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

Abstract

The invention discloses a device and method for preparing gradient nanostructures on the inner and outer walls of a metal pipe, and belongs to the technical field of machining of the inner and outer walls of the metal pipe. The problems that in the prior art, a device for preparing the gradient nanostructure on the metal pipe wall is complex in structure, and the gradient nanostructure cannot be prepared on the inner wall and the outer wall of a metal pipe at the same time are solved. A first fixing device, a pipe outer wall rolling device and a second fixing device are arranged on the mounting platform, the first fixing device is provided with a pipe rotating device and reciprocates relative to the pipe outer wall rolling device, and the second fixing device is provided with a pipe fixing device and a pipe inner wall rolling device. And the inner cutter and the outer cutter are oppositely arranged when the metal pipe is processed to prepare the gradient nanostructure. The device and method for preparing the gradient nanostructures on the inner wall and the outer wall of the metal pipe are used for preparing the gradient nanostructures on the inner wall and the outer wall of the metal pipe, the device is simple in structure, and the gradient nanostructures can be prepared on the inner wall and the outer wall of the metal pipe at the same time 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 have been widely used as "blood vessels" and supporting parts for transporting gases and liquids in military and civilian industrial equipment. However, with the improvement of efficiency and lightweight of industrial equipment, higher requirements are placed on the strength, toughness, oxidation resistance, acid and alkali corrosion resistance, and wear resistance of pipes. Therefore, how to improve the comprehensive performance and service life of metal pipes has always 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 organization, which can significantly improve the comprehensive performance of the metal. At present, there are various technical methods for strengthening the inner wall and outer surface 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, but there are many shortcomings in the application of these technologies in pipe strengthening. For example, there is an obvious interface between the strengthening layer and the matrix. When affected by stress, heat, and chemical effects, the strengthening layer and the matrix layer are easy to peel off, thereby failing to achieve the purpose of strengthening the surface of the pipe. And 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] The metal gradient nanocrystalline structure refers to the gradual transition organization of nanocrystalline-coarse crystal formed on the metal surface and inside, thereby avoiding the problem of a clear interface between the strengthening layer and the matrix layer. In addition, a large number of studies have shown that the surface gradient nanocrystalline structure can significantly improve the strength and plasticity of the metal, thereby achieving a synergistic effect of strength and plasticity. Not only that, since damage such as wear and corrosion usually occurs first on the metal surface, the surface gradient nanocrystalline structure can effectively improve the hardness of the metal, thereby reducing the hazards such as wear and corrosion. Through the principle of large surface plastic deformation, large plastic deformation can be performed on the metal surface to achieve a gradient nanostructure with refined grains at the nanoscale. Although there are various methods and techniques for large plastic deformation, due to the special shape of the pipe, there are not many technologies that can perform large surface plastic deformation on the pipe. The existing technologies for forming a gradient nanocrystalline structure on the surface of the pipe through large plastic deformation include shot peening and pulse impact technology, but due to the limitations of shot peening intensity and impact strength, under normal circumstances, the gradient nanocrystalline structure produced on the surface of the metal pipe is not obvious, the strengthening layer is thin, the strengthening effect is poor, and the comprehensive performance and service life of the metal pipe are not improved much. 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 impossible 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 preparing the gradient nanostructure 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 a metal pipe. The device structure and preparation process are simple, and gradient nanostructures can be prepared on the inner and outer walls of a metal pipe at the same time with 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 tube, comprising a mounting platform, on which a first fixing device, a tube outer wall rolling device and a second fixing device are sequentially arranged, the first fixing device is provided with a tube rotating device, the first fixing device reciprocates relative to the tube outer wall rolling device, the second fixing device is provided with a tube fixing device and a tube inner wall rolling device; the tube outer wall rolling device comprises a first telescopic device, a tube outer wall rolling tool is arranged at the front end of a first telescopic rod of the first telescopic device, the tube inner wall rolling device comprises a second telescopic device, a third telescopic device is arranged at the front end of a second telescopic rod of the second telescopic device, a tube inner wall rolling tool is arranged at the front end of the third telescopic rod of the third telescopic device, and the tube outer wall rolling tool and the tube inner wall rolling tool are 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, 10μm≤H≤100μm.

[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 tube 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 comprises a tool holder and a spherical blade, the tool holder is provided with a spherical groove matched with the spherical blade, and 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 a gradient nanostructure 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 working, 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, and 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, 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, and setting the pressing depth of the tube inner wall rolling tool, and the tube outer wall rolling tool and the tube inner wall rolling tool are arranged relative to each other;

[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, the tube outer wall rolling tool presses down the outer wall of the metal tube to plastically deform, and the tube inner wall rolling tool presses down the inner wall of the metal tube to plastically deform;

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

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

[0022] The present application provides a device for preparing gradient nanostructures on the inner and outer walls of a metal pipe, which is used for preparing gradient nanostructures on the inner and outer walls of a metal pipe. The device comprises a mounting platform, a first fixing device, a pipe rotating device, a first telescopic device, a pipe outer wall rolling tool, a second fixing device, a pipe fixing device, 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 use costs. When preparing gradient nanostructures on the inner and outer walls of a metal tube, the two ends of the metal tube are respectively fixed on a tube rotating device and clamped on a tube fixing device, the first telescopic device works, the first telescopic rod extends to make the tube outer wall rolling tool contact with the outer wall of the metal tube and press down to a designed depth; the second telescopic device works, the second telescopic rod extends to drive the third telescopic device to extend into the metal tube, and the tube outer wall rolling tool is arranged opposite to the tube inner wall rolling tool; the third telescopic device works, the third telescopic rod extends, so that the tube inner wall rolling tool contact with the inner wall of the metal tube and press down to a designed depth; the tube rotating device works and rotates to drive the metal tube to rotate, and the tube outer wall rolling tool radially mechanically presses the outer wall of the metal tube Rolling, the outer wall of the metal tube undergoes radial large plastic deformation to form a gradient nanostructure, the inner wall rolling tool of the tube mechanically rolls the inner wall of the metal tube radially, and the inner wall of the metal tube undergoes radial large plastic deformation to form a gradient nanostructure; at the same time, the first fixing device reciprocates relative to the outer wall rolling device of the tube, the outer wall rolling tool of the tube mechanically rolls the outer wall of the metal tube axially, and the outer wall of the metal tube undergoes axial large plastic deformation to form a gradient nanostructure, the inner wall rolling tool of the tube mechanically rolls the inner wall of the metal tube axially, and the inner wall of the metal tube undergoes axial large plastic deformation to form a gradient nanostructure, and the inner and outer walls of the metal tube are prepared with gradient nanostructures at the same time, improving the efficiency of preparing gradient nanostructures on the inner and outer walls of the metal tube. The preparation process of 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 mechanical rolling 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 the gradient nanostructure of the inner and outer walls of the metal pipe provided in the present application can not only prepare the gradient nanostructure on the inner and outer walls of the metal pipe at the same time, but also prepare the gradient nanostructure on the outer wall of the metal pipe alone, and can also prepare the gradient nanostructure 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 tube based on an apparatus for preparing gradient nanostructures on the inner and outer walls of a metal tube, which can simultaneously prepare gradient nanostructures on the inner and outer walls of a metal tube 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0024] Figure 1 It is a schematic diagram of preparing a gradient nanostructure on a metal tube by using a device for preparing a gradient nanostructure on the inner and outer walls of a metal tube provided by an embodiment of the present invention;

[0025] Figure 2 It is a state diagram of the tube inner wall rolling tool and the tube outer wall rolling tool provided in the embodiment of the present invention preparing a gradient nanostructure on a metal tube;

[0026] Figure 3 is a schematic structural diagram of a spherical tool provided by an embodiment of the present invention;

[0027] Figure 4 It is a 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 It is a schematic diagram of a gradient nanostructure prepared by a device for preparing a gradient nanostructure on the inner and outer walls of a metal pipe provided in 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 seat 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 described embodiments 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 creative work are within the scope of protection of the present invention.

[0031] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[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 an installation 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 reciprocates 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, a tube outer wall rolling tool 16 is arranged at the front end of a first telescopic rod 17 of the first telescopic device 18, the tube inner wall rolling device comprises a second telescopic device 11, a third telescopic device 9 is arranged at the front end of a second telescopic rod 10 of the second telescopic device 11, a tube inner wall rolling tool 7 is arranged at the front end of a third telescopic rod 8 of the third telescopic device 9, and the tube outer wall rolling tool 16 is arranged relative to the tube inner wall rolling tool 7 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 air cylinders. The pipe rotating device 4 is a disc with side guards, and the side guards of the disc are evenly provided with at least three push rods in the circumferential direction. The push rods are provided along the radial direction of the disc, and the side guards are provided with screw holes matched with the push rods. The push rods are threadedly connected with the side guards. The left end of the metal pipe 6 is placed in the disc, and the push rods are tightened to press against the outer wall of the metal pipe 6 to fix the metal pipe 6 to the disc. The disc is connected to the output shaft of the motor, and the motor starts the output shaft to rotate to drive the disc to rotate, and drive the metal pipe 6 to rotate; the first fixing device 3 reciprocates relative to the rolling device of the outer wall of the pipe under the action of the slider guide mechanism or the screw mechanism or the hydraulic cylinder or the air cylinder; or when the factory has a lathe or a drilling machine, the lathe or the drilling machine has a rotating device and a horizontal moving device, and the left end of the metal pipe 6 is fixed on the rotating device of the lathe or the drilling machine, and this rotating device can be used as the pipe rotating device 4, and the lathe or the 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 for preparing 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 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 is a metallographic image of the base layer structure of the metal tube 6. It is composed of an installation 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 device has a simple structure and low manufacturing and use costs. 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). The first telescopic device 18 works, and the first telescopic rod 17 of the first telescopic device 18 extends to make the tube outer wall rolling tool 16 abut against the outer wall of the metal tube 6 and press down to the designed depth (the depth of preparing the gradient nanostructure); the second telescopic device 11 works, and the second telescopic device 18 is extended to the outer wall rolling tool 16 of the metal tube 6. The second telescopic rod 10 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 partially plastically deformed in the radial direction to form a gradient nanostructure, and the inner wall of the tube 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 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 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 plastic deformation in the axial direction to form a gradient nanostructure, and at the same time, the metal tube is completed. The gradient nanostructures are prepared on the inner and outer walls of the metal tube 6, and the efficiency of preparing the gradient nanostructures on the inner and outer walls of the metal tube 6 is improved. For example, if the same gradient nanostructures are prepared on the inner and outer walls of the metal tube 6, the existing device needs to prepare the gradient nanostructure on the outer wall of the metal tube 6 first, and then prepare the gradient nanostructure on the inner wall of the metal tube 6. However, the device for preparing the gradient nanostructures on the inner and outer walls of the metal tube 6 can simultaneously prepare the gradient nanostructures on the inner and outer walls of the metal tube 6, and the cycle of preparing the gradient nanostructures on the inner and outer walls of the metal tube 6 is halved, which greatly improves the efficiency of preparing the gradient nanostructures on the inner and outer walls of the metal tube 6. The preparation process of the gradient nanostructures on the inner and outer walls of the metal tube 6 is simple, efficient, and low-cost, and can complete the preparation of the gradient nanostructures on the inner and outer walls of the metal tube 6 at a low cost and high efficiency.The gradient nanostructure of the inner and outer walls of the metal tube 6 formed by mechanical rolling 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 tube 6, thereby improving the quality of the gradient nanostructure of 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 nanostructure of the inner and outer walls of the metal tube 6 is uniformly prepared, and the inner and outer walls of the metal tube 6 simultaneously produce grain refinement, further improving the quality of the gradient nanostructure of 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 the gradient nanostructure of the inner and outer walls of the metal tube provided in this embodiment can not only prepare the gradient nanostructure of the inner and outer walls of the metal tube 6 at the same time, but also prepare the gradient nanostructure of the outer wall of the metal tube 6 alone, and can also prepare the gradient nanostructure of the inner wall of the metal tube 6 alone, 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, and is 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, a second telescopic device base 13 is provided on the second fixing device 14, the hydraulic cylinder of the first telescopic device 18 is installed on the first telescopic device base 19, and the hydraulic cylinder of the second telescopic device 11 is installed 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 outer wall and inner wall corresponding to 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 or 20μm or 50μm or 80μm or 100μm.

[0038] As an implementation 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 tube 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 the slider through a connecting rod mechanism. The motor is externally connected to a power supply, and the motor is electrically connected to a 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 metal pipes 6 of different lengths to form a gradient nanostructure.

[0040] As an implementation 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 , and 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 up along the second slide rail 5, and the tube fixing device 12 and the second telescopic device 11 move up along the third slide rail 15; when the diameter of the metal tube 6 is small, the tube rotating device 4 moves down along the second slide rail 5, and the tube fixing device 12 and the second telescopic device 11 move down along the third slide rail 15. The axial local large plastic deformation of the inner and outer walls of the metal tubes 6 with different diameters is achieved 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 the slider through a connecting rod mechanism. The motor is externally connected to a power supply, and the motor is electrically connected to a 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 on the second slide rail 5, 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 sliders that slide with the third slide rail 15, and the corresponding motors are connected to the corresponding sliders through a connecting rod mechanism. The motor is externally connected to a power supply, and the motor is electrically connected to a 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, the motor is electrically connected to the controller, and the controller controls the motor to start or stop.

[0042] As an implementation 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 tube outer wall rolling tool 16 and the tube inner wall rolling tool 7 for mechanical rolling, which reduces damage to the inner and outer walls of the metal tube 6, ensures a smooth mechanical rolling process, makes the gradient nanostructure formed on the inner and outer walls of the metal tube 6 more uniform, improves the quality of the gradient nanostructure on the inner and outer walls of the metal tube 6, and improves the comprehensive performance and service life of the metal tube 6.

[0044] As an implementation 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 matched with the spherical blade 202, and 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 the spherical blade 202 extends out of the groove edge of the spherical groove. It has a simple structure and low manufacturing and maintenance costs.

[0046] As an implementation 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 implementation method, Figure 3 As shown, a rubber ring 22 is provided at the groove edge of the spherical groove.

[0049] The rubber ring 22 arranged at the groove edge of the spherical groove plays a sealing role, which can prevent the lubricating oil or grease from flowing out, ensure that the spherical blade 202 runs smoothly in the blade seat 201 for a long time, and reduce the wear of the spherical blade 202 and the blade seat 201.

[0050] As an implementation method, Figure 4As shown, a protective cover 23 is provided on the mounting platform 1, and 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 in the protective cover 23. The protective cover 23 is provided with a medium injection port 24 for injecting a low-temperature medium. For example, the refinement effect of nickel alloy is more obvious at low temperature, and the nickel alloy pipe can produce a thicker strengthening layer at low temperature. When preparing a gradient nanostructure for the nickel alloy pipe, a low-temperature medium such as liquid nitrogen and liquid hydrogen is injected from the medium injection port 24. Further, an electromagnetic induction coil, laser heating, etc. can be arranged in the protective cover 23 to heat and increase the temperature of the metal pipe 6. For example, magnesium alloy is difficult to deform at low temperature, and a certain temperature (such as 200°C) is required 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 tube, and a device for preparing gradient nanostructures on the inner and outer walls of a metal tube 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 work, the first telescopic rod 17 of the first telescopic device 18 extends, 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 extends, 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 extends, 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;

[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, 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;

[0055] S4, repeat step S3 until the outer wall and the inner wall of the metal tube 6 complete the preparation of the 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 the gradient nanostructure on the outer wall of the metal tube 6 or the inner wall of the metal tube 6 or the inner and outer walls of the metal tube 6 at the same time. The preparation process has few steps and is simple to operate. The gradient nanostructure can be prepared on the inner and outer walls of the 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 the metal tube 6 and improving the comprehensive performance and service life of the metal tube 6.

[0057] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope 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 tube outer wall rolling device and a second fixing device (14) in sequence; the first fixing device (3) is provided with a tube rotating device (4); the first fixing device (3) reciprocates 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); a tube outer wall rolling tool (16) is provided at the front end of a first telescopic rod (17) of the first telescopic device (18); the tube inner wall rolling device comprises a second telescopic device (11); a third telescopic device (9) is provided at the front end of a second telescopic rod (10) of the second telescopic device (11); a tube inner wall rolling tool (7) is provided at the front end of a third telescopic rod (8) of the third telescopic device (9); 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 a gradient nanostructure.

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 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.

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 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 tube outer wall rolling device.

5. 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 fixing device (3) is provided with a second slide rail (5), and 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), and the pipe fixing device (12) and the second telescopic device (11) move along the third slide rail (15).

6. 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).

7. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 6, 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.

8. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 7, characterized in that: A lubricating layer (21) is provided between the inner wall of the spherical groove and the spherical blade (202).

9. The device for preparing gradient nanostructures on the inner and outer walls of a metal pipe according to claim 8, characterized in that: A rubber ring (22) is arranged at the groove edge of the spherical groove.

10. 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 9 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), 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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