A continuous high-speed hot drawing device for metal wire and its process

Abstract

This invention provides a continuous high-speed hot drawing device and process for metal wire, belonging to the field of metal wire plastic processing. The device includes a wire feeding frame, at least one set of hot drawing units, and a winding device. The hot drawing unit includes a guide wheel, a lubricant coating device, a material storage preheating device, a tension adjustment device, and a hot drawing forming device. The material storage preheating device is equipped with a drum storage mechanism and a resistance heating device. The tension adjustment device is located between the material storage preheating device and the hot drawing forming device to detect and stabilize the running tension of the wire in real time. The hot drawing forming device includes a drawing die and a drawing working drum. This invention combines the material storage preheating device and the hot drawing forming device to achieve a "simultaneous feeding, heating, and drawing" mode. By coordinating the wire heating temperature, heating time, hot drawing speed, and material storage amount, it achieves efficient heating and high-speed drawing of metal wire, and is particularly suitable for the preparation of wires from difficult-to-deform materials such as magnesium alloys and titanium alloys.

Description

Technical Field

[0001] This invention relates to the field of metal wire plastic processing technology, specifically a continuous high-speed hot drawing device and process for wires of difficult-to-deform metals such as magnesium alloys and titanium alloys. Background Technology

[0002] Metal wires have a wide range of applications, such as welding wires, fasteners like rivets and bolts used in aerospace, and implantable devices like anastomosing devices and bone screws used in biomedicine. Most metal wires are produced through a process of extrusion / rolling, room temperature drawing, and intermediate annealing, such as steel wire, Al alloy wire, and Cu alloy wire. These metals possess good room temperature plastic deformation capabilities, allowing for room temperature drawing deformation under high strain rates and large cumulative strain conditions. Intermediate annealing eliminates the stored deformation energy, restoring the material's plastic deformation capability. Repeating room temperature drawing and intermediate annealing yields wires of specific diameters. However, some metals, such as Ti alloys and Mg alloys, have limited room temperature plastic deformation capabilities due to their crystal structure, which restricts the number of slip systems and twins that can be activated at room temperature. Conventional room temperature drawing and intermediate annealing processes often result in small single-pass deformation, small cumulative deformation, and numerous intermediate annealing cycles, leading to low forming efficiency and a significantly increased risk of wire breakage. To address the aforementioned issues, a hot drawing process was developed, which involves drawing and deforming wire at a specific temperature. This process can significantly increase the deformation per pass while reducing or eliminating the need for intermediate annealing.

[0003] However, hot drawing processes typically employ a tubular furnace with drawing equipment or a linear arrangement of an induction furnace and drawing equipment, requiring high heating power and a large floor space. Furthermore, the heating temperature, heating time, drawing rate, and furnace length of the metal wire are mutually restrictive, generally resulting in low hot drawing production rates. Therefore, optimizing hot drawing equipment and processes to further improve the production efficiency of Ti and Mg alloy wires remains a significant challenge. Summary of the Invention

[0004] To address the problems existing in the current hot drawing process, this invention provides a continuous high-speed hot drawing device and process for metal wires, which solves the problem of low production efficiency caused by the mutual constraints between the heating temperature, heating time, drawing rate and furnace length of the metal wire in the current hot drawing process. It is especially suitable for the efficient hot drawing preparation of difficult-to-deform materials such as Ti alloys and Mg alloys.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A continuous high-speed hot drawing device for metal wire includes a wire feeding frame, at least one set of hot drawing units, and a winding device, wherein... The hot drawing unit includes a guide wheel, a lubricant coating device, a material storage preheating device, a tension adjustment device, and a hot drawing forming device arranged sequentially along the wire processing path; The material storage preheating device is equipped with a drum material storage mechanism and a resistance heating device arranged around it. The tension adjustment device is located between the material storage preheating device and the hot drawing forming device, and is used to detect and stabilize the running tension of the wire in real time. The hot drawing forming apparatus includes a drawing die and a drawing work roll.

[0006] Furthermore, the guide wheel is used to change the running direction of the filament, ensuring that the filament enters the subsequent lubricant coating device smoothly and without twisting from the pay-off stand. The surface of the guide wheel may have grooves matching the diameter of the filament to prevent the filament from jumping off the groove or sliding laterally during high-speed operation.

[0007] Furthermore, the lubricant coating device uses a high-temperature resistant lubricant. After the filament enters the device, it is immersed in or passes through the lubricating medium by a guide wheel, ensuring that a complete lubricating film is formed on the circumferential surface of the filament.

[0008] Furthermore, the roller storage mechanism is a rotatable roller on which the filament is wound and stored in multiple layers to achieve a continuous production mode of "feeding, heating and drawing simultaneously".

[0009] Furthermore, to minimize heat loss from the filament, the distance between the filament storage mechanism and the drawing die is maintained at 20±5cm to ensure that the filament remains at a relatively high temperature when it enters the die, thereby improving its plastic deformation capacity.

[0010] The present invention also provides a continuous high-speed hot drawing process for metal wire using the above-mentioned device, comprising the following steps: Step 1: The metal wire is drawn out from the wire feeding frame, guided by the guide wheel, and then lubricant is evenly coated on the surface of the wire by the lubricant coating device. Step 2: The filament enters the storage and preheating device, and the filament is stored on the drum storage mechanism. The surrounding resistance heating device is turned on for preheating. Step 3: After the preheated wire is adjusted and stabilized by the tension regulating device, it enters the hot drawing forming device and is subjected to high-speed hot drawing deformation through the drawing die. Step 4: The finished filaments after drawing are wound up and collected by a winding device.

[0011] Furthermore, in step 2, the storage volume is 10-500 m³.

[0012] Furthermore, in step 2, the winding speed of the material storage device of the preheating device is 10-100 m / min, the preheating temperature is controlled at 200℃-600℃, and the preheating time is 1 minute-5 minutes.

[0013] Furthermore, in step 3, the drawing speed is controlled at 10-100 m / min.

[0014] The beneficial effects of this invention are as follows: 1. The hot drawing device of the present invention adds a material storage preheating device to realize the "material storage preheating + high-speed hot drawing" of wire. By pre-storing and heating a section of wire through the drum storage mechanism, a continuous production mode of "feeding, heating and drawing at the same time" is realized. By matching the heating temperature, heating time, hot drawing speed and storage amount, the hot drawing speed is greatly improved, avoiding the limitation of drawing rate on the traditional straight heating process. It is especially suitable for difficult-to-deform materials such as magnesium alloys and titanium alloys, and has significant application value.

[0015] 2. The material preheating device in the hot drawing device of the present invention uses resistance heating for preheating and heat preservation. Since resistance heating has a simple structure, is easy to maintain, and has precise temperature control and is easy to adjust, it can meet the heating requirements of different metal materials. Compared with induction heating, resistance heating is more likely to meet the needs of factory production.

[0016] 3. In the hot drawing device of the present invention, the distance between the storage roll and the hot drawing die is minimized to reduce the heat loss of the wire and ensure that the wire can maintain a sufficiently high temperature when entering the drawing die, thus having a high plastic deformation capacity. The storage roll and the drawing roll are reasonably matched to make the wire taut and tightly wound on the roll, ensuring that the hot drawing process is carried out at high speed and stably.

[0017] 4. In this invention, the guide wheel, lubricant coating device, material storage preheating device, tension adjustment device and hot drawing forming device are one unit. By connecting multiple units in series, continuous hot drawing can be achieved, which further improves the production efficiency of hot drawn wire. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the continuous high-speed hot drawing device for metal wire described in Embodiment 1 of the present invention: Figure 2 This is a schematic diagram of the hot drawing unit. In the diagram: 1-Payout frame; 2-Guide wheel; 3-Lubricant coating device; 4-Preheating storage device; 5-Drum storage mechanism; 6-Resistance heating device; 7-Tension adjustment device; 8-Hot drawing forming device; 9-Drawing die; 10-Drawing working drum; 11-Rewinding device; 12-Annular SiC furnace chamber; 13-Resistance wire; 14-Thermocouple; 15-Alumina ceramic fiber refractory material; 16-Stainless steel shell.

[0019] Figure 3 The image shows the microstructure of the Φ1 mm Ti-6Al-4V alloy wire prepared in Example 2 of this invention.

[0020] Figure 4 The room temperature tensile stress-strain curve of the Φ1 mm Ti-6Al-4V alloy wire prepared in Example 2 of this invention. Detailed Implementation

[0021] The technical solution and effects of the present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto. Example 1

[0022] like Figure 1 As shown, this embodiment provides a continuous high-speed hot drawing device for metal wire, including a wire feeding frame 1, at least one set of hot drawing units, and a winding device 11, wherein... The hot drawing unit includes a guide wheel 2, a lubricant coating device 3, a material storage preheating device 4, a tension adjustment device 7, and a hot drawing forming device 8 arranged sequentially along the wire processing path.

[0023] Furthermore, the guide wheel 2 is used to change the running direction of the wire, ensuring that the wire enters the subsequent lubricant coating device 3 smoothly and without twisting from the wire feeding frame 1.

[0024] In this embodiment, a groove matching the diameter of the wire can be formed on the surface of the guide wheel 2 to prevent the wire from jumping out of the groove or sliding laterally during high-speed operation.

[0025] Furthermore, the lubricant coating device 3 uses a high-temperature resistant lubricant, such as graphite lubricant. After the filament enters the device, it is immersed in or passes through the lubricating medium by the guide wheel 2, ensuring that a complete lubricating film is formed on the circumferential surface of the filament. After being preheated by the resistance heating device, a dense lubricating film is formed.

[0026] Furthermore, the material storage preheating device 4 is equipped with a drum material storage mechanism 5 and a resistance heating device 6 arranged around it. The filament is wound on the high-temperature drum, which is equivalent to an annealing treatment, which is beneficial to the stability of subsequent drawing. Compared with the unidirectional heating of the straight-in furnace tube, multi-layer winding on the drum can make the filament heat more evenly and avoid the "shaded side" phenomenon.

[0027] In this embodiment, the drum storage mechanism 5 is a rotatable drum on which the filament is wound and stored in multiple layers to achieve a continuous production mode of "feeding, heating, and drawing simultaneously". The drum storage mechanism 5 is used to actively wind and store a section of filament before drawing, allowing the filament to be wound in multiple layers. The amount of filament stored by the drum storage mechanism 5 is preferably 50-200 meters. The dense lubricating film coated on the surface of the filament can effectively prevent surface wear of the filament caused by friction between filaments and between the filament and the drum.

[0028] like Figure 2 As shown, in this embodiment, the resistance heating device 6 includes a resistance wire 13 wound around the outside of an annular SiC furnace chamber 12, an alumina ceramic fiber refractory material 15 wrapped around the outside of the resistance wire 13, and a stainless steel outer shell 16 on the outermost side. A thermocouple 14 is fixed to the middle of the stainless steel outer shell 16. A 20mm gap is maintained between the inner side of the annular SiC furnace chamber 12 and the outer circumference of the winding storage mechanism 5 to prevent direct contact between the wire and the resistance wire 13 in case of wire breakage, while ensuring high heating efficiency. The thermocouple 14 penetrates the stainless steel outer shell 16, the alumina ceramic fiber refractory material 15, and the annular SiC furnace chamber 12, extending into the gap between the annular SiC furnace chamber 12 and the winding storage mechanism 5 to measure and control the temperature in the resistance heating device 6. The alumina ceramic fiber refractory material 15 tightly fills the gaps between the resistance wire 13 and the stainless steel outer shell 16, and between the annular SiC furnace chamber 12 and the stainless steel outer shell 16, to reduce heat loss to the stainless steel outer shell 16, ensuring that the resistance heating device 6 efficiently, accurately, and uniformly heats and maintains the temperature of the stored wire.

[0029] Furthermore, the tension adjusting device 7 is used to ensure that the filament is tightly wound on the spool and maintain a stable operating tension, ensuring the continuity, high speed, and stability of the hot drawing process. The tension adjusting device 7 is located between the material storage preheating device 4 and the hot drawing forming device 8, and is used to detect and stabilize the operating tension of the filament in real time.

[0030] Furthermore, the hot drawing forming apparatus 8 includes a drawing die 9 and a drawing work roll 10. The drawing die 9 is a conventional structure used to achieve hot drawing deformation of the wire.

[0031] To minimize heat loss from the filament, the distance between the spool storage mechanism 5 and the drawing die 9 is maintained at 20±5cm to ensure that the filament can maintain a high temperature when it enters the die, thereby improving its plastic deformation capacity.

[0032] In this embodiment, the preheating device 4 and the hot drawing forming device 8 are powered by independent motors and reducers to provide power to their respective drums, ensuring coordinated speed of the filament between the two devices. When there is a difference between the speed at which the filament is released by the drum storage mechanism 5 of the preheating device 4 and the speed at which the filament is received by the drawing drum 10 of the hot drawing forming device 8, the tension of the filament will fluctuate. The tension regulating device 7 senses the tension change through its internal tension detection mechanism (such as a floating roller or tension sensor) and automatically adjusts its actuator (such as the position of the swing arm or the torque of the brake) to compensate for the filament's unwinding and winding, thereby eliminating tension fluctuations. Through the active control of the tension regulating device 7, it is ensured that the filament maintains a constant tension before entering the drawing die 9, avoiding unexpected deformation of the filament at high temperatures due to excessive tension or slippage of the filament on the drawing drum 10 due to insufficient tension. This stable tension is also a prerequisite for ensuring that the filament is tightly wound in multiple layers on each drum of the preheating device 4 and the hot drawing forming device 8, achieving continuous high-speed production.

[0033] During operation, the wire fed from the pay-off frame 1 is lubricated and then enters the storage and preheating device 4. When it is necessary to increase the storage capacity or to connect continuous production, the drum storage mechanism 5 rotates at a speed V1 driven by a motor, winding the wire in multiple layers around the drum for storage. At the same time, the resistance heating device 6 is energized to heat the wire wound on the drum evenly. Since the storage drum and the drawing drum at the rear end are controlled by their respective independent transmission systems, by adjusting the speed difference between the two (i.e., the relationship between V1 and the drawing speed V2), the drum storage mechanism 5 can be used as a buffer area to store or release the wire when drawing is paused or the speed changes. After sufficient preheating time (1-5 minutes) on the drum, the wire is detached from the drum and quickly enters the hot drawing die 9 through a very short 20cm gap. At this time, the wire still maintains the target preheating temperature, thus completing plastic deformation at high temperature. Example 2

[0034] The preparation of Ti-6Al-4V (TC4) alloy wire using the apparatus described in Example 1 includes the following steps: Step 1: Using TC4 alloy Φ3.0 mm wire rod as raw material, place it on the wire feeding frame 1. After being guided by the guide wheel 2, the wire enters the lubricant coating device 3, where graphite lubricant is evenly coated on its surface.

[0035] Step 2: After the lubricant is applied, the filament enters the storage and preheating device 4. The winding speed of the drum storage mechanism 5 is controlled to be 100 m / min. The resistance heating device 6 is turned on to preheat the filament to 600°C. The filament is wound and stored in multiple layers on the drum. The preheating time is 3 minutes.

[0036] Step 3: After the preheated filament is adjusted and kept under stable tension by the tension regulating device 7, it enters the hot drawing forming device 8. The filament is hot drawn by the drawing die 9. The drawing speed is set to 100 m / min. After four consecutive hot drawing passes, the filament is drawn from the initial Φ3.0 mm to Φ1.0 mm (the cumulative strain reaches 88.9%).

[0037] Step 4: The finished filament after drawing is wound and collected by the winding device 11.

[0038] The metallographic microstructure of the TC4 alloy wire prepared in this embodiment is as follows: Figure 3 As shown, most α-Ti grains are equiaxed with an average grain size of about 3 μm, while a small number of α-Ti grains are fibrous in shape parallel to the drawing direction.

[0039] The room temperature tensile stress-strain curve of TC4 alloy wire is as follows: Figure 4 As shown, its room temperature tensile yield strength reaches 1120 MPa, tensile strength reaches 1300 MPa, and elongation reaches 7.5%.

[0040] As can be seen, the apparatus and process of this invention avoid the problem of drawing breakage caused by insufficient temperature rise or excessively rapid temperature drop in conventional processes, and avoid repeated shutdowns and reheating and deformation processes, thus improving production efficiency to a certain extent. The prepared filament has a uniform microstructure and good strength-plasticity matching. Example 3

[0041] The preparation of Mg-9.5Gd-4Y-2Zn-0.3Zr alloy wire using the apparatus described in Example 1 includes the following steps: Step 1: Using the 6 mm Mg-9.5Gd-4Y-2Zn-0.3Zr alloy wire rod obtained by extrusion as raw material, place it on the wire feeding frame 1. After being guided by the guide wheel 2, the wire enters the lubricant coating device 3, where graphite lubricant is uniformly coated on its surface.

[0042] Step 2: After the lubricant is applied, the filament enters the storage and preheating device 4. The winding speed of the drum storage mechanism 5 is controlled to be 10 m / min. The resistance heating device 6 is turned on to preheat the filament to 450°C. The filament is wound and stored in multiple layers on the drum. The preheating time is 5 minutes.

[0043] Step 3: After the preheated filament is adjusted and kept under stable tension by the tension regulating device 7, it enters the hot drawing forming device 8. The filament is hot drawn by the drawing die 9. The drawing speed is set to 10 m / min. After four consecutive hot drawing passes, the filament is drawn from the initial Φ6 mm to Φ3 mm (the cumulative strain reaches 75%).

[0044] Step 4: The finished filament after drawing is wound and collected by the winding device 11.

[0045] Using the apparatus and process of this invention, continuous high-speed hot drawing of Mg-9.5Gd-4Y-2Zn-0.3Zr alloy wire was achieved, effectively solving the problems of low drawing rate and small deformation per pass in room temperature drawing of this alloy. Example 4

[0046] The preparation of Mg-3Al-1Zn (i.e., AZ31) alloy wire using the apparatus described in Example 1 includes the following steps: Step 1: Using the 3.0 mm AZ31 alloy wire rod obtained by extrusion as raw material, place it on the wire feeding frame 1. After being guided by the guide wheel 2, the wire enters the lubricant coating device 3, where graphite lubricant is uniformly coated on its surface.

[0047] Step 2: After the lubricant is applied, the filament enters the storage and preheating device 4. The winding speed of the drum storage mechanism 5 is controlled to be 60 m / min. The resistance heating device is turned on to preheat the filament to 200°C. The filament is wound and stored in multiple layers on the drum. The preheating time is 1 minute.

[0048] Step 3: After the preheated filament is adjusted and kept under stable tension by the tension regulating device 7, it enters the hot drawing forming device 8. The filament is hot drawn by the drawing die 9. The drawing speed is set to 60 m / min. After four consecutive hot drawing passes, the filament is drawn from the initial Φ3.0 mm to Φ1.6 mm (cumulative strain reaches 71.5%).

[0049] Step 4: The finished filament after drawing is wound and collected by the winding device 11.

[0050] The apparatus and process of this invention avoid the problem of drawing breakage caused by insufficient temperature rise or excessively rapid temperature drop in conventional processes, and significantly improve the production efficiency of AZ31 alloy wire.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A continuous high-speed hot drawing device for metal wire, characterized in that, Includes a pay-off frame, at least one set of hot drawing units, and a winding device, wherein, The hot drawing unit includes a guide wheel, a lubricant coating device, a material storage preheating device, a tension adjustment device, and a hot drawing forming device arranged sequentially along the wire processing path; The material storage preheating device is equipped with a drum material storage mechanism and a resistance heating device arranged around it. The tension adjustment device is located between the material storage preheating device and the hot drawing forming device, and is used to detect and stabilize the running tension of the wire in real time. The hot drawing forming apparatus includes a drawing die and a drawing work roll.

2. The continuous high-speed hot drawing device for metal wire as described in claim 1, characterized in that, The guide wheel surface has a groove that matches the diameter of the wire to prevent the wire from jumping out of the groove or sliding laterally during high-speed operation.

3. The continuous high-speed hot drawing device for metal wire as described in claim 1, characterized in that, The lubricant coating device uses a high-temperature resistant lubricant.

4. The continuous high-speed hot drawing device for metal wire as described in claim 1, characterized in that, The roller storage mechanism is a rotatable roller on which the filament is wound and stored in multiple layers, realizing a continuous production mode of "feeding, heating and drawing at the same time".

5. The continuous high-speed hot drawing device for metal wire as described in claim 1, characterized in that, The distance between the roll storage mechanism and the drawing die is maintained at 20±5cm to ensure that the wire can still maintain a high temperature when it enters the die, thereby improving its plastic deformation ability.

6. A continuous high-speed hot drawing process for metal wire, characterized in that, Includes the following steps: Step 1: The metal wire is drawn out from the wire feeding frame, guided by the guide wheel, and then lubricant is evenly coated on the surface of the wire by the lubricant coating device. Step 2: The filament enters the storage and preheating device, and the filament is stored on the drum storage mechanism. The surrounding resistance heating device is turned on for preheating. Step 3: After the preheated wire is adjusted and stabilized by the tension regulating device, it enters the hot drawing forming device and is subjected to high-speed hot drawing deformation through the drawing die. Step 4: The finished filaments after drawing are wound up and collected by a winding device.

7. The process as described in claim 6, characterized in that, In step 2, the storage volume is 10-500 m³.

8. The process as described in claim 6, characterized in that, In step 2, the winding speed of the material storage device in the preheating device is 10-100 m / min, the preheating temperature is controlled at 200℃-600℃, and the preheating time is 1 minute-5 minutes.

9. The process as described in claim 6, characterized in that, In step 3, the drawing speed is controlled at 10-100 m / min.

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