Aluminum alloy rod for high bending performance aluminum alloy conductor and preparation method and application thereof

Abstract

The present application relates to the technical field of aluminum alloy conductors, and specifically discloses an aluminum alloy rod for aluminum alloy conductors with high bending performance, and a preparation method and application thereof. The aluminum alloy rod is composed of the following elements: Fe, Cu, Mn, Si, Ni, Zn, Mg, Ti, B, rare earth elements, Al; the preparation method thereof is: adding aluminum ingots to a furnace to melt into aluminum liquid; blowing a refining agent into the aluminum liquid by nitrogen, and adding aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots and aluminum-iron alloy ingots to the aluminum liquid in turn, stirring and keeping warm; casting the obtained aluminum alloy liquid for final shaping; rolling to form an aluminum alloy rod. The aluminum alloy rod can be used to prepare aluminum alloy conductors. The aluminum alloy rod provided in the present application meets the requirements of the composition of 8030 aluminum alloy rods in GB / T 3954‑2014, and the aluminum alloy monofilaments produced therefrom have excellent bending performance after twisting and annealing.

Description

Technical Field

[0001] The present application relates to the technical field of aluminum alloy conductors, and more specifically, to an aluminum alloy rod for an aluminum alloy conductor with high bending performance, and a preparation method and application thereof. Background Art

[0002] my country's annual copper consumption for wires and cables is huge, and the import dependence is 70%, while the domestic primary aluminum production capacity is in excess and the product inventory is large. The promotion and application of aluminum alloy cable products can reduce copper consumption, resolve electrolytic aluminum production capacity, reduce electrolytic aluminum inventory pressure, and improve the effective utilization of resources. Aluminum alloy conductors are emerging conductor materials formed by adding rare earth, magnesium, copper, iron and other elements to pure aluminum through alloying processes. "GB / T3956-2008 Cable Conductors" specifies the nominal cross-sectional area of ​​0.5mm 2 ~2500mm 2 The conductors used in power cables and cords are divided into four categories. The first category is solid conductors, the second category is stranded conductors, the fifth category is soft conductors, and the sixth category is conductors that are softer than the fifth category. The first and second category conductors are used in cables for fixed laying, and the fifth and sixth category conductors are used in soft cables and cords, and can also be used for fixed laying.

[0003] 8030 aluminum alloy conductor belongs to the second type of conductor mentioned above. 8030 aluminum alloy rod is made according to the aluminum alloy composition specified by the American Society for Testing and Materials standard ASTMB800. Its main characteristic is good creep resistance and it is suitable for manufacturing products for electrical purposes.

[0004] At present, the preparation method of 8030 aluminum alloy conductor is generally to prepare a thicker aluminum alloy rod by melting and casting, and then draw the rod into aluminum alloy filaments of various diameters as needed, and then twist the aluminum alloy filaments into aluminum alloy conductors, and finally soften the aluminum alloy conductors through annealing process for subsequent processing. The advantage of this is that the diameter of the aluminum alloy rod can reach 9-10mm. Compared with aluminum alloy filaments with a diameter of 1-3mm, it is much easier to cast and easier to store. After the aluminum alloy rod is made, it can be drawn into filaments of various diameters at will, which is particularly convenient in processing. However, there are many problems with this. After being drawn into filaments, due to the change in crystal structure, the physical properties of the filaments are very different from those of the rods, especially the bending performance, which cannot meet the requirements of repeated dragging and bending of cables during actual installation and laying. Summary of the invention

[0005] In order to improve the problem that the current 8030 aluminum alloy conductor cable cannot meet the requirements of repeated dragging and bending during actual installation and laying, the present application provides an aluminum alloy rod for a high-bending performance aluminum alloy conductor and a preparation method and application thereof.

[0006] In the first aspect, the present application provides an aluminum alloy rod for an aluminum alloy conductor with high bending performance, which adopts the following technical solution:

[0007] An aluminum alloy rod for an aluminum alloy conductor with high bending performance is composed of the following elements in percentage by mass: Fe: 0.35% to 0.42%, Cu: 0.15% to 0.19%, Mn: 0.0020% to 0.0025%,

[0008] Si: 0.065% ~ 0.075%, Ni: 0.002% ~ 0.003%, Zn: 0.003% ~ 0.004%,

[0009] Mg: 0.0004% ~ 0.0005%, Ti: 0.001% ~ 0.002%, B: 0.001% ~ 0.002%,

[0010] Rare earth elements: 0.008% to 0.016%, the balance being Al.

[0011] By optimizing the formula of aluminum alloy rods, iron can improve the creep resistance and compression of the conductor, avoiding the relaxation problem caused by creep; copper can increase the resistance stability of the alloy at high temperatures; and magnesium can improve the contact point and have higher tensile strength under the same interface pressure.

[0012] The present application further optimizes the content of iron and copper elements, thereby ensuring that the aluminum alloy rod still has good bending performance and conductor conductivity after wire drawing and twisting.

[0013] In a second aspect, the present application provides a method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance, using the following technical solution:

[0014] A method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance comprises the following steps:

[0015] Step S1: adding an aluminum ingot into a melting furnace, setting the melting furnace temperature to 700° C. to 800° C., preferably 800° C., to melt the aluminum ingot into aluminum liquid;

[0016] Step S2: adopting a combined refining method, blowing a refining agent into the aluminum liquid through nitrogen, and then sequentially adding an aluminum-copper alloy ingot, a first-grade boron aluminum, a magnesium ingot, a rare earth alloy ingot and an aluminum-iron alloy ingot into the aluminum liquid and stirring the ingot using a permanent magnetic stirring device, and then performing a heat preservation treatment to obtain an aluminum alloy liquid;

[0017] Step S3: The aluminum alloy liquid obtained in step S2 is first sent to a large casting fort to filter impurities, so as to further improve the purity of the aluminum alloy liquid, and then cast into a small casting fort to cool and shape to obtain an aluminum alloy casting bar. When the casting bar temperature drops to 520° C., it can be judged that it has been cooled and formed;

[0018] Step S4: The aluminum alloy cast bar obtained in step S3 is introduced into a rolling mill for rolling. After 14 rolling processes, an aluminum alloy rod of a target size is finally formed.

[0019] This application adopts a combined refining method, using nitrogen to blow the refining agent into the aluminum liquid to remove hydrogen and other impurities in the aluminum liquid. The refining agent can penetrate deep into the aluminum liquid and spread quickly, thereby greatly increasing the contact area with the aluminum liquid, achieving the maximum degree of full contact and full reaction, and improving the effective utilization rate of the refining agent. At the same time, the nitrogen bubbles can also play a degassing role, thereby significantly improving the refining effect.

[0020] In the present application, the aluminum-iron alloy ingot is added to the aluminum liquid after other raw materials during the feeding process, which can avoid adsorption between the iron element and the permanent magnetic stirring equipment and prevent the elements in the aluminum alloy liquid from being dispersed unevenly.

[0021] Preferably, the stirring process in step S2 includes a first stirring process, a standing process and a second stirring process performed in sequence.

[0022] By configuring a static treatment during the two stirring treatments, the adsorption between the iron element and the permanent magnetic stirring equipment can be further prevented. The iron element can be desorbed from the permanent magnetic stirring equipment during the static time, ensuring that the aluminum liquid and the added elements are fully and evenly mixed.

[0023] Preferably, the time for the first stirring treatment and the second stirring treatment is 20 to 25 minutes respectively, and the time for the static treatment is 1 to 2 minutes.

[0024] By adopting the above technical solution, under the premise of ensuring that each element in the aluminum alloy liquid is dispersed more evenly, the corrosion of the aluminum element by the iron element after a long period of stirring can be avoided.

[0025] Preferably, the temperature of the heat preservation treatment in step S2 is 750° C. to 800° C., more preferably 760° C., and the heat preservation time is 20 to 25 minutes, more preferably 20 minutes.

[0026] By adopting heat preservation treatment after stirring treatment, the various elements in the aluminum alloy liquid can be fully mixed.

[0027] Preferably, the rare earth alloy ingot is a lanthanum-cerium rare earth alloy ingot, wherein the mass percentage of cerium element is 60%, the mass percentage of lanthanum element is 39%, and the mass percentage of other mixed rare earth elements is 1%.

[0028] By adopting the above technical solution, rare earth can improve the mechanical properties of the alloy, increase the electrical conductivity of the alloy, and improve the resistance to electrochemical corrosion.

[0029] Preferably, in step S4, an emulsion is used to cool the equipment and the aluminum alloy rod obtained by rolling during the rolling process, the emulsion temperature is 40-50°C, more preferably 50°C, and the coolant injection pressure is 0.5-1.0Mpa, more preferably 0.5Mpa.

[0030] By adopting the above technical scheme, the surface temperature of the equipment can be reduced, the thermal shock of the aluminum alloy rod on the equipment surface can be reduced, and the generation of cracks can be reduced; the temperature difference between the inside and outside of the roller can be reduced, the thermal stress of the roller can be reduced, and the roller breakage can be prevented; at the same time, the secondary iron oxide scale on the surface of the rolled material can be removed to prevent it from being embedded in the surface of the rolled material and affecting the surface quality of the rolled material, and to prevent it from being embedded in the roll gap and causing damage to the roll surface; the temperature of the rolled material can be properly controlled to prevent the temperature of the rolled material from becoming higher and higher and changing the performance; and a lubrication effect can be formed between the rolled material and the equipment to improve the wear resistance of the roller.

[0031] Preferably, the amount of the refining agent added is 0.1% to 0.2% of the mass of the aluminum liquid, and more preferably 0.1%.

[0032] By adopting the above technical solution, the oxides in the aluminum liquid can be effectively removed, the aluminum slag can be purified, and the working environment for melting the aluminum alloy can be improved.

[0033] In a third aspect, the present application provides an application of an aluminum alloy rod, using the following technical solution:

[0034] As described above, the aluminum alloy rod can be used to form an aluminum alloy conductor for a cable core after being subjected to wire drawing, twisting and annealing.

[0035] By adopting the above technical scheme, the aluminum alloy conductor single wire produced has excellent bending performance and can meet the requirement of single wire bending times ≥ 25 times stipulated in GB / T31840.1-2015. The aluminum alloy cable produced by this kind of aluminum alloy conductor has excellent bending resistance, which is more conducive to repeated dragging and bending of the cable during actual installation and laying, and is more practical.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. By optimizing the formula of aluminum alloy rods, iron can improve the creep resistance and compression of the conductor, avoiding the relaxation problem caused by creep; copper can increase the resistance stability of the alloy at high temperatures; magnesium can improve the contact point and have higher tensile strength under the same interface pressure.

[0038] 2. The method for preparing the aluminum alloy rod of the present application adds the aluminum-iron alloy ingot to the aluminum liquid after other raw materials during the feeding process, which can avoid the adsorption between the iron element and the permanent magnetic stirring device and prevent the various elements in the aluminum alloy liquid from being dispersed unevenly. By configuring a static treatment during the two stirring treatments, the adsorption between the iron element and the permanent magnetic stirring device can be further prevented. The static time can be used to desorb the iron element from the permanent magnetic stirring device and mix it more evenly with other elements.

[0039] 3. The aluminum alloy conductor single wire produced using the aluminum alloy rod of the present application has excellent bending performance and can meet the requirement of single wire bending times ≥ 25 times specified in GB / T31840.1-2015. The aluminum alloy cable produced using this aluminum alloy conductor has excellent bending resistance, which is more conducive to repeated dragging and bending of the cable during actual installation and laying, and is more practical. DETAILED DESCRIPTION

[0040] The present application is further described in detail below with reference to the embodiments.

[0041] The raw materials involved in the following examples of this application include:

[0042] Aluminum ingot: The manufacturer is Shanghai Liuze International Trade Co., Ltd., and the aluminum content in the aluminum ingot is ≥99.80%;

[0043] Aluminum-copper alloy ingot: The manufacturer is Xuzhou Jinlong Aluminum Co., Ltd. The copper content of the aluminum-copper alloy ingot is ≥50%, the iron content is ≤0.45%, and the silicon content is ≤0.20%;

[0044] Aluminum-iron alloy ingot: The manufacturer is Xuzhou Jinlong Aluminum Co., Ltd. The iron content of the aluminum-iron alloy ingot is ≥10.0%, and the silicon content is ≤0.20%;

[0045] Magnesium ingot: The manufacturer is Xuzhou Jinlong Aluminum Co., Ltd., and the magnesium content in the magnesium ingot is ≥99.90%;

[0046] First-grade boron aluminum: The manufacturer is Xuzhou Jinlong Aluminum Co., Ltd. The boron content of first-grade boron aluminum is 2.50% to 3.50%, the iron content is ≤0.40%, and the silicon content is ≤0.20%;

[0047] Rare earth alloy ingots: The manufacturer is Xuzhou Jinlong Aluminum Co., Ltd. The rare earth elements in the rare earth alloy ingots are ≥10%, of which the mass percentage of cerium is about 60%, the mass percentage of lanthanum is about 39%, and the mass percentage of other mixed rare earth elements is about 1%. The mass percentage of silicon in the rare earth alloy ingots is ≤0.20%;

[0048] Refining agent: The main ingredient is sodium nitrate, and the sodium nitrate content is ≥99%.

[0049] Example 1

[0050] Embodiment 1 provides an aluminum alloy rod for an aluminum alloy conductor with high bending performance, which is composed of the following elements in mass percentage: Fe: 0.35%, Cu: 0.15%, Mn: 0.002%, Si: 0.07%, Ni: 0.002%, Zn: 0.004%, Mg: 0.0004%, Ti: 0.001%, B: 0.001%, rare earth elements: 0.01%, and the balance is Al.

[0051] Prepare corresponding weights of raw materials according to the above proportions, including: aluminum ingots, aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots, aluminum-iron alloy ingots and refining agents.

[0052] The preparation process of the aluminum alloy rod for the high bending performance aluminum alloy conductor is as follows:

[0053] Step S1: adding an aluminum ingot into a melting furnace, setting the furnace temperature to 800° C., and melting the aluminum ingot into aluminum liquid;

[0054] Step S2: adopting a combined refining method, blowing a refining agent into the aluminum liquid through nitrogen, wherein the amount of the refining agent added is 0.1% of the mass of the aluminum liquid, and then sequentially adding an aluminum-copper alloy ingot, a first-level boron aluminum, a magnesium ingot, a rare earth alloy ingot and an aluminum-iron alloy ingot into the aluminum liquid, performing two stirring treatments and arranging a static treatment between the two stirring treatments, wherein the first stirring treatment time is 20 minutes, the static treatment time is 1 minute, the second stirring treatment time is 20 minutes, and finally heat-insulating treatment is performed at a temperature of 760° C. for 20 minutes to obtain an aluminum alloy liquid;

[0055] Step S3: The aluminum alloy liquid obtained in step S2 is first sent to a large casting cask for impurity filtration, and then cast into a small casting cask for cooling and shaping to obtain an aluminum alloy casting bar with a width of 60 mm and a height of 43 mm, wherein the casting speed is set to a control ratio of 75%, and the casting liquid temperature is about 730°C;

[0056] Step S4: The aluminum alloy cast bar obtained in step S3 is introduced into a rolling mill for rolling. During the rolling process, an emulsion is used to cool the equipment and the aluminum alloy rod obtained by rolling. The emulsion temperature is 50°C, and the coolant injection pressure is 0.5 MPa, ultimately forming an aluminum alloy rod with a target diameter of 9.5 mm.

[0057] Example 2

[0058] The preparation process of Example 2 is the same as that of Example 1, and the only difference is that the element ratio is different. The aluminum alloy rod for high bending performance aluminum alloy conductor in Example 2 is composed of the following elements in mass percentage:

[0059] Fe: 0.35%, Cu: 0.19%, Mn: 0.002%, Si: 0.07%, Ni: 0.002%, Zn: 0.004%, Mg: 0.0004%, Ti: 0.001%, B: 0.001%, rare earth elements: 0.01%, and the balance is Al.

[0060] Example 3

[0061] The preparation process of Example 3 is the same as that of Example 1, and the only difference is that the element ratio is different. The aluminum alloy rod for high bending performance aluminum alloy conductor in Example 3 is composed of the following elements in mass percentage:

[0062] Fe: 0.4%, Cu: 0.15%, Mn: 0.002%, Si: 0.07%, Ni: 0.002%, Zn: 0.004%, Mg: 0.0004%, Ti: 0.001%, B: 0.001%, rare earth elements: 0.01%, and the balance is Al.

[0063] Example 4

[0064] The preparation process of Example 4 is the same as that of Example 1, and the only difference is that the element ratio is different. The aluminum alloy rod for high bending performance aluminum alloy conductor in Example 4 is composed of the following elements in mass percentage:

[0065] Fe: 0.42%, Cu: 0.15%, Mn: 0.002%, Si: 0.07%, Ni: 0.002%, Zn: 0.004%, Mg: 0.0004%, Ti: 0.001%, B: 0.001%, rare earth elements: 0.01%, and the balance is Al.

[0066] Example 5

[0067] The preparation process of Example 5 is the same as that of Example 1, and the only difference is that the element ratio is different. The aluminum alloy rod for high bending performance aluminum alloy conductor in Example 5 is composed of the following elements in mass percentage:

[0068] Fe: 0.4%, Cu: 0.19%, Mn: 0.0025%, Si: 0.075%, Ni: 0.003%, Zn: 0.003%, Mg: 0.0005%, Ti: 0.002%, B: 0.002%, rare earth elements: 0.008%, and the balance is Al.

[0069] Example 6

[0070] The preparation process of Example 6 is the same as that of Example 1, and the only difference is that the element ratio is different. The aluminum alloy rod for high bending performance aluminum alloy conductor in Example 6 is composed of the following elements in mass percentage:

[0071] Fe: 0.4%, Cu: 0.19%, Mn: 0.0025%, Si: 0.065%, Ni: 0.003%, Zn: 0.003%, Mg: 0.0005%, Ti: 0.002%, B: 0.002%, rare earth elements: 0.016%, and the balance is Al.

[0072] Example 7

[0073] The element ratio of Example 7 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Example 7 is as follows:

[0074] A combined refining method is adopted, in which the refining agent is blown into the aluminum liquid by nitrogen, and then aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots and aluminum-iron alloy ingots are added to the aluminum liquid in turn, and two stirring treatments are carried out, and a standing treatment is arranged between the two stirring treatments. The first stirring treatment time is 25 minutes, the standing treatment time is 1 minute, the second stirring treatment time is 25 minutes, and finally the aluminum alloy liquid is obtained by heat preservation treatment at 760°C for 20 minutes.

[0075] Example 8

[0076] The element ratio of Example 8 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Example 8 is as follows:

[0077] A combined refining method is adopted, in which the refining agent is blown into the aluminum liquid by nitrogen, and then aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots and aluminum-iron alloy ingots are added to the aluminum liquid in turn, and two stirring treatments are performed, and a standing treatment is arranged between the two stirring treatments. The first stirring treatment time is 25 minutes, the standing treatment time is 2 minutes, the second stirring treatment time is 25 minutes, and finally the aluminum alloy liquid is obtained by heat preservation treatment at 760°C for 20 minutes.

[0078] Example 9

[0079] The element ratio of Example 9 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Example 9 is as follows:

[0080] A combined refining method is adopted, in which the refining agent is blown into the aluminum liquid by nitrogen, and then aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots and aluminum-iron alloy ingots are added to the aluminum liquid in turn, and two stirring treatments are performed and a standing treatment is arranged between the two stirring treatments. The first stirring treatment time is 20 minutes, the standing treatment time is 1 minute, the second stirring treatment time is 25 minutes, and finally the aluminum alloy liquid is obtained by heat preservation treatment at 760°C for 20 minutes.

[0081] Example 10

[0082] The element ratio of Example 10 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Example 10 is as follows:

[0083] A combined refining method is adopted, in which the refining agent is blown into the aluminum liquid by nitrogen, and then aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots and aluminum-iron alloy ingots are added to the aluminum liquid in turn, and two stirring treatments are performed and a standing treatment is arranged between the two stirring treatments. The first stirring treatment time is 20 minutes, the standing treatment time is 1 minute, the second stirring treatment time is 25 minutes, and finally the aluminum alloy liquid is obtained by heat preservation treatment at 760°C for 20 minutes.

[0084] Embodiment 11

[0085] The element ratio of Example 11 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Example 11 is as follows:

[0086] A combined refining method is adopted, in which the refining agent is blown into the aluminum liquid by nitrogen, and then aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots and aluminum-iron alloy ingots are added to the aluminum liquid in turn, and two stirring treatments are performed and a standing treatment is arranged between the two stirring treatments. The first stirring treatment time is 20 minutes, the standing treatment time is 2 minutes, the second stirring treatment time is 20 minutes, and finally the aluminum alloy liquid is obtained by heat preservation treatment at 760°C for 20 minutes.

[0087] Comparative Example 1

[0088] Comparative Example 1 provides an 8030 aluminum alloy rod. The preparation process of Comparative Example 1 is the same as that of Example 1, except that the element ratio is different. The 8030 aluminum alloy rod in Comparative Example 1 is composed of the following elements in mass percentage: Fe: 0.45%, Cu: 0.20%, Mn: 0.003%, Si: 0.09%, Ni: 0.003%, Zn: 0.005%, Mg: 0.0008%, Ti: 0.005%, B: 0.003%, rare earth element: 0.01%, and the balance is Al.

[0089] Comparative Example 2

[0090] Comparative Example 2 provides an 8030 aluminum alloy rod. The preparation process of Comparative Example 2 is the same as that of Example 1, except that the element ratio is different. The 8030 aluminum alloy rod in Comparative Example 2 is composed of the following elements in mass percentage: Fe: 0.55%, Cu: 0.25%, Mn: 0.004%, Si: 0.12%, Ni: 0.005%, Zn: 0.007%, Mg: 0.0012%, Ti: 0.008%, B: 0.005%, rare earth element: 0.01%, and the balance is Al.

[0091] Comparative Example 3

[0092] The element ratio of Comparative Example 3 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Comparative Example 3 is as follows:

[0093] A combined refining method is adopted, in which the refining agent is blown into the aluminum liquid by nitrogen, and then aluminum-iron alloy ingots, aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots and rare earth alloy ingots are added to the aluminum liquid in turn, and two stirring treatments are carried out, and a standing treatment is arranged between the two stirring treatments. The first stirring treatment time is 20 minutes, the standing treatment time is 1 minute, the second stirring treatment time is 20 minutes, and finally the aluminum alloy liquid is obtained by heat preservation treatment at 760°C for 20 minutes.

[0094] Comparative Example 4

[0095] The element ratio of Comparative Example 4 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Comparative Example 4 is as follows:

[0096] A combined refining method is adopted, in which the refining agent is blown into the aluminum liquid by nitrogen, and then aluminum-copper alloy ingots, aluminum-iron alloy ingots, primary boron aluminum, magnesium ingots and rare earth alloy ingots are added to the aluminum liquid in turn, and two stirring treatments are carried out, and a standing treatment is arranged between the two stirring treatments. The first stirring treatment time is 20 minutes, the standing treatment time is 1 minute, the second stirring treatment time is 20 minutes, and finally the aluminum alloy liquid is obtained by heat preservation treatment at 760°C for 20 minutes.

[0097] Comparative Example 5

[0098] The element ratio of Comparative Example 5 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Comparative Example 5 is as follows:

[0099] A combined refining method is adopted, in which the refining agent is blown into the aluminum liquid through nitrogen, and then aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots and aluminum-iron alloy ingots are added to the aluminum liquid in turn for stirring. The stirring time is 40 minutes, and finally the aluminum liquid is heat-insulated at 760°C for 20 minutes to obtain the aluminum alloy liquid.

[0100] Comparative Example 6

[0101] The element ratio of Comparative Example 6 is the same as that of Example 1, and the only difference is that step S2 of the preparation process is different. Step S2 of Comparative Example 6 is as follows:

[0102] Aluminum-copper alloy ingots, primary boron aluminum, magnesium ingots, rare earth alloy ingots, aluminum-iron alloy ingots and refining agents are added to the aluminum liquid in turn, and stirred twice with a standing treatment between the two stirring treatments. The first stirring treatment time is 20 minutes, the standing treatment time is 1 minute, the second stirring treatment time is 20 minutes, and finally the aluminum alloy liquid is obtained by heat preservation treatment at 760°C for 20 minutes.

[0103] Application Examples

[0104] The aluminum alloy rods with a diameter of 9.5 mm prepared in the above Examples 1-11 and Comparative Examples 1-6 were used to prepare 120 mm 2 Aluminum alloy conductor and 240mm 2 Aluminum alloy conductor. The specific preparation method is as follows:

[0105] A. Wire drawing: The aluminum alloy rods prepared in the above-mentioned Examples 1-11 and Comparative Examples 1-6 are respectively subjected to wire drawing by an aluminum drawing machine to obtain aluminum alloy monofilaments with nominal diameters of 2.90 mm and 2.85 mm, respectively, for use, and each coil of monofilaments is about 3.5 km;

[0106] B. Twisting: 120mm 2 The aluminum alloy conductor adopts 1+6+12 regular stranding, using a single wire with a nominal diameter of 2.85mm, the inner diameter of the 1+6 compression die is 8.1mm, the +12 compression die size is 13.4mm, the conductor inner layer twisting pitch diameter ratio is 25 times, the outer layer twisting pitch diameter ratio is 12 times, and the stranding line speed is 20m / min; 240mm 2 The aluminum alloy conductor adopts 1+6+12+18 regular stranding, using a single wire with a nominal diameter of 2.90mm, the inner diameter of the 1+6 compression die is 8.2mm, the +12 compression die size is 13.4mm, the +18 compression die size is 18.6mm, the conductor inner layer twisting pitch diameter ratio is 25 times, the outer layer twisting pitch diameter ratio is 12 times, and the stranding line speed is 16m / min;

[0107] C. Annealing: 120mm 2 and 240mm 2Each aluminum alloy conductor uses a hollow annealing disc with a diameter of 2.0m, and each disc contains 3km of conductor. The two discs of conductor are placed in two annealing furnaces respectively, and the annealing temperature is set to 330℃ and 120mm 2 The aluminum alloy conductor is heated for 1.5 hours, heated to 330℃ and kept warm for 4 hours. After the insulation is completed, the furnace is powered off and the tank is sealed for 0.5 hours; 240mm 2 The aluminum alloy conductor is heated for 1.5 hours, heated to 330℃ and kept warm for 5 hours. After the heat preservation, the furnace is powered off and sealed for 0.5 hours. After the sealing, the furnace door is opened, and the two coils of conductor are taken out and cooled at room temperature for 24 hours to obtain 120mm 2 and 240mm 2 Aluminum alloy conductor.

[0108] Performance Testing

[0109] The two specifications of aluminum alloy conductors after annealing in the above application example were subjected to bending performance test, tensile performance test and conductivity test respectively. 2 The bending performance test results of aluminum alloy conductors are shown in Table 1, 120mm 2 The tensile properties and conductivity test results of aluminum alloy conductors are shown in Table 3. 2 The bending performance test results of aluminum alloy conductors are shown in Table 2. 2 The tensile properties and conductivity test results of the aluminum alloy conductor are shown in Table 4.

[0110] The test method is as follows:

[0111] 1. Bending performance

[0112] Take 5 1.5m long monofilaments of each specification of aluminum alloy conductor, of which 120mm 2 Take any 3 monofilaments from the outermost layer of the aluminum alloy conductor, 1 from the second outermost layer, and 1 from the center layer; 240mm 2 Take any two monofilaments from the outermost layer of the aluminum alloy conductor, one from the second outer layer, one from the second inner layer, and one from the center layer. Divide each monofilament into five sections, each 30 cm long. Place each section of monofilament in the test device of the motorized bending tester, adjust the bending speed to 60 times / min, use a bending cylinder with a diameter of 7.5 mm, a distance of 25 mm from the top surface of the support to the bottom surface of the guide block, and a lever hole with a diameter of 3.5 mm. Perform a bending test on each section of monofilament and take the average of the results of the five tests.

[0113] 2. Tensile properties

[0114] The tensile strength and elongation at break of the single wire in the center layer of the conductor are tested using a tensile testing machine.

[0115] 3. Conductor conductivity:

[0116] The conductivity of a conductor is measured using the bridge method.

[0117] Table 1 Bending properties (120 mm 2 Aluminum alloy conductor)

[0118]

[0119]

[0120] Table 2 Bending properties (240mm 2 Aluminum alloy conductor)

[0121]

[0122]

[0123] Table 3 Tensile properties and electrical conductivity (120 mm 2 Aluminum alloy conductor)

[0124]

[0125] Table 4 Tensile properties and electrical conductivity (240 mm 2 Aluminum alloy conductor)

[0126]

[0127] It can be seen from the results of Example 1 and Comparative Examples 1-2 that the contents of iron and copper in the aluminum alloy rods of Comparative Examples 1 and 2 are higher than those in Example 1. Although the mechanical properties of the aluminum alloy conductors made of the aluminum alloy rods of Comparative Examples 1-2 can meet general requirements, their bending properties still cannot meet the requirement that the number of single-wire bending times is ≥25 times, and the electrical conductivity of the obtained aluminum alloy conductors is <61.0% IACS.

[0128] It can be seen from the results of Example 1 and Comparative Examples 3-4 that during the process of adding raw materials in step S2, Comparative Examples 3 and 4 did not add the aluminum-iron alloy ingot in the last step, resulting in their bending performance being unable to meet the requirement of single wire bending times ≥ 25 times, and the conductivity of the obtained aluminum alloy conductor was <61.0% IACS.

[0129] It can be seen from the results of Example 1 and Comparative Example 5 that in step S2, the static treatment between the two stirring treatments was eliminated in Comparative Example 5, and the bending performance of the aluminum alloy rod obtained cannot meet the requirement that the number of single-wire bending times is ≥25 times, and the conductivity of the aluminum alloy conductor obtained is <61.0% IACS.

[0130] It can be seen from the results of Example 1 and Comparative Example 6 that in step S2 of Comparative Example 6, the electrical conductivity of the aluminum alloy conductor obtained is less than 61.0% IACS.

[0131] Therefore, the aluminum alloy rod provided in the present application meets the requirements of the composition of 8030 aluminum alloy rod in GB / T 3954-2014. After twisting and annealing, the aluminum alloy monofilament produced has excellent bending performance and can meet the requirement of ≥25 times of single wire bending specified in GB / T31840.1-2015. The aluminum alloy cable produced by this aluminum alloy conductor has excellent bending resistance, is more conducive to repeated dragging and bending of the cable during actual installation and laying, and is more practical.

[0132] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An aluminum alloy rod for an aluminum alloy conductor with high bending performance, characterized in that: It is composed of the following elements in percentage by mass: Fe: 0.35%~0.42%, Cu: 0.15%~0.19%, Mn: 0.0020%~0.0025%, Si: 0.065%~0.075%, Ni: 0.002%~0.003%, Zn: 0.003%~0.004%, Mg: 0.0004%~0.0005%, Ti: 0.001%~0.002%, B: 0.001%~0.002%, Rare earth elements: 0.008%~0.016%, the balance is Al.

2. A method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance as claimed in claim 1, characterized in that: The steps include: Step S1: adding aluminum ingots into a furnace, setting the furnace temperature to 700°C to 800°C, and melting the aluminum ingots into aluminum liquid; Step S2: adopting a combined refining method, blowing a refining agent into the aluminum liquid through nitrogen, and then sequentially adding an aluminum-copper alloy ingot, a first-grade boron aluminum, a magnesium ingot, a rare earth alloy ingot and an aluminum-iron alloy ingot into the aluminum liquid and stirring the ingot using a permanent magnetic stirring device, and then performing a heat preservation treatment to obtain an aluminum alloy liquid; Step S3: The aluminum alloy liquid obtained in step S2 is first sent to a large casting fort to filter out impurities, and then cast into a small casting fort to cool and shape to obtain an aluminum alloy casting bar; Step S4: introducing the aluminum alloy cast bar obtained in step S3 into a rolling mill for rolling to form an aluminum alloy rod of a target size.

3. The method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance according to claim 2, characterized in that: The stirring process in step S2 includes a first stirring process, a standing process and a second stirring process performed in sequence.

4. The method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance according to claim 3, characterized in that: The time for the first stirring treatment and the second stirring treatment is 20 to 25 minutes respectively, and the time for the static treatment is 1 to 2 minutes.

5. The method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance according to claim 2, characterized in that: The temperature of the heat preservation treatment in step S2 is 750° C. to 800° C., and the heat preservation time is 20 to 25 minutes.

6. The method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance according to claim 2, characterized in that: The rare earth alloy ingot is a lanthanum-cerium rare earth alloy ingot, wherein the mass percentage of cerium element is 60%, the mass percentage of lanthanum element is 39%, and the mass percentage of other mixed rare earth elements is 1%.

7. The method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance according to claim 2, characterized in that: In step S4, during the rolling process, an emulsion is used to cool the equipment and the aluminum alloy rod obtained by rolling, the emulsion temperature is 40° C. to 50° C., and the coolant injection pressure is 0.5 to 1.0 MPa.

8. The method for preparing an aluminum alloy rod for an aluminum alloy conductor with high bending performance according to claim 2, characterized in that: The amount of the refining agent added is 0.1% to 0.2% of the mass of the aluminum liquid.

9. The use of the aluminum alloy rod according to claim 1, characterized in that: The aluminum alloy rod can be formed into an aluminum alloy conductor for a cable core after being subjected to wire drawing, twisting and annealing.

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