Steel-cored aluminum stranded wire for power transmission line

Abstract

The invention relates to the technical field of steel-cored aluminum stranded wires, and provides a steel-cored aluminum stranded wire for a power transmission line, the steel-cored aluminum stranded wire comprises a galvanized steel core and an aluminum wire stranded on the surface of the galvanized steel core, and the preparation process of the galvanized steel core comprises the following steps: deoiling, washing and drying a steel wire, immersing the steel wire in zinc liquid, galvanizing and cooling to obtain a galvanized steel wire; passivating, drying and twisting a galvanized steel wire to obtain a galvanized steel core; a passivation solution used in the passivation process is composed of the following components in percentage by mass: 16%-22% of waterborne acrylic resin, 0.6%-1.2% of an anionic surfactant, 2%-4% of filler, 1%-3% of a silane coupling agent and the balance of water. The filler includes a carrier-loaded metal oxysalt. According to the technical scheme, the problem of insufficient corrosion resistance of the steel-cored aluminum strand in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel-cored aluminum stranded conductor, in particular to a steel-cored aluminum stranded conductor for power transmission line. BACKGROUND

[0002] As the core conductor material of high-voltage power transmission line, the steel-cored aluminum stranded conductor is widely used in various power transmission scenes such as plains, mountains and coastal areas. However, the defect of insufficient corrosion resistance has long restricted the safety and service life of the power transmission line. The steel-cored aluminum stranded conductor is easily corroded in the corrosive medium in the natural environment, such as coastal areas and industrial areas. In the structure of the steel-cored aluminum stranded conductor, the steel core bears the main mechanical tension. In order to improve its corrosion resistance, the industry generally adopts hot galvanizing or electroplating zinc process to coat the surface of the steel core, and then carries out passivation treatment after galvanizing. The passivation treatment forms a dense passivation film on the surface of the galvanized layer, closes the micropores and defects of the galvanized layer, and reduces the direct contact between the galvanized layer and the corrosive medium, thereby further enhancing the corrosion resistance of the galvanized steel core.

[0003] At present, the commonly used passivation agent in the industry mainly includes chromate passivation agent and chromium-free passivation agent. Among them, the chromium-free passivation agent meets the environmental protection requirements, but the passivation film formed by the existing products generally has the problems of insufficient density, poor adhesion, limited salt mist corrosion resistance and the like, and it is difficult to meet the long-term corrosion resistance protection requirements of the steel-cored aluminum stranded conductor in the use environment. Therefore, it is very important to develop a new type of passivation agent which is environmentally friendly and efficient, and can form a passivation film with high density, strong adhesion and excellent corrosion resistance on the surface of the galvanized steel core, so as to improve the corrosion resistance of the galvanized steel core, and further prolong the service life of the steel-cored aluminum stranded conductor and ensure the safety and stability of power transmission. SUMMARY

[0004] The present application provides a steel-cored aluminum stranded conductor for power transmission line, which solves the problem of insufficient corrosion resistance of the steel-cored aluminum stranded conductor in the related art.

[0005] The technical scheme of the present application is as follows: The present application provides a steel-cored aluminum stranded conductor for power transmission line, which includes a galvanized steel core and an aluminum wire stranded on the surface of the galvanized steel core. The preparation process of the galvanized steel core includes the following steps: after the steel wire is degreased, washed and dried, it is immersed in a zinc liquid, cooled after galvanizing, and a galvanized steel wire is obtained. The galvanized steel wire is passivated, dried and stranded to obtain a galvanized steel core. The passivation liquid used in the passivation process is composed of the following components in mass percentage: water-based acrylic resin 16%~22%, anionic surfactant 0.6%~1.2%, filler 2%~4%, silane coupling agent 1%~3%, and the balance is water. The filler includes a carrier loaded metal oxoacid salt. The carrier in the carrier-loaded metal oxyacid salt comprises one of silica and diatomite; The metal oxyacid salt in the carrier-loaded metal oxyacid salt comprises one of tungstate and molybdate.

[0006] As a further technical solution, the carrier-loaded metal oxyacid salt is composed of silica-loaded sodium tungstate and diatomite-loaded sodium molybdate with a mass ratio of 1-3:1.

[0007] The silica-loaded sodium tungstate and diatomite-loaded sodium molybdate are compounded and added into the passivation solution, and the corrosion resistance of the galvanized steel core after passivation is greatly improved; the zinc tungsten oxide precipitate and the molybdate complex are interwoven with each other in the forming process, and a more compact protective film is formed; the pore structures of the silica and the diatomite are different and complement each other, the mesopores of the silica can adsorb smaller corrosion medium ions, and the macropores and mesopores of the diatomite can help accommodate larger molecules or ion groups, thereby increasing the corrosion resistance of the galvanized steel core and improving the corrosion resistance of the steel core aluminum strand.

[0008] As a further technical solution, the preparation method of the carrier-loaded metal oxyacid salt comprises the following steps: S1, the carrier is leached with a nitric acid solution, then washed with water until neutral, dried, ground, and an activated carrier is obtained; S2, the metal oxyacid salt is added into water, and then the activated carrier is added, refluxed, filtered, and dried, to obtain the carrier-loaded metal oxyacid salt.

[0009] As a further technical solution, the molar concentration of the nitric acid solution is 0.15-0.25 mol / L.

[0010] As a further technical solution, the leaching is performed 2-3 times.

[0011] As a further technical solution, in step S1, the drying temperature is 100-120℃, and the time is 6-8h.

[0012] As a further technical solution, when the activated carrier is activated silica, the particle size of the activated silica is 1-2μm; when the activated carrier is activated diatomite, the particle size of the activated diatomite is 3-4μm.

[0013] As a further technical solution, the mass ratio of the metal oxyacid salt to water is 1:8-12.

[0014] As a further technical solution, the mass ratio of the metal oxyacid salt to the activated carrier is 1:3-5.

[0015] As a further technical solution, the refluxing temperature is 100-105℃, and the time is 4-5h.

[0016] As a further technical solution, the reflux reaction process is accompanied by stirring, and the stirring rate is 200-300 r / min.

[0017] As a further technical solution, in step S2, the drying temperature is 80-100 DEG C, and the time is 10-15 h.

[0018] As a further technical solution, the passivation temperature is 40-50 DEG C, and the time is 10-12 min.

[0019] As a further technical solution, the temperature of the zinc liquid is 420-450 DEG C, and the time is 100-120 s.

[0020] As a further technical solution, the cooling includes first-stage cooling, second-stage cooling, and third-stage cooling, and the cooling rates of the first-stage cooling, the second-stage cooling, and the third-stage cooling are different.

[0021] As a further technical solution, the first-stage cooling is cooling to 260-280 DEG C at a cooling rate of 18-20 DEG C / s, and holding for 10-15 min; the second-stage cooling is cooling to 180-200 DEG C at a cooling rate of 6-8 DEG C / s, and holding for 5-8 min; the third-stage cooling is cooling to room temperature at a cooling rate of 3-5 DEG C / s.

[0022] In the preparation process of the galvanized steel core, the cooling rate of the three cooling time periods is regulated during the cooling after galvanizing, so that the tensile strength of the galvanized steel wire can be improved. The first-stage cooling rate is 18-20 DEG C / s, the surface of the galvanized layer is rapidly solidified in this stage, and a fine and uniform grain structure is formed; the second-stage cooling rate is 6-8 DEG C / s, which promotes the solidification and organization transformation of the galvanized layer, further refines the grains, and at the same time, the zinc-iron alloy layer begins to form gradually, and this cooling rate is helpful for the uniform diffusion and reaction of elements in the alloy layer, forming a uniform and dense zinc-iron alloy layer structure; and at this cooling rate, part of the stress in the steel wire matrix is eliminated, and a more ordered dislocation structure is formed, which can better realize uniform plastic deformation under stress and improve the strength of the steel wire matrix; the third-stage cooling rate is 3-5 DEG C / s, which slowly cools to further eliminate internal stress, and is helpful for forming better bonding force between the galvanized layer and the zinc-iron alloy layer and the steel wire matrix, which can effectively transmit stress under stress and make the organization of the steel wire matrix further uniform, thereby improving the tensile strength of the galvanized steel wire, and further improving the tensile strength of the steel core aluminum stranded wire.

[0023] As a further technical solution, the anionic surfactant comprises one of sodium dodecyl benzene sulfonate and calcium dodecyl benzene sulfonate.

[0024] In the passivation solution, the anionic surfactant can reduce the surface tension of the passivation solution, ensure uniform coverage of the passivation solution, and improve the passivation effect; the anionic surfactant is one or more of conventional anionic surfactants, for example, can be sodium dodecyl benzene sulfonate, calcium dodecyl benzene sulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, etc.; preferably, the anionic surfactant is one of sodium dodecyl benzene sulfonate and calcium dodecyl benzene sulfonate.

[0025] As a further technical solution, the silane coupling agent comprises one of silane coupling agent KH-550 and silane coupling agent KH-560.

[0026] In the passivation solution, the silane coupling agent enhances the bonding force between the film layer and the galvanized layer; the silane coupling agent can be one or more of conventional silane coupling agents, for example, can be silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-792, etc.; preferably, the silane coupling agent is one of silane coupling agent KH-550 and silane coupling agent KH-560.

[0027] The working principle and beneficial effects of the present application are as follows: The present application adds the carrier-loaded metal oxoacid salt into the passivation solution to perform passivation treatment on the galvanized steel wire, and the obtained galvanized steel core has excellent corrosion resistance. When the metal oxoacid salt comprises tungstate, the tungstate ions will react with the zinc ions dissolved from the surface of the galvanized layer to form a difficultly soluble zinc tungstate oxide precipitate on the surface of the galvanized layer; when the metal oxoacid salt comprises molybdate, the molybdate ions can not only react with the zinc ions on the surface of the galvanized layer, but also can chemically react with the ferrous ions dissolved from the steel wire substrate to form a molybdate complex with good corrosion resistance on the surface of the galvanized steel wire, and finally form a dense protective film to hinder the contact between the corrosion medium and the galvanized layer. At the same time, the metal oxoacid salt is loaded on the carrier, which not only increases the dispersion stability, but also plays a slow release role, significantly prolonging the corrosion resistance life of the galvanized steel core. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also fall within the scope of protection of the present application.

[0029] In the following examples and comparative examples, Waterborne acrylic resin: Model: NeoCryl A614, Manufacturer: Covestro AG; Steel wire material: 45 steel.

[0030] Example 1 The preparation process of galvanized steel core includes the following steps: after degreasing, washing and drying the steel wire, it is immersed in zinc liquid at 420℃ for 120s, cooled to 280℃ at a cooling rate of 22℃ / s, held for 10min, then cooled to 200℃ at a cooling rate of 10℃ / s, held for 5min, and finally cooled to room temperature at a cooling rate of 6℃ / s to obtain galvanized steel wire. The galvanized steel wire is then placed in passivation solution at 40℃ for 12min, dried at 120℃ for 12min, and 19 steel wires are twisted together to obtain galvanized steel core. The passivation solution is composed of the following components by mass percentage: 16% aqueous acrylic resin, 0.6% sodium dodecylbenzenesulfonate, 2% filler, 1% silane coupling agent KH-550, and the balance being water; The filler is a mixture of silica-supported sodium tungstate and diatomaceous earth-supported sodium molybdate in a mass ratio of 1:1. The method for preparing silica-supported sodium tungstate includes the following steps: The silica was rinsed three times with 0.15 mol / L nitric acid solution, then washed with water until neutral, dried at 100℃ for 8 h, and ground to obtain activated silica with a particle size of 1 μm. Sodium tungstate was added to water (the mass ratio of sodium tungstate to water was 1:8), and then activated silica was added (the mass ratio of sodium tungstate to activated silica was 1:3). The mixture was heated to 100℃ and refluxed at 300 r / min for 5 h. After filtration, the mixture was dried at 80℃ for 15 h to obtain silica-supported sodium tungstate. A method for preparing sodium molybdate supported on diatomaceous earth includes the following steps: Diatomaceous earth was rinsed three times with 0.15 mol / L nitric acid solution, then washed with water until neutral, dried at 100℃ for 8 hours, and ground to obtain activated diatomaceous earth with a particle size of 3 μm. Sodium molybdate was added to water (the mass ratio of sodium molybdate to water was 1:8), and then activated diatomaceous earth was added (the mass ratio of sodium molybdate to activated diatomaceous earth was 1:3). The mixture was heated to 100℃ and refluxed at 300r / min for 5h. After filtration, the mixture was dried at 80℃ for 15h to obtain sodium tungstate supported on diatomaceous earth. A method for preparing steel-cored aluminum stranded wire for transmission lines includes the following steps: stranding 26 nickel-phosphorus alloy aluminum wires in one layer on the surface of a galvanized steel core to obtain steel-cored aluminum stranded wire for transmission lines.

[0031] Example 2 The preparation process of the galvanized steel core comprises the following steps: after the steel wire is degreased, washed, and dried, the steel wire is immersed in a zinc liquid at 450 DEG C for 100 s, is cooled to 260 DEG C at a cooling rate of 22 DEG C / s, is kept for 15 min, is cooled to 180 DEG C at a cooling rate of 10 DEG C / s, is kept for 8 min, is finally cooled to room temperature at a cooling rate of 6 DEG C / s, and the galvanized steel wire is obtained, the galvanized steel wire is placed in a passivation liquid at 50 DEG C for passivation for 10 min, is dried at 120 DEG C for 12 min, and 19 steel wires are stranded to obtain the galvanized steel core. The passivation liquid is composed of the following components in mass percentage: water-based acrylic resin 22%, calcium dodecylbenzenesulfonate 1.2%, filler 4%, silane coupling agent KH-560 3%, and the balance is water; The filler is silica supported sodium tungstate and diatomite supported sodium molybdate in a mass ratio of 1:1; The preparation method of the silica supported sodium tungstate comprises the following steps: The silica is leached with a 0.25 mol / L nitric acid solution twice, is washed with water until neutral, is dried at 120 DEG C for 6 h, is ground, and the activated silica with a particle size of 2 μm is obtained; The sodium tungstate is added to water (the mass ratio of the sodium tungstate to water is 1:12), the activated silica is further added (the mass ratio of the sodium tungstate to the activated silica is 1:5), the temperature is raised to 105 DEG C, the reflux reaction is carried out at 200 r / min for 4 h, filtration is carried out, and the silica supported sodium tungstate is obtained by drying at 100 DEG C for 10 h; The preparation method of the diatomite supported sodium molybdate comprises the following steps: The diatomite is leached with a 0.25 mol / L nitric acid solution twice, is washed with water until neutral, is dried at 120 DEG C for 6 h, is ground, and the activated diatomite with a particle size of 4 μm is obtained; The sodium molybdate is added to water (the mass ratio of the sodium molybdate to water is 1:12), the activated diatomite is further added (the mass ratio of the sodium molybdate to the activated diatomite is 1:5), the temperature is raised to 105 DEG C, the reflux reaction is carried out at 200 r / min for 4 h, filtration is carried out, and the diatomite supported sodium molybdate is obtained by drying at 100 DEG C for 10 h; A preparation method of a steel core aluminum strand for a power transmission line, comprising the following steps: 26 nickel-phosphorus alloy coated aluminum wires are stranded on the surface of a galvanized steel core in one layer to obtain the steel core aluminum strand for the power transmission line.

[0032] Example 3 The preparation process of the galvanized steel core comprises the following steps: after the steel wire is degreased, washed, and dried, it is immersed in a zinc liquid at 440 DEG C for 110 s, cooled to 270 DEG C at a cooling rate of 22 DEG C / s, kept for 12 min, then cooled to 190 DEG C at a cooling rate of 10 DEG C / s, kept for 6 min, finally cooled to room temperature at a cooling rate of 6 DEG C / s, to obtain a galvanized steel wire, the galvanized steel wire is placed in a passivation liquid at 45 DEG C for passivation for 11 min, dried at 120 DEG C for 12 min, and 19 steel wires are stranded to obtain the galvanized steel core; The passivation liquid is composed of the following components in mass percentage: water-based acrylic resin 19%, calcium dodecylbenzenesulfonate 0.8%, filler 3%, silane coupling agent KH-550 2%, and the balance is water; The filler is silica supported sodium tungstate and diatomite supported sodium molybdate in a mass ratio of 1:1; The preparation method of the silica supported sodium tungstate comprises the following steps: The silica is leached with a 0.2 mol / L nitric acid solution for 3 times, washed with water until neutral, dried at 110 DEG C for 7 h, ground, and activated silica with a particle size of 1 μm is obtained; The sodium tungstate is added to water (the mass ratio of sodium tungstate to water is 1:10), and then the activated silica is added (the mass ratio of sodium tungstate to activated silica is 1:4), heated to 105 DEG C, refluxed at 250 r / min for 4 h, filtered, and dried at 90 DEG C for 12 h to obtain the silica supported sodium tungstate; The preparation method of the diatomite supported sodium molybdate comprises the following steps: The diatomite is leached with a 0.2 mol / L nitric acid solution for 3 times, washed with water until neutral, dried at 110 DEG C for 7 h, ground, and activated diatomite with a particle size of 3 μm is obtained; The sodium molybdate is added to water (the mass ratio of sodium molybdate to water is 1:10), and then the activated diatomite is added (the mass ratio of sodium molybdate to activated diatomite is 1:4), heated to 105 DEG C, refluxed at 250 r / min for 4 h, filtered, and dried at 90 DEG C for 12 h to obtain the diatomite supported sodium molybdate; A preparation method of a steel core aluminum strand for power transmission line, comprising the following steps: 26 nickel-phosphorus alloy coated aluminum wires are stranded on the surface of the galvanized steel core in one layer to obtain the steel core aluminum strand for power transmission line.

[0033] Example 4 The difference between this example and example 3 is that the filler is silica supported sodium tungstate and diatomite supported sodium molybdate in a mass ratio of 2:1.

[0034] Example 5 The difference between this example and example 3 is that the filler is silica supported sodium tungstate and diatomite supported sodium molybdate in a mass ratio of 3:1.

[0035] Example 6 The difference between this example and Example 4 is only in the preparation process of the galvanized steel core, which comprises the following steps: after the steel wire is degreased, washed and dried, it is immersed in a zinc solution at 440℃ for 110s, first cooled to 270℃ at a cooling rate of 20℃ / s, then cooled to 190℃ at a cooling rate of 8℃ / s after 12min of heat preservation, and finally cooled to room temperature at a cooling rate of 5℃ / s. The galvanized steel wire is placed in a passivation solution at 45℃ for passivation for 11min, dried at 120℃ for 12min, and then 19 steel wires are stranded to obtain a galvanized steel core.

[0036] Example 7 The difference between this example and Example 4 is only in the preparation process of the galvanized steel core, which comprises the following steps: after the steel wire is degreased, washed and dried, it is immersed in a zinc solution at 440℃ for 110s, first cooled to 270℃ at a cooling rate of 18℃ / s, then cooled to 190℃ at a cooling rate of 6℃ / s after 12min of heat preservation, and finally cooled to room temperature at a cooling rate of 3℃ / s. The galvanized steel wire is placed in a passivation solution at 45℃ for passivation for 11min, dried at 120℃ for 12min, and then 19 steel wires are stranded to obtain a galvanized steel core.

[0037] Example 8 The difference between this example and Example 4 is only in the preparation process of the galvanized steel core, which comprises the following steps: after the steel wire is degreased, washed and dried, it is immersed in a zinc solution at 440℃ for 110s, first cooled to 270℃ at a cooling rate of 16℃ / s, then cooled to 190℃ at a cooling rate of 4℃ / s after 12min of heat preservation, and finally cooled to room temperature at a cooling rate of 1℃ / s. The galvanized steel wire is placed in a passivation solution at 45℃ for passivation for 11min, dried at 120℃ for 12min, and then 19 steel wires are stranded to obtain a galvanized steel core.

[0038] Example 9 The difference between this example and Example 3 is only that the filler is silica supported sodium tungstate.

[0039] Example 10 The difference between this example and Example 3 is only that the filler is diatomite supported sodium molybdate.

[0040] Example 11 The difference between this example and Example 3 is only that the filler is silica supported sodium tungstate and silica supported sodium molybdate in a mass ratio of 1:1. The preparation method of the silica supported sodium molybdate comprises the following steps: The activated silica was leached with 0.2 mol / L nitric acid solution for 3 times, washed with water until neutral, and dried at 110°C for 7 h to obtain activated silica with a particle size of 1 μm; The sodium molybdate was added to water (mass ratio of sodium molybdate to water was 1:10), and then the activated silica was added (mass ratio of sodium molybdate to activated silica was 1:4). The mixture was heated to 105°C and refluxed at 250 r / min for 4 h. After filtration, the mixture was dried at 90°C for 12 h to obtain the silica supported sodium molybdate.

[0041] Comparative Example 1 The difference between this comparative example and Example 3 is only that the filler is sodium tungstate.

[0042] Comparative Example 2 The difference between this comparative example and Example 3 is only that the filler is sodium molybdate.

[0043] The galvanized steel cores prepared in Examples 1-5 and 9-11 and Comparative Examples 1-2 were subjected to corrosion resistance testing according to the following method: Refer to GB / T 10125 The neutral salt spray test in 2021 “Artificial Atmosphere Corrosion Test Salt Spray Test” was used for testing. The spraying was 6wt% NaCl aqueous solution, and the temperature was 40°C. Every 15 min, the spraying was performed for 15 min. The surface corrosion of the sample was observed, and the time when the corrosion appeared on the surface of the sample was recorded. The test results are shown in Table 1: Table 1 Performance test results of the galvanized steel cores prepared in Examples 1-5 and 9-11 and Comparative Examples 1-2

[0044] 1. Compared with Examples 1-5, Examples 9-11 and Comparative Examples 1-2, the salt spray resistance time of the galvanized steel cores prepared in Examples 1-5 and 9-11 is much higher than that of Comparative Examples 1-2, indicating that loading the carrier (one of silica and diatomite) with metal oxyacid salt (one of tungstate and molybdate) and adding it to the passivation agent can greatly improve the corrosion resistance of the aluminum stranded wire of the steel core after passivation treatment.

[0045] 2. Compared with Examples 3-5 and Examples 9-11, the salt spray resistance time of the galvanized steel core prepared in Example 4 is longer than that of Examples 3, 5 and Examples 9-11, indicating that when the carrier loaded with metal oxyacid salt is silica loaded with sodium tungstate and diatomite loaded with sodium molybdate, and the mass ratio of silica loaded with sodium tungstate to diatomite loaded with sodium molybdate is 2:1, the corrosion resistance of the galvanized steel core after passivation treatment is further improved.

[0046] The tensile strength of the steel-cored aluminum stranded wires prepared in Example 4 and Examples 6-8 was tested according to the following method: Referring to GB / T 228.1 The tensile strength was determined according to 2021 Metallic Materials-Tensile Testing-Part 1: Method of Test at Room Temperature, wherein the separation speed of the tensile testing machine chuck was 50 mm / min. The test results are shown in Table 2: Table 2 Test results of the tensile strength of the steel-cored aluminum stranded wires prepared in Example 4 and Examples 6-8

[0047] Compared with Example 4 and Examples 6-8, the tensile strength of the steel-cored aluminum stranded wires prepared in Examples 6-7 is higher than that of Example 4 and Example 8, which indicates that in the preparation process of the galvanized steel core, by controlling the cooling rate of the three cooling stages, the first-stage cooling rate is 18-20 ℃ / s, the second-stage cooling rate is 6-8 ℃ / s, and the third-stage cooling rate is 3-5 ℃ / s, the tensile strength of the prepared galvanized steel core is further improved, so that the tensile strength of the steel-cored aluminum stranded wire is further improved.

[0048] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A steel-cored aluminum strand for a power transmission line, characterized by, The galvanized steel core comprises a galvanized steel core and an aluminum wire twisted on the surface of the galvanized steel core, and the preparation process of the galvanized steel core comprises the following steps: after the steel wire is degreased, washed and dried, it is immersed in a zinc solution, cooled after galvanizing, and a galvanized steel wire is obtained, and the galvanized steel wire is passivated, dried and twisted to obtain a galvanized steel core. The passivation solution used in the passivation process is composed of the following components by mass percentage: 16-22% of water-based acrylic resin, 0.6-1.2% of anionic surfactant, 2-4% of filler, 1-3% of silane coupling agent, and the balance of water. The filler comprises a carrier loaded metal oxoacid salt. The carrier loaded metal oxoacid salt is composed of silica loaded sodium tungstate and diatomite loaded sodium molybdate with a mass ratio of 1-3:

1.

2. A steel-cored aluminum strand for a power transmission line according to claim 1, characterized by, The preparation method of the carrier loaded metal oxoacid salt comprises the following steps: S1, the carrier is leached with a nitric acid solution, then washed with water until neutral, dried, ground, and an activated carrier is obtained; S2, the metal oxoacid salt is added to water, and then the activated carrier is added, refluxed, filtered, and dried to obtain a carrier loaded metal oxoacid salt.

3. A steel-cored aluminium stranded conductor for a power transmission line according to claim 2, characterised in that, The molar concentration of the nitric acid solution is 0.15-0.25 mol / L.

4. A steel-cored aluminum strand for a power transmission line according to claim 2, characterized by The mass ratio of the metal oxoacid salt to water is 1:8-12; The mass ratio of the metal oxoacid salt to the activated carrier is 1:3-5; The temperature of the reflux reaction is 100-105℃, and the time is 4-5h.

5. A steel-cored aluminum strand for a power transmission line according to claim 1, characterized by, The temperature of the passivation is 40-50℃, and the time is 10-12min; The temperature of the zinc solution is 420-450℃, and the time is 100-120s.

6. A steel-cored aluminum strand for a power transmission line according to claim 1, characterized by, The cooling comprises first-stage cooling, second-stage cooling and third-stage cooling, and the cooling rates of the first-stage cooling, the second-stage cooling and the third-stage cooling are different.

7. A steel-cored aluminium stranded conductor for a power transmission line according to claim 6, characterized in that, The first-stage cooling is cooling to 260-280℃ at a cooling rate of 18-20℃ / s, and the holding time is 10-15min; The second-stage cooling is cooling to 180-200℃ at a cooling rate of 6-8℃ / s, and the holding time is 5-8min; The third-stage cooling is cooling to room temperature at a cooling rate of 3-5℃ / s.

8. A steel-cored aluminium stranded conductor for a power transmission line according to claim 1, characterized in that, The anionic surfactant comprises one of sodium dodecyl benzene sulfonate and calcium dodecyl benzene sulfonate.

9. A steel-cored aluminium stranded conductor for a power transmission line according to claim 1, characterized in that, The silane coupling agent comprises one of silane coupling agent KH-550 and silane coupling agent KH-560.

Images