A method for electron beam welding of thick titanium alloy plates with filler wire

Abstract

The present invention relates to the field of welding technology, and provides a method for electron beam welding of thick plate titanium alloy with filler wire, which is suitable for electron beam welding of thick plate titanium alloy with a thickness of ≥40 mm, and includes: sequential arrangement of filler wires, press forming of filler wires, wherein the pressed wire is placed in the middle of a butt joint, and can be directly used to realize electron beam welding of thick plate titanium alloys. The method for electron beam welding of thick plate titanium alloy with filler wire described in the present invention effectively solves the problems of the inability to adjust the composition and uneven energy gradient in the direction of penetration existing in conventional electron beam welding without filler wire, through filler wire welding, and realizes precise control of the composition and performance in the thickness direction of the joint by designing that the filler wire is pressed into a thin sheet and placed in the middle of the butt joint along the thickness direction, effectively improving the problems of poor joint strength and toughness matching performance and unevenness caused by energy attenuation, large temperature gradient, and uneven composition in the welding process of thick plate titanium alloys.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to a thick plate titanium alloy filler wire electron beam welding method. Background Art

[0002] In modern industrial manufacturing, high-strength titanium alloy products are widely used in key fields such as aerospace, marine engineering, and chemical equipment due to their excellent mechanical properties and corrosion resistance. As titanium alloy products develop towards larger and more complex shapes, efficient and high-quality welding of thick titanium alloy plates has become a technical problem that needs to be solved urgently.

[0003] At present, arc welding technology, as a traditional method for welding thick titanium alloy plates, can meet the welding penetration requirements of engineering applications to a certain extent through a multi-layer and multi-pass wire welding strategy. However, when the volume size of the structure and the thickness of the weld increase significantly (reaching or exceeding 40 mm), arc welding technology faces many challenges. First, the thermal stress generated during the welding process can easily lead to significant welding deformation, which not only affects the accuracy and appearance of the component, but also may weaken its mechanical properties. Secondly, the multi-layer and multi-pass welding process is complex and inefficient, and it is difficult to meet the needs of modern industry for efficient production. In addition, with the increase of weld thickness, the difficulty of arc welding process to control welding defects such as pores, lack of fusion, and cracks also increases significantly. The existence of these defects seriously reduces the quality and reliability of the welded joint.

[0004] In order to overcome the limitations of arc welding technology in the welding of thick plate titanium alloys, vacuum electron beam welding technology came into being. This technology uses high-energy electron beams as a heat source, which can achieve deep penetration welding of thick plate titanium alloys in one go. It has the advantages of high welding efficiency and small welding deformation, and can greatly improve the progress of structural development in engineering practice. However, conventional electron beam welding does not require filler wire, and the composition of the weld zone cannot be regulated during deep penetration welding, resulting in poor matching of the composition and strength and toughness between the joint area and the parent material area. At the same time, the molten pool is violently disturbed during welding, and there is an energy gradient attenuation in the heat input along the direction of penetration, which makes the structure and performance of the joint in the direction of penetration obvious unevenness, seriously affecting the performance evaluation and assessment of thick plate titanium alloy electron beam welded joints.

[0005] Therefore, the existing technology has many deficiencies in the welding of thick plate titanium alloys. Although arc welding technology can meet certain welding penetration requirements, it has obvious defects in welding deformation, efficiency and defect control; and although vacuum electron beam welding technology has the advantages of high efficiency and low deformation, it cannot achieve the regulation of the composition of the weld zone and the uniformity control of the performance of the weld joint. Therefore, it is urgent to develop a new thick plate titanium alloy welding method to overcome the limitations of the existing technology and achieve efficient and high-quality welding of thick plate titanium alloys. Summary of the invention

[0006] In view of this, the present invention aims to propose a method for thick plate titanium alloy filler wire electron beam welding, which adopts the method of adjusting the filler wire composition and filling size to achieve stable and reliable welding of thick plate titanium alloy, improve the problems of joint strength and toughness matching and poor performance uniformity in the thickness direction, and improve the efficiency and welding quality of thick plate titanium alloy electron beam welding. This method also provides a solution for performance regulation of other types of thick plate metal electron beam welding.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A thick plate titanium alloy filler wire electron beam welding method, suitable for thick plate titanium alloy electron beam welding with a thickness of ≥40 mm, comprising the following steps:

[0009] S1: Press the welding wire to be filled into a thin sheet through a tool;

[0010] S2: After cleaning the wire sheet pressed into thin sheets, place it in the middle of the cleaned weld of the butt joint along the thickness direction of the joint;

[0011] S3: Assemble and fix the workpiece to be welded, wire material and fixture according to welding requirements, install arc starting and arc ending blocks at both ends of the weld, and use TIG welding to fix by spot welding;

[0012] S4: Pre-spot welding, sealing welding and formal welding of titanium alloy filler wire welds are performed by electron beam welding according to set process parameters, and the welding depth is increased in sequence until the required welding penetration depth and width are reached, so that the filler wire components are well fused with the base material;

[0013] S5: After welding is completed, the vacuum is removed, the arc starting block is removed, the spatter on the weld surface is cleaned, and the welding is completed.

[0014] Furthermore, in step S1, a tooling including a male mold and a female mold is provided, wherein the female mold is used to place the wire and the male mold is used to apply pressure, and the wire is pressed into a thin sheet by a pressure welding method.

[0015] Furthermore, in step S2, at least two components of wire materials pressed into thin sheets are arranged along the thickness direction of the butt joint.

[0016] Furthermore, along the thickness direction of the butt joint weld, the wires with different compositions show a gradient change, and the strength and toughness of the wires in the middle are higher than those of the filling wires at the surface and root.

[0017] Furthermore, along the thickness direction of the butt joint weld, the filler wire at the root and the filler wire at the surface are made of the same material or different materials.

[0018] Furthermore, along the thickness direction of the butt joint weld, the range of the filler wire at the surface layer along the thickness direction is 3mm~8mm, and the range of the filler wire at the root along the thickness direction is 6mm~15mm.

[0019] Furthermore, in step S2, the pressed thin wire sheet is placed in the middle of the thick plate butt joint, and the maximum assembly gap and misalignment are adjusted to ≤0.30 mm.

[0020] Furthermore, the wire thickness of the welding wire to be filled is φ. In step S1, the wire pressing thickness is controlled to be 0.4φ~0.75φ after being pressed and connected by tooling.

[0021] Furthermore, before step S1, the following steps are also included:

[0022] ST1: Precision machining the symmetrical surface of the weld groove of the workpiece to be welded according to the design drawing;

[0023] ST2: Clean the surface of the workpiece to be welded and remove oil stains.

[0024] Furthermore, it can be applied to the welding of thick plate aluminum alloy, alloy steel, high-temperature alloy, and dissimilar metal structures.

[0025] Compared with the prior art, the thick plate titanium alloy wire-filled electron beam welding method of the present invention has the following advantages:

[0026] (1) The method for thick plate titanium alloy electron beam welding with filler wire described in the present invention effectively solves the problems of the inability to adjust the composition and uneven energy gradient in the direction of penetration in conventional electron beam welding without filler wire by welding with filler wire. By designing that the filler wire is pressed into a thin sheet and placed in the middle of the joint along the thickness direction, precise control of the composition and performance of the joint in the thickness direction is achieved, effectively improving the problems of poor joint strength and toughness matching performance and unevenness caused by energy attenuation, large temperature gradient, and uneven composition in the thick plate titanium alloy welding process.

[0027] (2) The method for electron beam welding of thick titanium alloy plates with filler wire described in the present invention is simple to operate and can complete electron beam welding of longer welds, large cross-sections, and different positions at one time. It helps to reduce the difficulty of process development for performance regulation of electron beam welding of thick titanium alloy plates and improve the quality of weld joint evaluation. It can be widely used in welding applications of thick aluminum alloy plates, alloy steels, high-temperature alloys, and dissimilar metal structures, and improve the reliability and stability of electron beam welding of thick plates with complex structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 This is a schematic diagram of a tooling structure for pressing a wire material into a thin sheet according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the wire material pressed into a thin sheet filled between the workpieces to be welded according to an embodiment of the present invention;

[0031] Description of reference numerals:

[0032] Punch 1, die 2, butt joint 3, wire material 4, limit bolt 5. DETAILED DESCRIPTION

[0033] In order to make the technical means, objectives and effects of the present invention easy to understand, the embodiments of the present invention are described in detail below with reference to specific drawings.

[0034] It should be noted that all the terms used in the present invention for directional and positional indications, such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside", "top", "lower", "lateral", "longitudinal", "center", etc., are only used to explain the relative positional relationship and connection status between the components in a certain state (as shown in the accompanying drawings), and are only for the convenience of describing the present invention, rather than requiring the present invention to be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0035] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0037] Titanium alloy materials have the advantages of light weight, high strength, corrosion resistance, and good weldability, and are widely used in large and complex structures. With the urgent need for high-quality and efficient welding of thick plate titanium alloys, vacuum electron beam welding is extremely suitable for deep fusion welding of thick plate titanium alloys due to its high energy density and the absence of multi-layer and multi-pass filler wires. However, due to the obvious energy attenuation in the direction of penetration of thick plate electron beam welding, the complex keyhole effect of the molten pool, and the large differences in uniformity of structure and performance in the thickness direction, the composition of the weld zone cannot be adjusted without filler welding materials, resulting in uneven strength and toughness matching of thick plate titanium alloy joints.

[0038] like Figure 1~2 As shown, the present invention mainly solves the welding problem of matching the strength and toughness of thick plate titanium alloy electron beam welding, designs a thick plate titanium alloy filler wire electron beam welding method, which is suitable for thick plate titanium alloy electron beam welding with a thickness of ≥40mm, and includes the following steps:

[0039] S1: Press the welding wire to be filled into a thin sheet through a tool;

[0040] S2: After cleaning the wire sheet pressed into thin sheets, place it in the middle of the cleaned weld of the butt joint along the thickness direction of the joint;

[0041] S3: Assemble and fix the workpiece to be welded, wire material and fixture according to welding requirements, install arc starting and arc ending blocks at both ends of the weld, and use TIG welding to fix by spot welding;

[0042] S4: Pre-spot welding, sealing welding and formal welding of titanium alloy filler wire welds are performed by electron beam welding according to set process parameters, and the welding depth is increased in sequence until the required welding penetration depth and width are reached, so that the filler wire components are well fused with the base material;

[0043] S5: After welding is completed, the vacuum is removed, the arc starting block is removed, the spatter on the weld surface is cleaned, and the welding is completed.

[0044] The invention discloses a method for electron beam welding of thick plate titanium alloy with filler wire. Aiming at the problems that conventional electron beam welding of thick plate titanium alloy has no filler wire composition control and energy gradient is uneven in the direction of penetration depth during welding, filler wire welding is performed in the thickness direction of the joint, and the filler wire is pressed into a thin sheet by using a special tooling to facilitate efficient clamping and filling, and the pressed and connected wire material 4 is cleaned and placed in the middle of the weld of the butt joint after cleaning to form a precision assembly joint, and the other reverse side is also convenient for controlling the composition of the joint welding wire to achieve regulation of composition and performance, and then the workpiece, wire material and tooling are assembled and fixed according to welding requirements, and spot welded and fixed by TIG welding, and then, pre-spot welding, sealing welding and formal welding are performed according to set parameters by using an electron beam welding method, and the welding depth is gradually increased until the required welding penetration depth and width are reached, so as to ensure that the filler wire composition is well fused with the base material, thereby compensating for the energy attenuation and composition unevenness in the direction of penetration depth during electron beam welding by filler wire welding, and improving the strength and toughness matching of the welded joint.

[0045] The thick plate titanium alloy filler wire electron beam welding method described in the present invention effectively solves the problems of the inability to adjust the composition and uneven energy gradient in the direction of penetration in conventional electron beam welding without a filler wire through filler wire welding. By designing that the filler wire is pressed into a thin sheet and placed in the middle of the joint along the thickness direction, precise regulation of the composition and performance of the joint in the thickness direction is achieved, effectively improving the problems of poor joint strength and toughness matching performance and unevenness caused by energy attenuation, large temperature gradient, uneven composition and the like in the thick plate titanium alloy welding process.

[0046] More importantly, the thick plate titanium alloy wire-filled electron beam welding method described in the present application uses a simple and easy joint filling wire design method, reduces welding defects, improves weld quality, and can provide a variety of component design options for future performance regulation of ultra-thick plate alloy electron beam deep penetration welding, meeting the high performance requirements of large and complex structures for welded joints.

[0047] As a preferred example of the present application, in step S1, a tooling including a male mold and a female mold is set up, wherein the groove is used to place the wire material, and the male mold is used to apply pressure, and the wire material is pressed into a thin sheet by a pressure welding method.

[0048] The setting introduces a tooling including a punch 1 and a die 2, and uses a pressure welding method to press the wire into a thin sheet. This pretreatment process makes the filler wire material more compact and continuous, reduces the difficulty of operation and fusion problems caused by the dispersion of the wire during welding, and at the same time, the prefabricated filler wire sheet can better fit the parent material, improving the composition uniformity and mechanical properties of the welded joint. In addition, the method also simplifies the preparation steps before welding, significantly improves the efficiency and convenience of clamping and filling, shortens the overall welding cycle, and reduces production costs. Preferably, a limit bolt 5 is set on the punch 1, which can adjust the pressing accuracy by 0.1 mm.

[0049] As a preferred example of the present application, in step S2, at least two components of wire materials pressed into thin sheets are arranged along the thickness direction of the butt joint.

[0050] This setting further optimizes the design of the wire material for welding the titanium alloy back plate. The wire material 4 filled in the butt joint is a titanium alloy grade welding wire that matches the parent material of the butt joint 3, such as TC3, TC4, TA1, TA2 and other welding wires. Considering factors such as chemical composition compatibility, mechanical property matching, thermal crack sensitivity, etc., wire materials 4 with suitable composition designs are selected and pressed into thin sheets, and then stacked and filled in the weld in the thickness direction of the joint to form a multi-layer and multi-component filling wire structure. These multi-layer and multi-component filling wire structures can melt layer by layer as the electron beam penetrates deeper, thereby achieving adjustment of the composition of different areas of the weld, solving the problem of the inability to control the composition in traditional electron beam welding without filling wire, ensuring the coordination of the composition uniformity and mechanical properties of the weld joint, achieving precise control of the composition of the weld joint, and effectively solving the problem of large composition difference between the weld area and the parent material area and poor strength and toughness matching in traditional welding methods, further improving the strength and toughness matching of the weld joint, and providing a new technical approach for high-quality welding of thick plate titanium alloy structural parts.

[0051] As a preferred example of the present application, along the thickness direction of the butt joint weld, the wires of different compositions change in a gradient, and the strength and toughness of the wires in the middle are higher than the strength and toughness of the filling wires in the surface and root. As a preferred example of the present application, along the thickness direction of the butt joint weld, the filling wires in the root and the filling wires in the surface can be made of the same material or different materials, the filling wires in the surface are set in a range of 3mm to 8mm along the thickness direction, and the filling wires in the root are set in a range of 6mm to 15mm along the thickness direction.

[0052] This setting further designs a gradient change for the thin wire filled in the joint weld. In the thickness direction of the weld, by carefully selecting and arranging wires of different materials and properties, a gradient structure with a gradual transition from the surface to the root is formed, making the performance of the weld in the thickness direction more uniform and continuous, avoiding performance degradation due to sudden material changes, optimizing the material properties of each part of the weld, reducing defects and residual stresses in the welding process, and achieving the purpose of improving the overall performance of the welded joint.

[0053] As a preferred example of the present application, in step S2, the pressed thin wire is placed in the middle of the thick plate butt joint, and the maximum assembly gap and misalignment are adjusted to ≤0.30mm. Preferably, the maximum assembly gap and misalignment are adjusted to ≤0.15mm. By accurately placing the pressed thin wire in the middle of the thick plate butt joint, and strictly controlling the assembly gap and misalignment within 0.3 mm, high-precision assembly is achieved in the electron beam wire welding of thick plate titanium alloy, which significantly improves the quality of the welded joint and reduces welding defects such as pores and unfused joints. At the same time, the tight assembly also improves the mechanical properties of the welded joint, including strength and toughness, so that the welded joint performs well in both load-bearing capacity and service life.

[0054] As a preferred example of the present application, the wire thickness of the welding wire to be filled is φ. In step S1, the wire pressing thickness is controlled to be 0.4φ~0.75φ after being pressed and connected by the tooling. This setting accurately controls the pressing thickness of the wire through the pressure welding method, effectively enhances the fusion effect between the welding wires, reduces the occurrence of welding defects such as pores and unfused phenomena, thereby greatly improving the mechanical properties and durability of the welded joint. At the same time, through the thickness control of the above-mentioned pressing process, the contact area between the materials is enhanced, the heat conduction and melting process during welding are accelerated, the welding cycle is shortened, the production efficiency is improved, the welding quality is more stable, and it is helpful to realize the standardized production of welding products, reduce the defective rate, and save costs.

[0055] As a preferred example of the present application, before step S1, the following steps are also included:

[0056] ST1: Precision machining the symmetrical surface of the weld groove of the workpiece to be welded according to the design drawing;

[0057] ST2: Clean the surface of the workpiece to be welded and remove oil stains.

[0058] This setting further increases the pre-welding preparation work by adding the ST1 step, which is to perform symmetrical surface precision machining on the weld groove of the workpiece to be welded. The purpose of this step is to ensure that the shape and size of the weld groove are completely consistent with the design drawing, thereby providing precise positioning and reference for subsequent welding work; then, in the ST2 step, the surface of the workpiece to be welded is cleaned to remove impurities such as oil stains. The purpose of this step is to improve the welding quality, because impurities such as oil stains will affect the fusion and forming of the weld, and may even cause welding defects, thereby ensuring that the workpiece state before welding is optimal, laying a solid foundation for subsequent welding work.

[0059] As a preferred example of the present application, in step ST2, the surface to be welded is cleaned by mechanical polishing, and then cleaned with acetone or alcohol solvent to remove oil stains.

[0060] This setting further optimizes and limits the surface cleaning of the workpiece to be welded, and uses mechanical polishing to process the surface to be welded, which not only removes the rough layer and oxides on the surface, but also improves the surface flatness, which helps to evenly spread the molten pool during welding and reduces the occurrence of welding defects. At the same time, cleaning with acetone or alcohol solvents completely removes organic matter such as oil stains, avoiding the adverse effects of these impurities on the quality of the weld during the welding process, improving the quality and reliability of the welded joint, reducing the incidence of welding defects, and providing a more solid guarantee for subsequent manufacturing and processing, while also improving the overall performance and appearance quality of the product.

[0061] The thick plate titanium alloy wire-filled electron beam welding method described in the present invention is designed and developed for thick plate alloys (>40 mm). A wire-filled electron beam welding method capable of quickly adjusting the wire size and composition is firstly prefabricated by pressure welding, and pressed to achieve reliable connection between wire diameters. Then, the wire is placed in the middle of the butt joint, and the thick plate titanium alloy wire-filled weld is welded by the electron beam welding method to achieve effective penetration and quality control.

[0062] Compared with the prior art, the thick plate titanium alloy filler wire electron beam welding method of the present invention has the following significant advantages:

[0063] 1. Provide a design method that is different from traditional electron beam welding joints, which can quickly perform electron beam wire welding and is simple and feasible;

[0064] 2. This invention can overcome the deficiency of conventional electron beam welding that the composition of the weld zone cannot be controlled in thick plate titanium alloy welding, and at the same time improve the mechanical uniformity of thick plate titanium alloy welded joints;

[0065] 3. The filler wire composition of the thick plate titanium alloy combined welding joint designed by the present invention is not limited by the capabilities of the welding method itself, and the operation is simple. It can complete electron beam welding of longer welds, large cross-sections, and different positions at one time, which helps to reduce the difficulty of process development for performance regulation of thick plate titanium alloy electron beam welding and improve the quality of welding joint evaluation.

[0066] The thick plate titanium alloy wire-filled electron beam welding method described in the present invention is designed for thick plate titanium alloy (≥40mm). The method of pre-filling wire in the thickness direction and then electron beam deep melting welding is used to adjust the composition of the joint weld zone and weld full thickness welding, so as to obtain a thick plate titanium alloy electron beam welded joint with matching strength and toughness between the joint and the parent material and uniform structure and performance in the thickness direction. The improvement ideas of the thick plate titanium alloy wire-filled electron beam welding method described in the present invention mainly include: sequential arrangement of the wires and pressing and forming of the wires, wherein the pressed wire is placed in the middle of the butt joint, which can be directly used to realize the electron beam welding of the thick plate titanium alloy, and the thick plate titanium alloy is formed and the performance is regulated by optimizing the wire-filling design and welding process, so as to effectively realize the reliable welding of the thick plate titanium alloy. The method has important guiding significance for the welding of thick plate titanium alloy structures, and can be extended to the welding applications of thick plate aluminum alloys, alloy steels, high-temperature alloys, and dissimilar metal structures, so as to improve the reliability and stability of electron beam welding of complex structure thick plates.

[0067] Example

[0068] The present invention provides a method for electron beam welding of thick plate titanium alloy with filler wire, and the specific process steps are as follows: After setting the groove processing on the butt surfaces of two TC4ELI titanium alloy workpieces to be welded (δ80×300×500mm), the surface is mechanically treated, and then ultrasonic cleaning is performed with acetone and alcohol solvent to remove oil stains. TC4 and TC3 welding wires with a diameter of φ2.0mm are arranged in a process sequence and pressed and fixed by a vacuum pressure welding method. The pressed welding wires are taken out and placed in the middle of the thick plate butt joint, and the assembly gap and misalignment are adjusted to ≤0.15mm, and spot welding is performed by TIG welding. The workpieces to be welded are assembled on a fixed tooling and fixed, and the welding procedures are set in sequence according to the process parameters according to the electron beam spot welding, sealing welding, and formal welding processes to complete the electron beam welding with filler wire; after welding is completed, the weld surface is cooled to room temperature and cleaned, and the entire welding work is completed.

[0069] The welding wire process arrangement sequence is: TC3 welding wire for the surface layer of 5mm in thickness direction, TC4 welding wire for the middle position, and TC3 welding wire for the root 10mm. TC4ELI and TC3 welding wires with a diameter of φ2.0mm are pressed and connected in sequence, and the wire pressing thickness is controlled to be 1.2~1.5mm. The process parameters of electron beam welding of titanium alloy butt joints are welding power 32KW and welding speed 150~200mm / min.

[0070] After the test, the tensile performance test of the conventional electron beam welded joint in the thickness direction showed that the difference in tensile strength between the upper and lower layers was >30MPa, which gradually increased from top to bottom, and the difference in impact toughness between the upper and lower layers was >30Pa, which gradually decreased from top to bottom. Conventional electron beam welding has no filler wire, and the heat input decreases from top to bottom along the thickness of the joint. The cooling rate of the lower layer is the fastest, resulting in more needle-shaped martensite in the weld zone of the lower layer of the joint, so the joint strength of the lower layer is higher and the impact toughness is lower. This not only affects the strength and toughness matching of the joint, but also increases the unevenness of the joint performance.

[0071] Through electron beam wire welding, the composition of the weld center and the welding thickness direction is adjusted, mainly because the Al content of the filler metal is slightly different. The chemical composition of the TC3 wire is 5% Al, and the chemical composition of the TC4 wire is 6%. The strength of TC3 is lower than that of TC4, and the plasticity and toughness are better. Adding TC3 welding wire in the lower weld area can improve the proportion of TC4ELI joint molten pool elements during welding, so that the organization changes when the cooling rate is fast, the joint strength is slightly reduced, and the impact toughness is improved. The tensile performance test of the electron beam wire joint in the thickness direction shows that the difference is less than 10MPa, and the impact toughness value of the weld area is within the range of ±5J of the average value. The strength and toughness matching of the thick plate titanium alloy electron beam welding joint is more appropriate, and the uniformity of the mechanical properties in the thickness direction is controlled.

[0072] The present invention provides a thick plate titanium alloy electron beam wire-filling welding method for specific joint performance requirements. The non-destructive testing of the welded joint meets the NB / T47013 Level I qualification, effectively improving the strength and toughness matching and performance uniformity of the welded joint and the parent material, and improving the quality of the titanium alloy electron beam welding weld.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for electron beam welding of thick titanium alloy plates with filler wire, characterized in that: Applicable to electron beam welding of titanium alloy thick plates ≥40mm thick, including the following steps: S1: Press the welding wire to be filled into a thin sheet through a tooling; In step S1, a tooling including a male mold and a female mold is provided, wherein the female mold is used to place the wire and the male mold is used to apply pressure, and the wire is pressed into a thin sheet by a pressure welding method; The wire thickness of the welding wire to be filled is φ. In step S1, the wire pressing thickness is controlled to be 0.4φ~0.75φ after being pressed and connected by the tooling; S2: After cleaning the wire sheet pressed into thin sheets, place it in the middle of the cleaned weld of the butt joint along the thickness direction of the joint; In step S2, at least two components of wire materials pressed into thin sheets are arranged along the thickness direction of the butt joint; The wire material filled in the butt joint is a titanium alloy grade welding wire that matches the base material of the butt joint. The wire materials with various components are selected to be compatible and pressed into thin sheets, and then stacked and filled in the weld in the thickness direction of the joint to form a multi-layer and multi-component wire filling structure. Along the thickness direction of the butt joint weld, the wires with different compositions change in a gradient, and the strength and toughness of the wires in the middle are higher than those of the filling wires at the surface and root. S3: Assemble and fix the workpiece to be welded, wire material and fixture according to welding requirements, install arc starting and arc ending blocks at both ends of the weld, and use TIG welding to fix by spot welding; S4: Pre-spot welding, sealing welding and formal welding of titanium alloy filler wire welds are performed by electron beam welding according to set process parameters, and the welding depth is increased in sequence until the required welding penetration depth and width are reached, so that the filler wire components are well fused with the base material; S5: After welding is completed, the vacuum is removed, the arc starting block is removed, the spatter on the weld surface is cleaned, and the welding is completed.

2. The thick plate titanium alloy filler wire electron beam welding method according to claim 1, characterized in that: Along the thickness direction of the butt joint weld, the filler wire at the root and the filler wire at the surface are made of the same material or different materials.

3. The thick plate titanium alloy filler wire electron beam welding method according to claim 1 or 2, characterized in that: Along the thickness direction of the butt joint weld, the range of the filler wire at the surface layer along the thickness direction is 3mm~8mm, and the range of the filler wire at the root along the thickness direction is 6mm~15mm.

4. The thick plate titanium alloy filler wire electron beam welding method according to claim 1, characterized in that: In step S2, the pressed thin wire sheet is placed in the middle of the thick plate butt joint, and the maximum assembly gap and misalignment are adjusted to ≤0.30 mm.

5. The thick plate titanium alloy filler wire electron beam welding method according to claim 1, characterized in that: Before step S1, the method further includes the following steps: ST1: Precision machining the symmetrical surface of the weld groove of the workpiece to be welded according to the design drawing; ST2: Clean the surface of the workpiece to be welded and remove oil stains.

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