Production process and production device of aerospace high-pressure-resistant low-temperature-resistant corrosion-resistant austenitic seamless stainless pipe

Abstract

The application discloses a production process and a production device of a high-pressure-resistant, low-temperature-resistant and corrosion-resistant austenitic seamless stainless pipe for aerospace, and the production process comprises the following steps: raw material preparation, cutting, heating treatment, rolling forming, heat treatment, cooling treatment, straightening treatment, surface treatment, quality detection and packaging and warehousing, and the production equipment used in the cooling treatment step comprises a comprehensive billet cooling box, a load driving hydraulic cylinder, a billet air cooling conveyor and a medium cooling conveying claw. The application has four cooling treatments of water quenching, oil quenching, gas quenching and air cooling, the cooling conveying assembly mechanism makes the billet have two conveying routes, can better make the billet synchronously cooled in two cooling modes of liquid medium cooling and gas medium cooling in different modes, prevents the cooling treatment of the latter billet from being affected by the former billet, and improves the free flexibility of the cooling process operation.

Description

Technical Field

[0001] This invention relates to the field of aerospace high-pressure, low-temperature, and corrosion-resistant steel pipe production, specifically a production process and equipment for aerospace high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel pipe. Background Technology

[0002] Austenitic seamless stainless steel tubing used in aerospace is a high-precision, high-performance material primarily used in the manufacture of critical components for high-end equipment such as aero engines and rocket propulsion systems. This tubing possesses excellent corrosion resistance, high-temperature resistance, and high-pressure resistance, maintaining stable performance even in extreme environments.

[0003] High-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel pipe is a special type of pipe with excellent performance, widely used in petroleum, chemical, marine engineering, aerospace, and other fields. The characteristics of this pipe are as follows: High pressure resistance: Due to the use of high-precision, high-strength materials and processes, this pipe can withstand extremely high pressures, ensuring the safety and stability of the pipeline system. Good low-temperature resistance: It can maintain good toughness and strength at extremely low temperatures, preventing the pipe from becoming brittle or breaking. Excellent corrosion resistance: It has excellent corrosion resistance, resisting corrosion from various acids, alkalis, salts, and other chemicals, thus ensuring the long-term stable operation of the pipeline system. Long service life: Due to its excellent corrosion resistance and high-pressure resistance, this pipe has a long service life, reducing replacement and maintenance costs. Easy installation: Its seamless design makes pipe connection and installation relatively simple, reducing construction difficulty and costs.

[0004] In the production process of aerospace-grade high-pressure, low-temperature, and corrosion-resistant steel pipes, cooling is one of the most important steps to maintain the austenitic structure of the steel pipe. There are two main methods for cooling austenitic steel pipes: liquid cooling and gas cooling. Liquid cooling is further divided into water cooling and oil cooling, while gas cooling is divided into air cooling and inert gas cooling (nitrogen, argon, helium, etc.).

[0005] Currently, austenitic steel pipe cooling devices only support a single cooling method, lacking both liquid and gaseous cooling options. This limits the flexibility of steel pipe cooling, resulting in low production process flexibility. Furthermore, existing cooling equipment cannot simultaneously cool multiple steel pipes using different methods, as cooling is constrained by the preceding pipes. Overall, the cooling operation lacks flexibility, and cooling efficiency needs improvement.

[0006] Therefore, it is essential to invent a production process and equipment for aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tubes. Summary of the Invention

[0007] The purpose of this invention is to provide a production process and apparatus for aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel pipes. This addresses the limitations of existing production processes and apparatuses for aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel pipes, which cannot simultaneously employ both liquid and gaseous cooling methods. Furthermore, these methods have limitations, resulting in low flexibility in the steel pipe cooling process. Additionally, they cannot simultaneously cool multiple steel pipes using different methods, and the cooling is constrained by the preceding steel pipe, leading to poor overall flexibility in the cooling production operation.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a manufacturing process for aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tubes, comprising the following steps:

[0009] Step 1: Raw material preparation: Select high-purity, low-impurity raw materials with good stability, such as high-purity nickel, chromium, and iron;

[0010] Step 2: Cutting: Cut the raw materials into appropriate sizes for the next step of heat treatment;

[0011] Step 3: Heat treatment: Heat the cut raw material to the austenitic state. It usually needs to be heated to a high temperature (above 1100℃) and held for a period of time to allow the raw material to completely transform into an austenitic structure.

[0012] Step 4: Rolling and Shaping: The heated raw material is rolled into a tube blank of the required shape and size. This process requires controlling the rolling temperature and pressure to ensure the quality of the tube blank.

[0013] Step 5: Heat treatment: The rolled tube blank is heat treated to further stabilize its microstructure and improve its corrosion resistance;

[0014] Step 6: Cooling treatment: The heat-treated tube blank is rapidly cooled to maintain its austenitic structure. The tube blank is cooled by air cooling, oil quenching, gas quenching, or water quenching.

[0015] Step 7: Straightening treatment: Straighten the cooled tube blank to eliminate its bending and twisting deformation;

[0016] Step 8: Surface treatment: Polishing, pickling, passivation and other treatments are performed on the surface of the pipe to improve its corrosion resistance;

[0017] Step 9: Quality Inspection: Conduct comprehensive quality inspection on the produced austenitic seamless stainless steel tubes, including inspection of dimensions, appearance, microstructure, corrosion resistance, etc.

[0018] Step 10: Packaging and Warehousing: Pack the qualified products and store them in a dry, well-ventilated warehouse, avoiding contact with corrosive substances.

[0019] Furthermore, the equipment used in the cooling process of the production process of aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel pipes is characterized by: including a comprehensive billet cooling box, a load-driven hydraulic cylinder, a billet air-cooling conveyor, and a medium-cooling conveying claw. At least three sets of the load-driven hydraulic cylinders are fixedly installed on the comprehensive billet cooling box, with four load-driven hydraulic cylinders forming a group. The output end of one group of load-driven hydraulic cylinders is fixedly connected to the billet air-cooling conveyor. A medium-cooling conveying claw is fixedly installed below the billet air-cooling conveyor. The billet air-cooling conveyor and the medium-cooling conveying claw together form a cooling conveying assembly. At least three of these cooling conveying assemblies are provided and located directly above the comprehensive billet cooling box, which is located on one side of the heat treatment equipment.

[0020] Furthermore, the integrated billet cooling box includes an integrated cooling box, a medium cooling pool, conveying rollers, liquid medium inlets, a gas medium ejection pipe assembly, a liquid upflow pipe, a cooling medium conveying pipe, a gas transport pipe, and a high-pressure air pump. Three sets of load-driven hydraulic cylinders are fixedly installed above the integrated cooling box. At least three medium cooling pools are provided on the integrated cooling box. A cooling conveying assembly is provided directly above the medium cooling pools. At least four sets of conveying rollers are rotatably installed on the integrated cooling box, in groups of three. The conveying rollers are located on both sides of the medium cooling pools. One of the medium cooling pools is connected to two liquid medium inlets installed outside the integrated cooling box. The other two medium cooling pools are respectively fixedly installed with a gas medium ejection pipe assembly and a liquid upflow pipe. A cooling medium conveying pipe and a gas transport pipe are fixedly installed outside the integrated cooling box. The cooling medium conveying pipe is connected to the gas medium ejection pipe assembly. The gas transport pipe on one side of the cooling medium conveying pipe is connected to the liquid upflow pipe, and a high-pressure air pump is fixedly installed at one end of the gas transport pipe.

[0021] Furthermore, the billet air-cooled conveyor includes a load frame, a duct fan, a groove, a conveying roller shaft, a torque shaft, a power motor, mounting heads, and a conveying rod shaft. Several duct fans are fixedly installed in the middle of the load frame. A groove is formed on the load frame and located on both sides of the duct fans. Conveying roller shafts are rotatably installed within the groove. The load frame is fixedly connected to the output end of the load-driven hydraulic cylinder. A medium-cooling conveying claw is fixedly installed below the load frame. Torque shafts are rotatably installed on both sides of the load frame. Either end of the torque shaft rotatably passes through the load frame and is fixedly connected to the output end of the power motor fixedly installed externally. There are two torque shafts, and several mounting heads are fixedly installed on each of the two torque shafts. The conveying rod shaft is rotatably installed on each mounting head.

[0022] Furthermore, the medium cooling conveying claw includes a mounting base, a connecting guardrail plate, a load claw plate, a tension spring, limiting rollers, limiting bearing plates, and rolling heads. Two mounting bases are provided, fixedly installed at both ends below the load frame base. The mounting base is rotatably connected to the connecting guardrail plate, which is rotatably connected to the load claw plate. The load claw plate is elastically connected to the mounting base via a tension spring. Several limiting rollers are rotatably mounted on the mounting base, and several limiting bearing plates are fixedly mounted on the mounting base. Rolling heads are rotatably mounted on the limiting bearing plates, and the limiting bearing plates are rotatably mounted on a bearing shaft.

[0023] Furthermore, the integrated cooling box is provided with at least three medium cooling pools, namely a water quenching pool, an oil quenching pool, and a gas quenching pool. The oil quenching pool of the medium cooling pool is not provided with a gas medium ejection pipe group and a liquid surge pipe, but is connected to two liquid medium ports provided on the outside. These two liquid medium ports are an injection port and a discharge port.

[0024] Furthermore, the gas medium ejection pipe assembly has a 'U' shaped structure and is installed below the bottom of the gas quenching tank. Several gas medium ejection pipe assemblies are respectively connected to the cooling medium conveying pipe. The liquid upflow pipe is a fishbone shaped pipe and is connected to two external liquid upflow pipes.

[0025] Furthermore, the load frame base has an "I" shaped structure, and a through hole for installing the exhaust fan is provided in the middle of the load frame base. This through hole allows airflow to pass through, and roller grooves and conveying roller shafts are respectively provided on both sides of the exhaust fan.

[0026] Furthermore, the mounting heads mounted on the two torque shafts are arranged in a staggered manner, and the mounting heads have a cam-type structure. The length of the conveyor shaft that is rotatably mounted on the mounting heads is allowed to form an 'X' cross structure.

[0027] Furthermore, the load claw plate has an 'L' shaped structure, and the load claw plate has a through groove that allows the limiting roller to rotate and be installed. Several limiting bearing plates fixedly installed on the two load claw plates are arranged in a staggered manner. The two sets of limiting bearing plates are rotatably installed on the bearing shaft, and the two sets of limiting bearing plates are arranged in an interlaced 'X' shape.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. The integrated billet cooling box of the present invention can simultaneously meet the cooling requirements of both liquid medium cooling and gas medium cooling, and has four cooling treatments: water quenching, oil quenching, gas quenching and air cooling. Furthermore, the integrated billet cooling box is equipped with an auxiliary cooling structure, which can effectively improve the cooling effect and efficiency of the billet directly or indirectly.

[0030] 2. The cooling conveying assembly (blank air-cooled conveyor and medium-cooled conveying claw) of the present invention provides the billet with two conveying routes. This arrangement allows the billet to be cooled simultaneously by liquid medium or gas medium, preventing the former from affecting the cooling of the latter and improving the freedom and flexibility of the cooling process operation.

[0031] 3. The billet air-cooling conveyor of the present invention has two working modes: air-cooling conveying mode and normal conveying mode. These two billet conveying modes can further improve the freedom and flexibility of the cooling process operation, making it easy to separate the air cooling and normal conveying steps, avoiding mutual interference between the cooling and conveying steps. In addition, the billet air-cooling conveyor can also extract the air below, which can effectively treat the steam or waste gas generated by oil quenching, air quenching, and water quenching, avoid gas stagnation, avoid obstructing the operator's view, improve the efficiency of subsequent air cooling, and facilitate the discharge of heat from subsequent cooling processes, reducing heat accumulation.

[0032] 4. The medium cooling conveying claw of the present invention is mainly used to realize oil quenching, air quenching, and water quenching of steel billets. Secondly, it also has the function of conveying steel billets. The medium cooling conveying claw has a compact and compact structural design, strong overall load capacity, and the cooling medium can easily flow around it, reducing the impact of the medium cooling conveying claw on the cooling process of the steel billet itself. In addition, the medium cooling conveying claw does not require too many driving components to realize the normal gripping and release of steel billets. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0034] Figure 2This is a schematic diagram of the integrated steel billet cooling box structure of the present invention.

[0035] Figure 3 This is another structural schematic diagram of the integrated steel billet cooling box of the present invention.

[0036] Figure 4 This is a schematic diagram of the cooling conveying assembly structure of the present invention.

[0037] Figure 5 This is another structural schematic diagram of the cooling conveying assembly mechanism of the present invention.

[0038] Figure 6 This is a schematic diagram of the billet air-cooled conveyor structure of the present invention.

[0039] Figure 7 This is another structural schematic diagram of the billet air-cooled conveyor of the present invention.

[0040] Figure 8 This is a schematic diagram of the medium cooling conveying claw structure of the present invention.

[0041] Figure 9 This is another structural schematic diagram of the medium cooling conveying claw of the present invention.

[0042] In the picture:

[0043] The system includes: 1. Integrated billet cooling box; 11. Integrated cooling box; 12. Medium cooling pool; 13. Conveying roller; 14. Liquid medium inlet; 15. Gas medium spray pipe assembly; 16. Liquid upflow pipe; 17. Cooling medium conveying pipe; 18. Gas transport pipe; 19. High-pressure air pump; 2. Load-driven hydraulic cylinder; 3. Billet air-cooled conveyor; 31. Load frame base; 32. Drainage fan; 33. Groove; 34. Conveying roller shaft; 35. Torque shaft; 36. Power motor; 37. Mounting head; 38. Conveying rod shaft; 4. Medium cooling conveying claw; 41. Mounting base; 42. Connecting guardrail plate; 43. Load claw plate; 44. Tension spring; 45. Limiting roller; 46. Limiting bearing plate; 47. Rolling head. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] As attached Figure 1-6 As shown:

[0046] A manufacturing process for aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tubes includes the following steps:

[0047] Step 1: Raw material preparation: Select high-purity, low-impurity raw materials with good stability, such as high-purity nickel, chromium, and iron;

[0048] Step 2: Cutting: Cut the raw materials into appropriate sizes for the next step of heat treatment;

[0049] Step 3: Heat treatment: Heat the cut raw material to the austenitic state, usually requiring heating to a high temperature of over 1100℃ and holding it for a period of time to completely transform the raw material into an austenitic structure.

[0050] Step 4: Rolling and Shaping: The heated raw material is rolled into a tube blank of the required shape and size. This process requires controlling the rolling temperature and pressure to ensure the quality of the tube blank.

[0051] Step 5: Heat treatment: The rolled tube blank is heat treated to further stabilize its microstructure and improve its corrosion resistance;

[0052] Step 6: Cooling treatment: The heat-treated tube blank is rapidly cooled to maintain its austenitic structure. The tube blank is cooled by air cooling, oil quenching, gas quenching, or water quenching.

[0053] Step 7: Straightening treatment: Straighten the cooled tube blank to eliminate its bending and twisting deformation;

[0054] Step 8: Surface treatment: Polishing, pickling, passivation and other treatments are performed on the surface of the pipe to improve its corrosion resistance;

[0055] Step 9: Quality Inspection: Conduct comprehensive quality inspection on the produced austenitic seamless stainless steel tubes, including inspection of dimensions, appearance, microstructure, corrosion resistance, etc.

[0056] Step 10: Packaging and Warehousing: Pack the qualified products and store them in a dry, well-ventilated warehouse, avoiding contact with corrosive substances.

[0057] The production equipment used in the cooling process of aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube manufacturing process includes a comprehensive billet cooling box 1, load-driven hydraulic cylinders 2, a billet air-cooling conveyor 3, and a medium-cooling conveying claw 4. At least three sets of the aforementioned load-driven hydraulic cylinders 2 are fixedly installed on the comprehensive billet cooling box 1, with four load-driven hydraulic cylinders 2 forming a group. The output end of one group of load-driven hydraulic cylinders 2 is fixedly connected to the billet air-cooling conveyor 3. A medium-cooling conveying claw 4 is fixedly installed below the billet air-cooling conveyor 3. The billet air-cooling conveyor 3 and... The medium cooling conveying claws 4 are assembled together to form a cooling conveying assembly. There are at least three of these cooling conveying assemblies, which are located directly above the integrated billet cooling box 1. The integrated billet cooling box 1 is located on one side of the heat treatment equipment and serves as the cooling treatment mechanism for the billet. The billet air-cooling conveyor 3 and the medium cooling conveying claws 4 are the billet conveying and gripping mechanisms. When the medium cooling conveying claws 4 descend to the required cooling position, the billet air-cooling conveyor 3 will form a second conveying route and will be flush with the conveying structure of the integrated billet cooling box 1.

[0058] Specifically, the integrated billet cooling box 1 includes an integrated cooling box 11, a medium cooling pool 12, a conveying roller 13, a liquid medium inlet 14, a gas medium ejection pipe assembly 15, a liquid upflow pipe 16, a cooling medium conveying pipe 17, a gas transport pipe 18, and a high-pressure air pump 19. Three sets of load-driven hydraulic cylinders 2 are fixedly installed above the integrated cooling box 11. At least three medium cooling pools 12 are provided on the integrated cooling box 11. A cooling conveying assembly is located directly above the medium cooling pools 12. At least four sets of conveying rollers 13 are rotatably installed, in groups of three. The conveying rollers 13 are located on both sides of the medium cooling pool 12. One of the medium cooling pools 12 is connected to two liquid medium inlets 14 installed on the outside of its integrated cooling box 11. The other two medium cooling pools 12 are respectively fixedly installed with gas medium ejection pipe groups 15 and liquid surge pipes 16. The integrated cooling box 11 is fixedly installed with a cooling medium conveying pipe 17 and a gas transport pipe 18. The cooling medium conveying pipe 17 is connected to the gas medium... The gas jet assembly 15 is connected to the cooling medium delivery pipeline 17. The gas transport pipeline 18 on one side of the cooling medium delivery pipeline 17 is connected to the liquid upflow pipeline 16. A high-pressure air pump 19 is fixedly installed at one end of the gas transport pipeline 18. Two of the three medium cooling pools 12 in the integrated cooling box 11 are filled with liquids required for oil quenching and liquids required for water quenching. These two medium cooling pools 12 containing liquids are liquid cooling areas. When the steel billet enters the water quenching medium cooling pool 12, the high-pressure air pump 19 is turned on. The high-pressure air pump 19 injects high-pressure gas into the liquid upflow pipeline 16. The high-pressure gas enters the liquid upflow pipeline 16 and is discharged outside through the liquid upflow pipeline 16. After the high-pressure gas enters the liquid, the gas diffuses and dissolves into the liquid. The pressure of the gas is greater than the pressure of the liquid. The dissolved gas is released under the action of pressure, forming bubbles. As the bubbles rise and expand, they will generate a pushing force on the surrounding liquid, causing the liquid to rise. The rising liquid continuously contacts and impacts the high-temperature steel billet, which improves the cooling effect of the steel billet to a certain extent.

[0059] Specifically, the billet air-cooled conveyor 3 includes a load frame 31, a induced draft fan 32, a groove 33, a conveyor roller shaft 34, a torque shaft 35, a power motor 36, a mounting head 37, and a conveyor rod shaft 38. Several induced draft fans 32 are fixedly installed in the middle of the load frame 31. Grooves 33 are formed on the load frame 31 and located on both sides of the induced draft fans 32. Conveyor roller shafts 34 are rotatably installed within the grooves 33. The load frame 31 is fixedly connected to the output end of the load-driven hydraulic cylinder 2. A medium-cooled conveying claw 4 is fixedly installed below the load frame 31. Torque shafts 35 are rotatably installed on both sides of the load frame 31. Either end of the torque shaft 35 rotatably passes through the load frame 31 and is fixedly connected to the power motor 36. The output end is fixedly connected. There are two torque shafts 35. Several mounting heads 37 are fixedly installed on the two torque shafts 35 respectively. The conveying rod shaft 38 is rotatably installed on the mounting head 37. When the medium cooling pool 12 below the billet air-cooled conveyor 3 performs oil quenching, water quenching, or air quenching on the billet, it turns on its own induced draft fan 32. The suction force generated by the induced draft fan 32 draws in the gas, steam, or waste gas generated during cooling below and discharges it to the top. In addition, it should be noted that a gas treatment pipe can be added to the billet air-cooled conveyor 3. This pipe is a telescopic pipe and is connected to the gas treatment equipment. The gas, steam, or waste gas generated during cooling is discharged into the gas treatment equipment through the gas treatment pipe for purification treatment.

[0060] Specifically, the medium cooling conveying claw 4 includes a mounting base 41, a connecting guardrail plate 42, a load claw plate 43, a tension spring 44, a limiting roller 45, a limiting bearing plate 46, and a rolling head 47. Two mounting bases 41 are provided, fixedly installed at both ends below the load frame base 31. The mounting base 41 is rotatably connected to the connecting guardrail plate 42, and the connecting guardrail plate 42 is rotatably connected to the load claw plate 43. The load claw plate 43 is elastically connected to the mounting base 41 via the tension spring 44. Several limiting rollers 45 are rotatably mounted on the mounting base 41. Several limiting bearing plates 46 are fixedly mounted on the mounting base 41, and rolling heads 47 are rotatably mounted on the limiting bearing plates 46. The limiting bearing plates 46 are rotatably mounted on a bearing shaft. The load claw plate 43 has a built-in drive motor, the output end of which is fixedly connected to any end of at least one of the limiting rollers 45. The limiting roller 45 connected to it is used to convey the cooled steel billet forward.

[0061] Specifically, the integrated cooling box 11 is equipped with at least three medium cooling pools 12, namely a water quenching pool, an oil quenching pool, and a gas quenching pool. The oil quenching pool of the medium cooling pool 12 is not equipped with a gas medium ejection pipe assembly 15 and a liquid surge pipe 16, but is connected to two liquid medium ports 14 on the outside. These two liquid medium ports 14 are an injection port and a discharge port. The water quenching pool is also equipped with an injection port and a discharge port on the outside, and is connected to them. The gas quenching pool is equipped with a gas medium ejection pipe assembly 15. The cooling medium conveying pipe 17 connected to the gas medium ejection pipe assembly 15 is connected to the gas quenching medium generator. The inert cooling medium for gas quenching is injected into it through the cooling medium conveying pipe 17 and the gas medium ejection pipe assembly 15.

[0062] Specifically, the gas medium ejection pipe assembly 15 has a 'U' shaped structure and is installed below the bottom of the gas quenching tank. Several of the gas medium ejection pipe assemblies 15 are connected to the cooling medium conveying pipe 17. The liquid upflow pipe 16 is a fishbone shaped pipe and is connected to two external liquid upflow pipes 16. Both the gas medium ejection pipe assembly 15 and the liquid upflow pipe 16 are provided with discharge nozzles, which are used to discharge inert gas and high-pressure gas. When the billet needs to be gas quenched, the billet will be located inside the gas medium ejection pipe assembly 15.

[0063] Specifically, the load frame base 31 has an "I" shaped structure. A through hole for installing the airflow fan 32 is opened in the middle of the load frame base 31, which allows airflow to pass through. Roller grooves 33 and conveying roller shafts 34 are respectively provided on both sides of the airflow fan 32. At least one of the conveying roller shafts 34 is fixedly connected to the motor output end built into the load frame base 31. The conveying roller shaft 34 connected to the built-in motor is the conveying roller part. The power motor 36 drives the conveying rod shaft 38 through the torque shaft 35 and the mounting head 37. The two sets of conveying rod shafts 38 can form an "eight" shape and an "X" shape. The two sets of conveying rod shafts 38 forming an "eight" shape is the billet conveying mode.

[0064] Specifically, the mounting heads 37 installed on the two torque shafts 35 are arranged in a staggered manner. The mounting head 37 has a cam-type structure and a motor for conveying is built into the mounting head 37. The output end of the motor is fixedly connected to the conveying rod shaft 38. The length of the conveying rod shaft 38 rotatably mounted on the mounting head 37 is allowed to form an 'X' cross structure. When two sets of conveying rod shafts 38 form an 'X' shape, it is the billet air cooling mode.

[0065] Specifically, the load claw plate 43 has an 'L' shaped structure, and a slot is provided on the load claw plate 43 to allow the medium to flow. The slot is determined according to the requirements. The load claw plate 43 also has a through groove to allow the limiting roller 45 to be rotatably installed. Several limiting bearing plates 46 fixedly installed on the two load claw plates 43 are arranged in a staggered manner. The two sets of limiting bearing plates 46 are rotatably installed on the bearing shaft. The two sets of limiting bearing plates 46 are arranged in an interlaced 'X' shape. The two sets of limiting bearing plates 46 are used to constrain each other and improve the overall load capacity.

[0066] When cooling the steel billet, an aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel pipe production device is required: the heat-treated steel billet is transported to the integrated steel billet cooling box 1. The conveying rollers 13 of the integrated steel billet cooling box 1 assist in the transport of the steel billet. During this process, the steel billet can be rotated for cooling. If air cooling is required for the steel billet during gas cooling, the exhaust fan 32 of the steel billet air-cooling conveyor 3 is turned on first, and the power motor 36 is turned on. The power motor 36 drives the torque shaft 35, and the torque shaft 35 drives the conveying rod shaft 38 through the mounting head 37. The two sets of conveying rod shafts 38 form an 'X' shape. When it is necessary to note that the load-driven hydraulic cylinder 2 needs to drive the steel billet air-cooling conveyor 3 to a suitable height. The steel billet is slowly transported on the two sets of conveying roller shafts 34. During this process, the outside air cools the steel billet.

[0067] When gas quenching is required for gas cooling of steel billets, the billets are conveyed to the medium cooling conveyor claw 4 above the gas quenching medium cooling tank 12. The billets first contact the rolling head 47 of the medium cooling conveyor claw 4. Under the weight of the billets, the lower part of the load claw plate 43 expands outward, while the upper part of the load claw plate 43 expands inward, driving the connecting railing plate 42 and the tension spring 44 to stretch. At this time, the limiting roller 45 installed on the load claw plate 43 contacts the billets, and the limiting roller 45 drives the billets to be conveyed. When the billets are conveyed to the appropriate position, the load-driven hydraulic cylinder 2 drives the medium cooling conveyor claw 4 through the billet air-cooling conveyor 3. After the medium cooling conveyor claw 4 enters the gas quenching medium cooling tank 12, the inert gas required for gas quenching is injected into it, thus performing gas quenching treatment. The working method of this gas quenching is the same as that of oil quenching and water quenching. The difference is that the gas injected after water quenching is high-pressure gas, not inert gas, while oil quenching does not require the injection of any gas.

[0068] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A production apparatus for aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tubes, which is used in the cooling process step of the following process: Step 1: Raw material preparation: Select high-purity, low-impurity raw materials with good stability, such as high-purity nickel, chromium, and iron; Step 2: Cutting: Cut the raw materials into appropriate sizes for the next step of heat treatment; Step 3: Heat treatment: Heat the cut raw material to the austenitic state, usually to above 1100℃ and hold for a period of time to completely transform the raw material into an austenitic structure. Step 4: Rolling and forming: The heated raw material is rolled into a tube blank of the required shape and size. During this process, the rolling temperature and pressure need to be controlled to ensure the quality of the tube blank. Step 5: Heat treatment: The rolled tube blank is heat treated to further stabilize its microstructure and improve its corrosion resistance; Step 6: Cooling treatment: The heat-treated tube blank is rapidly cooled to maintain its austenitic structure. The tube blank is cooled by air cooling, oil quenching, gas quenching and water quenching. Step 7: Straightening treatment: Straighten the cooled tube blank to eliminate its bending and twisting deformation; Step 8: Surface treatment: Polish, pickle and passivate the surface of the pipe to improve its corrosion resistance; Step 9: Quality Inspection: Conduct a comprehensive quality inspection on the produced austenitic seamless stainless steel tubes, including inspection of dimensions, appearance, microstructure, and corrosion resistance. Step 10: Packaging and Warehousing: Pack the qualified products and store them in a dry, well-ventilated warehouse, avoiding contact with corrosive substances; The invention is characterized by comprising a comprehensive billet cooling box (1), a load-driven hydraulic cylinder (2), a billet air-cooling conveyor (3), and a medium-cooling conveying claw (4). At least three sets of the load-driven hydraulic cylinders (2) are fixedly installed on the comprehensive billet cooling box (1), and four load-driven hydraulic cylinders (2) form a group. The output end of one group of load-driven hydraulic cylinders (2) is fixedly connected to the billet air-cooling conveyor (3). A medium-cooling conveying claw (4) is fixedly installed below the billet air-cooling conveyor (3). The billet air-cooling conveyor (3) and the medium-cooling conveying claw (4) are combined to form a cooling conveying assembly. At least three of the cooling conveying assemblies are provided and located directly above the comprehensive billet cooling box (1). The comprehensive billet cooling box (1) is located on one side of the heat treatment equipment.

2. The aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube production apparatus as described in claim 1, characterized in that: The integrated billet cooling box (1) includes an integrated cooling box (11), a medium cooling pool (12), conveying rollers (13), a liquid medium inlet (14), a gas medium ejection pipe assembly (15), a liquid upflow pipe (16), a cooling medium conveying pipe (17), a gas transport pipe (18), and a high-pressure air pump (19). Three sets of load-driven hydraulic cylinders (2) are fixedly installed above the integrated cooling box (11). At least three medium cooling pools (12) are provided on the integrated cooling box (11). A cooling conveying assembly is provided directly above the medium cooling pools (12). At least four sets of conveying rollers (13) are rotatably installed on the integrated cooling box (11), in groups of three. The conveying rollers (13) are located at the medium cooling pools (14). On both sides of 12), one of the medium cooling pools (12) is connected to two liquid medium ports (14) installed outside the integrated cooling box (11). The other two medium cooling pools (12) are respectively fixedly installed with gas medium ejection pipe group (15) and liquid surge pipe (16). The integrated cooling box (11) is fixedly installed with cooling medium conveying pipe (17) and gas transport pipe (18). Cooling medium conveying pipe (17) is connected to gas medium ejection pipe group (15). The gas transport pipe (18) on one side of cooling medium conveying pipe (17) is connected to liquid surge pipe (16). A high-pressure air pump (19) is fixedly installed on one end of the gas transport pipe (18).

3. The aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube production apparatus as described in claim 1, characterized in that: The billet air-cooled conveyor (3) includes a load frame (31), a induced draft fan (32), a groove (33), a conveyor roller shaft (34), a torque shaft (35), a power motor (36), a mounting head (37), and a conveyor rod shaft (38). Several induced draft fans (32) are fixedly installed in the middle of the load frame (31). The load frame (31) has grooves (33) on both sides of the induced draft fans (32). The conveyor roller shaft (34) is rotatably installed in the grooves (33). The load frame (31) is connected to the load drive hydraulic system. The output end of the cylinder (2) is fixedly connected. A medium cooling conveying claw (4) is fixedly installed below the load frame base (31). Torque shafts (35) are rotatably installed on both sides of the load frame base (31). Any end of the torque shaft (35) rotatably passes through the load frame base (31) and is fixedly connected to the output end of the power motor (36) fixedly installed outside it. There are two torque shafts (35). Several mounting heads (37) are fixedly installed on the two torque shafts (35). The conveying rod shaft (38) is rotatably installed on the mounting head (37).

4. The aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube production apparatus as described in claim 1, characterized in that: The medium cooling conveying claw (4) includes a mounting base (41), a connecting guardrail plate (42), a load claw plate (43), a tension spring (44), a limiting roller (45), a limiting bearing plate (46), and a rolling head (47). There are two mounting bases (41). The mounting bases (41) are fixedly installed at both ends below the load frame base (31). The mounting bases (41) are rotatably connected to the connecting guardrail plate (42). The connecting guardrail plate (42) is rotatably connected to the load claw plate (43). The load claw plate (43) is elastically connected to the mounting bases (41) through the tension spring (44). Several limiting rollers (45) are rotatably installed on the mounting bases (41). Several limiting bearing plates (46) are fixedly installed on the mounting bases (41). A rolling head (47) is rotatably installed on the limiting bearing plates (46). Several limiting bearing plates (46) are rotatably installed on the bearing shaft.

5. The aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube production apparatus as described in claim 2, characterized in that: The integrated cooling box (11) is provided with at least three medium cooling pools (12), namely a water quenching pool, an oil quenching pool and a gas quenching pool. The oil quenching pool of the medium cooling pool (12) is not provided with a gas medium ejection pipe group (15) and a liquid surge pipe (16), but is connected to two liquid medium ports (14) provided on the outside. The two liquid medium ports (14) are an injection port and a discharge port.

6. The aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube production apparatus as described in claim 2, characterized in that: The gas medium ejection pipe assembly (15) has a 'U' shaped structure. The gas medium ejection pipe assembly (15) is installed below the bottom of the gas quenching tank. Several gas medium ejection pipe assemblies (15) are connected to the cooling medium conveying pipe (17) respectively. The liquid upflow pipe (16) is a fishbone shaped pipe. The liquid upflow pipe (16) is connected to two external liquid upflow pipes (16).

7. The aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube production apparatus as described in claim 3, characterized in that: The load frame base (31) has an I-shaped structure. The load frame base (31) has a through hole in the middle for installing the air duct fan (32). The through hole allows airflow to pass through. The air duct fan (32) has a roller groove (33) and a conveying roller shaft (34) on both sides.

8. The aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube production apparatus as described in claim 3, characterized in that: The mounting heads (37) mounted on the two torque shafts (35) are arranged in a staggered manner. The mounting heads (37) are cam-type structures. The length of the conveyor shaft (38) rotatably mounted on the mounting head (37) is allowed to form an 'X' cross structure.

9. The aerospace-grade high-pressure, low-temperature, and corrosion-resistant austenitic seamless stainless steel tube production apparatus as described in claim 4, characterized in that: The load claw plate (43) has an 'L' shaped structure. The load claw plate (43) has a through groove that allows the limiting roller (45) to be rotated and installed. Several limiting bearing plates (46) fixedly installed on the two load claw plates (43) are arranged in an alternate manner. The limiting bearing plates (46) are rotatably installed on the bearing shaft. The limiting bearing plates (46) are arranged in an alternating 'X' shape.

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