Brazing filler metal, welding structure, preparation method of welding structure, compressor, pipeline of compressor and air conditioner

Abstract

The invention provides brazing filler metal, a welding structure, a preparation method of the welding structure, a compressor, a pipeline of the compressor and an air conditioner, relates to the technical field of compressors, and aims to solve the problems of low welding efficiency and low welding seam strength in related technologies. The brazing filler metal is applied to induction brazing of a compressor pipeline and comprises, by mass, 80-90 parts of copper, 5-10 parts of phosphorus, 1-5 parts of manganese and 0.5-5 parts of iron. According to the brazing filler metal provided by the invention, Fe and Mn synergistically improve the resistivity, iron can refine grains, and hysteresis loss during high-frequency heating is reduced. Under the same experiment condition, the Mn + Fe combination enables the resistivity improvement effect to be about 30% higher than that of single addition.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and more particularly, to a filler metal, a welding structure and a preparation method thereof, a compressor and its pipeline, and an air conditioner. Background Art

[0002] Currently, the welding of the connecting pipeline of an air conditioner compressor mainly adopts manual flame brazing technology. Workers use phosphorus copper welding rods for welding. However, conventional phosphorus copper welding rods have low heating efficiency, unstable welding quality, and low weld strength during the welding process. Summary of the Invention

[0003] The present invention aims to solve at least the problems of low welding efficiency and low weld strength existing in the related art.

[0004] To this end, in the first aspect of the present invention, a filler metal is provided, which is applied to the induction brazing of a compressor pipeline. By mass fraction, the filler metal comprises the following components: 80 parts to 90 parts of copper, 5 parts to 10 parts of phosphorus, 1 part to 5 parts of manganese, and 0.5 part to 5 parts of iron.

[0005] The filler metal provided by the present invention is applied to the induction brazing of a compressor pipeline, especially high-frequency induction brazing. During induction brazing, the filler metal can be inductively heated and melted to realize the connection between two adjacent compressor pipelines. The filler metal comprises copper element and phosphorus element, which are the base materials. On this basis, the filler metal further comprises manganese element and / or iron element. The addition of manganese element is to improve the joint strength and hardness, inhibit grain boundary brittleness, and improve high-temperature performance. The addition of manganese element can also increase the resistivity, inhibit the growth of Cu (copper) grains, and reduce the high-frequency eddy current loss. Therefore, during the high-frequency induction brazing process, the melting time can be reduced and the welding efficiency can be improved. Iron element can refine grains, improve mechanical strength, and enhance corrosion resistance. Based on the 4s electron scattering effect of Fe, Fe (iron) and Mn (manganese) synergistically increase the resistivity. Iron can also refine grains and reduce the hysteresis loss during high-frequency heating. Under the same experimental conditions, the Mn+Fe combination can increase the resistivity by about 30% more than that of adding alone.

[0006] In some technical solutions, optionally, the manganese is 1 part to 3 parts; the iron is 0.5 part to 2 parts.

[0007] In some technical solutions, optionally, the mass fraction ratio of Mn:Fe is greater than or equal to 2:1 and less than or equal to 3:1, forming a MnFe2O4 (manganese ferrite) spinel phase, and the resistivity increase is the most significant; excessive Fe will cause an increase in the brittle phase of Fe2P (iron phosphide), reducing the joint toughness; excessive Mn will cause lattice distortion saturation, and the resistivity increase amplitude will decrease.

[0008] In some technical solutions, optionally, the filler metal further comprises the following component: 0.5 part to 4 parts of nickel.

[0009] In this technical solution, Ni (nickel) forms an infinite solid solution with Cu, significantly improving the creep resistance of the solder at high temperatures (300°C to 600°C), and is suitable for the high-temperature working environment of compressor pipelines. In addition, Ni can inhibit the high-temperature diffusion of Mn / Fe elements at high temperatures, stabilize the resistivity of the solder ring, and thus increase the heating rate. Optionally, the amount of nickel is 0.5 to 2 parts.

[0010] In some technical solutions, optionally, the solder further includes the following components: 0.5 to 4 parts of tin.

[0011] In this technical solution, the tin element can reduce the surface tension of the liquid solder ring, improve wettability and fluidity, fill more evenly, and thus increase the joint strength. In addition, Sn (tin) forms a low-melting eutectic phase with Cu, reducing the solidus temperature of the solder, and thus reducing the thermal damage to the substrate. Optionally, the amount of tin is 0.5 to 2 parts.

[0012] In some technical solutions, optionally, the mass ratio of Ni to Sn is greater than or equal to 1:1 and less than or equal to 2:1. Excessive Sn will cause a decrease in resistivity, mainly because the ρ of Sn is relatively low; excessive Ni will increase the melting point, which is not conducive to rapid soldering.

[0013] In some technical solutions, optionally, the solder further includes rare earth elements, 0.01 to 0.05 parts.

[0014] In this technical solution, rare earth elements can purify the molten solder, adsorb oxygen / sulfur impurities, reduce pore defects; refine grains, improve the impact toughness of the joint, and the formed rare earth oxide film enhances corrosion resistance. In addition, rare earth elements can also increase the thermal conductivity of the solder, promote the uniformity of high-frequency induction heating, reduce local overheating, and thus improve the welding efficiency.

[0015] In some technical solutions, optionally, the rare earth elements include at least one of lanthanum element and cerium element.

[0016] In this technical solution, both lanthanum element and cerium element can react with impurities such as O (oxygen) and S (sulfur) in the molten solder to form high-melting rare earth oxides (La2O3, lanthanum trioxide) and sulfides (Ce2S3, cerium trisulfide), reducing pore defects. The 4f electron layer structure of lanthanum element and cerium element increases electron scattering, increases the resistivity of the solder, and is more suitable for the high-frequency skin effect.

[0017] In some technical solutions, optionally, the mass fraction of silver element in the solder is 0.

[0018] In this technical solution, the addition of Ag may reduce the resistivity of the solder, which is not conducive to the induction heating efficiency. Therefore, the solder of this application does not contain silver elements, has a higher resistivity, is more easily heated by high-frequency induction, and improves the thermal efficiency.

[0019] In some technical solutions, optionally, the amount of copper is 80 parts to 85 parts, or 85 parts to 90 parts, depending on the specific situation, and the amount of phosphorus is 5 parts to 7 parts, or 7 parts to 10 parts, depending on the specific situation.

[0020] The second aspect of the present invention provides a welding structure, which is made of the solder provided by any one of the technical solutions in the first aspect of the present invention.

[0021] In some technical solutions, optionally, the welding structure includes one of the following: welding rod, welding ring, welding wire or welding strip.

[0022] In some technical solutions, optionally, when the welding structure is a welding ring, along the axial direction of the welding ring, the welding ring includes an upper end face and a lower end face that are oppositely arranged. Both the upper end face and the lower end face are flat surfaces. The welding ring further includes an inner side face and an outer side face connecting the upper end face and the lower end face. An arc chamfer structure is included between any two adjacent faces.

[0023] In this technical solution, the shape of the welding ring is a flat ring. The chamfer can reduce the surface tension of the molten welding ring at the corners, promote the uniform spreading of the liquid metal, and avoid the flow stagnation or weld discontinuity caused by right angles. In addition, the arc chamfer can optimize the distribution of high-frequency induction current, avoid local overheating caused by too high current density at the sharp corners, and make the heating more uniform. When the welding ring is intercepted along the radial direction, the cross section of the welding ring is approximately rectangular.

[0024] In some technical solutions, optionally, the arc length of the arc chamfer structure is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

[0025] In this technical solution, if the arc length of the arc chamfer structure is too small, the improvement effect on fluidity and stress is limited. If the arc length is too large, the structural strength of the welding ring decreases and it is easily deformed during assembly. Therefore, it is controlled within 0.1 mm to 0.5 mm, optionally 0.1 mm, 0.3 mm or 0.5 mm.

[0026] In some technical solutions, optionally, when the welding structure is a welding ring, along the radial direction of the welding ring, the thickness of the welding ring is greater than or equal to 1.0 mm and less than or equal to 2.0 mm.

[0027] In this technical solution, a thickness of the welding ring greater than or equal to 1.0 mm ensures sufficient solder to fill the weld and avoids incomplete penetration; less than or equal to 2.0 mm prevents excessive solder from overflowing. Optionally, the thickness of the welding ring is 1.0 mm, 1.5 mm or 2.0 mm.

[0028] In some technical solutions, optionally, when the welding structure is a welding ring, along the axial direction of the welding ring, the height of the welding ring is greater than or equal to 1.5 mm and less than or equal to 5.0 mm.

[0029] In this technical solution, a height of the welding ring greater than or equal to 1.5 mm facilitates automatic grasping; a height less than or equal to 5.0 mm prevents the welding ring from shaking on the pipeline. Optionally, the height of the welding ring is equal to 1.5 mm, 3 mm or 5 mm.

[0030] In some technical solutions, optionally, when the welding structure is a welding ring, the inner diameter of the welding ring is greater than or equal to 13 mm and less than or equal to 23 mm.

[0031] In this technical solution, controlling the inner diameter of the welding ring between 13 mm and 23 mm can cover the outer diameter of common compressor copper pipes to ensure interference fit. Optionally, the inner diameter of the welding ring is greater than or equal to 15 mm and less than or equal to 20 mm.

[0032] In the welding structure of the present application, phosphorus reacts with copper at high temperature to form Cu3P (copper phosphide) eutectic and release P2O5 (phosphorus pentoxide) gas, autonomously removing metal surface oxides; the oxidation products of manganese and iron form a dense protective layer to prevent the pipeline from being re-oxidized, nickel and tin act synergistically to reduce the surface tension of the molten alloy, and trace rare earth elements further purify the molten pool by adsorbing oxygen / sulfur impurities. This composite design enables the welding ring to spontaneously complete the processes of deoxidation, anti-oxidation and wetting spreading during induction heating, completely replacing the chemical auxiliary function of traditional soldering fluxes, that is, the welding ring of the present application does not require a soldering flux during the entire welding process.

[0033] The third aspect of the present invention provides a preparation method of a welding structure, including: melting, casting and heat-treating the raw materials of the welding structure to obtain the welding structure; wherein, by mass, the raw materials of the welding structure include the following components: 80 parts to 90 parts of copper, 5 parts to 10 parts of phosphorus, 1 part to 5 parts of manganese, and 0.5 parts to 5 parts of iron.

[0034] In the preparation method of the welding structure provided by the present invention, the raw materials include manganese element and iron element. The manganese element is used to improve the joint strength and hardness, inhibit grain boundary brittleness, and improve high-temperature performance. The addition of the manganese element can also increase the resistivity, inhibit the growth of Cu grains, and reduce high-frequency eddy current loss, thereby reducing the melting time and improving the welding efficiency during high-frequency induction brazing. The iron element can refine grains, improve mechanical strength, and enhance corrosion resistance. Based on the 4s electron scattering effect of Fe, Fe and Mn synergistically increase the resistivity, and iron can also refine grains and reduce the hysteresis loss during high-frequency heating. Under the same experimental conditions, the Mn+Fe combination makes the resistivity increase effect about 30% higher than that of adding alone.

[0035] In some technical solutions, optionally, the raw materials of the welding structure further include 0.5 to 4 parts of nickel.

[0036] In this technical solution, Ni forms an infinite solid solution with Cu, significantly improving the creep resistance of the solder at high temperatures (300°C to 600°C), and is suitable for the high-temperature working environment of the compressor pipeline. In addition, Ni can inhibit the high-temperature diffusion of Mn / Fe elements at high temperatures, stabilize the resistivity of the solder ring, and thus increase the heating rate. Optionally, 0.5 to 2 parts of nickel.

[0037] In some technical solutions, optionally, the raw materials of the welding structure further include 0.5 to 4 parts of tin.

[0038] In this technical solution, the tin element can reduce the surface tension of the liquid solder ring, improve the wettability and fluidity, fill more evenly, and thus increase the joint strength. In addition, Sn forms a eutectic phase with low melting point with Cu, reducing the solidus temperature of the solder and reducing the thermal damage to the substrate. Optionally, 0.5 to 2 parts of tin.

[0039] In some technical solutions, optionally, the raw materials of the welding structure further include rare earth elements.

[0040] In this technical solution, rare earth elements can purify the molten solder, adsorb oxygen / sulfur impurities, reduce pore defects; refine the grains, improve the impact toughness of the joint; and form a rare earth oxide film to enhance the corrosion resistance. In addition, rare earth elements increase the thermal conductivity of the solder, promote the uniformity of high-frequency induction heating, reduce local overheating, and thus improve the welding efficiency. The rare earth elements include at least one of lanthanum element and cerium element.

[0041] In some technical solutions, optionally, in the heat treatment step, the holding temperature is greater than or equal to 500°C and less than or equal to 600°C, and the holding time is greater than or equal to 2 h and less than or equal to 3 h.

[0042] In this technical solution, precise control of temperature and time can stably form a Mn / Fe-Cu solid solution, increase the resistivity, and thus improve the welding efficiency. Optionally, the holding temperature is greater than or equal to 520°C and less than or equal to 580°C, such as 520°C, 540°C, 560°C or 580°C. The holding time is equal to 2 h, 2.5 h or 3 h.

[0043] The fourth aspect of the present invention provides a compressor pipeline, including: a first pipe fitting having a first welding end face; a second pipe fitting having a second welding end face docked with the first welding end face; a welding joint for connecting the first welding end face and the second welding end face; wherein, the welding joint is formed by induction heating and melting and then solidifying the welding structure of any one of the technical solutions in the second aspect of the present application, or the welding joint is formed by induction heating and melting and then solidifying the welding structure prepared by the preparation method of the welding structure of any one of the technical solutions in the third aspect of the present application.

[0044] The compressor pipeline provided by this application has excellent welding performance, high strength, high sealing performance and corrosion resistance. Specifically, Mn is dissolved in the copper matrix to increase the dislocation resistance, and Fe and P (phosphorus) form fine Fe2P phases to inhibit grain boundary slip, thereby improving the welding strength; Sn reduces the surface tension of the liquid solder ring, promotes the molten metal to fully fill the microscopic gaps of the weld, thereby improving the sealing performance of the welded joint, and the synergistic protection of nickel and rare earth elements improves the corrosion resistance. Ni forms a corrosion-resistant barrier at the grain boundary, and rare earths adsorb impurities and form a dense rare earth oxide film to block the penetration of corrosive media.

[0045] The fifth aspect of the present invention provides a compressor, including the compressor pipeline of the technical solution of the fourth aspect of the present invention.

[0046] The sixth aspect of the present invention provides an air conditioner, including the compressor of the technical solution of the fifth aspect of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0048] Figure 1 Figure 1 shows one of the structural schematic diagrams of the welding structure of an embodiment of this application;

[0049] Figure 2 Figure 2 shows another structural schematic diagram of the welding structure of an embodiment of this application;

[0050] Figure 3 Figure 3 shows yet another structural schematic diagram of the welding structure of an embodiment of this application;

[0051] Figure 4 Figure 4 shows the structural schematic diagram of a compressor of this application;

[0052] Figure 5 Figure 5 shows the structural schematic diagram of an air conditioner of this application;

[0053] Figure 6 Figure 6 shows the preparation flow chart of the preparation method of the welding structure of an embodiment of this application.

[0054] Wherein, Figures 1 to 5 The corresponding relationship between the reference numerals in the drawings and the component names is as follows:

[0055] 1 is an air conditioner, 12 is a compressor, 122 is a compressor pipeline, 1222 is a first pipe fitting, 1224 is a second pipe fitting, 1226 is a welded joint, 13 is a welding structure, 132 is a solder ring, 133 is an upper end face, 134 is a lower end face, 135 is an inner side face, 136 is an outer side face, 137 is an arc chamfer structure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0056] In order to more clearly understand the above-mentioned objects, features and advantages of the present application, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.

[0057] In the following description, many specific details are set forth in order to fully understand the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0058] An embodiment of the first aspect of the present invention provides a filler metal, which is applied to induction brazing of compressor pipelines. By mass fraction, the filler metal includes the following components: 80 to 90 parts of copper, 5 to 10 parts of phosphorus, 1 to 5 parts of manganese, and 0.5 to 5 parts of iron.

[0059] The filler metal provided by the present invention is applied to induction brazing of compressor pipelines, especially high-frequency induction brazing. During induction brazing, the filler metal can be inductively heated and melted to achieve the connection between two adjacent compressor pipelines. The filler metal includes copper element and phosphorus element, and the copper element and phosphorus element are base materials. On this basis, the filler metal also includes manganese element and / or iron element. Adding manganese element is to improve the joint strength and hardness, inhibit grain boundary brittleness, and improve high-temperature performance. The addition of manganese element can also increase the resistivity, inhibit the growth of Cu grains, and reduce the high-frequency eddy current loss, so as to reduce the melting time and improve the welding efficiency during high-frequency induction brazing. Iron element can refine grains, improve mechanical strength, and enhance corrosion resistance. Based on the 4s electron scattering effect of Fe, Fe and Mn synergistically increase the resistivity, and iron can also refine grains and reduce the hysteresis loss during high-frequency heating. Under the same experimental conditions, the Mn+Fe combination makes the resistivity increase effect about 30% higher than that of adding alone.

[0060] In some embodiments, optionally, the manganese is 1 to 3 parts; the iron is 0.5 to 2 parts.

[0061] In some embodiments, optionally, the mass fraction ratio of Mn:Fe is greater than or equal to 2:1 and less than or equal to 3:1 to form the MnFe2O4 spinel phase, and the resistivity increase is the most significant; excessive Fe will cause an increase in the Fe2P brittle phase and reduce the joint toughness; excessive Mn will cause lattice distortion saturation and the resistivity increase amplitude will decrease.

[0062] In some embodiments, optionally, the filler metal further includes the following component: 0.5 to 4 parts of nickel.

[0063] In this embodiment, Ni and Cu form an infinite solid solution, significantly improving the creep resistance of the solder at high temperatures (300°C to 600°C), and is suitable for the high-temperature working environment of the compressor pipeline. In addition, Ni can inhibit the high-temperature diffusion of Mn / Fe elements at high temperatures, stabilize the resistivity of the solder ring, and thus increase the heating rate. Optionally, the amount of nickel is 0.5 to 2 parts.

[0064] In some embodiments, optionally, the solder further comprises the following components: 0.5 to 4 parts of tin.

[0065] In this embodiment, the tin element can reduce the surface tension of the liquid solder ring, improve the wettability and fluidity, fill more evenly, and thus increase the joint strength. In addition, Sn and Cu form a eutectic phase with a low melting point, reducing the solidus temperature of the solder, and thus reducing the thermal damage to the substrate. Optionally, the amount of tin is 0.5 to 2 parts.

[0066] In some embodiments, optionally, the mass ratio of Ni to Sn is greater than or equal to 1:1 and less than or equal to 2:1. Excessive Sn will cause a decrease in resistivity, mainly because the ρ of Sn is relatively low; excessive Ni will increase the melting point, which is not conducive to rapid soldering.

[0067] In some embodiments, optionally, the solder further comprises rare earth elements, 0.01 to 0.05 parts.

[0068] In this embodiment, the rare earth elements can purify the molten solder, adsorb oxygen / sulfur impurities, reduce pore defects; refine the grains, improve the impact toughness of the joint, and form a rare earth oxide film to enhance the corrosion resistance. In addition, the rare earth elements can also increase the thermal conductivity of the solder, promote the uniformity of high-frequency induction heating, reduce local overheating, and thus improve the welding efficiency.

[0069] In some embodiments, optionally, the rare earth elements include at least one of lanthanum element and cerium element.

[0070] In this embodiment, both lanthanum element and cerium element can react with impurities such as O and S in the molten solder to form rare earth oxides with high melting points (La2O3) and sulfides (Ce2S3), reducing pore defects. The 4f electron layer structure of lanthanum element and cerium element increases electron scattering, increases the resistivity of the solder, and is more suitable for the high-frequency skin effect.

[0071] In some embodiments, optionally, the mass fraction of silver element in the solder is 0.

[0072] In this embodiment, the addition of Ag may reduce the resistivity of the solder, which is not conducive to the induction heating efficiency. Therefore, the solder of the present application does not contain silver element, has a higher resistivity, is more easily heated by high-frequency induction, and improves the thermal efficiency.

[0073] In some embodiments, optionally, the amount of copper is 80 to 85 parts, or 85 to 90 parts, depending on the specific situation, and the amount of phosphorus is 5 to 7 parts, or 7 to 10 parts, depending on the specific situation.

[0074] It should be noted that the total mass fraction of copper, phosphorus, manganese, iron, nickel, tin and rare earth elements in the solder of the present application is 100 parts.

[0075] As Figure 2 shown, in the second aspect of the present invention, an embodiment provides a welding structure 13, which is made of the solder provided by any one of the embodiments in the first aspect of the present invention.

[0076] In some embodiments, optionally, the welding structure 13 includes one of the following: a welding rod, a welding ring 132, a welding wire or a welding strip.

[0077] As Figure 1 , Figure 2 and Figure 3 shown, in some embodiments, optionally, when the welding structure 13 is a welding ring 132, along the axial direction of the welding ring 132, the welding ring 132 includes an upper end face 133 and a lower end face 134 which are oppositely arranged. Both the upper end face 133 and the lower end face 134 are flat surfaces. The welding ring 132 further includes an inner side face 135 and an outer side face 136 connecting the upper end face 133 and the lower end face 134, and an arc chamfer structure 137 is included between any two adjacent faces.

[0078] In this embodiment, the outer shape of the welding ring 132 is a flat ring shape. The chamfer can reduce the surface tension of the molten welding ring at the corners, promote the uniform spreading of the liquid metal, and avoid the flow stagnation or weld discontinuity caused by right angles. In addition, the arc chamfer can optimize the distribution of the high-frequency induction current, avoid local overheating caused by too high current density at the sharp corners, and make the heating more uniform. When the welding ring 132 is intercepted along the radial direction, the cross-section of the welding ring 132 is approximately rectangular.

[0079] Among them, Figure 1 and Figure 2 the dotted lines in are both symmetry lines.

[0080] In some embodiments, optionally, the arc length of the arc chamfer structure 137 is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

[0081] In this embodiment, if the arc length of the arc chamfer structure 137 is too small, the improvement effect on fluidity and stress is limited. If the arc length is too large, the structural strength of the welding ring 132 decreases and it is easy to deform during assembly. Therefore, it is controlled within 0.1 mm to 0.5 mm, optionally 0.1 mm, 0.3 mm or 0.5 mm.

[0082] In some embodiments, optionally, as Figure 3As shown, in the case where the welding structure 13 is a welding ring 132 , along the radial direction of the welding ring 132 , the thickness M of the welding ring 132 is greater than or equal to 1.0 mm and less than or equal to 2.0 mm.

[0083] In this embodiment, the thickness M of the solder ring 132 is greater than or equal to 1.0 mm to ensure that sufficient solder fills the weld and avoids incomplete penetration; less than or equal to 2.0 mm to prevent excess solder from overflowing. Optionally, the thickness M of the solder ring 132 is 1.0 mm, 1.5 mm or 2.0 mm.

[0084] In some embodiments, optionally, when the welding structure 13 is a welding ring 132 , along the axial direction of the welding ring 132 , a height D of the welding ring 132 is greater than or equal to 1.5 mm and less than or equal to 5.0 mm.

[0085] In this embodiment, the height D of the welding ring 132 is greater than or equal to 1.5 mm to facilitate automatic grasping, and less than or equal to 5.0 mm to prevent the welding ring 132 from shaking on the pipeline. Optionally, the height D of the welding ring 132 is equal to 1.5 mm, 3 mm or 5 mm.

[0086] In some embodiments, optionally, when the welding structure 13 is a welding ring 132, the inner diameter R of the welding ring 132 is greater than or equal to 13 mm and less than or equal to 23 mm. Figure 3 The middle dashed line L is the center axis of the welding ring 132 .

[0087] In this embodiment, the inner diameter R of the welding ring 132 is controlled between 13 mm and 23 mm to cover the outer diameter of the common copper tube of the compressor 12 and ensure interference fit. Optionally, the inner diameter R of the welding ring 132 is greater than or equal to 15 mm and less than or equal to 20 mm.

[0088] In the welding structure 13 of the present application, phosphorus reacts with copper at high temperature to form Cu3P eutectic and release P2O5 gas, which autonomously removes oxides on the metal surface; the oxidation products of manganese and iron form a dense protective layer to prevent the pipeline from being oxidized again, and nickel and tin work together to reduce the surface tension of the molten alloy, while trace rare earth elements further purify the molten pool by adsorbing oxygen / sulfur impurities. This composite design enables the welding ring 132 to spontaneously complete the deoxidation, anti-oxidation and wetting process during induction heating, completely replacing the chemical auxiliary function of traditional flux, that is, the welding ring 132 of the present application does not require flux during the entire welding process.

[0089] like Figure 6 As shown, the third aspect of the present invention provides a method for preparing a welding structure, comprising:

[0090] S102: Smelt, cast, and heat-treat the raw materials of the welded structure to obtain the welded structure. Among them, by mass fraction, the raw materials of the welded structure include the following components: 80 to 90 parts of copper, 5 to 10 parts of phosphorus, 1 to 5 parts of manganese, and 0.5 to 5 parts of iron.

[0091] For the preparation method of the welded structure provided by the present invention, the raw materials include manganese element and iron element. The manganese element is used to improve the joint strength and hardness, inhibit the brittleness of grain boundaries, and improve the high-temperature performance. The addition of manganese element can also increase the resistivity, inhibit the growth of Cu grains, and reduce the high-frequency eddy current loss, thereby reducing the melting time and improving the welding efficiency during high-frequency induction brazing. The iron element can refine the grains, improve the mechanical strength, and enhance the corrosion resistance. Based on the 4s electron scattering effect of Fe, Fe and Mn synergistically increase the resistivity, and iron can also refine the grains and reduce the hysteresis loss during high-frequency heating. Under the same experimental conditions, the Mn+Fe combination makes the resistivity increase effect about 30% higher than that of adding alone.

[0092] In some embodiments, optionally, the raw materials of the welded structure further include 0.5 to 4 parts of nickel.

[0093] In this embodiment, Ni forms an infinite solid solution with Cu, significantly improving the creep resistance of the solder at high temperatures (300°C to 600°C), and is suitable for the high-temperature working environment of compressor pipelines. In addition, Ni can inhibit the high-temperature diffusion of Mn / Fe elements at high temperatures, stabilize the resistivity of the solder ring, and thus increase the heating rate. Optionally, 0.5 to 2 parts of nickel.

[0094] In some embodiments, optionally, the raw materials of the welded structure further include 0.5 to 4 parts of tin.

[0095] In this embodiment, the tin element can reduce the surface tension of the liquid solder ring, improve the wettability and fluidity, fill more evenly, and thus improve the joint strength. In addition, Sn forms a eutectic phase with low melting point with Cu, reducing the solidus temperature of the solder and reducing the thermal damage of the base material. Optionally, 0.5 to 2 parts of tin.

[0096] In some embodiments, optionally, the raw materials of the welded structure further include rare earth elements.

[0097] In this embodiment, the rare earth elements can purify the molten solder, adsorb oxygen / sulfur impurities, and reduce pore defects; refine the grains, improve the impact toughness of the joint; and form a rare earth oxide film to enhance the corrosion resistance. In addition, the rare earth elements increase the thermal conductivity of the solder, promote the uniformity of high-frequency induction heating, reduce local overheating, and thus improve the welding efficiency. The rare earth elements include at least one of lanthanum element and cerium element.

[0098] In some embodiments, optionally, in the heat treatment step, the holding temperature is greater than or equal to 500 °C and less than or equal to 600 °C, and the holding time is greater than or equal to 2 h and less than or equal to 3 h.

[0099] In this embodiment, precise temperature and time control can stably form a Mn / Fe-Cu solid solution, increase the resistivity, and thus improve the welding efficiency. Optionally, the holding temperature is greater than or equal to 520 °C and less than or equal to 580 °C, such as 520 °C, 540 °C, 560 °C or 580 °C. The holding time is equal to 2 h, 2.5 h or 3 h.

[0100] As Figure 4 shown, the fourth aspect of the present invention provides a compressor pipeline 122, including: a first pipe fitting 1222 having a first welding end face; a second pipe fitting 1224 having a second welding end face that docks with the first welding end face; a welding joint 1226 for connecting the first welding end face and the second welding end face; wherein, the welding joint 1226 is formed by induction heating and melting and then solidifying the welding structure 13 of any one of the embodiments of the second aspect of the present application, or the welding joint 1226 is formed by induction heating and melting and then solidifying the welding structure 13 prepared by the preparation method of the welding structure of any one of the embodiments of the third aspect of the present application.

[0101] For the compressor pipeline 122 provided by the present application, the welding joint 1226 has excellent welding performance, high strength, high sealing performance and corrosion resistance. Specifically, Mn is dissolved in the copper matrix to increase the dislocation resistance, and Fe and P form fine Fe2P phases to inhibit grain boundary slip, thereby improving the welding strength; Sn reduces the surface tension of the liquid solder ring and promotes the full filling of the microscopic gaps in the weld by the molten metal, thereby improving the sealing performance of the welding joint 1226, and the synergistic protection of nickel and rare earth elements improves the corrosion resistance. Ni forms a corrosion-resistant barrier at the grain boundary, and rare earths adsorb impurities and form a dense rare earth oxide film to block the penetration of corrosive media.

[0102] The fifth aspect of the present invention provides a compressor 12, including the compressor pipeline 122 of the embodiment of the fourth aspect of the present invention.

[0103] As Figure 5 shown, the sixth aspect of the present invention provides an air conditioner 1, including the compressor 12 of the embodiment of the fifth aspect of the present invention.

[0104] Another embodiment of the present invention provides a phosphorus copper solder ring for high-frequency induction brazing of compressor pipelines and a preparation method thereof. The welding of the connecting pipelines of air-conditioning compressors mainly uses manual flame brazing technology, and manual use of phosphorus copper electrodes for welding has low efficiency and unstable welding quality. The present invention provides a phosphorus copper solder ring for high-frequency induction brazing of compressor pipelines and a preparation method thereof. Through optimizing the composition design and preparation process, the solder ring has excellent welding performance, high strength, high sealing performance and corrosion resistance. The phosphorus copper solder ring of the present invention is suitable for high-frequency induction brazing of compressor pipelines. Under the condition of high-frequency induction heating, the solder ring material can be quickly and uniformly heated to form a high-strength welded joint, has excellent corrosion resistance and electrical conductivity, and is used to replace the phosphorus copper electrodes for manual flame brazing, thereby improving the welding quality and efficiency. The solder ring of the present invention does not need to use a flux, has excellent environmental protection performance, and has a wide application prospect.

[0105] Specifically, the composition of the phosphorus copper solder ring for high-frequency induction brazing of compressor pipelines in this embodiment includes: copper (Cu) 80%-90%, phosphorus (P) 5%-7%, manganese (Mn) 1%-3%, iron (Fe) 0.5%-2%, nickel (Ni) 0.5%-2%, tin (Sn) 0.5%-2%, rare earth elements 0.01%-0.05%, and does not contain precious metal silver (Ag).

[0106] Optionally, the rare earth element is lanthanum or cerium.

[0107] This embodiment provides a preparation method of a phosphorus copper solder ring, which includes the following steps: melting, casting, heat treatment and machining into shape.

[0108] Optionally, the heat treatment temperature is 500°C - 600°C, and the heat preservation time is 2 - 3 hours.

[0109] Optionally, the solder ring does not require a flux.

[0110] Optionally, the shape of the solder ring is a flat ring.

[0111] Optionally, the cross-section of the solder ring is approximately rectangular, and the surface chamfer is 0.1 mm - 0.5 mm.

[0112] Optionally, the dimensions of the solder ring are: thickness 1.0 mm - 2.0 mm, height 1.5 mm - 5 mm, and inner diameter 13 mm - 23 mm.

[0113] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0114] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A solder, characterized in that: The induction brazing used for compressor pipelines comprises the following components by weight: 80 to 90 parts of copper, 5 to 10 parts of phosphorus, 1 to 5 parts of manganese and 0.5 to 5 parts of iron.

2. The solder according to claim 1, characterized in that The solder also includes the following components: 0.5 to 4 parts of nickel; and / or Tin 0.5 to 4 parts.

3. The solder according to claim 1, characterized in that The solder also includes: Rare earth elements, 0.01 to 0.05 parts.

4. The solder according to claim 3, characterized in that The rare earth element includes at least one of lanthanum and cerium.

5. The solder according to any one of claims 1 to 4, characterized in that The mass fraction of silver in the solder is 0.

6. A welding structure, characterized in that: The welded structure is made of the brazing material according to any one of claims 1 to 5.

7. The welding structure according to claim 6, characterized in that: The welding structure includes one of the following: a welding rod, a welding ring, a welding wire or a welding strip.

8. The welding structure according to claim 7, characterized in that: In the case where the welding structure is a welding ring, along the axial direction of the welding ring, the welding ring includes an upper end face and a lower end face that are relatively arranged, and the upper end face and the lower end face are both planes. The welding ring also includes an inner side face and an outer side face connecting the upper end face and the lower end face, and an arc chamfer structure is included between any two adjacent faces.

9. The welding structure according to claim 8, characterized in that: The arc length of the arc chamfered structure is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

10. The welding structure according to claim 7, characterized in that: In the case where the welding structure is a welding ring, Along the radial direction of the welding ring, the thickness of the welding ring is greater than or equal to 1.0 mm and less than or equal to 2.0 mm; and / or Along the axial direction of the welding ring, the height of the welding ring is greater than or equal to 1.5 mm and less than or equal to 5.0 mm; and / or The inner diameter of the welding ring is greater than or equal to 13 mm and less than or equal to 23 mm.

11. A method for preparing a welding structure, characterized in that: include: Melting, casting and heat treating the raw materials of the welded structure to obtain the welded structure; Wherein, the raw materials of the welding structure include the following components in parts by mass: 80 to 90 parts of copper, 5 to 10 parts of phosphorus, 1 to 5 parts of manganese and 0.5 to 5 parts of iron.

12. The method for preparing a welding structure according to claim 11, characterized in that: The raw materials of the welding structure also include the following components: 0.5 to 4 parts of nickel; and / or 0.5 to 4 parts of tin; and / or Rare earth elements, 0.01 to 0.05 parts.

13. The method for preparing a welding structure according to claim 11, characterized in that: In the heat treatment step, the insulation temperature is greater than or equal to 500° C. and less than or equal to 600° C., and the insulation time is greater than or equal to 2 hours and less than or equal to 3 hours.

14. A compressor pipeline, characterized in that: include: A first pipe member having a first welding end face; A second pipe member having a second welding end face connected to the first welding end face; A welding joint, used to connect the first welding end surface and the second welding end surface; The weld joint is formed by melting the weld structure according to any one of claims 6 to 10 by induction heating and solidifying, or the weld joint is formed by melting the weld structure according to any one of claims 11 to 13 by induction heating and solidifying.

15. A compressor, characterized in that: include: The compressor piping of claim 14.

16. An air conditioner, characterized in that: include: The compressor of claim 15.

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