Aluminum-silicon coating thermal forming door ring welding assembly and method

Abstract

The invention provides an aluminum-silicon coating thermal forming door ring welding assembly and method.The assembly comprises a plurality of door ring material pieces and limiting bosses, the door ring material pieces are made of steel plates with aluminum-silicon coatings, the door ring material pieces are connected end to end to form a door ring shape in a surrounding mode, the limiting bosses are arranged in pairs, and the limiting bosses are connected with the door ring material pieces in an end-to-end mode. The limiting bosses are formed in the end portions of the door ring material pieces and protrude towards the outer sides of the door ring material pieces, gaps are reserved between the limiting bosses, the tail ends of the limiting bosses are spliced with the end portions of the adjacent door ring material pieces, and welding gaps are defined between the door ring material pieces and the limiting bosses; when the welding method is adopted for splicing and welding door ring welding object workpieces and ultrahigh-frequency swing laser welding is adopted, a strong convective stirring effect can be formed in a welding pool, various element components in the welding pool can be uniformly diffused, the adverse effect of non-uniform element components on the overall strength of a welding seam is reduced, and the welding quality of the door ring welding object workpieces is improved. And head-to-tail rapid positioning of multiple plates can be achieved, the welding efficiency and quality of door ring products are effectively improved, and the cost of a tool positioning device is greatly reduced.

Description

Technical Field

[0001] The invention relates to welding technology, and in particular to an aluminum-silicon coated hot-formed door ring welding assembly and method. Background Art

[0002] The door ring structure of aluminum-silicon-plated hot-formed steel has the advantages of light weight, high strength and high collision safety, and is therefore widely used by automobile manufacturers. However, there is a problem with this door ring closed structure when performing splicing welding. When performing splicing welding, it is necessary to first place 4-6 plates end to end on the welding tooling platform, and make the gap between the two plates between 0.3-0.4mm. One method is to manually place the steel plates, adsorb them by electromagnets, and manually measure the gap, which has low production efficiency. Another method is to manually place the sheet on the tooling platform, which is equipped with an electromagnet that can control and move a certain distance. After pre-calculation, the electromagnet that needs to be moved can be driven to move to the appropriate distance, but the accuracy is low. In the above welding process, the gap of the weld is in the range of 0.3-04mm, which is a key factor in determining the quality of the weld. The above method often results in at least one weld having different widths at the beginning and end, or the gap being too wide or too narrow. Even if the welding gap is qualified, the gap of the part to be welded later will become narrower during the welding process, because the welded part will cause solidification shrinkage.

[0003] The aluminum coating of aluminum-silicon hot-formed steel will melt into the weld, and the distribution of aluminum elements in the welding pool after melting is extremely uneven. After the welding pool solidifies to form a weld, the aluminum elements in the weld will gather in some tiny areas. The strength of these tiny areas where aluminum elements gather is low, which has an adverse effect on the overall strength of the weld.

[0004] Prior art 1 Laser peeling method is to use ultra-short pulse laser to burn off the aluminum coating of the steel plate to be welded, and then weld. This method is inefficient and requires large fixed asset investment.

[0005] Prior Art 2 Laser wire filling method uses special welding wire. The addition of welding wire during welding dilutes the concentration of aluminum in the weld. At the same time, the metallurgical effect of foreign elements controls the formation of harmful substances such as aluminum compounds. However, the disadvantage is that the distribution of aluminum in the welding pool is still uneven, and harmful phases are easily generated in places where aluminum is more abundant. Therefore, an improvement measure is needed to improve the uniformity of the concentration of aluminum alloy elements in the weld in the laser wire filling welding method.

[0006] Prior art 3 relies on a galvanometer to achieve laser oscillation welding. Generally, the maximum oscillation frequency is only a few thousand times, and the oscillation trajectory can only be a simple form such as a straight line, a sawtooth, or an arc. It can play a role in homogenizing the composition of the weld to a certain extent, but its homogenization degree is difficult to further improve.

[0007] Therefore, it is necessary to carry out structural optimization to this door ring welding method to overcome the above-mentioned defects. Summary of the invention

[0008] The object of the present invention is to provide an aluminum-silicon coated hot-formed door ring welding assembly and method.

[0009] The technical solution adopted by the present invention to solve the technical problem is:

[0010] An aluminum-silicon coated hot-formed door ring welding assembly, comprising:

[0011] The door ring material sheet has several pieces, which are made of steel plates with aluminum silicon coating, and each door ring material sheet is connected end to end to enclose a door ring shape;

[0012] The limiting boss has several parts and is arranged in pairs. It is opened at the end of the door ring material and protrudes to the outside of the door ring material. A gap is left between each pair of limiting bosses, and the ends thereof are spliced ​​with the ends of the adjacent door ring material to enclose a welding gap between the door ring material and the limiting boss.

[0013] In one embodiment of the present invention, the limiting boss has a length of 3-4 mm and a width of 0.3-0.4 mm, and when its end abuts against the end of the adjacent door ring sheet, a welding gap with a width of 0.3-0.4 mm is formed.

[0014] A method for welding an aluminum-silicon coated hot-formed door ring is performed using the above-mentioned welding assembly, and comprises:

[0015] The door ring material piece is made of a steel plate with an aluminum-silicon coating, and a limiting boss is provided at the end of the door ring material piece;

[0016] Place each door ring sheet on the workpiece positioning electromagnet of the mobile welding table, and connect them end to end to form a closed door ring shape, and make the end of the limiting boss fit with the end of the adjacent door ring sheet to enclose a welding gap between the door ring sheet and the limiting boss;

[0017] The coherent laser light source is adjusted to focus the laser beam on the welding gap;

[0018] Feeding the welding wire into the welding gap through the welding wire feeding mechanism;

[0019] The end of the door ring sheet and the welding wire are melted by a laser beam to form a welding molten pool;

[0020] The focus of the laser beam is adjusted by an electrically controlled phase adjustment method to make it swing along a curved trajectory, stir it in the welding molten pool, and evenly distribute the elements in the welding molten pool to avoid local concentration and harmful phases. The laser beam is composed of multiple coherent laser beams that are phase-adjusted and then coherently synthesized into a laser beam. The phase of each independent laser beam can be adjusted electrically. When the phase changes, the focal position of the laser beam after synthesis will change accordingly, and finally it will swing along an arbitrarily set curved trajectory. This is essentially different from the principle of laser beam swing welding that relies on mechanically driven mirror swing.

[0021] In the above steps, the focal point swing trajectory of the laser beam is a multi-turn spiral or crescent shape to form different laser energy distributions.

[0022] In the above steps, the focal swing width of the laser beam is in the range of 0.5-2 mm, and its swing frequency is greater than 100,000 Hz per second. This frequency cannot be achieved by traditional galvanometer swing welding, and its frequency is usually less than 5,000 Hz.

[0023] In the above steps, the thickness of the aluminum-silicon coating of the door ring sheet is 20-50 μm. When the end of the door ring sheet and the welding wire melt, the steel plate and the aluminum-silicon coating are melted at the same time. The average concentration of the melted aluminum element in the weld is less than 0.8%-1.5%.

[0024] In the above steps, the laser beam is deflected by adjusting the phase of multiple groups of laser beams. The deflected laser beam is coherently enhanced to form a new laser beam focus, and its moving speed is 3-6M / min.

[0025] In the above steps, after the welding molten pool solidifies to form a weld, it is heated to 900-940°C for heat preservation, and is stamped and quenched through a water-permeable mold to form martensitic steel with a tensile strength greater than 1300 MPa.

[0026] In the above steps, the wavelength of the laser beam is 1024 nm, the power is 10-50 kW, and the focal point diameter is 0.3-0.9 mm.

[0027] The advantages of the present invention are:

[0028] When this method is used to perform splicing welding on the workpieces for door ring welding, a strong convection stirring effect can be formed in the welding molten pool, and the various element components in the welding molten pool can be evenly diffused, avoiding the accumulation of some elements in the weld that affect the weld strength in a small area, reducing the adverse effects of uneven element composition on the overall strength of the weld, and being able to achieve fast and easy positioning of the first position of multiple plates and control the gap, avoiding complex control mechanisms and assembly inspections, and also reducing the requirements for the dimensional accuracy of incoming materials, effectively improving the welding efficiency and quality of door ring products. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of the aluminum-silicon coated hot-formed door ring welding assembly proposed by the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme 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 part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0031] like Figure 1 As shown, the aluminum-silicon coated hot-formed door ring welding assembly proposed in the present invention includes a door ring sheet 1 and a limiting boss 2. The door ring sheet has a plurality of pieces, which are made of a steel plate with an aluminum-silicon coating. The door ring sheets are connected end to end to form a door ring shape. The limiting bosses have a plurality of pieces and are arranged in pairs. They are opened at the ends of the door ring sheets and protrude to the outside of the door ring sheets. A gap is left between each pair of limiting bosses, and their ends are spliced ​​with the ends of the adjacent door ring sheets to enclose a welding gap 3 between the door ring sheets and the limiting bosses.

[0032] In this embodiment, the limiting boss has a length of 3-4 mm and a width of 0.3-0.4 mm. When its end abuts against the end of the adjacent door ring sheet, a welding gap with a width of 0.3-0.4 mm is formed, which is the necessary space for laser wire welding.

[0033] The aluminum-silicon coated hot-formed door ring welding method proposed by the present invention adopts the above-mentioned welding assembly to perform the operation, which comprises:

[0034] The door ring material piece is made of a steel plate with an aluminum-silicon coating, and a limiting boss is provided at the end of the door ring material piece;

[0035] Place each door ring sheet on the workpiece positioning electromagnet of the mobile welding table, and connect them end to end to form a closed door ring shape, and make the end of the limiting boss fit with the end of the adjacent door ring sheet to enclose a welding gap between the door ring sheet and the limiting boss;

[0036] The coherent laser light source is adjusted to focus the laser beam on the welding gap;

[0037] Feeding the welding wire into the welding gap through the welding wire feeding mechanism;

[0038] The end of the door ring sheet and the welding wire are melted by a laser beam to form a welding molten pool;

[0039] The focus of the laser beam is adjusted by an electrically controlled phase adjustment method so that it swings along a curved trajectory and stirs the weld pool, so that the elements in the weld pool are evenly distributed to avoid local concentration of harmful phases.

[0040] In this embodiment, the focal swing trajectory of the laser beam is a multi-turn spiral or crescent shape to form different laser energy distributions to affect the flow speed and direction of the liquid metal in the welding pool. The specific trajectory can be designed through the built-in software control program of the welding equipment.

[0041] In this embodiment, the focal point swing width of the laser beam is in the range of 0.5-2 mm, and the swing frequency is greater than 100,000 Hz per second, or greater than 1,000,000 Hz.

[0042] In this embodiment, the thickness of the aluminum-silicon coating of the door ring sheet is 20-50 μm. When the end of the door ring sheet and the welding wire melt, the steel plate and the aluminum-silicon coating are melted at the same time. The average concentration of the melted aluminum element in the weld is less than 0.8%-1.5%.

[0043] In this embodiment, the laser beam is deflected by adjusting the phase of multiple groups of laser beams. The deflected laser beam is coherently enhanced to form a new laser beam focus, and its moving speed is 3-6M / min.

[0044] In this embodiment, after the welding molten pool solidifies to form a weld, it is heated to 900-940°C for heat preservation, and is stamped and quenched through a water-permeable mold to form martensitic steel with a tensile strength greater than 1300 MPa.

[0045] In this embodiment, the wavelength of the laser beam is 1024 nm, the power is 10-50 kW, and the focal point diameter is 0.3-0.9 mm.

[0046] The door knocker can be a single door knocker or a double door knocker, and a single door knocker can be composed of 2 to 8 plates.

[0047] In the description of the present invention, it should be noted that when terms such as "upper", "lower", "inner", "outer", "left", "right" and the like indicating orientation or positional relationship appear, it should be understood that the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the equipment or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, when terms such as "first" and "second" appear, they are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, terms such as "installation", "setting", and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a connection between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. An aluminum-silicon coated hot-formed door ring welding assembly, characterized in that: include: The door ring material sheet has several pieces, which are made of steel plates with aluminum silicon coating, and each door ring material sheet is connected end to end to enclose a door ring shape; The limiting boss has several parts and is arranged in pairs. It is opened at the end of the door ring material and protrudes to the outside of the door ring material. A gap is left between each pair of limiting bosses, and the ends thereof are spliced ​​with the ends of the adjacent door ring material to enclose a welding gap between the door ring material and the limiting boss.

2. The aluminum-silicon coated hot-formed door ring welding assembly according to claim 1, characterized in that: The limiting boss has a length of 3-4 mm and a width of 0.3-0.4 mm. When its end abuts against the end of the adjacent door ring sheet, a welding gap with a width of 0.3-0.4 mm is formed.

3. A method for welding an aluminum-silicon coated hot-formed door ring, using the welding assembly according to claim 1 or 2, characterized in that: include: The door ring material piece is made of a steel plate with an aluminum-silicon coating, and a limiting boss is provided at the end of the door ring material piece; Place each door ring sheet on the workpiece positioning electromagnet of the mobile welding table, and connect them end to end to form a closed door ring shape, and make the end of the limiting boss fit with the end of the adjacent door ring sheet to enclose a welding gap between the door ring sheet and the limiting boss; The welding is performed using a coherent laser light source so that the laser beam is focused on the welding gap; Feeding the welding wire into the welding gap through the welding wire feeding mechanism; The laser beam is used to melt the weld position of the door ring sheet and the welding wire to form a welding molten pool; The focal motion trajectory of the laser beam is adjusted by an electrically controlled phase adjustment method. The laser beam is formed by phase adjustment of multiple coherent laser beams and then coherent synthesis of a laser beam. The phase of each independent laser beam can be adjusted electrically. When the phase changes, the focal position of the laser beam after synthesis will eventually change accordingly, and finally it will swing along an arbitrarily set curved trajectory, stirring in the welding molten pool, so that the elements in the welding molten pool are evenly distributed, avoiding local concentration and promoting harmful phases.

4. The method for welding an aluminum-silicon coated hot-formed door ring according to claim 3, characterized in that: The laser beam focus swing trajectory is a multi-turn spiral or crescent shape to form different laser energy distributions.

5. The aluminum-silicon coated hot-formed door ring welding assembly according to claim 3, characterized in that: The focal swing width of the laser beam is in the range of 0.5-2 mm, and its swing frequency is greater than 100,000 Hz per second.

6. The aluminum-silicon coated hot-formed door ring welding assembly according to claim 3, characterized in that: The thickness of the aluminum-silicon coating of the door ring material is 20-50 μm. When the end of the door ring material, the entire weld and the welding wire are melted, the steel plate and the aluminum-silicon coating are melted at the same time, and the average concentration of the melted aluminum element in the weld is less than 0.8%-1.5%.

7. The aluminum-silicon coated hot-formed door ring welding assembly according to claim 3, characterized in that: The laser beam is deflected by adjusting the phase of multiple groups of laser beams. The deflected laser beam is coherently enhanced to form a new laser beam focus, and its moving speed is 3-6M / min.

8. The aluminum-silicon coated hot-formed door ring welding assembly according to claim 3, characterized in that: After the welding molten pool solidifies to form a weld, it is heated to 900-940℃ for insulation, and then stamped and quenched through a water-passing mold to form martensitic steel with a tensile strength greater than 1300 MPa.

9. The aluminum-silicon coated hot-formed door ring welding assembly according to claim 3, characterized in that: The wavelength of the laser beam is 1024nm, the power is 10-50kW, and the focal diameter is 0.3-0.9mm.

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