Preparation method of high-conductivity heat-resistant aluminum alloy wire

Abstract

The invention relates to a preparation method of a high-conductivity heat-resistant aluminum alloy wire, and belongs to the technical field of aluminum alloy wires. The aluminum-iron alloy, the aluminum-boron alloy, the aluminum-yttrium alloy, the rare earth alloy and the aluminum-zirconium alloy are added into the aluminum ingot, it is ensured that aluminum alloy melt has the proper trace element content, and the trace elements can effectively improve the electric conductivity and heat resistance of the aluminum alloy; the on-line refining agent and aging treatment are applied to further refine grains, and the obtained monofilament has more excellent resistivity and heat resistance under the condition that the strength is kept, keeps the strength at high temperature and has excellent tensile strength.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy wires and relates to a method for preparing a high-conductivity heat-resistant aluminum alloy wire. Background Art

[0002] The transmission network plays a vital role in the national economic construction. With the rapid development of the national economy, more transmission lines need to be built. The construction of new lines requires land, poles, wires and their accessories. Land resources are becoming increasingly precious. When expanding the transmission capacity, land should be saved. In addition, the original transmission lines have been used for more than 40 years or longer, and have reached or are close to their service life. They need to be updated. At the same time, the transmission capacity may need to be increased according to actual needs. In addition, in addition to transmitting stable thermal power generation energy, the transmission network also transmits hydropower whose total energy varies with different seasons, and transmits solar energy and wind energy that often changes due to sunlight and wind. Therefore, the transmission network lines and wires should be able to meet these new requirements.

[0003] There are two ways to increase the capacity of existing transmission lines: one is to increase the conductor cross-section; the other is to use heat-resistant conductors. Increasing the conductor cross-section requires strengthening the existing towers, while using heat-resistant conductors does not require strengthening the existing towers. Under the conditions of existing line corridors and facilities, replacing the currently used overhead steel-core aluminum stranded wires with high-conductivity heat-resistant aluminum alloy conductors is an effective way to increase line transmission capacity and reduce line losses.

[0004] In China, after decades of development, overhead transmission lines have become more mature, especially the aluminum-magnesium-silicon high-strength series and heat-resistant aluminum alloy series. At the same time, there have been great improvements in equipment. At present, domestic special conductors are mainly developing in the direction of lighter weight, better conductivity, higher strength, and can adapt to more special environments. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing a high-conductivity heat-resistant aluminum alloy wire, which has the characteristics of high conductivity and heat resistance.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing a high-conductivity heat-resistant aluminum alloy wire, the specific process of the method for preparing a high-conductivity heat-resistant aluminum alloy wire is as follows: S1: The aluminum ingot is completely melted at 670-710°C, a slag remover is added, and the mixture is stirred at a speed of 150-250 r / min for 20-30 min. After the stirring is completed, the surface scum is removed, and a sample is taken for analysis. The temperature is raised to 755-765°C at a rate of 0.2-0.5°C / min, and aluminum-iron alloy, aluminum-boron alloy, aluminum-yttrium alloy, and rare earth alloy are added. The mixture is stirred at a speed of 200-300 r / min for 30-45 min to obtain a mixed alloy melt A. The aluminum-zirconium alloy is then added, and the speed is adjusted to 100-200 r / min. The stirring time is 30-45 min. After adding the degassing agent, the mixture is allowed to stand for 5-10 min. After removing the scum, a slag remover is added, and the mixture is stirred at 150-250 r / min for 20-30 min. The surface scum is removed, and the mixture is allowed to stand for 20 min. The mixture is sampled for analysis to obtain an aluminum alloy melt. S2: The aluminum alloy melt is degassed and filtered online by an online degassing and filtering system, and an aluminum-niobium-boron refining agent is added online to complete the online refining of the aluminum alloy melt. The aluminum alloy melt after online refining is poured into a wheel-type crystallizer for continuous casting to obtain a casting billet. The continuous casting temperature is 720-730°C. S3: transferring the ingot to a continuous rolling mill for continuous rolling, with a rolling temperature of 500-520°C, a rolling temperature of 300-350°C, and a rolling exit temperature of 170-200°C to obtain an aluminum alloy rod; S4: subjecting the aluminum alloy rod to a heating and aging treatment in an aging furnace, cooling the aluminum alloy rod to a temperature of 20-25° C., and then subjecting the aluminum alloy rod to wire drawing deformation at a speed of 12 m / s using a wire drawing machine to obtain an aluminum alloy single wire. After testing the obtained aluminum alloy single wire, the aluminum alloy single wire is subjected to a secondary aging treatment to obtain the high conductivity heat-resistant aluminum alloy wire.

[0007] Furthermore, the aluminum ingot in S1 is an aluminum ingot of grade Al99.85.

[0008] Furthermore, in the S1, the iron content of the aluminum-iron alloy is 5%, the boron content of the aluminum-boron alloy is 3%, the yttrium content of the aluminum-yttrium alloy is 5%, the rare earth content of the rare earth alloy is 10%, and the zirconium content of the aluminum-zirconium alloy is 5%.

[0009] Furthermore, the boron content in the mixed alloy melt A in S1 is ≤0.001%.

[0010] Furthermore, the amount of aluminum niobium boron refining agent added to the S2 is 0.15-0.2wt%.

[0011] Furthermore, in the S3, the rolling mill speed for continuous rolling is 450-460 r / min, the rolling mill current is 560-590 A, the rolling emulsion temperature is 35-43° C., and the rolling emulsion pressure is 0.2-0.24 MPa.

[0012] Furthermore, the temperature of the heat-resistant aluminum alloy rod obtained in S3 is 150-200°C.

[0013] Furthermore, the aging treatment parameters of the aluminum alloy rod in S4 are aging time 3-6h and aging temperature 230-300°C.

[0014] Furthermore, the secondary aging treatment parameters of the aluminum alloy single wire in S4 are aging time 3-4h and aging temperature 175-200°C.

[0015] Furthermore, the diameter of the high-conductivity heat-resistant aluminum alloy wire obtained in S4 is 3.99 mm.

[0016] The element components of the heat-resistant aluminum alloy rod material prepared by the present invention include, by mass percentage: Si 0.03-0.05%, Fe 0.08-0.015%, Cu less than 0.001%, B less than 0.001%, Mg less than 0.002%, Zn0.001-0.011%, Y 0.03-0.04%, Zr 0.02-0.035%, La, Ce rare earth 0.04-0.1%, Cr+Mn+V+Ti less than 0.004, and the balance is Al.

[0017] The slag cleaning agent in the present invention was purchased from Xuzhou Tiancheng Aluminum Co., Ltd., item number TC-LJ1; By adding aluminum-iron alloy, aluminum-boron alloy, aluminum-yttrium alloy, rare earth alloy and aluminum-zirconium alloy into the aluminum ingot, it is ensured that the aluminum alloy melt has an appropriate content of trace elements, which can effectively improve the conductivity and heat resistance of the aluminum alloy.

[0018] In the mixed alloy melt A, the boron content is strictly controlled at ≤0.001%, which helps to reduce the adverse effects of impurities on the performance of the aluminum alloy; at the same time, it reduces the reaction between the boron element and zirconium, consumes the zirconium content, and affects the heat resistance.

[0019] The aluminum-niobium-boron refining agent added in the present invention can effectively remove gases (such as hydrogen, oxygen, nitrogen, etc.) and tiny non-metallic inclusions in the aluminum alloy melt, which usually reduce the electrical conductivity and heat resistance of the aluminum alloy. Through refining, the purity and quality of the aluminum alloy can be significantly improved, thereby improving its physical and chemical properties. The active elements in the refining agent can react chemically with the impurities in the aluminum alloy to generate compounds that are easy to remove, thereby further reducing the adverse effects of impurities on electrical conductivity. Therefore, the addition of the aluminum-niobium-boron refining agent helps to improve the electrical conductivity of the aluminum alloy, and online refining can ensure that the aluminum alloy melt reaches the best purity and uniformity before casting, which helps to reduce defects that may occur during the casting process, such as pores, inclusions, etc. Therefore, the addition of the aluminum-niobium-boron refining agent can optimize the casting process and improve the quality of the ingot.

[0020] The present invention ensures the uniformity and purity of the aluminum alloy melt by precisely controlling the temperature, rotation speed and time during the melting, stirring and refining processes. The use of an online degassing and filtering system further improves the quality of the aluminum alloy melt and reduces the content of gas and inclusions. During continuous casting and continuous rolling, the uniformity and consistency of the aluminum alloy rod are ensured by controlling parameters such as temperature, rotation speed and current.

[0021] After aging treatment and wire drawing deformation, the aluminum alloy single wire of the present invention not only has excellent conductivity, but also has good heat resistance, and can meet the use requirements in high temperature environment. The secondary aging treatment further improves the comprehensive performance of the aluminum alloy wire and ensures the stability and reliability of the product.

[0022] Beneficial effects of the present invention: (1) The present invention ensures that the aluminum alloy melt has an appropriate content of trace elements by adding aluminum-iron alloy, aluminum-boron alloy, aluminum-yttrium alloy, rare earth alloy and aluminum-zirconium alloy to the aluminum ingot. These trace elements can effectively improve the electrical conductivity and heat resistance of the aluminum alloy. (2) The present invention uses an online refining agent and aging treatment to further refine the grains, and the obtained single fiber has a more excellent resistivity and heat resistance while maintaining strength, maintains strength at high temperatures, and has excellent tensile strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0024] Figure 1 Schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0025] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0026] Example 1 S1: The aluminum ingot of grade Al99.85 is completely melted at 690℃, a slag remover is added, and the mixture is stirred at a speed of 200r / min for 25min. After the stirring is completed, the surface scum is removed, and sampling is performed for analysis. The temperature is raised to 760℃ at a rate of 0.3℃ / min, and aluminum-iron alloy, aluminum-boron alloy, aluminum-yttrium alloy, and rare earth alloy are added. The mixture is stirred at a speed of 200r / min for 40min to obtain a mixed alloy melt A, in which the boron content of the mixed alloy melt A is ≤0.001%. Then, an aluminum-zirconium alloy is added, and the speed is adjusted to 100r / min. The stirring time is 45min. After adding the degassing agent, the mixture is allowed to stand for 10min. After removing the scum, a slag remover is added, and the mixture is stirred at 250r / min for 20min. The surface scum is removed, and the mixture is allowed to stand for 20min. Sampling is performed for analysis to obtain an aluminum alloy melt; Among them, the iron content in aluminum-iron alloy is 5%, the boron content in aluminum-boron alloy is 3%, the yttrium content in aluminum-yttrium alloy is 5%, the rare earth content in rare earth alloy is 10%, and the zirconium content in aluminum-zirconium alloy is 5%; S2: The aluminum alloy melt is degassed and filtered online by an online degassing and filtering system, 0.15wt% aluminum-niobium-boron refining agent is added online to complete the online refining of the aluminum alloy melt, and the aluminum alloy melt after online refining is poured into a wheel crystallizer for continuous casting to obtain a casting billet, and the continuous casting temperature is 720°C; S3: transferring the ingot to the continuous rolling mill for continuous rolling, wherein the rolling mill speed is 450r / min, the rolling mill current is 560A, the rolling emulsion temperature is 40°C, the rolling emulsion pressure is 0.2Mpa, the rolling entry temperature is 500°C, the rolling temperature is 300°C, and the rolling exit temperature is 170°C, to obtain an aluminum alloy rod with a temperature of 150°C; S4: subjecting the aluminum alloy rod to a heating aging treatment in an aging furnace, wherein the aging treatment parameters are an aging time of 6 hours and an aging temperature of 300°C, and after aging cooling to 25°C, a wire drawing machine is used to perform wire drawing deformation at a speed of 12 m / s to obtain an aluminum alloy single wire, and after the obtained aluminum alloy single wire is tested, a secondary aging treatment is performed on the aluminum alloy single wire, wherein the secondary aging treatment parameters are an aging time of 4 hours and an aging temperature of 200°C, to obtain the high conductivity heat-resistant aluminum alloy wire having a diameter of 3.99 mm.

[0027] Example 2 S1: The aluminum ingot of grade Al99.85 is completely melted at 670℃, a slag remover is added, and the mixture is stirred at a speed of 150r / min for 20min. After the stirring is completed, the surface scum is removed, and sampling is performed for analysis. The temperature is raised to 755℃ at a rate of 0.2℃ / min, and aluminum-iron alloy, aluminum-boron alloy, aluminum-yttrium alloy, and rare earth alloy are added. The mixture is stirred at a speed of 200r / min for 30min to obtain a mixed alloy melt A, in which the boron content of the mixed alloy melt A is ≤0.001%. Then, an aluminum-zirconium alloy is added, and the speed is adjusted to 100r / min. The stirring time is 30min. After adding the degassing agent, the mixture is allowed to stand for 5min. After removing the scum, a slag remover is added, and the mixture is stirred at 150r / min for 20min. The surface scum is removed, and the mixture is allowed to stand for 20min. Sampling is performed for analysis to obtain an aluminum alloy melt; Among them, the iron content in aluminum-iron alloy is 5%, the boron content in aluminum-boron alloy is 3%, the yttrium content in aluminum-yttrium alloy is 5%, the rare earth content in rare earth alloy is 10%, and the zirconium content in aluminum-zirconium alloy is 5%; S2: The aluminum alloy melt is degassed and filtered online by an online degassing and filtering system, 0.15wt% aluminum-niobium-boron refining agent is added online to complete the online refining of the aluminum alloy melt, and the aluminum alloy melt after online refining is poured into a wheel crystallizer for continuous casting to obtain a casting billet, and the continuous casting temperature is 720°C; S3: transferring the ingot to the continuous rolling mill for continuous rolling, wherein the rolling mill speed is 450r / min, the rolling mill current is 560A, the rolling emulsion temperature is 35°C, the rolling emulsion pressure is 0.2Mpa, the rolling entry temperature is 500°C, the rolling temperature is 300°C, the rolling exit temperature is 170°C, and the aluminum alloy rod with a temperature of 150°C is obtained; S4: subjecting the aluminum alloy rod to a heating aging treatment in an aging furnace, wherein the aging treatment parameters are an aging time of 3 hours and an aging temperature of 230°C, and after cooling to 20°C, subjecting the aluminum alloy rod to wire drawing deformation at a speed of 12 m / s using a wire drawing machine to obtain an aluminum alloy single wire, and subjecting the obtained aluminum alloy single wire to a secondary aging treatment, wherein the secondary aging treatment parameters are an aging time of 3 hours and an aging temperature of 175°C, to obtain the high conductivity heat-resistant aluminum alloy wire having a diameter of 3.99 mm.

[0028] Example 3 S1: The aluminum ingot of grade Al99.85 is completely melted at 710℃, a slag remover is added, and the mixture is stirred at a speed of 250r / min for 30min. After the stirring is completed, the surface scum is removed, and sampling is performed for analysis. The temperature is raised to 765℃ at a rate of 0.5℃ / min, and aluminum-iron alloy, aluminum-boron alloy, aluminum-yttrium alloy, and rare earth alloy are added. The mixture is stirred at a speed of 300r / min for 45min to obtain a mixed alloy melt A, in which the boron content of the mixed alloy melt A is ≤0.001%. Then, an aluminum-zirconium alloy is added, and the speed is adjusted to 200r / min. The stirring time is 45min. After adding the degassing agent, the mixture is allowed to stand for 10min. After removing the scum, a slag remover is added, and the mixture is stirred at 250r / min for 30min. The surface scum is removed, and the mixture is allowed to stand for 20min. Sampling is performed for analysis to obtain an aluminum alloy melt. Among them, the iron content in aluminum-iron alloy is 5%, the boron content in aluminum-boron alloy is 3%, the yttrium content in aluminum-yttrium alloy is 5%, the rare earth content in rare earth alloy is 10%, and the zirconium content in aluminum-zirconium alloy is 5%; S2: The aluminum alloy melt is degassed and filtered online by an online degassing and filtering system, 0.2wt% aluminum-niobium-boron refining agent is added online to complete online refining of the aluminum alloy melt, and the aluminum alloy melt after online refining is poured into a wheel crystallizer for continuous casting to obtain a casting billet, and the continuous casting temperature is 730°C; S3: transferring the ingot to the continuous rolling mill for continuous rolling, wherein the rolling mill speed is 460 r / min, the rolling mill current is 590 A, the rolling emulsion temperature is 43° C., the rolling emulsion pressure is 0.24 MPa, the rolling entry temperature is 520° C., the rolling temperature is 350° C., and the rolling exit temperature is 200° C., to obtain an aluminum alloy rod with a temperature of 200° C.; S4: subjecting the aluminum alloy rod to a heating aging treatment in an aging furnace, wherein the aging treatment parameters are an aging time of 6 hours and an aging temperature of 300°C, and after aging cooling to 25°C, a wire drawing machine is used to perform wire drawing deformation at a speed of 12 m / s to obtain an aluminum alloy single wire, and after the obtained aluminum alloy single wire is tested, a secondary aging treatment is performed on the aluminum alloy single wire, wherein the secondary aging treatment parameters are an aging time of 4 hours and an aging temperature of 200°C, to obtain the high conductivity heat-resistant aluminum alloy wire having a diameter of 3.99 mm.

[0029] Comparative Example 1 In this comparative example, no aluminum-niobium-boron refining agent is added during the preparation process, and the remaining steps are consistent with Example 1.

[0030] Comparative Example 2 In this comparative example, no aging treatment is performed on the aluminum alloy rod during the preparation process, and the remaining steps are consistent with those in Example 1.

[0031] The conductivity, high temperature resistance and tensile strength of the embodiments and comparative examples were tested. The conductivity test was based on the standard GB / T 30551-2014, and the high temperature test was based on IEC 62004:2007. During the high temperature test, the sample was kept at 230°C for 12 hours to test its strength residual rate. The tensile strength test was based on IEC 62004:2007. The experimental results are summarized in the following table.

[0032] The aluminum alloy wire prepared by the present invention has a conductivity of 61.5% IACS and has better high temperature resistance and mechanical strength.

[0033] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a high conductivity heat-resistant aluminum alloy wire, characterized in that: The specific process of the method for preparing the high conductivity heat-resistant aluminum alloy wire is as follows: S1: The aluminum ingot is completely melted at 670-710°C, a slag remover is added, and the mixture is stirred at a speed of 150-250 r / min for 20-30 min. After the stirring is completed, the surface scum is removed, and a sample is taken for analysis. The temperature is raised to 755-765°C at a rate of 0.2-0.5°C / min, and aluminum-iron alloy, aluminum-boron alloy, aluminum-yttrium alloy, and rare earth alloy are added. The mixture is stirred at a speed of 200-300 r / min for 30-45 min to obtain a mixed alloy melt A. The aluminum-zirconium alloy is then added, and the speed is adjusted to 100-200 r / min. The stirring time is 30-45 min. After adding the degassing agent, the mixture is allowed to stand for 5-10 min. After removing the scum, a slag remover is added, and the mixture is stirred at 150-250 r / min for 20-30 min. The surface scum is removed, and the mixture is allowed to stand for 20 min. The mixture is sampled for analysis to obtain an aluminum alloy melt. S2: The aluminum alloy melt is degassed and filtered online by an online degassing and filtering system, and an aluminum-niobium-boron refining agent is added online to complete the online refining of the aluminum alloy melt. The aluminum alloy melt after online refining is poured into a wheel-type crystallizer for continuous casting to obtain a casting billet. The continuous casting temperature is 720-730°C. S3: transferring the ingot to a continuous rolling mill for continuous rolling, wherein the rolling temperature is 500-520°C, the rolling temperature is 300-350°C, and the exit temperature is 170-200°C, to obtain an aluminum alloy rod; S4: subjecting the aluminum alloy rod to a heating and aging treatment in an aging furnace, cooling the aluminum alloy rod to a temperature of 20-25° C., and then subjecting the aluminum alloy rod to wire drawing deformation at a speed of 12 m / s using a wire drawing machine to obtain an aluminum alloy single wire. After testing the obtained aluminum alloy single wire, the aluminum alloy single wire is subjected to a secondary aging treatment to obtain the high conductivity heat-resistant aluminum alloy wire.

2. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: The aluminum ingot in S1 is an aluminum ingot with a grade of Al99.

85.

3. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: In the S1, the iron content of the aluminum-iron alloy is 5%, the boron content of the aluminum-boron alloy is 3%, the yttrium content of the aluminum-yttrium alloy is 5%, the rare earth content of the rare earth alloy is 10%, and the zirconium content of the aluminum-zirconium alloy is 5%.

4. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: The boron content in the mixed alloy melt A in S1 is ≤0.001%.

5. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: The amount of aluminum niobium boron refining agent added to the S2 is 0.15-0.2wt%.

6. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: The rolling mill speed of the continuous rolling in S3 is 450-460 r / min, the rolling mill current is 560-590 A, the rolling emulsion temperature is 35-43° C., and the rolling emulsion pressure is 0.2-0.24 MPa.

7. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: The temperature of the heat-resistant aluminum alloy rod obtained in S3 is 150-200°C.

8. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: The aging treatment parameters of the S4 aluminum alloy rod material are aging time 3-6h and aging temperature 230-300°C.

9. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: The parameters of the secondary aging treatment of the aluminum alloy in S4 are as follows: an aging time of 3 to 4 hours and an aging temperature of 175 to 200°C.

10. The method for preparing a high conductivity heat-resistant aluminum alloy wire according to claim 1, characterized in that: The diameter of the high-conductivity heat-resistant aluminum alloy wire obtained in S4 is 3.99 mm.

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