A corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, preparation process and overhead stranded wire

Abstract

The present application provides a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, a preparation process for the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, and an overhead stranded wire comprising the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire; the aluminum-magnesium-manganese alloy clad steel wire is composed of a steel wire and an aluminum-magnesium-manganese alloy layer uniformly coated on the surface of the steel wire and tightly bonded to the steel wire; the preparation process comprises preparing an aluminum-magnesium-manganese alloy ingot, rolling an aluminum-magnesium-manganese alloy coil, washing the aluminum-magnesium-manganese alloy coil with hot water, pre-treating the steel wire, laser coating welding, compression drawing, and then preparing the overhead stranded wire based on the aluminum-magnesium-manganese alloy clad steel wire; the aluminum-magnesium-manganese alloy layer has a uniform thickness, so that the aluminum-magnesium-manganese alloy layer and the steel wire have high concentricity after coating, reducing exposed steel, and at the same time, the laser longitudinal coating welding makes the weld sealing high, thereby improving the corrosion resistance of the aluminum-magnesium-manganese alloy clad steel wire.

Description

Technical Field

[0001] The present application relates to the technical field of stranded wires for overhead power transmission, and specifically to a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, a preparation process for the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, and an overhead stranded wire comprising the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire. Background Art

[0002] With the expansion of overhead stranded wire applications and the diversification of their environments, these scenarios and environments are impacting their lifespan and even causing them to fail. From the moment they are installed, overhead stranded wires are exposed to the air. The corrosive atmosphere, temperature, and humidity surrounding the lines gradually contaminate and erode them. This is particularly true in coastal and industrial areas, where the environment is particularly harsh. Corrosion and breakage, leading to failures in overhead stranded wires, are becoming increasingly prominent. Therefore, to improve the corrosion resistance of overhead stranded wires, aluminum-clad steel wire is currently being used instead of galvanized steel wire, or anti-corrosion oil is applied to the inner and outer surfaces of the stranded wire. Steel-clad wire is a bimetallic composite material formed by combining steel and aluminum rods through a continuous extrusion coating process. This process involves extruding semi-molten aluminum onto the steel wire to form the bimetallic composite. During the extrusion coating process, uneven wall thickness can occur due to factors such as the steel wire itself, the mold, and the processing equipment. This can lead to exposed steel on the thinner side of the aluminum layer, compromising the corrosion resistance of the aluminum-clad steel wire. The aluminum layer also exhibits varying corrosion resistance depending on its composition. Insufficient corrosion resistance will greatly reduce the life of aluminum-clad steel wire. Therefore, it is necessary to provide a clad steel wire with strong corrosion resistance and easy manufacturing to solve the above problems. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, which replaces the clad steel wire made of pure aluminum or aluminum alloy layer to improve the concentricity and strength of the clad steel wire and improve the corrosion resistance. It also provides a process flow for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, and an overhead stranded wire containing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire.

[0004] In the first aspect, in order to improve the corrosion resistance of aluminum-magnesium-manganese alloy clad steel wire, the present application provides a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, wherein the aluminum-magnesium-manganese alloy clad steel wire is composed of a steel wire and an aluminum-magnesium-manganese alloy layer uniformly coated on the surface of the steel wire and tightly bonded to the steel wire; the aluminum-magnesium-manganese alloy layer comprises the following components in weight percentage: 0.6%-0.8% manganese (Mn), 0.4%-0.6% iron (Fe), 0.1%-0.16% silicon (Si), 0.3%-0.5% magnesium (Mg), and the balance is aluminum (Al), and the weight percentage of aluminum is ≥97.94%; wherein the weight percentage ratio of manganese to iron is Mn / Fe=1.1-1.3, and the weight percentage of iron, manganese and magnesium ω(Fe+Mn+Mg)≤1.73%.

[0005] In a second aspect, the present application provides a process for preparing a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, comprising the following steps:

[0006] An aluminum-magnesium-manganese alloy ingot is prepared, wherein the aluminum-magnesium-manganese alloy layer comprises the following components, calculated by weight percentage: 0.6%-0.8% manganese (Mn), 0.4%-0.6% iron (Fe), 0.1%-0.16% silicon (Si), 0.3%-0.5% magnesium (Mg), and the balance being aluminum (Al), wherein the weight percentage of aluminum is ≥97.94%; wherein the weight percentage ratio of manganese to iron is 1.1-1.3, and the sum of the weight percentages of iron, manganese, and magnesium is ≤1.73%;

[0007] rolling the aluminum-magnesium-manganese alloy ingot into an aluminum-magnesium-manganese alloy coil having uniform thickness;

[0008] washing the aluminum-magnesium-manganese alloy coil with hot water and performing heat treatment;

[0009] removing the surface oxide layer of the steel wire and drawing it, and then polishing and cleaning the surface of the steel wire;

[0010] Cleaning and smoothing the coated surface of the aluminum-magnesium-manganese alloy coil, curling the aluminum-magnesium-manganese alloy coil and coating it on the polished and cleaned surface of the steel wire, and using a laser to weld two opposite sides of the aluminum-magnesium-manganese alloy coil to form a coating masterbatch;

[0011] The coated masterbatch is drawn at medium temperature to form a corrosion-resistant aluminum-magnesium-manganese clad steel wire in which the aluminum-magnesium-manganese alloy layer is uniformly coated on the surface of the steel wire and is tightly bonded to the steel wire.

[0012] Furthermore, the process of preparing an aluminum-magnesium-manganese alloy ingot with the same composition ratio as the aluminum-magnesium-manganese alloy layer includes the steps of: preparing an aluminum-magnesium-manganese alloy melt with the same composition ratio as the aluminum-magnesium-manganese alloy layer; and casting the aluminum-magnesium-manganese alloy melt in a mold to obtain an aluminum-magnesium-manganese alloy ingot.

[0013] Furthermore, preparing an aluminum-magnesium-manganese alloy melt with the same composition ratio as the aluminum-magnesium-manganese alloy layer includes the steps of: selecting an aluminum ingot with a mass fraction of 97.94% or more, heating the aluminum ingot to 840°C-870°C to melt it into aluminum liquid, then cooling it to 760°C-780°C, adding manganese (Mn), magnesium (Mg), iron (Fe), and silicon (Si) melts to the aluminum liquid according to the weight composition ratio and adding a refiner while stirring, stirring evenly to form an aluminum-magnesium-manganese alloy melt and letting it stand to maintain the temperature at 710-730°C.

[0014] Furthermore, during the casting process of the aluminum-magnesium-manganese alloy melt in the mold, the mold temperature is maintained at 280-320° C., the cooling water is maintained at 35-50° C., and the casting speed is 70-90 mm / s.

[0015] Furthermore, the process of rolling the aluminum-magnesium-manganese alloy ingot into an aluminum-magnesium-manganese alloy coil with uniform thickness includes the steps of: hot-rolling the aluminum-magnesium-manganese alloy ingot into an aluminum-magnesium-manganese alloy mother strip with a thickness of 2.5-3.5 mm, wherein the final rolling temperature is 300°C-320°C; and cold-rolling the aluminum-magnesium-manganese alloy mother strip into an aluminum-magnesium-manganese alloy coil with a thickness of 1-1.5 mm.

[0016] Furthermore, the heat treatment includes the steps of: controlling the temperature at 270-290° C. for low-temperature annealing and keeping the temperature for 10-12 hours, and then rapidly cooling the annealed aluminum-magnesium-manganese alloy strip by blasting.

[0017] Furthermore, the steel wire is selected from 72B high carbon steel wire, and the diameter of the steel wire after drawing is 2-3 mm.

[0018] Furthermore, the temperature of the medium-temperature drawing is controlled to be 200-250° C., and the drawing compression ratio of the medium-temperature drawing is 40%-50%.

[0019] In a third aspect, the present application also provides an overhead stranded wire comprising the above-mentioned corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire.

[0020] Compared with the prior art, the alloy layer of the clad steel wire provided by the present application has been chemically optimized in preparation, and the existing aluminum alloy layer is replaced by an aluminum-magnesium-manganese alloy layer, and the mass fraction ratio of magnesium, manganese and iron is optimized, thereby improving the corrosion resistance of the existing aluminum alloy clad steel wire; the preparation process of the aluminum-magnesium-manganese alloy clad steel wire provided by the present application includes: preparing aluminum-magnesium-manganese alloy ingots, rolling aluminum-magnesium-manganese alloy coils, cleaning aluminum-magnesium-manganese alloy coils, cleaning steel wires and drawing, cladding welding, compression drawing, and adding refined iron in the process of preparing the aluminum-magnesium-manganese alloy melt. agent, refines the grains, increases the density of the melt, and thus improves the corrosion resistance of the clad steel wire; and the preparation process of the present application makes the thickness of the rolled aluminum-magnesium-manganese alloy coil uniform, which can effectively reduce the exposed steel phenomenon caused by the thin aluminum alloy layer and the eccentricity of the steel core and the alloy layer, and enhances the concentricity of the steel core and the alloy layer; through the steel wire longitudinal cladding laser welding technology, laser welding has the advantages of a large depth-to-width ratio of the weld, high energy density, high welding efficiency, and easy operation. The use of laser welding can increase the welding speed, and the weld has good corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a process flow chart for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire of this application;

[0023] Figure 2 This is an electron microscope image showing that the aluminum-magnesium-manganese alloy coil and the steel wire are not tightly bonded;

[0024] Figure 3 This is an electron microscope image showing that the aluminum-magnesium-manganese alloy coil and steel wire are tightly combined.

[0025] Figure numerals: 1 - the bonding surface between the aluminum-magnesium-manganese alloy layer and the steel wire when the drawing compression ratio is 20-30%; 2 - the bonding surface between the aluminum-magnesium-manganese alloy layer and the steel wire when the drawing compression ratio is 40-45%. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] The present invention has discovered that commonly used aluminum alloys contain Fe and Si. Excessive Fe and Si content can easily form insoluble phases, disrupting the continuity of the aluminum alloy surface and reducing the alloy's corrosion resistance. On the other hand, a low Fe content can exacerbate pitting corrosion, further reducing corrosion resistance. In addition to the composition of the aluminum base itself, the continuous extrusion cladding process often produces uneven aluminum layer thickness, leading to exposed steel in thinner areas of the aluminum layer, compromising the corrosion resistance of the aluminum-clad steel wire.

[0028] Based on this, in order to improve the corrosion resistance of aluminum-clad steel wire, the corrosion resistance is improved by re-optimizing the composition of the aluminum layer outside the steel core, improving the production process of aluminum-clad steel wire, and improving the concentricity of the aluminum layer of the aluminum-clad steel wire. Specifically, in the present invention:

[0029] (1) Design a new aluminum-magnesium-manganese alloy to replace pure aluminum to improve the corrosion resistance of aluminum-clad steel wire;

[0030] (2) Using aluminum-magnesium-manganese alloy strips with uniform thickness, the steel core longitudinal laser welding process is used to increase production speed and obtain good corrosion resistance of the weld. After welding, the thickness of the outer alloy layer of the steel core is uniform and consistent, which solves the eccentricity problem.

[0031] In some embodiments of the present application, an aluminum-magnesium-manganese alloy clad steel wire is provided, which comprises a steel wire and an aluminum-magnesium-manganese alloy layer uniformly coated on the surface of the steel wire and tightly bonded to the steel wire, wherein the aluminum-magnesium-manganese alloy composition is as follows in weight percentage: 0.6%-0.8% manganese (Mn), 0.4%-0.6% iron (Fe), 0.1%-0.16% silicon (Si), 0.3%-0.5% magnesium (Mg), and the remainder is aluminum (Al), and the weight percentage of aluminum is ≥97.94%; wherein the weight percentage ratio of manganese to iron is Mn / Fe=1.1-1.3, and the weight percentage of iron, manganese, and magnesium ω(Fe+Mn+Mg)≤1.73%.

[0032] In some embodiments, a preparation process for manufacturing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire is also provided, comprising the following steps:

[0033] 1) preparing an aluminum-magnesium-manganese alloy ingot having the same composition ratio as the aluminum-magnesium-manganese alloy layer; selecting an aluminum ingot having a mass fraction greater than or equal to 97.94%, heating a smelting furnace for melting the aluminum ingot to 840° C.-870° C., melting the aluminum ingot into aluminum liquid, then cooling the aluminum liquid to 760° C.-780° C., adding manganese (Mn), magnesium (Mg), iron (Fe), and silicon (Si) melts to the aluminum liquid according to a weight composition ratio and stirring, while stirring the melt, adding a refiner to the smelting furnace, and standing the evenly stirred aluminum-magnesium-manganese alloy melt to maintain a temperature of 710-730° C. for preparation of casting;

[0034] In this process, the mass fraction ratio must be strictly followed. If the Fe content is too high (>0.7%) and the manganese content is too low (<0.6%), it will easily generate flake or needle-shaped FeAl3, which will aggravate the linear corrosion phenomenon in the alloy, destroy the continuity of the matrix, and reduce the corrosion resistance; if the Mn content is too high (>1.6%), it will easily undergo a substitution reaction with the Fe in the matrix, causing the pitting corrosion phenomenon in the matrix to deepen and affect the corrosion resistance; a small amount of Mg (≤0.4%) can significantly refine the grains of the alloy after annealing, reduce internal defects, and thus increase corrosion resistance, but excessive Mg (>5%) will reduce the welding coefficient of the alloy, affect the quality of the subsequent laser welding weld, and thus affect the corrosion resistance; at the same time, the Mn / Fe ratio must be controlled at 1.1-1.3. A ratio that is too small will lead to a decrease in the corrosion resistance of the alloy and a fast corrosion rate; a ratio that is too large will lead to excessive Mn content, which will undergo a substitution reaction with the Fe in the matrix and aggravate the pitting corrosion in the matrix;

[0035] During the stirring process of the melt, a refiner is added to refine the grain accuracy of the melt. The added refiner is specifically a titanium boron refiner, which can further refine the grains, reduce defects inside the matrix, and increase corrosion resistance.

[0036] Prepare a casting mold, maintain the mold temperature at 280-320°C, maintain the cooling water temperature at 35-50°C, and cast the aluminum-magnesium-manganese alloy melt at a casting speed of 70-90 mm / s. The cast aluminum-magnesium-manganese alloy ingot is square. Observation shows that the surface of the aluminum-magnesium-manganese alloy ingot has no cracks, no pores, no stratification, and presents an equiaxed grain shape.

[0037] 2) rolling the aluminum-magnesium-manganese alloy ingot prepared in step 1) into an aluminum-magnesium-manganese alloy coil with uniform thickness; placing the cast aluminum-magnesium-manganese alloy ingot into a rolling mill, heating and rolling the aluminum-magnesium-manganese alloy ingot into an aluminum-magnesium-manganese alloy mother strip with a uniform thickness of 2.5-3.5 mm, wherein the final rolling temperature is 300° C.-320° C., and then cold rolling the aluminum-magnesium-manganese alloy mother strip with uniform thickness to form an aluminum-magnesium-manganese alloy coil with a thickness of 1-1.5 mm.

[0038] 3) The aluminum-magnesium-manganese alloy coil rolled in step 2) is subjected to alkali washing to remove rolling oil and other impurities on the coil surface, exposing a clean and fresh aluminum-magnesium-manganese alloy coil to facilitate normal subsequent processing. After washing, the coil is subjected to low-temperature annealing in an annealing furnace at a temperature of 270-290° C. and maintained at this temperature for 10-12 hours. Finally, the annealed aluminum-magnesium-manganese alloy coil is rapidly cooled using a high-pressure blower. The high-pressure blower has both blowing and suction functions and operates oil-free. The air blown by the blower is cleaner, which removes impurities while cooling the aluminum-magnesium-manganese alloy coil, thereby keeping the surface of the alloy coil clean.

[0039] 4) removing the oxide layer on the surface of the steel wire and drawing it, and then grinding and cleaning the surface of the steel wire; selecting 72B high carbon steel wire rod, using a mechanical shelling machine to remove the thicker ferroferric oxide on the surface of the steel wire rod, if the oxide layer on the surface of the steel wire rod is very thin, using pickling or electrolytic pickling to remove the oxide layer on the surface of the steel wire rod; then drawing the steel wire rod to a wire diameter of 2-3 mm, and after drawing, grinding and cleaning the surface of the steel wire with a sanding machine.

[0040] 5) Select an aluminum-magnesium-manganese alloy coil with a thickness of 1-1.5mm, clean and smooth the coated surface of the aluminum-magnesium-manganese alloy coil, and then feed the aluminum-magnesium-manganese alloy coil and the treated steel wire into a continuous longitudinal laser welding machine at the same time. The laser power is controlled at 700-800 watts, the pulling speed is 20-25m / min, and the welding speed is controlled at 15-18m / min. If the laser power is higher than 800 watts, the magnesium in the aluminum-magnesium-manganese alloy will segregate from the center of the grain to the grain boundary, resulting in an increased tendency to produce weld crystallization cracks, prone to crack corrosion, and thus affecting the corrosion resistance of the aluminum-magnesium-manganese alloy clad steel wire; if the laser power is less than 700 watts, the penetration depth of the aluminum-magnesium-manganese alloy will be too shallow, making it impossible to weld effectively. If the welding speed is too fast, the penetration depth will be too shallow, making it impossible to weld the aluminum-magnesium-manganese alloy effectively. If the welding speed is too slow, the weld surface will be concave, the weld area will be thin, and exposed steel will appear during the subsequent drawing process. The aluminum-magnesium-manganese alloy coil is curled and coated on the surface of the steel wire in a continuous longitudinal laser welding machine, and two opposite sides of the aluminum-magnesium-manganese alloy coil are welded using laser welding to form a coated masterbatch.

[0041] 6) The coated masterbatch is subjected to 1-2 times of medium temperature drawing to remove the gap between the aluminum-magnesium-manganese alloy tube and the steel wire, so that the aluminum-magnesium-manganese alloy layer and the steel wire are tightly bonded to each other's interface penetration, wherein the medium temperature control temperature is 200-250°C, and the drawing compression ratio of the coated masterbatch is 40%-45%, finally forming the finished aluminum-magnesium-manganese clad steel wire.

[0042] Among them, the melting furnace, casting equipment, rolling equipment, annealing furnace, high-pressure blower, mechanical shelling machine, and continuous longitudinal laser welding machine are all conventional equipment and will not be described in detail here.

[0043] The preparation process of the aluminum-magnesium-manganese alloy clad steel wire of the present application is as follows: after the aluminum ingot is melted at high temperature in the early stage of preparation, a Mn, Mg, Fe, and Si melt is added for stirring, and a titanium-boron refiner is added for stirring, which can increase the grain size of the aluminum-magnesium-manganese alloy melt, reduce internal defects, and make the fusion of the various elements of the aluminum-magnesium-manganese alloy melt more uniform. The aluminum-magnesium-manganese alloy layer after casting is first hot-rolled and then cold-rolled, and the obtained aluminum-magnesium-manganese alloy coil has uniform thickness, no stratification and no pores; the preparation process of the present application first prepares the aluminum-magnesium-manganese alloy ingot, casts and rolls the aluminum-magnesium-manganese alloy coil, and then pre-treats the aluminum-magnesium-manganese alloy coil and the steel wire, and then performs laser longitudinal welding on the two, and obtains the aluminum-magnesium-manganese alloy clad steel wire masterbatch after compression and drawing. The preparation steps are relatively few, the process is clear, and the production of the aluminum-magnesium-manganese alloy clad steel wire is convenient. The laser welding weld has a large aspect ratio, high energy density, high welding efficiency, and is easy to operate. At the same time, laser welding can effectively increase the welding speed, make the weld tight and have good corrosion resistance.

[0044] In this application, the finished product of aluminum-magnesium-manganese clad steel wire was analyzed using an electron microscope to observe the interface formed between the aluminum-magnesium-manganese alloy and the steel wire. At a medium temperature of 200-250°C, the clad masterbatch was drawn and compressed at a drawing and compression ratio of 20-30% and 40-45%, respectively. The electron microscope images under the two conditions were observed, and it was found that: Figure 2 As shown in the figure, when the drawing compression ratio is 20-30%, the contact surfaces of the aluminum-magnesium-manganese alloy coil and the steel wire are not completely combined, while when the drawing compression ratio is 40-50%, Figure 3 As shown, the contact surfaces of the aluminum-magnesium-manganese alloy coil and the steel wire are tightly bonded.

[0045] Example 1

[0046] Example 1 provides a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, specifically, the aluminum-magnesium-manganese alloy clad steel wire is composed of a steel wire and an aluminum-magnesium-manganese alloy layer uniformly coated on the surface of the steel wire and tightly bonded to the steel wire. The composition ratio of the aluminum-magnesium-manganese alloy layer in the aluminum-magnesium-manganese alloy clad steel wire is as follows, by mass percentage: manganese (Mn): 0.6%, iron (Fe): 0.5%, silicon (Si): 0.1%, magnesium (Mg): 0.3%, aluminum (Al): 98.5%; and the ratio of the weight percentage of manganese to iron is 1.1-1.3, and the sum of the weight percentages of iron, manganese, and magnesium satisfies the requirement of ≤1.73%.

[0047] The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire described in this embodiment includes the following steps:

[0048] 1) heating a melting furnace to 840° C., melting an aluminum ingot with a purity of 99.7% into aluminum liquid, then cooling the aluminum liquid to 760° C., adding 0.6% manganese (Mn), 0.3% magnesium (Mg), 0.5% iron (Fe), and 0.1% silicon (Si) melt according to a mass composition ratio to the aluminum liquid and stirring, adding a titanium boron refiner during the stirring process, and standing the stirred aluminum-magnesium-manganese alloy melt to maintain a temperature of 710° C.;

[0049] Prepare a casting mold and maintain the temperature at 280° C., maintain the temperature of cooling water at 35° C., and cast the aluminum-magnesium-manganese alloy melt at a casting speed of 70 mm / s to form an aluminum-magnesium-manganese alloy ingot without delamination or pores.

[0050] 2) The aluminum-magnesium-manganese alloy ingot is placed in a rolling mill and rolled into an aluminum-magnesium-manganese alloy strip with a thickness of 2.5 mm and uniform thickness, with a final rolling temperature of 300° C., and then cold rolled into an aluminum-magnesium-manganese alloy coil with a thickness of 1 mm and uniform thickness.

[0051] 3) The aluminum-magnesium-manganese alloy coil is cleaned with alkali to remove oil stains on the surface, and then low-temperature annealing is performed at 270° C. and maintained for 10 hours. The annealed aluminum-magnesium-manganese alloy coil is then rapidly cooled using a blower to keep the surface of the aluminum-magnesium-manganese alloy coil dry and clean.

[0052] 4) Take 72B high carbon steel wire rod and clean it to remove the oxide layer on its surface. Then draw the steel wire rod to a wire diameter of 2 mm. After drawing, polish and clean it to remove impurities on the steel wire surface.

[0053] 5) Take a 1mm thick aluminum-magnesium-manganese alloy coil, clean it again, and feed it and the steel wire into a continuous longitudinal wrapping welder for welding. The laser power is controlled at 700-800 watts, the pulling speed is 20-25 m / min, and the welding speed is controlled at 15-18 m / min. The laser welder welds the two opposing sides of the aluminum-magnesium-manganese alloy coil to form the cladding masterbatch. Laser welding quickly joins the two opposing sides of the aluminum-magnesium-manganese alloy coil, wrapping the steel wire within the core.

[0054] 6) Drawing the coated masterbatch at a medium temperature of 200°C to achieve a drawing compression ratio of 40%, so that the aluminum-magnesium-manganese alloy layer and the steel wire contact surface penetrate each other to form an aluminum-magnesium-manganese alloy coated steel wire. The obtained finished product has strong corrosion resistance.

[0055] Example 2

[0056] The difference between the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire in Example 2 and Example 1 lies in the composition ratio of the aluminum-magnesium-manganese alloy clad steel wire, which is as follows: manganese (Mn): 0.65%, iron (Fe): 0.55%, silicon (Si): 0.13%, magnesium (Mg): 0.35%, and aluminum (Al): 98.32% by mass.

[0057] The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire described in this embodiment includes the following steps:

[0058] 1) heating a melting furnace to 850° C., melting an aluminum ingot with a purity of 99.7% into aluminum liquid, then cooling the aluminum liquid to 770° C., adding 0.65% manganese (Mn), 0.35% magnesium (Mg), 0.55% iron (Fe), and 0.13% silicon (Si) melt according to a mass composition ratio to the aluminum liquid and stirring, adding a titanium boron refiner during the stirring process, and standing the stirred aluminum-magnesium-manganese alloy melt to maintain a temperature of 720° C.;

[0059] Prepare a casting mold and maintain the temperature at 300° C., maintain the temperature of cooling water at 40° C., and cast the aluminum-magnesium-manganese alloy melt at a casting speed of 80 mm / s to form an aluminum-magnesium-manganese alloy ingot without delamination or pores.

[0060] 2) The aluminum-magnesium-manganese alloy ingot is placed in a rolling mill and rolled into an aluminum-magnesium-manganese alloy strip with a thickness of 3 mm and uniform thickness, with a final rolling temperature of 310° C., and then cold rolled into an aluminum-magnesium-manganese alloy coil with a thickness of 1.2 mm and uniform thickness.

[0061] 3) The aluminum-magnesium-manganese alloy coil is cleaned with alkali to remove oil stains on the surface, and then low-temperature annealing is performed at 280° C. and maintained for 11 hours. The annealed aluminum-magnesium-manganese alloy coil is then rapidly cooled using a blower to keep the surface of the aluminum-magnesium-manganese alloy coil dry and clean.

[0062] 4) Take 72B high carbon steel wire rod and clean it to remove the oxide layer on its surface. Then draw the steel wire rod to a wire diameter of 2.5 mm. After drawing, polish and clean it to remove impurities on the steel wire surface.

[0063] 5) Take a 1.2mm thick aluminum-magnesium-manganese alloy coil, clean it again, and feed it and the steel wire into a continuous longitudinal wrapping welder for welding. The laser power is controlled at 700-800 watts, the pulling speed is 20-25 m / min, and the welding speed is controlled at 15-18 m / min. The laser welder welds the two opposing sides of the aluminum-magnesium-manganese alloy coil to form the cladding masterbatch. Laser welding quickly joins the two opposing sides of the aluminum-magnesium-manganese alloy coil, wrapping the steel wire within the core.

[0064] 6) Drawing the coated masterbatch at a medium temperature of 230°C to achieve a drawing compression ratio of 43%, so that the aluminum-magnesium-manganese alloy layer and the steel wire contact surface penetrate each other to form an aluminum-magnesium-manganese alloy coated steel wire. The obtained finished product has strong corrosion resistance.

[0065] Example 3

[0066] The difference between the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire in Example 3 and Example 1 lies in the composition ratio of the aluminum-magnesium-manganese alloy clad steel wire, which is as follows: manganese (Mn): 0.7%, iron (Fe): 0.6%, silicon (Si): 0.16%, magnesium (Mg): 0.4%, and aluminum (Al): 98.14%.

[0067] The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire described in this embodiment includes the following steps:

[0068] 1) heating a melting furnace to 870° C., melting an aluminum ingot with a purity of 99.7% into aluminum liquid, then cooling the aluminum liquid to 780° C., adding 0.7% manganese (Mn), 0.4% magnesium (Mg), 0.6% iron (Fe), and 0.16% silicon (Si) melt according to a mass composition ratio to the aluminum liquid and stirring, adding a titanium boron refiner during the stirring process, and standing the stirred aluminum-magnesium-manganese alloy melt to maintain a temperature of 730° C.;

[0069] Prepare a casting mold and maintain the temperature at 310°C, maintain the cooling water temperature at 45°C, and cast the aluminum-magnesium-manganese alloy melt at a casting speed of 90 mm / s to form an aluminum-magnesium-manganese alloy ingot without delamination and pores.

[0070] 2) The aluminum-magnesium-manganese alloy ingot is placed in a rolling mill and rolled into an aluminum-magnesium-manganese alloy strip with a thickness of 3.5 mm and uniform thickness, with a final rolling temperature of 320° C., and then cold rolled into an aluminum-magnesium-manganese alloy coil with a thickness of 1.5 mm and uniform thickness.

[0071] 3) The aluminum-magnesium-manganese alloy coil is cleaned with alkali to remove oil stains on the surface, and then low-temperature annealing is performed at 290° C. and maintained for 12 hours. The annealed aluminum-magnesium-manganese alloy coil is then rapidly cooled using a blower to keep the surface of the aluminum-magnesium-manganese alloy coil dry and clean.

[0072] 4) Take 72B high carbon steel wire rod and clean it to remove the oxide layer on its surface. Then draw the steel wire rod to a wire diameter of 3 mm. After drawing, polish and clean it to remove impurities on the steel wire surface.

[0073] 5) Take a 1.5mm thick aluminum-magnesium-manganese alloy coil, clean it again, and feed it and the steel wire into a continuous longitudinal wrapping welder for welding. The laser power is controlled at 700-800 watts, the pulling speed is 20-25 m / min, and the welding speed is controlled at 15-18 m / min. The laser welder welds the two opposing edges of the aluminum-magnesium-manganese alloy coil to form the cladding masterbatch. Laser welding quickly joins the two opposing edges of the aluminum-magnesium-manganese alloy coil, wrapping the steel wire within the core.

[0074] 6) Drawing the coated masterbatch at a medium temperature of 250°C to achieve a drawing compression ratio of 45%, so that the aluminum-magnesium-manganese alloy layer and the steel wire contact surface penetrate each other to form an aluminum-magnesium-manganese alloy coated steel wire. The obtained finished product has strong corrosion resistance.

[0075] In order to test the quality of the aluminum-magnesium-manganese clad steel wire prepared in this application, the aluminum-magnesium-manganese alloy clad steel wire obtained by the preparation process of this application was subjected to corrosion resistance test and salt spray test. The specific test process is as follows:

[0076] 1) Immersion corrosion test

[0077] A 5kg sample and a 5kg sample of standard aluminum-clad steel wire were immersed in a 3.5% NaCl solution (pH = 7 ± 0.1). The beakers containing the sample and solution were placed in a blast heating oven controlled at 25°C. The test lasted for 8 weeks, with the NaCl solution replaced every two days to remove surface oxides from the samples. After the 8-week test, all surface oxides were removed, the surface solution was wiped dry, and the remaining alloy-clad steel wire sample was weighed. The corrosion rate of the aluminum-clad steel wire was calculated using the formula: R = (M0 - M1) / T, where M0 is the weight before corrosion, M1 is the weight after corrosion, and T is the corrosion time.

[0078] The three examples above and ordinary aluminum-clad steel wire were tested simultaneously. The test conditions were as follows: Al-Mg-Mn alloy clad steel wire samples and ordinary aluminum-clad steel wire samples were immersed in 3.5% NaCl solution, and the beakers containing the samples and solution were placed in a blast heating box at 25°C. The test lasted for 8 weeks, with the NaCl solution replaced every 2 weeks to remove oxides from the sample surfaces. The test results are shown in Table 1:

[0079] Table 1 Comparison of immersion corrosion test between aluminum-magnesium-manganese alloy clad steel and ordinary aluminum alloy clad steel

[0080]

[0081]

[0082] It can be seen from Table 1 that the corrosion rate of the aluminum-magnesium-manganese alloy clad steel sample in Example 1 is 0.07 g / h, the corrosion rate of the aluminum-magnesium-manganese alloy clad steel sample in Example 2 is 0.08 g / h, the corrosion rate of the aluminum-magnesium-manganese alloy clad steel sample in Example 3 is 0.1 g / h, and the corrosion rate of the ordinary aluminum clad steel sample is 0.28 g / h; in addition, after observing the aluminum-magnesium-manganese alloy clad steel and ordinary aluminum clad steel after the test, corrosion pits appeared on the surface of the ordinary aluminum clad steel sample, and slight corrosion appeared on the surface of the aluminum-magnesium-manganese alloy clad steel sample, which remained bright after being polished with sandpaper to remove rust. It can be concluded from the corrosion rate and the degree of surface corrosion that the corrosion resistance of the aluminum-magnesium-manganese alloy clad steel wire is higher than that of the ordinary aluminum clad steel wire.

[0083] 2) Salt spray test

[0084] Ordinary aluminum-clad steel wire and aluminum-magnesium-manganese alloy-clad steel wire were placed in a salt spray corrosion environment with a pH of 7, and the changes in each sample were observed. The experimental results are shown in Table 2:

[0085] Table 2 Comparison of salt spray test between aluminum-magnesium-manganese alloy clad steel and ordinary aluminum clad steel

[0086]

[0087]

[0088] It can be seen from Table 2 that in the same pH = 7 environment, white rust appears on the ordinary aluminum-clad steel sample after 480 hours. After polishing, the aluminum layer is still intact, but slight corrosion pits appear on the surface. The time for white rust to appear on the surface of the aluminum-magnesium-manganese alloy-clad steel samples in Example 1, Example 2 and Example 3 is longer than that of the ordinary aluminum-clad steel sample. After polishing, the aluminum-magnesium-manganese alloy layer is still intact and smooth. This shows that the corrosion resistance of the aluminum-magnesium-manganese alloy-clad steel is better than that of the ordinary aluminum-clad steel wire.

[0089] From the immersion corrosion test and salt spray test, it can be found that the aluminum-magnesium-manganese alloy clad steel prepared using the preparation process of the present application has a slow corrosion rate in the gold medal corrosion test, and it takes a long time for white rust to appear on the surface in the same salt spray environment. In addition, the surface alloy layer of the aluminum-magnesium-manganese alloy clad steel sample after the polishing test is complete and smooth, and its corrosion resistance is better than that of ordinary aluminum-clad steel.

[0090] In some other embodiments, an overhead stranded wire using the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire described in any of the above embodiments is also provided. By using this overhead stranded wire, the ability to cope with external humidity, temperature and dirty environment can be improved, the effectiveness of the use of the overhead stranded wire can be improved and the service life of the overhead stranded wire can be extended; the above stranded wires can be wires, cables, etc. commonly used in power transmission.

[0091] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, characterized in that: The aluminum-magnesium-manganese alloy clad steel wire is composed of a steel wire and an aluminum-magnesium-manganese alloy layer uniformly coated on the surface of the steel wire and tightly bonded to the steel wire; The aluminum-magnesium-manganese alloy layer includes the following components in weight percentage: 0.6%-0.8% manganese (Mn), 0.4%-0.6% iron (Fe), 0.1%-0.16% silicon (Si), 0.3%-0.5% magnesium (Mg), and the balance is aluminum (Al), and the weight percentage of aluminum is ≥97.94%; the ratio of the weight percentage of manganese to iron is 1.1-1.3, and the sum of the weight percentages of iron, manganese and magnesium is ≤1.73%.

2. A process for preparing corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire, characterized in that: The steps include: An aluminum-magnesium-manganese alloy ingot is prepared, comprising the following components, calculated by weight: 0.6%-0.8% manganese (Mn), 0.4%-0.6% iron (Fe), 0.1%-0.16% silicon (Si), 0.3%-0.5% magnesium (Mg), and the balance being aluminum (Al), wherein the weight percentage of aluminum is ≥97.94%; wherein the weight percentage ratio of manganese to iron is 1.1-1.3, and the sum of the weight percentages of iron, manganese, and magnesium is ≤1.73%; rolling the aluminum-magnesium-manganese alloy ingot into an aluminum-magnesium-manganese alloy coil having uniform thickness; washing the aluminum-magnesium-manganese alloy coil with hot water and performing heat treatment; Removing the surface oxide layer of the steel wire and drawing it, and then polishing and cleaning the surface of the steel wire; The coated surface of the aluminum-magnesium-manganese alloy coil is cleaned and smoothed, and the aluminum-magnesium-manganese alloy coil is curled and coated on the polished and cleaned surface of the steel wire. Two opposite sides of the aluminum-magnesium-manganese alloy coil are welded using a laser to form a coated masterbatch; the laser is welded using a continuous longitudinal laser welding machine, the laser power is controlled at 700-800 watts, the pulling speed is 20-25 m / min, and the welding speed is controlled at 15-18 m / min; The coated masterbatch is drawn at medium temperature to form a corrosion-resistant aluminum-magnesium-manganese clad steel wire in which the aluminum-magnesium-manganese alloy layer is uniformly coated on the surface of the steel wire and is tightly bonded to the steel wire.

3. The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire according to claim 2, characterized in that: The process of preparing an aluminum-magnesium-manganese alloy ingot with the same composition ratio as the aluminum-magnesium-manganese alloy layer includes the steps of: preparing an aluminum-magnesium-manganese alloy melt with the same composition ratio as the aluminum-magnesium-manganese alloy layer; and casting the aluminum-magnesium-manganese alloy melt in a mold to obtain an aluminum-magnesium-manganese alloy ingot.

4. The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire according to claim 3, characterized in that: The preparation of an aluminum-magnesium-manganese alloy melt having the same composition ratio as the aluminum-magnesium-manganese alloy layer comprises the following steps: An aluminum ingot with a mass fraction of 97.94% or more is selected, heated to 840°C-870°C to melt into aluminum liquid, and then cooled to 760°C-780°C. Manganese (Mn), magnesium (Mg), iron (Fe), and silicon (Si) melts are added to the aluminum liquid according to the weight composition ratio and a refiner is added while stirring. The mixture is stirred evenly to form an aluminum-magnesium-manganese alloy melt and the mixture is allowed to stand to maintain the temperature at 710-730°C.

5. The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire according to claim 3, characterized in that: During the casting process of the aluminum-magnesium-manganese alloy melt in the mold, the mold temperature is maintained at 280-320° C., the cooling water is maintained at 35-50° C., and the casting speed is 70-90 mm / s.

6. The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire according to claim 2, characterized in that: The process of rolling the aluminum-magnesium-manganese alloy ingot into an aluminum-magnesium-manganese alloy coil with uniform thickness comprises the following steps: hot-rolling the aluminum-magnesium-manganese alloy ingot into an aluminum-magnesium-manganese alloy mother strip with a thickness of 2.5-3.5 mm, wherein the final rolling temperature is 300° C.-320° C.; The aluminum-magnesium-manganese alloy mother strip is cold-rolled into an aluminum-magnesium-manganese alloy coil with a thickness of 1-1.5 mm.

7. The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire according to claim 2, characterized in that: The heat treatment comprises the steps of: controlling the temperature at 270-290° C. for low-temperature annealing and keeping the temperature for 10-12 hours, and then rapidly cooling the annealed aluminum-magnesium-manganese alloy strip by blasting.

8. The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire according to claim 2, characterized in that: The steel wire is 72B high carbon steel wire, and the diameter of the steel wire after drawing is 2-3 mm.

9. The process for preparing the corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire according to claim 2, characterized in that: The temperature of the medium-temperature drawing is controlled at 200-250° C., and the drawing compression ratio of the medium-temperature drawing is 40%-50%.

10. An overhead stranded conductor, characterized in that: The overhead stranded wire is made of a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire as described in claim 1 or a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire prepared by a preparation process for a corrosion-resistant aluminum-magnesium-manganese alloy clad steel wire as described in any one of claims 2-9.

Images