High-strength and high-toughness aluminum alloy single wire and preparation method and application thereof

Abstract

The invention provides a high-strength and high-toughness aluminum alloy single wire as well as a preparation method and application thereof, and the high-strength and high-toughness aluminum alloy single wire comprises the following components in percentage by mass: 0.40 to 0.70 weight percent of Si, 0.50 to 0.90 weight percent of Mg, 0.10 to 0.20 weight percent of Fe, 0.05 to 0.20 weight percent of Ni, 0.005 to 0.01 weight percent of Cu and Blt, 0.03 wt%, Mn + Ti + V + Cr < lt >; 0.02 wt%, and the balance being Al. According to the aluminum alloy single wire, the tensile strength and the elongation of the single wire are effectively improved while the high conductivity 52.5% IACS is ensured, the aluminum alloy single wire has high strength and toughness, the tensile strength reaches 363 MPa or above, the elongation reaches 4.5% or above, and the aluminum alloy single wire is used for an overhead conductor aluminum alloy core, the tension-weight ratio of a conductor is effectively improved, and the power transmission loss and the production cost are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of power transmission, and relates to an aluminum alloy core wire for overhead conductors, and in particular to a high-strength and toughness aluminum alloy single wire and a preparation method and application thereof. Background Art

[0002] In modern power transmission systems, overhead conductors are one of the most commonly used transmission methods, especially in long-distance high-voltage transmission lines. Traditional overhead conductors use steel-core aluminum stranded wires, which are composed of a steel core and an outer layer of hard aluminum. Since the strength of hard aluminum is not high, the steel-core aluminum stranded wire is reinforced by the steel core to withstand greater tension. In order to obtain lower line losses and further improve the tension-to-weight ratio of the conductor on high-voltage transmission lines, aluminum alloy core aluminum stranded wires are gradually replaced by steel-core aluminum stranded wires, that is, aluminum alloy cores are used to replace traditional steel cores, which reduces the magnetic loss of the conductor and reduces the line resistance. However, compared with traditional steel cores, the manufacturing cost of aluminum alloy cores has increased to a certain extent, and their mechanical properties have decreased to a certain extent. Therefore, further reducing the manufacturing cost of aluminum alloy core aluminum stranded wires and improving the mechanical properties of aluminum alloy cores have become urgent issues to be solved.

[0003] At present, the industry's research on improving the performance of aluminum alloy core single wire mainly focuses on chemical composition formula, structure and process.

[0004] CN216487353U discloses a reinforced AL5 aluminum alloy core aluminum stranded wire, which uses AL5 aluminum alloy wire and fills the gaps with aramid fiber bundles when twisting into an aluminum alloy core, thereby improving the tension of the core. However, the aramid fiber bundles used in this method are expensive and have no conductive properties. In addition, the gaps in the aluminum alloy core are limited, and the filled aramid fiber bundles are mechanically bonded to the alloy matrix, which has limited effect on improving the overall tension.

[0005] CN111069311A discloses a method for preparing a high-strength and high-conductivity aluminum alloy wire. The method adopts a multi-stage aging heat treatment method to promote the precipitation of nano second phase terms. The strength of the prepared aluminum alloy wire is 341MPa, the conductivity is 54.73%IACS, and the tensile force is not much improved compared with the 315MPa required by the national standard GB / T 23308-2009, and cannot achieve the effect of promoting aluminum alloy core aluminum stranded wire.

[0006] CN111270112A discloses a high-strength and high-conductivity aluminum alloy for overhead wires and a preparation method thereof, which improves the preparation process of the aluminum alloy by first performing an aging treatment and then drawing it into an aluminum alloy monofilament, thereby increasing the tensile strength of the aluminum alloy to above 325 MPa and achieving a conductivity of 56.5% IACS, but the improvement in the tensile strength is not significant.

[0007] CN118880124A discloses a high-strength and high-conductivity aluminum alloy single wire and its production process. By integrating titanium, rare earth elements and other elements into the alloy components to optimize the melt structure and optimize the preparation process, the tensile strength of the aluminum alloy single wire is above 315MPa and the conductivity is above 54.8%IACS. The addition of more titanium, rare earth elements and other components to the aluminum alloy single wire components is not conducive to aluminum alloy cost control, and the tensile strength is still not significantly improved.

[0008] Generally, the strength and conductivity of aluminum alloys are mutually exclusive. Resistivity originates from crystal defects such as solutes, dislocations and vacancies. Therefore, an increase in strength often leads to a decrease in the conductivity of aluminum alloys. Although the aluminum alloy wires of the above-mentioned prior art maintain a relatively high conductivity, their tensile strength has never been significantly improved. Therefore, further improving the strength of aluminum alloy single wires while maintaining a relatively high conductivity has become an urgent problem to be solved. Summary of the invention

[0009] The purpose of the present invention is to provide a high-strength and toughness aluminum alloy single wire and a preparation method and application thereof. The aluminum alloy single wire has high conductivity, while significantly improving the strength and elongation of the aluminum alloy single wire, reducing the cross-sectional proportion of the aluminum alloy core and transmission loss of the aluminum alloy single wire, and reducing the cost of overhead wires.

[0010] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a high-strength and toughness aluminum alloy single wire, wherein the components of the high-strength and toughness aluminum alloy single wire, calculated by mass percentage, include: Si 0.40-0.70wt%, Mg 0.50-0.90wt%, Fe 0.10-0.20wt%, Ni0.05-0.20wt%, Cu 0.005-0.01wt%, B<0.03wt%, Mn+Ti+V+Cr<0.02wt%, and the balance is Al.

[0012] The high-strength and toughness aluminum alloy single wire provided by the present invention is based on an Al-Si-Mg-based aluminum alloy, and the contents of Si, Mg and Fe are regulated and a trace amount of Ni element is added. Ni forms a solid solution strengthening effect in the aluminum matrix, reduces the precipitation of FeSi harmful phases formed by Fe and Si, and significantly enhances the thermal stability of the matrix, thereby significantly enhancing the strength of the aluminum alloy single wire. While maintaining high electrical conductivity, it has high tensile strength and high elongation, does not require the use of precious metals such as zinc and titanium and scarce elements such as scandium, rhenium, and rare earth elements, is easy to prepare, and effectively controls costs.

[0013] In the present invention, the "high strength and toughness" refers to ensuring that the electrical conductivity is greater than 52.5% IACS, the tensile strength is greater than or equal to 360 MPa, and the elongation is greater than or equal to 3.5%.

[0014] In the present invention, the Si content of the high-strength and toughness aluminum alloy single wire is 0.40-0.70wt%, for example, it can be 0.40wt%, 0.42wt%, 0.45wt%, 0.48wt%, 0.50wt%, 0.52wt%, 0.55wt%, 0.57wt%, 0.58wt%, 0.59wt%, 0.60wt%, 0.61wt%, 0.62wt%, 0.63wt%, 0.65wt%, 0.68wt% or 0.70wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0015] In the present invention, the Mg content of the high-strength and toughness aluminum alloy single wire is 0.50-0.90wt%, for example, it can be 0.50wt%, 0.52wt%, 0.55wt%, 0.58wt%, 0.60wt%, 0.62wt%, 0.65wt%, 0.67wt%, 0.68wt%, 0.69wt%, 0.70wt%, 0.71wt%, 0.72wt%, 0.73wt%, 0.75wt%, 0.78wt%, 0.80wt%, 0.82wt%, 0.85wt%, 0.88wt% or 0.90wt%, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0016] In the present invention, the Fe content of the high-strength and toughness aluminum alloy single wire is 0.10-0.20wt%, for example, it can be 0.10wt%, 0.11wt%, 0.12wt%, 0.13wt%, 0.14wt%, 0.15wt%, 0.16wt%, 0.17wt%, 0.18wt%, 0.19wt% or 0.20wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] In the present invention, the Ni content of the high-strength and toughness aluminum alloy single wire is 0.05-0.20wt%, for example, it can be 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.10wt%, 0.11wt%, 0.12wt%, 0.13wt%, 0.14wt%, 0.15wt%, 0.16wt%, 0.17wt%, 0.18wt%, 0.19wt% or 0.20wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In the present invention, the Cu content of the high-strength and toughness aluminum alloy single wire is 0.005-0.01wt%, for example, it can be 0.005wt%, 0.006wt%, 0.007wt%, 0.008wt%, 0.009wt% or 0.010wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] In the present invention, the B content of the high-strength and toughness aluminum alloy single wire is <0.03wt%, for example, it can be 0.001wt%, 0.005wt%, 0.010wt%, 0.015wt%, 0.020wt%, 0.025wt% or 0.030wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In the present invention, the total content of Mn+Ti+V+Cr in the high-strength and toughness aluminum alloy single wire is <0.02wt%, for example, it can be 0.001wt%, 0.005wt%, 0.010wt%, 0.015wt% or 0.019wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the components of the high-strength and toughness aluminum alloy single wire are, by mass percentage, Si 0.60-0.70wt%, Mg 0.65-0.85wt%, Fe 0.10-0.15wt%, Ni 0.010-0.20wt%, Cu 0.005-0.01wt%, B≤0.01wt%, Mn+Ti+V+Cr≤0.01wt%, and the balance is Al.

[0022] In a second aspect, the present invention provides a method for preparing the high-strength and toughness aluminum alloy single wire according to the first aspect, the preparation method comprising the following steps:

[0023] (1) cold rolling the aluminum alloy rod having the target composition obtained by continuous casting and rolling, and then performing a deformation heat treatment to obtain a deformed aluminum alloy rod;

[0024] (2) Drawing the deformed aluminum alloy rod to obtain an aluminum alloy wire, and subjecting the aluminum alloy wire to aging treatment to obtain the high-strength and toughness aluminum alloy single wire.

[0025] The preparation method provided by the present invention performs rolling pre-deformation and deformation heat treatment processes on the aluminum alloy rod before preparing the wire rod from the aluminum alloy rod, thereby improving the dislocation density of the aluminum alloy rod, thereby effectively promoting the dispersion and precipitation of the second phase. At the same time, the heat treatment is controlled to adopt a lower temperature and a shorter time, which effectively increases the interaction between the second phase and the dislocation. After the rolling deformation and deformation heat treatment, drawing and aging treatment are performed. During the drawing and aging treatment, the solid solution atoms of the matrix are further precipitated, thereby achieving simultaneous improvement of the conductivity, strength and toughness.

[0026] Preferably, the number of cold rolling passes in step (1) is 2-8 passes, for example, it can be 2 passes, 3 passes, 4 passes, 5 passes, 6 passes, 7 passes or 8 passes.

[0027] Preferably, the single-pass deformation of the cold rolling in step (1) is 15-35%, for example, it can be 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32% or 35%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the temperature of the deformation heat treatment in step (1) is 145-195°C, for example, it can be 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C or 195°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] Preferably, the holding time of the deformation heat treatment in step (1) is 0.5-10h, for example, it can be 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h or 10h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] Preferably, the method for preparing the aluminum alloy rod in step (1) comprises:

[0031] (a) adding component elements to aluminum liquid for refining to obtain an alloy melt;

[0032] (b) The alloy melt is filtered and then cast to obtain an alloy ingot, the alloy ingot is subjected to a solid solution treatment, and then continuously rolled after the solid solution treatment to obtain the aluminum alloy rod.

[0033] Preferably, the temperature of the alloy melt is controlled to be 720-750°C, for example, it can be 720°C, 725°C, 730°C, 735°C, 740°C, 745°C or 750°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] Preferably, the casting temperature is 690-710°C, for example, 690°C, 695°C, 700°C, 705°C or 710°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] Preferably, the casting speed is 7-10 m / min, for example, 7 m / min, 7.5 m / min, 8 m / min, 8.5 m / min, 9 m / min, 9.5 m / min or 10 m / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the temperature of the solution treatment is 500-540°C, for example, it can be 500°C, 505°C, 510°C, 515°C, 520°C, 525°C, 530°C, 535°C or 540°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Preferably, the coiling temperature of the continuous rolling is 10-120°C, for example, it can be 10°C, 30°C, 50°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] Preferably, the diameter of the aluminum alloy rod in step (1) is 11-20 mm, for example, 11 mm, 13 mm, 15 mm, 18 mm or 20 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Preferably, the diameter of the deformed aluminum alloy rod in step (1) is 9.5-18 mm, for example, 9.5 mm, 10 mm, 12 mm, 15 mm or 18 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] Preferably, the deformation amount of a single drawing pass in step (2) is 15-35%, for example, it can be 15%, 16%, 18%, 20%, 22%, 24%, 25%, 28%, 30%, 32% or 35%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0041] Preferably, the drawing speed in step (2) is 5-14 m / s, for example, 5 m / s, 8 m / s, 10 m / s, 11 m / s, 12 m / s, 13 m / s or 14 m / s, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] Preferably, the diameter of the aluminum alloy wire in step (2) is 2.3-4.2 mm, for example, it can be 2.3 mm, 2.5 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4.0 mm or 4.2 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0043] Preferably, the temperature of the aging treatment in step (2) is 130-180°C, for example, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0044] Preferably, the holding time of the aging treatment in step (2) is 0.5-8h, for example, it can be 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h or 8h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0045] In a third aspect, the present invention provides an overhead conductor, comprising: an aluminum alloy core and a covering layer, wherein the aluminum alloy core is formed by twisting the high-strength and toughness aluminum alloy single wires described in the first aspect.

[0046] In the overhead conductor provided by the present invention, the aluminum alloy single wires provided by the first aspect are twisted to form an aluminum alloy core. The performance of the aluminum alloy single wire is greatly improved compared with the tensile strength ≥315MPa, conductivity ≥52.5%IACS, and elongation ≥3.0% required by GB / T 23308-2009, which can greatly reduce the cross-sectional area of ​​the aluminum alloy core, reduce transmission losses, and thus effectively reduce the cost of the aluminum alloy core. Taking the aluminum alloy core aluminum stranded wire product JL / LHA1210 / 220 as an example, the cross-sectional area of ​​the aluminum alloy core in the aluminum alloy core aluminum stranded wire can be reduced to 170mm 2 The following can reduce transmission loss by more than 2% and the cost of aluminum alloy core by more than 23%.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The aluminum alloy single wire provided by the present invention adopts Ni element addition, reasonably adjusts the component ratio, and adds deformation and heat treatment steps in the preparation process. While ensuring a high conductivity of 52.5% IACS, the tensile strength and elongation of the single wire are effectively improved. The wire has high toughness, a tensile strength of more than 363 MPa, and an elongation of more than 4.5%. It is used for the aluminum alloy core of overhead conductors, effectively improving the conductor pull-to-weight ratio, and reducing transmission losses and production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1This is a process flow chart of the method for preparing a high-strength and tough aluminum alloy single wire provided in Example 1. DETAILED DESCRIPTION

[0050] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0051] Example 1

[0052] The present embodiment provides a high-strength and toughness aluminum alloy single wire, and the components of the high-strength and toughness aluminum alloy single wire are, in terms of mass percentage, Si 0.6wt%, Mg 0.7wt%, Cu 0.005wt%, Fe 0.14wt%, Ni0.05wt%, B0.005wt%, Mn+Ti+V+Cr 0.018wt%, and the balance is Al.

[0053] like Figure 1 As shown, the method for preparing the high-strength and toughness aluminum alloy single wire comprises the following steps:

[0054] (1) placing an aluminum ingot for electrical remelting with a grade of Al99.70 into a melting furnace for melting, and charging a commercial high-efficiency refining agent of 2wt‰ of the weight of the aluminum liquid into the holding furnace in batches for refining. After the refining is completed, the scum on the surface of the aluminum liquid is scraped off, and the aluminum liquid after scraping is allowed to stand for 30 minutes. Electrolytic nickel with a grade of 9990, aluminum-12wt% silicon intermediate alloy ingot and magnesium ingot with a grade of 9990 are added in sequence, and stirred for 5-10 minutes. The aluminum liquid temperature is maintained at 750°C, and after refining with a high-efficiency refining agent of 2wt‰ of the weight of the aluminum liquid, the slag is scraped off and allowed to stand, and then sampling and analysis are performed. The analysis results of the components of the alloy liquid are as shown in the components of the high-strength and toughness aluminum alloy single wire, and an aluminum alloy liquid is obtained;

[0055] (2) The aluminum alloy liquid is filtered through a box-type two-stage 20ppi / 40ppi alumina ceramic filter plate, and then continuously cast through a wheel crystallization system. The cross-sectional area of ​​the ingot is 2500mm 2 , the casting temperature is 690°C, the casting speed is 10m / min, and a casting billet is obtained;

[0056] (3) The ingot is introduced into the medium frequency heating device through the introduction device, and the ingot is heated to 525°C to complete the online solid solution, and then enters the continuous rolling unit for continuous rolling. After rolling, an aluminum alloy rod with a diameter of 15 mm is obtained, which is cooled by online cooling water and automatically coiled. The surface temperature of the aluminum alloy rod after coiling is controlled at 80°C;

[0057] (4) The aluminum alloy rod then enters the cold rolling device and undergoes 4 passes, with a deformation of 20% per pass, to be rolled into a 9.5 mm aluminum alloy rod, and then enters a roller furnace with a furnace temperature of 155°C for 3 hours;

[0058] (5) Drawing the heat-treated aluminum alloy rod into a wire, with a drawing deformation of 20% per drawing pass, a drawing speed of 12 m / s, and a finished wire diameter of 4.20 mm;

[0059] (6) performing aging treatment on the finished wire rod, wherein the aging treatment temperature is 155° C. and the aging treatment time is 8 h, thereby obtaining the high-strength and toughness aluminum alloy single wire.

[0060] Example 2

[0061] The present embodiment provides a high-strength and toughness aluminum alloy single wire, and the components of the high-strength and toughness aluminum alloy single wire are, in terms of mass percentage, Si 0.5wt%, Mg 0.8wt%, Cu 0.007wt%, Fe 0.11wt%, Ni 0.10wt%, B 0.01wt%, Mn+Ti+V+Cr 0.008wt%, and the balance is Al.

[0062] The method for preparing the high-strength and toughness aluminum alloy single wire comprises the following steps:

[0063] (1) placing an aluminum ingot for electrical remelting with a grade of Al99.70 into a melting furnace for melting, and charging a commercial high-efficiency refining agent at a rate of 2 wt‰ of the weight of the aluminum liquid into the holding furnace in batches for refining. After the refining is completed, the scum on the surface of the aluminum liquid is scraped off, and the aluminum liquid after scraping off is allowed to stand for 30 minutes. Electrolytic nickel with a grade of 9990, an aluminum-12 wt% silicon intermediate alloy ingot, and a magnesium ingot with a grade of 9990 are added in sequence, and stirred for 5-10 minutes. The aluminum liquid is kept at a temperature of 730°C, and after refining with a high-efficiency refining agent at a rate of 2 wt‰ of the weight of the aluminum liquid, the slag is scraped off and allowed to stand, and then sampling and analysis are performed. The analysis results of the components of the alloy liquid are as shown in the components of the high-strength and toughness aluminum alloy single wire, and an aluminum alloy liquid is obtained;

[0064] (2) The aluminum alloy liquid is filtered through a box-type two-stage 20ppi / 40ppi alumina ceramic filter plate, and then continuously cast through a wheel crystallization system. The cross-sectional area of ​​the ingot is 3200mm 2 , the casting temperature is 710°C, the casting speed is 7m / min, and a casting billet is obtained;

[0065] (3) The ingot is introduced into the medium frequency heating device through the introduction device, and the ingot is heated to 515°C to complete the online solution treatment, and then enters the continuous rolling unit for continuous rolling. After rolling, an aluminum alloy rod with a diameter of 11 mm is obtained, which is cooled by online cooling water and automatically coiled. The surface temperature of the aluminum alloy rod after coiling is controlled at 70°C;

[0066] (4) The aluminum alloy rod then enters the cold rolling device, undergoes two passes, and the deformation of each pass is 20%, and is rolled into a 9.5 mm aluminum alloy rod. It then enters a roller furnace with a furnace temperature of 195°C and is kept warm for 0.5 h.

[0067] (5) Drawing the heat-treated aluminum alloy rod into a wire, with a drawing deformation of 20% per drawing pass, a drawing speed of 12 m / s, and a finished wire diameter of 3.67 mm;

[0068] (6) performing aging treatment on the finished wire rod, wherein the aging treatment temperature is 175° C. and the aging treatment time is 0.5 h, thereby obtaining the high-strength and toughness aluminum alloy single wire.

[0069] Example 3

[0070] The present embodiment provides a high-strength and toughness aluminum alloy single wire, and the components of the high-strength and toughness aluminum alloy single wire are, in terms of mass percentage, Si 0.7wt%, Mg 0.8wt%, Cu 0.008wt%, Fe 0.18wt%, Ni 0.20wt%, B 0.02wt%, Mn+Ti+V+Cr 0.012wt%, and the balance is Al.

[0071] The method for preparing the high-strength and toughness aluminum alloy single wire comprises the following steps:

[0072] (1) placing an aluminum ingot for electrical remelting with a grade of Al99.70 into a melting furnace for melting, and charging a commercial high-efficiency refining agent at a rate of 2 wt‰ of the weight of the aluminum liquid into the holding furnace in batches for refining. After the refining is completed, the scum on the surface of the aluminum liquid is scraped off, and the aluminum liquid after scraping off is allowed to stand for 30 minutes. Electrolytic nickel with a grade of 9990, an aluminum-12 wt% silicon intermediate alloy ingot, and a magnesium ingot with a grade of 9990 are added in sequence. After stirring for 5-10 minutes, the aluminum liquid temperature is maintained at 740° C., and after refining with a high-efficiency refining agent at a rate of 2 wt‰ of the weight of the aluminum liquid, the slag is scraped off and allowed to stand, and then sampling and analysis are performed. The analysis results of the components of the alloy liquid are as shown in the components of the high-strength and toughness aluminum alloy single wire, and an aluminum alloy liquid is obtained;

[0073] (2) The aluminum alloy liquid is filtered through a box-type two-stage 20ppi / 40ppi alumina ceramic filter plate, and then continuously cast through a wheel crystallization system. The cross-sectional area of ​​the ingot is 2500mm 2 , the casting temperature is 700°C, the casting speed is 8m / min, and a casting billet is obtained;

[0074] (3) The ingot is introduced into the medium frequency heating device through the introduction device, and the ingot is heated to 515°C to complete the online solution treatment, and then enters the continuous rolling unit for continuous rolling. After rolling, an aluminum alloy rod with a diameter of 20 mm is obtained, which is cooled by online cooling water and automatically coiled. The surface temperature of the aluminum alloy rod after coiling is controlled at 70°C;

[0075] (4) The aluminum alloy rod then enters the cold rolling device, undergoes 8 passes, and the deformation of each pass is 20%, and is rolled into a 9.5 mm aluminum alloy rod. It then enters the roller furnace, the furnace temperature is 185°C, and is kept warm for 10 hours;

[0076] (5) Drawing the heat-treated aluminum alloy rod into a wire, with a drawing deformation of 20% per drawing pass, a drawing speed of 12 m / s, and a finished wire diameter of 2.30 mm;

[0077] (6) performing aging treatment on the finished wire rod, wherein the aging treatment temperature is 135° C. and the aging treatment time is 4 h, thereby obtaining the high-strength and toughness aluminum alloy single wire.

[0078] Example 4

[0079] The present embodiment provides a high-strength and toughness aluminum alloy single wire, and the components of the high-strength and toughness aluminum alloy single wire are, in terms of mass percentage, Si 0.4wt%, Mg 0.5wt%, Cu 0.009wt%, Fe 0.10wt%, Ni 0.08wt%, B 0.005wt%, Mn+Ti+V+Cr 0.005wt%, and the balance is Al.

[0080] The method for preparing the high-strength and toughness aluminum alloy single wire comprises the following steps:

[0081] (1) placing an aluminum ingot for electrical remelting with a grade of Al99.70 into a melting furnace for melting, and charging a commercial high-efficiency refining agent at a rate of 2 wt‰ of the weight of the aluminum liquid into the holding furnace in batches for refining. After the refining is completed, the scum on the surface of the aluminum liquid is scraped off, and the aluminum liquid after scraping off is allowed to stand for 30 minutes. Electrolytic nickel with a grade of 9990, an aluminum-12 wt% silicon intermediate alloy ingot, and a magnesium ingot with a grade of 9990 are added in sequence, and stirred for 5-10 minutes. The aluminum liquid is kept at a temperature of 720°C, and after refining with a high-efficiency refining agent at a rate of 2 wt‰ of the weight of the aluminum liquid, the slag is scraped off and allowed to stand, and then sampling and analysis are performed. The analysis results of the components of the alloy liquid are as shown in the components of the high-strength and toughness aluminum alloy single wire, and an aluminum alloy liquid is obtained;

[0082] (2) The aluminum alloy liquid is filtered through a box-type two-stage 20ppi / 40ppi alumina ceramic filter plate, and then continuously cast through a wheel crystallization system. The cross-sectional area of ​​the ingot is 2500mm 2 , the casting temperature is 700°C, the casting speed is 10m / min, and a casting billet is obtained;

[0083] (3) The ingot is introduced into the medium frequency heating device through the introduction device, and the ingot is heated to 500°C to complete the online solid solution, and then enters the continuous rolling unit for continuous rolling. After rolling, an aluminum alloy rod with a diameter of 15 mm is obtained, which is cooled by online cooling water and automatically coiled. The surface temperature of the aluminum alloy rod after coiling is controlled at 100°C;

[0084] (4) The aluminum alloy rod then enters the cold rolling device and undergoes 4 passes with a deformation of 15% per pass to be rolled into a 9.5 mm aluminum alloy rod. It then enters a roller furnace with a furnace temperature of 145°C for 3 hours.

[0085] (5) Drawing the heat-treated aluminum alloy rod into a wire, with a drawing deformation of 20% per drawing pass, a drawing speed of 12 m / s, and a finished wire diameter of 4.20 mm;

[0086] (6) performing aging treatment on the finished wire rod, wherein the aging treatment temperature is 130° C. and the aging treatment time is 8 h, thereby obtaining the high-strength and toughness aluminum alloy single wire.

[0087] Example 5

[0088] The present embodiment provides a high-strength and toughness aluminum alloy single wire, and the components of the high-strength and toughness aluminum alloy single wire are, in terms of mass percentage, Si 0.65wt%, Mg 0.9wt%, Cu 0.01wt%, Fe 0.20wt%, Ni 0.12wt%, B 0.008wt%, Mn+Ti+V+Cr 0.001wt%, and the balance is Al.

[0089] The method for preparing the high-strength and toughness aluminum alloy single wire comprises the following steps:

[0090] (1) placing an aluminum ingot for electrical remelting with a grade of Al99.70 into a melting furnace for melting, and charging a commercial high-efficiency refining agent of 2wt‰ of the weight of the aluminum liquid into the holding furnace in batches for refining. After the refining is completed, the scum on the surface of the aluminum liquid is scraped off, and the aluminum liquid after scraping is allowed to stand for 30 minutes. Electrolytic nickel with a grade of 9990, aluminum-12wt% silicon intermediate alloy ingot and magnesium ingot with a grade of 9990 are added in sequence, and stirred for 5-10 minutes. The aluminum liquid temperature is maintained at 740°C, and after refining with a high-efficiency refining agent of 2wt‰ of the weight of the aluminum liquid, the slag is scraped off and allowed to stand, and then sampling and analysis are performed. The analysis results of the components of the alloy liquid are as shown in the components of the high-strength and toughness aluminum alloy single wire, and an aluminum alloy liquid is obtained;

[0091] (2) The aluminum alloy liquid is filtered through a box-type two-stage 20ppi / 40ppi alumina ceramic filter plate, and then continuously cast through a wheel crystallization system. The cross-sectional area of ​​the ingot is 2500mm 2, the casting temperature is 710°C, the casting speed is 10m / min, and a casting billet is obtained;

[0092] (3) The ingot is introduced into the medium frequency heating device through the introduction device, and the ingot is heated to 540°C to complete the online solid solution, and then enters the continuous rolling unit for continuous rolling. After rolling, an aluminum alloy rod with a diameter of 15 mm is obtained, which is cooled by online cooling water and automatically coiled. The surface temperature of the aluminum alloy rod after coiling is controlled at 115°C;

[0093] (4) The aluminum alloy rod then enters the cold rolling device and undergoes 4 passes, with a deformation of 35% per pass, to be rolled into a 9.5 mm aluminum alloy rod, and then enters a roller furnace with a furnace temperature of 170°C for 3 hours;

[0094] (5) Drawing the heat-treated aluminum alloy rod into a wire, with a drawing deformation of 20% per drawing pass, a drawing speed of 12 m / s, and a finished wire diameter of 4.20 mm;

[0095] (6) performing aging treatment on the finished wire rod, wherein the aging treatment temperature is 180° C. and the aging treatment time is 4 h, thereby obtaining the high-strength and toughness aluminum alloy single wire.

[0096] Comparative Example 1

[0097] This comparative example provides an aluminum alloy single wire.

[0098] The components of the aluminum alloy single wire are, by mass percentage, Si 0.6wt%, Mg 0.7wt%, Cu 0.005wt%, Fe 0.14wt%, B 0.005wt%, Mn+Ti+V+Cr 0.018wt%, and the balance is Al.

[0099] Compared with Example 1, the method for preparing the aluminum alloy single wire is the same as Example 1 except that no electrolytic nickel is added in step (1).

[0100] Comparative Example 2

[0101] This comparative example provides an aluminum alloy single wire.

[0102] The components of the aluminum alloy single wire are, by mass percentage, Si 0.6wt%, Mg 0.7wt%, Cu 0.005wt%, Fe 0.14wt%, Ni 0.3wt%, B 0.005wt%, Mn+Ti+V+Cr 0.018wt%, and the balance is Al.

[0103] The preparation method of the aluminum alloy single wire is the same as that in Example 1.

[0104] Performance Characterization

[0105] The tensile strength, electrical conductivity and elongation of the aluminum alloy single wires provided in the embodiments and comparative examples were tested, and the results are listed in Table 1.

[0106] The tensile strength test is carried out in accordance with GB / T 4909.3, the conductivity test is carried out in accordance with GB / T 3048.2, and the elongation test is carried out in accordance with GB / T 4909.3.

[0107] Table 1

[0108]

[0109]

[0110] It can be seen from Table 1 that, through the content of the present invention, the aluminum alloy conductor single wire can greatly increase the tensile strength of the single wire to more than 360MPa and the elongation to more than 3.5% on the basis of ensuring 52.5% IACS, thereby achieving the effect of increasing the toughness of the single wire, increasing the span of the overhead transmission line, improving the safety margin of the transmission line, and reducing the total cost of the line. Compared with Example 1, in Comparative Examples 1 and 2, when the Ni content is too high or too low, the tensile strength of the single wire is reduced.

[0111] In summary, the aluminum alloy single wire provided by the present invention adopts Ni element addition, reasonably adjusts the component ratio, and adds deformation and heat treatment steps in the preparation process. While ensuring a high conductivity of 52.5% IACS, the tensile strength and elongation of the single wire are effectively improved. It has high strength and toughness, a tensile strength of more than 363MPa, and an elongation of more than 4.5%. It is used for the aluminum alloy core of overhead conductors, effectively improving the conductor pull-to-weight ratio and reducing transmission losses and production costs.

[0112] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A high-strength and tough aluminum alloy single wire, characterized in that: The components of the high-strength and toughness aluminum alloy single wire include, by mass percentage, Si 0.40-0.70wt%, Mg 0.50-0.90wt%, Fe 0.10-0.20wt%, Ni 0.05-0.20wt%, Cu 0.005-0.01wt%, B<0.03wt%, Mn+Ti+V+Cr<0.02wt%, and the balance is Al.

2. The high-strength and toughness aluminum alloy single wire according to claim 1, characterized in that: The components of the high-strength and toughness aluminum alloy single wire are, by mass percentage, Si 0.60-0.70wt%, Mg 0.65-0.85wt%, Fe 0.10-0.15wt%, Ni0.010-0.20wt%, Cu 0.005-0.01wt%, B≤0.01wt%, Mn+Ti+V+Cr≤0.01wt%, and the balance is Al.

3. A method for preparing a high-strength and tough aluminum alloy single wire as claimed in claim 1 or 2, characterized in that: The preparation method comprises the following steps: (1) cold rolling the aluminum alloy rod having the target composition obtained by continuous casting and rolling, and then performing a deformation heat treatment to obtain a deformed aluminum alloy rod; (2) Drawing the deformed aluminum alloy rod to obtain an aluminum alloy wire, and subjecting the aluminum alloy wire to aging treatment to obtain the high-strength and toughness aluminum alloy single wire.

4. The preparation method according to claim 3, characterized in that: The number of cold rolling passes in step (1) is 2-8; Preferably, the deformation amount of a single cold rolling pass in step (1) is 15-35%.

5. The preparation method according to claim 3 or 4, characterized in that: The temperature of the deformation heat treatment in step (1) is 145-195°C; Preferably, the holding time of the deformation heat treatment in step (1) is 0.5-10h.

6. The preparation method according to any one of claims 3 to 5, characterized in that: The method for preparing the aluminum alloy rod in step (1) comprises: (a) adding component elements to aluminum liquid for refining to obtain an alloy melt; (b) the alloy melt is filtered and then cast to obtain an alloy ingot, the alloy ingot is subjected to a solution treatment, and then continuously rolled after the solution treatment to obtain the aluminum alloy rod; Preferably, the temperature of the alloy melt is controlled to be 720-750°C; Preferably, the casting temperature is 690-710°C; Preferably, the casting speed is 7-10 m / min; Preferably, the temperature of the solution treatment is 500-540°C; Preferably, the coiling temperature of the continuous rolling is 10-120°C.

7. The preparation method according to any one of claims 3 to 6, characterized in that: The diameter of the aluminum alloy rod in step (1) is 11-20 mm; Preferably, the diameter of the deformed aluminum alloy rod in step (1) is 9.5-18 mm.

8. The preparation method according to any one of claims 3 to 7, characterized in that: The deformation of a single drawing pass in step (2) is 15-35%; Preferably, the drawing speed in step (2) is 5-14 m / s; Preferably, the diameter of the aluminum alloy wire in step (2) is 2.3-4.2 mm.

9. The preparation method according to any one of claims 3 to 8, characterized in that: The temperature of the aging treatment in step (2) is 130-180°C; Preferably, the holding time of the aging treatment in step (2) is 0.5-8h.

10. An overhead conductor, characterized in that: The overhead conductor comprises: an aluminum alloy core and a covering layer, wherein the aluminum alloy core is formed by twisting the high-strength and toughness aluminum alloy single wires as described in claim 1 or 2.

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