An austenitic-ferritic super duplex stainless steel seamless pipe and a process for its production

Abstract

The application provides an austenitic ferritic super duplex stainless steel seamless pipe and a preparation process thereof, relates to the technical field of super duplex stainless steel seamless pipes, and comprises a seamless pipe body which is composed of an outer pipe piece, a reinforcing pipe piece and a heat insulation pipe piece. The high temperature possibly generated in oil and gas transportation is subjected to heat insulation treatment through the arrangement of the internal heat insulation pipe piece. The heat insulation pipe piece is based on polypropylene and polybutylene as base materials, and the strength and toughness thereof are ensured through reinforcing fibers and plasticizers. The heat insulation performance thereof is ensured through the arrangement of paraffin and modified calcium carbonate. Further, through the combination of defoaming agents and air entraining agents, large bubbles are removed and small molecule bubbles are introduced, so that the heat insulation performance of the heat insulation pipe piece is improved. Through the multi-sectioned angular arrangement of the reinforcing pipe piece, further support is provided to the outer pipe piece, so that the overall sealing performance and strength are ensured. Through the phased processing mode of the pretreatment stage and the shaping and cutting stage, the processing difficulty is reduced in cooperation with the plate processing device.

Description

Technical Field

[0001] This invention relates to the field of super duplex stainless steel seamless tube technology, and in particular to an austenitic ferritic super duplex stainless steel seamless tube and its preparation process. Background Technology

[0002] Austenitic-ferritic super duplex stainless steel seamless tubes are tubular structures made from S32750 alloy. They are typically used as core components in subsea oil and gas production systems. S32750 alloy is a super duplex stainless steel designed for applications requiring exceptional strength and corrosion resistance. Containing 25% chromium, 4% molybdenum, and 7% nickel, this high molybdenum, chromium, and nitrogen content results in excellent resistance to chloride pitting and crevice corrosion. The duplex structure gives S32750 excellent resistance to chloride stress corrosion cracking. [The last sentence appears to be incomplete and possibly refers to a different application:] ...undersea oil and gas production... The operating environment of the production system is characterized by high pressure on the seabed and harsh chloride corrosion, which means that the piping used in the deep-water central manifold must have high strength, high toughness, fatigue resistance, good weldability, seawater corrosion resistance, and good cold workability. The existing austenitic ferritic super duplex stainless steel seamless pipe made of S32750 alloy has excellent mechanical properties and can meet the environmental requirements. However, the high temperature that may be generated during internal oil and gas transportation will reduce the toughness and corrosion resistance of low alloy S32750, and the processing of duplex stainless steel is also more difficult, so improvements are needed. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and to propose an austenitic ferritic super duplex stainless steel seamless tube and its preparation process.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: an austenitic-ferritic super duplex stainless steel seamless tube, comprising a seamless tube body, wherein the seamless tube body is composed of an outer tube, a reinforcing tube, and a heat-insulating tube, wherein the reinforcing tube is located between the outer tube and the heat-insulating tube, and the reinforcing tube is fixedly connected to the outer tube and the heat-insulating tube, wherein the shape of the reinforcing tube is multi-segmented angled, and both ends of the seamless tube body are provided with butt grooves, wherein the seamless tube bodies are engaged with each other through the butt grooves.

[0005] As a further aspect of the present invention, the outer pipe fitting and the reinforcing pipe fitting are both made of S32750 alloy. The insulation pipe fitting is made of polypropylene, polybutene, paraffin wax, modified calcium carbonate, and reinforcing fiber. The reaction material of the insulation pipe fitting is made of plasticizer, stabilizer, antibacterial agent, defoamer, and air-entraining agent. Each material is composed of the following raw materials in parts by weight: 70-85 parts polypropylene, 530-35 parts polybutene, 2-5 parts paraffin wax, 6-12 parts modified calcium carbonate, 15-22 parts reinforcing fiber, 2-3 parts plasticizer, 3-5 parts stabilizer, 2-3 parts antibacterial agent, 5-10 parts defoamer, and 3-5 parts air-entraining agent.

[0006] A process for preparing seamless austenitic-ferritic super duplex stainless steel tubes includes the following steps:

[0007] S1: Material mixing and processing stage for thermal insulation pipe fittings;

[0008] S2: Place the pre-treatment material for the thermal insulation pipe fittings inside the container;

[0009] S3: The pre-treatment material for the thermal insulation pipe fitting is introduced into the tubular mold and cooled to form the thermal insulation pipe fitting.

[0010] S4: Reinforced pipe fitting preparation stage;

[0011] S5: Weld the two ends of the pre-treated plate to form a tubular structure and obtain a reinforced pipe;

[0012] S6: Assembly and forming stage.

[0013] As a further aspect of the present invention, the steps in the heat insulation pipe material mixing treatment stage of S1 specifically include:

[0014] S110: Add the material for preparing the heat insulation pipe fitting into the reaction furnace;

[0015] S120: Plasticizers and stabilizers are added into the prepared material in sequence;

[0016] S130: The material is heated in a reactor to bring it to a molten state, and then stirred and mixed.

[0017] S140: Maintain the temperature inside the reactor at 80℃ and continue stirring and mixing. Introduce the antibacterial agent and defoamer into the reactor and wait for 20 minutes.

[0018] S150: Stop stirring and wait for 30 minutes. At this time, the large air bubbles inside the material are fully discharged by the defoamer to obtain the pre-treatment material for heat insulation pipe fittings.

[0019] In S130, the temperature of the reactor heating treatment is 75℃-90℃, the reactor heating treatment method is step heating, the reactor heating treatment time is 25-30min, the stirring and mixing speed is 1200r / min, and the stirring and mixing time is 15min.

[0020] As a further aspect of the present invention, in step S2, the step of placing the heat insulation pipe pretreatment material inside the container specifically involves introducing the heat insulation pipe pretreatment material obtained in step S150 into the container and maintaining the temperature inside the container at 45°C, adding an air-entraining agent and stirring evenly, and waiting for the reaction to proceed for 15 minutes. At this time, small molecule bubbles are evenly introduced into the heat insulation pipe pretreatment material.

[0021] As a further embodiment of the present invention, in step S3, the reinforced pipe fitting preparation stage employs a plate processing device. This plate processing device comprises a pretreatment mechanism and a processing and shaping mechanism. The pretreatment mechanism includes a base plate, with a pre-processing table mounted on the front end of the base plate. A first-order folding frame is mounted on both sides of the upper surface of the pre-processing table. A first-order flipping frame is rotatably connected to the top of the first-order folding frame. An electric telescopic rod is rotatably connected between the first-order flipping frame and the first-order folding frame. Outer rings are mounted on both the upper and lower surfaces of the first-order flipping frame, and a drive shaft is rotatably connected between the outer rings. A drive motor is mounted on the side surface of the ring, and the output end of the drive motor is fixedly connected to the drive shaft. An oil tank is mounted at the center of the upper surface of the base plate, and a hose is mounted at the output end of the oil tank. A diverter pipe is mounted at one end of the hose, and a feed pipe is mounted at both ends of the diverter pipe. A support frame is mounted on the outer surface of the feed pipe, and flame heaters are equidistantly mounted on the outer surface of the feed pipe. A linkage shaft is rotatably connected between the support frame and the first tilting frame. An extension shaft is mounted at each of the four corners of the lower surface of the support frame, and a hollow cylinder is sleeved on the outer surface of the extension shaft. The hollow cylinder is fixedly connected to the base plate.

[0022] As a further embodiment of the present invention, the processing and shaping mechanism includes a post-processing table. Two angle-folding frames are mounted on both sides of the upper surface of the post-processing table. A second-stage tilting frame is rotatably connected to the top of the second-stage angle-folding frame. A second-stage electric telescopic rod is rotatably connected between the second-stage tilting frame and the second-stage angle-folding frame. Limiting rings are mounted on the upper and lower surfaces of the second-stage tilting frame. A shaping roller is rotatably connected between the limiting rings. The shaping roller is configured as a multi-segment angled cylinder. A shaping motor is mounted on the side surface of the limiting rings. The output end of the shaping motor is fixedly connected to the shaping roller. An adjusting shaft is rotatably connected to the rear end of the second-stage tilting frame. A sliding frame is rotatably connected to one end of the adjusting shaft. The sliding frame is slidably connected to the rear end of the second-stage angle-folding frame. A tool holder is mounted between the sliding frames. Hydraulic rods are mounted on the side surfaces of the two sets of sliding frames. A hot-cutting blade is mounted at the output end of the hydraulic rod, and the hot-cutting blade is located above the tool holder.

[0023] As a further aspect of the present invention, in step S4, the reinforced pipe preparation stage includes a pretreatment stage and a shaping and cutting stage, wherein the steps of the pretreatment stage are as follows:

[0024] S411: By operating the No. 1 and No. 2 electric telescopic rods, the angles of the No. 1 angle-folding frame and the No. 2 tilting frame are adjusted in opposite directions, thereby limiting the input and output trajectories of the S32750 alloy plate;

[0025] S412: During the angle adjustment process of the No. 1 electric telescopic rod driving the No. 1 angle frame, the height of the support frame is adjusted through the linkage shaft, and the movement trajectory of the support frame is limited by the sliding of the extension shaft inside the hollow cylinder.

[0026] S413: Place the S32750 alloy plate between the drive shafts, and drive the two drive shafts to rotate by the operation of two sets of drive motors in opposite directions, thereby adjusting the position of the S32750 alloy plate by clamping drive.

[0027] S414: When the S32750 alloy plate passes through the inside of the support frame, the oil tank supplies the flame heater through the hose, the distributor pipe and the feed pipe, and the flame heater preheats the part of the S32750 alloy plate that it passes through.

[0028] As a further aspect of the present invention, the steps of the shaping and cutting stage are specifically as follows:

[0029] S421: When the second electric telescopic rod drives the second tilting frame to adjust the angle in step S411, the second tilting frame applies force to the adjusting shaft, so that the sliding frame adjusts the height along the second angle frame, thereby adjusting the tool holder to the specified height.

[0030] S422: The S32750 alloy plate passes through the shaping roller as the drive motor continues to operate;

[0031] S423: By operating two sets of forming motors in opposite directions, the forming rollers are driven to rotate, further driving the S32750 alloy plate. During the process, the S32750 alloy plate is shaped based on the multi-segment angled cylindrical structure of the forming rollers, thereby providing structural support for the forming process of reinforced pipes.

[0032] S424: After the S32750 alloy plate of a specified length is shaped, the hot cutting blade is driven by the operation of the hydraulic rod to cut the S32750 alloy plate and obtain the pre-treated plate.

[0033] As a further aspect of the present invention, in step S6, the steps of the assembly molding stage specifically include:

[0034] S610: The heat-insulating pipe fitting is placed inside the reinforced pipe fitting and fixed with metal adhesive;

[0035] S620: The heat-insulating pipe fitting is placed inside the corresponding size outer pipe fitting and fixed by metal adhesive and welding to form a seamless pipe main body basic structure;

[0036] S630: Docking grooves are opened at corresponding positions at both ends of the seamless tube body to provide a prerequisite for seamless docking.

[0037] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0038] In this invention, by creating a butt joint groove, calibration points and fulcrums are provided for the seamless welding between the seamless pipe bodies, improving welding accuracy. Furthermore, the internal heat-insulating pipe components provide insulation against the high temperatures that may arise during oil and gas transportation. These components are made of polypropylene and polybutene as base materials, with reinforcing fibers and plasticizers ensuring their strength and toughness. The addition of paraffin wax and modified calcium carbonate ensures their heat insulation performance. A combination of defoamers and air-entraining agents further eliminates large air bubbles and uniformly introduces small molecule air bubbles, enhancing the heat insulation performance and strength of the components. The multi-section angled design of the reinforcing pipe components provides further support to the outer pipe components and provides pressure-bearing space, ensuring overall sealing and strength. In terms of processing, a phased processing method involving pretreatment and shaping / cutting stages, combined with a sheet metal processing device, reduces processing difficulty. Attached Figure Description

[0039] Figure 1 This is a flowchart of the main steps of the present invention;

[0040] Figure 2 This is a schematic diagram of the three-dimensional structure of the seamless tube body of the present invention;

[0041] Figure 3This is an exploded view of the main structure of the seamless tube of the present invention;

[0042] Figure 4 This is a detailed flowchart of step 1 of the present invention;

[0043] Figure 5 This is a schematic diagram of the sheet metal processing device of the present invention;

[0044] Figure 6 This is an exploded schematic diagram of the pretreatment mechanism of the present invention;

[0045] Figure 7 This is an exploded view of the processing and shaping mechanism of the present invention;

[0046] Figure 8 This is a flowchart of the preprocessing stage of the present invention;

[0047] Figure 9 This is a flowchart of the shaping and cutting stage of the present invention;

[0048] Figure 10 The flowchart for step 6 of this invention is detailed below.

[0049] In the diagram: 1. Seamless pipe body; 101. Outer pipe fitting; 102. Reinforcing pipe fitting; 103. Insulated pipe fitting;

[0050] 2. Pre-treatment mechanism; 201. Base plate; 202. Front processing table; 203. No. 1 angle bending frame; 204. No. 1 tilting frame; 205. No. 1 electric telescopic rod; 206. Outer ring; 207. Drive motor; 208. Drive shaft; 209. Oil tank; 210. Hoses; 211. Diverter pipe; 212. Feed pipe; 213. Support frame; 214. Flame heater; 215. Linkage shaft; 216. Extension shaft; 217. Hollow cylinder;

[0051] 3. Processing and shaping mechanism; 301. Post-processing table; 302. No. 2 angle bending frame; 303. No. 2 flipping frame; 304. No. 2 electric telescopic rod; 305. Limiting ring; 306. Shaping motor; 307. Shaping roller; 308. Adjusting shaft; 309. Sliding frame; 310. Tool holder; 311. Hydraulic rod; 312. Hot cutting knife. Detailed Implementation

[0052] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0053] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] Example 1

[0055] Please see Figures 2 to 3 A seamless austenitic-ferritic super duplex stainless steel tube includes a seamless tube body 1, which is composed of an outer tube 101, a reinforcing tube 102, and a heat insulation tube 103. The reinforcing tube 102 is located between the outer tube 101 and the heat insulation tube 103. The reinforcing tube 102 is fixedly connected to the outer tube 101 and the heat insulation tube 103. The reinforcing tube 102 is multi-segmented angled. Both ends of the seamless tube body 1 are provided with butt grooves, and the seamless tube bodies 1 are engaged with each other through the butt grooves.

[0056] Please see Figures 2 to 3 The outer pipe fitting 101 and the reinforcing pipe fitting 102 are both made of S32750 alloy. The heat insulation pipe fitting 103 is made of polypropylene, polybutene, paraffin wax, modified calcium carbonate, and reinforcing fiber. The reaction material of the heat insulation pipe fitting 103 is made of plasticizer, stabilizer, antibacterial agent, defoamer, and air-entraining agent. Each material is composed of the following raw materials in parts by weight: 70-85 parts of polypropylene, 530-35 parts of polybutene, 2-5 parts of paraffin wax, 6-12 parts of modified calcium carbonate, 15-22 parts of reinforcing fiber, 2-3 parts of plasticizer, 3-5 parts of stabilizer, 2-3 parts of antibacterial agent, 5-10 parts of defoamer, and 3-5 parts of air-entraining agent.

[0057] Example 2

[0058] Please see Figure 1 A process for preparing austenitic-ferritic super duplex stainless steel seamless tube includes the following steps:

[0059] S1: Material mixing and processing stage for thermal insulation pipe fitting 103;

[0060] S2: Place the pre-treated material of the heat insulation pipe fitting 103 inside the container;

[0061] S3: The pre-treatment material of the heat insulation pipe fitting 103 is introduced into the tubular mold and cooled to form the heat insulation pipe fitting 103.

[0062] S4: Preparation stage of reinforced pipe fitting 102;

[0063] S5: Weld the two ends of the pre-treated plate to form a tubular structure and obtain the reinforced pipe 102.

[0064] S6: Assembly and forming stage.

[0065] Please see Figure 4 In S1, the specific steps of the material mixing and treatment stage for the thermal insulation pipe fitting 103 are as follows:

[0066] S110: Add the material for preparing the heat insulation pipe 103 into the reaction furnace;

[0067] S120: Plasticizers and stabilizers are added into the prepared material in sequence;

[0068] S130: The material is heated in a reactor to bring it to a molten state, and then stirred and mixed.

[0069] S140: Maintain the temperature inside the reactor at 80℃ and continue stirring and mixing. Introduce the antibacterial agent and defoamer into the reactor and wait for 20 minutes.

[0070] S150: Stop stirring and wait for 30 minutes. At this time, the large air bubbles inside the material are fully discharged by the defoamer to obtain the pre-treated material of the heat insulation pipe fitting 103.

[0071] In S130, the temperature of the reactor heating treatment is 75℃-90℃, the reactor heating treatment method is step heating, the reactor heating treatment time is 25-30min, the stirring and mixing speed is 1200r / min, and the stirring and mixing time is 15min.

[0072] Please see Figure 1 In step S2, the step of placing the pre-treated material of the heat insulation pipe fitting 103 inside the container is as follows: the pre-treated material of the heat insulation pipe fitting 103 obtained in step S150 is introduced into the container and the temperature inside the container is maintained at 45°C. An air-entraining agent is added and stirred evenly. The reaction is waited for 15 minutes. At this time, small molecule bubbles are evenly introduced into the pre-treated material of the heat insulation pipe fitting 103.

[0073] Please see Figures 5 to 6In S3, the preparation stage of the reinforced pipe fitting 102 uses a sheet metal processing device, which consists of a pretreatment mechanism 2 and a processing and shaping mechanism 3. The pretreatment mechanism 2 includes a base plate 201, with a front processing table 202 mounted on the front end of the base plate 201. A first-order bending frame 203 is mounted on both sides of the upper surface of the front processing table 202. A first-order turning frame 204 is rotatably connected to the top of the first-order bending frame 203. A first-order electric telescopic rod 205 is rotatably connected between the first-order turning frame 204 and the first-order bending frame 203. Outer rings 206 are mounted on both the upper and lower surfaces of the first-order turning frame 204. A drive shaft 208 is rotatably connected between the outer rings 206. A drive motor 207 is mounted on the side surface of the outer rings 206. The output end of the motor 207 is fixedly connected to the drive shaft 208. An oil tank 209 is installed at the center of the upper surface of the base plate 201. A hose 210 is installed at the output end of the oil tank 209. A diverter pipe 211 is installed at one end of the hose 210. A feed pipe 212 is installed at both ends of the diverter pipe 211. A support frame 213 is installed on the outer surface of the feed pipe 212. Flame heaters 214 are installed at equal intervals on the outer surface of the feed pipe 212. A linkage shaft 215 is rotatably connected between the support frame 213 and the first tilting frame 204. An extension shaft 216 is installed at each of the four corners of the lower surface of the support frame 213. A hollow cylinder 217 is sleeved on the outer surface of the extension shaft 216. The hollow cylinder 217 is fixedly connected to the base plate 201.

[0074] Please see Figure 7 The processing and shaping mechanism 3 includes a post-processing table 301. Two angle-folding frames 302 are mounted on both sides of the upper surface of the post-processing table 301. A second-order flipping frame 303 is rotatably connected to the top of each angle-folding frame 302. A second-order electric telescopic rod 304 is rotatably connected between the second-order flipping frame 303 and the second-order angle-folding frame 302. Limiting rings 305 are mounted on both the upper and lower surfaces of the second-order flipping frame 303. A shaping roller 307 is rotatably connected between the limiting rings 305. The shaping roller 307 is configured as a multi-segment angled cylinder. The side surfaces of the limiting rings 305... A shaping motor 306 is mounted on the surface. The output end of the shaping motor 306 is fixedly connected to the shaping roller 307. An adjusting shaft 308 is rotatably connected to the rear end of the second flipping frame 303. A sliding frame 309 is rotatably connected to one end of the adjusting shaft 308. The sliding frame 309 is slidably connected to the rear end of the second angle bending frame 302. A knife holder 310 is mounted between the sliding frames 309. Hydraulic rods 311 are mounted on the side surfaces of the two sets of sliding frames 309. A hot cutting knife 312 is mounted on the output end of the hydraulic rod 311. The hot cutting knife 312 is located above the knife holder 310.

[0075] Please see Figure 8 In S4, the preparation stage of reinforced pipe fitting 102 includes a pretreatment stage and a shaping and cutting stage. The specific steps of the pretreatment stage are as follows:

[0076] S411: By operating the No. 1 electric telescopic rod 205 and the No. 2 electric telescopic rod 304, the angles of the No. 1 angle-folding frame 203 and the No. 2 tilting frame 303 are adjusted in opposite directions, thereby limiting the input and output trajectory of the S32750 alloy plate.

[0077] S412: During the angle adjustment process of the first electric telescopic rod 205 driving the first angle bracket 203, the height of the support frame 213 is adjusted through the linkage shaft 215, and the movement trajectory of the support frame 213 is limited by the sliding of the extension shaft 216 inside the hollow cylinder 217.

[0078] S413: Place the S32750 alloy plate between the drive shafts 208. The two sets of drive motors 207 operate in opposite directions, driving the two sets of drive shafts 208 to rotate, thereby adjusting the position of the S32750 alloy plate by clamping drive.

[0079] S414: When the S32750 alloy plate passes through the inside of the support frame 213, the oil tank 209 supplies material to the flame heater 214 through the hose 210, the diversion pipe 211 and the feed pipe 212, and preheats the part of the S32750 alloy plate that has passed through the flame heater 214.

[0080] Please see Figure 9 The specific steps in the shaping and cutting stage are as follows:

[0081] S421: When the second electric telescopic rod 304 drives the second tilting frame 303 to adjust the angle in step S411, the second tilting frame 303 applies force to the adjusting shaft 308, so that the sliding frame 309 adjusts the height along the second angle frame 302, thereby adjusting the tool holder 310 to the specified height.

[0082] S422: The S32750 alloy plate passes through the shaping roller 307 as the drive motor 207 operates further.

[0083] S423: By operating in the opposite direction of two sets of shaping motors 306, the shaping roller 307 is driven to rotate, further driving the S32750 alloy plate. During the process, based on the multi-segment angled cylindrical structure of the shaping roller 307, the S32750 alloy plate is shaped, thereby providing structural support for the shaping process of the reinforcing tube 102.

[0084] S424: After the S32750 alloy plate of a specified length is shaped, the hot cutting blade 312 is driven by the operation of the hydraulic rod 311 to cut the S32750 alloy plate and obtain the pre-treated plate.

[0085] Please see Figure 10 In S6, the specific steps of the assembly and molding stage are as follows:

[0086] S610: Insert the heat insulation fitting 103 into the reinforcing fitting 102 and fix it with metal adhesive;

[0087] S620: The heat insulation pipe fitting 103 is placed inside the corresponding size outer pipe fitting 101 and fixed by metal adhesive and welding to form the basic structure of the seamless pipe body 1.

[0088] S630: Docking grooves are opened at corresponding positions at both ends of the seamless tube body 1 to provide a prerequisite for seamless docking.

[0089] Working principle: The material mixing stage of the heat insulation pipe fitting 103 (the preparation material of the heat insulation pipe fitting 103 is added to the reactor, and plasticizer and stabilizer are added sequentially into the preparation material. The reactor is heated to dissolve the material, and stirring is performed. The temperature inside the reactor is maintained at 80℃, and stirring is continued. Antibacterial agent and defoamer are introduced. After 20 minutes, stirring is stopped, and after 30 minutes, large air bubbles inside the material are fully expelled by the defoamer, resulting in the pre-treated material of the heat insulation pipe fitting 103); the pre-treated material of the heat insulation pipe fitting 103 is introduced into a container, and the temperature inside the container is maintained at 45℃. An air-entraining agent is added and stirred evenly. The reaction is allowed to proceed for 15 minutes. Small molecule bubbles are uniformly introduced into the pre-treatment material of the heat insulation pipe fitting 103; the pre-treatment material of the heat insulation pipe fitting 103 is introduced into the tubular mold and cooled to form the heat insulation pipe fitting 103; in the preparation stage of the reinforced pipe fitting 102, a plate processing device is used, including a pre-treatment stage (by operating the first electric telescopic rod 205 and the second electric telescopic rod 304, the angles of the first angle bending frame 203 and the second flipping frame 303 are adjusted in opposite directions, thereby limiting the input and output trajectory of the S32750 alloy plate; during the angle adjustment process of the first electric telescopic rod 205 driving the first angle bending frame 203, the height of the support frame 213 is adjusted through the linkage shaft 215, and the sliding of the extension shaft 216 inside the hollow cylinder 217 achieves the adjustment of the support frame). The movement trajectory limitation function of 213 places the S32750 alloy sheet between the drive shafts 208. Two sets of drive motors 207 operate in opposite directions, driving the two sets of drive shafts 208 to rotate. The position of the S32750 alloy sheet is adjusted by clamping and driving. When the S32750 alloy sheet passes the inner side of the support frame 213, the oil tank 209 supplies material to the flame heater 214 through the hose 210, the diverter pipe 211, and the supply pipe 212. The flame heater 214 preheats the portion of the S32750 alloy sheet it passes through. In the shaping and cutting stage (when the second electric telescopic rod 304 drives the second tilting frame 303 to adjust the angle in step S411, the second tilting frame 303 applies force to the adjusting shaft 308). This allows the sliding frame 309 to be height-adjusted along the second angle frame 302, thereby adjusting the cutter holder 310 to the specified height. As the drive motor 207 further operates, the S32750 alloy plate passes through the shaping roller 307. Through the relative operation of the two sets of shaping motors 306, the shaping roller 307 is driven to rotate, further driving the S32750 alloy plate. During the process, based on the multi-segment angled cylindrical structure of the shaping roller 307, the S32750 alloy plate is shaped, thereby providing structural support for the shaping process of the reinforcing pipe 102. After the S32750 alloy plate of the specified length is shaped, the hydraulic rod 311 drives the hot cutting blade 312 to press down and cut the S32750 alloy plate to obtain the pre-treated plate.The pre-treated sheet metal is welded at both ends to form a tubular structure, resulting in reinforced pipe 102; in the assembly stage (insulating pipe 103 is placed inside reinforced pipe 102 and fixed with metal adhesive, insulating pipe 103 is placed inside outer pipe 101 of corresponding size and fixed with metal adhesive and welding to form the basic structure of seamless pipe body 1, and butt grooves are opened at corresponding positions at both ends of seamless pipe body 1 to provide preconditions for seamless butt joint).

[0090] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A manufacturing process for a seamless austenitic-ferritic super duplex stainless steel tube, wherein the seamless austenitic-ferritic super duplex stainless steel tube comprises a seamless tube body (1), characterized in that, The seamless tube body (1) is composed of an outer tube (101), a reinforcing tube (102), and a heat insulation tube (103). The reinforcing tube (102) is located between the outer tube (101) and the heat insulation tube (103). The reinforcing tube (102) is fixedly connected to the outer tube (101) and the heat insulation tube (103). The reinforcing tube (102) is multi-segmented angled. Both ends of the seamless tube body (1) are provided with mating grooves. The seamless tube bodies (1) are engaged with each other through the mating grooves. The preparation process Includes the following steps: S1: Material mixing and processing stage for thermal insulation pipe fittings (103); S2: Place the pre-treatment material of the heat insulation pipe fitting (103) inside the container; S3: The pre-treatment material of the heat insulation pipe fitting (103) is introduced into the tubular mold and cooled to form the heat insulation pipe fitting (103). S4: Preparation stage of reinforced pipe fitting (102); S5: Weld the two sides of the pre-treated plate to form a tubular structure and obtain the reinforced pipe (102). S6: Assembly and forming stage; In S4, the preparation stage of the reinforced pipe fitting (102) adopts a plate processing device. The plate processing device consists of a pretreatment mechanism (2) and a processing and shaping mechanism (3). The pretreatment mechanism (2) includes a base plate (201). The front end of the base plate (201) is equipped with a front processing table (202). Both sides of the upper surface of the front processing table (202) are equipped with a first-order angle bending frame (203). The top of the first-order angle bending frame (203) is rotatably connected to a first-order flipping frame (204). A first-order electric telescopic rod (205) is rotatably connected between the first-order flipping frame (204) and the first-order angle bending frame (203). The outer top and bottom surfaces of the first-order flipping frame (204) are equipped with outer rings (206). A drive shaft (208) is rotatably connected between the outer rings (206). A drive motor (207) is installed on the side surface of the outer rings (206). The output end of the machine (207) is fixedly connected to the drive shaft (208). An oil tank (209) is installed at the center of the upper surface of the base plate (201). A hose (210) is installed at the output end of the oil tank (209). A diverter pipe (211) is installed at one end of the hose (210). A feed pipe (212) is installed at both ends of the diverter pipe (211). A support frame (213) is installed on the outer surface of the feed pipe (212). Flame heaters (214) are installed at equal intervals on the outer surface of the feed pipe (212). A linkage shaft (215) is rotatably connected between the support frame (213) and the first flipping frame (204). An extension shaft (216) is installed at each of the four corners of the lower surface of the support frame (213). A hollow cylinder (217) is sleeved on the outer surface of the extension shaft (216). The hollow cylinder (217) is fixedly connected to the base plate (201).

2. The preparation process of austenitic-ferritic super duplex stainless steel seamless tube according to claim 1, characterized in that, The outer pipe fitting (101) and the reinforcing pipe fitting (102) are both made of S32750 alloy. The heat insulation pipe fitting (103) is made of polypropylene, polybutene, paraffin wax, modified calcium carbonate and reinforcing fiber. The reaction material of the heat insulation pipe fitting (103) is made of plasticizer, stabilizer, antibacterial agent, defoamer and air-entraining agent. Each material is composed of the following raw materials in parts by weight: 70-85 parts of polypropylene, 530-35 parts of polybutene, 2-5 parts of paraffin wax, 6-12 parts of modified calcium carbonate, 15-22 parts of reinforcing fiber, 2-3 parts of plasticizer, 3-5 parts of stabilizer, 2-3 parts of antibacterial agent, 5-10 parts of defoamer and 3-5 parts of air-entraining agent.

3. The preparation process of austenitic-ferritic super duplex stainless steel seamless tube according to claim 1, characterized in that, In step S1, the specific steps of the material mixing process for the heat insulation pipe fitting (103) are as follows: S110: Add the material for preparing the heat insulation pipe (103) into the reaction furnace; S120: Plasticizers and stabilizers are added into the prepared material in sequence; S130: The material is heated in a reactor to bring it to a molten state, and then stirred and mixed. S140: Maintain the temperature inside the reactor at 80℃ and continue stirring and mixing. Introduce the antibacterial agent and defoamer into the reactor and wait for 20 minutes. S150: Stop stirring and wait for 30 minutes. At this time, the large air bubbles inside the material are fully discharged by the defoamer to obtain the pre-treated material of the heat insulation pipe fitting (103). In S130, the temperature of the reactor heating treatment is 75℃-90℃, the reactor heating treatment method is step heating, the reactor heating treatment time is 25-30min, the stirring and mixing speed is 1200r / min, and the stirring and mixing time is 15min.

4. The preparation process of austenitic-ferritic super duplex stainless steel seamless tube according to claim 3, characterized in that, In step S2, the step of placing the pre-treated material of the heat insulation pipe fitting (103) inside the container is specifically as follows: the pre-treated material of the heat insulation pipe fitting (103) obtained in step S150 is introduced into the container and the temperature inside the container is maintained at 45°C. An air-entraining agent is added and stirred evenly. The reaction is waited for 15 minutes. At this time, small molecule bubbles are evenly introduced into the pre-treated material of the heat insulation pipe fitting (103).

5. The preparation process of austenitic-ferritic super duplex stainless steel seamless tube according to claim 1, characterized in that, The processing and shaping mechanism (3) includes a post-processing table (301). Two angle-folding frames (302) are mounted on both sides of the upper surface of the post-processing table (301). A second-order flipping frame (303) is rotatably connected to the top of each angle-folding frame (302). A second-order electric telescopic rod (304) is rotatably connected between the second-order flipping frame (303) and the second angle-folding frame (302). Limiting rings (305) are mounted on both the upper and lower surfaces of the second-order flipping frame (303). A shaping roller (307) is rotatably connected between the limiting rings (305). The shaping roller (307) is configured as a multi-segment angled cylinder. The side surface of the limiting rings (305) is equipped with… A shaping motor (306) is fixedly connected to a shaping roller (307) at its output end. An adjusting shaft (308) is rotatably connected to the rear end of the second flipping frame (303). A sliding frame (309) is rotatably connected to one end of the adjusting shaft (308). The sliding frame (309) is slidably connected to the rear end of the second angle bending frame (302). A knife holder (310) is installed between the sliding frames (309). A hydraulic rod (311) is installed on the side surface of the two sets of sliding frames (309). A hot cutting knife (312) is installed at the output end of the hydraulic rod (311). The hot cutting knife (312) is located above the knife holder (310).

6. The preparation process of austenitic-ferritic super duplex stainless steel seamless tube according to claim 1, characterized in that, In step S4, the preparation stage of the reinforced pipe fitting (102) includes a pretreatment stage and a shaping and cutting stage. The specific steps of the pretreatment stage are as follows: S411: By operating the No. 1 electric telescopic rod (205) and the No. 2 electric telescopic rod (304), the angles of the No. 1 angle-folding frame (203) and the No. 2 tilting frame (303) are adjusted in opposite directions, thereby limiting the input and output trajectory of the S32750 alloy plate; S412: During the angle adjustment process of the No. 1 electric telescopic rod (205) driving the No. 1 angle bracket (203), the height of the support frame (213) is adjusted through the linkage shaft (215), and the movement trajectory of the support frame (213) is limited by the sliding of the extension shaft (216) inside the hollow cylinder (217). S413: Place the S32750 alloy plate between the drive shafts (208), and drive the two drive shafts (208) to rotate by the operation of the two drive motors (207) in opposite directions, thereby adjusting the position of the S32750 alloy plate by clamping drive. S414: When the S32750 alloy plate passes through the inside of the support frame (213), the oil tank (209) supplies the flame heater (214) through the hose (210), the diversion pipe (211) and the feed pipe (212), and the S32750 alloy plate is preheated through the flame heater (214).

7. The preparation process of austenitic-ferritic super duplex stainless steel seamless tube according to claim 6, characterized in that, The specific steps of the shaping and cutting stage are as follows: S421: When the second electric telescopic rod (304) drives the second tilting frame (303) to adjust the angle in step S411, the second tilting frame (303) applies force to the adjusting shaft (308), so that the sliding frame (309) adjusts the height along the second angle frame (302), thereby adjusting the tool holder (310) to the specified height; S422: The S32750 alloy plate passes through the shaping roller (307) as the drive motor (207) operates further. S423: By operating in the opposite direction of two sets of shaping motors (306), the shaping roller (307) is driven to rotate, further driving the S32750 alloy plate. In the process, based on the multi-segment angled cylindrical structure of the shaping roller (307), the S32750 alloy plate is shaped, thereby providing structural support for the shaping process of the reinforcing tube (102). S424: After the S32750 alloy plate of a specified length is shaped, the hot cutting knife (312) is driven to press down by the operation of the hydraulic rod (311) to cut the S32750 alloy plate and obtain the pre-treated plate.

8. The preparation process of austenitic-ferritic super duplex stainless steel seamless tube according to claim 1, characterized in that, In step S6, the steps of the assembly and molding stage are specifically as follows: S610: Insert the heat insulation fitting (103) into the reinforcing fitting (102) and fix it with metal adhesive; S620: The heat insulation pipe fitting (103) is placed inside the corresponding size outer pipe fitting (101) and fixed by metal adhesive and welding to form the basic structure of the seamless pipe body (1); S630: A docking groove is opened at the corresponding positions at both ends of the seamless tube body (1) to provide a prerequisite for seamless docking.

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