Dissimilar metal welding structure, refrigeration accessory and refrigeration system

Abstract

The utility model provides a dissimilar metal welding structure, a refrigeration accessory and a refrigeration system. The dissimilar metal welding structure comprises a first component and a second component. A hollow bearing part made of non-nonferrous metal is formed on the first component. And the second component comprises an inserting part made of non-ferrous metal, the inserting part is inserted into the bearing part on the first component, and a sleeving area is formed by an assembling overlapping area of the inserting part and the bearing part. Wherein a laser penetrating welding seam formed by laser welding or laser wire feeding welding is formed on the peripheral wall of the bearing part of the sleeving area, the laser penetrating welding seam penetrates through the peripheral wall of the bearing part in the radial direction of the bearing part and extends into the peripheral wall of the inserting part of the second component, and the axial distance L from the laser penetrating welding seam to the end face of the bearing part is larger than or equal to 0.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration components technology, and particularly to dissimilar metal welding structures, refrigeration components and refrigeration systems. Background Technology

[0002] The high price of copper has driven the development of refrigeration components towards lower-cost materials, such as steel, with less copper. However, due to the limitations of existing copper piping in refrigeration systems, steel refrigeration components require copper connection sections to facilitate welding to the copper piping. Welding copper and steel is dissimilar metal welding, and the differences in their physical properties, such as melting point, thermal conductivity, coefficient of linear expansion, and mechanical properties, create numerous difficulties. Therefore, current copper-steel dissimilar metal welding commonly uses tin bronze brazing in a furnace. However, due to the characteristics of tin bronze brazing, the resulting tin bronze brazing layer has a loose microstructure, and the tin element can enhance penetration cracks during copper-steel welding, leading to lower connection strength. Furthermore, due to the pipe manufacturing process, the larger the pipe diameter, the more difficult it is to control its roundness, resulting in poorer uniformity of the gap between the assembled copper and steel pipes. Since tin bronze brazing penetrates into the gap through capillary action, it has high requirements for the assembly gap (generally -0.05mm to 0.1mm). Therefore, when the pipe diameter is large, the ellipticity formed during pipe manufacturing will cause some gaps to exceed the capillary penetration gap requirements of tin bronze, resulting in weld breakage in some areas, which will further deteriorate the connection strength of large-diameter copper-steel secondary components when using tin bronze brazing.

[0003] With the continuous development of welding technology, some have proposed using a combination of brazing and fusion welding for welding dissimilar metals like copper and steel, as exemplified by Chinese patents CN204913089 U and CN109954996A. Fusion welding currently primarily employs laser welding or argon arc welding. For laser welding, copper, being a non-ferrous metal, exhibits strong reflection of the laser beam, making it difficult to absorb laser heat and prone to porosity during melting, severely impacting the weld's airtightness and connection strength. Argon arc welding, on the other hand, suffers from undercut at the joint during arc termination, affecting weld airtightness, and hot cracks and penetration cracks can also appear, impacting weld strength. Furthermore, the pre-formed fusion weld in this method can hinder brazing filler penetration, leading to partial weld breaks, making it impossible to rely on brazing layers for sealing. Therefore, the welding solutions provided by Chinese patents CN204913089 U and CN109954996A are still not applicable to the welding of dissimilar metals such as copper and steel due to the limitations of the airtightness and connection strength of existing fusion welds. Utility Model Content

[0004] In order to overcome the shortcomings of the prior art, this utility model provides a dissimilar metal welding structure with high connection strength, refrigeration accessories and refrigeration system.

[0005] To achieve the above objectives, this utility model provides a dissimilar metal welding structure, comprising a first component and a second component. The first component has a hollow receiving portion made of a non-ferrous metal. The second component includes a plug-in portion made of a non-ferrous metal, which is inserted into the receiving portion of the first component, and the overlapping area of ​​the two forms a socket area. A laser-penetrating weld, formed by laser welding or laser wire feeding welding, is formed on the peripheral wall of the receiving portion in the socket area. The laser-penetrating weld penetrates the peripheral wall of the receiving portion radially and extends into the peripheral wall of the plug-in portion of the second component, and the axial distance L from the laser-penetrating weld to the end face of the receiving portion is ≥ 0.

[0006] According to one embodiment of the present invention, the number of laser-penetrated welds on the peripheral wall of the receiving portion of the socket area is one or more.

[0007] According to one embodiment of the present invention, the end face of the plug extends into a receiving portion, and two laser-penetrating welds are formed on the socket area at both ends of the outer peripheral wall of the receiving portion.

[0008] According to one embodiment of the present invention, a brazing layer is formed in the assembly gap between the receiving part and the insertion part, and the length L1 of the brazing layer is greater than or equal to the larger of 0.05Φ and 2.5mm, where Φ is the diameter of the hole at the receiving part.

[0009] According to one embodiment of the present invention, the brazing layer is an alloy layer formed by welding tin bronze brazing material or brazing material with a liquidus temperature below 920°C.

[0010] According to one embodiment of the present invention, at the socket area of ​​the insertion part and the receiving part, an exhaust hole is formed on the tube wall of the insertion part, which communicates with the inner cavity of the second component and is used to discharge brazing gas.

[0011] According to one embodiment of the present invention, the non-ferrous metal is carbon steel or alloy steel, and the non-ferrous metal is any one or more combinations of aluminum, aluminum alloy, copper, or copper alloy.

[0012] According to one embodiment of the present invention, both the first component and the second component are hollow tubular fittings;

[0013] Alternatively, the first component is a hollow container made of non-ferrous metal, with a receiving part formed at the connection hole on the hollow container, and the second component is a hollow tube.

[0014] Alternatively, the first component is a hollow tube, and the second component is an end cap or end plate.

[0015] On the other hand, this utility model also provides a dissimilar metal welding structure, which includes a first component and a second component. The first component has a hollow receiving portion made of a non-ferrous metal. The second component includes an insertion portion made of a non-ferrous metal, the receiving portion being inserted into the receiving portion on the first component.

[0016] An arc-assisted self-fusion weld is formed between the receiving part and the insert part. The arc-assisted self-fusion weld is an alloy layer comprising non-ferrous metal elements on the receiving part, non-ferrous metal elements on the insert part, and a third metal element. The third metal element is any one or more combinations of nickel, aluminum, and silicon. The brazing filler metal containing nickel in the arc-assisted self-fusion weld is a nickel-based brazing filler metal with a nickel percentage of ≥60%.

[0017] According to one embodiment of the present invention, a brazing layer is formed in the assembly gap between the receiving part and the insertion part, and the length L1 of the brazing layer is greater than or equal to the larger of 0.05Φ and 2.5mm, where Φ is the diameter of the hole at the receiving part.

[0018] The brazing layer is formed by welding tin bronze brazing material or brazing material with a liquidus temperature below 920°C.

[0019] On the other hand, this utility model also provides a refrigeration accessory, which includes the above-mentioned dissimilar metal welded structure.

[0020] According to one embodiment of the present invention, the refrigeration accessory further includes a connecting pipe made of non-ferrous metal, wherein at least one end of the connecting pipe is provided with the dissimilar metal welding structure, and at least one end of the connecting pipe is welded to a first component in the dissimilar metal welding structure.

[0021] On the other hand, this utility model also provides a refrigeration system, which includes the above-mentioned dissimilar metal welded structure or the above-mentioned refrigeration components.

[0022] In summary, the dissimilar metal welding structure provided by this utility model employs laser welding for through-welding between non-ferrous and non-ferrous metals. During assembly, a non-ferrous metal insert in the second component is inserted into the non-ferrous metal receiving part in the first component. This arrangement ensures that during welding, the laser beam only irradiates the outer peripheral wall of the non-ferrous metal receiving part, and not the highly reflective non-ferrous metal insert. The low reflectivity of the non-ferrous metal receiving part allows it to absorb a large amount of laser beam energy. The heat penetrates the receiving part radially and partially melts the peripheral wall of the insert to form a molten pool, effectively solving the problem of laser welding difficulties caused by the extremely high and unstable reflectivity of non-ferrous metals. Compared to the loosely structured brazed layer formed by metallurgical diffusion dissolution, the laser-penetrating weld is a through-weld structure formed by the melting of dissimilar metal base materials and the recrystallization of elements through homogeneous epitaxy. This weld is not only dense and has high connection strength, but also exhibits excellent performance in terms of plasticity, toughness, and corrosion resistance. In addition, laser welding is not only highly efficient, but the welding heat does not affect the grain size of the second component, ensuring that the second component still has excellent connection strength and pressure resistance after welding.

[0023] Furthermore, the dissimilar metal welding structure provided by this utility model, based on laser-penetrated weld seam, employs brazing to form a brazing layer in the assembly gap between the receiving part and the insertion part, thereby further improving the welding strength of dissimilar metals.

[0024] To make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0025] Figure 1 The diagram shown is a schematic diagram of the dissimilar metal welding structure provided in Example 1 of this utility model.

[0026] Figure 2 As shown Figure 1 Enlarged diagram of point A in the middle.

[0027] Figure 3 and Figure 4 The diagram shown is a schematic diagram of a dissimilar metal welding structure provided in another embodiment of this utility model.

[0028] Figure 5 The diagram shown is a structural schematic of the refrigeration accessory provided in Embodiment 1 of this utility model.

[0029] Figure 6 and Figure 7 The diagram shown is a schematic diagram of a dissimilar metal welding structure provided in another embodiment of this utility model.

[0030] Figure 8The diagram shown is a structural schematic of a refrigeration accessory provided in another embodiment of this utility model.

[0031] Figure 9 The diagram shown is a schematic diagram of the dissimilar metal welding structure provided in Embodiment 2.

[0032] Figure 10 The diagram shown is a schematic diagram of the dissimilar metal welding structure provided in Embodiment 3 of this utility model.

[0033] Figure 11 The diagram shown is a schematic diagram of a dissimilar metal welding structure provided in another embodiment of this utility model.

[0034] Figure 12 The diagram shown is a structural schematic of the refrigeration accessory provided in Embodiment 3 of this utility model.

[0035] Figure 13 The diagram shown is a structural schematic of a refrigeration accessory provided in another embodiment of this utility model.

[0036] Figure 14 The diagram shown is a schematic diagram of the dissimilar metal welding structure provided in Embodiment 4 of this utility model.

[0037] Figure 15 The diagram shown is a schematic diagram of a dissimilar metal welding structure provided in another embodiment of this utility model.

[0038] Figure 16 As shown Figure 14 A schematic diagram of the structure of the second component.

[0039] Figure 17 The diagram shown is a structural schematic of the second component provided in another embodiment of this utility model.

[0040] Figure 18 The diagram shown is a schematic diagram of the dissimilar metal welding structure provided in Embodiment 5 of this utility model.

[0041] Figure 19 and Figure 20 The diagram shown is a schematic diagram of a dissimilar metal welding structure provided in another embodiment of this utility model. Detailed Implementation

[0042] Example 1

[0043] Currently, dissimilar metals such as copper and steel are typically welded using brazing, or a combination of brazing and fusion welding. Due to the microstructure of the brazed layer and its assembly requirements, brazing dissimilar metals results in not only low joint strength but also poor sealing and toughness. In the combination of fusion welding and brazing, copper, as a non-ferrous metal, exhibits high reflectivity to laser beams, making laser self-fusion welding difficult. Therefore, only argon arc welding, with its poor weld properties, can be used for self-fusion welding. Furthermore, in existing combinations of fusion welding and brazing, the heat from fusion welding can cause secondary fusion of the formed brazed layer, severely affecting its joint strength and sealing.

[0044] In view of this, this embodiment provides a dissimilar metal welded structure with excellent weld performance. For example... Figure 1 As shown, the dissimilar metal welding structure provided in this embodiment includes a first component 1 and a second component 2. A hollow receiving portion 11 made of non-ferrous metal is formed on the first component 1. The second component 2 includes an insertion portion 21 made of non-ferrous metal, which is inserted into the receiving portion 11 on the first component 1, and the overlapping area of ​​the two forms a socket area 10. A laser-penetrating weld 20, formed by laser welding or laser wire feeding welding, is formed on the peripheral wall of the receiving portion 11 in the socket area. The laser-penetrating weld 20 penetrates the peripheral wall of the receiving portion 11 radially and extends into the peripheral wall of the insertion portion 21, and the axial distance L from the laser-penetrating weld 20 to the end face of the receiving portion 11 is ≥ 0.

[0045] In this embodiment, the first component 1 is a hollow tube and the non-ferrous metal is stainless steel, and the second component 2 is also a hollow tube and the non-ferrous metal is copper. However, this utility model does not impose any limitations on this. In other embodiments, the non-ferrous metal may be other carbon steel or alloy steel with iron as the base material, and the non-ferrous metal may be any one or more combinations of aluminum, aluminum alloy, copper, or copper alloy.

[0046] In this embodiment, the laser-penetrating weld 20 is a joint formed by the mutual dissolution of metallic elements between the peripheral wall of the receiving portion 11 and the peripheral wall of the insertion portion 21 after laser welding or laser wire feeding welding. The penetration depth of the laser-penetrating weld 20 in the insertion portion 21 is less than that of the peripheral wall of the insertion portion 21, that is, the end of the laser-penetrating weld 20 is located inside the peripheral wall of the insertion portion 21, and it does not penetrate the peripheral wall of the insertion portion 21.

[0047] Non-ferrous metals typically have high thermal conductivity (such as copper and aluminum) and exhibit extremely strong and unstable reflectivity to laser beams. These factors make it very difficult for non-ferrous metals to absorb the heat from the laser beam for base metal melting and welding. Therefore, current laser welding of non-ferrous metals requires high-power lasers to increase the input heat. Although the high reflectivity of non-ferrous metal surfaces makes it difficult for them to absorb laser beam heat, once the base metal begins to melt, the absorption rate of the molten pool to the laser beam increases dramatically. When the base metal temperature approaches its boiling point, the molten pool can absorb 90% of the laser beam's heat. At this point, the heat input from the high-power laser will be excessive, easily causing base metal damage, burn-in, and other welding quality problems. Furthermore, excessively high laser beam heat can also increase the solubility of some non-metallic elements in non-ferrous metals, such as the solubility of hydrogen in aluminum, leading to porosity in the weld and severely affecting weld performance.

[0048] To address this issue, this embodiment inserts a non-ferrous metal connector 21 into the non-ferrous metal receiving portion 1 within the first component 1, with the overlapping area forming a socket area 10. This arrangement ensures that during welding, the laser beam only irradiates the outer peripheral wall of the non-ferrous metal receiving portion 11 within the socket area, avoiding the highly reflective connector 21. The low-reflectivity receiving portion 11 rapidly absorbs the laser beam energy, allowing heat to penetrate radially and partially melt the wall of the connector 21, forming a laser-penetrating weld 20. This heat-conduction laser welding based on the receiving portion 11 effectively solves the problem of difficult laser welding of non-ferrous metals and provides conditions for stable, high-quality welding using lower-power lasers. Specifically, since the surface of the non-ferrous metal receiving portion 11 effectively absorbs the heat from the input laser beam, the laser power can be selected based on the energy required to melt the receiving portion 11 during welding, without considering reflection factors and selecting an excessively high-power laser. The low-power laser not only provides stable and easily controllable input heat, but also ensures that the heat conducted to the insertion portion 21 within the second component 2 is not excessive. Therefore, it allows for precise control of the laser penetration distance of the weld 20 within the insertion portion 21, effectively preventing burn-through caused by excessive input heat while maintaining welding strength. Furthermore, precise control of welding heat effectively inhibits the solubility of some non-metallic elements, thereby significantly improving the laser penetration performance of the weld 20.

[0049] Compared to brazing layers formed by metallurgical diffusion and intermingling (especially the porous tin bronze brazing layer formed when brazing dissimilar metals like copper and steel), laser-penetrating weld 20, which is of the same composition as the base material and connected by metallic bonds, is far superior to traditional brazing layers in terms of connection strength, corrosion resistance, and toughness. Furthermore, laser welding is a localized heating welding process; the heat from the laser beam only affects a very small area of ​​the base material near the laser-penetrating weld 20. The welding heat does not affect the grain size of the second component 2 (i.e., the copper material) outside the socket area 10, thus allowing it to maintain excellent material properties after welding, such as superior connection strength, pressure resistance, and toughness.

[0050] Although this embodiment uses laser welding to form a laser-penetrating weld 20 as an example for description, the present invention does not limit this in any way. In other embodiments, after the laser welding forms a molten pool, a brazing filler metal containing a third metal can be fed into the molten pool by wire feeding, thereby further improving the performance of the laser-penetrating weld 20 by adding a third metal element. Specifically, the added metal element can be any one or more combinations of nickel, aluminum, and silicon.

[0051] like Figure 1 and Figure 2 As shown, a laser-penetrating weld 20 is formed on the peripheral wall of the receiving portion 11 in the socket area 10, and this laser-penetrating weld 20 is located near the end face of the receiving portion 11. This arrangement allows excess welding heat to be quickly released from the assembly gap between the receiving portion 11 and the insertion portion 21 to the end face of the receiving portion 11 and conducted to the low-temperature air outside via the second component 2, which has excellent thermal conductivity. This shortens the heat transfer path of excess welding heat, thereby rapidly reducing the temperature within the assembly gap and effectively preventing excessive welding heat accumulation that could cause the insertion portion 21 to burn through. Preferably, the axial distance L from the laser-penetrating weld 20 to the end face of the receiving portion 11 is set as close to 0 as possible, provided that the surface of the second component 2 does not reflect the laser beam. However, this invention does not impose any limitation on this. In other embodiments, the axial distance L from the laser-penetrating weld 20 to the end face of the receiving portion 11 can also be other values ​​greater than zero, meaning that laser welding can be performed at any peripheral wall of the receiving portion 11 within the socket area 10 to form the laser-penetrating weld 20.

[0052] Although this embodiment uses a single laser-penetrating weld 20 as an example, the present invention does not limit this. In other embodiments, multiple laser-penetrating welds 20 may be provided to improve the connection strength between the receiving portion 11 in the first component 1 and the insertion portion 21 in the second component 2, such as... Figure 3 and Figure 4 As shown. In Figure 3In the socket area 10, two laser-penetrating welds 10 are formed on the periphery of the receiving portion 11, one near the end face of the receiving portion 11 and the other near the end face of the insertion portion 21. Figure 4 In the middle, three laser-penetrating weld seams 20 are formed on the periphery of the receiving part 11 of the socket area 10.

[0053] In the dissimilar metal welding structure provided in this embodiment, when applied, the first component 1 made of non-ferrous metal is welded to an external non-ferrous metal component (such as a stainless steel component), while the second component 2 made of non-ferrous metal is connected to an external non-ferrous metal component (such as a copper pipe in a refrigeration system).

[0054] Correspondingly, this embodiment provides a refrigeration accessory. For example... Figure 5 As shown, the refrigeration accessory includes a connecting pipe 200 made of non-ferrous metal and a dissimilar metal welded structure 100 welded to the end of the connecting pipe 200. In this embodiment, the connecting pipe 200 is a stainless steel pipe, and its end is welded to a first component 1 made of stainless steel in the dissimilar metal welded structure 100 by argon arc welding. However, this utility model does not impose any limitations on this. In other embodiments, the connecting pipe may also be other carbon steel or alloy steel with iron as the base material.

[0055] To facilitate the connection between the stainless steel refrigeration components and external copper piping, a copper connecting section is required on the stainless steel refrigeration components. Currently, tunnel furnace brazing is mainly used to weld the refrigeration component body and the copper connecting section. However, the large size of the refrigeration component body entering the furnace severely affects welding efficiency, and the prolonged high-temperature brazing in the tunnel furnace also increases the grain size of the copper connecting section, affecting its connection strength. In the refrigeration components provided in this embodiment, the dissimilar metal welding structure 100 formed by laser penetration weld 20 eliminates the need for prolonged high-temperature brazing of the second component 2 made of copper, ensuring that it still has superior strength and ductility after welding. At the same time, in the refrigeration components provided in this embodiment, the large-size connecting pipe 200 and the dissimilar metal welding structure 100 are processed independently, reducing the welding process of the large-size connecting pipe 200, thereby greatly reducing processing costs and improving processing efficiency.

[0056] Although this embodiment uses the example of a dissimilar metal welding structure 100 welded to one end of the connecting pipe 200, this invention does not impose any limitations on it. In other embodiments, dissimilar metal welding structures may be provided at both ends of the connecting pipe.

[0057] Figure 6Another dissimilar metal welding structure is also provided, in which the first component 1 is a relatively short hollow tube with open ends. The insertion part 21 is inserted from one end of the first component 1 and extends out from the other end, with the first component 1 serving as the entire receiving part 11. Two laser-penetrating weld seams 20 are formed on the socket area 10 at both ends of the outer peripheral wall of the receiving part 11. When forming the laser-penetrating weld seam 20 near the end face of the insertion part 21, excess welding heat can also be quickly released from the assembly gap between the receiving part 11 and the insertion part 21 to the other end face of the receiving part 11 and quickly conducted to the external low-temperature air through the insertion part 21, so as to effectively avoid the welding burn-through of the insertion part 21 caused by the accumulation of welding heat in the assembly gap. However, this utility model does not limit this in any way. In other embodiments, the end face of the insertion part 21 may not extend out of the receiving part 11, but is basically close to the other end face of the receiving part 11, such as Figure 7 As shown. Similarly, when the laser-penetrating weld 20 is formed near the end face of the plug part 21, the welding heat in the assembly gap can also be quickly transferred to the end face of the plug part 21, and then conducted to the low temperature environment to effectively avoid the accumulation of welding heat.

[0058] Figure 8 The image shows another refrigeration accessory provided by this utility model. This refrigeration accessory includes a connecting pipe 200 and a component welded to at least one end of the connecting pipe 200. Figure 5 The dissimilar metal welding structure 100 is shown. In this structure, the end of the connecting pipe 200 is argon arc welded to the first component 1 of the same material in the dissimilar metal welding structure 100.

[0059] This utility model does not limit the application of the dissimilar metal welding structure provided in this embodiment. It can also be applied to branch pipes of liquid separators, branch pipes of water collectors, branch pipes of branch pipes, inner pipes of air conditioning compressor suction pipes, outer pipes of suction pipes, exhaust pipes, inlet pipes or outlet pipes of compressor receivers, piping on air conditioning silencers, piping for gas-liquid separators or oil-gas separators, piping for air conditioning shut-off valves, piping for air conditioners, pipe fittings, connecting pipes, piping on refrigeration electromagnetic reversing valves, piping on air conditioning electronic expansion valves, etc.

[0060] Correspondingly, this embodiment also provides a refrigeration system including the above-mentioned dissimilar metal welded structure or refrigeration components.

[0061] Example 2

[0062] This embodiment is basically the same as Embodiment 1 and its variations, except that: in this embodiment, the first component 1 is a hollow container made of non-ferrous metal, and a receiving portion 11 is formed at the nozzle hole on the hollow container. A hollow pipe made of non-ferrous metal serves as the second component 2, with its insertion portion 21 inserted into the receiving portion 11, and the overlapping area of ​​the two forming a socket area 10. A laser-penetrating weld 20 penetrates the peripheral wall of the receiving portion 11 (nozzle hole) radially along the socket area and extends into the peripheral wall of the insertion portion 21, as shown below. Figure 9 As shown.

[0063] In this embodiment, the hollow container made of non-ferrous metal is a carbon steel container or an alloy steel container with iron as the base material; specifically, it can be a hollow body container such as a liquid storage body, a silencer body, or a filter body.

[0064] In this embodiment, the second component 2 is a hollow tube made of copper. However, this invention does not limit this to any particular material. The second component may also be any one or more combinations of aluminum, aluminum alloy, copper, or copper alloy.

[0065] Example 3

[0066] This embodiment is basically the same as Embodiment 1 and its variations, except that: in this embodiment, the first component 1 is a hollow tube made of non-ferrous metal, with one end serving as a receiving part 11. The second component 2 is an end cap, with the large-diameter section of the end cap serving as a insertion part 21 to be inserted into the receiving part 11 of the first component 1, and the two are welded together by laser-penetrating weld 20, as shown below. Figure 10 As shown.

[0067] Furthermore, the dissimilar metal welding structure 100 provided in this embodiment also includes a second component 2'. Specifically, the other end of the first component 1 also forms a receiving portion 11', and the second component 2' is an end plate made of non-ferrous metal material, which is wholly or partially embedded in the receiving portion 11', with the embedded portion serving as a plug-in portion. Figure 10 In this embodiment, the second component 2' is entirely embedded within the receiving portion 11', thus serving as an insertion part. A laser-penetrating weld 20' is formed in the overlapping area of ​​the second component 2' and the receiving portion 11', penetrating the receiving portion 11' radially and extending into the end plate (second component 2'). However, this invention does not limit the scope of the invention. In other embodiments, the dissimilar metal welding structure may also only include an end cap welded to the receiving portion 11, such as... Figure 11 As shown; or, only the end plate welded to the receiving part 11'.

[0068] In this embodiment, the second component 2' includes two end plates stacked sequentially, each end plate having a coaxial end plate hole to coexist and form a branch pipe hole. However, this utility model does not impose any limitations on this. In other embodiments, the second component may also be a single end plate or three or more end plates stacked sequentially.

[0069] Correspondingly, this embodiment also provides a refrigeration accessory including the above-described dissimilar metal welded structure 100. For example... Figure 12 As shown, the refrigeration accessory is a liquid distributor, which includes a liquid distributor body 201, a copper inlet pipe 202, multiple copper branch pipes 203, and a mixing guide 204 disposed in the liquid distributor body 201. Figure 10 The dissimilar metal welded structure 100 shown forms the body 201 of the liquid distributor. The first component 1 is made of stainless steel, while the end cap (second component 2) and end plate (second component 2') are both made of copper. The copper inlet pipe 202 is connected to the inlet pipe hole on the end cap (second component 2) by flame brazing, and multiple copper branch pipes 203 are respectively connected to the corresponding branch pipe holes on the end plate (second component 2') by flame brazing.

[0070] Figure 13 The image shows a refrigeration accessory provided in another embodiment of this utility model. This refrigeration accessory is a water collection head, which includes a threaded connection section 302 made of stainless steel, a water collection head body 301 formed by a dissimilar metal welded structure 100, and multiple copper branch pipes 303. Figure 13 In the process, the main body 301 of the water collection head formed by the dissimilar metal welding structure 100 includes a first component 1 formed by a hollow pipe and a second component 2' formed by an end plate. The end plate (second component 2') is embedded in the receiving part 11 on the first component 1 and the two are welded together by a laser-penetrating weld 20.

[0071] Example 4

[0072] This embodiment is basically the same as Embodiment 1 and its variations, except that: in this embodiment, a brazing layer 30 is formed in the assembly gap between the receiving part 11 and the insertion part 21, and the length L1 of the brazing layer 30 is greater than or equal to the larger of 0.05Φ and 2.5mm, where Φ is the diameter of the hole at the receiving part 11.

[0073] like Figure 14As shown, the laser-penetrating weld 20 is located near the end face of the insertion part 21, and the brazing material penetrates into the assembly gap from the side where the end face of the receiving part 11 is located. During processing, the laser-penetrating weld 20 is formed first, followed by brazing to form the brazed layer 30. This arrangement effectively avoids the problem of secondary melting of the brazed layer caused by the heat of laser welding, ensuring the connection strength and sealing of the brazed layer 30. However, this invention does not limit this to any specific embodiment. In other embodiments, the laser-penetrating weld 20 may also be located near the end face of the receiving part 11, and the brazing material may penetrate into the assembly gap from the side where the end face of the insertion part 21 is located, such as... Figure 15 As shown.

[0074] Specifically, the first component 1 is made of stainless steel, and the second component 2 is made of copper. After the two are welded to form a laser-penetrating weld 20, tunnel furnace brazing is performed using tin bronze brazing filler metal to form a brazing layer 30. However, this invention does not limit this. In other embodiments, brazing filler metal with a liquidus temperature below 920°C (such as copper-silver-phosphorus brazing filler metal) can also be used for tunnel furnace brazing to avoid a decrease in hardness caused by the increased grain size of the second component 2 after prolonged high-temperature tunnel furnace brazing. However, this invention does not limit this. In other embodiments, other brazing methods such as flame brazing and high-frequency brazing can also be used.

[0075] Although this embodiment uses a continuous circumferential weld as an example of laser-penetrated weld, the present invention does not limit this in any way. The brazing layer also allows the laser-penetrated weld in other embodiments to be multiple spaced, localized welds.

[0076] In this embodiment, to further increase the penetration path of the brazing layer 30, an exhaust hole 22 is formed on the peripheral wall of the insertion portion 21 at the socket area 10, which communicates with the inner cavity of the second component 2 and is used to discharge brazing gas. Figure 16 As shown. During brazing, the gas in the assembly gap is discharged into the inner cavity of the second component 2 through the vent holes 22, reducing the resistance in the assembly gap and improving the penetration path of the brazing filler metal. In this embodiment, two rows of vent holes are provided on the peripheral wall of the insertion part 21, distributed along the axial direction of the second component 2, and each row includes multiple vent holes 22 distributed circumferentially. However, this utility model does not limit this in any way. In other embodiments, a single row (e.g., ...) may also be provided on the second component 2. Figure 17 (As shown) or three or more rows of vent holes 22, or other irregular arrangements. Furthermore, in other embodiments, vent holes may also be opened on the peripheral wall of the receiving portion of the socket area; in this case, it is preferable to set the laser-penetrating weld near the end face of the insertion portion.

[0077] Example 5

[0078] This embodiment provides another dissimilar metal welding structure, such as Figure 18As shown, it includes a first component 1 and a second component 2. The first component 1 has a hollow receiving portion 11 made of non-ferrous metal. The second component 2 includes a plug portion 21 made of non-ferrous metal, which is inserted into the receiving portion 11 of the first component 1.

[0079] An arc-assisted self-fusion weld 40 is formed between the receiving part 11 and the insertion part 21. The arc-assisted self-fusion weld 40 is an alloy layer comprising non-ferrous metal elements on the receiving part 11, non-ferrous metal elements on the insertion part 21, and a third metal element. The third metal element is any one or more combinations of nickel, aluminum, and silicon. The brazing filler metal forming the nickel element in the arc-assisted self-fusion weld 40 is a nickel-based brazing filler metal with a nickel percentage greater than or equal to 60%.

[0080] In this embodiment, an arc-fired self-fusion weld 40 is formed between the end face of the inner receiving portion 11 of the first component 1 and the outer peripheral wall of the second component 2. However, the present invention does not limit this in any way. In other embodiments, an arc-fired self-fusion weld 40 may also be formed between the end face of the insertion portion 21 of the second component 2 and the inner peripheral wall of the first component 1, such as... Figure 19 As shown. Alternatively, in other embodiments, an arc self-fusion weld 40 may be formed at the end face of the receiving portion 11 and the end face of the insertion portion 21, respectively, as shown. Figure 20 As shown.

[0081] In the dissimilar metal welding structure provided in this embodiment, the addition of a third metallic element can effectively improve the hot cracks and penetration cracks in the arc self-fusion weld 40, thereby improving the connection strength and pressure resistance of the weld.

[0082] Similar to Embodiment 1, to further improve the connection strength between the first component 1 and the second component 2, a brazing layer 30 (e.g., ...) can be formed in the assembly gap between the receiving part 11 and the insertion part 21. Figure 18 (As shown), and the length L1 of the brazing layer 30 is greater than or equal to the larger of 0.05Φ and 2.5mm, where Φ is the diameter of the hole at the receiving part. The brazing layer is formed by welding tin bronze brazing filler or brazing filler with a liquidus temperature below 920℃.

[0083] Similarly, the non-ferrous metal forming the receiving part 11 can be carbon steel or alloy steel with iron as the base material; the non-ferrous metal forming the insertion part 21 can be any one or more combinations of aluminum, aluminum alloy, copper or copper alloy.

[0084] In this embodiment, both the first component 1 and the second component 2 are hollow tubular fittings. However, this utility model does not impose any limitations on this. In other embodiments, the first component is a hollow container made of non-ferrous metal, with a receiving portion formed at the connecting hole on the hollow container, and the second component is a hollow tubular fitting. Alternatively, the first component is a hollow tubular fitting, and the second component is an end cap or end plate.

[0085] In summary, the dissimilar metal welding structure provided by this utility model employs laser welding for through-welding between non-ferrous and non-ferrous metals. During assembly, a non-ferrous metal insert in the second component is inserted into the non-ferrous metal receiving part in the first component. This arrangement ensures that during welding, the laser beam only irradiates the outer peripheral wall of the non-ferrous metal receiving part, and not the highly reflective non-ferrous metal insert. The low reflectivity of the non-ferrous metal receiving part allows it to absorb a large amount of laser beam energy. The heat penetrates the receiving part radially and partially melts the peripheral wall of the insert to form a molten pool, effectively solving the problem of laser welding difficulties caused by the extremely high and unstable reflectivity of non-ferrous metals. Compared to the loosely structured brazed layer formed by metallurgical diffusion dissolution, the laser-penetrating weld is a through-weld structure formed by the melting of dissimilar metal base materials and the recrystallization of elements through homogeneous epitaxy. This weld is not only dense and has high connection strength, but also exhibits excellent performance in terms of plasticity, toughness, and corrosion resistance. In addition, laser welding is not only highly efficient, but the welding heat does not affect the grain size of the second component, ensuring that the second component still has excellent connection strength and pressure resistance after welding.

[0086] Furthermore, the dissimilar metal welding structure provided by this utility model, based on laser-penetrated weld seam, employs brazing to form a brazing layer in the assembly gap between the receiving part and the insertion part, thereby further improving the welding strength of dissimilar metals.

[0087] Although the present invention has been disclosed above by way of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of protection claimed in the claims.

Claims

1. A dissimilar metal welded structure, characterized in that, include: The first component has a hollow receiving part made of non-ferrous metal; The second component includes a plug-in part made of non-ferrous metal, which is inserted into a receiving part on the first component and the overlapping area of ​​the two components forms a socket area. Wherein, a laser-penetrating weld formed by laser welding or laser wire feeding is formed on the peripheral wall of the receiving part in the socket area. The laser-penetrating weld penetrates the peripheral wall of the receiving part radially and extends into the peripheral wall of the insertion part of the second component, and the axial distance L from the laser-penetrating weld to the end face of the receiving part is ≥0.

2. The dissimilar metal welded structure according to claim 1, characterized in that, On the peripheral wall of the receiving part of the socket area, the number of laser-penetrated welds is one or more.

3. The dissimilar metal welded structure according to claim 2, characterized in that, The end face of the insertion part extends into the receiving part, and two laser-penetrating welds are formed on the socket area at both ends of the outer peripheral wall of the receiving part.

4. The dissimilar metal welded structure according to claim 1, characterized in that, A brazing layer is formed in the assembly gap between the receiving part and the insertion part, and the length L1 of the brazing layer is greater than or equal to the larger of 0.05Φ and 2.5mm, where Φ is the diameter of the hole at the receiving part.

5. The dissimilar metal welded structure according to claim 4, characterized in that, The brazing layer is an alloy layer formed by welding tin bronze brazing filler or brazing filler with a liquidus temperature below 920°C.

6. The dissimilar metal welded structure according to claim 4, characterized in that, At the socket area of ​​the insertion part and the receiving part, an exhaust hole is formed on the tube wall of the insertion part, which communicates with the inner cavity of the second component and is used to discharge brazing gas.

7. The dissimilar metal welded structure according to claim 1, characterized in that, The non-ferrous metal is carbon steel or alloy steel, and the non-ferrous metal is any one or more combinations of aluminum, aluminum alloy, copper, or copper alloy.

8. The dissimilar metal welded structure according to claim 1, characterized in that, Both the first and second components are hollow tubular fittings; Alternatively, the first component is a hollow container made of non-ferrous metal, with a receiving part formed at the connection hole on the hollow container, and the second component is a hollow tube; Alternatively, the first component may be a hollow tube, and the second component may be an end cap or an end plate.

9. A dissimilar metal welded structure, characterized in that, include: The first component has a hollow receiving part made of non-ferrous metal; The second component includes a connector made of non-ferrous metal, the receiving part being inserted into the receiving part of the first component; An arc-fused self-fusion weld is formed between the receiving part and the insert part. The arc-fused self-fusion weld is an alloy layer comprising non-ferrous metal elements on the receiving part, non-ferrous metal elements on the insert part, and a third metal element. The third metal element is any one or more combinations of nickel, aluminum, and silicon. The brazing filler metal that forms nickel in the arc-fused self-fusion weld is a nickel-based brazing filler metal with a nickel percentage of 60% or more.

10. The dissimilar metal welded structure according to claim 9, characterized in that, A brazing layer is formed in the assembly gap between the receiving part and the insertion part, and the length L1 of the brazing layer is greater than or equal to the larger of 0.05Φ and 2.5mm, where Φ is the diameter of the hole at the receiving part; The brazing layer is formed by welding tin bronze brazing material or brazing material with a liquidus temperature below 920°C.

11. A refrigeration component, characterized in that, Includes the dissimilar metal welded structure as described in any one of claims 1 to 10.

12. The refrigeration component according to claim 11, characterized in that, The refrigeration component also includes a connecting pipe made of non-ferrous metal, at least one end of which is provided with the dissimilar metal welding structure, and at least one end of the connecting pipe is welded to the first component in the dissimilar metal welding structure.

13. A refrigeration system, characterized in that, It includes the dissimilar metal welded structure as described in any one of claims 1 to 10; or, it includes the refrigeration component as described in claim 11 or 12.

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