and a beam-retracting auxiliary process block are placed at both ends of the welding position of the workpiece to be welded, respectively. The thickness of the beam-inducing auxiliary process block and the beam-retracting auxiliary process block is greater than that of the workpiece to be welded. The corresponding initial welding, stable welding, and final welding are performed sequentially on the upper surface of the beam-inducing auxiliary process block, the welding surface of the workpiece to be welded, and the upper surface of the beam-receiving auxiliary process block. The initial welding current is a continuous current that first increases and then stabilizes, the stable welding current is a constant current, and the final welding current is a continuous current that first increases and then decreases.
[0007] Furthermore, the thickness difference between the beam-inducing auxiliary process block and the beam-receiving auxiliary process block and the workpiece to be welded is 5 to 10 mm.
[0008] Furthermore, the length of the beam-inducing auxiliary process block and the beam-receiving auxiliary process block is 100-200 mm, and the width is 70-150 mm.
[0009] Furthermore, the initial welding length is 0.5 to 1 times the thickness of the workpiece to be welded.
[0010] Furthermore, the welding length at the end of the welding process is 0.6 to 1.2 times the thickness of the workpiece to be welded.
[0011] Furthermore, the final current of the initial welding current is the stable welding current.
[0012] Furthermore, the initial current of the termination welding current is the stable welding current.
[0013] Furthermore, the assembly gaps between the beam-inducing auxiliary process block, the beam-receiving auxiliary process block, and the workpiece to be welded are all less than preset values.
[0014] Furthermore, argon arc welding is used to spot weld and position the assembled beam-leading auxiliary process block, the beam-receiving auxiliary process block, and the non-welding area of the workpiece to be welded.
[0015] Furthermore, the thickness of the workpiece to be welded is greater than 120 mm.
[0016] (3) Beneficial effects In summary, this invention, by designing a thickened current-inducing / current-receiving auxiliary process block, forms compensating steps at both ends of the effective welding zone. This not only restricts the flow and transfer of molten metal from the effective welding zone to the current-inducing auxiliary process block, but also provides sufficient molten metal replenishment to the welding zone during the current-receiving stage, improving the molten flow and forming of the weld metal and compensating for molten metal burn-off. Simultaneously, based on the variation in weld thickness, the welding process lengths for the initial and final stages are designed. The current-inducing welding current, which increases first and then stabilizes, and the current-receiving welding current, which increases first and then decreases, ensure a continuous and stable transition of the welding process, guaranteeing penetration of the effective welding zone and improving the flow and forming quality of the weld molten metal, thereby reducing weld defects such as depressions, pits, and undercut. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic flowchart of an electron beam welding process for an ultra-thick titanium alloy structural component provided in an embodiment of the present invention. Figure 2 This is a top view of the assembly structure of an ultra-thick titanium alloy structural component, a beam-guiding auxiliary process block, and a beam-receiving auxiliary process block provided in an embodiment of the present invention. Figure 3 This is a front view of the assembly structure of an ultra-thick titanium alloy structural component, a beam-inducing auxiliary process block, and a beam-receiving auxiliary process block provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the welding trajectory of an ultra-thick titanium alloy structural component and a beam-inducing auxiliary process block and a beam-receiving auxiliary process block provided in an embodiment of the present invention.
[0019] In the picture: 1-Workpiece to be welded; 2-Welding position; 3-Beam induction auxiliary process block; 4-Beam collection auxiliary process block; 5-Backing plate; 6-Initial welding section; 7-Stable welding section; 8-End welding section. Detailed Implementation
[0020] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. That is, the present invention is not limited to the described embodiments, and any modifications, substitutions and improvements to the parts, components and connection methods are covered without departing from the spirit of the present invention.
[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0022] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0023] This invention provides an electron beam welding process for ultra-thick titanium alloy structural components. (See also...) Figure 1 The method may include the following steps: S100. Place a beam-inducing auxiliary process block and a beam-retracting auxiliary process block at both ends of the welding position of the workpiece to be welded. The thickness of both the beam-inducing auxiliary process block and the beam-retracting auxiliary process block is greater than that of the workpiece to be welded.
[0024] Specifically, to compensate for the loss of molten metal, thickened beam-inducing auxiliary process blocks 3 and beam-retracting auxiliary process blocks 4 were designed at both ends of the welding position 2 of the workpiece 1 to be welded, such as... Figures 2-3 As shown. The beam-inducing auxiliary process block 3, the beam-retracting auxiliary process block 4, and the backing plate 5 are made of the same material as the workpiece 1 to be welded. The beam-inducing auxiliary process block 3 and the beam-retracting auxiliary process block 4 are assembled with the workpiece 1 to be welded and the backing plate 5. The thickness δ1 of the beam-inducing auxiliary process block 3 and the beam-retracting auxiliary process block 4 is 5-10 mm greater than the thickness δ of the workpiece 1 to be welded, that is, δ1=δ+(5-10). Two compensating metal steps are formed at both ends. The compensating steps of the beam-inducing auxiliary process block 3 can prevent the molten metal of the weld from flowing and transferring to the beam-inducing block, thus compensating for the metal loss in the effective welding zone. At the same time, in the welding end stage, the compensating steps of the beam-retracting auxiliary process block 4 melt and flow backward, providing sufficient molten metal replenishment for the effective welding zone. During the welding process, the compensating steps of the beam-inducing auxiliary process block 3 and the beam-retracting auxiliary process block 4 provide conditions for improving the molten flow and forming of the weld metal, compensating for the molten metal burn-off in the effective welding zone, and reducing and eliminating defects such as depressions, pits, and undercuts on the weld surface. For welding ultra-thick titanium alloys, in order to prevent the molten metal of the beam-inducing auxiliary process block 3 and the beam-retracting auxiliary process block 4 from flowing outward, the width and length of the beam-inducing auxiliary process block 3 and the beam-retracting auxiliary process block 4 are designed to be 70-150mm and 100-200mm respectively (to increase the area of the upper end face).
[0025] S200. Sequentially perform the initial welding, stable welding, and final welding on the upper surface of the beam-leading auxiliary process block, the welding surface of the workpiece to be welded, and the upper surface of the beam-receiving auxiliary process block. The initial welding current is a continuous current that first increases and then stabilizes, the stable welding current is a constant current, and the final welding current is a continuous current that first increases and then decreases.
[0026] Specifically, in order to ensure weld penetration and improve the quality of weld melt flow and formation, such as Figure 3 As shown, a starting welding section 6, a stable welding section 7, and a ending welding section 8 were designed. The welding process length of the starting welding section 6 was designed to be (0.5~1)×δ, and it was located on the upper end face of the current-inducing auxiliary process block 3. The welding process length of the ending welding section 7 was designed to be (0.6~1.2)×δ, and it was located on the upper end face of the current-retracting auxiliary process block 4. Through process experiments, the welding current I of the titanium alloy test plate with a thickness of δ during the stable welding stage was obtained. b Based on the process length design of the starting welding segment 6 and the ending welding segment 8, the beam current welding process is designed as 0→I. b +(5~10)mA→I b The beam welding process is designed as I b →I b +5mA→0, where the current in the transition section between the initial welding segment 6 and the stable welding segment 7 needs to be relatively reduced, and the current in the transition section between the stable welding segment 7 and the final welding segment 8 needs to be relatively increased, in order to better complete the stable transition of the three welding stages. The initial welding, stable welding, and final welding are completed on the beam-inducing auxiliary process block 3, welding position 2, and beam-retracting auxiliary process block 4, respectively. Based on the change in welding thickness, the continuous and stable transition from the beam-inducing welding process to the stable welding process and the beam-retracting welding process improves the flow and forming quality of the weld molten metal.
[0027] Example 1 Taking a TC4 titanium alloy workpiece 1 with dimensions of 200×100×160mm as an example, with a welding thickness δ=160mm and a welding length of 200mm, the specific embodiment of electron beam welding is as follows: (1) Design of workpiece to be welded and auxiliary process blocks for beam induction / retraction: The workpiece to be welded 1 is a 200×100×160mm butt test plate. The thickness δ1=165mm of the auxiliary process block 3 for beam induction and the auxiliary process block 4 for beam retraction are designed and prepared, and the width and length are 80mm and 105mm respectively. At the same time, the pad strip 5 is designed and prepared with a size of 410×50×50mm. The surface finish of the workpiece and process blocks is better than 3.2μm. (2) Welding assembly: Assemble the beam-leading auxiliary process block 3, the beam-receiving auxiliary process block 4, and the pad 5 with the workpiece 1 to be welded. The assembly gap and the gap at the welding position 2 are both controlled within 0.1mm. The assembled workpiece is then spot-welded in the non-welding area using argon arc welding and installed into the welding equipment. (3) Electron beam welding: in a vacuum degree better than 5×10 -2 Under Pa conditions, the welding speed was set to 2 mm / s, and welding process parameters of 150 kV acceleration voltage and 360 mA beam current were used for welding. The welding current in the beam initiation stage was 0→365 mA→360 mA, and the welding current in the beam withdrawal stage was 360 mA→365 mA→0. (4) Post-weld flow forming inspection: The surface of the weld is flat after welding, and the maximum value of weld depressions, pits and undercuts is 1.5mm, which meets the design and subsequent processing requirements.
[0028] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.
[0029] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.
Claims
1. An electron beam welding process for ultra-thick titanium alloy structural components, characterized in that, The method includes the following steps: A beam-inducing auxiliary process block and a beam-retracting auxiliary process block are placed at both ends of the welding position of the workpiece to be welded, respectively. The thickness of the beam-inducing auxiliary process block and the beam-retracting auxiliary process block is greater than that of the workpiece to be welded. The corresponding initial welding, stable welding, and final welding are performed sequentially on the upper surface of the beam-inducing auxiliary process block, the welding surface of the workpiece to be welded, and the upper surface of the beam-receiving auxiliary process block. The initial welding current is a continuous current that first increases and then stabilizes, the stable welding current is a constant current, and the final welding current is a continuous current that first increases and then decreases.
2. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, The thickness difference between the beam-leading auxiliary process block and the beam-receiving auxiliary process block and the workpiece to be welded is 5-10 mm.
3. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, The length of the beam-guiding auxiliary process block and the beam-receiving auxiliary process block is 100-200mm, and the width is 70-150mm.
4. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, The initial welding length is 0.5 to 1 times the thickness of the workpiece to be welded.
5. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, The welding length at which the welding ends is 0.6 to 1.2 times the thickness of the workpiece to be welded.
6. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, The final current of the initial welding current is the stable welding current.
7. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, The initial current of the welding termination current is the stable welding current.
8. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, The assembly gaps between the beam guiding auxiliary process block, the beam receiving auxiliary process block and the workpiece to be welded are all less than preset values.
9. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, Argon arc welding is used to spot weld and position the assembled beam-inducing auxiliary process block, the beam-receiving auxiliary process block, and the non-welding area of the workpiece to be welded.
10. The electron beam welding process for ultra-thick titanium alloy structural components according to claim 1, characterized in that, The thickness of the workpiece to be welded is greater than 120mm.