Drawing die suitable for high-strength high-carbon steel wire and machining method

Abstract

The invention discloses a drawing die suitable for a high-strength high-carbon steel wire. The drawing die comprises a die sleeve, and a die core is embedded in the die sleeve; the die sleeve is made of foam steel, and the appearance of the die sleeve is porous foam-shaped; the mold core is made of polycrystalline diamond, a mold hole is formed in the center of the mold core, and the mold hole comprises an inlet area, a working area, a sizing area and an outlet area; the die sleeve is made of No.45 foam steel, the interior of the die sleeve is in a honeycomb hole shape and is distributed in a three-dimensional hole through shape, the hole diameter is 300-500 micrometers, the porosity is 25%-45%, and in the drawing process of the die sleeve, lubricating liquid enters the holes and flows to cool the die sleeve. Compared with the prior art, the die sleeve is made of the foam steel with good heat dissipation performance and strength, the artificial diamond (PCD) with good heat conductivity and high hardness and strength is used as the die core, and therefore a channel from steel wire heat generation to rapid heat dissipation is communicated, and the heat aggregation effect of high-carbon steel wire drawing is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of drawing dies, and in particular to a drawing die and a processing method suitable for high-strength and high-carbon steel wires. Background Art

[0002] High-strength and low-weight tire cords can ensure the required strength of the tire while reducing the amount of steel wire used, thereby reducing tire weight and fuel consumption.

[0003] The existing cord wire drawing technology is wet drawing, which is a high-carbon steel wire plastic deformation processing technology that is carried out by passing the high-carbon steel wire through the drawing die under the condition of lubricating liquid or coolant, and passing through the wire drawing die under the action of a certain drawing force. This technology is usually used on a water tank drawing machine with multi-mode and multi-pass drawing, and is widely used. The main reason for the rapid aging and sharp drop in plasticity of high-carbon steel wire during drawing is the heat accumulation effect and the inability to quickly cool and diffuse the accumulated heat. As the carbon equivalent increases, the heat accumulation effect becomes more obvious. In the process of drawing high-carbon steel wire to prepare higher strength and finer wire diameters, more heat will be generated due to the drawing of higher strength steel wires, and the existing dies are not sufficient to quickly transfer the heat to the lubricating liquid, which is then taken away. Therefore, the plasticity of the steel wire will drop sharply and will be accompanied by a trend of rapid aging hardening, resulting in extremely poor plasticity of the steel wire, leading to high wire breakage and poor cord forming problems during the production process. Summary of the invention

[0004] The object of the present invention is to provide a drawing die and processing method suitable for high-strength high-carbon steel wire, which uses foam steel with good heat dissipation and strength as a die sleeve, and uses artificial diamond (PCD) with good thermal conductivity and high hardness and strength as a die core, thereby penetrating the channel from heat generated by the steel wire to rapid heat dissipation, reducing the heat accumulation effect of high-carbon steel wire drawing, and solving the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A drawing die suitable for high-strength high-carbon steel wire comprises a die sleeve, in which a die core is embedded; the die sleeve is made of foam steel, and the appearance of the die sleeve is porous foam; the die core is made of polycrystalline diamond, and a die hole is arranged at the center of the die core, and the die hole comprises four parts: an inlet area, a working area, a sizing area, and an outlet area.

[0006] A further solution of the present invention is that the die sleeve is 45# foam steel, the internal shape of the die sleeve is a honeycomb pore shape, the pores are distributed in a three-dimensional through-pore shape, the pore size is 300μm to 500μm, the porosity is 25% to 45%, and during the drawing process of the die sleeve, the lubricating liquid enters the pores and flows to cool the die sleeve.

[0007] A further solution of the present invention is that the mold sleeve and the mold core are both cylindrical in shape, and the mold sleeve and the mold core form a cold-insertion interference fit.

[0008] A further solution of the present invention is that the function of the mold core inlet area is to allow high carbon steel wire and lubricating liquid to enter.

[0009] A further solution of the present invention is that the function of the working area is to radially compress the high-carbon steel wire with a lubricating liquid film attached to the surface, so as to deform the high-carbon steel wire.

[0010] A further solution of the present invention is that the function of the sizing zone is to further stabilize the wire diameter of the high carbon steel wire after compression deformation.

[0011] A further solution of the present invention is that the function of the outlet zone is that the lubricating liquid in the zone cools the high carbon steel wire with a stable wire diameter after compression deformation.

[0012] A processing method for a drawing die suitable for high-strength high-carbon steel wire comprises the following steps: Step 1: clean and dry the unpunched mold core, the diameter of the cylindrical mold core is 0.9 mm, the height is 0.9 mm, the grain size is 0.5 μm, and it is placed in liquid nitrogen for cooling for 1 hour; Step 2: Clean the machined die sleeve for standby use. The outer dimensions of the cylindrical die sleeve are 25 mm in diameter and 16 mm in height. Step 3, take out the unperforated mold core cooled in liquid nitrogen, install it into the center of the mold sleeve to ensure concentricity and fix it; Step 4: preheat the unperforated mold core to expand it and generate pre-tightening force on the inner wall of the mold sleeve; Step 5: Laser punch a hole in the middle of the unpunched mold core; Step 6: After drilling, the hole is processed and ground according to the parameters such as the length-short axis ratio, the inlet angle, and the length of the sizing belt; Step 7: Polishing the ground holes; Step 8: Detect the parameters of the mold hole.

[0013] Beneficial effects of the present invention: Compared with the existing molds, the drawing die and processing method of the present invention, which are suitable for high-strength high-carbon steel wire, have a reasonable and simple structure, are easy to manufacture, have a long service life, and have a good cooling effect. The mold can improve the heat dissipation efficiency and significantly reduce the heat accumulation of the mold during the high-carbon steel wire drawing process. It can also reduce the risk of high-carbon steel wire defect generation and microcrack expansion, and achieve the drawing preparation of high-carbon steel wire with high plasticity and high strength, and the surface quality of the steel wire is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the overall axonometric view of the present invention.

[0015] Figure 2 for Figure 1sectional view of .

[0016] Figure 3 1 is a comparison diagram of the plastic torsion performance of the conventional PCD mold in Example 1 and the experimental mold of the present invention.

[0017] Figure 4 1 is a comparison diagram of the plastic torsion performance of the conventional PCD mold in Example 1 and the experimental mold of the present invention.

[0018] In the figure: 1-mold sleeve, 2-mold core, 3-entrance area, 4-working area, 5-sizing area, 6-exit area. DETAILED DESCRIPTION

[0019] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0020] like Figures 1-2 As shown, a drawing die suitable for high-strength high-carbon steel wire includes a die sleeve 1, and a die core 2 is embedded in the die sleeve 1; the die sleeve 1 is made of foam steel, and the appearance of the die sleeve 1 is porous foam; the die core 2 is made of polycrystalline diamond, and a die hole is provided at the center of the die core 2, and the die hole includes four parts: an inlet area 3, a working area 4, a sizing area 5, and an outlet area 6.

[0021] The die sleeve 1 is made of 45# foam steel, and the internal shape of the die sleeve 1 is honeycomb-shaped, distributed in a three-dimensional pore through-shape, with a pore size of 300μm to 500μm and a porosity of 25% to 45%. During the drawing process of the die sleeve 1, the lubricating liquid enters the pores and flows to cool the die sleeve 1.

[0022] The mold sleeve 1 and the mold core 2 are both cylindrical in shape, and the mold sleeve 1 and the mold core 2 form a cold-insertion interference fit.

[0023] The function of the inlet area 3 of the mold core 2 is to allow high carbon steel wire and lubricating liquid to enter.

[0024] The function of the working area 4 is to radially compress the high carbon steel wire with a lubricating liquid film attached to the surface, so as to deform the high carbon steel wire.

[0025] The function of the sizing zone 5 is to further stabilize the wire diameter of the high carbon steel wire after compression deformation.

[0026] The function of the outlet area 6 is that the lubricating liquid in the area cools the high carbon steel wire whose wire diameter is stable after compression deformation.

[0027] A processing method for a drawing die suitable for high-strength high-carbon steel wire comprises the following steps: Step 1, clean and dry the unperforated mold core 2, the cylindrical mold core 2 has a diameter of 0.9 mm, a height of 0.9 mm, and a grain size of 0.5 μm, and is placed in liquid nitrogen for cooling for 1 hour; Step 2: Clean the machined die sleeve 1 for standby use. The outer dimensions of the cylindrical die sleeve 1 are 25 mm in diameter and 16 mm in height. Step 3, take out the unperforated mold core 2 cooled in liquid nitrogen, install it into the center of the mold sleeve 1 to ensure concentricity and fix it; Step 4, preheating the unperforated mold core 2 to expand it and generate a pre-tightening force with the inner wall of the mold sleeve 1; Step 5, laser drilling a hole in the middle of the unpunched mold core 2; Step 6: After drilling, the hole is processed and ground according to the parameters such as the length-short axis ratio, the inlet angle, and the length of the sizing belt; Step 7: Polishing the ground holes; Step 8: Detect the parameters of the mold hole. Example 1

[0028] The 97C steel wire with a wire diameter of 1.44 is drawn to a wire diameter of 0.2 by 23 wet drawing passes, of which the foam steel mold of the present invention is used in the last six passes, and the tungsten steel mold is used in the remaining passes. The strength of the drawn steel wire is 4000Mpa, and the torsion parameters are shown in Table 1. The standard is implemented in accordance with the first part of GB∕T 239.1-2023 unidirectional torsion standard. The torsion performance is as follows Figure 3 shown.

[0029] Example 2

[0030] The 92C steel wire with a wire diameter of 1.48 was drawn to a wire diameter of 0.2 by 23 wet drawing passes, of which the foam steel mold of the present invention was used in the last six passes, and the tungsten steel mold was used in the remaining passes. The strength of the drawn steel wire was 4100Mpa, and the torsion parameters were shown in Table 2. The standard was implemented in accordance with the first part of GB∕T 239.1-2023 unidirectional torsion standard. The torsion performance was as follows: Figure 4 shown.

[0031]

[0032] 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 drawing die suitable for high-strength and high-carbon steel wire, Features: The mold sleeve (1) comprises a mold core (2) embedded in the mold sleeve (1); the mold sleeve (1) is made of foam steel, and the mold sleeve (1) has a porous foam appearance; the mold core (2) is made of polycrystalline diamond, and a mold hole is provided at the center of the mold core (2), and the mold hole comprises four parts: an inlet area (3), a working area (4), a sizing area (5), and an outlet area (6).

2. A drawing die suitable for high-strength high-carbon steel wire as claimed in claim 1, Features: The die sleeve (1) is made of No. 45 foam steel. The internal shape of the die sleeve (1) is a honeycomb pore shape, and the distribution is a three-dimensional pore through-hole shape. The pore diameter is 300 μm to 500 μm, and the porosity is 25% to 45%. During the drawing process of the die sleeve (1), the lubricating liquid enters the pores and flows to cool the die sleeve (1).

3. A drawing die suitable for high-strength high-carbon steel wire as claimed in claim 1, Features: The mold sleeve (1) and the mold core (2) are both cylindrical in shape, and the mold sleeve (1) and the mold core (2) form a cold-insertion interference fit.

4. A drawing die suitable for high-strength high-carbon steel wire as claimed in claim 1, Features: The function of the inlet area (3) of the mold core (2) is to allow high carbon steel wire and lubricating liquid to enter.

5. A drawing die suitable for high-strength high-carbon steel wire as claimed in claim 1, Features: The function of the working area (4) is to radially compress the high-carbon steel wire with a lubricating liquid film attached to the surface, thereby deforming the high-carbon steel wire.

6. A drawing die suitable for high-strength high-carbon steel wire as claimed in claim 1, Features: The function of the sizing zone (5) is to further stabilize the wire diameter of the high carbon steel wire after compression deformation.

7. A drawing die suitable for high-strength high-carbon steel wire as claimed in claim 1, Features: The function of the outlet area (6) is that the lubricating liquid in the area cools the high-carbon steel wire with a stable wire diameter after compression deformation.

8. A method for processing a drawing die for high-strength high-carbon steel wire as claimed in any one of claims 1 to 7, Features The steps include: Step 1, clean and dry the unperforated mold core (2), the cylindrical mold core (2) has a diameter of 0.9 mm, a height of 0.9 mm, and a grain size of 0.5 μm, and is placed in liquid nitrogen for cooling for 1 hour; Step 2, cleaning the machined die sleeve (1) for standby use, the outer dimensions of the cylindrical die sleeve (1) are 25 mm in diameter and 16 mm in height; Step 3, take out the unperforated mold core (2) cooled in liquid nitrogen, install it into the center of the mold sleeve (1) to ensure concentricity and fix it; Step 4, preheating the unperforated mold core (2) to expand it and generate a pre-tightening force on the inner wall of the mold sleeve (1); Step 5, laser drilling a hole in the middle of the un-punched mold core (2); Step 6: After drilling, the hole is processed and ground according to the parameters such as the length-short axis ratio, the inlet angle, and the length of the sizing belt; Step 7: Polishing the ground holes; Step 8: Detect the parameters of the mold hole.

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