Low-abrasion high-strength high-conductivity copper alloy, corresponding contact wire and preparation method

Abstract

According to the low-abrasion high-strength high-conductivity copper alloy, the mechanical abrasion resistance, the electrical abrasion resistance and the chemical corrosion resistance of a contact wire manufactured through the low-abrasion high-strength high-conductivity copper alloy are improved at the same time in the using process, and therefore the low-abrasion copper alloy contact wire is obtained. The invention discloses a high-strength copper alloy which is characterized by comprising the following components in percentage by mass: 0.2-1.0 wt% of Cr, 0.02-0.2 wt% of Zr, 0.01-0.1 wt% of Sn and the balance of Cu and inevitable impurities, and the sum of the mass percentages of all the components is 100%.

Description

Technical Field

[0001] The present invention relates to the technical field of copper alloy materials, and specifically to a low-wear, high-strength, high-conductivity copper alloy. The present invention also provides a low-wear, high-strength, high-conductivity copper alloy contact wire. The present invention also provides a method for preparing the low-wear, high-strength, high-conductivity copper alloy contact wire. Background Art

[0002] The subway locomotive obtains electricity through the sliding contact between the carbon slide plate on the pantograph and the contact wire, so that the subway locomotive can operate and work normally. In recent years, with the vigorous development of urban rail transit, abnormal wear of subway contact wires is common. At present, experts, scholars, design units, construction units and operating units mainly study, analyze and solve the problem of severe friction and wear of the pantograph and the catenary from the aspects of the current-carrying friction and wear mechanism of the pantograph and the construction of the catenary and the influence of the carbon slide plate on the current-carrying friction pair. However, the problem of severe wear of the contact wire still exists.

[0003] Domestic subways generally use CTA contact wires, which have excellent electrical conductivity, but have poor wear resistance under the combined effects of complex and harsh working environments such as mechanical wear, electrical wear, and chemical corrosion. Some domestic subways use copper-chromium-zirconium alloy contact wires to solve the problem of abnormal wear of contact wires, but under the action of high-temperature arcs, the wear resistance of copper-chromium-zirconium alloy contact wires has no obvious advantages.

[0004] This patent develops a low-wear, high-strength and high-conductivity copper alloy based on the material and processing method of the contact wire itself. Summary of the invention

[0005] The object of the present invention is to overcome the above-mentioned shortcomings and provide a low-wear, high-strength and high-conductivity copper alloy, so that the contact wire made thereof has improved mechanical wear resistance, electrical wear resistance and chemical corrosion resistance during use, thereby obtaining a low-wear copper alloy contact wire.

[0006] A low-wear, high-strength and high-conductivity copper alloy, characterized in that its components, in terms of mass percentage, are as follows: 0.2-1.0wt% Cr, 0.02-0.2wt% Zr, 0.01-0.1wt% Sn, and the remainder is Cu and unavoidable impurities, and the total mass percentage of each component is 100%.

[0007] A low-wear, high-strength, high-conductivity copper alloy contact wire, characterized in that it is made of a low-wear, high-strength, high-conductivity copper alloy material to form a rod blank, which is then processed to obtain a contact wire with a corresponding cross-sectional shape.

[0008] A method for preparing a low-wear, high-strength, high-conductivity copper alloy contact wire, characterized in that:

[0009] The copper liquid is obtained by smelting according to the composition percentage of the low-wear, high-strength and high-conductivity copper alloy, and then cast into a rod billet, and then successively undergoes continuous extrusion, deformation treatment, aging treatment, forming, and deep cryogenic treatment processes to prepare a low-wear, high-strength and high-conductivity copper alloy contact wire with a set cross-sectional shape.

[0010] It is further characterized by:

[0011] It includes the following specific steps:

[0012] S1. Melting and casting: using an electromagnetic induction furnace for melting and casting to obtain copper alloy cast rods, wherein the electromagnetic induction furnace includes: a melting zone, a transition zone, and an upper continuous casting zone, and the electromagnetic induction technology makes the copper solution composition evenly distributed;

[0013] S2, continuous extrusion, using a continuous extruder to make the copper-chromium-zirconium alloy cast rod into a copper alloy extruded rod with a diameter of 20-32 mm;

[0014] S3, cold deformation, subjecting a copper alloy extruded rod with a diameter of 20-32 mm to a cold deformation treatment of 0-65%;

[0015] S4, aging treatment, bright aging treatment is performed on the cold-deformed copper alloy rod blank;

[0016] S5, drawing and forming, drawing the copper alloy rod blank after aging treatment into a contact line of required size;

[0017] S6. Cryogenic treatment: the copper alloy contact wire is put into a continuous cryogenic treatment device for online cryogenic treatment.

[0018] It is further characterized by:

[0019] Step S1: smelting and casting comprises the following steps:

[0020] S101 oven, add baked charcoal into the electromagnetic induction furnace, and bake the smelting furnace to achieve a good furnace opening state;

[0021] S102 smelting, high purity cathode copper plate is added to the smelting area, the smelting furnace is heated to 1070±15℃, the copper plate is melted into copper liquid, and the copper liquid flows from the smelting area to the transition area and flows to the upper continuous casting area. During this process, the copper liquid is always covered with 150-200mm of graphite powder and calcined charcoal until the copper liquid reaches the usage amount;

[0022] S103 adding solvent, adding 0.05-0.1wt% sodium chloride to the copper liquid to prevent the melt from inhaling air, and then adding a solvent that has been deoxidized and dehydrated to the inner surface of the copper liquid, the solvent is composed of high-purity dehydrated borax, glass chips, soda ash and fluorite, and the ratio is 3:4:1:1. After the solvent is melted and stabilized, it forms a covering layer, which fully covers the upper part of the copper liquid and the lower part of the graphite powder and calcined charcoal, and can effectively prevent the oxidation and inhalation of the copper liquid. At the same time, the copper liquid, charcoal and graphite powder are separated, which is not only convenient for slag removal, but also can well prevent the oxidation and inhalation of the copper liquid during slag removal;

[0023] S104: Install a crystallizer in the upward continuous casting area, remove the calcined charcoal and slag on the upper layer of the solvent in the upward continuous casting area, remove the solvent, and install one or more upward continuous casting crystallizers according to production needs;

[0024] S105 adds Sn element, and uses anti-oxidation filler in the smelting area to add high-purity tin according to the alloy ratio. The addition of tin element not only reduces the solubility of hydrogen in copper liquid, but also improves the strength, wear resistance and arc resistance of copper-chromium-zirconium alloy rod blank;

[0025] S106 purifies the solution, using an anti-oxygen filler in the smelting area to add dry Cu-18Mg and Cu-50Ca master alloys in accordance with the ratio requirements to remove oxygen from the copper liquid and other impurities in the smelting furnace;

[0026] S107 dehydrogenation, in the smelting zone, 0.01-1wt% CuO powder is added into the furnace using an anti-oxidation filler to remove hydrogen from the copper liquid;

[0027] S108 sampling and testing, sampling at multiple points in the upper continuous casting area to test the oxygen, hydrogen and impurity content of the copper alloy casting rod, if the standard is met, proceed to step S109, if not, proceed to step S106 or S107 appropriately according to the test results until the test results meet the standard;

[0028] S109 adds Cr and Zr alloys, raises the temperature of the copper liquid to 1250°C-1300°C, first adds CuCr to the bottom of the copper liquid using an anti-oxygen filler according to the ratio, and after it is evenly distributed, adds CuZr to the bottom of the copper liquid using an anti-oxygen filler according to the ratio to make it evenly distributed;

[0029] S110 secondary sampling and testing, sampling and testing the copper-chromium-zirconium alloy casting rods at multiple points in the upper continuous casting area, and after the composition meets the standard, multiple upper crystallizers start continuous upper casting. If the standard is not met, step S106 S107 or S109 is appropriately performed according to the test results until the test results meet the standard;

[0030] S111 upward continuous casting, the crystallizer starts to cast continuously upward, and the casting rod is cooled by rapid cooling, so as to obtain a copper-chromium-zirconium alloy casting rod with uniform composition and structure and fine grains;

[0031] S112 slag removal. During the smelting and upward continuous casting process, regular and rapid slag removal operations should be carried out according to actual conditions. In the process of slag removal, in order to ensure the composition of the copper-chromium-zirconium alloy solution, the addition amount of Cu-18Mg, Cu-50Ca intermediate alloy and CuO powder should be appropriately increased to reduce the content of hydrogen and oxygen in the copper liquid.

[0032] Step S6 cryogenic treatment is to place the copper alloy contact wire in a continuous cryogenic treatment device for cryogenic treatment, the cryogenic treatment is performed at least once, the continuous cryogenic treatment device includes at least one group of temperature adjustment bins, at least one cryogenic treatment bin, at least one circulating spray box, at least one drying device; a wire take-up machine is arranged at the rear of the continuous cryogenic treatment device, and each group of temperature adjustment bins includes at least two temperature adjustment bins;

[0033] The continuous cryogenic treatment device in step S6 is provided with several groups of temperature regulating bin groups and several groups of cryogenic treatment bins according to the performance requirements of the contact line. The contact line moves along the temperature regulating bin group for staged cooling, enters the cryogenic treatment bin for cryogenic operation, and then passes through a circulating spray box and a drying device for cooling and drying. According to the performance of the contact line, three options are made: option one, step cooling and deep cooling again, then entering the cryogenic treatment bin for deep cooling, then passing through a circulating spray box and a drying device for cooling and drying; option two, directly entering the cryogenic treatment bin again, then passing through a circulating spray box and a drying device for cooling and drying; option three, being wound up by a wire take-up machine; the number of deep cooling times of the contact line is preset, and then the number of temperature regulating bin groups and the number of cryogenic treatment bins are preset, the continuous cryogenic device is pre-assembled, and the contact line is guided to pass through the corresponding temperature regulating bin group, cryogenic treatment bin, circulating spray box, and drying device after drawing and forming, until it is finally wound up by a wire take-up machine;

[0034] Each temperature-adjusting chamber is provided with a spiral coil, which is arranged along the straight-line advancing direction of the wire body. The wire body passes through the central cavity of the spiral coil. A horizontally arranged guide hub is provided in the cryogenic treatment chamber. The wire body passes through the center of the spiral coil of each temperature-adjusting chamber in sequence and then enters the cryogenic treatment chamber. The wire body is spirally wrapped around the outer circumference of the guide hub in a single layer and then output in a straight line state.

[0035] In step S6, the single cryogenic treatment temperature of the contact wire is -100°C to -190°C, and the time is 5 to 30 minutes. The single cryogenic time is controlled by adjusting the wire taking-up speed of the wire take-up machine, the number of turns of the wire wound around the guide hub in the cryogenic treatment chamber, and the outer diameter of the guide hub;

[0036] The wire body passes through the circulating spray box, drying device and finally is reeled by the wire take-up machine in a straight state;

[0037] Both the temperature control chamber and the cryogenic treatment chamber use a cryogenic medium that does not react with the contact wire for online cryogenic treatment; the copper alloy contact wire after cryogenic treatment not only has improved strength, wear resistance, corrosion resistance and dimensional stability, but also has high electrical conductivity.

[0038] It is further characterized by:

[0039] The standards for oxygen, hydrogen and impurity contents in step S108 are: oxygen mass percentage ≤ 0.0005%, hydrogen mass percentage ≤ 0.0005%, and impurity content ≤ 0.05%;

[0040] The detection in steps S108 and S110 needs to be completed within 5-10 minutes.

[0041] After adopting the above technical scheme, by changing the silver alloy content, adding 0.2-1.0wt% Cr, 0.02-0.2wt% Zr, and 0.01-0.1wt% Sn to adjust the material properties, optimize the process nodes of smelting and casting, and optimize the process flow of deep cryogenic treatment, the processed copper alloy contact wire not only has improved strength, wear resistance, corrosion resistance and dimensional stability, but also has high electrical conductivity; through microalloying, continuous extrusion, cold deformation, aging treatment and deep cryogenic treatment, the copper alloy contact wire has high strength, wear resistance, corrosion resistance, electrical conductivity and excellent stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The structure schematic diagram of the continuous cryogenic treatment device used in the present invention;

[0043] Figure 2 A three-dimensional schematic diagram of a spiral coil of a continuous cryogenic treatment device used in the present invention;

[0044] Figure 3 A cross-sectional view of a contact line corresponding to an embodiment of the present invention;

[0045] The names corresponding to the serial numbers in the figure are as follows:

[0046] Cryogenic medium storage tank 1, transformer 2, safety valve 3, non-return valve 4, cryogenic treatment chamber 5, evaporator 6, temperature control and display device 7, temperature detection device 8, temperature adjustment chamber 9, circulation spray box 10, guide wheel hub 11, drying device 12, wire take-up machine 13, sprayer 14, return water pipeline 15, spray box temperature controller 16, pump 17, heating and heat preservation device 18, spray liquid storage tank 19, condensate recovery pipeline 20, spiral coil 21, collection tank 22, pressure gauge 23, condensation filter 24, compressor 25. DETAILED DESCRIPTION

[0047] A low-wear, high-strength and high-conductivity copper alloy has the following components in percentage by mass: 0.2-1.0wt% Cr, 0.02-0.2wt% Zr, 0.01-0.1wt% Sn, the remainder being Cu and unavoidable impurities, and the total percentage by mass of each component is 100%.

[0048] A low-wear, high-strength and high-conductivity copper alloy contact wire is made from a low-wear, high-strength and high-conductivity copper alloy material to form a rod blank, which is then processed to obtain a contact wire with a corresponding cross-sectional shape.

[0049] A method for preparing a low-wear, high-strength, high-conductivity copper alloy contact wire: smelting the low-wear, high-strength, high-conductivity copper alloy according to the composition percentage to obtain molten copper, then casting it into a rod blank, and then sequentially undergoing continuous extrusion, deformation treatment, aging treatment, forming, and deep cryogenic treatment processes to prepare the low-wear, high-strength, high-conductivity copper alloy contact wire with a set cross-sectional shape.

[0050] Specific embodiment 1 of the low-wear, high-strength and high-conductivity copper alloy contact wire, wherein the components in mass percentage are as follows: 0.6wt% Cr, 0.11wt% Zr, 0.05wt% Sn, and the remainder is Cu and unavoidable impurities, and the total mass percentage of each component is 100%. The preparation method thereof comprises the following specific steps:

[0051] S1. Melting and casting: using an electromagnetic induction furnace for melting and casting to obtain copper alloy cast rods, wherein the electromagnetic induction furnace includes: a melting zone, a transition zone, and an upper continuous casting zone, and the electromagnetic induction technology makes the copper solution composition evenly distributed;

[0052] S101 baking furnace, add baked charcoal to the melting area, transition area and upper casting area of ​​the electromagnetic induction furnace, and bake the melting furnace to achieve a good furnace opening state;

[0053] S102 smelting, high purity cathode copper plate is added to the smelting area, the smelting furnace is heated to 1070±15℃, the copper plate is melted into copper liquid, and the copper liquid flows from the smelting area to the transition area and flows to the upper continuous casting area. During this process, the copper liquid is always covered with 150-200mm of graphite powder and calcined charcoal until the copper liquid reaches the usage amount;

[0054] S103 adds solvent, adds 0.05-0.1wt% sodium chloride to the copper liquid to prevent the melt from inhaling air, and after 5-10 minutes, adds a mixture of high-purity dehydrated borax, glass scraps, soda ash and fluorite that have been deoxidized and dehydrated to the inner surface of the copper liquid in a ratio of 3:4:1:1, so that after melting, a 10mm covering layer is formed to fully cover the upper part of the copper liquid and the lower part of the graphite powder and calcined charcoal, which can effectively prevent the oxidation and inhalation of the copper liquid, and at the same time separate the copper liquid from the charcoal and graphite powder, which is not only convenient for slag removal, but also can well prevent the oxidation and inhalation of the copper liquid during slag removal;

[0055] S104 Install a crystallizer in the upward continuous casting area, remove the calcined charcoal and slag on the upper layer of the solvent in the upward continuous casting area, push away the solvent, and install an upward continuous casting crystallizer according to production needs;

[0056] S105 adds Sn element, and uses anti-oxidation filler in the smelting area to add high-purity tin according to the alloy ratio. The addition of tin element not only reduces the solubility of hydrogen in copper liquid, but also improves the strength, wear resistance and arc resistance of copper-chromium-zirconium alloy rod blank;

[0057] S106 purifies the solution, using an anti-oxygen filler in the smelting area to add dry Cu-18Mg and Cu-50Ca master alloys in accordance with the ratio requirements to remove oxygen from the copper liquid and other impurities in the smelting furnace;

[0058] S107 dehydrogenation, in the smelting zone, 0.01-1wt% CuO powder is added into the furnace using an anti-oxidation filler to remove hydrogen from the copper liquid;

[0059] S108 sampling and testing, sampling at multiple points in the upper continuous casting area to test the oxygen, hydrogen and impurity content of the copper alloy casting rod, if the standard is met (oxygen mass percentage ≤ 0.0005%, hydrogen mass percentage ≤ 0.0005%, impurity content ≤ 0.05%), proceed to step S109, if not up to standard, proceed to step S106 or S107 according to the test results, until the test results meet the standard;

[0060] S109 adds Cr and Zr alloys, raises the temperature of the copper liquid to 1250°C-1300°C, first adds CuCr to the bottom of the copper liquid using an anti-oxygen filler according to the ratio, and after it is evenly distributed, adds CuZr to the bottom of the copper liquid using an anti-oxygen filler according to the ratio to make it evenly distributed;

[0061] S110 secondary sampling and testing, sampling and testing the copper-chromium-zirconium alloy casting rods at multiple points in the upper continuous casting area, and after the composition meets the standard, multiple upper crystallizers start continuous upper casting. If the standard is not met, step S106 S107 or S109 is appropriately performed according to the test results until the test results meet the standard;

[0062] S111 upward continuous casting, the crystallizer starts to cast continuously upward, and the casting rod is cooled by rapid cooling, so as to obtain a copper-chromium-zirconium alloy casting rod with uniform composition and structure and fine grains;

[0063] S112 Slag removal: During the smelting and upward continuous casting process, regular and rapid slag removal should be carried out according to the actual situation. In the process of slag removal, in order to ensure the composition of the copper-chromium-zirconium alloy solution, the addition amount of Cu-18Mg, Cu-50Ca master alloy and CuO powder should be appropriately increased to reduce the content of hydrogen and oxygen in the copper liquid;

[0064] S2, continuous extrusion, using a continuous extruder to make a copper alloy extruded rod with a diameter of 32 mm from the copper-chromium-zirconium alloy cast rod;

[0065] S3, cold deformation, subjecting a copper alloy extruded rod with a diameter of 32 mm to a cold deformation treatment of 0-65%;

[0066] S4, aging treatment, bright aging treatment is performed on the cold-deformed copper alloy rod blank;

[0067] S5, drawing and forming, drawing the copper alloy rod blank after aging treatment into a contact line of required size;

[0068] S6. Cryogenic treatment: The copper alloy contact wire is subjected to online cryogenic treatment in a continuous cryogenic treatment device. The continuous cryogenic treatment device (see Figure 1 and Figure 2 ) includes a temperature adjustment bin group, a cryogenic treatment bin 5, a circulating spray box 10, and a drying device. The temperature adjustment bin group includes four temperature adjustment bins, and a wire take-up machine is arranged behind the continuous cryogenic treatment device;

[0069] One end of the contact wire is connected to a chain, which passes through four temperature-adjusting chambers 9, is wound several times on a guide hub 11 in a cryogenic treatment chamber 5, and is then connected to a wire take-up machine 13 through a circulating spray box 10 and a drying device 12.

[0070] Turn on the spray box temperature controller 16 to start the heating and heat preservation device 18 to work. When the set temperature reaches 20°C±1°C and the temperature stabilizes, turn on the pump 17 and the spray liquid is sprayed through the sprayer 14.

[0071] Turn on the temperature control and display device 7 and the temperature detection device 8 on each temperature adjustment chamber 9 and the cryogenic treatment chamber 5, and set the temperature of each temperature control and display device 7 to -10°C, -40°C, -70°C, -90°C, and -100°C from left to right, with a temperature error of ±2°C. The temperature control and display device 7 is integrated with a flow regulating valve, which performs adaptive flow regulation according to the set temperature value.

[0072] The continuous cryogenic treatment device includes a circulating refrigeration system. The circulating refrigeration system in the specific embodiment includes a cryogenic medium storage tank 1, a transformer 2, two safety valves 3, two one-way valves 4, an evaporator 6, a condensation filter 24, a compressor 25, a cryogenic medium collection tank 22 and a plurality of pipelines, wherein the cryogenic medium collection tank 22 is the same as the cryogenic medium storage tank 1 and can be recycled, wherein the evaporator 6 and the compressor 25 are both provided with a pressure gauge 23.

[0073] Turn on the switch of the cryogenic medium storage tank 1, set the transformer 2, open the safety valve 3 and the evaporator 6, and the cryogenic medium enters the evaporator 6 from the cryogenic medium storage tank 1 through the transformer 2, the safety valve 3, the one-way valve 4, and the cryogenic medium. After the cryogenic medium is vaporized, it flows into the upper end of the spiral coil 21 through the pipeline through the temperature control and display device 7, and the temperature of the temperature control chamber and the cryogenic treatment chamber is cooled accordingly. The temperature detection device 8 constantly detects the temperature of each temperature control chamber and the cryogenic treatment chamber. When the set temperature is reached, the temperature control and display device 7 controls the cryogenic medium to stop inputting; when the temperature detected by the temperature detection device 8 is higher than the set temperature, the temperature control and display device 7 controls the vaporized cryogenic medium to pass in, and the above process is repeated to keep each temperature control chamber and the cryogenic treatment chamber 5 at the set temperature.

[0074] The safety valve, condensation filter 24, compressor 25 and collection tank 22 on the cryogenic medium recovery pipeline are opened to recover the cryogenic medium.

[0075] The wire take-up machine 13 is turned on, and the rotation of the wire drum drives the chain to rotate, so that the contact wire passes through multiple temperature regulating boxes 9 in sequence and reaches the cryogenic treatment chamber 5, in which it is cryogenically treated. The cryogenic treatment time is adjusted by the wire drum take-up speed and the number of contact wire winding turns on the hub. The deep cooling time of each part of the contact wire is 30 minutes. After that, it enters the spray box 10, and the spray liquid fully contacts the contact wire, so that the contact wire is quickly heated to room temperature. After being dried by the drying device 12, it is wound on the wire drum of the wire take-up machine 13.

[0076] During the cryogenic treatment process, the circulating refrigeration system and the circulating spraying system continue to work, and the cryogenic medium flows out from the lower end of each spiral coil and the cryogenic treatment chamber, and is collected in the condensation filter 24 for filtration, and then compressed into liquid by the compressor 25, and collected in the collection tank 22 for secondary recycling. The spray liquid is sprayed from the multiple sprayers 14 inside the spray box 10, and after contacting the contact line, it enters the spray liquid storage tank 19 through the funnel area and the return pipe 15 below the spray box 10, and at the same time, the condensed water recovery pipe 20 flows into the spray liquid storage tank 19, and is recycled in this way.

[0077] After the wire collection is completed, turn off the wire collection device, drying device, related switches of the circulating refrigeration system, and the circulating spray system switch.

[0078] In Comparative Example 1, the step S105 of adding the Sn element in Example 1 is not performed, and the remaining steps are the same as those in Example 1.

[0079] In Comparative Example 2, step S6 in Example 1 is not performed, and the remaining steps are the same as those in Example 1.

[0080] In Comparative Example 3, the step S105 of adding the Sn element and the step S6 in Example 1 are not performed, and the remaining steps are the same as those in Example 1.

[0081] In Comparative Example 4, the internal set temperature of the cryogenic treatment chamber of the continuous cryogenic treatment device in step S6 of Example 1 is adjusted to -190±2°C, the cryogenic time of each contact line is 30 minutes, and the remaining steps are the same as Example 1.

[0082] The copper-chromium-zirconium alloy contact wire (CTCZ150) prepared in Example 1 and Comparative Examples 1-4 was tested for performance. The cross-sectional dimensions of the contact wires were the same. Figure 3 The main electromechanical performance test results are as follows:

[0083]

[0084] It can be seen from the table that the tensile strength, wear resistance and arc erosion resistance of the copper-chromium-zirconium alloy contact wires prepared by Example 1 and Comparative Example 4 are relatively high, but the repeated bending performance of Comparative Example 4 is poor and the surface quality is unqualified.

[0085] The wear resistance and arc erosion resistance of Comparative Example 1 are slightly lower than those of Example 1 due to the lack of Sn element addition, and the conductive performance is slightly improved.

[0086] The copper-chromium-zirconium alloy contact wires prepared by Comparative Examples 2 and 3 have lower tensile strength and softening rate, and their wear performance and arc erosion resistance are worse than those of Example 1.

[0087] After the copper-chromium-zirconium alloy contact wire is formed, the online cryogenic treatment can not only increase the dislocations in the copper-chromium-zirconium alloy contact wire to form dislocation rings, increase the number of twins, change the morphology, increase the precipitated phases, and reduce the size and distribute them evenly; it can also eliminate defects such as pores and holes inside the contact wire, and improve the density of the copper-chromium-zirconium alloy contact wire; in addition, it improves the stability of the organization, performance, and size of the copper-chromium-zirconium alloy contact wire during use, especially in extreme environments. In summary, cryogenic treatment changes the microstructure of the copper-chromium-zirconium alloy contact wire, eliminates defects, and comprehensively improves its strength, hardness, wear resistance, corrosion resistance, arc ablation resistance, and stability. It also has high electrical conductivity, which enables it to have a long service life in extreme environments.

[0088] In the present invention, a continuous cryogenic device is used to continuously cryogenically treat the wire rod, and the continuous cryogenic device has the following advantages:

[0089] The present invention is provided with a plurality of independent temperature adjustment chambers and cryogenic treatment chambers, each of which is provided with an independent temperature control system. By controlling the temperature of each temperature adjustment chamber respectively, the purpose of gradually changing the contact line from room temperature to a low temperature, ultra-low temperature, or cryogenic treatment temperature environment is achieved, and the online temperature change treatment of the contact line is realized, which effectively avoids defects such as brittle cracking of the contact line caused by a sudden drop in temperature;

[0090] The present invention can make the following adjustments according to the performance requirements of the product: (1) by increasing or decreasing the number of temperature-adjusting bins and cryogenic treatment bins, the purpose of slow cooling and repeated cryogenic treatment can be achieved; (2) by setting the temperature of each temperature-adjusting bin in the temperature-changing device to achieve multi-mode temperature-changing treatment; (3) the cryogenic treatment time can be adjusted by the wire-taking speed, the size of the temperature-adjusting bin, the winding condition of the contact wire in the cryogenic treatment bin, etc. The present invention has extremely high flexibility and adaptability, and can meet the cryogenic treatment requirements of various long-length wire products;

[0091] A guide wheel hub is arranged in the cryogenic treatment chamber, so that the contact wire is wound on it for cryogenic treatment, which not only greatly expands the cryogenic treatment time range, makes the applicability of the continuous cryogenic device wider, but also saves the equipment space;

[0092] By introducing cooling medium into the spiral coil, the contact line at its core is subjected to indirect cryogenic treatment, which has the following advantages: (1) the direct thermal shock of the cryogenic medium on the contact line can be effectively reduced, which not only further avoids the occurrence of defects such as cracks, but also reduces the erosion of the surface of the contact line by the cryogenic medium and its impurities, thereby ensuring the surface quality of the product; (2) the spiral coil can quickly reach the set temperature, and the temperature distribution is uniform, which is conducive to rapid and high-quality cryogenic treatment; (3) the efficient recovery and reuse of the cryogenic medium is achieved;

[0093] The lower part of each temperature-adjusting chamber and cryogenic treatment chamber is funnel-shaped, and the condensate recovery pipes are tightly connected, with the overall downward angle, which is convenient for condensate recovery and can effectively prevent gas circulation between temperature-adjusting chambers;

[0094] During operation, the continuous cryogenic device has a complete collection and circulation system, which can effectively recycle and reuse cryogenic media, spray liquids and other liquids, effectively reducing the production cost of the product and avoiding the leakage of harmful substances, achieving the goals of energy saving and environmental protection.

[0095] The copper-chromium-zirconium alloy contact wire obtained by the invention has a tensile strength of 400MPa-650MPa, a conductivity of 75%IACS-94%IACS, and a wear performance superior to that of a copper-silver alloy contact wire and a copper-chromium-zirconium alloy contact wire with the same strength.

[0096] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0097] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A low-wear, high-strength, high-conductivity copper alloy, characterized in that: The composition contents thereof in terms of mass percentage are as follows: 0.2-1.0wt% of Cr, 0.02-0.2wt% of Zr, 0.01-0.1wt% of Sn, and the remainder being Cu and unavoidable impurities, and the total mass percentage of each component is 100%.

2. A low-wear, high-strength, high-conductivity copper alloy contact wire, characterized in that: The rod blank is made of a low-wear, high-strength and high-conductivity copper alloy material as claimed in claim 1, and then a contact line with a corresponding cross-sectional shape is obtained through processing.

3. A method for preparing a low-wear, high-strength, high-conductivity copper alloy contact wire, which is used to prepare a low-wear, high-strength, high-conductivity copper alloy contact wire as claimed in claim 2, characterized in that: The copper liquid is obtained by smelting according to the composition percentage of the low-wear, high-strength and high-conductivity copper alloy, and then cast into a rod billet, and then successively undergoes continuous extrusion, deformation treatment, aging treatment, forming, and deep cryogenic treatment processes to prepare a low-wear, high-strength and high-conductivity copper alloy contact wire with a set cross-sectional shape.

4. The method for preparing a low-wear, high-strength and high-conductivity copper alloy contact wire according to claim 3, characterized in that: It includes the following specific steps: S1. Melting and casting: using an electromagnetic induction furnace for melting and casting to obtain copper alloy cast rods, wherein the electromagnetic induction furnace includes: a melting zone, a transition zone, and an upper continuous casting zone, and the electromagnetic induction technology makes the copper solution composition evenly distributed; S2, continuous extrusion, using a continuous extruder to make the copper-chromium-zirconium alloy cast rod into a copper alloy extruded rod with a diameter of 20-32 mm; S3, cold deformation, subjecting a copper alloy extruded rod with a diameter of 20-32 mm to a cold deformation treatment of 0-65%; S4, aging treatment, bright aging treatment of copper and alloy rod blanks after cold deformation; S5, drawing and forming, drawing the copper alloy rod blank after aging treatment into a contact line of required size; S6. Cryogenic treatment: the copper alloy contact wire is put into a continuous cryogenic treatment device for online cryogenic treatment.

5. The method for preparing a low-wear, high-strength and high-conductivity copper alloy contact wire according to claim 1, characterized in that: Step S1: smelting and casting comprises the following steps: S101 oven; S102 smelting, high purity cathode copper plate is added to the smelting zone, the smelting furnace is heated to 1070±15℃, the copper plate is melted into copper liquid, and the copper liquid flows from the smelting zone to the transition zone and then to the upper continuous casting zone; S103 adding solvent, adding 0.05-0.1wt% sodium chloride to the copper liquid to prevent the melt from inhaling air, and then adding a solvent that has been deoxidized and dehydrated to the inner surface of the copper liquid, the solvent consisting of high-purity dehydrated borax, glass chips, soda ash and fluorite; S104: Install a crystallizer in the upward continuous casting area, remove the calcined charcoal and slag on the upper layer of the solvent in the upward continuous casting area, remove the solvent, and install one or more upward continuous casting crystallizers according to production needs; S105 adds Sn element, and uses anti-oxidation filler in the smelting area to add high-purity tin according to the alloy ratio; S106 purifies the solution, using an anti-oxygen filler in the smelting area to add dry Cu-18Mg and Cu-50Ca master alloys in accordance with the ratio requirements to remove oxygen from the copper liquid and other impurities in the smelting furnace; S107 dehydrogenation, in the smelting zone, 0.01-1wt% CuO powder is added into the furnace using an anti-oxidation filler to remove hydrogen from the copper liquid; S108 sampling and testing, sampling at multiple points in the upper continuous casting area to test the oxygen, hydrogen and impurity content of the copper alloy casting rod, if the standard is met, proceed to step S109, if not, proceed to step S106 or S107 appropriately according to the test results until the test results meet the standard; S109 adds Cr and Zr alloys, raises the temperature of the copper liquid to 1250°C-1300°C, first adds CuCr to the bottom of the copper liquid using an anti-oxygen filler according to the ratio, and after it is evenly distributed, adds CuZr to the bottom of the copper liquid using an anti-oxygen filler according to the ratio to make it evenly distributed; S110 secondary sampling and testing, sampling and testing the copper-chromium-zirconium alloy casting rods at multiple points in the upper continuous casting area, and after the composition meets the standard, multiple upper crystallizers start continuous upper casting. If the standard is not met, step S106 S107 or S109 is appropriately performed according to the test results until the test results meet the standard; S111 upward continuous casting, the crystallizer starts to be continuously pulled upward for casting, and the casting rod is cooled by rapid cooling at the same time; S112 Slag removal: During the smelting and upward continuous casting process, regular and rapid slag removal operations should be carried out according to actual conditions.

6. The method for preparing a low-wear, high-strength and high-conductivity copper alloy contact wire according to claim 4, characterized in that: Step S6 cryogenic treatment is to place the copper alloy contact wire in a continuous cryogenic treatment device for cryogenic treatment, and the cryogenic treatment is performed at least once. The continuous cryogenic treatment device includes at least one group of temperature adjustment chambers, at least one cryogenic treatment chamber, at least one circulating spray box, and at least one drying device; a wire take-up machine is arranged at the rear of the continuous cryogenic treatment device, and each group of temperature adjustment chambers includes at least two temperature adjustment chambers.

7. The method for preparing a low-wear, high-strength and high-conductivity copper alloy contact wire according to claim 6, characterized in that: The continuous cryogenic treatment device in step S6 is provided with several groups of temperature regulating chamber groups and several groups of cryogenic treatment chambers according to the performance requirements of the contact line. The contact line moves along the temperature regulating chamber group for staged cooling, enters the cryogenic treatment chamber for cryogenic operation, and then passes through a circulating spray box and a drying device for cooling and drying. According to the performance of the contact line, three options are made: option one, step-by-step cooling and deep cooling are performed again, and then the cryogenic treatment chamber is entered for deep cooling, and then the cryogenic treatment chamber is cooled and dried through a circulating spray box and a drying device; option two, directly enters the cryogenic treatment chamber again, and then passes through a circulating spray box and a drying device for cooling and drying; option three, is wound up by a wire take-up machine; the number of deep cooling times of the contact line is preset, and then the number of temperature regulating chamber groups and the number of cryogenic treatment chambers are preset, and the continuous cryogenic device is pre-assembled, and the contact line is guided to pass through the corresponding temperature regulating chamber group, cryogenic treatment chamber, circulating spray box, and drying device after drawing and forming, until it is finally wound up by the wire take-up machine.

8. The method for preparing a low-wear, high-strength and high-conductivity copper alloy contact wire according to claim 7, characterized in that: A spiral coil is provided in each temperature adjustment chamber. The spiral coil is arranged along the straight forward direction of the wire body. The wire body passes through the central cavity of the spiral coil. A horizontally arranged guide hub is provided in the cryogenic treatment chamber. The wire body passes through the center of the spiral coil of each temperature adjustment chamber in sequence and then enters the cryogenic treatment chamber. The single-layer spiral of the wire body surrounds the outer circumference of the guide hub and then is output in a straight line state.

9. The method for preparing a low-wear, high-strength and high-conductivity copper alloy contact wire according to claim 8, characterized in that: In step S6, the single cryogenic treatment temperature of the contact wire is -100°C to -190°C, and the time is 5 to 30 minutes. The single cryogenic time is controlled by adjusting the wire taking-up speed of the wire taking-up machine, the number of turns of the wire wound on the guide hub in the cryogenic treatment chamber, and the outer diameter of the guide hub.

10. The method for preparing a low-wear, high-strength and high-conductivity copper alloy contact wire according to claim 5, characterized in that: The standards for oxygen, hydrogen and impurity contents in step S108 are: oxygen mass percentage ≤ 0.0005%, hydrogen mass percentage ≤ 0.0005%, and impurity content ≤ 0.05%.

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