Metal pipe continuous preparation device and using method thereof

Abstract

The invention relates to a metal pipe continuous preparation device and a using method thereof. The metal pipe continuous preparation device comprises an outer shell, a plate guiding piece, an extrusion forming assembly, a high-frequency electromagnetic induction heating device and a non-contact ultrasonic vibration device. The extrusion forming assembly is composed of a main extrusion wheel, an auxiliary extrusion wheel and an arc-shaped guide limiting block. And the main extrusion wheel, the auxiliary extrusion wheel and the arc-shaped guide limiting block jointly form a continuous forming cavity of the metal plate. The device integrates the functions of metal plate introduction, continuous multi-wheel extrusion, high-frequency electromagnetic induction heating, non-contact ultrasonic vibration treatment and diameter expansion, realizes short-process and continuous pipe preparation, and is especially suitable for pipe preparation of black and non-ferrous metal materials such as reduced and ultra-fast cooling pipeline steel developed under the guidance of cost reduction and efficiency improvement at present; the problems of long flow and high energy consumption caused by large internal stress of materials and difficult forming in traditional UOE and other processes are solved, and the method has the advantages of structure refinement, high welding seam strength, high adaptability, energy conservation, environmental protection and the like.

Description

Technical Field

[0001] This invention relates to the field of metal pipe manufacturing technology, and in particular to a highly efficient continuous metal pipe manufacturing apparatus and its method of use. Background Technology

[0002] Metal pipes are widely used in oil and gas transportation, chemical industry, aerospace and other fields. Among them, straight seam welded pipes are gradually becoming the mainstream choice for long-distance pipelines due to their high production efficiency, good dimensional accuracy and low residual stress. Traditional straight seam welded pipe manufacturing processes, such as UOE forming and JCOE forming processes, are relatively mature, but they suffer from problems such as large equipment, dispersed processes, high energy consumption, long processes, many molds, and low material utilization. In particular, current pipeline steel material research and development is moving towards "cost reduction and efficiency improvement" by reducing alloy content and optimizing rolling controlled cooling processes (such as using ultra-fast cooling technology) to fully utilize the water cooling strengthening effect. However, the reduced-weight, high-strength materials produced by these processes suffer from high internal stress and significant springback during subsequent pipe manufacturing, making them unsuitable for traditional multi-step forming processes. For example, in the U-forming stage of the UOE process, high-strength steel plates often need to be bent multiple times, making direct one-step forming impossible, resulting in a longer process, reduced efficiency and increased costs.

[0003] To address the aforementioned issues, existing technologies largely optimize the traditional "segmented forming + post-welding" process framework from different dimensions. These optimizations can be summarized as follows: (1) Alloy composition and material design optimization: The forming and welding properties of the material itself are improved by optimizing the proportion of specific elements and the rolling process. For example, the Chinese patent application CN202410529758.8, which discloses "A pipeline steel with excellent high and low temperature performance, JCOE pipeline and its preparation", optimizes the chemical composition of the steel (such as the proportion of C, Si, Mn and microalloying elements Nb, V and Ti) and the controlled rolling and cooling process, aiming to make the steel itself have excellent high and low temperature toughness and weldability so as to better withstand the subsequent multi-step forming and welding thermal cycles. It adopts the idea of ​​"material-based process", but does not change the complexity of the process itself.

[0004] (2) Tube forming process optimization: The tube forming process itself is precisely controlled, and the research focuses on improving the accuracy and efficiency of individual links. For example, the Chinese patent application CN202310637478.4 discloses "A JCOE tube shape control method", which optimizes the bending parameters of each step of the JCOE process through intelligent algorithms and introduces online detection and feedback to reduce the ellipticity and misalignment of the final tube. In essence, it uses intelligent means to "precisely" repair the traditional discrete forming process, which not only does not change the complexity of the process itself, but also increases the difficulty of control.

[0005] (3) Specific optimization of welding technology: Focusing on the key quality link of welding in traditional pipe manufacturing, such as the "Manufacturing method of JCOE straight seam submerged arc welded pipe of X80 pipeline steel" disclosed in Chinese patent application CN200710185346.3 and the "JCOE steel pipe weld multi-wire submerged arc welding process parameter optimization system" disclosed in Chinese patent application CN201810324567.2, for high-strength pipeline steel such as X80, the straight seam submerged arc welding parameters (such as current, voltage, speed, welding wire angle, etc.) in the JCOE process are optimized to ensure the toughness of high-strength welds. Although such improvements enhance the performance of welded joints of specific materials, they further solidify the technical route that relies on large-scale special welding equipment and multi-pass filler welding. In addition, regarding welding heat sources, although induction welding equipment has been developed, such as the "An Electromagnetic Induction Welding Head and Electromagnetic Induction Welding Equipment" disclosed in Chinese patent application CN201920230904.1, which achieves efficient heating, it is usually used as an independent welding unit and is not coupled with the upstream forming process.

[0006] The aforementioned improvements, in essence, do not break through the limitations of traditional technical routes. Equipment, space, and production processes remain separate, resulting in lengthy production lines, repeated material positioning and transfer, high overall energy consumption, and extremely complex coordination of process parameters at each stage. Therefore, there is an urgent need to develop a new type of efficient, continuous, and adaptable pipe manufacturing equipment and process to overcome the systemic shortcomings of existing technologies in terms of efficiency, energy consumption, and material adaptability, and to meet the development needs of a green, short-process, and intelligent pipe manufacturing industry. Summary of the Invention

[0007] This invention provides a continuous metal pipe manufacturing apparatus and its usage method, which integrates metal sheet introduction, continuous multi-round extrusion, high-frequency electromagnetic induction heating, non-contact ultrasonic vibration treatment, and diameter expansion functions to achieve short-process, continuous pipe manufacturing. It is particularly suitable for the manufacturing of ferrous and non-ferrous metal materials such as reduced-volume and ultra-fast cooling pipeline steel developed under the current cost reduction and efficiency improvement policy. It solves the problems of long process and high energy consumption caused by high internal stress and forming difficulties in traditional UOE processes. It has the advantages of fine structure, high weld strength, strong adaptability, energy saving and environmental protection.

[0008] To achieve the above objectives, the present invention employs the following technical solution: A continuous metal tube manufacturing apparatus includes an outer shell, a sheet guide, and an extrusion forming assembly, a high-frequency electromagnetic induction heating device, and a non-contact ultrasonic vibration device disposed within the outer shell. The top of the outer shell has a sheet inlet, and the sheet guide is located at the inlet. The extrusion forming assembly consists of a main extrusion roller, secondary extrusion rollers, and multiple arc-shaped guide and limiting blocks. The main extrusion roller is located in the center of the inner cavity of the outer shell, and multiple secondary extrusion rollers are arranged circumferentially around its periphery. An open-structure sheet introduction section is formed between the two secondary extrusion rollers below the sheet inlet. Each auxiliary extrusion roller is equipped with an arc-shaped guide and limiting block, which is coaxially arranged. Each auxiliary extrusion roller and each arc-shaped guide and limiting block can move radially along the distribution circle. The main extrusion roller can move in a plane perpendicular to the axial direction within the circumference formed by the auxiliary extrusion rollers and the arc-shaped guide and limiting blocks. The main extrusion roller, auxiliary extrusion rollers, and arc-shaped guide and limiting blocks together form a continuous forming cavity for the metal sheet. The bottom of the continuous forming cavity is provided with a welding fine grain position. The high-frequency electromagnetic induction heating device and the non-contact ultrasonic vibration device can both move and switch between their respective initial positions and the welding fine grain position.

[0009] A continuous metal tube manufacturing apparatus further includes a control system; the control ends of the high-frequency electromagnetic induction heating device and the non-contact ultrasonic vibration device are respectively connected to the control system, and the control system is also connected to the movement control ends of the main extrusion wheel, the auxiliary extrusion wheel and the arc-shaped guide limit block.

[0010] The solid phase welding position is also equipped with a temperature measuring device, and the signal output terminal of the temperature measuring device is connected to the control system.

[0011] The sheet metal guide is used to guide the sheet metal into the continuous forming cavity; the sheet metal guide includes a sheet metal inlet plate, which is inclined.

[0012] The metal sheet is a magnetic metal sheet, and the sheet guide also includes magnetic attraction rollers; the sheet guide plate is inclined, and multiple magnetic attraction rollers are arranged on the top of the sheet guide plate along the moving direction of the metal sheet.

[0013] The number of auxiliary extrusion rollers and arc-shaped guide limit blocks is 4 to 10.

[0014] A method of using a continuous metal tube manufacturing apparatus includes the following steps: (1) Introduction of metal sheet and continuous deformation: The main extrusion roller is initially positioned at the center of the outer shell. The positions of the secondary extrusion roller and the arc-shaped guide block are adjusted to make the width of the continuous forming cavity match the cross-sectional dimensions of the metal sheet. The tilt angle of the sheet guide plate is adjusted to make it tangent to the continuous forming cavity. The main extrusion roller and the secondary extrusion roller are started, and they rotate relative to each other, introducing the metal sheet, which is moving down along the sheet guide plate, into the continuous forming cavity from the sheet guide section. Through the action of rubbing friction shearing, the metal sheet is continuously deformed into a cylindrical shape, and its surface structure is refined. After forming, the joint between the first and last ends of the metal sheet is moved to the welding fine grain position. (2) Solid phase welding and solidification structure control: The high-frequency electromagnetic induction heating device is moved to the welding fine grain position and started, and instantaneous high-frequency electromagnetic induction heating is performed on the joint of the first and last ends of the metal sheet. The temperature is monitored in real time using a temperature measuring device. After heating to the semi-solid temperature range of the metal sheet, the arc-shaped guide limit block is controlled to move radially inward to apply extrusion pressure to the metal sheet and realize solid-phase welding at the joint of the first and last ends. After welding is completed, the high-frequency electromagnetic induction heating device returns to the initial position, and the non-contact ultrasonic vibration device is moved to the welding fine grain position and started, and ultrasonic vibration is used to optimize the solidification morphology of the weld and refine the grains. (3) Secondary reinforcement of weld and pipe diameter expansion: After the weld cools, the main extrusion roller and the auxiliary extrusion roller rotate in opposite directions to perform reverse friction shear deformation on the weld area, further refining the weld structure and improving the connection strength. Subsequently, the auxiliary extrusion roller and the arc-shaped guide limit block are adjusted to move radially outward, and the main extrusion roller expands and rolls outward along the normal direction of the formed metal pipe to expand the diameter of the metal pipe.

[0015] When a metal sheet is magnetic, the introduction speed is controlled by the attraction of a magnetically drawn guide roller when it is introduced into a continuous forming cavity.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1) High integration and short process: This invention integrates multiple functions such as material introduction, forming, welding, internal structure control, and diameter expansion into a single device. Compared with conventional tube manufacturing methods such as UOE and JCOE, it eliminates material transfer and multiple clamping processes between processes, making each process closely connected, greatly shortening the production process, improving production efficiency, and reducing energy consumption and floor space.

[0017] 2) Excellent pipe and weld quality: The rubbing shear friction force drives the metal sheet to move along the tangential direction of the main extrusion wheel, which increases the effective strain during the deformation process and significantly refines the surface microstructure of the metal sheet, improving the surface strength of the pipe while maintaining its core flexibility; high-frequency induction solid-phase welding is adopted, combined with ultrasonic vibration to refine the solidification structure (compared with conventional UOE, JCOE and other pipe manufacturing methods, it eliminates the welding and cutting processes of the arc-starting plate at the head and the arc-extinguishing plate at the tail of the sheet), and then secondary strengthening is carried out by reverse friction shearing, resulting in high weld strength, uniform structure, narrow heat-affected zone, no need for filler metal, low cost and good environmental performance.

[0018] 3) Adaptable to high-strength, low-weight materials: Through continuous extrusion and friction shear deformation, the internal stress of the sheet material is effectively eliminated, avoiding the springback problem during U-forming in traditional processes. It is especially suitable for low-alloy high-strength pipeline steel and other materials prepared by ultra-fast cooling processes, and is also suitable for the efficient, continuous and stable preparation of pipes corresponding to other ferrous alloy and non-ferrous alloy sheets.

[0019] 4) Strong flexible production capability: By adjusting the position of the auxiliary extrusion roller and the arc module through hydraulic means, it can adapt to plates of different thicknesses and widths and various pipe diameters without increasing the number of equipment, realizing multi-purpose use of one machine and improving equipment utilization and production flexibility. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a continuous metal tube manufacturing apparatus according to the present invention.

[0021] In the diagram: 1. Outer shell; 2. Sheet metal guide plate; 3. Magnetic attraction guide roller; 4. Metal sheet; 5. Inner cavity; 6. Main extrusion roller; 7. Secondary extrusion roller; 8. Arc-shaped guide limiting block; 9. Continuous forming cavity; 10. Metal tube; 11. End joint; 12. High-frequency electromagnetic induction heating device; 13. Non-contact ultrasonic vibration device; 14. Control system. Detailed Implementation

[0022] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: like Figure 1As shown, the continuous metal pipe manufacturing apparatus of the present invention includes an outer shell 1, a plate guide, and an extrusion forming assembly, a high-frequency electromagnetic induction heating device 12, and a non-contact ultrasonic vibration device 13 placed inside the outer shell 1. The top of the outer shell 1 has a plate inlet, and the plate guide is located at the plate inlet. The extrusion forming assembly consists of a main extrusion roller 6, secondary extrusion rollers 7, and multiple arc-shaped guide and limiting blocks 8. The main extrusion roller 6 is located in the middle of the inner cavity 5 of the outer shell 1, and multiple secondary extrusion rollers 7 are arranged circumferentially around the main extrusion roller 6. An open plate introduction section is formed between the two secondary extrusion rollers 7 below the plate inlet. Each of the remaining auxiliary extrusion rollers 7 is provided with an arc-shaped guide limit block 8, which is coaxially arranged. Each auxiliary extrusion roller 7 and each arc-shaped guide limit block 8 can move radially along the distribution circle. The main extrusion roller 6 can make a planar motion perpendicular to the axial direction within the circumference formed by the auxiliary extrusion rollers 7 and the arc-shaped guide limit blocks 8. The main extrusion roller 6, the auxiliary extrusion rollers 7, and the arc-shaped guide limit blocks 8 together form the continuous forming cavity 9 of the metal sheet 4. The bottom of the continuous forming cavity 9 is provided with a welding fine grain position. The high-frequency electromagnetic induction heating device 12 and the non-contact ultrasonic vibration device 13 can both move and switch between their respective initial positions and welding fine grain positions.

[0023] The continuous metal pipe manufacturing apparatus of the present invention further includes a control system 14; the control terminals of the high-frequency electromagnetic induction heating device 12 and the non-contact ultrasonic vibration device 13 are respectively connected to the control system 14, and the control system 14 is also connected to the movement control terminals of the main extrusion roller 6, the auxiliary extrusion roller 7 and the arc-shaped guide limit block 8.

[0024] The solid phase welding position is also equipped with a temperature measuring device, and the signal output terminal of the temperature measuring device is connected to the control system 14.

[0025] The sheet metal guide is used to guide the metal sheet 4 into the continuous forming cavity 9; the sheet metal guide includes a sheet metal inlet plate 2, which is inclined.

[0026] The metal plate 4 is a magnetic metal plate, and the plate guide also includes magnetic attraction rollers 3; the plate guide plate 2 is inclined, and multiple magnetic attraction rollers 3 are arranged on the top of the plate guide plate 2 along the moving direction of the metal plate 4.

[0027] The number of the auxiliary extrusion rollers 7 and the arc-shaped guide limit blocks 8 is 4 to 10.

[0028] The method of using the continuous metal tube manufacturing apparatus of the present invention includes the following steps: (1) Introduction of metal sheet and continuous deformation: The main extrusion roller 6 is initially positioned at the center of the outer shell 1. The positions of the auxiliary extrusion roller 7 and the arc-shaped guide block 8 are adjusted so that the width of the continuous forming cavity 9 is adapted to the cross-sectional dimensions of the metal sheet 4. The tilt angle of the sheet guide plate 2 is adjusted so that it is tangent to the continuous forming cavity 9. The main extrusion roller 6 and the auxiliary extrusion roller 7 are started, and they rotate relative to each other. The metal sheet 4, which moves down along the sheet guide plate 2, is introduced into the continuous forming cavity 9 from the sheet guide section. Through the rubbing friction shearing action, the metal sheet 4 is continuously deformed into a cylindrical shape, and its surface structure is refined. After forming, the joint between the first and last ends of the metal sheet 4 is moved to the welding fine grain position. (2) Solid phase welding and solidification structure control: The high-frequency electromagnetic induction heating device 12 is moved to the welding fine grain position and started, and instantaneous high-frequency electromagnetic induction heating is performed on the joint of the first and last ends of the metal plate 4. The temperature is detected in real time using a temperature measuring device. After heating to the semi-solid temperature range of the metal plate 4, the arc-shaped guide limit block 8 is controlled to move radially inward to apply extrusion pressure to the metal plate 4, thereby realizing solid-phase welding at the joint of the first and last ends. After welding is completed, the high-frequency electromagnetic induction heating device 12 returns to the initial position, and the non-contact ultrasonic vibration device 13 is moved to the welding fine grain position and started, using ultrasonic vibration to optimize the solidification structure morphology of the weld and refine the grains. (3) Secondary reinforcement of weld and pipe diameter expansion: After the weld cools, the main extrusion roller 6 and the auxiliary extrusion roller 7 rotate in opposite directions to perform reverse friction shear deformation on the weld area, further refining the weld structure and improving the connection strength. Subsequently, the auxiliary extrusion roller 7 and the arc-shaped guide limit block 8 are adjusted to move outward radially, and the main extrusion roller 6 expands and rolls outward along the normal direction of the formed metal pipe 10 to expand the diameter of the metal pipe 10.

[0029] When the metal sheet 4 is magnetic, the introduction speed is controlled by the adsorption effect of the magnetic attraction guide roller 3 when it is introduced into the continuous forming cavity 9.

[0030] The continuous metal pipe preparation device of the present invention can realize the efficient continuous preparation of metal pipes. The angle adjustment system of the plate guide plate 2 is preferably implemented by a hydraulic system to precisely control the introduction speed of the metal plate 4. Several magnetic attraction guide rollers 3 can be set on the top of the plate guide plate 2 to attract and guide the metal plate 4 to move downward. While controlling the downward speed of the metal plate 4, scratches on the surface of the metal plate 4 can also be avoided.

[0031] In the initial state, the main extrusion roller 6, the auxiliary extrusion roller 7, and the arc-shaped guide limiting block 8 are coaxially arranged, and together they form an annular continuous forming cavity 9. The auxiliary extrusion roller 7 and the arc-shaped guide limiting block 8 can move radially (preferably hydraulically driven) to adjust the cross-sectional dimensions of the continuous forming cavity 9 to meet the forming requirements of metal sheets 10 with different thicknesses.

[0032] The bottom of the continuous forming cavity 9 is provided with a high-frequency electromagnetic induction heating device 12 and a non-contact ultrasonic vibration device 13, both of which are movable (preferably hydraulically driven) and used to perform solid-phase welding and ultrasonic vibration fine grain operation on the joint of the formed metal tube 10.

[0033] After the metal sheet 4 is introduced into the continuous forming cavity 9, the main extrusion roller 6 and the auxiliary extrusion roller 7 rotate relative to each other (e.g., the main extrusion roller 6 rotates counterclockwise and the auxiliary extrusion roller 7 rotates clockwise). Together with the arc-shaped guide and limiting block 8, they apply continuous frictional shearing to the metal sheet 4, gradually shaping it into a cylindrical form. During this process, the surface grains of the metal sheet 4 are significantly refined, and because a continuous deformation method is used, the internal stress of the metal sheet 4 (especially high-strength steel plates) can be effectively relieved, avoiding the springback problem during multi-step U-forming in traditional forming processes.

[0034] After the metal sheet 4 is formed into the metal tube 10, its end joint 11 is moved to the bottom of the continuous forming cavity 9 and stopped. The end joint 11 is heated to a semi-solid state using a high-frequency electromagnetic induction heating device 12 (temperature is measured using a temperature measuring device). Then, it is pressed inward by the arc-shaped guide limiting block 8 to achieve solid-phase welding. Finally, the non-contact ultrasonic vibration device 13 is moved below the end joint 11 to vibrate the weld, achieving the purpose of refining the grains and homogenizing the composition.

[0035] After the weld solidifies, the main extrusion roller 6 and the auxiliary extrusion roller 7 rotate in opposite directions (e.g., the main extrusion roller 6 rotates clockwise and the auxiliary extrusion roller 7 rotates counterclockwise) to perform secondary friction shearing on the weld, further breaking down coarse structures and increasing strength. Finally, the positions of the auxiliary extrusion roller 7 and the arc-shaped guide limit block 8 are adjusted, and the main extrusion roller 6 moves outward to expand the diameter of the metal pipe 10, bringing it to the finished size.

[0036] This invention is particularly applicable to reduced-weight pipeline steel produced using an ultra-fast cooling process. Under high cooling rates, this material is prone to generating large internal stresses, making it difficult for traditional pipe-making processes to form efficiently. However, this invention achieves high-quality and efficient pipe-making for this type of material through continuous shearing and online welding.

[0037] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A continuous metal tube manufacturing apparatus, characterized in that, The device includes an outer shell, a sheet metal guide, and an extrusion forming assembly, a high-frequency electromagnetic induction heating device, and a non-contact ultrasonic vibration device housed within the outer shell. The top of the outer shell has a sheet metal inlet, and the sheet metal guide is located at the inlet. The extrusion forming assembly consists of a main extrusion roller, auxiliary extrusion rollers, and multiple arc-shaped guide and limiting blocks. The main extrusion roller is located in the center of the inner cavity of the outer shell, and multiple auxiliary extrusion rollers are arranged circumferentially around its periphery. An open sheet metal introduction section is formed between the two auxiliary extrusion rollers below the sheet metal inlet, and the remaining auxiliary extrusion rollers... Each part is equipped with an arc-shaped guide limiting block, which is coaxially arranged; each auxiliary extrusion wheel and each arc-shaped guide limiting block can move radially along the distribution circle, and the main extrusion wheel can make a planar movement perpendicular to the axial direction within the circumference formed by the auxiliary extrusion wheel and the arc-shaped guide limiting block; the main extrusion wheel, auxiliary extrusion wheel and arc-shaped guide limiting block together form a continuous forming cavity for the metal sheet; the bottom of the continuous forming cavity is provided with a welding fine grain position, and the high-frequency electromagnetic induction heating device and the non-contact ultrasonic vibration device can move and switch between their respective initial positions and welding fine grain positions.

2. The continuous metal tube manufacturing apparatus according to claim 1, characterized in that, It also includes a control system; the control ends of the high-frequency electromagnetic induction heating device and the non-contact ultrasonic vibration device are respectively connected to the control system, and the control system is also connected to the movement control ends of the main extrusion wheel, the auxiliary extrusion wheel and the arc-shaped guide limit block.

3. The continuous metal tube manufacturing apparatus according to claim 1, characterized in that, The solid phase welding position is also equipped with a temperature measuring device, and the signal output terminal of the temperature measuring device is connected to the control system.

4. The continuous metal tube manufacturing apparatus according to claim 1, characterized in that, The sheet metal guide is used to guide the sheet metal into the continuous forming cavity; the sheet metal guide includes a sheet metal inlet plate, which is inclined.

5. The continuous metal tube manufacturing apparatus according to claim 4, characterized in that, The metal sheet is a magnetic metal sheet, and the sheet guide also includes magnetic attraction rollers; the sheet guide plate is inclined, and multiple magnetic attraction rollers are arranged on the top of the sheet guide plate along the moving direction of the metal sheet.

6. The continuous metal tube manufacturing apparatus according to claim 1, characterized in that, The number of auxiliary extrusion rollers and arc-shaped guide limit blocks is 4 to 10.

7. A method of using the continuous metal tube manufacturing apparatus as described in any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Introduction and continuous deformation of metal sheet: The main extrusion roller is initially positioned at the center of the outer shell. The positions of the secondary extrusion roller and the arc-shaped guide block are adjusted to make the width of the continuous forming cavity adapt to the cross-sectional dimensions of the metal sheet. Adjust the tilt angle of the sheet metal guide plate to make it tangent to the continuous forming cavity; start the main extrusion roller and the auxiliary extrusion roller, which rotate relative to each other, and introduce the metal sheet moving down along the sheet metal guide plate into the continuous forming cavity from the sheet metal guide section. Through the rubbing friction shearing action, the metal sheet is continuously deformed into a cylindrical shape and its surface structure is refined; after forming, move the end joint of the metal sheet to the welding fine grain position. (2) Solid phase welding and solidification structure control: The high-frequency electromagnetic induction heating device is moved to the welding fine grain position and started, and instantaneous high-frequency electromagnetic induction heating is performed on the joint of the first and last ends of the metal sheet. The temperature is monitored in real time using a temperature measuring device. After heating to the semi-solid temperature range of the metal sheet, the arc-shaped guide limit block is controlled to move radially inward to apply extrusion pressure to the metal sheet and realize solid-phase welding at the joint of the first and last ends. After welding is completed, the high-frequency electromagnetic induction heating device returns to the initial position, and the non-contact ultrasonic vibration device is moved to the welding fine grain position and started, and ultrasonic vibration is used to optimize the solidification morphology of the weld and refine the grains. (3) Secondary reinforcement of weld and pipe diameter expansion: After the weld cools, the main extrusion roller and the auxiliary extrusion roller rotate in opposite directions to perform reverse friction shear deformation on the weld area, further refining the weld structure and improving the connection strength. Subsequently, the auxiliary extrusion roller and the arc-shaped guide limit block are adjusted to move radially outward, and the main extrusion roller expands and rolls outward along the normal direction of the formed metal pipe to expand the diameter of the metal pipe.

8. The continuous metal tube manufacturing apparatus according to claim 7, characterized in that, When a metal sheet is magnetic, the introduction speed is controlled by the attraction of a magnetically drawn guide roller when it is introduced into a continuous forming cavity.

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