A two-end expanded diameter special-shaped seamless steel pipe and its production equipment and method

Abstract

The invention discloses a seamless steel pipe with expanded diameter at both ends and a special-shaped steel pipe and a production device and method thereof. The steel pipe components include: B, Cu, Ti, Al, Cr, Ni, Mn, and Fe. The steel pipe body is a circular pipe with spatial bending, and the two ends of the steel pipe are provided with expanded diameter special-shaped joints, and the joints are embedded with anti-corrosion linings. The production steps of the pipe blank include: batching and smelting, vacuum refining, and continuous casting. The processing steps of the pipe blank include: hole expansion and shaping, and center bending. The processing equipment includes a base, and the top surface of the base is provided with a clamping mechanism that can move horizontally and vertically. The clamping mechanism sends the steel pipe in the material holding rack to the pipe expansion and shaping mechanisms on both sides of the base for processing, and then the processed steel pipe is rotated, lifted, and horizontally moved to the bending mechanism for bending through a transfer mechanism. The invention solves the problems of corrosion protection and spatial bending of special-shaped pipe joints by adding lining to the special-shaped expanded pipes at both ends of the special circular pipe.

Description

Technical Field

[0001] The invention relates to the technical field of seamless steel pipe production and processing equipment, and in particular to a seamless steel pipe with expanded diameters at both ends and a production device and method thereof. Background Art

[0002] When transporting fossil fuels or chemical materials such as petroleum and natural gas, the corrosive elements (such as S, etc.) contained in them are likely to cause corrosion to steel pipelines. The use of special inner-coated seamless steel pipes can prevent these elements from corroding the inner wall of the steel pipe, thereby increasing the service life of the transport pipeline. However, since most existing pipelines are connected by welding, the high temperature generated by welding can easily damage the anti-corrosion layer of the inner wall, which makes the welds of the pipelines very susceptible to corrosion, especially in some special equipment, where special-shaped pipelines are used for transportation. These pipelines are extremely difficult to weld and cannot be bent in complex spaces. They are very inconvenient to connect, which seriously affects the transportation efficiency. In actual use, the two ends of the seamless steel pipe can be expanded and then punched into special-shaped pipes for docking, while the circular middle section of the steel pipe is bent in space. There is no equipment in the prior art that can automatically complete the expansion, punching and bending, and manual transfer is required, which is very inconvenient. In addition, the steel pipe material used for processing needs to have both mechanical properties and corrosion resistance, while the traditional seamless steel pipe has poor corrosion resistance. A new type of steel pipe and supporting production equipment and methods are needed to solve the above problems. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes a seamless steel pipe with expanded diameters at both ends, wherein the steel pipe contains the following components: B: 0.05-0.08wt%; Cu: 0.2-0.24wt%; Ti: 0.3-0.4wt%; Al: 0.7-0.9wt%; Cr: 1.9-2.1wt%; Ni: 2.4-2.8wt%, Mn: 6.0-8.0wt%, and the remainder is iron. The steel pipe body is a circular pipe bent in space, and both ends of the steel pipe are expanded special-shaped joints, and anti-corrosion linings are embedded in the joints.

[0004] Furthermore, the diameter of the steel pipe after expansion is 1.15-1.6 times of the original diameter, the cross-sectional shape of the special-shaped joint is a regular polygon, and the distance between the first bending point of the steel pipe and the pipe end is more than 1.5 times the length of the special-shaped joint.

[0005] The present invention proposes production equipment for the above-mentioned steel pipe, including a base, a pair of pipe expanding mechanisms and shaping mechanisms are arranged on both sides of the base, the electric horizontal rail on the top surface of the base is connected to the longitudinal movement table, the electric vertical rail on the top surface of the longitudinal movement table is connected to the clamping mechanism, the input end of the longitudinal movement table is located below the output port of the material holding rack, the output end of the longitudinal movement table is located above the horizontal seat at the end of the base, the horizontal electric rail on the top surface of the horizontal seat is connected to the transfer mechanism, the transfer mechanism is connected to the steel pipe clamped by the clamping mechanism through the output shaft of the docking motor, and can rotate, lift and move the steel pipe horizontally to the bending mechanism.

[0006] Furthermore, the tube expansion mechanism includes a cylinder, the rear end of the cylinder is connected to the extrusion cylinder, the output end of the extrusion cylinder is connected to the bottom surface of the conical rod, the conical rod is slidably connected to the inner cylinder channel of the cylinder, the head end of the inner cylinder channel is a lifting groove evenly distributed in an annular pattern, the conical surface of the conical rod cooperates with the bottom surface of the petal block, and several petal blocks are assembled into a complete column. The expanded diameter end of the petal block is stepped, and the lifting end of the petal block is slidably connected to the lifting groove. The positioning column on the top surface of the lifting end is inserted into the reset spring, and the reset spring is embedded in the positioning hole on the top of the lifting groove. The flange at the head end of the cylinder is connected to the ring cover, and the middle connecting section of the petal block is slidably connected to the sliding groove radially opened in the ring cover.

[0007] Furthermore, the shaping mechanism includes a shell, the rear end of the shell is connected to the propulsion cylinder, the piston at the output end of the propulsion cylinder is slidably connected to the inner cavity of the shell, a number of slope blocks are evenly distributed on the edge of the piston end face, and the head end of the shell wall is evenly ringed with a number of through grooves opened to the inner cavity, a stamping block is slidably connected in the through groove, the inner slope of the stamping block cooperates with the slope block, the bottom slot of the stamping block is connected to the shaping mold, the bottom surface of the pressure plate at the top of the stamping block is connected to the inner bottom surface of the through groove through a spring, and the shell is connected to the sleeve through a flange, and the sleeve covers the opening at the top of the through groove.

[0008] Furthermore, the clamping mechanism includes a clamping cylinder, the cylinder body of the clamping cylinder is embedded in the clamping seat, the output end of the clamping cylinder is connected to the clamping plate, the lower side of the clamping plate is slidably connected to the support rod of the clamping claw, the support rod is connected to the end face of the clamping seat, the slider on the bottom surface of the clamping seat is threadedly connected to the first screw of the electric longitudinal rail, the two ends of the first screw are rotationally connected to the longitudinal groove on the top surface of the longitudinal movement platform, one end of the first screw is connected to the longitudinal movement motor at the end of the longitudinal movement platform, the slider on the bottom surface of the longitudinal movement platform is connected to the second screw of the electric transverse rail, the two ends of the second screw are rotationally connected to the transverse groove on the top surface of the base, and one end of the second screw is connected to the transverse movement motor on one side of the base.

[0009] Furthermore, the transfer mechanism includes an electric turntable, the top surface of the electric turntable is connected to the docking motor, the bottom surface of the electric turntable is connected to the output end of the lifting cylinder, the cylinder body of the lifting cylinder is embedded in the sliding seat, the two ends of the sliding seat are threadedly connected to the third screw, the two ends of the third screw are rotatably connected to the transverse groove on the top surface of the cross seat, and one end of the third screw is connected to the transverse motor at the end of the cross seat.

[0010] Furthermore, the bending mechanism includes a bending plate, a sliding seat on the inner end surface of the bending plate is slidably connected to the longitudinal groove on the end surface of the cross seat, a longitudinal motor is provided at one end of the longitudinal groove, an output screw of the longitudinal motor is rotationally connected to the other end of the longitudinal groove, the output screw is threadedly connected to the sliding seat, a convex seat is provided on one side of the outer end surface of the bending plate, a bending motor is embedded in the convex seat, the output end of the bending motor is vertically connected to the head end of the bending arm, a bending disk is provided on the top surface of the head end of the bending arm, a first clamping cylinder pointing to the bending disk is provided on the top surface of the end of the bending arm, the top surface of the cross seat is laterally connected to the extension cylinder, the output end of the extension cylinder is outwardly connected to the cylinder body of the second clamping cylinder, the base of the second clamping cylinder is slidably connected to the top surface of the cross seat, and when the bending arm and the bending plate are in fit, the two clamping cylinders are parallel and in the same direction.

[0011] Furthermore, the base is connected to the base plate on both sides, and a plurality of bolt grooves are longitudinally opened on the top surface of the base plate. The bolt grooves are slidably connected to the bolt heads, and the bolt rods are connected to the fastening nuts after passing through the base plate. The center of the base plate is connected to the cylinder body of the vertical cylinder, and the output end of the vertical cylinder is vertically connected to the corresponding pipe expansion mechanism and shaping mechanism upward; the material holding rack is a ramp rack, and the input port above the slope is connected to the conveyor belt, and the output port below the slope is provided with a material blocking cylinder, and the side wall of the material holding rack is threadedly connected to a plurality of pitch adjusting screws, the outer end of the pitch adjusting screw is connected to the adjusting disk, and the inner end of the pitch adjusting screw is rotatably connected to the pitch adjusting plate.

[0012] The present invention also provides a method for producing the steel pipe, comprising the following steps:

[0013] Batching smelting: put the batch into the induction furnace for smelting, use ferromanganese and aluminum deoxidation process for deoxidation, take samples and mix when the temperature reaches 1520-1560℃, tap the steel into the ladle when the temperature reaches 1620-1640℃, then carry out refining outside the furnace, control the slag basicity at 3.0-3.2, quickly make white slag, keep the white slag for more than 18 minutes, and put FeTi into the furnace for micro-titanium treatment;

[0014] Vacuum refining: control the vacuum degree below 57Pa for 14-15min, and soft blow argon for 5-7min after refining. Do not expose the molten steel. The VD tapping temperature is 1575-1595℃;

[0015] Continuous casting: The round billet is continuously cast using argon protection pouring and horizontal drawing speed control technology. The round billet is sent to a high-temperature furnace for heating and sawing into a fixed length. After hot centering, perforation and tube rolling, it is cooled and stored;

[0016] Hole expansion and shaping: The steel pipes in the warehouse are transported to the material rack via the conveyor belt. The steel pipes fall from the slope to the output port in turn. The material blocking cylinder shrinks the output end, and the steel pipe falls onto the clamping claw. The clamping cylinder is started to push the clamping plate to clamp the steel pipe. The longitudinal motor is started to move the steel pipe between the two pipe expansion mechanisms. The transverse motor is started to insert one end of the steel pipe into the column composed of the petal blocks on one side. The extrusion cylinder is started to radially squeeze the petal blocks. The petal blocks overcome the return spring sliding to expand the steel pipe. The two ends of the steel pipe are expanded in turn and then moved between the two shaping mechanisms, and then inserted into the inner mold columns on both sides in turn. The propulsion cylinder is started to drive the stamping block to overcome the spring and move to the inner cavity, and then the shaping molds move to shape the steel pipe.

[0017] Center bending: move one end of the steel pipe after hole expansion and shaping to face the output shaft of the docking motor, start the transverse motor to insert the output shaft into the steel pipe, and the clamping mechanism simultaneously releases the steel pipe. The electric turntable and the lifting cylinder cooperate to lift and rotate the steel pipe to the bending mechanism. The transverse motor moves the steel pipe horizontally to select each bending point, and the docking motor rotates the steel pipe to select the bending direction of each bending point. Start the longitudinal motor to make the bending disk fit one side of the steel pipe, start the two clamping cylinders to make the clamping block fit the other side of the steel pipe, and start the bending motor to rotate the bending arm for bending. The bending amplitude is controlled by the rotation angle.

[0018] The beneficial effects of the present invention are as follows: the specially made round tube in the present invention has good corrosion resistance and processability, and can be connected to special-shaped pipelines of different shapes by means of special-shaped expansion and lining at both ends, eliminating the complicated welding process and achieving good anti-corrosion effect; the middle section of the steel pipe is a round tube, which is easy to bend into various spatial shapes, convenient for pipeline connection, and has extremely high applicability; the production equipment proposed in the invention is highly integrated and can automatically complete the feeding, expansion, stamping and bending processes of the tube blank, thereby reducing labor costs and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a front view structural schematic diagram of the present invention;

[0020] Figure 2 It is a schematic diagram of the top view structure of the present invention;

[0021] Figure 3 It is a left-side structural schematic diagram of the present invention;

[0022] Figure 4 It is a right view structural schematic diagram of the present invention;

[0023] Figure 5 It is a front view structural diagram of the pipe expansion mechanism in the present invention;

[0024] Figure 6 It is a side structural diagram of the pipe expansion mechanism in the present invention;

[0025] Figure 7 It is a front view structural diagram of the shaping mechanism in the present invention;

[0026] Figure 8 It is a side structural diagram of the shaping mechanism in the present invention.

[0027] The reference numerals are as follows: 1. base; 101. horizontal seat; 102. horizontal groove; 103. horizontal groove; 104. longitudinal groove; 2. longitudinal moving platform; 201. longitudinal groove; 3. material rack; 301. pitch adjusting screw; 302. adjusting plate; 303. pitch adjusting plate; 4. docking motor; 5. steel pipe; 6. cylinder; 601. inner cylinder channel; 602. lifting groove; 7. extrusion cylinder; 8. cone rod; 9. petal block; 901. expansion end; 902. lifting end; 903. connecting section; 10. return spring; 11. ring cover; 1101. slide groove; 12. shell; 1201. inner cavity channel; 1202. through groove; 13. propulsion cylinder; 1301. piston; 1302. slope block; 1303. inner mold column; 14. stamping block; 1401. inner slope surface; 14 02. Pressing plate; 15. Shaping mold; 16. Spring; 17. Sleeve; 18. Clamping cylinder; 19. Clamping seat; 20. Clamping plate; 21. Clamping claw; 22. First screw; 23. Longitudinal motor; 24. Second screw; 25. Transverse motor; 26. Electric turntable; 27. Lifting cylinder; 28. Sliding seat; 29. ​​Third screw; 30. Transverse motor; 31. Bending plate; 3101. Sliding seat; 3102. Boss seat; 32. Longitudinal motor; 3201. Output screw; 33. Bending motor; 34. Bending arm; 35. Bending plate; 36. First clamping cylinder; 37. Extension cylinder; 38. Second clamping cylinder; 39. Base plate; 3901. Bolt slot; 40. Base plate; 41. Vertical cylinder; 42. Conveyor belt; 43. Blocking cylinder. DETAILED DESCRIPTION

[0028] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The present invention will be further described below in conjunction with the accompanying drawings:

[0031] The present invention firstly proposes a double-end expanded diameter special-shaped seamless steel pipe, which comprises the following components: B: 0.05-0.08wt%; Cu: 0.2-0.24wt%; Ti: 0.3-0.4wt%; Al: 0.7-0.9wt%; Cr: 1.9-2.1wt%; Ni: 2.4-2.8wt%, Mn: 6.0-8.0wt%, and the balance is iron, wherein the solid solution strengthening effect of the B element can effectively resist high temperature deformation and damage while improving the hardenability of the alloy elements, and further Improve the mechanical properties of the steel pipe; Cu5FeS4 and other compounds formed by the Cu element in the steel can improve the corrosion resistance and significantly enhance the strength and hardness of the steel pipe; TiC formed by the Ti element has extremely strong stability, which can refine the grains to prevent intergranular corrosion, and at the same time improve the welding performance and prevent overheating tendency; Al element can enhance the corrosion resistance of the steel pipe surface, and at the same time refine the grains to improve the mechanical properties of the steel; Cr and Ni elements can enhance the strength and toughness of high manganese steel while improving the corrosion resistance of manganese steel. The above element ratio can effectively improve the corrosion resistance of seamless steel pipes, while also having mechanical properties. Its elongation is 32-35%, which meets the requirements of diameter expansion and stamping shaping. The steel pipe body is a circular pipe with spatial bending, and the two ends of the steel pipe are special-shaped joints after the diameter expansion. The anti-corrosion lining is embedded in the joint. The diameter of the steel pipe after expansion is 1.15-1.6 times the original diameter. The cross-sectional shape of the special-shaped joint is a regular polygon. The distance from the first bending point of the steel pipe to the pipe end is more than 1.5 times the length of the special-shaped joint.

[0032] like Figures 1 to 8 As shown, the present invention proposes a production equipment for the above-mentioned steel pipe, including a base 1, a pair of pipe expanding mechanisms and shaping mechanisms arranged on both sides of the base 1 are located on a base plate 39, a plurality of bolt grooves 3901 are longitudinally opened on the top surface of the base plate 39, the bolt grooves 3901 are slidably connected to the bolt heads, the bolt rods pass through the seat plate 40 and are connected to the fastening nuts, the center of the seat plate 40 is connected to the cylinder body of the vertical cylinder 41, and the output end of the vertical cylinder 41 is vertically connected to the corresponding pipe expanding mechanism and shaping mechanism upward.

[0033] In this embodiment, the tube expansion mechanism includes a cylinder 6, the tail end of the cylinder 6 is connected to the extrusion cylinder 7, the output end of the extrusion cylinder 7 is connected to the bottom surface of the tapered rod 8, the tapered rod 8 is slidably connected to the inner cylinder channel 601 of the cylinder 6, the head end of the inner cylinder channel 601 is a lifting groove 602 evenly distributed in an annular pattern, the tapered surface of the tapered rod 8 cooperates with the bottom surface of the petal block 9, and several petal blocks 9 are assembled into a complete column. The expanded diameter end 901 of the petal block 9 is stepped, and the lifting end 902 of the petal block 9 is slidably connected to the lifting groove 602. The positioning column on the top surface of the lifting end 902 is inserted into the reset spring 10, and the reset spring 10 is embedded in the positioning hole at the top of the lifting groove 602. The flange at the head end of the cylinder 6 is connected to the ring cover 11, and the middle connecting section 903 of the petal block 9 is slidably connected to the slide groove 1101 radially opened by the ring cover 11. When the extrusion cylinder 7 pushes the cone rod 8 outward, the conical surface of the cone rod 8 can push the petals 9 to spread radially, thereby expanding the diameter of the assembled column. The stepped petals 9 can adapt to steel pipes 5 with different inner diameters, making the diameter expansion more uniform.

[0034] In this embodiment, the shaping mechanism includes a shell 12, the rear end of the shell 12 is connected to the propulsion cylinder 13, the piston 1301 at the output end of the propulsion cylinder 13 is slidably connected to the inner cavity 1201 of the shell 12, and a number of slope blocks 1302 are evenly distributed on the edge of the end face of the piston 1301. The front end of the shell wall of the shell 12 is evenly annularly provided with a number of through grooves 1202 opened to the inner cavity 1201. The through groove 1202 is slidably connected to the punching block 14, and the inner slope 1401 of the punching block 14 cooperates with the slope block 1302. The bottom slot of the punching block 14 is connected to the shaping mold 15, and the bottom surface of the top pressure plate 1402 of the punching block 14 is connected to the inner bottom surface of the through groove 1202 through a spring 16. The shell 12 is connected to the sleeve 17 through a flange, and the sleeve 17 covers the top opening of the through groove 1202. When the thrust cylinder 13 pushes the piston 1301 outward, the component force of the contact surface of the ramp block 1302 pushes the stamping block 14 to shrink toward the inner cavity 1201, thereby driving the shaping die 15 to stamp and shape the steel pipe 5.

[0035] In this embodiment, the electric transverse rail on the top surface of the base 1 is connected to the longitudinal moving platform 2, and the electric longitudinal rail on the top surface of the longitudinal moving platform 2 is connected to the clamping mechanism. The clamping mechanism includes a clamping cylinder 18, and the cylinder body of the clamping cylinder 18 is embedded in the clamping seat 19. The output end of the clamping cylinder 18 is connected to the clamping plate 20, and the lower side of the clamping plate 20 is slidably connected to the support rod of the clamping claw 21, and the support rod is connected to the end surface of the clamping seat 19. The slider on the bottom surface of the clamping seat 19 is threadedly connected to the first screw 22 of the electric longitudinal rail, and the two ends of the first screw 22 are rotationally connected to the longitudinal groove 201 on the top surface of the longitudinal moving platform 2, and one end of the first screw 22 is connected to the longitudinal motor 23 at the end of the longitudinal moving platform 2, and the slider on the bottom surface of the longitudinal moving platform 2 is connected to the second screw 24 of the electric transverse rail, and the two ends of the second screw 24 are rotationally connected to the transverse groove 102 on the top surface of the base 1, and one end of the second screw 24 is connected to the transverse motor 25 on one side of the base 1. When the clamping cylinder 18 pushes the clamping plate 20 outward, the distance between the clamping plate 20 and the clamping claws 21 is reduced, thereby clamping the steel pipe 5.

[0036] In this embodiment, the input end of the longitudinal moving platform 2 is located below the output port of the material holding rack 3. The material holding rack 3 is a slope rack. The input port above the slope is connected to the conveyor belt 42, and the output port below the slope is provided with a material blocking cylinder 43. The side wall of the material holding rack 3 is threadedly connected to a plurality of distance adjusting screws 301. The outer end of the distance adjusting screw 301 is connected to the adjusting disk 302. The inner end of the distance adjusting screw 301 is rotatably connected to the distance adjusting plate 303. Rotating the adjusting disk 302 can change the spacing of the distance adjusting plates 303 to adapt to steel pipes 5 of different lengths. The output end of the longitudinal moving platform 2 is located above the horizontal seat 101 at the end of the base 1. The horizontal electric rail on the top surface of the horizontal seat 101 is connected to the transfer mechanism. The transfer mechanism includes an electric turntable 26. The top surface of the electric turntable 26 is connected to the docking motor 4. The bottom surface of the electric turntable 26 is connected to the output end of the lifting cylinder 27. The cylinder body of the lifting cylinder 27 is embedded in the sliding seat 28. The two ends of the sliding seat 28 are threadedly connected to the third screw 29. The two ends of the third screw 29 are rotatably connected to the horizontal groove 103 on the top surface of the horizontal seat 101. One end of the third screw 29 is connected to the horizontal motor 30 at the end of the horizontal seat 101. The transfer mechanism is connected to the steel pipe 5 clamped by the clamping mechanism through the output shaft of the docking motor 4, and can rotate, lift, and horizontally move the steel pipe 5 to the bending mechanism.

[0037] In this embodiment, the bending mechanism includes a bending plate 31, a sliding seat 3101 on the inner end surface of the bending plate 31 is slidably connected to the longitudinal groove 104 on the end surface of the horizontal seat 101, a longitudinal motor 32 is provided at one end of the longitudinal groove 104, an output screw 3201 of the longitudinal motor 32 is rotatably connected to the other end of the longitudinal groove 104, the output screw 3201 is threadedly connected to the sliding seat 3101, a convex seat 3102 is provided on one side of the outer end surface of the bending plate 31, and a bending motor 33 is embedded in the convex seat 3102, and the bending motor 33 is provided on the outer end surface of the bending plate 31. The output end of the bending arm 34 is vertically connected to the head end of the bending arm 34, the top surface of the head end of the bending arm 34 is provided with a bending plate 35, the top surface of the end of the bending arm 34 is provided with a first clamping cylinder 36 pointing to the bending plate 35, the top surface of the horizontal seat 101 is horizontally connected to the extension cylinder 37, the output end of the extension cylinder 37 is connected to the cylinder body of the second clamping cylinder 38 outwardly, the base of the second clamping cylinder 38 is slidably connected to the top surface of the horizontal seat 101, when the bending arm 34 is in contact with the bending plate 31, the two clamping cylinders are parallel and in the same direction. The bending motor 33 drives the bending arm 34 to rotate, which can bend the clamped steel pipe 5. During the bending process, the extension cylinder 37 provides a compensation distance for the second clamping cylinder 38, so that the second clamping cylinder 38 and the steel pipe 5 remain relatively still to avoid leaving scratches on the pipe body.

[0038] The present invention also provides a method for producing the steel pipe, comprising the following steps:

[0039] Batching smelting: put the batch into the induction furnace for smelting, use ferromanganese and aluminum deoxidation process for deoxidation, take samples and mix when the temperature reaches 1520-1560℃, tap the steel into the ladle when the temperature reaches 1620-1640℃, then carry out refining outside the furnace, control the slag basicity at 3.0-3.2, quickly make white slag, keep the white slag for more than 18 minutes, and put FeTi into the furnace for micro-titanium treatment;

[0040] Vacuum refining: control the vacuum degree below 57Pa for 14-15min, and soft blow argon for 5-7min after refining. Do not expose the molten steel. The VD tapping temperature is 1575-1595℃;

[0041] Continuous casting: The round billet is continuously cast using argon protection pouring and horizontal drawing speed control technology. The round billet is sent to a high-temperature furnace for heating and sawing into a fixed length. After hot centering, perforation and tube rolling, it is cooled and stored;

[0042] Hole expansion and shaping: The steel pipe 5 in the warehouse is transported to the material holding rack 3 via the conveyor belt 42. The steel pipe 5 falls from the slope to the output port in turn. The material blocking cylinder 43 shrinks the output end, and the steel pipe 5 falls onto the clamping claw 21. The clamping cylinder 18 is started to push the clamping plate 20 to clamp the steel pipe 5. The longitudinal movement motor 23 is started to move the steel pipe 5 between the two pipe expansion mechanisms. The transverse movement motor 25 is started to insert one end of the steel pipe 5 into the column composed of the petal blocks 9 on one side. The extrusion cylinder 7 is started to radially squeeze the petal blocks 9. The petal blocks 9 overcome the return spring 10 and slide to expand the diameter of the steel pipe 5. The two ends of the steel pipe 5 are expanded in turn and then moved between the two shaping mechanisms, and then inserted into the inner mold columns 1303 on both sides in turn. The propulsion cylinder 13 is started to drive the punching block 14 to overcome the spring 16 to move toward the inner cavity 1201, and then the shaping molds 15 are moved to shape the steel pipe 5.

[0043] Center bending: move one end of the expanded and shaped steel pipe 5 to face the output shaft of the docking motor 4, start the transverse motor 30 to insert the output shaft into the steel pipe 5, and the clamping mechanism simultaneously releases the steel pipe 5. The electric turntable 26 and the lifting cylinder 27 cooperate to lift and rotate the steel pipe 5 to the bending mechanism. The transverse motor 30 moves the steel pipe 5 laterally to select each bending point, and the docking motor 4 rotates the steel pipe 5 to select the bending direction of each bending point. Start the longitudinal motor 32 to make the bending disk 35 fit with one side of the steel pipe 5, start the two clamping cylinders to make the clamping block fit with the other side of the steel pipe 5, and start the bending motor 33 to rotate the bending arm 34 for bending. The bending amplitude is controlled by the rotation angle.

[0044] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A production device for a seamless steel pipe with expanded diameter at both ends, comprising a base (1), characterized in that: A pair of expansion mechanisms and shaping mechanisms are provided on both sides of the base (1), the shaping mechanism comprising a shell (12), the rear end of the shell (12) being connected to the propulsion cylinder (13), the output end piston (1301) of the propulsion cylinder (13) being slidably connected to the inner cavity (1201) of the shell (12), the end surface edge of the piston (1301) being evenly distributed with a plurality of slope blocks (1302), the front end of the shell wall of the shell (12) being evenly distributed with a plurality of openings to the inner cavity (1201), and the outer end of the shell wall of the shell (12) being evenly distributed with a plurality of openings to the inner cavity (1201). ) through a through slot (1202), the through slot (1202) is slidably connected to a punching block (14), the inner slope (1401) of the punching block (14) cooperates with the slope block (1302), the bottom slot of the punching block (14) is connected to the shaping die (15), the bottom surface of the top pressure plate (1402) of the punching block (14) is connected to the inner bottom surface of the through slot (1202) through a spring (16), the housing (12) is connected to a sleeve (17) through a flange, and the sleeve (17) covers To the open top of the through slot (1202), the electric horizontal rail on the top of the base (1) is connected to the longitudinal moving platform (2), the electric vertical rail on the top of the longitudinal moving platform (2) is connected to the clamping mechanism, the input end of the longitudinal moving platform (2) is located below the output port of the material holding rack (3), the output end of the longitudinal moving platform (2) is located above the end horizontal seat (101) of the base (1), the horizontal electric rail on the top of the horizontal seat (101) is connected to the lifting cylinder (27) of the transfer mechanism, and the lifting cylinder (27) is connected to the electric turntable (26 ) bottom surface, the output shaft of the docking motor (4) connected to the top surface of the electric turntable (26) can be connected to the steel pipe (5) clamped by the clamping mechanism, and can rotate, lift, and move the steel pipe (5) to the bending mechanism, the stretching cylinder (37) in the bending mechanism is laterally connected to the top surface of the horizontal seat (101), the output end of the stretching cylinder (37) is connected to the cylinder body of the second clamping cylinder (38) outwardly, and the base of the second clamping cylinder (38) is slidably connected to the top surface of the horizontal seat (101); The steel pipe comprises the following components: B: 0.05-0.08wt%; Cu: 0.2-0.24wt%; Ti: 0.3-0.4wt%; Al: 0.7-0.9wt%; Cr: 1.9-2.1wt%; Ni: 2.4-2.8wt%, Mn: 6.0-8.0wt%, and the balance is iron. The steel pipe body is a circular pipe bent in space, and both ends of the steel pipe are special-shaped joints after the diameter is expanded, and the anti-corrosion lining is embedded in the joint; The steel pipe is 1.15-1.6 times the original diameter after expansion, the cross-section of the special-shaped joint is a regular polygon, and the distance between the first bending point of the steel pipe and the pipe end is more than 1.5 times the length of the special-shaped joint.

2. The production equipment of a double-end expanded diameter special-shaped seamless steel pipe according to claim 1 is characterized in that: The tube expansion mechanism comprises a cylinder (6), the rear end of the cylinder (6) is connected to an extrusion cylinder (7), the output end of the extrusion cylinder (7) is connected to the bottom surface of a conical rod (8), the conical rod (8) is slidably connected to an inner tube channel (601) of the cylinder (6), the head end of the inner tube channel (601) is a lifting groove (602) evenly distributed in an annular pattern, the conical surface of the conical rod (8) is matched with the bottom surface of a petal block (9), a plurality of petals (9) are assembled into a complete column, and the expanded diameter end of the petal block (9) is (901) is in a stepped shape, the lifting end (902) of the petal block (9) is slidably connected to the lifting groove (602), the positioning column on the top surface of the lifting end (902) is inserted into the return spring (10), the return spring (10) is embedded in the positioning hole at the top of the lifting groove (602), the front end flange of the cylinder (6) is connected to the ring cover (11), and the middle connecting section (903) of the petal block (9) is slidably connected to the sliding groove (1101) radially opened on the ring cover (11).

3. The production equipment of a double-end expanded-diameter special-shaped seamless steel pipe according to claim 2 is characterized in that: The clamping mechanism comprises a clamping cylinder (18), the cylinder body of the clamping cylinder (18) is embedded in the clamping seat (19), the output end of the clamping cylinder (18) is connected to the clamping plate (20), the lower side of the clamping plate (20) is slidably connected to the support rod of the clamping claw (21), the support rod is connected to the end surface of the clamping seat (19), the bottom surface slider of the clamping seat (19) is threadedly connected to the first screw rod (22) of the electric longitudinal rail, the two ends of the first screw rod (22) are rotatably connected to the longitudinal groove (201) on the top surface of the longitudinal moving platform (2), one end of the first screw rod (22) is connected to the longitudinal moving motor (23) at the end of the longitudinal moving platform (2), the bottom surface slider of the longitudinal moving platform (2) is connected to the second screw rod (24) of the electric transverse rail, the two ends of the second screw rod (24) are rotatably connected to the transverse groove (102) on the top surface of the base (1), and one end of the second screw rod (24) is connected to the transverse moving motor (25) on one side of the base (1).

4. The production equipment of a double-end expanded-diameter special-shaped seamless steel pipe according to claim 3 is characterized in that: The cylinder body of the lifting cylinder (27) is embedded in the sliding seat (28), the two ends of the sliding seat (28) are threadedly connected to the third screw rod (29), the two ends of the third screw rod (29) are rotationally connected to the transverse groove (103) on the top surface of the transverse seat (101), and one end of the third screw rod (29) is connected to the transverse motor (30) at the end of the transverse seat (101).

5. The production equipment of the double-end expanded-diameter special-shaped seamless steel pipe according to claim 4 is characterized in that: The bending mechanism comprises a bending plate (31), a sliding seat (3101) on the inner end surface of the bending plate (31) being slidably connected to a longitudinal groove (104) on the end surface of a transverse seat (101), a longitudinal motor (32) being provided at one end of the longitudinal groove (104), an output screw (3201) of the longitudinal motor (32) being rotatably connected to the other end of the longitudinal groove (104), the output screw (3201) being threadedly connected to the sliding seat (3101), and the outer end of the bending plate (31) being connected to the longitudinal groove (104). A convex seat (3102) is provided on one side of the surface, a bending motor (33) is embedded in the convex seat (3102), an output end of the bending motor (33) is vertically connected to the head end of the bending arm (34), a bending plate (35) is provided on the top surface of the head end of the bending arm (34), and a first clamping cylinder (36) pointing to the bending plate (35) is provided on the top surface of the rear end of the bending arm (34), and when the bending arm (34) is in contact with the bending plate (31), the two clamping cylinders are parallel and in the same direction.

6. The production equipment of the double-end expanded-diameter special-shaped seamless steel pipe according to claim 5 is characterized in that: The base (1) is connected to a base plate (39) at both sides. The top surface of the base plate (39) is longitudinally provided with a plurality of bolt grooves (3901). The bolt grooves (3901) are slidably connected to bolt heads. The bolt rods pass through the base plate (40) and are connected to fastening nuts. The center of the base plate (40) is connected to the cylinder body of a vertical cylinder (41). The output end of the vertical cylinder (41) is vertically connected to the corresponding pipe expansion mechanism and shaping mechanism upward. The material holding rack (3) is a ramp rack. The input port above the ramp is connected to a conveyor belt (42). The output port below the ramp is provided with a material blocking cylinder (43). The side wall of the material holding rack (3) is threadedly connected to a plurality of pitch adjusting screws (301). The outer ends of the pitch adjusting screws (301) are connected to an adjusting disk (302). The inner ends of the pitch adjusting screws (301) are rotatably connected to a pitch adjusting plate (303).

7. A method for producing a steel pipe, using the steel pipe production equipment according to claim 6, characterized in that: The steps include: Batching smelting: put the batch into the induction furnace for smelting, use ferromanganese and aluminum deoxidation process for deoxidation, take samples and mix when the temperature reaches 1520-1560℃, tap the steel into the ladle when the temperature reaches 1620-1640℃, then carry out refining outside the furnace, control the slag basicity at 3.0-3.2, quickly make white slag, keep the white slag for more than 18 minutes, and put FeTi into the furnace for micro-titanium treatment; Vacuum refining: control the vacuum degree below 57Pa for 14-15min, and soft blow argon for 5-7min after refining. Do not expose the molten steel. The VD tapping temperature is 1575-1595℃; Continuous casting: The round billet is continuously cast using argon protection pouring and horizontal drawing speed control technology. The round billet is sent to a high-temperature furnace for heating and sawing into a fixed length. After hot centering, perforation and tube rolling, it is cooled and stored; Hole expansion and shaping: The steel pipe (5) in the warehouse is transported to the material rack (3) via the conveyor belt (42), and the steel pipe (5) falls from the slope to the output port in turn. The material blocking cylinder (43) contracts the output end, and the steel pipe (5) falls onto the clamping claw (21). The clamping cylinder (18) is started to push the clamping plate (20) to clamp the steel pipe (5). The longitudinal movement motor (23) is started to move the steel pipe (5) between the two expansion mechanisms. The transverse movement motor (25) is started to insert one end of the steel pipe (5) into the side petal block (9) to assemble. In the synthesized column, the extrusion cylinder (7) is started to radially squeeze out the petals (9), and the petals (9) overcome the return spring (10) to slide and expand the diameter of the steel pipe (5). The two ends of the steel pipe (5) are expanded in diameter and then moved between the two shaping mechanisms, and then inserted into the inner mold columns (1303) on both sides in turn. The propulsion cylinder (13) is started to drive the punching block (14) to overcome the spring (16) and move toward the inner cavity (1201), and then the shaping molds (15) move to shape the steel pipe (5); Center bending: one end of the steel pipe (5) after expansion and shaping is moved to face the output shaft of the docking motor (4), the transverse motor (30) is started to insert the output shaft into the steel pipe (5), the clamping mechanism simultaneously releases the steel pipe (5), and the steel pipe (5) is lifted and rotated to the bending mechanism through the cooperation of the electric turntable (26) and the lifting cylinder (27). The transverse motor (30) moves the steel pipe (5) laterally to select each bending point, the docking motor (4) rotates the steel pipe (5) to select the bending direction of each bending point, the longitudinal motor (32) is started to make the bending plate (35) fit with one side of the steel pipe (5), the two clamping cylinders are started to make the clamping block fit with the other side of the steel pipe (5), and the bending motor (33) is started to rotate the bending arm (34) to bend, and the bending range is controlled by the rotation angle.

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