Composite steel cord suitable for drawing high strength specific mass steel cord and method of manufacture

Abstract

This invention discloses a composite steel wire suitable for drawing high-strength, high-performance composite steel cord and its preparation method. The method involves removing the oxide scale from high-carbon equivalent cord steel wire rods and then drawing them to obtain steel wires of the desired diameter. A low-carbon equivalent cord steel tube with the same inner diameter as the outer diameter of the drawn high-carbon equivalent steel wire is selected, and the oxide scale on both the inner and outer surfaces of the tube is removed. The high-carbon equivalent steel wire is threaded into the low-carbon equivalent steel tube, and a large-to-medium drawing process is performed on the composite steel with a high-carbon equivalent core and a low-carbon equivalent outer layer to form the composite steel wire. The composite steel wire undergoes austenitization, isothermal quenching, and copper and zinc plating. The brass-plated composite steel wire is then wet-drawn to finally form a high-strength, high-performance composite steel wire. In this invention, the core, which has a lower deformation during the drawing process, uses steel with a higher carbon equivalent content than the outer layer. The high-carbon steel wire in the core is nested with a high-carbon steel tube with a lower carbon equivalent content than the core, and the composite steel wire is drawn to produce a composite steel wire capable of producing high-strength, high-performance composite steel wire.

Description

Technical Field

[0001] This invention relates to the field of composite metal materials technology, and in particular to a composite steel wire suitable for drawing high-strength plastic-coated steel cord and its preparation method. Background Technology

[0002] With increasing focus on environmental protection and the rapid development of new energy vehicles, there are growing demands for lightweight and high-strength-ductility steel cords, which form the skeleton of automobile tires. During wet drawing, the surface of the steel wire deforms more than the core; the core primarily affects strength, while the surface mainly affects ductility. However, current high-carbon steel wires exhibit a sharp decrease in ductility and accelerated age hardening during the drawing process to produce high-strength, fine-diameter wires. To meet energy and environmental protection requirements and produce high-strength-ductility high-carbon steel wires, a suitable busbar for drawing high-strength-ductility steel cords is urgently needed. Summary of the Invention

[0003] The purpose of this invention is to provide a composite steel wire suitable for drawing high-strength plastic-coated steel cord and a method for its preparation. In order to improve the plasticity of the steel wire, the core with a lower deformation during the drawing process is made of steel with a higher carbon equivalent content than the surface layer. Based on this, the high-carbon steel wire in the core is nested with a high-carbon steel tube with a lower carbon equivalent content than the core, and then drawn to prepare a composite steel wire capable of drawing high-strength plastic-coated steel cord, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A composite steel wire suitable for drawing high-strength plastic-coated steel cord and its preparation method, comprising the following steps: Step 1: Remove the oxide scale from the high carbon equivalent cord steel wire rod and lubricate the surface with lubricating powder. Then, draw the wire to the required diameter through medium and large drawing processes.

[0005] Step 2: Select a low-carbon equivalent cord steel pipe with the same inner diameter as the outer diameter of the high-carbon equivalent steel wire drawn in Step 1, and remove the oxide scale from the inner and outer surfaces of the steel pipe.

[0006] Step 3: Insert high-carbon equivalent steel wire into a low-carbon equivalent steel tube, and perform large and medium drawing processes on the composite steel with a high-carbon equivalent core and a low-carbon equivalent outer layer to form a composite steel wire.

[0007] Step 4: The composite steel wire is subjected to austenitization treatment, isothermal quenching treatment, and copper and zinc plating treatment to finally form brass-plated composite steel wire.

[0008] Step 5: The brass-plated composite steel wire is wet-drawn. After multiple drawing passes, a high-strength, high-ductility composite steel wire is finally formed.

[0009] A further improvement of the present invention is that the oxide scale removal treatment on the steel wire surface in step 1 and the oxide scale removal treatment in step 2 adopt a dephosphorization + pickling and water washing and drying process, and the concentration of hydrochloric acid for pickling is WL: 180±30g / L.

[0010] A further improvement of the present invention is that the large-scale pulling in step 2 is performed by applying borax and soap powder.

[0011] A further improvement of the present invention is that step 4 involves austenitizing treatment at a temperature of 920℃-950℃ and a lead bath temperature of 550-600℃.

[0012] A further improvement of the present invention is that, in step 5, the wet drawing process uses a suspension emulsion as the lubricating medium.

[0013] A further improvement of the present invention is that the number of wet drawing passes in step 5 is 23.

[0014] A further improvement of the present invention is the high-strength plastic composite steel wire formed in step 5.

[0015] The beneficial effects of this invention are: This invention relates to a composite steel wire and its preparation method suitable for drawing high-strength plastic-coated steel cords. Based on the principle that the surface deformation of steel wire is relatively larger than that of the core during wet drawing, and that the core mainly affects strength while the surface mainly affects plasticity, this invention designs a composite steel wire with a high core carbon equivalent and a low outer carbon equivalent through a rational design and gradient change of the internal carbon equivalent. Simultaneously, the austenitization process promotes carbon atom diffusion at the core-outer interface, achieving a better transition from high to low carbon equivalent. The composite steel wire designed in this invention can reduce deformation resistance during wet drawing, reduce heat accumulation, and reduce the risk of defect generation or propagation, further improving the surface quality and plasticity of the steel wire, ultimately producing a high-strength, high-plasticity steel wire. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process for developing the composite steel wire of this invention.

[0017] Figure 2 This is a schematic diagram comparing the strength and plasticity of steel wire drawn from conventional steel wire busbars and composite steel wire busbars of the present invention in Example 1.

[0018] Figure 3 This is a schematic diagram comparing the strength and plasticity of steel wires drawn from conventional steel wire busbars and composite steel wire busbars of the present invention in Example 2.

[0019] Figure 4 This is a schematic diagram comparing the strength and plasticity of steel wires drawn from conventional steel wire busbars and composite steel wire busbars of the present invention in Example 3. Detailed Implementation

[0020] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0021] ①. High carbon equivalent cord steel is subjected to mechanical peeling, pickling, and water washing and drying in sequence. Then, it is dry-drawn by applying boric acid and soap powder to obtain steel wire of the required diameter.

[0022] ②. Select a low-carbon equivalent cord steel pipe with the same inner diameter as the outer diameter of the high-carbon equivalent steel wire drawn in ①. Remove oxide scale from the inner and outer surfaces of the steel pipe, and perform pickling, water washing and drying treatment.

[0023] ③. The high-carbon equivalent steel wire drawn in ① is threaded into a low-carbon equivalent steel pipe. After performing large and medium drawing processes on the composite steel with a high-carbon equivalent core and a low-carbon equivalent outer layer, a composite steel wire is formed.

[0024] ④. The composite steel wire is subjected to austenitizing treatment, isothermal quenching treatment, and copper and zinc plating treatment to finally form brass-plated composite steel wire.

[0025] ⑤. The brass-plated composite steel wire is wet-drawn, and after multiple drawing passes, a high-strength and high-ductility composite steel wire is finally formed.

[0026] This composite steel wire can reduce the deformation resistance during the drawing process and is easy to draw.

[0027] This composite steel wire can reduce the heat of accumulation during the drawing process, improve plasticity, and reduce the generation or propagation of defects.

[0028] This composite steel wire can balance the plasticity and strength of the drawn product, producing high-strength, high-performance steel wire. Example 1

[0029] ①. 97C cord steel wire rod with a diameter of 5.5mm is sequentially passed through a mechanical peeling device, an acid pickling and washing air blowing device, and a borax lubrication device, and cold-drawn in 5-6 passes to a high-carbon steel wire with a diameter of 2.5mm. The drawing speed is controlled at 100m / min.

[0030] ②. Select 92C cord steel pipe with an inner diameter of 2.5mm and an outer diameter of 5.5mm for pickling and washing, and dry. The concentration of hydrochloric acid for pickling is WL: 180±30g / L.

[0031] ③. A 2.5mm thick 97C cord steel wire is threaded into a 92C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm. It is then sequentially passed through a mechanical peeling device, a pickling and washing device, an air blowing device, and a borax lubrication device, undergoing six cold draws to obtain a high-carbon steel wire with a diameter of 1.48mm. The drawing speed is controlled at 100m / min. This forms a composite steel wire.

[0032] ④. The composite steel wire is subjected to austenitization treatment at a temperature of 920℃-950℃, isothermal quenching treatment at a temperature of 550℃-600℃, and copper and zinc plating treatment, finally forming a composite steel wire with a brass-plated surface.

[0033] ⑤. The brass-plated composite steel wire is subjected to wet drawing, with 23 drawing passes at a speed of 4 m / s, ultimately forming a 0.22 mm MT grade high-strength, high-ductility composite steel wire. Its strength and ductility performance are as follows: Figure 2 As shown. Example 2

[0034] ①. 92C cord steel wire rod with a diameter of 5.5mm is sequentially passed through a mechanical peeling device, an acid pickling and washing air blowing device, and a borax lubrication device, and cold-drawn in 5-6 passes to a high-carbon steel wire with a diameter of 2.5mm. The drawing speed is controlled at 100m / min.

[0035] ②. Select 86C cord steel pipes with an inner diameter of 2.5mm and an outer diameter of 5.5mm for pickling and washing, and then dry. The concentration of hydrochloric acid for pickling is WL: 180±30g / L.

[0036] ③. A 2.5mm thick 92C cord steel wire is threaded into an 86C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm. It is then sequentially passed through a mechanical peeling device, a pickling and washing device, an air-blowing device, and a borax lubrication device, undergoing six cold draws to obtain a high-carbon steel wire with a diameter of 1.48mm. The drawing speed is controlled at 100m / min. This forms a composite steel wire.

[0037] ④. The composite steel wire is subjected to austenitization treatment at a temperature of 920℃-950℃, isothermal quenching treatment at a temperature of 550℃-600℃, and copper and zinc plating treatment, finally forming a composite steel wire with a brass-plated surface.

[0038] ⑤. The brass-plated composite steel wire is subjected to wet drawing, with 23 drawing passes at a speed of 6 m / s, ultimately forming a 0.22 mm UT-grade high-strength, high-ductility composite steel wire. Its strength and ductility performance are as follows: Figure 3 As shown. Example 3

[0039] ①. 86C cord steel wire rod with a diameter of 5.5mm is sequentially passed through a mechanical peeling device, a pickling and washing device, an air blowing device, and a borax lubrication device, and cold-drawn in 5-6 passes to a high-carbon steel wire with a diameter of 2.5mm. The drawing speed is controlled at 100m / min.

[0040] ②. Select 82C cord steel pipe with an inner diameter of 2.5mm and an outer diameter of 5.5mm for pickling and washing, and then dry. The concentration of hydrochloric acid for pickling is WL: 180±30g / L.

[0041] ③. 2.5mm thick 86C cord steel wire is threaded into an 82C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm. It is then sequentially passed through a mechanical peeling device, a pickling and washing device, an air blowing device, and a borax lubrication device, undergoing six cold draws to obtain a high-carbon steel wire with a diameter of 1.48mm. The drawing speed is controlled at 100m / min. This forms a composite steel wire.

[0042] ④. The composite steel wire is subjected to austenitization treatment at a temperature of 920℃-950℃, isothermal quenching treatment at a temperature of 550℃-600℃, and copper and zinc plating treatment, finally forming a composite steel wire with a brass-plated surface.

[0043] ⑤. The brass-plated composite steel wire is subjected to wet drawing, with 23 drawing passes at a speed of 10 m / s, ultimately forming a 0.22 mm thick ST-grade high-strength, high-ductility composite steel wire. Its strength and ductility performance are as follows: Figure 4 As shown.

[0044] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing composite steel wire suitable for drawing high-strength plastic-coated steel cord, characterized in that... Includes the following steps: Step 1: Remove the oxide scale from the high carbon equivalent cord steel wire rod and lubricate the surface with lubricating powder. Then, draw the wire to the required diameter through medium and large drawing. Step 2: Select a low-carbon equivalent cord steel pipe with the same inner diameter as the outer diameter of the high-carbon equivalent steel wire drawn in Step 1, and remove the oxide scale from the inner and outer surfaces of the steel pipe. Step 3: Thread the high carbon equivalent steel wire into the low carbon equivalent steel tube, and perform a large and medium drawing process on the composite steel with a high carbon equivalent core and a low carbon equivalent outer layer to form a composite steel wire. Step 4: The composite steel wire is subjected to austenitization treatment, isothermal quenching treatment, and copper and zinc plating treatment to finally form brass-plated composite steel wire. Step 5: The brass-plated composite steel wire is wet-drawn. After multiple drawing passes, a high-strength, high-ductility composite steel wire is finally formed.

2. The method for preparing composite steel wire suitable for drawing high-strength plastic-coated steel cord as described in claim 1, characterized in that: The oxide scale removal process in step 1 and step 2 involves dephosphorization, pickling, and water washing and drying. The concentration of hydrochloric acid used for pickling is WL: 180±30g / L.

3. The method for preparing composite steel wire suitable for drawing high-strength plastic-coated steel cord as described in claim 1, characterized in that: Step 2, the large-scale pulling process, employs a method of applying borax and soap powder during the pulling process.

4. The method for preparing composite steel wire suitable for drawing high-strength plastic-coated steel cord as described in claim 1, characterized in that: Step 4 involves austenitizing treatment at a temperature of 920℃-950℃ and a lead bath temperature of 550-600℃.

5. The method for preparing composite steel wire suitable for drawing high-strength plastic-coated steel cord as described in claim 1, characterized in that: In step 5, the wet drawing process uses a suspension emulsion as the lubricating medium.

6. The method for preparing a composite steel wire suitable for drawing high-strength plastic-coated steel cord as described in claim 1, characterized in that: In step 5, the number of wet drawing passes is 23.

7. A composite steel wire suitable for drawing high-strength plastic-coated steel cord, characterized in that: It is made using the method for preparing composite steel wire suitable for drawing high-strength plastic-coated steel cord as described in any one of claims 1-6.

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