Device and method for preparing gradient nanostructure on inner and outer wall of metal pipe

Abstract

The application discloses a device and method for preparing gradient nanostructure on inner and outer walls of metal pipes, and belongs to the technical field of inner and outer wall processing of metal pipes. The device and method solve the problems of complex structure and incapability of simultaneously preparing gradient nanostructure on inner and outer walls of metal pipes in the prior art. The first fixing device, the outer wall rolling device and the second fixing device are arranged on the mounting platform. The first fixing device is provided with the pipe rotating device. The first fixing device reciprocally moves relative to the outer wall rolling device. The second fixing device is provided with the pipe fixing device and the inner wall rolling device. The inner and outer cutters are oppositely arranged when the gradient nanostructure is prepared on the metal pipe. The device and method for preparing gradient nanostructure on inner and outer walls of metal pipes are used for preparing gradient nanostructure on inner and outer walls of metal pipes. The device has a simple structure and can simultaneously prepare gradient nanostructure on inner and outer walls of metal pipes at low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of inner and outer wall processing of metal pipes, and in particular relates to a device and method for preparing gradient nanostructures on the inner and outer walls of metal pipes. Background Art

[0002] Metal pipes are widely used as the "blood vessels" that transport gases and liquids in military and civilian industrial equipment, as well as supporting components. However, with the increasing efficiency and lightweighting of industrial equipment, higher requirements are being placed on pipes' strength, toughness, oxidation resistance, acid and alkali corrosion resistance, and wear resistance. Therefore, how to improve the overall performance and service life of metal pipes has long been a focus of researchers.

[0003] At present, a large number of studies have proved that the metal surface can be treated by surface modification technology, thereby creating a structure different from the original structure, which can significantly improve the comprehensive performance of the metal. At present, there are various technical methods for strengthening the inner and outer surfaces of metal pipes, such as surface spraying technology, surface deposition technology, surface chemical heat treatment technology, shot peening technology, etc. However, spraying technology and surface chemical heat treatment technology can improve the performance of metal pipes in certain service areas to a certain extent. However, the application of these technologies has many shortcomings in pipe strengthening. For example, there is a clear interface between the strengthening layer and the matrix. When affected by stress, heat, and chemical effects, the strengthening layer and the matrix layer are easily peeled off, thereby failing to achieve the purpose of strengthening the pipe surface. In addition, if these technologies are used to strengthen the inner and outer walls of metal pipes at the same time, the processing technology is cumbersome, the equipment is complex, and the cost is high.

[0004] A gradient nanocrystalline structure in metals refers to a gradual transition from nanocrystalline to coarse-grained structures on the metal surface and within its interior, thus avoiding the problem of a sharp interface between the strengthening layer and the matrix. Furthermore, numerous studies have shown that a surface gradient nanocrystalline structure can significantly improve the strength and plasticity of metals, achieving a synergistic effect of strength and plasticity. Furthermore, since damage such as wear and corrosion typically first occurs on the metal surface, a surface gradient nanocrystalline structure can effectively increase the metal's hardness, thereby reducing these hazards. By applying the principle of large surface plastic deformation to the metal surface, large plastic deformation can achieve a gradient nanostructure with grain refinement down to the nanometer scale. While various methods and techniques exist for large plastic deformation, limited technologies are available due to the unique shape of pipes. Existing technologies for creating a gradient nanocrystalline structure on pipe surfaces through large plastic deformation include shot peening and pulse impact technology. However, due to limitations in shot peening and impact strength, the gradient nanocrystalline structure produced on the metal pipe surface is typically not distinct, resulting in a thin strengthening layer and poor strengthening effect, with minimal improvement in the overall performance and service life of the metal pipe. In addition, the existing surface gradient nanocrystalline structure strengthening technology has problems such as complex equipment, long process flow, and high processing cost. It is also unable to perform large plastic deformation on the inner and outer walls of the metal pipe at the same time, resulting in low efficiency and poor quality in the preparation of gradient nanostructures on the inner and outer walls of the metal pipe. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a device and method for preparing gradient nanostructures on the inner and outer walls of metal pipes. The device structure and preparation process are simple, and gradient nanostructures can be prepared on the inner and outer walls of metal pipes at the same time at low cost and high efficiency.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The present invention discloses a device for preparing gradient nanostructures on the inner and outer walls of a metal pipe, comprising a mounting platform, on which a first fixing device, a pipe outer wall rolling device, and a second fixing device are sequentially arranged, the first fixing device being provided with a pipe rotating device, the first fixing device being reciprocating relative to the pipe outer wall rolling device, the second fixing device being provided with a pipe fixing device and a pipe inner wall rolling device; the pipe outer wall rolling device comprising a first telescopic device, the front end of a first telescopic rod of the first telescopic device being provided with a pipe outer wall rolling tool, the pipe inner wall rolling device comprising a second telescopic device, the front end of a second telescopic rod of the second telescopic device being provided with a third telescopic device, the front end of a third telescopic rod of the third telescopic device being provided with a pipe inner wall rolling tool, the pipe outer wall rolling tool and the pipe inner wall rolling tool being arranged relative to each other when working to prepare the gradient nanostructure.

[0008] Furthermore, the first telescopic device, the second telescopic device and the third telescopic device are all hydraulic cylinders.

[0009] Furthermore, the depth to which the tube outer wall rolling tool and the tube inner wall rolling tool are pressed into the corresponding outer wall and inner wall of the metal tube is H, and 10 μm≤H≤100 μm.

[0010] Furthermore, the installation platform is provided with a first slide rail, and the first fixing device reciprocates along the first slide rail relative to the pipe outer wall rolling device.

[0011] Furthermore, the first fixing device is provided with a second slide rail, the pipe rotating device moves along the second slide rail, and the second fixing device is provided with a third slide rail, the pipe fixing device and the second telescopic device move along the third slide rail.

[0012] Furthermore, the tube outer wall rolling tool and the tube inner wall rolling tool are both spherical tools.

[0013] Furthermore, the spherical tool includes a tool holder and a spherical blade. The tool holder is provided with a spherical groove that cooperates with the spherical blade. The spherical blade is rotatably arranged in the spherical groove.

[0014] Furthermore, a lubricating layer is provided between the inner wall of the spherical groove and the spherical blade.

[0015] Furthermore, a rubber ring is provided on the groove edge of the spherical groove.

[0016] A method for preparing gradient nanostructures on the inner and outer walls of a metal tube according to the above structure comprises the following steps:

[0017] S1, fixing one end of the metal tube to be prepared with the gradient nanostructure on the tube rotating device, and clamping the other end of the metal tube on the tube fixing device;

[0018] S2, the tube outer wall rolling device and the tube inner wall rolling device are in operation, the first telescopic rod of the first telescopic device is extended, driving the tube outer wall rolling tool to abut against the outer wall of the metal tube, setting the pressing depth of the tube outer wall rolling tool; the second telescopic rod of the second telescopic device is extended, driving the third telescopic device to extend into the metal tube, and the third telescopic rod of the third telescopic device is extended, driving the tube inner wall rolling tool to abut against the inner wall of the metal tube, setting the pressing depth of the tube inner wall rolling tool, and the tube outer wall rolling tool is arranged opposite to the tube inner wall rolling tool;

[0019] S3, the tube rotating device rotates to drive the metal tube to rotate, and at the same time controls the first fixing device to reciprocate relative to the tube outer wall rolling device, so that the tube outer wall rolling tool presses down on the outer wall of the metal tube to plastically deform it, and the tube inner wall rolling tool presses down on the inner wall of the metal tube to plastically deform it;

[0020] S4. The outer wall and the inner wall of the metal tube are prepared into a gradient nanostructure.

[0021] The beneficial effects of the present invention are:

[0022] This application provides a device for forming gradient nanostructures on the inner and outer walls of metal pipes. The device comprises a mounting platform, a first fixture, a pipe rotating device, a first telescopic device, a pipe outer wall rolling tool, a second fixture, a pipe fixture, a second telescopic device, a third telescopic device, and a pipe inner wall rolling tool. The device has a simple structure and low manufacturing and operating costs. When preparing gradient nanostructures on the inner and outer walls of a metal pipe, the two ends of the metal pipe are respectively fixed on a pipe rotating device and clamped on a pipe fixing device. When the first telescopic device works, the first telescopic rod extends so that the pipe outer wall rolling tool is against the outer wall of the metal pipe and pressed down to a designed depth; when the second telescopic device works, the second telescopic rod extends to drive the third telescopic device to extend into the metal pipe, and the pipe outer wall rolling tool is arranged opposite to the pipe inner wall rolling tool; when the third telescopic device works, the third telescopic rod extends so that the pipe inner wall rolling tool is against the inner wall of the metal pipe and pressed down to a designed depth; the pipe rotating device works and rotates to drive the metal pipe to rotate, and the pipe outer wall rolling tool radially mechanically presses the outer wall of the metal pipe. During rolling, the outer wall of the metal tube undergoes large radial plastic deformation to form a gradient nanostructure. The inner wall rolling tool mechanically rolls the inner wall of the metal tube radially, causing large radial plastic deformation to form a gradient nanostructure. Simultaneously, the first fixing device reciprocates relative to the outer wall rolling device, and the outer wall rolling tool mechanically rolls the outer wall of the metal tube axially, causing large axial plastic deformation to form a gradient nanostructure. The inner wall rolling tool mechanically rolls the inner wall of the metal tube axially, causing large axial plastic deformation to form a gradient nanostructure. This simultaneously completes the preparation of gradient nanostructures on the inner and outer walls of the metal tube, improving the efficiency of preparing gradient nanostructures on the inner and outer walls of the metal tube. The process for preparing gradient nanostructures on the inner and outer walls of the metal tube is simple, efficient, and low-cost, and can complete the preparation of gradient nanostructures on the inner and outer walls of the metal tube at low cost and high efficiency. The gradient nanostructure formed by the mechanical rolling method has a thick strengthening layer and an obvious strengthening effect. The gradient nanostructure strengthening layer will not peel off from the base layer of the metal pipe, which improves the quality of the gradient nanostructure of the inner and outer walls of the metal pipe, thereby greatly improving the comprehensive performance and service life of the metal pipe, such as strength, toughness, oxidation resistance, acid and alkali corrosion resistance, and wear resistance. The pipe rotating device drives the metal pipe to rotate and the first fixing device to move back and forth relative to the pipe outer wall rolling device, so that the gradient nanostructure of the inner and outer walls of the metal pipe is uniformly prepared, and the inner and outer walls of the metal pipe simultaneously produce grain refinement, further improving the quality of the gradient nanostructure of the inner and outer walls of the metal pipe, and further improving the comprehensive performance and service life of the metal pipe. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe provided in the present application can not only prepare gradient nanostructures on the inner and outer walls of the metal pipe at the same time, but also prepare gradient nanostructures on the outer wall of the metal pipe alone, and can also prepare gradient nanostructures on the inner wall of the metal pipe alone, which is very convenient.The present application also provides a method for preparing gradient nanostructures on the inner and outer walls of a metal pipe based on an apparatus for preparing gradient nanostructures on the inner and outer walls of a metal pipe, which can simultaneously prepare gradient nanostructures on the inner and outer walls of a metal pipe at low cost and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 Schematic diagram of the device for preparing gradient nanostructures on the inner and outer walls of a metal pipe provided by an embodiment of the present invention for preparing gradient nanostructures on a metal pipe;

[0025] Figure 2 This is a state diagram of the preparation of gradient nanostructures on metal pipes by the pipe inner wall rolling tool and the pipe outer wall rolling tool provided in an embodiment of the present invention;

[0026] Figure 3 Schematic diagram of the structure of a spherical tool provided by an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the device for preparing gradient nanostructures on the inner and outer walls of a metal tube with a protective cover provided in an embodiment of the present invention for preparing gradient nanostructures on a metal tube;

[0028] Figure 5 This is a schematic diagram of a gradient nanostructure prepared by an apparatus for preparing a gradient nanostructure on the inner and outer walls of a metal pipe provided by an embodiment of the present invention.

[0029] Figure numerals: mounting platform 1, first slide rail 2, first fixing device 3, pipe rotating device 4, second slide rail 5, metal pipe 6, pipe inner wall rolling tool 7, third telescopic rod 8, third telescopic device 9, second telescopic rod 10, second telescopic device 11, pipe fixing device 12, second telescopic device base 13, second fixing device 14, third slide rail 15, pipe outer wall rolling tool 16, first telescopic rod 17, first telescopic device 18, first telescopic device base 19, spherical tool 20, tool holder 201, spherical blade 202, lubricating layer 21, rubber ring 22, protective cover 23, medium injection port 24. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] The present invention will be further described below with reference to the accompanying drawings and examples.

[0032] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5As shown, this embodiment provides a device for preparing gradient nanostructures on the inner and outer walls of a metal tube, comprising a mounting platform 1, on which a first fixing device 3, a tube outer wall rolling device and a second fixing device 14 are sequentially arranged, the first fixing device 3 is provided with a tube rotating device 4, the first fixing device 3 moves back and forth relative to the tube outer wall rolling device, the second fixing device 14 is provided with a tube fixing device 12 and a tube inner wall rolling device; the tube outer wall rolling device comprises a first telescopic device 18, the front end of a first telescopic rod 17 of the first telescopic device 18 is provided with a tube outer wall rolling tool 16, the tube inner wall rolling device comprises a second telescopic device 11, the front end of a second telescopic rod 10 of the second telescopic device 11 is provided with a third telescopic device 9, the front end of a third telescopic rod 8 of the third telescopic device 9 is provided with a tube inner wall rolling tool 7, the tube outer wall rolling tool 16 and the tube inner wall rolling tool 7 are arranged relative to each other when working to prepare the gradient nanostructure. The first telescopic device 18, the second telescopic device 11, and the third telescopic device 9 can be hydraulic cylinders or pneumatic cylinders. The pipe rotating device 4 is a disk with side guards. The side guards of the disk are evenly arranged with at least three push rods arranged along the radial direction of the disk. The side guards are provided with screw holes that match the push rods. The push rods are threadedly connected to the side guards. The left end of the metal pipe 6 is placed in the disk. The push rods are tightened to press against the outer wall of the metal pipe 6 to fix the metal pipe 6 to the disk. The disk is connected to the output shaft of the motor. When the motor is started, the output shaft rotates to drive the disk to rotate, driving the metal pipe 6 to rotate. The first fixing device 3 reciprocates relative to the pipe outer wall rolling device under the action of a slider guide mechanism or a screw mechanism or a hydraulic cylinder or a pneumatic cylinder. Alternatively, if the factory has a lathe or drilling machine, the lathe or drilling machine has a rotating device and a horizontal moving device. The left end of the metal pipe 6 is fixed to the rotating device of the lathe or drilling machine. This rotating device can be used as the pipe rotating device 4, and the lathe or drilling machine can be used as the first fixing device 3. The pipe fixing device 12 supports the metal pipe 6. The pipe fixing device 12 is a cylinder, and the right end of the metal pipe 6 rotates inside the cylinder; or the pipe fixing device 12 is a clamping roller, and the pipe wall of the metal pipe 6 is clamped between the clamping rollers, and the metal pipe 6 rotates between the clamping rollers.

[0033] A device for preparing gradient nanostructures on the inner and outer walls of a metal tube based on the above structure is used to prepare gradient nanostructures on the inner and outer walls of a metal tube 6, such as Figure 5 As shown, Figure 5 The upper half of the dotted line in FIG is a metallographic image of a metal tube 6 after a gradient nanostructure is prepared on the inner and outer walls of the metal tube by using the device for preparing a gradient nanostructure. Figure 5The lower half of the dotted line in the figure is a metallographic diagram of the base layer structure of the metal tube 6. It is composed of a mounting platform 1, a first fixing device 3, a tube rotating device 4, a first telescopic device 18, a tube outer wall rolling tool 16, a second fixing device 14, a tube fixing device 12, a second telescopic device 11, a third telescopic device 9 and a tube inner wall rolling tool 7. The structure of the device is simple and the manufacturing and use costs are low. When preparing gradient nanostructures on the inner and outer walls of the metal tube 6, the two ends of the metal tube 6 are respectively fixed on the tube rotating device 4 and clamped on the tube fixing device 12 (such as the left end of the metal tube 6 is fixed on the tube rotating device 4, and the right end of the metal tube 6 is clamped on the tube fixing device 12). When the first telescopic device 18 works, the first telescopic rod 17 of the first telescopic device 18 extends to make the tube outer wall rolling tool 16 collide with the outer wall of the metal tube 6 and press down to the designed depth (the depth of preparing the gradient nanostructure); when the second telescopic device 11 works, the second telescopic device The second telescopic rod 10 of the device 11 is extended to drive the third telescopic device 9 to extend into the metal tube 6, so that the tube outer wall rolling tool 16 is arranged opposite to the tube inner wall rolling tool 7; the third telescopic device 9 works, and the third telescopic rod 8 of the third telescopic device 9 is extended, so that the tube inner wall rolling tool 7 is against the inner wall of the metal tube 6 and pressed down to the designed depth; the tube rotating device 4 works and rotates to drive the metal tube 6 to rotate, and the tube outer wall rolling tool 16 mechanically rolls the outer wall of the metal tube 6 in the radial direction, and the outer wall of the metal tube 6 is locally plastically deformed to form a gradient nanostructure, and the inner wall of the tube is deformed. The rolling tool 7 mechanically rolls the inner wall of the metal tube 6 in the radial direction, and the inner wall of the metal tube 6 undergoes a large local plastic deformation in the radial direction to form a gradient nanostructure; at the same time, the first fixing device 3 reciprocates relative to the tube outer wall rolling device (or the second fixing device 14), and the tube outer wall rolling tool 16 mechanically rolls the outer wall of the metal tube 6 in the axial direction, and the outer wall of the metal tube 6 undergoes a large local plastic deformation in the axial direction to form a gradient nanostructure; the tube inner wall rolling tool 7 mechanically rolls the inner wall of the metal tube 6 in the axial direction, and the inner wall of the metal tube 6 undergoes a large local plastic deformation in the axial direction to form a gradient nanostructure, and the metal tube is completed at the same time. The gradient nanostructures are formed on the inner and outer walls of the metal tube 6, thereby improving the efficiency of forming the gradient nanostructures on the inner and outer walls of the metal tube 6. For example, if the same gradient nanostructure is formed on the inner and outer walls of the metal tube 6, existing devices require first forming the gradient nanostructure on the outer wall of the metal tube 6 and then forming the gradient nanostructure on the inner wall of the metal tube 6. However, the present device for forming the gradient nanostructures on the inner and outer walls of the metal tube 6 simultaneously forms the gradient nanostructures on both the inner and outer walls of the metal tube 6, halving the cycle time for forming the gradient nanostructures on the inner and outer walls of the metal tube 6 and significantly improving the efficiency of forming the gradient nanostructures on the inner and outer walls of the metal tube 6. The process for forming the gradient nanostructures on the inner and outer walls of the metal tube 6 is simple, highly efficient, and low-cost, and can efficiently and cost-effectively form the gradient nanostructures on the inner and outer walls of the metal tube 6.The gradient nanostructures on the inner and outer walls of the metal tube 6 formed by mechanical rolling have a thick strengthening layer and a significant strengthening effect. The gradient nanostructure strengthening layer will not peel off from the base layer of the metal tube 6, thereby improving the quality of the gradient nanostructures on the inner and outer walls of the metal tube 6, thereby greatly improving the comprehensive performance and service life of the metal tube 6, such as strength, toughness, oxidation resistance, acid and alkali corrosion resistance, and wear resistance. The tube rotating device 4 drives the metal tube 6 to rotate and the first fixing device 3 to move back and forth relative to the tube outer wall rolling device, so that the gradient nanostructures on the inner and outer walls of the metal tube 6 are uniformly prepared, and the inner and outer walls of the metal tube 6 simultaneously produce grain refinement, further improving the quality of the gradient nanostructures on the inner and outer walls of the metal tube 6, and further improving the comprehensive performance and service life of the metal tube 6. The device for preparing gradient nanostructures on the inner and outer walls of a metal tube provided in this embodiment can not only prepare gradient nanostructures on the inner and outer walls of the metal tube 6 at the same time, but can also prepare gradient nanostructures on the outer wall of the metal tube 6 separately, and can also prepare gradient nanostructures on the inner wall of the metal tube 6 separately, which is very convenient.

[0034] Preferably, the first telescopic device 18, the second telescopic device 11 and the third telescopic device 9 are all hydraulic cylinders.

[0035] The hydraulic cylinder has a simple structure, high control accuracy, fast response speed, strong adaptability, and can stably provide strong thrust and pull forces, making it suitable for use as the first telescopic device 18, the second telescopic device 11, and the third telescopic device 9 of the present application. A first telescopic device base 19 is provided on the mounting platform 1, and a second telescopic device base 13 is provided on the second fixing device 14. The hydraulic cylinder of the first telescopic device 18 is mounted on the first telescopic device base 19, and the hydraulic cylinder of the second telescopic device 11 is mounted on the second telescopic device base 13.

[0036] The depth to which the tube outer wall rolling tool 16 and the tube inner wall rolling tool 7 are pressed into the corresponding outer wall and inner wall of the metal tube 6 is H, and 10 μm≤H≤100 μm.

[0037] The depth H of the tube outer wall rolling tool 16 pressed into the outer wall of the metal tube 6 and the depth H of the tube inner wall rolling tool 7 pressed into the outer wall of the metal tube 6 can be within 10μm to 100μm, and can be specifically selected according to the designed processing size and performance of different metal tubes 6, such as the pressing depth is 10μm, 20μm, 50μm, 80μm or 100μm.

[0038] As an implementable method, Figure 1 、 Figure 4 As shown, the installation platform 1 is provided with a first slide rail 2, and the first fixing device 3 reciprocates along the first slide rail 2 relative to the pipe outer wall rolling device.

[0039] For example, the first slide rail 2, the first fixing device 3 is connected to a slider that slides with the first slide rail 2, and the corresponding motor is connected to this slider through a connecting rod mechanism. The motor is connected to an external power supply, and the motor is electrically connected to the controller. The controller controls the motor to start, driving the first fixing device 3 to move back and forth on the first slide rail 2, thereby realizing axial local large plastic deformation of the inner and outer walls of the metal pipes 6 of different lengths to form a gradient nanostructure.

[0040] As an implementable method, Figure 1 、 Figure 4 As shown, the first fixing device 3 is provided with a second slide rail 5, the pipe rotating device 4 moves along the second slide rail 5, the second fixing device 14 is provided with a third slide rail 15, the pipe fixing device 12 and the second telescopic device 11 move along the third slide rail 15.

[0041] When the diameter of the metal tube 6 is large, the tube rotating device 4 moves upward along the second slide rail 5, while the tube fixing device 12 and the second telescopic device 11 move upward along the third slide rail 15. When the diameter of the metal tube 6 is small, the tube rotating device 4 moves downward along the second slide rail 5, while the tube fixing device 12 and the second telescopic device 11 move downward along the third slide rail 15. This achieves large local axial plastic deformation of the inner and outer walls of the metal tubes 6 of different diameters to form a gradient nanostructure. The pipe rotating device 4 is connected to a slider that slides with the second slide rail 5, and the corresponding motor is connected to this slider through a connecting rod mechanism. The motor is externally powered and electrically connected to the controller. The controller controls the motor to start or stop, driving the pipe rotating device 4 to slide on the second slide rail 5. When the pipe rotating device 4 slides to a suitable position, the motor stops running, and the pipe rotating device 4 stops sliding; the pipe fixing device 12 and the second telescopic device 11 are respectively connected to the corresponding slider that slides with the third slide rail 15, and the corresponding motor is connected to the corresponding slider through a connecting rod mechanism. The motor is externally powered and electrically connected to the controller. The controller controls the motor to start or stop, driving the pipe fixing device 12 and the second telescopic device 11 to slide on the third slide rail 15. When the pipe fixing device 12 and the second telescopic device 11 slide to a suitable position, the motor stops running, and the pipe fixing device 12 and the second telescopic device 11 stop sliding. When the hydraulic cylinder of the second telescopic device 11 is installed on the second telescopic device base 13, the second telescopic device base 13 is connected to the corresponding slider that slides with the third slide rail 15, the motor is connected to an external power supply, and the motor is electrically connected to the controller, and the controller controls the start or stop of the motor.

[0042] As an implementable method, Figure 1 、 Figure 3 、 Figure 4 As shown, the tube outer wall rolling tool 16 and the tube inner wall rolling tool 7 are both spherical tools 20 .

[0043] The spherical tool 20 serves as the outer wall rolling tool 16 and the inner wall rolling tool 7 for mechanical rolling, reducing damage to the inner and outer walls of the metal pipe 6, ensuring a smooth mechanical rolling process, making the gradient nanostructure formed on the inner and outer walls of the metal pipe 6 more uniform, improving the quality of the gradient nanostructure on the inner and outer walls of the metal pipe 6, and improving the comprehensive performance and service life of the metal pipe 6.

[0044] As an implementable method, Figure 3 As shown, the spherical tool 20 includes a tool seat 201 and a spherical blade 202. The tool seat 201 is provided with a spherical groove that matches the spherical blade 202. The spherical blade 202 is rotatably arranged in the spherical groove.

[0045] The spherical tool 20 is composed of a spherical blade 202 placed in a spherical groove of a tool seat 201. The spherical blade 202 rotates in the spherical groove of the seat 201 and extends out of the groove edge of the spherical groove. It has a simple structure and low manufacturing and maintenance costs.

[0046] As an implementable method, Figure 3 As shown, a lubricating layer 21 is provided between the inner wall of the spherical groove and the spherical blade 202 .

[0047] A lubricating layer 21 , such as a lubricating oil layer or a lubricating grease layer, is provided between the inner wall of the spherical groove and the spherical blade 202 to ensure that the spherical blade 202 runs smoothly in the blade seat 201 .

[0048] As an implementable method, Figure 3 As shown, a rubber ring 22 is provided at the groove edge of the spherical groove.

[0049] The rubber ring 22 provided along the groove edge of the spherical groove plays a sealing role, which can prevent the lubricating oil or grease from flowing out, ensuring that the spherical blade 202 runs smoothly in the tool holder 201 for a long time and reducing the wear of the spherical blade 202 and the tool holder 201.

[0050] As an implementable method, Figure 4As shown, a protective cover 23 is provided on the mounting platform 1. The first fixing device 3, the pipe rotating device 4, the first telescopic device 18, the pipe outer wall rolling tool 16, the second fixing device 14, the pipe fixing device 12, the second telescopic device 11, the third telescopic device 9, and the pipe inner wall rolling tool 7 are located within the protective cover 23. The protective cover 23 is provided with a medium injection port 24 for injecting a low-temperature medium. For example, nickel alloys have a more obvious refinement effect at low temperatures, and nickel alloy pipes can produce thicker strengthening layers at low temperatures. When preparing gradient nanostructures on nickel alloy pipes, low-temperature media such as liquid nitrogen or liquid hydrogen are injected through the medium injection port 24. Furthermore, electromagnetic induction coils, laser heating, etc. can be provided within the protective cover 23 to heat and increase the temperature of the metal pipe 6. For example, magnesium alloys are difficult to deform at low temperatures and require a certain temperature (e.g., 200°C) to complete large surface plastic deformation. The protective cover 23 is filled with a low-temperature medium, an electromagnetic induction coil, and laser heating, so that the ambient temperature can be controlled, thereby achieving large plastic deformation of the metal pipes 6 made of different materials.

[0051] A method for preparing gradient nanostructures on the inner and outer walls of a metal pipe, and an apparatus for preparing gradient nanostructures on the inner and outer walls of a metal pipe based on the above structure, comprising the following steps:

[0052] S1, fixing one end of the metal tube 6 to be prepared with the gradient nanostructure on the tube rotating device 4, and clamping the other end of the metal tube 6 on the tube fixing device 12;

[0053] S2, the tube outer wall rolling device and the tube inner wall rolling device are working, the first telescopic rod 17 of the first telescopic device 18 is extended, driving the tube outer wall rolling tool 16 to abut against the outer wall of the metal tube 6, and setting the pressing depth of the tube outer wall rolling tool 16; the second telescopic rod 10 of the second telescopic device 11 is extended, driving the third telescopic device 9 to extend into the metal tube 6, and the third telescopic rod 8 of the third telescopic device 9 is extended, driving the tube inner wall rolling tool 7 to abut against the inner wall of the metal tube 6, and setting the pressing depth of the tube inner wall rolling tool 7, and the tube outer wall rolling tool 16 is arranged opposite to the tube inner wall rolling tool 7;

[0054] S3, the tube rotating device 4 rotates to drive the metal tube 6 to rotate, and at the same time controls the first fixing device 3 to reciprocate relative to the tube outer wall rolling device, so that the tube outer wall rolling tool 16 presses down on the outer wall of the metal tube 6 to plastically deform it, and the tube inner wall rolling tool 7 presses down on the inner wall of the metal tube 6 to plastically deform it;

[0055] S4, repeat step S3 until the outer wall and the inner wall of the metal tube 6 are completely formed into a gradient nanostructure.

[0056] The above-mentioned method for preparing gradient nanostructures on the inner and outer walls of a metal tube adopts a device for preparing gradient nanostructures on the inner and outer walls of a metal tube, which is used to prepare a gradient nanostructure on the outer wall of a metal tube 6 or a gradient nanostructure on the inner wall of a metal tube 6 or a gradient nanostructure on the inner and outer walls of a metal tube 6 at the same time. The preparation process has few steps and is simple to operate. It can prepare gradient nanostructures on the inner and outer walls of a metal tube 6 at a low cost and high efficiency, thereby improving the quality of the gradient nanostructures on the inner and outer walls of a metal tube 6 and improving the comprehensive performance and service life of the metal tube 6.

[0057] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be covered by the scope of protection of the present invention.

Claims

1. A device for preparing gradient nanostructures on the inner and outer walls of a metal pipe, comprising a mounting platform (1), characterized in that: The installation platform (1) is provided with a first fixing device (3), a pipe outer wall rolling device and a second fixing device (14) in sequence. The first fixing device (3) is provided with a pipe rotating device (4). The first fixing device (3) moves back and forth relative to the pipe outer wall rolling device. The second fixing device (14) is provided with a pipe fixing device (12) and a pipe inner wall rolling device. The pipe outer wall rolling device includes a first telescopic device (18). The front end of the first telescopic rod (17) of the first telescopic device (18) is provided with a pipe outer wall rolling tool (16). The pipe inner wall rolling device includes a second telescopic device (11). The front end of the second telescopic rod (10) of the second telescopic device (11) is provided with a third telescopic device (12). The third telescopic device (9) is provided with a tube inner wall rolling tool (7) at the front end of the third telescopic rod (8) of the third telescopic device (9), and the tube outer wall rolling tool (16) and the tube inner wall rolling tool (7) are arranged relative to each other when working to prepare the gradient nanostructure. The mounting platform (1) is provided with a first slide rail (2), and the first fixing device (3) reciprocates along the first slide rail (2) relative to the tube outer wall rolling device. The first fixing device (3) is provided with a second slide rail (5), and the tube rotating device (4) moves along the second slide rail (5). The second fixing device (14) is provided with a third slide rail (15), and the tube fixing device (12) and the second telescopic device (11) move along the third slide rail (15).

2. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 1, characterized in that: The first telescopic device (18), the second telescopic device (11) and the third telescopic device (9) are all hydraulic cylinders.

3. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 1, characterized in that: The pipe outer wall rolling tool (16) and the pipe inner wall rolling tool (7) are pressed into the corresponding outer wall and inner wall of the metal pipe (6) to a depth of H, 10 μm≤H≤100 μm.

4. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 1, characterized in that: The tube outer wall rolling tool (16) and the tube inner wall rolling tool (7) are both spherical tools (20).

5. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 4, characterized in that: The spherical tool (20) comprises a tool seat (201) and a spherical blade (202); the tool seat (201) is provided with a spherical groove matched with the spherical blade (202); the spherical blade (202) is rotatably arranged in the spherical groove.

6. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 5, characterized in that: A lubricating layer (21) is provided between the inner wall of the spherical groove and the spherical blade (202).

7. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 6, characterized in that: A rubber ring (22) is provided on the groove edge of the spherical groove.

8. A method for preparing gradient nanostructures on the inner and outer walls of a metal pipe, characterized in that: The device for preparing gradient nanostructures on the inner and outer walls of a metal tube according to any one of claims 1 to 7 comprises the following steps: S1. Fixing one end of the metal tube (6) to be prepared with the gradient nanostructure on the tube rotating device (4), and clamping the other end of the metal tube (6) on the tube fixing device (12); S2, the tube outer wall rolling device and the tube inner wall rolling device are working, the first telescopic rod (17) of the first telescopic device (18) is extended, driving the tube outer wall rolling tool (16) to abut against the outer wall of the metal tube (6), and setting the pressing depth of the tube outer wall rolling tool (16); the second telescopic rod (10) of the second telescopic device (11) is extended, driving the third telescopic device (9) to extend into the metal tube (6), and the third telescopic rod (8) of the third telescopic device (9) is extended, driving the tube inner wall rolling tool (7) to abut against the inner wall of the metal tube (6), and setting the pressing depth of the tube inner wall rolling tool (7), and the tube outer wall rolling tool (16) and the tube inner wall rolling tool (7) are arranged relative to each other; S3, the tube rotating device (4) rotates to drive the metal tube (6) to rotate, and at the same time controls the first fixing device (3) to move back and forth relative to the tube outer wall rolling device, the tube outer wall rolling tool (16) presses down the outer wall of the metal tube (6) to plastically deform, and the tube inner wall rolling tool (7) presses down the inner wall of the metal tube (6) to plastically deform; S4. The outer wall and the inner wall of the metal tube (6) are prepared into a gradient nanostructure.

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