High-strength aluminum-clad steel wire and preparation method thereof

Abstract

The present application provides a high-strength aluminum-clad steel wire and a preparation method thereof. The preparation method of the high-strength aluminum-clad steel wire comprises the following steps: preparing a steel wire; hot-rolling the steel wire until the steel wire is austenitized, and then using the heat after the hot-rolling treatment of the steel wire to perform a salt bath quenching treatment on the austenitized steel wire until the steel wire is sorbitized; removing the oxide scale on the surface of the sorbitized steel wire, and then adjusting the shape of the steel wire; coating the outer periphery of the steel wire with aluminum wire to form a busbar; and drawing the busbar.

Description

Technical Field

[0001] The present application relates to the technical field of aluminum clad steel wires, and in particular to a high-strength aluminum clad steel wire and a preparation method thereof. Background Art

[0002] Aluminum-clad steel wire is a bimetallic material formed by stretching a layer of aluminum on the outer periphery of steel. During the preparation process of existing aluminum-clad steel wire, the steel needs to be heated multiple times at intervals to achieve austenitization and sorbitization of the steel, resulting in high production costs and low production efficiency. Summary of the invention

[0003] The present application provides a high-strength aluminum-clad steel wire and a preparation method thereof to solve the problems of high production cost and low production efficiency of the aluminum-clad steel wire in the prior art.

[0004] In a first aspect, the present application provides a method for preparing a high-strength aluminum-clad steel wire, comprising the following steps:

[0005] preparing steel wire;

[0006] Hot rolling the steel wire until the steel wire is austenitized, and then using the heat from the hot rolling of the steel wire to perform salt bath quenching on the austenitized steel wire until the steel wire is austenitized;

[0007] removing the oxide scale on the surface of the steel wire after being subjected to sorbitization, and then adjusting the shape of the steel wire;

[0008] After coating the outer circumference of the steel wire with an aluminum layer, a busbar is formed;

[0009] The busbar is subjected to a drawing process.

[0010] In a possible implementation, the steel wire includes carbon, manganese, silicon, and chromium, the carbon element accounts for 0.85%-0.90% of the total mass of the steel wire, the manganese element accounts for 0.60%-0.90% of the total mass of the steel wire, the silicon element accounts for 0.35%-1.2% of the total mass of the steel wire, and the chromium element accounts for less than or equal to 0.40% of the total mass of the steel wire.

[0011] In a possible implementation manner, when the busbar is subjected to a drawing process, the busbar is subjected to a multi-pass drawing process, and a total compression rate of the busbar is controlled to be less than or equal to 80%.

[0012] In a possible implementation manner, the number of times the busbar is drawn in the multi-pass drawing process is less than or equal to 9 times.

[0013] In a possible implementation manner, the drawing speed of the busbar is 4-8 m / s.

[0014] In a possible implementation manner, the temperature of the hot rolling treatment on the steel wire is 900-950° C., and the hot rolling treatment time is 1-2 min.

[0015] In a possible implementation manner, the temperature of the salt bath quenching treatment on the steel wire is 500-580° C., and the salt bath quenching treatment time is 15-50 seconds.

[0016] In a possible implementation manner, the degree of austenitization of the steel wire reaches more than 98%, and the degree of formateization of the steel wire reaches more than 90%.

[0017] In a possible implementation manner, the die used for drawing the busbar is a pressure die and a tungsten steel wire drawing die.

[0018] In a second aspect, the present application also provides a high-strength aluminum-clad steel wire, which is prepared using the above-mentioned method for preparing the high-strength aluminum-clad steel wire.

[0019] After the steel wire is hot-rolled to austenitize, the present application directly uses the remaining heat after the hot-rolling treatment to perform salt bath quenching on the steel wire, so that the austenitized steel wire is austenitized, so that the steel wire can be continuously heated online in the same production workshop. Only a single continuous heating of the steel wire is required to make the steel wire performance meet actual needs, avoiding multiple heating of the steel wire, thereby reducing production costs and improving production efficiency. In addition, the present application only performs a single drawing treatment on the steel wire, and the steel wire is drawn after the salt bath quenching treatment is completed. The salt bath quenching treatment can improve the structural strength of the steel wire and reduce the processing deformation of the steel wire during subsequent descaling, shape adjustment and drawing treatment, thereby ensuring that the final prepared aluminum-clad steel wire has better tensile strength and plastic toughness and other properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 1 is a schematic flow chart of a method for preparing a high-strength aluminum-clad steel wire according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic structural diagram of a high-strength aluminum-clad steel wire in one embodiment of the present application.

[0022] Description of main component symbols:

[0023] Preparation method of high-strength aluminum-clad steel wire 100

[0024] High strength aluminum clad steel wire 200

[0025] Steel core layer 201

[0026] Aluminum layer 202

[0027] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0028] The following description will refer to the accompanying drawings to more fully describe the content of the present application. Shown in the accompanying drawings are exemplary embodiments of the present application. However, the present application can be implemented in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. These exemplary embodiments are provided to make the present application thorough and complete, and to fully convey the scope of the present application to those skilled in the art. Similar reference numerals represent identical or similar components.

[0029] The terms used herein are only used for the purpose of describing specific exemplary embodiments and are not intended to limit the present application. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to also include the plural forms. In addition, when used herein, "including" and / or "comprising" and / or "having", integers, steps, operations, components and / or components, but do not exclude the existence or addition of one or more other features, regions, integers, steps, operations, components and / or groups thereof.

[0030] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. In addition, unless explicitly defined herein, terms such as those defined in general dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant technology and the content of this application, and will not be interpreted as an idealized or overly formal meaning.

[0031] Generally, in the production process of existing aluminum-clad steel wires, the steel needs to be heated multiple times at intervals to achieve austenitization and sorbitization of the steel, resulting in high production costs and low production efficiency of aluminum-clad steel wires. For example, the existing production process of aluminum-clad steel wires is mostly to remove the oxide scale of the steel wire after hot rolling and then perform rough drawing, then perform lead bath quenching on the rough drawn steel wire, and finally, after the aluminum layer is coated on the periphery of the lead bath quenched steel wire, the bimetallic busbar formed by the two is subjected to secondary drawing.

[0032] The production process of this aluminum-clad steel wire is generally to complete the smelting and hot rolling of the steel wire in the upstream steel plant production workshop, store the steel wire for more than half a month, and then transport it to the downstream aluminum-clad steel wire production workshop for subsequent processing. After the steel wire is transported to the aluminum-clad steel wire production workshop, it needs to be heated again to make it austenitized and then quenched in a lead bath to make it austenitized. This heat treatment method belongs to secondary offline heat treatment. Compared with online heat treatment, offline heat treatment is less efficient and causes a lot of energy waste.

[0033] Therefore, the embodiment of the present application provides a method for preparing high-strength aluminum-clad steel wire. After the steel wire is hot-rolled to austenitize, the remaining heat after the hot-rolling treatment is directly used to perform salt-bath quenching on the steel wire, so that the austenitized steel wire is austenitized, so that the steel wire can be continuously heated online in the same production workshop. Only a single continuous heating of the steel wire is required to make the performance of the steel wire meet actual needs, avoiding multiple heating of the steel wire, thereby reducing production costs and improving production efficiency. In addition, the present application only performs a single drawing treatment on the steel wire, and the steel wire is drawn after the salt-bath quenching treatment is completed. The salt-bath quenching treatment can improve the structural strength of the steel wire and reduce the processing deformation of the steel wire during subsequent descaling, shape adjustment and drawing treatment, thereby ensuring that the aluminum-clad steel wire finally prepared has better tensile strength and plastic toughness and other properties.

[0034] Among them, the preparation method of the high-strength aluminum-clad steel wire of the present application can complete the hot rolling treatment and salt bath quenching treatment of the steel wire through online heat treatment in the steel wire production workshop, so that the steel wire has completed the sorbitization treatment when leaving the steel plant. When the steel wire is transported to the downstream aluminum-clad steel wire production workshop, there is no need to heat treat the steel wire to make it austenitized and sorbitized, avoiding the steel wire in the downstream aluminum-clad steel wire production workshop. Secondary heating, thereby reducing energy consumption in the steel wire production process and reducing the production cost of the steel wire.

[0035] The specific implementation methods of the present application are further described in detail below with reference to the accompanying drawings.

[0036] like Figure 1 As shown, this embodiment provides a method 100 for preparing a high-strength aluminum-clad steel wire, comprising the following steps:

[0037] S1. Prepare steel wire.

[0038] In this step, the steel wire includes carbon, manganese, silicon and chromium, and the rest of the steel wire is iron and other impurities. Carbon, manganese, silicon and chromium are performance enhancing elements that can improve the performance of the steel wire.

[0039] The percentage of carbon element in the total mass of the steel wire is 0.85%-0.90%. It is understandable that the percentage of carbon element in the total mass of the steel wire can be 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, etc.

[0040] In this embodiment, the percentage of carbon element in the total mass of the steel wire is 0.85%-0.90%, which can enhance the strength of the steel wire without reducing the plastic toughness of the steel wire, make the internal structure of the steel wire more uniform, and reduce the segregation of carbides. The carbon element added to the steel wire can utilize the solid solution strengthening mechanism of carbon element to improve the tensile strength of the steel wire. If the percentage of carbon element in the total mass of the steel wire is lower than this range, the solid solution strengthening effect of carbon element is weakened, which is not conducive to improving the tensile strength of the steel wire. If the percentage of carbon element in the total mass of the steel wire is higher than this range, on the one hand, the brittleness of the steel wire will increase, resulting in poor toughness of the steel wire, and on the other hand, the risk of carbon segregation will increase, making the steel wire prone to wire breakage during processing, affecting production efficiency and product quality.

[0041] The percentage of manganese element in the total mass of the steel wire is 0.60%-0.90%. It is understandable that the percentage of manganese element in the total mass of the steel wire can be 0.60%, 0.70%, 0.80%, 0.90%, etc.

[0042] In this embodiment, manganese can form a solid solution with iron, thereby enhancing the strength of the steel wire. If the percentage of manganese in the total mass of the steel wire is lower than this range, the solid solution strengthening effect of manganese is weakened, which is not conducive to improving the tensile strength of the steel wire. If the percentage of manganese in the total mass of the steel wire is higher than this range, the resistivity of the steel wire will be relatively large, affecting the electrical conductivity of the aluminum-clad steel wire after subsequent processing.

[0043] The percentage of silicon in the total mass of the steel wire is 0.35%-1.2%. It is understandable that the percentage of silicon in the total mass of the steel wire can be 0.35%, 0.40%, 0.45%, 0.50%, 0.55%, 0.60%, 0.65%, 0.70%, 0.75%, 0.80%, 0.85%, 0.90%, 0.95%, 1.00%, 1.05%, 1.10%, 1.15%, 1.2%, etc.

[0044] In this embodiment, silicon can improve the tensile strength of the steel wire by solid solution strengthening. If the percentage of silicon in the total mass of the steel wire is lower than this range, the solid solution strengthening effect of silicon is weakened, which is not conducive to improving the tensile strength of the steel wire. If the percentage of silicon in the total mass of the steel wire is higher than this range, the resistivity of the steel wire will be relatively large, affecting the conductivity of the aluminum clad steel wire after subsequent processing.

[0045] The percentage of chromium element in the total mass of the steel wire is less than or equal to 0.40%. It is understandable that the percentage of chromium element in the total mass of the steel wire can be 0.10%, 0.20%, 0.30%, 0.40%, etc.

[0046] In this embodiment, the chromium element can improve the tensile strength of the steel wire by reducing the lamellar spacing of pearlite in the steel wire. If the percentage of the chromium element in the total mass of the steel wire is lower than this range, the effect of the chromium element on improving the tensile strength of the steel wire is weakened. If the percentage of the chromium element in the total mass of the steel wire is higher than this range, the resistivity of the steel wire will be relatively large, affecting the electrical conductivity of the aluminum-clad steel wire after subsequent processing.

[0047] S2, hot rolling the steel wire until the steel wire is austenitized, and then using the heat after the hot rolling of the steel wire to perform salt bath quenching on the austenitized steel wire until the steel wire is austenitized.

[0048] In this step, the temperature of the hot rolling treatment of the steel wire is 900-950°C, and the hot rolling treatment time is 1-2 minutes. The hot rolling treatment of the steel wire adopts an online heat treatment method. After the steel wire is hot-rolled at a temperature of 900-950°C for 1-2 minutes, the degree of austenitization of the steel wire can reach at least 98%, thereby improving the strength and toughness of the steel wire, and removing the internal stress of the steel wire, avoiding deformation and other problems during subsequent processing.

[0049] After the steel wire is hot-rolled, it is immediately transferred to a salt bath tank to perform salt bath quenching using the residual heat on the steel wire. The temperature of the steel wire during salt bath quenching is 500-580°C, and the time of salt bath quenching at this temperature is 15-50s, so that the degree of calcite of the steel wire reaches 90%. This improves the toughness and ductility of the steel wire and reduces the stress concentration of the steel wire. In this way, by controlling the temperature and time of hot rolling and the temperature and time of salt bath quenching, the processing deformation of the steel wire during subsequent descaling, shape adjustment and drawing can be reduced.

[0050] S3. Remove the oxide scale on the surface of the sorbitized steel wire and adjust the shape of the steel wire.

[0051] In this step, the oxide scale on the surface of the steel wire can be removed by grinding or pickling.

[0052] Wherein, when pickling is adopted, the steel wire can be pickled by industrial hydrochloric acid or sulfuric acid, etc. When grinding is adopted, the steel wire can be grinded by a polishing machine.

[0053] In this step, the cross-sectional shape of the steel wire can be adjusted to a circle by pressing or die drawing, and the diameter deviation is controlled to be no more than 0.05 mm.

[0054] S4. After coating the outer periphery of the steel wire with an aluminum layer 202, a busbar is formed.

[0055] In this step, a layer of aluminum material can be evenly covered on the outer periphery of the steel wire by a continuous extrusion coating machine. Specifically, the heating temperature of the die cavity of the extrusion coating machine is higher than 400°C, and the aluminum rod is heated to a semi-molten state in the die cavity and then composited with the steel wire, and then the steel wire and the aluminum layer 20 are synchronously extruded from the die hole to form a busbar.

[0056] S5. Pull out the busbar.

[0057] In this step, the dies used for drawing the busbar are a pressure die and a tungsten steel wire drawing die. The pressure die and the tungsten steel wire drawing die are combined to form a composite die to draw the busbar, achieving synchronous deformation of the steel wire and the aluminum wire. The drawing speed of the busbar is 4-8m / s.

[0058] It can be understood that, in other embodiments, the mold used for drawing the busbar may also be other molds that can achieve synchronous deformation of the steel wire and the aluminum wire.

[0059] In this step, when the busbar is drawn, the busbar needs to be drawn multiple times, and the total compression rate of the busbar is controlled to be less than or equal to 80%. The number of times the busbar is drawn multiple times is less than or equal to 9 times.

[0060] The existing aluminum-clad steel wire production process requires that the total compression rate of the busbar be controlled at 88% or above to meet the tensile strength requirements of G5A-grade aluminum-clad steel wire. Based on the average compression rate of the busbar cannot be higher than 17%, this total compression rate design of 88% or above requires at least 12 drawing passes. However, the existing aluminum-clad steel wire drawing machine can only perform 9 consecutive drawing passes at most, resulting in two drawing passes to achieve a total compression rate of 88% or above, which not only increases production costs but also reduces production efficiency.

[0061] The present application controls the total compression rate of the busbar to be less than or equal to 80%. The busbar only needs to be drawn a maximum of 9 times, which does not exceed the maximum number of drawing times of the existing aluminum-clad steel wire drawing machine. Therefore, the busbar only needs to be drawn once, thereby reducing the production cost of the aluminum-clad steel wire and improving production efficiency.

[0062] At the same time, the present application adds carbon, manganese, silicon and chromium to the steel wire and controls the addition ratio of each element to make the steel wire have excellent tensile strength, so that while controlling the total compression rate of the busbar to be less than or equal to 80%, the prepared aluminum-clad steel wire can also meet the tensile strength requirements of G5A-grade aluminum-clad steel wire.

[0063] In summary, the embodiment of the present application provides a method 100 for preparing a high-strength aluminum-clad steel wire. After the steel wire is hot-rolled to austenitize it, the remaining heat after the hot-rolling treatment of the steel wire is directly used to perform a salt bath quenching treatment on it, so that the austenitized steel wire is austenitized, so that the steel wire can be continuously heated online in the same production workshop. Only a single continuous heating of the steel wire is required to make the performance of the steel wire meet actual needs, avoiding multiple heating of the steel wire, thereby reducing production costs and improving production efficiency. In addition, the present application only performs a single drawing treatment on the steel wire, and the steel wire is drawn after the salt bath quenching treatment is completed. The structural strength of the steel wire can be improved through the salt bath quenching treatment, and the processing deformation of the steel wire during the subsequent descaling, shape adjustment and drawing treatment can be reduced, thereby ensuring that the finally prepared aluminum-clad steel wire has better tensile strength and plastic toughness and other properties.

[0064] Among them, the preparation method 100 of the high-strength aluminum-clad steel wire of the present application can complete the hot rolling treatment and salt bath quenching treatment of the steel wire through online heat treatment in the steel wire production workshop, so that the steel wire has completed the sorbitization treatment when leaving the steel plant. When the steel wire is transported to the downstream aluminum-clad steel wire production workshop, there is no need to heat treat the steel wire to make it austenitized and sorbitized, avoiding the steel wire in the downstream aluminum-clad steel wire production workshop. Secondary heating, thereby reducing energy consumption in the steel wire production process and reducing the production cost of the steel wire.

[0065] like Figure 2 See Figure 1 This embodiment also provides a high-strength aluminum-clad steel wire 200, which is prepared by the above-mentioned high-strength aluminum-clad steel wire preparation method 100. The high-strength aluminum-clad steel wire 200 includes a steel core layer 201 and an aluminum layer 202 coated on the outer peripheral surface of the steel core layer 201. The steel core layer 201 is the steel wire processed by the above-mentioned high-strength aluminum-clad steel wire preparation method 100.

[0066] When processing aluminum-clad steel wire, the present application improves the conductivity of the steel core layer 201 by increasing the cross-sectional area of ​​the aluminum layer 202 by approximately 0.4%-0.8% compared to the existing aluminum-clad steel wire.

[0067] In one embodiment, the high-strength aluminum-clad steel wire 200 is of LB14 type, the cross-sectional proportion of the steel core layer 201 is 86%-86.6% compared to the cross-sectional proportion of the aluminum-clad steel wire, and the cross-sectional proportion of the aluminum layer 202 is 13.4-14% compared to the cross-sectional proportion of the aluminum-clad steel wire. In the existing LB14 type aluminum-clad steel wire, the cross-sectional proportion of the steel core layer 201 is 86.5%-87% compared to the cross-sectional proportion of the aluminum-clad steel wire, and the cross-sectional proportion of the aluminum layer 202 is 13%-13.5% compared to the cross-sectional proportion of the aluminum-clad steel wire. Compared to the existing LB14 type aluminum-clad steel wire, the aluminum-clad steel wire of the present application can reduce the cross-sectional proportion of the steel core layer 201 by increasing the cross-sectional proportion of the aluminum layer 202, thereby improving the electrical conductivity of the aluminum-clad steel wire and solving the problem of adjusting the content of the Mn element and the Si element in the steel wire to affect the electrical conductivity of the steel core layer 201.

[0068] In one embodiment, the high-strength aluminum-clad steel wire 200 is of LB20 type, the cross-sectional proportion of the steel core layer 201 is 73.8%-74.5% of that of the aluminum-clad steel wire, and the cross-sectional proportion of the aluminum layer 202 is 25.5-26.2% of that of the aluminum-clad steel wire. In the existing LB20 type aluminum-clad steel wire, the cross-sectional proportion of the steel core layer 201 is 74.6%-75% of that of the aluminum-clad steel wire, and the cross-sectional proportion of the aluminum layer 202 is 25%-25.4% of that of the aluminum-clad steel wire. Compared with the existing LB20 type aluminum-clad steel wire, the aluminum-clad steel wire of the present application can reduce the cross-sectional proportion of the steel core layer 201 by increasing the cross-sectional proportion of the aluminum layer 202, thereby improving the electrical conductivity of the aluminum-clad steel wire and solving the problem of adjusting the content of the Mn and Si elements in the steel wire to affect the electrical conductivity of the steel core layer 201.

[0069] Example 1

[0070] A steel wire is prepared, wherein the carbon element, the manganese element, the silicon element, and the chromium element in the steel wire account for 0.87%, 0.79%, 0.97%, and 0.22% of the total mass of the steel wire, respectively.

[0071] Subsequently, the steel wire was hot rolled at 920°C for 70 seconds to austenitize the steel wire to 98%. After the hot rolling, the steel wire was immediately transferred to a salt bath tank to perform salt bath quenching using the residual heat in the steel wire, and the steel wire was treated at 520°C for 35 seconds to austenitize the steel wire to 90%.

[0072] Subsequently, the steel wire is pickled with industrial hydrochloric acid to remove the oxide scale on the surface of the steel wire, and then the shape of the steel wire is adjusted to a round shape.

[0073] Finally, a layer of aluminum is evenly covered on the outer periphery of the steel wire through a continuous extrusion coating machine, and then the busbar is drawn at a speed of 6m / s by combining a pressure die and a tungsten steel drawing die to form a composite die. During the drawing process, the total compression rate of the busbar is controlled to be 80%, and the number of times the busbar is drawn is 9 times.

[0074] In this embodiment, taking the processing of LB20 aluminum-clad steel wire as an example, the cross-sectional area of ​​the steel core layer 201 is 74% of the aluminum-clad steel wire, and the cross-sectional area of ​​the aluminum layer 202 is 26% of the aluminum-clad steel wire. This type of aluminum-clad steel wire has been tested, and its strength is 1745MPa, the elongation at break is 1.2%, and the torsion is 38 turns. The conductivity of the steel core layer 201 is 6.5%, and the overall conductivity is 21%.

[0075] Comparative Example 1

[0076] A steel wire is prepared, wherein the carbon element, the manganese element, the silicon element, and the chromium element in the steel wire account for 0.87%, 0.79%, 0.97%, and 0.22% of the total mass of the steel wire, respectively.

[0077] Subsequently, the steel wire was hot rolled at 920°C for 70 seconds to austenitize the steel wire to 98%. After the hot rolling, the steel wire was immediately transferred to a salt bath tank to perform salt bath quenching using the residual heat in the steel wire, and the steel wire was treated at 520°C for 35 seconds to austenitize the steel wire to 90%.

[0078] Subsequently, the steel wire is pickled with industrial hydrochloric acid to remove the oxide scale on the surface of the steel wire, and then the shape of the steel wire is adjusted to a round shape.

[0079] Finally, a layer of aluminum is evenly covered on the outer periphery of the steel wire through a continuous extrusion coating machine, and then the busbar is drawn at a speed of 6m / s by combining a pressure die and a tungsten steel drawing die to form a composite die. During the drawing process, the total compression rate of the busbar is controlled to be 80%, and the number of times the busbar is drawn is 9 times.

[0080] In this embodiment, taking the processing of LB20 aluminum-clad steel wire as an example, the cross-sectional area of ​​the steel core layer 201 is 75.2% of that of the aluminum-clad steel wire, and the cross-sectional area of ​​the aluminum layer 202 is 24.8% of that of the aluminum-clad steel wire. This type of aluminum-clad steel wire has been tested, and its strength is 1760MPa, its elongation at break is 1.2%, and it is twisted 36 times. The conductivity of the steel core layer 201 is 6.5%, and the overall conductivity is 19.8%, which is unqualified.

[0081] Comparative Example 2

[0082] A steel wire is prepared, in which the percentages of carbon, manganese, silicon, and chromium in the steel wire to the total mass of the steel wire are 0.94%, 0.51%, 0.23%, and 0.12%, respectively.

[0083] Subsequently, the steel wire was hot rolled at 920°C for 70 seconds to austenitize the steel wire to 98%. After the hot rolling, the steel wire was immediately transferred to a salt bath tank to perform salt bath quenching using the residual heat in the steel wire, and the steel wire was treated at 520°C for 35 seconds to austenitize the steel wire to 90%.

[0084] Subsequently, the steel wire is pickled with industrial hydrochloric acid to remove the oxide scale on the surface of the steel wire, and then the shape of the steel wire is adjusted to a round shape.

[0085] Finally, a layer of aluminum is evenly covered on the outer periphery of the steel wire through a continuous extrusion coating machine, and then the busbar is drawn at a speed of 6m / s by combining a pressure die and a tungsten steel drawing die to form a composite die. During the drawing process, the total compression rate of the busbar is controlled to be 80%, and the number of times the busbar is drawn is 9 times.

[0086] In this embodiment, taking the processing of LB20 aluminum-clad steel wire as an example, the cross-sectional area of ​​the steel core layer 201 is 74% of that of the aluminum-clad steel wire, and the cross-sectional area of ​​the aluminum layer 202 is 26% of that of the aluminum-clad steel wire. This type of aluminum-clad steel wire has been tested, and its strength is 1726MPa, its elongation at break is 0.8%, and after 17 turns of twisting, the conductivity of the steel core layer 201 is 8.2%, and the overall conductivity is 21.7%. When the carbon content increases to more than 0.94%, and after passing the 80% compression rate bimetallic drawing, the plasticity of the material decreases, and the elongation and torsion indicators are unqualified.

[0087] Comparative Example 3

[0088] A steel wire is prepared, wherein the carbon element, the manganese element, the silicon element, and the chromium element in the steel wire account for 0.87%, 0.79%, 0.97%, and 0.22% of the total mass of the steel wire, respectively.

[0089] Subsequently, the steel wire was hot rolled at 850° C. for 70 seconds. After the hot rolling, the steel wire was immediately transferred to a salt bath tank for salt bath quenching using the residual heat in the steel wire, and the steel wire was treated at 480° C. for 35 seconds.

[0090] Subsequently, the steel wire is pickled with industrial hydrochloric acid to remove the oxide scale on the surface of the steel wire, and then the shape of the steel wire is adjusted to a round shape.

[0091] Finally, a layer of aluminum is evenly covered on the outer periphery of the steel wire through a continuous extrusion coating machine, and then the busbar is drawn at a speed of 6m / s by combining a pressure die and a tungsten steel drawing die to form a composite die. During the drawing process, the total compression rate of the busbar is controlled to be 80%, and the number of times the busbar is drawn is 9 times.

[0092] In this embodiment, since the 480°C salt bath temperature is too low and enters the bainite transformation range, the steel core microstructure shows abnormal bainite brittle structure, and the wire breaks frequently during the aluminum-clad drawing process, making it impossible to produce. Taking the processing of LB20 aluminum-clad steel wire as an example, the cross-section of the steel core layer 201 accounts for 74% of the aluminum-clad steel wire, and the cross-section of the aluminum layer 202 accounts for 26% of the aluminum-clad steel wire. This type of aluminum-clad steel wire has been tested, and its strength is 1696MPa, the elongation at break is 0.6%, and after 5 turns of twisting, the conductivity of the steel core layer 201 is 6.5%, and the overall conductivity is 21%. The rolling heating temperature is 850°C, the salt bath temperature is 480°C, and the steel core shows abnormal bainite structure, the wire breaks frequently, and the elongation and twisting indicators are unqualified.

[0093] In the above, the specific embodiments of the present application are described with reference to the accompanying drawings. However, those skilled in the art will appreciate that various changes and substitutions may be made to the specific embodiments of the present application without departing from the scope of the present application. These changes and substitutions are all within the scope defined by the present application.

Claims

1. A method for preparing high-strength aluminum-clad steel wire, It is characterized in that The steps include: Prepare a steel wire, the steel wire comprising carbon, manganese, silicon, and chromium, wherein the carbon element accounts for 0.85%-0.90% of the total mass of the steel wire, the manganese element accounts for 0.60%-0.90% of the total mass of the steel wire, the silicon element accounts for 0.35%-1.2% of the total mass of the steel wire, and the chromium element accounts for less than or equal to 0.40% of the total mass of the steel wire; Hot rolling the steel wire until the steel wire is austenitized, and then using the heat from the hot rolling of the steel wire to perform salt bath quenching on the austenitized steel wire until the steel wire is austenitized; removing the oxide scale on the surface of the steel wire after being subjected to sorbitization, and then adjusting the shape of the steel wire; After coating the outer circumference of the steel wire with an aluminum layer, a busbar is formed; The busbar is subjected to a drawing process.

2. The method for preparing the high-strength aluminum-clad steel wire according to claim 1, It is characterized in that When the busbar is subjected to a drawing process, the busbar is subjected to a multi-pass drawing process, and the total compression rate of the busbar is controlled to be less than or equal to 80%.

3. The method for preparing the high-strength aluminum-clad steel wire according to claim 2, It is characterized in that The number of times the busbar is drawn in multiple passes is less than or equal to 9 times.

4. The method for preparing the high-strength aluminum-clad steel wire according to claim 1, It is characterized in that The drawing speed of the busbar is 4-8 m / s.

5. The method for preparing the high-strength aluminum-clad steel wire according to claim 1, It is characterized in that The temperature of the hot rolling treatment of the steel wire is 900-950° C., and the hot rolling treatment time is 1-2 minutes.

6. The method for preparing the high-strength aluminum-clad steel wire according to claim 1, It is characterized in that The temperature of the steel wire during salt bath quenching treatment is 500-580° C., and the time of the salt bath quenching treatment is 15-50 seconds.

7. The method for preparing the high-strength aluminum-clad steel wire according to claim 1, It is characterized in that The degree of austenitization of the steel wire reaches 98%, and the degree of forestitization of the steel wire reaches 90%.

8. The method for preparing the high-strength aluminum-clad steel wire according to claim 1, It is characterized in that The dies used for drawing the busbar are a pressure die and a tungsten steel wire drawing die.

9. A high-strength aluminum-clad steel wire, It is characterized in that The high-strength aluminum-clad steel wire is prepared by the preparation method of the high-strength aluminum-clad steel wire as described in any one of claims 1 to 8.

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