High-frequency induction brazing method and device for aluminum-steel dissimilar metal of electrolytic cell anode structure

Abstract

The high-frequency induction brazing method for the aluminum-steel dissimilar metal of the electrolytic cell anode structure comprises the steps that a hollow annular connecting piece is arranged at the to-be-welded end of a steel bar, and the to-be-welded end of an aluminum bar can be inserted into the connecting piece; the to-be-welded areas of the steel bar and the aluminum bar and the connecting piece are subjected to deoxidation and sand blasting treatment; after a plurality of screws are fixed to the end, to be welded, of the treated steel bar, aluminum-based brazing filler metal is placed in the connecting piece, and the aluminum-based brazing filler metal comprises metal elements of Al, Cu, Mg, Si, La and Ce; after the to-be-welded end of the aluminum bar is inserted into the connecting piece, high-frequency electromagnetic induction heating coils are arranged around the to-be-welded areas of the steel bar and the aluminum bar; the steel claw is heated to the preset temperature through induction current generated by the high-frequency electromagnetic induction heating coil, the heating time is controlled to the preset time, aluminum side melting and steel side solid combination are achieved through the skin effect and the proximity effect, and the multi-face stable connector is formed.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of aluminum / steel dissimilar metal welding, and in particular to a method and device for high-frequency induction brazing of aluminum and steel dissimilar metals in an electrolytic cell anode structure. Background Art

[0002] With the development of the electrolytic aluminum industry, the joining technology of aluminum and steel dissimilar metals in the anode structure of electrolytic cells has become a key factor affecting electrolysis efficiency and equipment operational stability. However, the physical and chemical properties of aluminum and steel differ significantly, with melting points differing by approximately 800°C and thermal expansion coefficients differing by more than 2 times. Furthermore, their metallurgical compatibility is extremely poor. Direct welding easily forms brittle Fe-Al intermetallic compounds, Fe2Al5 and FeAl3, at the interface, resulting in low joint strength and susceptibility to cracking, severely restricting high-performance joining of dissimilar materials.

[0003] Challenges faced by traditional welding methods such as fusion welding and arc welding: premature melting of aluminum and insufficient melting of steel during fusion welding can easily lead to an excessively thick intermetallic compound (IMC) layer at the interface; although low-temperature brazing can inhibit IMC growth, it has problems such as poor wettability and insufficient joint strength. Summary of the Invention

[0004] The embodiments of the present application provide a method and device for high-frequency induction brazing of dissimilar metals of aluminum and steel in the anode structure of an electrolytic cell, which can significantly reduce the resistivity of the connection between the anode aluminum guide rod and the steel claw, improve the conductive efficiency and structural strength, while further improving the working efficiency of the fusion brazing and reducing the equipment investment cost.

[0005] The following technical solutions are adopted in the embodiments of the present application:

[0006] In a first aspect, an embodiment of the present application provides a method for high-frequency induction brazing of dissimilar metals of aluminum and steel in an electrolytic cell anode structure, comprising: providing an internal hollow annular connector at the end of a steel rod to be welded, the connector being capable of accommodating the insertion of the end of the aluminum rod to be welded; performing deoxidation and sandblasting treatment on the areas to be welded of the steel rod and the aluminum rod and the connector; after fixing a plurality of screws on the treated end of the steel rod to be welded, placing an aluminum-based brazing filler metal inside the connector, wherein the aluminum-based brazing filler metal includes Al, Cu, Mg, Si, La, and Ce metal elements; after inserting the end of the aluminum rod to be welded into the connector, arranging a high-frequency electromagnetic induction heating coil around the steel rod and the area to be welded of the aluminum rod; utilizing the induced current generated by the high-frequency electromagnetic induction heating coil to heat the steel claw to a preset temperature, controlling the heating time to a preset time, and utilizing the skin effect and the proximity effect to achieve melting of the aluminum side and solid-state bonding of the steel side to form a multi-faceted stable joint.

[0007] In this embodiment, the differences between aluminum and steel, such as their significant melting point difference and thermal expansion coefficient, are difficult to overcome with traditional welding methods. High-frequency induction brazing, however, leverages its heating precision and localized heating properties to effectively avoid the formation of brittle intermetallic compounds at the interface by connecting the molten aluminum side to the solid steel side. Traditional welding methods such as fusion welding and low-temperature brazing often result in long heating times and low joint strength. High-frequency induction brazing, however, achieves precise heating in a shorter time and forms a stable weld joint. This significantly improves work efficiency. Through a rational welding process, particularly the application of high-frequency induction heating at the aluminum-steel joint, the resistivity of the aluminum-steel joint can be effectively reduced, the conductivity of the electrolytic cell anode structure can be increased, and overall electrolysis efficiency and equipment stability can be improved. Compared to traditional welding equipment, high-frequency induction heating devices offer higher thermal efficiency and lower energy consumption, reducing energy consumption while improving production efficiency. This helps reduce overall equipment investment costs. High-frequency induction heating technology precisely controls the heating area and temperature, avoiding overheating and uneven heating issues common in traditional welding. This results in more consistent weld joint quality, meeting the demands of demanding engineering applications. By precisely controlling the heating process and selecting the right brazing filler metal, the mechanical properties of the joint can be effectively improved, especially the durability and strength of the connection area. Compared with traditional welding methods, welded joints have higher reliability and longer service life.

[0008] As an achievable embodiment, the method further includes: the method further includes: in terms of weight percentage, the aluminum-based brazing filler metal includes Al 80-85%, Cu 5-10%, Mg 1-3%, Si 3-6%, La 1%, and Ce 1%.

[0009] As a feasible implementation method, the deoxidation includes: using 400-grit coarse sandpaper to polish the areas to be welded of the steel rod and the aluminum rod to remove the surface oxide layer and scratches, polishing until the surface to be welded reveals a silvery-white metallic luster, and then further smoothing and flattening the surfaces to be welded of the steel plate and the aluminum rod.

[0010] As a feasible embodiment, the method further includes: weighing 80-85% Al, 5-10% Cu, 1-3% Mg, 3-6% Si, 1% La, and 1% Ce in percentage by weight, stirring them evenly and then melting them, cooling the molten metal liquid to set it, and obtaining an aluminum-based brazing filler metal for welding.

[0011] As a feasible implementation method, the stirring time of the aluminum-based solder is not less than 120 seconds; the melting temperature is 700-800°C, the melting time is 60-120 seconds, and the cooling method is room temperature molding.

[0012] As a feasible implementation, the number of the screws is 4, and the length is 2 cm. The 4 screws are evenly fixed in a circular array on the end portion to be welded of the steel rod and are located in the hollow structure of the connector.

[0013] As a feasible implementation method, the aluminum rod has a diameter of 5 cm and a length of 5 cm, the steel rod has a diameter of 5 cm and a length of 5 cm, and the length of the connecting piece provided on one side of the steel rod is 2 cm.

[0014] As a feasible implementation, the preset temperature is 700° C., and the preset time is 300 s.

[0015] As a feasible implementation method, the high-frequency electromagnetic induction heating coil is a hollow tube made of copper with a diameter of 8 cm.

[0016] In the second aspect, the embodiment of the present application also provides a high-frequency induction brazing device for dissimilar metals of aluminum and steel in the anode structure of an electrolytic cell, comprising: a connecting piece, which is arranged on the surface of the steel rod to be welded, and the connecting piece is an annular structure with a hollow interior, and the connecting piece can accommodate the insertion of the end of the aluminum rod to be welded; a plurality of screws are provided, which are evenly fixed in an annular array to the end of the steel rod to be welded, and are located in the hollow structure of the connecting piece; a high-frequency electromagnetic induction heating coil is arranged on the peripheral side of the area to be welded of the steel rod and the aluminum rod, and is used to heat the steel rod and the aluminum rod, wherein an aluminum-based brazing material layer is provided between the ends to be welded of the steel rod and the aluminum rod, the interior of the connecting piece and the peripheral side of the aluminum rod.

[0017] In this embodiment, the tight fixing design of the connector and screws effectively prevents relative displacement of the aluminum and steel rods during welding, thereby ensuring the stability and precision of the welded joint. The hollow ring connector design provides precise positioning space for the aluminum-steel joint, helping to improve weld quality. High-frequency electromagnetic induction heating technology offers higher heating efficiency and precision than traditional welding methods. The induction heating coil quickly heats the surface of the steel claw to a preset temperature and, through the skin effect and proximity effect, generates localized heat accumulation during welding, ensuring uniform heat distribution. High-frequency induction brazing effectively controls the temperature distribution in the weld area, avoiding the formation of brittle Fe-Al intermetallic compounds at the aluminum-steel interface during fusion welding. This significantly improves the strength and toughness of the aluminum-steel joint and reduces the risk of cracking and brittleness. The aluminum-based brazing filler metal quickly melts during heating and fills the gaps in the joint area, enhancing the electrical conductivity and mechanical strength of the aluminum-steel joint. Compared to traditional low-temperature brazing, aluminum-based brazing filler metals provide better wettability and connection, reducing weak links in the joint. Compared with traditional welding equipment, the high-frequency induction heating method of this technology can complete the heating and connection process faster, thereby greatly improving production efficiency. The energy utilization efficiency of the high-frequency induction heating device is high, which can effectively save energy and equipment investment costs. By precisely controlling the heating process and welding parameters, the strength and stability of the aluminum-steel joint can be guaranteed. This enables the welding method to meet the high requirements for joint strength and conductive efficiency in the anode structure of the electrolytic cell, and improves the long-term service life and stability of the equipment. In summary, the high-frequency induction brazing device overcomes the difficulties in the connection of dissimilar metals of aluminum and steel by precisely controlling the welding process and optimizing the joint structure. It has significant advantages and can achieve efficient, stable and low-cost welding effects.

[0018] As a feasible implementation, the number of the screws is 4, and the length is 2 cm. The 4 screws are evenly fixed in a circular array on the end portion to be welded of the steel rod and are located in the hollow structure of the connector.

[0019] As a feasible implementation method, the aluminum rod has a diameter of 5 cm and a length of 5 cm, the steel rod has a diameter of 5 cm and a length of 5 cm, and the length of the connecting piece provided on one side of the steel rod is 2 cm.

[0020] As a feasible implementation method, the high-frequency electromagnetic induction heating coil is a hollow tube made of copper.

[0021] As a feasible implementation method, the diameter of the high-frequency electromagnetic induction heating coil is 8 cm.

[0022] As a feasible implementation method, the high-frequency electromagnetic induction heating coil has a shape consistent with the area to be welded of the aluminum rod and the steel rod after processing, and the high-frequency electromagnetic induction heating coil is 20 mm away from the outer circumferential surface of the steel rod.

[0023] As a feasible implementation manner, the high-frequency electromagnetic induction heating coil includes an arc-shaped induction coil and a square induction coil.

[0024] As a feasible implementation method, the induction power of the high-frequency electromagnetic induction heating coil is 0-40kW.

[0025] As a feasible implementation method, the induced current of the high-frequency electromagnetic induction heating coil is 70-90A.

[0026] As a feasible implementation, the induction heating time of the high-frequency electromagnetic induction heating coil is 90-300s.

[0027] As a feasible implementation manner, the distance between the surfaces to be welded of the aluminum rod and the steel rod is 80-120 mm.

[0028] In summary, this application has the following beneficial effects:

[0029] First, the aluminum-based brazing filler metal prepared by the present invention utilizes the metallic elements Al, Cu, Mg, and Si, as well as the rare elements Ce and La. Cu improves electrical conductivity and increases the strength of the welded joint, Mg reduces the brazing filler metal's oxidation tendency and improves its wettability, and Si and Al form a eutectic, significantly lowering the filler metal's melting point. Si also improves its ductility. The rare elements Ce and La purify the molten pool, refine the grain size, and improve wettability. The resulting brazing filler metal exhibits excellent wettability, inhibiting the excessive growth of intermetallic compounds (IMCs) at the metallurgical interface layer. This improves the mechanical properties of the dissimilar metal welded joint between the anode aluminum guide rod and the steel claw, enabling efficient and reliable dissimilar metal connections between the anode aluminum guide rod and the steel claw, and is therefore widely applicable in the brazing industry.

[0030] Second, the present invention provides a method for high-frequency induction brazing of dissimilar metals between anodized aluminum guide rods and steel claws. This method achieves steel-to-steel induction brazing and aluminum-to-steel induction fusion welding in separate steps. This method is simple, convenient, cost-effective, and easy to operate, overcoming the complex, costly, and difficult-to-control processes of aluminum-steel fusion welding and pressure welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The following is a brief introduction to the drawings used in describing the embodiments.

[0032] In the various drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the drawings are not drawn to scale, and certain features may be exaggerated or omitted to more clearly illustrate and explain the present application.

[0033] Figure 1 A schematic flow chart of a high-frequency induction brazing method for dissimilar metals of aluminum and steel in an electrolytic cell anode structure provided by an embodiment of the present application is shown;

[0034] Figure 2 A schematic flow chart of a high-frequency induction brazing method for dissimilar metals of aluminum and steel in an electrolytic cell anode structure provided by an embodiment of the present application is shown;

[0035] Figure 3 It shows a schematic diagram of the structure in which a screw is fixed to the end of a steel bar to be welded;

[0036] Figure 4 A structural schematic diagram of a high-frequency induction brazing device for dissimilar metals of aluminum and steel in an electrolytic cell anode structure provided in an embodiment of the present application is shown.

[0037] In the figure, 1. aluminum rod; 2. high-frequency electromagnetic induction heating coil; 3. connecting piece; 4. steel rod. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0039] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0041] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0042] In the description of this specification, the description with reference to the terms "some implementations", "some embodiments", "exemplary", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations 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. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are contradictory.

[0043] The "room temperature" mentioned in this specification has a meaning well known in the art, generally referring to 24-28°C.

[0044] High-Frequency Induction Fusion Brazing (HFIFB), a new composite heat source joining technology, uses a high-frequency alternating magnetic field to generate eddy current heating in a localized area of ​​the joint, achieving precise temperature control to achieve melting on the aluminum side and solidification on the steel side. This combines the high-strength bond of fusion welding with the low heat input advantages of brazing. Its core technology utilizes the "skin effect" and "proximity effect" of high-frequency induction heating to selectively heat the brazing filler metal. By adjusting welding parameters (frequency, power) and brazing filler metal composition, the thickness of the IMC layer can be effectively controlled and the interfacial stress distribution can be improved, while achieving efficient, low-deformation connections.

[0045] The present invention provides a method and device for high-frequency induction brazing of aluminum and steel dissimilar metals in an electrolytic cell anode structure. By utilizing the principle of high-frequency electromagnetic induction heating, it achieves an efficient connection between aluminum and steel, overcoming a series of problems in the traditional welding method in the connection of aluminum and steel dissimilar metals. The specific principle is as follows: by optimizing the composition and structural process of the aluminum-based brazing filler metal, a high-performance connection between aluminum and steel is achieved. The aluminum-based brazing filler metal is composed of Al, Cu, Mg, Si, La, and Ce in a specific proportion, wherein Cu and Si synergistically reduce the melting point of the brazing filler metal and improve wettability, and La and Ce refine the grains and enhance the joint strength. During welding, the brazing filler metal and the screw are arranged on the steel side surface, and the skin effect and proximity effect of high-frequency induction heating are utilized to accurately control the melting of the aluminum side and the solid-state bonding of the steel side, thereby suppressing the excessive growth of brittle Fe-Al intermetallic compounds (IMC). The mechanical anchoring effect of the screw achieves a multi-faceted stable connection. The method has the characteristics of low heat input, low deformation, and high joint strength. In addition to being suitable for high-frequency induction brazing of aluminum and steel dissimilar metals in electrolytic cell anode structures, it is also suitable for lightweight manufacturing of dissimilar metals in the fields of automobiles, aerospace, etc.

[0046] The preferred embodiments of the present invention are described in further detail below.

[0047] Figure 1 A schematic diagram of a high-frequency induction brazing method for dissimilar metals of aluminum and steel in an electrolytic cell anode structure provided by an embodiment of the present application is shown (see also the schematic diagram of the process Figure 2 ).like Figure 1 As shown, the method includes the following steps:

[0048] S101. A hollow annular connector is provided at the end of the steel rod to be welded, wherein the connector can accommodate the insertion of the end of the aluminum rod to be welded.

[0049] In this step, a hollow ring connector is placed at the end of the steel bar to be welded. This provides a secure insertion space for the aluminum bar to be welded. This connector helps maintain precise alignment between the aluminum and steel bars and ensures stability in the joint area.

[0050] Optionally, a Q235 steel rod with a diameter of 5 cm and a length of 5 cm and an aluminum rod with a diameter of 5 cm and a length of 5 cm are selected for welding.

[0051] S102. Deoxidize and sandblast the areas to be welded of the steel and aluminum bars and the connecting parts.

[0052] In this step, the areas to be joined, as well as the connecting parts, are deoxidized and sandblasted before welding to remove surface oxides and impurities. This process helps improve the weldability of the metal surfaces and reduces the effects of oxides and other interfering substances on the joint quality.

[0053] In some embodiments, deoxidation includes: using 400-grit coarse sandpaper to polish the areas to be welded of the steel rod and the aluminum rod to remove the surface oxide layer and scratches, polishing until the surface to be welded reveals a silvery-white metallic luster, and further smoothing and flattening the surfaces to be welded of the steel plate and the aluminum rod. For example, an ultrasonic cleaner is used to clean the surfaces to be welded of the steel plate and the aluminum rod to achieve smoothness and flattening, and then sandblasting is performed on the deoxidized steel side and aluminum side.

[0054] Optionally, the sandblasting specifically includes: at room temperature of 25° C., using at least one sand particle selected from silicon carbide, brown corundum, and garnet for sandblasting, with a spray gun pressure ≥ 0.3 MPa and a distance between the spray gun and the material surface ≤ 300 mm, thereby evenly removing the oxide layer on the surface of the steel rod and the aluminum rod in the area to be welded.

[0055] S103. After fixing a plurality of screws on the treated end of the steel rod to be welded, an aluminum-based brazing filler metal is placed inside the connector, wherein the aluminum-based brazing filler metal includes Al, Cu, Mg, Si, La, and Ce metal elements.

[0056] In this step, an aluminum-based brazing filler metal is placed in the joint area to be welded. The aluminum-based brazing filler metal has a low melting point and can effectively fill the aluminum-steel joint area. The selection and configuration of the aluminum-based brazing filler metal is the key in this technology, ensuring better welding effect and joint strength. In some embodiments, the weight percentages of each element in the Al-based brazing filler metal are Al 80-85%, Cu 5-10%, Mg 1-3%, Si 3-6%, La 1%, and Ce 1%. It should be noted that the raw materials of Cu, Mg, Si, and Al are metal particles with a purity of 99.9%. Among them, Cu and Si synergistically lower the melting point of the brazing filler metal and improve wettability, while La and Ce refine the grains and enhance the joint strength.

[0057] Alternatively, use four screws 2 cm long and arrange them in a circular pattern to fix the treated surface on the steel side. Figure 3 , Figure 3 It shows a schematic structural diagram of a screw fixed to the end of a steel rod to be welded.

[0058] S104: After inserting the end portion of the aluminum rod to be welded into the connector, a high-frequency electromagnetic induction heating coil is arranged around the area of ​​the steel rod and the aluminum rod to be welded.

[0059] In this step, for example, the processed Q235 steel rod and aluminum rod are placed in the high-frequency electromagnetic induction heating coil in the order of the aluminum rod on top and the Q235 steel rod on the bottom, so that the processed surface of the aluminum rod, the hollow structure (connector) of the Q235 steel rod, the screws and the aluminum-based solder are placed in the coil, and the position is adjusted to avoid contact with the high-frequency electromagnetic induction heating coil. For example, the distance between the high-frequency electromagnetic induction heating coil and the outer surface of the steel rod is set to 20mm to avoid mutual contact. After completing the above steps, check whether the various functions of the equipment are normal and set the welding parameters. Figure 4 , Figure 4 A structural schematic diagram of a high-frequency induction brazing device for dissimilar metals of aluminum and steel in an electrolytic cell anode structure provided in an embodiment of the present application is shown.

[0060] S105. Use the induced current generated by the high-frequency electromagnetic induction heating coil to heat the steel claw to a preset temperature, control the heating time to a preset time, and use the skin effect and proximity effect to achieve the melting of the aluminum side and the solid state bonding of the steel side to form a multi-faceted stable joint.

[0061] In this step, the current generated by the high-frequency electromagnetic induction heating coil is used to rapidly heat the surface of the steel rod to a preset temperature through the skin effect and the proximity effect, while the aluminum rod is kept at a relatively low temperature. This process controls the distribution of heat and avoids welding defects caused by uneven heat in traditional welding. Combination of melting and solid state: Under the action of high-frequency electromagnetic induction heating, the end of the aluminum rod to be welded will melt, while the steel claws remain in a solid state. By precisely controlling the heating time and temperature, a stable joint is formed between aluminum and steel in the microstructure. This combination method not only avoids the problem of brittle Fe-Al intermetallic compounds that are easily formed in traditional welding, but also effectively improves the structural strength and durability of the joint.

[0062] Optionally, the preset temperature is 700°C and the preset time is 300s. The high-frequency electromagnetic induction heating coil is a hollow copper tube with a diameter of 8 cm. Optionally, the high-frequency electromagnetic induction heating coil model is LH-40KW.

[0063] Figure 4 The schematic diagram of the structure of a high-frequency induction brazing device for dissimilar metals of aluminum and steel in an electrolytic cell anode structure provided by an embodiment of the present application is shown. Figure 4 The embodiment of the present application also provides a high-frequency induction brazing device for dissimilar metals of aluminum and steel in an electrolytic cell anode structure, which is applied to the above-mentioned brazing method. The high-frequency induction brazing device mainly comprises: a connector 3, which is arranged on the surface to be welded of a steel rod 4. The connector 3 is a hollow annular structure, and the connector 3 can accommodate the insertion of the end of the aluminum rod 1 to be welded; a screw ( Figure 4 Not shown, see Figure 3), multiple of which are evenly fixed in an annular array to the ends of the steel rod 4 to be welded and located within the hollow structure of the connector 3; a high-frequency electromagnetic induction heating coil 2 is arranged around the area where the steel rod 4 and the aluminum rod 1 are to be welded, and is used to heat the steel rod 4 and the aluminum rod 1, wherein an aluminum-based brazing filler metal layer (not shown in the figure) is provided between the ends of the steel rod 4 and the aluminum rod 1 to be welded, the interior of the connector 3, and the surrounding side of the aluminum rod 1. In one embodiment, the spacing between the surfaces of the aluminum rod and the steel rod to be welded is 80-120 mm to facilitate filling with the aluminum-based brazing filler metal.

[0064] Connector 3, a hollow ring-shaped structure, is positioned at the end of the steel bar 4 to be welded. Its primary function is to provide a precise insertion space for the end of the aluminum bar 1 to be welded. This hollow ring-shaped design stably secures the position of the aluminum bar 1 and the steel bar 4, ensuring their proper alignment during welding. The structural design of connector 3 enhances sealing and stability during welding.

[0065] Screw Fixing: Multiple screws are evenly spaced at the ends of the steel rods 4 to be welded, within the hollow structure of the connector 3. These screws ensure a tight connection between the connector 3 and the steel rod 4, preventing relative displacement during welding. They also help stabilize the joint area, preventing welding defects caused by temperature fluctuations or other external forces.

[0066] High-frequency electromagnetic induction heating coil 2: This coil is positioned around the welded area between the steel rod 4 and aluminum rod 1. Its primary function is to rapidly heat the welded area between the two rods by generating electromagnetic induction through the action of a high-frequency current. By precisely controlling the frequency and power of the induced current, the surface of the steel rod 4 is rapidly heated to a preset temperature, while the aluminum rod 1 remains at its desired melting point. This precise control of high-frequency induction heating avoids the problems of uneven heating and overheating associated with traditional heating methods.

[0067] Aluminum-based brazing filler metal layer: An aluminum-based brazing filler metal layer is placed between the steel rod 4 and the aluminum rod 1, within the connector 3, and around the aluminum rod 1. Aluminum-based brazing filler metal has a low melting point and melts rapidly during heating to fill the gaps between the aluminum and steel joints. The melting of the aluminum-based brazing filler metal creates a solid metallic connection between the aluminum and steel rods 4, enhancing the joint's strength and electrical conductivity.

[0068] Optionally, the aluminum rod 1 has a diameter of 5 cm and a length of 5 cm, the steel rod 4 has a diameter of 5 cm and a length of 5 cm, and the connector 3 provided on one side of the steel rod 4 has a length of 2 cm. Optionally, the connector 3 can be made of the same material as the steel rod and welded to the end of the steel rod 4 to be welded. Alternatively, the connector 3 can be constructed by machining a cylindrical groove in the end of the steel rod 4 to be welded, which is not strictly limited in this application.

[0069] In some embodiments, the high-frequency electromagnetic induction heating coil 2 is a hollow tube made of red copper with a diameter of 8 cm. Specifically, the shape of the high-frequency electromagnetic induction heating coil 2 after processing is consistent with the area to be welded of the steel rod 4 and the aluminum rod 1. In a specific embodiment, the high-frequency electromagnetic induction heating coil 2 is 20 mm away from the surface of the steel rod 4. Optionally, the high-frequency electromagnetic induction heating coil 2 includes an arc-shaped induction coil and a square induction coil. The induction power of the high-frequency electromagnetic induction heating coil 2 is 0-40kW, the induction current is 70-90A, and the induction heating time is 90-300s. Optionally, the model of the high-frequency electromagnetic induction heating coil is LH-40KW.

[0070] Melting and Bonding During Welding: High-frequency electromagnetic induction heating melts the end of the aluminum rod 1 to be welded, while the steel rod 4 remains solid. The melting of the aluminum-based brazing fills the gaps in the aluminum-steel joint. Precisely controlled heating time (300 seconds) and temperature (700°C) ultimately form a microstructurally stable joint between the aluminum rod 1 and the steel rod 4. This solid-state bonding, combined with the molten aluminum, ensures the joint's mechanical properties and durability.

[0071] In order to further illustrate the present application, the technical solutions provided in the present application are described in detail below in conjunction with the embodiments, but they should not be understood as limiting the scope of protection of the present application.

[0072] Example 1

[0073] A high-frequency induction brazing method for aluminum / steel dissimilar metals in an electrolytic cell anode structure, comprising the following steps:

[0074] (1) The six metals Cu, Mg, Si, Al, La, and Ce were weighed and mixed in the following proportions: 10 g, 3 g, 4 g, 32 g, 0.5 g, and 0.5 g.

[0075] (2) Pour metals Cu, Mg, Si, Al, La, and Ce into a crucible and heat them at 720° for 90 seconds to completely melt the metals, and continue stirring for 150 seconds.

[0076] (3) After heating, pour the metal in the crucible into the mold and cool it to room temperature to form it.

[0077] (4) An aluminum rod with a diameter of 5 cm and a length of 5 cm and a steel rod with a diameter of 5 cm and a length of 5 cm were selected. A hollow ring structure protruding 2 cm was provided on one side of the steel rod. The Q235 steel rod and the aluminum rod were polished with 400-grit coarse sandpaper to remove the surface oxide layer and scratches. After polishing until the cross section reveals a silvery-white metallic luster, the two cross sections were further smoothed and flattened. After the treatment was completed, the surface was sandblasted.

[0078] (5) After the pretreatment is completed, four 2 cm long screws are fixed in a circular pattern on the treated surface of the Q235 steel rod.

[0079] (6) The prepared block-shaped aluminum-based solder is evenly placed in the hollow structure of the Q235 steel rod.

[0080] (7) Place the processed Q235 steel rod and aluminum rod in the copper coil in the order of aluminum rod on top and Q235 steel rod on the bottom, so that the processed surface of the aluminum rod, the hollow structure of the Q235 steel rod, the screws and the aluminum-based solder are placed in the coil, and adjust the position to avoid contact with the copper coil.

[0081] (8) Check the functions of the high-frequency induction heating equipment and adjust the welding parameters. The specific welding parameters are: heating temperature is 700° and heating time is 300s.

[0082] (9) When the heating time reaches 300s, turn off the high-frequency induction heating equipment.

[0083] Example 2

[0084] A high-frequency induction brazing method for aluminum / steel dissimilar metals in an electrolytic cell anode structure, comprising the following steps:

[0085] (1) The six metals Cu, Mg, Si, Al, La, and Ce were weighed and mixed in the following proportions: 10 g, 4 g, 6 g, 29 g, 0.5 g, and 0.5 g.

[0086] (2) Pour metals Cu, Mg, Si, Al, La, and Ce into a crucible and heat them at 800°C for 100 seconds to completely melt the metals, and continue stirring for 130 seconds.

[0087] (3) After heating, pour the metal in the crucible into the mold and cool it to room temperature to form it.

[0088] (4) An aluminum rod with a diameter of 5 cm and a length of 5 cm and a steel rod with a diameter of 5 cm and a length of 5 cm were selected. A hollow ring structure protruding 2 cm was provided on one side of the steel rod. The Q235 steel rod and the aluminum rod were polished with 400-grit coarse sandpaper to remove the surface oxide layer and scratches. After polishing until the cross section reveals a silvery-white metallic luster, the two cross sections were further smoothed and flattened. After the treatment, the surface was sandblasted.

[0089] (5) After the pretreatment is completed, four 2 cm long screws are fixed in a circular shape on the treated surface of the Q235 steel rod.

[0090] (6) Place the prepared aluminum-based solder evenly in the hollow structure of the Q235 steel rod.

[0091] (7) Place the processed Q235 steel rod and aluminum rod in the copper coil in the order of aluminum rod on top and Q235 steel rod on the bottom, so that the processed surface of the aluminum rod, the hollow structure of the Q235 steel rod, the screws and the aluminum-based solder are placed in the coil, and adjust the position to avoid contact with the copper coil.

[0092] (8) Check the functions of the high-frequency induction heating equipment and adjust the welding parameters. The specific welding parameters are: heating temperature is 700° and heating time is 300s.

[0093] (9) When the heating time reaches 300s, turn off the high-frequency induction heating equipment.

[0094] The embodiments of the present application provide a high-frequency induction brazing method and device for aluminum-steel dissimilar metals in an electrolytic cell anode structure. By arranging a hollow tube structure and a steel-side fixing screw at one end of a Q235 steel rod, the aluminum rod, Q235 steel rod, aluminum-based brazing filler metal and screw are placed in a coil, and an eddy current thermal effect is generated in a local area by a high-frequency alternating magnetic field. Local heating is performed by utilizing the "skin effect" and "proximity effect" of high-frequency induction heating, thereby achieving multi-faceted and stable connection between the aluminum-based brazing filler metal and the aluminum rod, the aluminum-based brazing filler metal and Q235 steel, the aluminum-based brazing filler metal and the inner wall of the hollow tube structure, and the aluminum-based brazing filler metal and the screw; combined with the low heat input advantage of brazing, the aluminum-based brazing filler metal and the screw jointly form a mechanical-metallurgical composite connection interface, thereby achieving an efficient and low-deformation connection, and obtaining a welded joint with no obvious defects and excellent mechanical properties. At the same time, the addition of Mg to the brazing filler metal can lower its melting point, Cu significantly improves its wettability and fluidity, making it easier to spread on the surface of the base material, and Si significantly lowers its melting point, enabling brazing at lower temperatures. The addition of La effectively increases the tensile strength and spreading area of ​​the filler metal, and Ce significantly improves its spreading properties, increasing the shear strength of the brazed joint. In summary, the addition of Mg, Cu, Si, La, and Ce can optimize the performance of aluminum-based brazing filler metals in terms of melting point, wettability, fluidity, and mechanical properties, thereby improving the quality and reliability of brazed joints.

[0095] Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present application. Those skilled in the art should understand that, although the present application has been described in detail with reference to the aforementioned embodiments, the technical solutions described in the aforementioned embodiments may be modified or some of the technical features thereof may be replaced with equivalents. However, such modifications or replacements do not deviate from the spirit and scope of the technical solutions in the various embodiments of the present application.

Claims

1. A high-frequency induction brazing method for dissimilar metals of aluminum and steel in an electrolytic cell anode structure, characterized in that: include: A hollow annular connector is provided at the end of the steel rod to be welded, and the connector can accommodate the insertion of the end of the aluminum rod to be welded; Deoxidation and sandblasting of the areas to be welded and the connecting parts of steel and aluminum bars; After fixing a plurality of screws at the end of the treated steel rod to be welded, an aluminum-based brazing filler metal is placed inside the connector, wherein the aluminum-based brazing filler metal includes Al, Cu, Mg, Si, La, and Ce metal elements; After the end of the aluminum rod to be welded is inserted into the connector, a high-frequency electromagnetic induction heating coil is arranged around the steel rod and the area of ​​the aluminum rod to be welded; The steel claw is heated to a preset temperature by the induced current generated by the high-frequency electromagnetic induction heating coil, and the heating time is controlled to the preset time. The skin effect and proximity effect are used to achieve the melting of the aluminum side and the solid-state bonding of the steel side to form a multi-faceted stable joint.

2. The method according to claim 1, characterized in that The method further comprises: the aluminum-based brazing filler metal comprises, by weight percentage, 80-85% Al, 5-10% Cu, 1-3% Mg, 3-6% Si, 1% La, and 1% Ce.

3. The method according to claim 1, characterized in that The deoxidation comprises: Use 400-grit coarse sandpaper to polish the areas to be welded of the steel rod and the aluminum rod to remove the surface oxide layer and scratches. After polishing until the surface to be welded reveals a silvery-white metallic luster, the surfaces to be welded of the steel plate and the aluminum rod are further smoothed and flattened.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: According to weight percentage, 80-85% of Al, 5-10% of Cu, 1-3% of Mg, 3-6% of Si, 1% of La and 1% of Ce are weighed, stirred evenly and then smelted. The molten metal liquid is cooled and shaped to obtain an aluminum-based brazing filler metal for welding.

5. The method according to claim 4, characterized in that The stirring time of the aluminum-based solder is not less than 120 seconds; the melting temperature is 700-800° C., the melting time is 60-120 seconds, and the cooling method is room temperature molding.

6. The method according to any one of claims 1 to 3, characterized in that There are four screws, each 2 cm long, and the four screws are evenly fixed in a circular array on the end portion of the steel rod to be welded and are located in the hollow structure of the connector.

7. The method according to any one of claims 1 to 3, characterized in that The aluminum rod has a diameter of 5 cm and a length of 5 cm, the steel rod has a diameter of 5 cm and a length of 5 cm, and the length of the connecting piece provided on one side of the steel rod is 2 cm.

8. The method according to any one of claims 1 to 3, characterized in that The preset temperature is 700° C., and the preset time is 300 seconds.

9. The method according to any one of claims 1 to 3, characterized in that The high-frequency electromagnetic induction heating coil is a hollow copper tube with a diameter of 8 cm.

10. A high-frequency induction brazing device for dissimilar metals of aluminum and steel in an electrolytic cell anode structure, characterized in that: include: A connecting piece is provided on the surface of the steel rod to be welded, the connecting piece is a hollow ring structure, and the connecting piece can accommodate the insertion of the end of the aluminum rod to be welded; The screws are provided in a plurality and are evenly fixed to the ends of the steel bars to be welded in an annular array and are located in the hollow structure of the connector; A high-frequency electromagnetic induction heating coil is arranged around the area to be welded of the steel rod and the aluminum rod, and is used to heat the steel rod and the aluminum rod, wherein an aluminum-based brazing material layer is provided between the ends to be welded of the steel rod and the aluminum rod, the interior of the connector and the surrounding side of the aluminum rod.

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