Titanium profile stretching and straightening method and device

Abstract

The invention discloses a titanium profile stretching and straightening method and device. The titanium profile stretching and straightening method comprises the following steps that S1, pressure residues are reserved during extrusion forming of a titanium alloy profile; s2, a straightening device is rapidly moved to the head of the titanium alloy profiled bar, and the head of the titanium alloy profiled bar is clamped through a hydraulic clamp of the straightening device; s3, the clamping end of the hydraulic clamp is driven to rotate so that the titanium alloy profiled bar can be twisted to be right; s4, a stretching oil cylinder of the straightening device is started, and the thermal-state titanium alloy profiled bar is stretched and straightened; and S5, the hydraulic clamp is loosened, a hot saw of the extruding machine is started to cut off pressure residues, and finally the straightened titanium alloy extruded profiled bar is obtained. According to the online straightening device, the titanium alloy profiled bar is straightened on line on the discharging roller way of the extruding machine through extrusion waste heat, the problems of bending, twisting and the like of the titanium alloy extruded profiled bar are solved, meanwhile, the device is simple in structure and good in universality, and therefore the quality and production efficiency of the titanium alloy extruded profiled bar are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of material forming technology, and in particular to a method and apparatus for stretching and straightening titanium profiles. Background Technology

[0002] Titanium and titanium alloys possess significant properties such as high specific strength, high temperature resistance, and corrosion resistance, making them widely and importantly used in marine engineering, aerospace, chemical industry, and equipment manufacturing. Profiles, being near-net-shape semi-finished products with complex cross-sections, offer high structural efficiency and excellent mechanical properties, and can be used directly as structural components with little or no processing. Common manufacturing methods for profiles include extrusion and rolling. Due to the demand for titanium alloy profiles—characterized by numerous specifications and small batches—extrusion is more suitable. However, titanium alloys exhibit high processing temperatures, high deformation resistance, and high springback. Furthermore, the extrusion dies are prone to wear, leading to common problems such as bending and torsion in extruded titanium alloy profiles. Currently, the main method for straightening titanium alloy profiles involves electrically heating and then stretching and torturing them. This method requires substantial equipment investment, and precise temperature control during electric heating is difficult, leading to fluctuations in the microstructure and mechanical properties of the titanium alloy profiles. Additionally, the low production efficiency (15-60 minutes / piece) hinders the industrial production of titanium alloy profiles. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings mentioned above by providing a method and apparatus for stretching and straightening titanium profiles, which is simple in design and can quickly straighten titanium alloy profiles.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for tensile straightening of titanium profiles, comprising the following steps: S1. During the extrusion molding of titanium alloy profiles, a pressure allowance is reserved to fix the tail of the titanium alloy profile to the extrusion die through the pressure allowance. S2. Quickly move the straightening device to the head of the titanium alloy profile, and clamp the head of the titanium alloy profile using the hydraulic clamp of the straightening device. S3. Drive the hydraulic clamping end to rotate, which is used to straighten the titanium alloy profile. S4. Start the tension cylinder of the straightening device to stretch and straighten the hot titanium alloy profile. S5. Release the hydraulic clamps and start the extrusion press hot saw to remove the excess pressure, finally obtaining the straightened titanium alloy extruded profile.

[0005] Furthermore, the residual thickness in step S1 is 5-15 mm, and the cross-sectional shape of the titanium alloy profile includes, but is not limited to, U, T, L, Z, cross, and Y shapes, with a cross-sectional area of ​​300-4000 mm². 2The length of the profile is 2-20m.

[0006] Furthermore, in step S2, the straightening device moves to the head of the profile within 10 seconds after extrusion is completed, and the clamping pressure of the hydraulic clamp holding the head of the hot titanium alloy profile is 15-25 MPa.

[0007] Furthermore, the hydraulic clamp rotation method described in step S3 can be either automatic control rotation or manual rotation.

[0008] Furthermore, in step S4, the straightening temperature during the straightening of the hot titanium alloy profile is >700℃, and the tensile force of the tension cylinder is set to F, where F=P×S, P is the yield strength of the titanium alloy profile at high temperature during the stretching and straightening, and S is the cross-sectional area of ​​the titanium alloy profile. The initial tension is set to F1=(0.7-0.9)×F. If the profile length does not elongate, the tension is increased on the basis of F1 until the profile length elongation reaches (0.005-0.03)×L, where L is the length of the titanium alloy profile. When the length of the profile is stretched to (0.005-0.03)×L, keep the tension and stroke of the stretching cylinder constant for 2-10 minutes until the material temperature drops below 400℃.

[0009] A titanium profile tension straightening device, comprising: A movable frame on which a tension cylinder is mounted; A hydraulic motor is disposed at the moving end of the tension cylinder; A hydraulic clamp is disposed at the moving end of the hydraulic motor, which is used to drive the hydraulic clamp to clamp or release the profile.

[0010] Furthermore, the clamping end of the hydraulic clamp is adapted to the titanium alloy profile.

[0011] Furthermore, the hydraulic clamp is a mold steel clamp, and the clamping end of the hydraulic clamp is provided with anti-slip texture.

[0012] The beneficial effects of this invention are reflected in: In this invention, one end of the titanium alloy profile is fixed on the extruder using the residual heat and the die. Only the head of the profile needs to be clamped. The device has a simple structure, good versatility, and is easy to operate and clamp. In addition, the device has a high straightening temperature and requires a small straightening force, thus reducing the equipment cost. Furthermore, the titanium alloy profile is quickly straightened using the residual heat of the extrusion without the need for secondary heating, which improves production efficiency. At the same time, it avoids the adverse effects of temperature control deviations during electric heating on the microstructure and properties of the profile, which also significantly improves production efficiency. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the tension straightening device in this invention.

[0014] In the picture: 1. Movable frame; 2. Tension cylinder; 3. Hydraulic motor; 4. Hydraulic clamp. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Please see Figure 1 This invention discloses a method for tensile straightening of titanium profiles, comprising the following steps: S1, extruded TC4 titanium alloy cross profile, profile cross-sectional area 4000mm² 2 8m in length, with a 15mm allowance for compression, and an extrusion temperature of 1050℃, used to fix the tail of the titanium alloy profile to the extrusion die through the allowance. S2. The straightening device is pre-stopped at the front end of the mold at 9m and 1m away from the head of the extruded profile. Then, the straightening device is moved to the head of the profile within 10 seconds after the extrusion is completed. The corresponding hydraulic clamp 4 is used to clamp the head of the hot titanium alloy profile with a clamping pressure of 25MPa to ensure that the clamping end of the hydraulic clamp 4 bites into the hot titanium alloy profile. S3. Set the hydraulic clamp 4 to automatically return to the zero position and straighten the titanium alloy profile. At this time, the surface temperature of the profile reaches 900℃ and the high temperature yield strength P reaches 90MPa. S4. Start the tension cylinder 2 of the straightening device to stretch and straighten the hot titanium alloy profile. Set the tension F1=0.7×P×S=252kN. When the length of the profile extends to 0.015×L=120mm, keep the tension and stroke of the tension cylinder 2 unchanged, so that the TC4 titanium alloy cross profile is uniformly air-cooled for 10 minutes under tensile stress until the surface temperature of the profile is below 400℃. S5. Release the hydraulic clamp 4, start the extrusion press and hot saw to remove the excess pressure, and finally obtain the straightened TC4 titanium alloy cross profile. After testing, the TC4 titanium alloy cross profile after residual heat straightening has a twist of less than 0.2° / m and a straightness of less than 1.5mm / m.

[0017] Second embodiment: A method for tensile straightening of titanium profiles includes the following steps: S1, extruded TC11 titanium alloy L-shaped profile, profile cross-sectional area 400mm² 2 20m in length, with a 5mm allowance for compression, and an extrusion temperature of 960℃, used to fix the tail of the titanium alloy profile to the extrusion die through the allowance. S2. The straightening device is pre-stopped at the front end of the mold at 21.5m and 1.5m away from the head of the extruded profile. Then, the straightening device is moved to the head of the profile within 10 seconds after the extrusion is completed. The corresponding hydraulic clamp 4 is used to clamp the head of the hot titanium alloy profile with a clamping pressure of 15MPa to ensure that the clamping end of the hydraulic clamp 4 bites into the hot titanium alloy profile. S3. Set the hydraulic clamp 4 to automatically return to the zero position and straighten the titanium alloy profile. At this time, the surface temperature of the profile reaches 750-800℃ and the high temperature yield strength P reaches 150MPa. S4. Start the tension cylinder 2 of the straightening device to stretch and straighten the hot titanium alloy profile. Set the tension force F1=0.9×P×S=54kN. When the length of the profile extends to 0.005×L=100mm, keep the tension and stroke of the tension cylinder 2 unchanged, so that the TC11 titanium alloy L profile is uniformly air-cooled for 2 minutes under tensile stress until the surface temperature of the profile is below 400℃. S5. Release the hydraulic clamp 4, start the extrusion press and hot saw to remove the excess pressure, and finally obtain the straightened TC11 titanium alloy L-shaped profile. After testing, the TC11 titanium alloy L-shaped profile after residual heat straightening has a twist of less than 0.2° / m and a straightness of less than 1.5mm / m.

[0018] Third embodiment: A method for tensile straightening of titanium profiles includes the following steps: S1 and TA18 titanium alloy square (or rectangular) profiles, with a cross-sectional area of ​​1500 mm². 2 2m in length, with a 10mm allowance for compression, and an extrusion temperature of 860℃, used to fix the tail of the titanium alloy profile to the extrusion die through the allowance. S2. The straightening device is pre-stopped 3m from the front end of the mold and 1m from the head of the extruded profile. Then, the straightening device is moved to the head of the profile within 10 seconds after the extrusion is completed. The corresponding hydraulic clamp 4 is used to clamp the head of the TA18 titanium alloy square (mouth) profile with a clamping pressure of 20MPa to ensure that the clamping end of the hydraulic clamp 4 bites into the hot titanium alloy profile. S3. Set the hydraulic clamp 4 to automatically return to the zero position and straighten the titanium alloy profile. At this time, the surface temperature of the profile reaches 720℃ and the high temperature yield strength P reaches 120MPa. S4. Start the tension cylinder 2 of the straightening device to stretch and straighten the hot titanium alloy profile. Set the tension F1=0.8×P×S=144kN. When the length of the profile extends to 0.03×L=60mm, keep the tension and stroke of the tension cylinder 2 unchanged, so that the TA18 titanium alloy square (mouth) profile is uniformly air-cooled for 6 minutes under tensile stress until the surface temperature of the profile is below 400℃. S5. Release the hydraulic clamp 4, start the extrusion press hot saw to remove the excess pressure, and finally obtain the straightened TA18 titanium alloy square (U) profile. After testing, the TA18 titanium alloy square (U) profile after residual heat straightening has a twist of less than 0.2° / m and a straightness of less than 1.5mm / m.

[0019] In practice, by utilizing the residual heat from extrusion, titanium alloy profiles are straightened online on the extrusion roller conveyor, which solves the problems of bending and twisting of titanium alloy extruded profiles. At the same time, the device has a simple structure and good versatility, thus effectively improving the quality and production efficiency of titanium alloy extruded profiles.

[0020] In one embodiment, the residual thickness in step S1 is 5-15 mm, and the cross-sectional shape of the titanium alloy profile includes, but is not limited to, U, T, L, Z, cross, and Y shapes, with a cross-sectional area of ​​300-4000 mm². 2 The length of the special-shaped profile is 2-20m.

[0021] In one embodiment, the straightening device in step S2 is pre-stopped at 1-1.5m from the head of the extruded profile to ensure that the time for the straightening device to move to the head of the profile is within 10 seconds after the extrusion is completed. The clamping pressure of the hydraulic clamp 4 on the head of the hot titanium alloy profile is 15-25MPa, which ensures that the clamping end of the hydraulic clamp 4 bites into the hot titanium alloy profile.

[0022] In one embodiment, when the hydraulic clamp 4 straightens the titanium alloy profile in step S3, it is preferable that the hydraulic clamp 4 is automatically straightened and can also be manually adjusted in terms of rotation angle. The maximum torque of the hydraulic clamp 4 is 10 kN·m.

[0023] In one embodiment, during the straightening of the hot titanium alloy profile in step S4, the maximum tension of the tension cylinder 2 is 1000KN, and the maximum stroke of the cylinder is 600mm. Preferably, its straightening temperature is >700℃. The tension force of the tension cylinder 2 is set to F, where F=P×S, P is the yield strength of the titanium alloy profile at high temperature during the straightening process, and S is the cross-sectional area of ​​the titanium alloy profile. The initial tension is set to F1=0.7-0.9×F. If the profile length does not elongate, the tension is increased based on F1 until the profile length elongation reaches 0.005-0.03×L, where L is the length of the titanium alloy profile. When the profile length elongation reaches 0.005-0.03×L, the tension and stroke of the tension cylinder 2 are kept unchanged for 2-10 minutes until the material temperature drops below 400℃.

[0024] Preferably, the tensile force and length elongation will not cause significant necking or wall thinning of the hot titanium alloy profile, while allowing the profile to undergo plastic deformation. Once the length elongation of the titanium alloy profile reaches the process requirements, the preferred holding time and temperature can keep the titanium alloy profile in a state of tensile stress and air-cooled uniformly, maintaining a straightened state without springback.

[0025] In one embodiment, a titanium profile tensioning and straightening device is also included. The device includes a movable frame 1, a tension cylinder 2, a hydraulic motor 3, and a hydraulic clamp 4. The tension cylinder 2 is mounted on the movable frame 1, the hydraulic motor 3 is mounted on the moving end of the tension cylinder 2, and the hydraulic clamp 4 is mounted on the moving end of the hydraulic motor 3. The hydraulic motor 3 is used to drive the hydraulic clamp 4 to clamp or release the profile.

[0026] In one embodiment, the clamping end of the hydraulic clamp 4 is adapted to the titanium alloy profile to facilitate clamping and fixing according to different types of titanium profiles.

[0027] In one embodiment, the hydraulic clamp 4 is a mold steel clamp, and the clamping end of the hydraulic clamp 4 is provided with anti-slip texture, which can be a toothed pattern, to improve the clamping stability when the hydraulic clamp 4 clamps the corresponding titanium profile.

[0028] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0029] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0030] Additionally, "multiple" refers to two or more.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of stretch levelling of titanium sections, characterised in that, The method comprises the following steps: S1. Reserving a pressure excess during the extrusion of the titanium alloy profile, which is used to fix the tail of the titanium alloy profile at the extrusion die through the pressure excess; S2. Moving the straightening device to the head of the titanium alloy profile, clamping the head of the titanium alloy profile through the hydraulic clamp (4) of the straightening device; S3. Rotating the clamping end of the hydraulic clamp (4) to straighten the titanium alloy profile; S4. Starting the stretching oil cylinder (2) of the straightening device to stretch and straighten the hot titanium alloy profile; S5. Loosening the hydraulic clamp (4) and starting the extruder hot saw to cut off the pressure excess, and finally obtaining the straightened titanium alloy extruded profile.

2. A method of stretch levelling a titanium section according to claim 1, characterised in that: The excess thickness in step S1 is 5-15mm, the cross-sectional shape of the titanium alloy profiled bar includes but is not limited to U, T, L, Z, ten, Y shape, the cross-sectional area of the profiled bar is 300-4000mm 2 , and the length of the profiled bar is 2-20m.

3. The method according to claim 1, wherein: The time for moving the straightening device to the profile head in step S2 is within 10 seconds after the extrusion is completed, and the clamping pressure of the hydraulic clamp (4) clamping the hot titanium alloy profile head is 15-25 MPa.

4. The method according to claim 1, wherein: The rotating mode of the hydraulic clamp (4) in step S3 can be automatic control rotation or manual rotation.

5. The method according to claim 1, wherein: The straightening temperature of the hot titanium alloy profile in step S4 is greater than 700℃, and the stretching force of the stretching oil cylinder (2) is set as F, wherein F=P×S, P is the yield strength of the titanium alloy profile at high temperature during stretching and straightening, and S is the cross-sectional area of the titanium alloy profile, the initial setting tension F1=(0.7-0.9)×F, if the profile length is not elongated, the tension is increased based on F1 until the profile length extension reaches (0.005-0.03)×L, wherein L is the length of the titanium alloy profile; When the profile length stretching amount reaches (0.005-0.03)×L, the tension and stroke of the stretching oil cylinder (2) are kept unchanged for 2-10 minutes until the material temperature is reduced to below 400℃.

6. A titanium profile stretch levelling device comprising a titanium profile stretch levelling method according to any one of claims 1 to 5, characterized in that, It comprises: A movable frame (1) provided with a stretching oil cylinder (2); A hydraulic motor (3) provided at the moving end of the stretching oil cylinder (2); A hydraulic clamp (4) provided at the moving end of the hydraulic motor (3), and the hydraulic motor (3) is used to drive the hydraulic clamp (4) to clamp or loosen the profile.

7. The titanium section tensile straightening device according to claim 6, characterized in that: The clamping end of the hydraulic clamp (4) is matched with the titanium alloy profile.

8. The titanium profile stretch levelling device as claimed in claim 6, wherein: The hydraulic clamp (4) is a die steel clamp, and the clamping end of the hydraulic clamp (4) is provided with anti-slip lines.

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