Production process of corrosion-resistant heat-resistant steel core aluminum alloy stranded wire

Abstract

The invention relates to the technical field of wire and cable manufacturing, and particularly discloses a production process of an anti-corrosion heat-resistant steel core aluminum alloy stranded wire. The process comprises four key steps of raw material preparation, wire drawing and on-line continuous annealing, twisting and vacuum pressure impregnation. Wherein the temperature difference between the aluminum wire and the steel core is controlled to be less than 10 DEG C in the stranding process, and deep penetration of anticorrosive grease is realized through a vacuum pressure impregnation process. According to the preparation method disclosed by the invention, the long-acting corrosion prevention and stable structure in the stranded wire is realized through vacuum impregnation and temperature difference control; the intrinsic corrosion resistance and heat resistance of the material are improved by adopting the zinc-aluminum rare earth coating steel core and the zirconium / rare earth microalloyed aluminum wire; excellent mechanical performance and conductive consistency of the product are ensured through on-line annealing and tension control, and the method is particularly suitable for harsh working conditions of high-voltage transmission lines.

Description

Technical Field

[0001] This application relates to the field of wire and cable manufacturing technology, and more specifically, it relates to a production process for corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire. Background Technology

[0002] In high-voltage and ultra-high-voltage transmission lines, steel-cored aluminum alloy stranded wire is a key component responsible for both power transmission and mechanical support. The steel core primarily provides mechanical strength, while the outer aluminum alloy wire dominates the conductivity. To increase transmission capacity, the industry commonly uses heat-resistant aluminum alloy monofilaments, which allow for long-term operation at higher temperatures (e.g., 150°C), thereby increasing transmission capacity without constructing new lines.

[0003] However, existing steel-cored aluminum alloy stranded wires exhibit significant limitations when operating in highly corrosive environments such as hot, humid, or coastal areas for extended periods. Firstly, their corrosion resistance is insufficient: current methods often employ a simple combination of ordinary galvanized steel cores and an external coating of anti-corrosion grease. During stranding, tiny gaps exist between the steel core and the aluminum wire. Traditional atmospheric pressure oiling processes struggle to completely fill these gaps with the anti-corrosion grease, allowing oxygen and moisture to easily penetrate and triggering electrochemical corrosion of the steel core. Ultimately, this leads to a decrease in overall conductor strength and a shortened lifespan. Secondly, process synergy is poor: during production, temperature differences between the aluminum wire and the steel core, as well as uneven tension between individual wires, can easily create residual stress within the stranded wire, affecting its long-term operational stability and fatigue resistance.

[0004] Therefore, existing technologies urgently need a systematic solution that can fundamentally improve the internal corrosion resistance and overall structural stability of steel-cored aluminum alloy stranded wires without significantly increasing production costs, so as to meet the operational requirements of long service life and high reliability of conductors under harsh working conditions. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a manufacturing process for corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire.

[0006] The first part of this application describes a manufacturing process for a corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire, which employs the following technical solution: A manufacturing process for corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire includes the following steps: (1) Raw material preparation: Provide electrical round aluminum rods, heat-resistant aluminum alloy single wires and galvanized steel wires; (2) Drawing and annealing: The electrical round aluminum rod is drawn into a heat-resistant aluminum alloy single wire, and the heat-resistant aluminum alloy single wire is subjected to online continuous annealing treatment; (3) Stranding: Strand multiple galvanized steel wires to form a steel core; on the outer periphery of the steel core, strand multiple heat-resistant aluminum alloy single wires treated in step (2) are stranded in layers to form an aluminum alloy stranded layer; during the stranding process, the temperature difference between the heat-resistant aluminum alloy single wires and the steel core is controlled to be less than 10℃. (4) Corrosion protection and sealing: The stranded wire obtained in step (3) is subjected to corrosion protection treatment by vacuum pressure impregnation process; the vacuum pressure impregnation process includes: placing the stranded wire in a sealed tank, evacuating to below -0.09MPa, then injecting anti-corrosion grease heated to 60-90℃, and applying pressure of 0.3-0.7MPa to maintain pressure.

[0007] By adopting the above technical solutions and using "online continuous annealing," the work-hardening internal stress generated during the drawing process is eliminated, improving the toughness and ductility of the single wire and providing a uniform mechanical property foundation for subsequent stranding. "Controlling the temperature difference between the heat-resistant aluminum alloy single wire and the steel core to less than 10℃" effectively avoids internal micro-gaps and stress concentration caused by differences in the thermal expansion coefficients of the materials, ensuring a tight bond between stranded wire layers. The core step, "vacuum pressure impregnation process," involves first evacuating the stranded wire to remove internal gas and moisture, and then injecting high-temperature anti-corrosion grease under pressure. This achieves complete filling of the gaps between the steel core and aluminum layers, forming a comprehensive protective system without dead angles. This fundamentally blocks the intrusion of corrosive media and significantly improves the long-term durability of the stranded wire in harsh environments such as humid heat and salt spray.

[0008] Optionally, in step (2), the online continuous annealing adopts induction heating or resistance heating, and the annealing temperature is controlled between 300-400℃.

[0009] By adopting the above technical solutions, induction heating or resistance heating can achieve rapid and uniform heat treatment, avoiding local overheating or uneven performance. Controlling the annealing temperature between 300-400℃ can effectively complete the recrystallization process of aluminum alloy, fully eliminate internal stress, and avoid excessive grain growth or surface oxidation. This ensures that the single wire achieves optimal plasticity while maintaining the required strength and conductivity, providing raw materials with consistent performance for subsequent stranding.

[0010] Optionally, during the stranding process in step (3), independent tension control is applied to each heat-resistant aluminum alloy single wire and steel core to control the tension fluctuation range within ±10% of the set value.

[0011] By adopting the above technical solution, the tension fluctuation is controlled within ±10% of the set value, ensuring that each single wire is subjected to uniform force during stranding, avoiding deformation differences caused by individual single wires being too tight or too loose, thereby improving the structural compactness and roundness of the stranded wire, enhancing its resistance to wind vibration and creep, and extending its service life.

[0012] Optionally, in step (3), the stranding equipment is equipped with a preforming device to preform the single wire into a bending shape consistent with the stranding direction before stranding.

[0013] By adopting the above technical solution, the design effectively reduces the rebound stress and micro-damage inside the single wire, making the stranded wire structure more stable and compact, while reducing the risk of surface scratches and improving the appearance quality and mechanical performance consistency of the finished product.

[0014] Optionally, the anti-corrosion grease is a composite lithium-based high-temperature anti-corrosion grease with a dropping point of not less than 180°C.

[0015] By adopting the above technical solution, high-temperature stability ensures that the grease adheres to the inside of the stranded wire for a long time, continuously playing the role of isolating oxygen and moisture, thereby adapting to the instantaneous high-temperature conditions that may occur when the line is overloaded or short-circuited, and ensuring the durability of the anti-corrosion effect.

[0016] Optionally, the preservative grease contains 1%-5% nano-graphite powder by weight.

[0017] By adopting the above technical solution, nano-graphite powder is added to the high-temperature grease. Its layered lubrication structure reduces the internal friction of the stranded wire during vibration and thermal expansion and contraction, thus mitigating fretting wear. At the same time, the nano-graphite powder can form a conductive network, promoting uniform current distribution within the stranded wire, preventing localized aggravation of electrochemical corrosion, and further improving the mechanical durability and corrosion resistance of the stranded wire.

[0018] Optionally, the coating of the galvanized steel wire is a zinc-aluminum-rare earth alloy coating, wherein the aluminum content is 4-6% and the rare earth content is 0.03-0.10%.

[0019] By adopting the above technical solution, the addition of aluminum forms a dense Al2O3 protective film, while rare earth elements refine the coating structure and enhance adhesion, together giving the coating superior corrosion resistance and crack propagation resistance. This coating preferentially undergoes a self-healing reaction in corrosive environments, significantly delaying the corrosion process of the steel substrate and providing a longer-lasting metallic protective barrier for the stranded wire.

[0020] Optionally, the heat-resistant aluminum alloy single wire is made from aluminum ingots by electromagnetic continuous casting and continuous rolling, and its composition contains 0.05-0.15wt% zirconium and 0.02-0.10wt% mixed rare earth elements.

[0021] By adopting the above technical solution, zirconium forms dispersed Al3Zr nanoparticles, effectively pinning grain boundaries, inhibiting recrystallization, and improving the material's high-temperature creep resistance; rare earth elements purify grain boundaries and enhance the density of the oxide film. Combining electromagnetic continuous casting and continuous rolling processes, rods with uniform composition and fine grains are obtained, ultimately ensuring that the single wire possesses excellent conductivity, heat resistance, and corrosion resistance, meeting the long-term operation requirements of high-strength transmission lines.

[0022] In summary, this application has the following beneficial effects: 1. Because this application uses a vacuum pressure impregnation process and combines it with temperature difference control during the stranding process, it achieves complete filling and uniform distribution of anti-corrosion grease in the gaps inside the stranded wire, while effectively reducing the internal stress caused by the difference in thermal expansion of materials, so that the stranded wire obtains overall and long-lasting anti-corrosion protection and a stable mechanical structure.

[0023] 2. In this application, zinc-aluminum-rare-earth alloy coated steel core and zirconium / rare-earth micro-alloyed heat-resistant aluminum alloy single wire are preferred. Through the synergistic optimization of the material system, the intrinsic corrosion resistance and high-temperature creep resistance of the stranded wire matrix are significantly improved, thus extending the service life of the conductor under harsh working conditions from the source.

[0024] 3. The method of this application, through the combined application of online continuous annealing, independent tension control and preforming device, ensures the uniformity of single wire performance and the precision of stranding process. The resulting stranded wire has a compact structure, low residual stress, and excellent roundness, fatigue resistance and conductivity consistency. Detailed Implementation

[0025] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources.

[0026] Example 1 The preparation process of a corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire: First, raw material preparation is carried out: 8A07 aluminum alloy electrical round rods with an aluminum content ≥99.70% are selected, with a diameter of 9.5mm, tensile strength of 115MPa, elongation of 8%, and resistivity of 0.02800Ω·mm² / m. After rolling, they are allowed to stand for 24 hours and pass the inspection. The heat-resistant aluminum alloy single wire uses an alloy composition containing 0.10wt% zirconium and 0.06wt% mixed rare earth elements. It is made into a single wire with a diameter of 3.60mm through electromagnetic continuous casting, continuous rolling, and drawing processes. The galvanized steel wire uses a zinc-aluminum-rare earth alloy coating, with an aluminum content of 5% and a rare earth content of 0.065%. The steel wire has a diameter of 2.40mm, and 7 strands are twisted together to form a steel core with a diameter of 7.20mm.

[0027] Next, wire drawing and annealing processes are carried out: the electrical round aluminum rod is drawn to a specified diameter of 3.60mm through multiple passes, and then continuously annealed online using induction heating, with the annealing temperature controlled at 350℃, to obtain heat-resistant aluminum alloy single wire.

[0028] The stranding process is carried out in stages: First, seven galvanized steel wires are stranded right-hand at a pitch of 145mm to form a steel core; then, two layers of heat-resistant aluminum alloy single wires are stranded around the outer periphery of the steel core. The inner layer of nine wires is stranded left-hand at a pitch of 187.5mm to a diameter of 14.4mm, and the outer layer of fifteen wires is stranded right-hand at a pitch of 237.5mm to a final diameter of 21.6mm. During the stranding process, the temperature difference between the heat-resistant aluminum alloy single wires and the steel core is strictly controlled to ≤8℃. Independent tension control is implemented for each single wire, and the fluctuation range is controlled within ±8%. At the same time, a pre-forming device is used to pre-form the single wires into a bending shape consistent with the stranding direction, ensuring a tight stranded structure and a smooth surface.

[0029] Finally, anti-corrosion sealing treatment is carried out: a composite lithium-based high-temperature anti-corrosion grease with a dropping point of 190℃ and 3% nano-graphite powder is added. The stranded wire is first placed in a sealed tank and vacuumed to -0.095MPa through a vacuum pressure impregnation process. Then, anti-corrosion grease at 75℃ is injected and pressure of 0.5MPa is applied and held for 30 minutes to allow the grease to fully penetrate into all gaps inside the stranded wire.

[0030] Example 2 The only difference between this embodiment and Embodiment 1 is the annealing process parameters. Online continuous annealing uses resistance heating, and the annealing temperature is set to 300℃. All other raw material ratios, stranding process parameters, and anti-corrosion sealing processes are exactly the same as in Embodiment 1. Testing showed that the resulting heat-resistant aluminum alloy single wire had a tensile strength of 172 MPa and an elongation of 9%. The stranded wire exhibited good overall performance, but the flexibility of the single wire was slightly lower than that of Embodiment 1.

[0031] Example 3 The difference between this embodiment and Embodiment 1 is that independent tension control is eliminated, and a traditional centralized tension control method is adopted, with the tension fluctuation range reaching ±25% of the set value. The remaining process parameters are consistent with those of Embodiment 1.

[0032] Example 4 The difference between this embodiment and Embodiment 1 is that the preforming device is not used during the twisting process. All other process parameters are exactly the same as in Embodiment 1.

[0033] Example 5 The difference between this embodiment and Embodiment 1 is that the anti-corrosion grease used is a composite lithium-based grease with a dropping point of 170°C, and no nano-graphite powder is added. All other process parameters remain the same as in Embodiment 1.

[0034] Example 6 The difference between this embodiment and Embodiment 1 is that the galvanized steel wire uses a common hot-dip galvanized layer, which does not contain aluminum or rare earth elements, and the zinc layer mass is 200g / m². All other process parameters are exactly the same as in Embodiment 1.

[0035] Example 7 The difference between this embodiment and Embodiment 1 is that the heat-resistant aluminum alloy single wire composition contains only 0.05wt% zirconium and no rare earth elements are added. All other process parameters remain the same as in Embodiment 1.

[0036] Example 8 The difference between this embodiment and Embodiment 1 is that the vacuum pressure impregnation process parameters are adjusted to: vacuum degree -0.085MPa, grease heating temperature 60℃, and injection pressure 0.3MPa. All other process parameters are exactly the same as in Embodiment 1.

[0037] Example 9 The difference between this embodiment and embodiment 1 is that a zinc-aluminum rare earth alloy coating (aluminum content 6%, rare earth content 0.10%) is used, the heat-resistant aluminum alloy single wire composition contains 0.15wt% zirconium and 0.10wt% mixed rare earth, the annealing temperature is 380℃, and the vacuum pressure impregnation parameters are vacuum degree -0.098MPa, grease temperature 85℃, and pressure 0.6MPa.

[0038] Comparative Example 1 The difference between this comparative example and Example 1 is that the vacuum pressure impregnation process is omitted, and a traditional atmospheric pressure coating method is used instead. The stranded wire is directly immersed in anti-corrosion grease at 75°C for 30 minutes, without vacuum extraction or pressure maintenance steps. All other process parameters are exactly the same as in Example 1.

[0039] Comparative Example 2 The difference between this comparative example and Example 1 is that the temperature difference control during the stranding process is eliminated, allowing the natural temperature difference between the heat-resistant aluminum alloy single wire and the steel core to reach 25-30℃. All other process parameters remain the same as in Example 1.

[0040] Comparative Example 3 The difference between this comparative example and Example 1 is that the online continuous annealing process is omitted, and the heat-resistant aluminum alloy single wire is used directly for stranding after drawing. All other process parameters are exactly the same as in Example 1.

[0041] Comparative Example 4 The difference between this comparative example and Example 1 is that the independent tension control system is eliminated, and a passive feeding method is adopted, resulting in a tension fluctuation range of over ±30%. All other process parameters remain the same as in Example 1.

[0042] Comparative Example 5 The difference between this comparative example and Example 1 is that: a common hot-dip galvanized steel core is used, the zinc layer does not contain aluminum or rare earth elements, and the zinc layer mass is 150 g / m². All other process parameters are exactly the same as in Example 1.

[0043] Comparative Example 6 The difference between this comparative example and Example 1 is that: ordinary calcium-based anti-corrosion grease is used, with a dropping point of 120°C, and no nano-graphite powder is added. All other process parameters remain the same as in Example 1.

[0044] Comparative Example 7 This comparative example eliminates three key processes: vacuum pressure impregnation, temperature difference control, and online annealing. It adopts a traditional production process: atmospheric pressure oiling, natural temperature difference (25-30℃), and no annealing treatment. The remaining raw materials are the same as in Example 1.

[0045] Detection methods

[0046] 1. Salt spray corrosion test According to GB / T10125-2012 standard, a 5% NaCl solution was used at a temperature of 35℃ for continuous spraying, and the time when the first red rust appeared was recorded.

[0047] 2. High-temperature durability test The sample was placed in an oven at 180℃ for 1000 hours, and the tensile strength retention rate and grease loss were measured after the test.

[0048] 3. DC resistance test According to GB / T3048.4-2007 standard, the DC resistance at 20℃ is measured using a resistance tester.

[0049] 4. Vibration fatigue test According to GB / T4909.10-2009 standard, with an amplitude of ±1.5mm and a frequency of 30Hz, record the number of cycles at which the sample breaks.

[0050] 5. Structural stability test The pitch change rate was measured by performing 100 thermal cycles within a temperature range of -40℃ to 150℃.

[0051] 6. Bending performance test According to GB / T4909.8-2009 standard, bend the stranded wire 180° around a round bar with a diameter of 3 times and check the surface condition.

[0052] 7. Grease Filling Test The percentage of grease-covered area on the cross-section of the stranded wire was measured using a cross-sectional analysis method.

[0053] Table 1 Detection Data sample Salt spray test (h) Tensile strength retention rate (%) DC resistance (Ω / km) Vibration fatigue (10,000 cycles) Pitch change rate (%) Bending performance Grease filling degree (%) Example 1 2000 95.2 0.1140 50.2 1.2 qualified 95 Example 2 1980 94.5 0.1143 49.8 1.3 qualified 94 Example 3 1850 92.1 0.1152 42.5 2.8 qualified 93 Example 4 1900 93.2 0.1148 45.3 2.1 minor cracks 92 Example 5 1500 90.5 0.1145 48.6 1.5 qualified 88 Example 6 800 94.8 0.1142 49.5 1.3 qualified 94 Example 7 1800 87.3 0.1158 48.9 1.4 qualified 94 Example 8 1600 93.8 0.1146 49.1 1.6 qualified 85 Example 9 3000 96.5 0.1135 52.3 0.8 qualified 98 Comparative Example 1 500 91.2 0.1150 47.8 2.5 qualified 65 Comparative Example 2 1200 88.5 0.1172 38.6 4.2 qualified 90 Comparative Example 3 1800 82.1 0.1185 45.2 3.1 fracture 92 Comparative Example 4 1900 90.3 0.1163 15.2 5.6 loose 91 Comparative Example 5 200 93.5 0.1145 48.9 1.4 qualified 93 Comparative Example 6 300 85.2 0.1168 46.3 2.8 qualified 75 Comparative Example 7 200 78.5 0.1215 25.6 8.5 fracture 60 As can be seen from Example 1 and Comparative Example 1, and in conjunction with Table 1, after eliminating the vacuum pressure impregnation process and adopting the traditional atmospheric pressure coating method, the grease filling degree decreased from 95% to 65%, and the salt spray test time dropped sharply from 2000 hours to 500 hours. This indicates that the vacuum pressure impregnation process is key to achieving sufficient corrosion protection inside the stranded wire, and can significantly improve the grease penetration depth and corrosion protection effect.

[0054] Combining Example 1 and Comparative Example 2 with Table 1, it can be seen that after eliminating temperature difference control during the stranding process, the pitch change rate increased from 1.2% to 4.2%, the DC resistance increased from 0.1140 Ω / km to 0.1172 Ω / km, and the vibration fatigue life decreased from 502,000 cycles to 386,000 cycles. This indicates that controlling the temperature difference between the single wire and the steel core plays an important role in maintaining the stability, electrical performance, and fatigue resistance of the stranded wire structure.

[0055] As can be seen from Example 1 and Comparative Example 3, and Table 1, after eliminating the online continuous annealing process, the tensile strength retention rate decreased from 95.2% to 82.1%, fracture occurred in the bending test, and the DC resistance increased to 0.1185 Ω / km. This indicates that online annealing can effectively eliminate internal stress in materials and significantly improve the product's flexibility, high-temperature durability, and electrical conductivity.

[0056] As can be seen from Example 1 and Comparative Example 4, and Table 1, after eliminating independent tension control, the vibration fatigue life plummeted from 502,000 cycles to 152,000 cycles, while the pitch change rate increased from 1.2% to 5.6%. This demonstrates that precise tension control is crucial for ensuring the tightness and fatigue resistance of the stranded wire structure.

[0057] As can be seen from Example 1 and Comparative Example 5, and in conjunction with Table 1, replacing the zinc-aluminum rare earth coating with a conventional hot-dip galvanized layer reduced the salt spray test time from 2000 hours to only 200 hours. This indicates that the zinc-aluminum rare earth alloy coating can significantly improve the intrinsic corrosion resistance of the steel core, providing an important guarantee for long-term corrosion protection.

[0058] As can be seen from Example 1 and Comparative Example 6, and Table 1, after using ordinary calcium-based grease, the tensile strength retention rate decreased from 95.2% to 85.2%, the grease filling degree decreased to 75%, and the salt spray test time decreased to 300 hours. This indicates that high-temperature composite lithium-based grease and its additives can significantly improve the temperature resistance and adhesion of grease, ensuring long-term protective effects.

[0059] As can be seen from Example 1 and Comparative Example 7, and Table 1, after simultaneously eliminating the three key processes, all performance indicators of the product deteriorated, with the salt spray test time reduced to only 200 hours, vibration fatigue life to 256,000 cycles, and tensile strength retention rate to 78.5%. This fully demonstrates the synergistic effect and overall advantages of each process step in the technical solution of this application.

[0060] Combining Examples 1 and 2 with Table 1, it can be seen that when the annealing temperature is reduced from 350℃ to 300℃, the overall performance of the product decreases slightly but still remains at a good level. The tensile strength retention rate decreases from 95.2% to 94.5%, and the salt spray test time decreases from 2000 hours to 1980 hours. This indicates that the annealing temperature can guarantee product performance within the range of 300-400℃, with 350℃ being the optimal choice.

[0061] As can be seen from Examples 1 and 3 and Table 1, when independent tension control was removed, the vibration fatigue life decreased from 502,000 cycles to 425,000 cycles, while the pitch change rate increased from 1.2% to 2.8%. This further confirms the significant impact of independent tension control on the structural stability of the product.

[0062] Combining Examples 1 and 4 with Table 1, it can be seen that when the preforming device is not used, the product exhibits slight cracks during bending tests, and the vibration fatigue life decreases from 502,000 cycles to 453,000 cycles. This indicates that the preforming device can effectively improve the surface quality and mechanical properties of the stranded wire.

[0063] Combining Examples 1 and 5 with Table 1, it can be seen that when using a grease with a low dropping point and without adding nano-graphite powder, the grease filling degree decreased from 95% to 88%, and the salt spray test time decreased from 2000 hours to 1500 hours. This demonstrates the synergistic effect of the high-temperature grease system and nano-additives in improving the anti-corrosion effect.

[0064] Combining Examples 1 and 6 with Table 1, it can be seen that when using a conventional hot-dip galvanized layer, the salt spray test time drops sharply from 2000 hours to 800 hours, but other performance indicators remain largely unchanged. This highlights the unique advantages of zinc-aluminum rare earth coatings in corrosion protection. As can be seen from Examples 1 and 7 and Table 1, when no rare earth elements are added to the heat-resistant aluminum alloy, the tensile strength retention rate decreases from 95.2% to 87.3%, and the high-temperature durability performance declines significantly. This indicates that rare earth elements play an important role in improving the high-temperature performance of materials.

[0065] Combining Examples 1 and 8 with Table 1, it can be seen that when the vacuum pressure impregnation process parameters are reduced, the grease filling degree decreases from 95% to 85%, and the salt spray test time decreases from 2000 hours to 1600 hours. This demonstrates the importance of optimizing process parameters in ensuring corrosion protection.

[0066] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A manufacturing process for corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire, characterized in that, Includes the following steps: (1) Raw material preparation: Provide electrical round aluminum rods, heat-resistant aluminum alloy single wires and galvanized steel wires; (2) Drawing and annealing: The electrical round aluminum rod is drawn into a heat-resistant aluminum alloy single wire, and the heat-resistant aluminum alloy single wire is subjected to online continuous annealing treatment; (3) Stranding: Strand multiple galvanized steel wires to form a steel core; on the outer periphery of the steel core, strand multiple heat-resistant aluminum alloy single wires treated in step (2) are stranded in layers to form an aluminum alloy stranded layer; during the stranding process, the temperature difference between the heat-resistant aluminum alloy single wires and the steel core is controlled to be less than 10℃. (4) Corrosion protection and sealing: The stranded wire obtained in step (3) is subjected to corrosion protection treatment by vacuum pressure impregnation process; The vacuum pressure impregnation process includes: placing the stranded wire in a sealed container, evacuating it to below -0.09 MPa, then injecting anti-corrosion grease heated to 60-90°C, and applying a pressure of 0.3-0.7 MPa to maintain the pressure.

2. The production process of the corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire according to claim 1, characterized in that, In step (2), the online continuous annealing adopts induction heating or resistance heating, and the annealing temperature is controlled between 300-400℃.

3. The production process of the corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire according to claim 1, characterized in that, During the stranding process in step (3), independent tension control is applied to each heat-resistant aluminum alloy single wire and steel core to keep the tension fluctuation range within ±10% of the set value.

4. The production process of the corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire according to claim 1, characterized in that, In step (3), the stranding equipment is equipped with a preforming device, which allows the single wire to be preformed into a bending shape consistent with the stranding direction before stranding.

5. The production process of the corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire according to claim 1, characterized in that, The anti-corrosion grease is a composite lithium-based high-temperature anti-corrosion grease with a dropping point of not less than 180°C.

6. The production process of the corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire according to claim 5, characterized in that, The preservative grease contains 1%-5% nano-graphite powder by weight.

7. The production process of the corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire according to claim 1, characterized in that, The coating of the galvanized steel wire is a zinc-aluminum-rare earth alloy coating, wherein the aluminum content is 4-6% and the rare earth content is 0.03-0.10%.

8. The production process of the corrosion-resistant and heat-resistant steel-cored aluminum alloy stranded wire according to claim 1, characterized in that, The heat-resistant aluminum alloy single wire is made from aluminum ingots by electromagnetic continuous casting and continuous rolling, and its composition contains 0.05-0.15wt% zirconium and 0.02-0.10wt% mixed rare earth elements.