Metal welding method

Abstract

The invention discloses a metal welding method and relates to the technical field of laser welding, the metal welding method is used for welding T2 red copper and 304 stainless steel dissimilar materials, and the metal welding method comprises the following steps that laser welding equipment is obtained; processing the welding surfaces of the to-be-welded copper plate and the to-be-welded steel plate; a to-be-welded copper plate and a to-be-welded steel plate are fixed to the laser welding equipment, so that an abutted seam is formed between the opposite ends of the to-be-welded copper plate and the to-be-welded steel plate; welding parameters of the laser welding equipment are set; according to the welding parameters, the laser welding equipment is controlled to emit red and blue composite laser, and welding is conducted along the abutted seam; according to the method, self-melting matching of copper side preheating-steel side deep melting is achieved through cooperation of the double beams, the equipment cost is remarkably reduced, heat input distribution is accurately regulated and controlled through red and blue light composite light spots in the actual welding process, and the problem that cracks on the copper side are sensitive when T2 red copper / 304 stainless steel dissimilar materials are welded is solved.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, and in particular to a metal welding method. Background Technology

[0002] With the development of modern industry, the demand for engineering structural components is increasing daily in both quantity and quality. Traditional mono-alloy welded structural components are no longer sufficient to meet the actual needs of industrial production, making dissimilar alloy welded structural components a new trend in the welding field. Dissimilar material composite components possess unique engineering advantages. On the one hand, they can effectively save precious metals, thereby reducing production costs; on the other hand, they can fully exploit and leverage the performance advantages of different materials, achieving complementary strengths. In some special cases, the overall performance of dissimilar material structural components can even significantly surpass that of single-metal structural components. Therefore, people are increasingly emphasizing research on dissimilar material welding, and dissimilar material welded structural components are showing extremely broad application prospects.

[0003] Copper and copper alloys possess excellent physical, chemical, and mechanical properties, exhibiting outstanding corrosion resistance in air, fresh water, seawater, and non-oxidizing acids. Therefore, they can be used as both electrical and thermal conductive materials, as well as structural engineering materials. 304 stainless steel, due to its high strength, light weight, sufficient rigidity, and good formability, is widely used in industrial fields. When copper is welded to steel, both materials complement each other in terms of performance and cost. In the past two decades, with leaps in manufacturing technology, copper-steel dissimilar welding has become a key advanced process, playing a significant role in industries such as aerospace, petrochemicals, nuclear power, machinery, electronics, and shipbuilding.

[0004] Due to significant differences in the melting point, thermal conductivity, and coefficient of linear expansion of copper and stainless steel, the most effective welding methods for dissimilar materials such as copper / stainless steel are laser welding, friction stir welding, and plasma beam welding. However, these methods often result in noticeable burn-off of the copper base material, material loss due to spatter, and weld depressions. Using filler wire to replenish weld metal requires custom-made welding wire, increasing welding costs. Therefore, a self-fusion welding method for dissimilar materials such as T2 copper and 304 stainless steel that offers stable welding process and high weld quality is needed. Summary of the Invention

[0005] The main objective of this invention is to propose a metal welding method that aims to solve the problems of poor welding quality and high welding cost in the traditional process of welding copper and stainless steel.

[0006] To achieve the above objectives, the present invention proposes a metal welding method for welding dissimilar materials, T2 copper and 304 stainless steel, characterized in that the metal welding method includes the following steps:

[0007] Acquire laser welding equipment; The welding surfaces of the copper plate and the steel plate to be welded are treated. The copper plate and the steel plate to be welded are fixed on the laser welding equipment to form a seam between opposite ends of the copper plate and the steel plate to be welded; Set the welding parameters of the laser welding equipment; The laser welding equipment is controlled to emit a red-blue composite laser according to the welding parameters and to perform welding along the seam.

[0008] In one embodiment, setting the welding parameters of the laser welding equipment includes: Based on the absorption characteristics of the copper plate to be welded for blue light, the wavelength and output power of the blue light are determined. Based on the absorption characteristics of red light by the steel plate to be welded, determine the wavelength and output power of the red light; The total welding power is determined based on the output power of the red and blue lasers, and the actual welding speed is set simultaneously.

[0009] In one embodiment, the blue light has a wavelength of 440nm-460nm and an output power of 400W-600W; and / or, The wavelength of the red light is 1070nm-1090nm, and its output power is 1200W-1400W.

[0010] In one embodiment, controlling the laser welding equipment to emit a red-blue composite laser and perform welding along the seam according to the welding parameters includes: Adjust the output end of the laser welding equipment to the seam position; The laser is focused, and the incident angle and spot position of the laser are adjusted simultaneously to obtain the actual welding path; The laser welding equipment is controlled to operate with the set welding parameters and to perform welding along the actual welding path.

[0011] In one embodiment, simultaneously adjusting the incident angle and spot position of the laser includes: Red and blue light are coaxially combined to form a composite beam; The incident direction of the composite beam is set perpendicular to the seam position, and a welding spot is formed at the seam position; Set the offset of the welding spot at the joint position towards the side of the steel plate to be welded; The center of the welding spot is shifted toward the steel plate to be welded according to the offset amount to obtain the actual welding path of the welding spot.

[0012] In one embodiment, the bias is between 0.1 mm and 0.3 mm.

[0013] In one embodiment, controlling the laser welding equipment to operate with set welding parameters and to perform welding along the actual welding path includes: Control the laser welding equipment to output the set welding parameters; Simultaneously and evenly supply protective gas to the welding position; The composite beam is controlled to move along the actual welding path to weld the joint.

[0014] In one embodiment, the protective gas is argon, and its flow rate is 13 L / min to 17 L / min.

[0015] In one embodiment, the treatment of the welding surfaces of the copper plate and the steel plate to be welded includes: Grind the welding surfaces of the copper plate to be welded and the steel plate to be welded. Clean the surface to be welded after grinding, ensuring it is clean and dry.

[0016] In one embodiment, fixing the copper plate to be welded and the steel plate to be welded on the laser welding equipment includes: Both the copper plate and the steel plate to be welded are placed on the welding area of ​​the laser welding equipment; Connect one end of the copper plate to be welded and the steel plate to be welded, and ensure that the misalignment at the joint is below the set value; Simultaneously, downward pressure is applied to the copper plate to be welded and the steel plate to be welded, and they are fixed to the welding area.

[0017] The technical solution of the present invention has the following beneficial effects: By utilizing the high absorption rate of blue light on the copper surface, blue light energy is directed to the T2 copper side and red light is used to deeply penetrate the 304 stainless steel side. The dual beams work together to achieve self-fusion matching of "copper side preheating - steel side deep melting". Full penetration welds can be obtained at low power without copper welding wire, significantly reducing equipment costs.

[0018] The red and blue light composite spot precisely controls the heat input distribution, reducing the copper side melting amount by about 40% compared to single red light, eliminating copper grain boundary overheating and penetration cracks, and solving the problem of copper side crack sensitivity when welding dissimilar materials such as T2 copper and 304 stainless steel.

[0019] The self-fluxing process requires no filler wire, avoiding compositional segregation caused by dissimilar welding wires; the weld metal is a micro-alloyed transition layer formed by thorough mixing of copper and steel, which can effectively release residual stress through plastic deformation, and the weld surface is free of cracks.

[0020] The high absorption and low reflection characteristics of blue light suppress copper vapor ejection, while red light penetrates deeply and stabilizes small holes. Dual-wavelength coupling increases the oscillation frequency of the molten pool, which is beneficial for gas escape, reduces the porosity inside the weld, and makes the weld surface continuous and smooth.

[0021] The process is simplified to three steps: grinding, clamping, and welding. No preheating, post-heating, or beveling is required. Single-pass welding of plates with a thickness of 1mm–3mm is possible, welding time is reduced by more than 50%, and production costs are lowered.

[0022] During the self-fusion welding process, no welding wire is inserted into the molten pool, completely eliminating defects such as "unmelted welding wire" or "sticky wire". The blue light first softens the copper surface, and the red light then establishes a stable small hole. The two laser beams are output coaxially, completing the reliable connection of dissimilar materials in one go. The process window is wide and the repeatability is excellent. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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 the structures shown in these drawings without creative effort.

[0024] Figure 1 A schematic flowchart illustrating a specific embodiment of the metal welding method provided by the present invention; Figure 2 for Figure 1 A detailed flowchart of one embodiment of "setting the welding parameters of the laser welding equipment"; Figure 3 for Figure 1 A detailed flowchart of one embodiment of "controlling the laser welding equipment to emit red and blue composite lasers according to the welding parameters and welding along the seam"; Figure 4 for Figure 3 A detailed flowchart of one embodiment of "simultaneously adjusting the incident angle and spot position of the laser"; Figure 5 for Figure 3 A detailed flowchart of one embodiment of "controlling laser welding equipment to operate with set welding parameters and performing welding along the actual welding path"; Figure 6 for Figure 1 A detailed flowchart of one embodiment of "processing the welding surfaces of the copper plate to be welded and the steel plate to be welded"; Figure 7 for Figure 1 A detailed flowchart of one embodiment of "fixing the copper plate and the steel plate to be welded on the laser welding equipment"; Figure 8 For application Figure 1 A structural diagram of an embodiment of a laser welding apparatus for a metal welding method; Figure 9 To pass Figure 1 Surface morphology of dissimilar material welds (copper and steel plates) welded using the metal welding method provided in the paper; Figure 10 for Figure 9 Enlarged schematic diagram of the weld seam surface morphology in the intermediate weld seam image; Figure 11 for Figure 9 Vertical cross-sectional view of the weld seam.

[0025] Explanation of icon numbers: 100. Laser welding equipment; 1. Steel plate to be welded; 2. Copper plate to be welded; 3. Laser beam.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0029] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0030] With the development of modern industry, the demand for engineering structural components is increasing daily in both quantity and quality. Traditional mono-alloy welded structural components are no longer sufficient to meet the actual needs of industrial production, making dissimilar alloy welded structural components a new trend in the welding field. Dissimilar material composite components possess unique engineering advantages. On the one hand, they can effectively save precious metals, thereby reducing production costs; on the other hand, they can fully exploit and leverage the performance advantages of different materials, achieving complementary strengths. In some special cases, the overall performance of dissimilar material structural components can even significantly surpass that of single-metal structural components. Therefore, people are increasingly emphasizing research on dissimilar material welding, and dissimilar material welded structural components are showing extremely broad application prospects.

[0031] Copper and copper alloys possess excellent physical, chemical, and mechanical properties, exhibiting outstanding corrosion resistance in air, fresh water, seawater, and non-oxidizing acids. Therefore, they can be used as both electrical and thermal conductive materials, as well as structural engineering materials. 304 stainless steel, due to its high strength, light weight, sufficient rigidity, and good formability, is widely used in industrial fields. When copper is welded to steel, both materials complement each other in terms of performance and cost. In the past two decades, with leaps in manufacturing technology, copper-steel dissimilar welding has become a key advanced process, playing a significant role in industries such as aerospace, petrochemicals, nuclear power, machinery, electronics, and shipbuilding.

[0032] Due to significant differences in the melting point, thermal conductivity, and coefficient of linear expansion of copper and stainless steel, the most effective welding methods for dissimilar materials such as copper / stainless steel are laser welding, friction stir welding, and plasma beam welding. However, these methods often result in noticeable burn-off of the copper base material, material loss due to spatter, and weld depressions. Using filler wire to replenish weld metal requires custom-made welding wire, increasing welding costs. Therefore, a self-fusion welding method for dissimilar materials such as T2 copper and 304 stainless steel that offers stable welding process and high weld quality is needed.

[0033] This invention proposes a metal welding method.

[0034] Please see Figure 1 and Figure 8 In one embodiment of the present invention, the metal welding method is used for welding dissimilar materials T2 copper and 304 stainless steel, and the metal welding method includes the following steps: Acquire laser welding equipment; The laser welding equipment described herein differs from conventional laser welding equipment in that it can weld dissimilar materials such as T2 copper and 304 stainless steel. Specifically, it can emit composite lasers of different wavelengths, namely red and blue lasers, to address the problem of poor welding quality in the traditional process of welding T2 copper and 304 stainless steel.

[0035] The welding surfaces of the copper plate 2 and the steel plate 1 to be welded are treated. Before welding, the copper plate 2 and the steel plate 1 to be welded need to be pre-cleaned. In some embodiments, the welding surfaces of the copper plate 2 and the steel plate 1 to be welded need to be ground beforehand; Specifically, such as Figure 1 and Figure 6 As shown, use 400# and 800# sandpaper to polish the surfaces of T2 copper and 304 stainless steel to be welded in sequence to remove the oxide film. During the polishing process, pay attention to controlling the force and uniformity to ensure that the surfaces to be welded are flat and smooth, and avoid creating new defects due to improper polishing.

[0036] After grinding, the surfaces to be welded need to be cleaned to ensure they are clean and dry. This can be done by wiping with volatile solvents such as anhydrous ethanol or acetone to remove residual oxide layers, oil, and metal debris. After cleaning, drying (e.g., hot air drying or natural air drying) is necessary to ensure no moisture remains on the welding surface. This prevents defects such as porosity and cracks during welding and provides stable interface conditions for subsequent laser welding. Residual moisture or other contaminants should be avoided to prevent them from affecting the welding result.

[0037] After the copper plate 2 and the steel plate 1 to be welded are cleaned, as follows: Figure 1 and Figure 7 As shown, the copper plate 2 and the steel plate 1 to be welded need to be fixed on the laser welding equipment to form a seam between the opposite ends of the copper plate 2 and the steel plate 1 to be welded. Specifically, in some embodiments, the above-mentioned fixing operation includes the following process: First, both the copper plate 2 and the steel plate 1 to be welded need to be placed on the welding area of ​​the laser welding equipment, roughly aligning them to ensure that the joint between their opposite ends is in a suitable position and the joint width is uniform. Then, using the special clamps provided on the laser welding equipment, the copper plate and steel plate are clamped and fixed from both sides. The clamping force of the clamps should be moderate, ensuring that the copper plate and steel plate do not move relative to each other during welding, but also preventing deformation due to excessive clamping force. During the fixing process, the joint condition needs to be checked again, and any deviations should be adjusted in time to ensure welding quality.

[0038] Connect one end of the copper plate 2 to be welded with one end of the steel plate 1 to be welded, ensuring that the misalignment at the joint is below a set value (e.g., no more than 10% of the plate thickness or 0.05 mm, depending on the welding process requirements). The plates can be fixed using a special fixture or positioning tool. The misalignment can be detected in real time using a dial indicator or laser displacement sensor. If it exceeds the set value, the plate position needs to be fine-tuned until the requirements are met, ensuring that the mechanical properties and appearance quality of the welded joint meet the standards.

[0039] After the copper plate 2 and the steel plate 1 to be welded are aligned at their opposite ends, downward pressure is applied to both plates simultaneously to fix them to the welding area. A special welding fixture is used to apply clamping force perpendicular to the welding direction on both sides of the plates to prevent misalignment or deformation during welding. The pressure must be precisely controlled during the application of downward pressure and clamping force. The downward pressure needs to be determined based on the material characteristics, thickness, and welding process requirements of the copper and steel plates to ensure a tight fit without damaging the plates due to excessive pressure. The clamping force applied by the special welding fixture perpendicular to the welding direction should be evenly distributed on both sides of the plates. Precise pressure adjustment can be achieved by adjusting the bolts or hydraulic devices of the fixture. Simultaneously, the condition of the plates should be continuously observed during the application of pressure to ensure no abnormal bending or twisting occurs. If any problems are found, the pressure should be adjusted or the plates re-fixed to lay the foundation for high-quality welding operations.

[0040] As described above, after one end of the copper plate 2 to be welded and the steel plate 1 to be welded are properly connected, a seam is formed between the opposite ends of the copper plate 2 to be welded and the steel plate 1 to be welded. Generally, the seam is a straight seam. During the welding process, the laser emitted by the laser welding equipment moves along the seam, thereby forming a good fixed connection between the T2 copper and the 304 stainless steel at the seam.

[0041] It should be noted that the chemical composition of the T2 copper metal plate, by weight percentage, is: Pb≤0.005%, Fe≤0.005%, As≤0.002%, S≤0.005%, with the balance being Cu; the chemical composition of the 304 stainless steel plate, by weight percentage, is: C≤0.08%, Mn≤2%, Si≤1%, Cr18%~20%, Ni8%~10.5%, P≤0.045%, S≤0.03%, with the balance being Fe.

[0042] Before performing the above welding, the welding parameters of the laser welding equipment need to be set so as to achieve a stable and automated welding effect.

[0043] In some embodiments, it is necessary to set the welding parameters of the laser welding equipment; In the specific steps, the wavelength and output power of the blue light must first be determined based on the absorption characteristics of the copper plate to be welded to blue light. Taking advantage of the high absorption rate of blue light (around 450nm) on the copper surface, blue light energy is introduced into the T2 copper side. Specifically, the wavelength of the blue light is 440nm-460nm, and its output power is 400W-600W. Under the current control parameters, on the side of the seam corresponding to the position of the copper plate 2 to be welded, the plate can be preheated at one end of the copper plate 2 to be welded, avoiding a sudden increase in temperature on the side of the copper plate 2 to be welded, which would cause overheating of the copper grain boundaries and cracking.

[0044] Then, based on the absorption characteristics of the steel plate to be welded to red light, the wavelength and output power of the red light are determined; specifically, the wavelength of the red light is set to 1070nm-1090nm, and its output power is 1200W-1400W.

[0045] It should be noted that the aforementioned red and blue lasers are coaxial composite lasers. The total output power of the entire laser welding equipment can be obtained based on the power of the blue light. Specifically, the total power of the laser welding equipment is 1600W to 2000W. After determining the total output power, the actual welding speed needs to be set simultaneously. The actual welding speed is set to 0.012m / s to 0.018m / s.

[0046] In actual welding, operating according to the above-set total output power and actual welding speed ensures stable and reliable welding quality. When the total output power is in the range of 1600W to 2000W and the actual welding speed is between 0.012m / s and 0.018m / s, the red-blue coaxial composite laser can fully play its role in the welding process. This ensures effective heating of both the copper plate 2 and the steel plate to be welded, while avoiding welding defects caused by excessive power or improper speed, such as cracks on the copper plate side and weak welds on the steel plate, thus achieving a high-quality metal welding effect.

[0047] Once the above welding parameters are determined, the laser welding equipment can be controlled to emit a red-blue composite laser and perform welding along the seam according to the welding parameters.

[0048] During the welding process, the laser welding equipment precisely emits a red-blue composite laser according to pre-set welding parameters. This composite laser has unique advantages; the red and blue light work together to effectively heat both the copper and steel plates simultaneously. The laser moves uniformly along the pre-planned seam, with its speed strictly controlled within the previously set range of 0.012m / s to 0.018m / s. During this movement, the red-blue composite laser continues to work, ensuring the metal materials at the seam are fully melted and fused together. Because the total output power remains stable within the suitable range of 1600W to 2000W, insufficient power prevents incomplete melting of the metal, affecting weld strength, while excessive power avoids overheating and welding defects such as side cracks in the copper plate or weak welds in the steel plate. This ensures a stable and reliable welding process, ultimately yielding a high-quality welded metal product. During the specific welding process, blue light acts on the copper material to increase the absorption rate, while infrared light provides deep melting capability. The dual beams work together to achieve self-fusion matching of "copper side preheating - steel side deep melting". Full penetration welds can be obtained at low power without copper welding wire, significantly reducing equipment costs.

[0049] In some embodiments, such as Figure 1 and Figure 3 As shown, controlling the laser welding equipment to emit a red-blue composite laser and perform welding along the seam according to the welding parameters includes the following steps: First, the output end of the laser welding equipment needs to be adjusted to the seam position; During adjustment, it is essential to ensure precise alignment between the output end and the seam position, with deviations controlled within a minimal range, to guarantee that the laser can accurately target the seam area. Next, the laser welding equipment is meticulously calibrated according to the pre-set welding parameters. Specifically, the laser needs to be focused, and the incident angle and spot position of the laser need to be adjusted simultaneously to obtain the actual welding path; In this process, the incident direction of the composite laser beam is perpendicular to the surface of the workpiece, and the red light spot and the blue light spot are coaxially composited, with the focal point focused at the seam and the defocusing amount being 0.

[0050] After the adjustments are complete, the laser welding equipment needs to be controlled to operate with the set welding parameters and to perform welding along the actual welding path.

[0051] Throughout the welding process, the self-fusion process requires no filler wire, avoiding compositional segregation caused by dissimilar welding wires. The weld metal is a micro-alloyed transition layer formed by thorough mixing of copper and steel, which can effectively release residual stress through plastic deformation, resulting in a crack-free weld surface. The high absorption and low reflection characteristics of blue light suppress copper vapor ejection, while red light deeply penetrates and stabilizes the small hole. Dual-wavelength coupling increases the oscillation frequency of the molten pool, facilitating gas escape, reducing the porosity inside the weld, and ensuring a continuous and smooth weld surface. The process is simplified to three steps: grinding, clamping, and welding. No preheating, post-heating, or beveling is required. Single-pass welding of 1mm–3mm plate thickness reduces welding time by more than 50%, lowering production costs. During the self-fusion welding process, no welding wire is inserted into the molten pool, completely eliminating defects such as "unmelted welding wire" or "sticky wire." Blue light softens the copper surface first, followed by red light to establish a stable small hole. The two laser beams are output coaxially, completing a reliable connection of dissimilar materials in one operation, providing a wide process window and excellent repeatability.

[0052] In some embodiments, such as Figure 1 , Figure 3 and Figure 4 As shown, the above-mentioned simultaneous adjustment of the laser's incident angle and spot position specifically includes the following steps: Red and blue light are coaxially combined to form a composite beam. Within this composite beam, each light plays a unique role. Blue light, with its high absorption and low reflection characteristics, first acts on the copper surface, rapidly softening it and preparing it for subsequent welding. Red light, with its ability to deeply penetrate and stabilize keyholes, promptly establishes stable keyholes after the blue light softens the copper surface, ensuring stable welding. The coaxial output of both lights, working in tandem, allows for reliable joining of dissimilar materials in a single operation. This process offers a wide process window, excellent repeatability, and significantly improves welding quality and efficiency.

[0053] The incident direction of the composite beam is then set perpendicular to the seam location, forming a welding spot at the seam. By precisely controlling the laser equipment, the composite beam is accurately directed perpendicularly to the seam to be welded. This creates a welding spot of suitable size with uniform energy distribution at the seam. This spot concentrates energy to heat and melt the metal at the seam, providing the necessary energy for high-quality welding, ensuring complete fusion of the metal during the welding process, reducing welding defects, and further improving the quality and stability of the weld.

[0054] During the actual welding spot adjustment process, the offset of the welding spot towards the steel plate 1 to be welded at the joint position is set. Through the above adjustment, the heat input distribution can be precisely controlled by the red and blue composite spot. In the actual welding process, the amount of copper side melting is reduced by about 40% compared with single red light, eliminating copper grain boundary overheating and penetration cracks, and solving the problem of copper side crack sensitivity when welding dissimilar materials such as T2 copper / 304 stainless steel.

[0055] Generally, the offset is between 0.1mm and 0.3mm. In the actual welding path setting, the center of the welding spot is adjusted to shift 0.1mm-0.3mm towards the steel plate 1 to be welded, based on the offset, to obtain the actual welding path. Welding controlled by the above parameters can form a welding path as shown above. Figures 9 to 11 The welding performance of the steel plate 1 and the copper plate 2 to be welded is shown in the relevant attached figures. It can be seen that the copper plate 2 and the steel plate 1 to be welded have formed a good welding fixation relationship. The cross-sectional view shows that the weld penetration is relatively ideal, and a good connection performance is formed between dissimilar materials.

[0056] In some embodiments, such as Figure 1 , Figure 3 and Figure 5 As shown, the specific steps for controlling the laser welding equipment to operate with the set welding parameters and to perform welding along the actual welding path are as follows: Control the laser welding equipment to output the set welding parameters; The laser welding equipment emits the aforementioned red-blue composite laser to weld the joint between the copper plate 2 and the steel plate 1. During the welding process, the temperature at the welding position is relatively high, which easily leads to oxidation and a decrease in the strength of the welded area. To avoid this, a protective gas needs to be uniformly supplied to the welding position simultaneously during the welding process. The protective gas is argon, with a flow rate of 13-17 L / min. The protective gas is directed at the welding location to prevent oxidation at the joint during welding. When the protective gas supply is normal, the composite beam can be controlled to move along the actual welding path to weld the joint. After welding, the weld is allowed to cool naturally to room temperature, resulting in a uniform weld surface free of cracks and porosity, achieving a high-quality self-fusion connection between copper and 304 stainless steel dissimilar materials.

[0057] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A metal welding method for welding dissimilar materials T2 copper and 304 stainless steel, characterized in that, The metal welding method includes the following steps: Acquire laser welding equipment; The welding surfaces of the copper plate and the steel plate to be welded are treated. The copper plate and the steel plate to be welded are fixed on the laser welding equipment to form a seam between opposite ends of the copper plate and the steel plate to be welded; Set the welding parameters of the laser welding equipment; The laser welding equipment is controlled to emit a red-blue composite laser according to the welding parameters and to perform welding along the seam.

2. The metal welding method as described in claim 1, characterized in that, Setting the welding parameters of the laser welding equipment includes: Based on the absorption characteristics of the copper plate to be welded for blue light, the wavelength and output power of the blue light are determined. Based on the absorption characteristics of red light by the steel plate to be welded, determine the wavelength and output power of the red light; The total welding power is determined based on the output power of the red and blue lasers, and the actual welding speed is set simultaneously.

3. The metal welding method as described in claim 2, characterized in that, The blue light has a wavelength of 440nm-460nm and an output power of 400W-600W; and / or, The wavelength of the red light is 1070nm-1090nm, and its output power is 1200W-1400W.

4. The metal welding method as described in claim 1, characterized in that, The step of controlling the laser welding equipment to emit a red-blue composite laser and weld along the seam according to the welding parameters includes: Adjust the output end of the laser welding equipment to the seam position; The laser is focused, and the incident angle and spot position of the laser are adjusted simultaneously to obtain the actual welding path; The laser welding equipment is controlled to operate with the set welding parameters and to perform welding along the actual welding path.

5. The metal welding method as described in claim 4, characterized in that, Simultaneously adjust the incident angle and spot position of the laser, including: Red and blue light are coaxially combined to form a composite beam; The incident direction of the composite beam is set perpendicular to the seam position, and a welding spot is formed at the seam position; Set the offset of the welding spot at the joint position towards the side of the steel plate to be welded; The center of the welding spot is shifted toward the steel plate to be welded according to the offset amount to obtain the actual welding path of the welding spot.

6. The metal welding method as described in claim 5, characterized in that, The offset is between 0.1 mm and 0.3 mm.

7. The metal welding method as described in claim 4, characterized in that, The control of the laser welding equipment to operate with set welding parameters and to perform welding along the actual welding path includes: Control the laser welding equipment to output the set welding parameters; Simultaneously and evenly supply protective gas to the welding position; The composite beam is controlled to move along the actual welding path to weld the joint.

8. The metal welding method as described in claim 7, characterized in that, The protective gas is argon, and its flow rate is 13L / min-17L / min.

9. The metal welding method as described in claim 1, characterized in that, The treatment of the welding surfaces of the copper plate and the steel plate to be welded includes: Grind the welding surfaces of the copper plate to be welded and the steel plate to be welded. Clean the surface to be welded after grinding, ensuring it is clean and dry.

10. The metal welding method as described in claim 1, characterized in that, Fixing the copper plate and steel plate to be welded on the laser welding equipment includes: Both the copper plate and the steel plate to be welded are placed on the welding area of ​​the laser welding equipment; Connect one end of the copper plate to be welded and the steel plate to be welded, and ensure that the misalignment at the joint is below the set value; Simultaneously, downward pressure is applied to the copper plate to be welded and the steel plate to be welded, and they are fixed to the welding area.

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