Laser welding method for horn-shaped joint

Abstract

The invention provides a laser welding method for a trumpet-shaped joint, which relates to the field of metal material processing and comprises the following steps: S1, two to-be-welded steel plates form a trumpet-shaped to-be-welded welded junction, and at least one to-be-welded steel plate is trumpet-shaped; s2, laser wire filling welding is adopted for welding, and the welding wire adding position is located at the horn mouth; the distance between the top end of the welding wire and the two steel plates to be welded is 0-1mm; the incident angle of the laser beam is within + / -10 degrees of the angular bisector of the horn-shaped welding opening; the focus of the laser beam is positioned on the axis of the top end of the welding wire and is 0-10mm away from the axis of the And the feeding speed of the welding wire is 2-5 times of the welding speed. By means of the laser filler wire welding mode, laser welding of the horn-shaped welded junction is achieved, weld joint transition is uniform, the surface is in an arc shape, and the defects of undercut and the like are avoided. Defect-free welding of a horn-shaped welded junction is achieved, and surface transition of a weld joint is uniform. The welding process is simple and easy to operate.

Description

Technical Field

[0001] The invention relates to the field of metal material processing, and in particular to a laser welding method for a trumpet-shaped joint. Background Art

[0002] With the popularity of laser welding, laser welding is increasingly being used in various fields. In automotive slide rails, chassis and seat structures, trumpet-shaped welds are also laser welded, but there are welding problems such as undercutting of the weld joint causing thinning of the steel plate, low joint strength, and incomplete welds. Laser wire welding is an important means to achieve full laser welds, and this process is currently widely used in flat plate welding. Due to the unique shape of the trumpet weld, ordinary laser wire welding cannot obtain a weld joint with a concave arc surface and no undercut at the joint.

[0003] Patent CN105290601A "A method for welding high-energy beam fillet weld joints" solves the welding problem of vertical fillet welds by welding twice. The biggest drawback of this patent is that it requires two weldings, which has low production efficiency, and the welding angles of the two weldings are strictly limited and cannot be freely applied. Patent CN110666290A "A method for full penetration welding of U-shaped rib fillet welds" mainly involves the welding of bridge steel. The patent uses argon-rich gas shielded welding to perform inner and outer fillet welds respectively to achieve full penetration, and the weld joints are free of slag inclusions, undercuts or weld leaks, ensuring that the weld appearance is well formed. This patent mainly uses consumable gas shielded welding, and its target is the welding of medium and thick steel plates such as bridge steel.

[0004] The above patents are all developed for different forms of fillet welds, but the welding process is complicated and requires two passes of welding. The welding forms are different, and the welding forms of the two patents are both "T"-shaped fillet welds.

[0005] The present invention proposes a laser wire-filling welding solution for trumpet-shaped welds, thereby obtaining a weld joint with a concave arc surface, no undercut, and low stress concentration on the joint. Summary of the invention

[0006] According to the above technical problems of the prior art, a method for laser welding of a trumpet-shaped weld is provided. The invention realizes laser welding of a trumpet-shaped weld by laser wire welding, and the weld transition is uniform, the surface is arc-shaped, and there is no defect such as undercut.

[0007] The technical means adopted by the present invention are as follows:

[0008] A laser welding method for a trumpet-shaped joint comprises the following steps:

[0009] S1. Two steel plates to be welded form a trumpet-shaped weld, wherein at least one of the steel plates to be welded is trumpet-shaped;

[0010] S2. Laser wire-filling welding is used for welding, and the wire is added at the bell mouth;

[0011] S21. The distance between the top of the welding wire and the two steel plates to be welded is 0-1 mm;

[0012] S22, the incident angle of the laser beam is within ±10° of the bisector of the trumpet-shaped weld angle;

[0013] S23, the laser beam focus is located on the axis of the top end of the welding wire, 0 to 10 mm away from the axis of the top end of the welding wire;

[0014] S24. The wire feeding speed is 2 to 5 times the welding speed.

[0015] Furthermore, the diameter of the welding wire in S2 is 0.8 mm to 1.2 mm.

[0016] Furthermore, the cross-section of the welding wire is circular.

[0017] Furthermore, in S21, the top end of the welding wire is within the focal range of the laser beam.

[0018] Furthermore, welding is completed when the upper surface of the weld is tangential to the steel plate and presents a concave state.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The present invention realizes the laser welding of the trumpet-shaped weld by laser wire-filling welding, and the weld transition is uniform, the surface is arc-shaped, and there is no defect such as undercut.

[0021] The invention realizes defect-free welding of trumpet-shaped welds, and the weld surface transition is uniform. The welding process is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 The figure is a flow chart of the welding method of the present invention.

[0024] Figure 2 It is a schematic diagram of welding in the present invention.

[0025] Figure 3Schematic diagram of a good weld in the present invention.

[0026] Figure 4 It is a schematic diagram of weld undercut in the present invention.

[0027] Figure 5 It is a schematic diagram of a weld with a large amount of welding wire filling in the present invention.

[0028] In the figure: 1. welding steel plate; 2. laser beam; 3. welding wire; 4. undercut. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0033] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0034] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0035] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0036] like Figure 1-5 As shown, the present invention provides a laser welding method for a trumpet-shaped joint, comprising the following steps:

[0037] S1. A trumpet-shaped weld consists of two steel plates 1 to be welded, at least one of which is in the shape of a trumpet.

[0038] S2. Laser wire welding is used for welding. The cross section of the welding wire 3 is circular. The welding wire 3 is added at the bell mouth. The top end of the welding wire 3 is kept at a distance of 0 to 1 mm from the two steel plates to be welded, and the top end of the welding wire 3 is within the laser focus range.

[0039] The incident angle of the laser beam 2 is within ±10° of the bisector of the horn angle, and the focus of the laser beam 2 is located on the axis of the top end of the welding wire 3, and the distance from the axis of the top end of the welding wire 3 (defocus amount) is 0 to 10 mm;

[0040] The wire feeding speed V1 is 2 to 5 times the welding speed V2.

[0041] The welding wire 3 has a diameter of 0.8 mm to 1.2 mm.

[0042] The present invention adopts fiber laser welding and uses Ar gas as the shielding gas. Seven groups of test data are shown below, the welding process parameters are shown in Table 1, and the weld transition state is shown in Table 2.

[0043]

[0044]

[0045] Table 1 Welding process parameters

[0046] Serial number Is there a bite edge? Weld transition result 1 no Uniform, concave qualified 2 no Uniform, concave qualified 3 no Uniform, concave qualified 4 no Uniform, concave qualified 5 no Uniform, concave qualified 6 yes Uniform, concave Failure 7 yes Poor forming Failure

[0047] Table 2 Weld transition state

[0048] According to 7 groups of test data, the top end of the welding wire 3 maintains a distance of 0 to 1 mm from the two steel plates 1 to be welded in order to achieve a liquid connection between the liquid metal of the welding wire 3 and the welding molten pool formed by the welded steel plates after the welding wire 3 is melted. If the distance is too high, the welding wire 3 cannot form a liquid connection with the welding molten pool after melting, resulting in discontinuity on the weld surface and poor weld formation.

[0049] The incident angle of the laser beam 2 is within ±10° of the bisector of the flare angle in order to obtain symmetrical melting zones on the two welded steel plates, maximize the weld penetration, and maximize the weld joint interface.

[0050] The focal point of the laser beam 2 is 0 to 10 mm away from the top axis of the welding wire 3, forming positive defocus welding. The position where the laser energy is most concentrated is not on the welding plate, thus avoiding the formation of undercut 4 defects on the steel plate.

[0051] The feeding speed V1 of the welding wire 3 is 2 to 5 times of the welding speed V2, in order to ensure the formation of an excessively uniform concave weld. The filling speed of the welding wire 3 is low, the melted welding wire 3 does not fill the trumpet-shaped joint sufficiently, the weld is not full, the weld surface is poorly formed, and an excessively uniform weld cannot be formed, resulting in a weld undercut 4 defect. The speed of the welding wire 3 is too fast, the weld filling amount is large, the laser welding penetration is reduced, the weld is easy to form an arc weld, the weld stress is large, and the weld is excessively uneven.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser welding method for a trumpet-shaped joint, characterized in that: The steps include: S1. Two steel plates to be welded form a trumpet-shaped weld, wherein at least one of the steel plates to be welded is trumpet-shaped; S2. Laser wire-filling welding is used for welding, and the wire is added at the bell mouth; S21. The distance between the top of the welding wire and the two steel plates to be welded is 0-1 mm; S22, the incident angle of the laser beam is within ±10° of the bisector of the trumpet-shaped weld angle; S23, the laser beam focus is located on the axis of the top end of the welding wire, 0 to 10 mm away from the axis of the top end of the welding wire; S24. The wire feeding speed is 2 to 5 times the welding speed.

2. The laser welding method of the trumpet-shaped joint according to claim 1, characterized in that: The diameter of the welding wire in S2 is 0.8 mm to 1.2 mm.

3. The laser welding method of the trumpet-shaped joint according to claim 2, characterized in that: The cross section of the welding wire is circular.

4. The laser welding method of a trumpet-shaped joint according to claim 1, characterized in that: In the above S21, the top end of the welding wire is within the focal range of the laser beam.

5. The laser welding method of a trumpet-shaped joint according to claim 1, characterized in that: Welding is completed when the upper surface of the weld transitions tangent to the steel plate and presents a concave shape.

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