Composite steel wire suitable for drawing steel cord with high product of strength and elongation and preparation method of composite steel wire

Abstract

The invention discloses a composite steel wire suitable for drawing a steel cord with high product of strength and elongation and a preparation method of the composite steel wire. Oxide skin removal treatment is carried out on a high-carbon equivalent cord steel wire rod, and then a steel wire with the required wire diameter is obtained through drawing. And selecting a low-carbon equivalent cord steel pipe with the inner diameter being the same as the outer diameter of the drawn high-carbon equivalent steel wire, and carrying out oxide skin removal treatment on the surfaces of the inner wall and the outer wall of the steel pipe. Penetrating the high-carbon-equivalent steel wire into the low-carbon-equivalent steel pipe, and performing large-medium drawing on the composite steel with the high-carbon-equivalent core part and the low-carbon-equivalent outer layer to form a composite steel wire; carrying out austenitizing treatment, isothermal quenching treatment and copper and zinc plating treatment on the composite steel wire; and wet drawing is conducted on the brass-plated composite steel wire, and finally the composite steel wire with the high product of strength and ductility is formed. In the drawing process, a core part with lower deformation adopts carbon equivalent component steel higher than that of a surface layer, a core part high-carbon steel wire and a high-carbon steel pipe with the carbon equivalent lower than that of the core part are nested, and the composite steel wire capable of drawing the steel wire with the high product of strength and elongation is prepared through drawing.

Description

Technical Field

[0001] The invention relates to the technical field of metal material composites, and in particular to a composite steel wire suitable for drawing high-strength plastic-accumulated steel cords and a preparation method thereof. Background Art

[0002] With the increasing attention paid to environmental protection and the rapid development of new energy vehicles, the steel cords used as the skeleton of automobile tires have been required to be lightweight and have high strength and plasticity. The surface deformation of the steel wire is larger than the core deformation during wet drawing. The core mainly affects the strength, while the surface mainly affects the plasticity. However, the current high-carbon steel wire shows a sharp decrease in plasticity and accelerated aging hardening during the process of drawing high-strength and thin wire diameter. In order to meet the needs of energy and environmental protection, a high-carbon steel wire with high strength and plasticity is prepared. A busbar suitable for drawing high-strength and plasticity steel cord is urgently needed. Summary of the invention

[0003] The object of the present invention is to provide a composite steel wire suitable for drawing high-strength and plastic-product steel cord and a preparation method. In order to improve the plasticity of the steel wire, the core portion with lower deformation during the drawing process adopts steel with a higher carbon equivalent component than the surface layer. Based on this, the high-carbon steel wire of the core is nested with a high-carbon steel tube with a carbon equivalent lower than the core, and drawn into a composite steel wire capable of drawing high-strength and plastic-product steel wire, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions: A composite steel wire suitable for drawing high-strength plastic-accumulated steel cord and a preparation method thereof, comprising the following steps: Step 1: Descaling the high carbon equivalent cord steel wire rod, lubricating the surface with lubricating powder, and then obtaining the steel wire of the required wire diameter through large and medium drawing; Step 2: Select a low carbon equivalent cord steel pipe with an inner diameter equal to the outer diameter of the high carbon equivalent steel wire drawn in step 1, and remove the oxide scale from the inner and outer wall surfaces of the steel pipe.

[0005] Step 3: insert the high carbon equivalent steel wire into the low carbon equivalent steel pipe, 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: austenitizing, isothermal quenching, copper plating and galvanizing the composite steel wire to finally form a brass-plated composite steel wire; Step 5: The brass-plated composite steel wire is wet-drawn, and after multiple drawing passes, a composite steel wire with high strength and plasticity is finally formed.

[0006] A further improvement of the present invention is that the batch treatment for removing oxidation from the steel wire surface in step 1 and the treatment for removing oxide scale in step 2 adopt a phosphorus removal + pickling and water washing and drying process, and the pickling hydrochloric acid concentration is WL: 180±30g / L.

[0007] A further improvement of the present invention is that the large and medium drawing in step 2 is performed by borax coating + soap powder drawing.

[0008] A further improvement of the present invention is that step 4 adopts austenitizing treatment at a temperature of 920°C-950°C and a lead bath temperature of 550-600°C.

[0009] A further improvement of the present invention is that in the wet drawing in step 5, the lubricating medium is a suspension emulsion.

[0010] A further improvement of the present invention is that the number of wet drawing passes in step 5 is 23.

[0011] A further improvement of the present invention is that the high-strength and high-plastic composite steel wire is formed in step 5.

[0012] Beneficial effects of the present invention: The composite steel wire and preparation method suitable for drawing high-strength plastic steel cord of the present invention are based on the principle that the surface deformation of the steel wire is larger than the core deformation during wet drawing, the core mainly affects the strength, and the surface mainly affects the plasticity. Through the reasonable design and gradient change of the internal carbon equivalent, the invention designs a composite steel busbar with high core carbon equivalent and low external carbon equivalent. At the same time, the austenitization process promotes the diffusion of carbon atoms at the junction of the core and the outside, achieving a better transition from high to low carbon equivalent. The composite steel wire designed by the present invention can reduce deformation resistance, reduce accumulation heat and reduce the risk of defect generation or expansion during wet drawing, further improve the surface quality and plasticity of the steel wire, and finally draw a steel wire with high strength and high plasticity. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the process of inventing the composite steel wire of the present invention.

[0014] Figure 2 Schematic diagram comparing the strength-ductility performance of steel wires drawn from the conventional steel wire busbar in Example 1 and the composite steel wire busbar of the present invention.

[0015] Figure 3 Schematic diagram comparing the strength-ductility performance of steel wires drawn from the conventional steel wire busbar in Example 2 and the composite steel wire busbar of the present invention.

[0016] Figure 4 Schematic diagram comparing the strength-ductility performance of steel wires drawn from the conventional steel wire busbar in Example 3 and the composite steel wire busbar of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0018] ①. Mechanically peel, pickle, wash and dry the high carbon equivalent cord steel in sequence, and then apply boric acid and soap powder to dry-draw the steel wire to obtain the required wire diameter; ②. Select a low carbon equivalent cord steel tube with an inner diameter equal to the outer diameter of the high carbon equivalent steel wire after drawing in ①, remove the oxide scale on the inner and outer wall surfaces of the steel tube, pickle it, and wash and dry it with water.

[0019] ③. The high carbon equivalent steel wire drawn in step ① is inserted into the low carbon equivalent steel pipe, and the composite steel with a high carbon equivalent core and a low carbon equivalent outer layer is subjected to a large and medium drawing process to form a composite steel wire.

[0020] ④. The composite steel wire is subjected to austenitizing treatment, isothermal quenching treatment, copper plating and galvanizing treatment to finally form a brass-plated composite steel wire.

[0021] ⑤. The brass-plated composite steel wire is wet-drawn, and after multiple drawing passes, a composite steel wire with high strength and plasticity is finally formed.

[0022] The composite steel wire can reduce deformation resistance during drawing and is easy to draw.

[0023] The composite steel wire can reduce the accumulated heat during the drawing process, improve the plasticity and reduce the generation or expansion of defects; The composite steel wire can take into account both the plasticity and strength of the drawn product and can be used to draw high-strength and plastic-accumulated steel wire. Example 1

[0024] ①. The 97C cord steel wire rod with a diameter of 5.5mm is passed through the mechanical shelling device, the pickling and water washing and blowing device, and the borax coating and lubrication device in sequence, and then cold-drawn for 5-6 times to a high carbon steel wire with a wire diameter of 2.5mm. The drawing speed is controlled at 100m / min.

[0025] ②. Select 92C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm for pickling and water washing, and then dry. The pickling hydrochloric acid concentration is WL: 180±30g / L.

[0026] ③. Insert the 2.5mm 97C cord steel wire into the 92C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm, and pass through the mechanical shelling device, pickling, water washing and blowing device, borax coating and lubrication device in sequence, and then cold-draw it to a high carbon steel wire with a wire diameter of 1.48mm through 6 passes. The drawing speed is controlled at 100m / min. A composite steel wire is formed.

[0027] ④. The composite steel wire is subjected to austenitizing treatment at a temperature of 920°C-950°C, isothermal quenching treatment at a temperature of 550°C-600°C, and copper and zinc plating treatment, and finally a composite steel wire with a brass-plated surface is formed.

[0028] ⑤. The brass-plated composite steel wire is wet-drawn for 23 passes at a speed of 4 m / s, and finally a 0.22 mm MT grade high strength and plasticity composite steel wire is formed. The strength and plasticity performance is as follows: Figure 2 shown. Example 2

[0029] ①. The 92C cord steel wire rod with a diameter of 5.5mm is passed through the mechanical shelling device, the pickling and water washing and blowing device, and the borax coating and lubrication device in sequence, and then cold-drawn for 5-6 times to a high carbon steel wire with a wire diameter of 2.5mm. The drawing speed is controlled at 100m / min.

[0030] ②. Select 86C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm for pickling and water washing, and then dry. The pickling hydrochloric acid concentration is WL: 180±30g / L.

[0031] ③. Insert the 2.5mm 92C cord steel wire into the 86C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm, and pass through the mechanical shelling device, pickling, water washing and blowing device, borax coating and lubrication device in sequence, and then cold-draw it to a high carbon steel wire with a wire diameter of 1.48mm through 6 passes. The drawing speed is controlled at 100m / min. A composite steel wire is formed.

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

[0033] ⑤. The brass-plated composite steel wire is wet-drawn for 23 passes at a speed of 6 m / s, and finally a 0.22 mm UT grade high-strength and plastic composite steel wire is formed. The strength and plastic performance is as follows: Figure 3 shown. Example 3

[0034] ①. The 86C cord steel wire rod with a diameter of 5.5mm is passed through the mechanical shelling device, the pickling and water washing and blowing device, and the borax coating and lubrication device in sequence, and then cold-drawn for 5-6 times to a high carbon steel wire with a wire diameter of 2.5mm. The drawing speed is controlled at 100m / min.

[0035] ②. Select 82C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm for pickling and water washing, and then dry. The pickling hydrochloric acid concentration is WL: 180±30g / L.

[0036] ③. Insert the 2.5mm 86C cord steel wire into the 82C cord steel tube with an inner diameter of 2.5mm and an outer diameter of 5.5mm, and pass through the mechanical shelling device, pickling, water washing and blowing device, borax coating and lubrication device in sequence, and then cold-draw it to a high carbon steel wire with a wire diameter of 1.48mm through 6 passes. The drawing speed is controlled at 100m / min. A composite steel wire is formed.

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

[0038] ⑤. The brass-plated composite steel wire is wet-drawn for 23 passes at a speed of 10 m / s, and finally a 0.22 mm ST grade high-strength and plastic composite steel wire is formed. The strength and plastic performance is as follows: Figure 4 shown.

[0039] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite steel wire suitable for drawing high-strength plastic steel cord and a preparation method, characterized in that The steps include: Step 1: Descaling the high carbon equivalent cord steel wire rod, lubricating the surface with lubricating powder, and then obtaining the steel wire of the required wire diameter through large and medium drawing; Step 2: Select a low carbon equivalent cord steel pipe with an inner diameter that is the same as the outer diameter of the high carbon equivalent steel wire drawn in step 1, and remove the oxide scale on the inner and outer wall surfaces of the steel pipe; Step 3: insert the high carbon equivalent steel wire into the low carbon equivalent steel pipe, 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: austenitizing, isothermal quenching, copper plating and galvanizing the composite steel wire to finally form a brass-plated composite steel wire; Step 5: The brass-plated composite steel wire is wet-drawn, and after multiple drawing passes, a composite steel wire with high strength and plasticity is finally formed.

2. A composite steel wire suitable for drawing high-strength plastic steel cord and a preparation method as claimed in claim 1, characterized in that: The batch treatment for removing oxidation from the steel wire surface in step 1 and the treatment for removing oxide scale in step 2 adopt a phosphorus removal + pickling and water washing and drying process, and the concentration of pickling hydrochloric acid is WL: 180±30g / L.

3. A composite steel wire suitable for drawing high-strength plastic steel cord and a preparation method as claimed in claim 1, characterized in that: The step 2 of large and medium pulling adopts borax coating + soap powder pulling.

4. A composite steel wire suitable for drawing high-strength plastic steel cord and a preparation method as claimed in claim 1, characterized in that: The step 4 adopts austenitizing treatment at a temperature of 920°C-950°C and a lead bath temperature of 550-600°C.

5. A composite steel wire suitable for drawing high-strength plastic steel cord and a preparation method as claimed in claim 1, characterized in that: In the wet drawing in step 5, the lubricating medium is a suspension emulsion.

6. A composite steel wire suitable for drawing high-strength plastic steel cord and a preparation method as claimed in claim 1, characterized in that: The number of wet drawing passes in step 5 is 23.

7. A composite steel wire suitable for drawing high-strength plastic steel cord and a preparation method as claimed in claim 1, characterized in that: The high-strength and high-plastic composite steel wire formed in step 5.

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