Stainless steel welded pipe heat treatment equipment

Abstract

The invention discloses stainless steel welded pipe heat treatment equipment, and relates to the technical field of pipe heat treatment, the stainless steel welded pipe heat treatment equipment comprises a heating unit and a cooling unit, the heating unit comprises a heating control cabinet and an electromagnetic induction coil; the cooling unit comprises a cooling furnace, a cooling channel and a cooling liquid cavity are formed in the furnace, the cooling channel axially penetrates through the cooling furnace, the cooling liquid cavity is formed in the peripheral side of the cooling channel, and the cooling channel and the center axis of the electromagnetic induction coil are located on the same straight line; end covers are hermetically connected to two ends of the cooling channel, and ports through which to-be-processed welded pipes pass are formed in the centers of the end covers; the cooling liquid cavity is communicated to the refrigerating device through a pipeline, the cooling channel is communicated with a vacuum pump and a protective gas pump through a pipeline, and the protective gas pump is used for introducing cooling protective gas into the cooling channel. The equipment has the advantages of being small in size, fast in temperature rise, efficient and energy-saving, the heat treatment quality of the stainless steel welded pipe can be remarkably improved, and the mechanical performance and corrosion resistance of the stainless steel welded pipe are enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of heat treatment of pipe fittings, and in particular relates to heat treatment equipment for stainless steel welded pipes. Background Art

[0002] During the production process of stainless steel welded pipes, they need to be heat treated. Heat treatment can significantly improve the mechanical properties and corrosion resistance of the welded pipes, help extend the service life of the welded pipes, and ensure their reliability and safety under various working conditions.

[0003] In the prior art, normalizing or annealing treatment is usually used to change the material structure of stainless steel welded pipes to improve their mechanical properties and corrosion resistance. However, the prior art stainless steel welded pipe heat treatment equipment has the following technical defects: 1. Poor heating uniformity. Although the prior art can improve the heating uniformity to a certain extent by rotating the welded pipe, it still faces the problem of uneven heating; 2. The speed control of the cooling process is not ideal. The speed control of the cooling process has a huge impact on the quality of the welded pipe. Rapid cooling may cause the internal stress of the welded pipe to increase, thereby reducing the mechanical properties of the material. Therefore, it is a challenge to accurately control the cooling rate and set the cooling method; 3. The equipment has high energy consumption. Continuously heating the welded pipe requires a lot of energy. The development of a more energy-saving and efficient heating and cooling system is the key to improving the competitiveness of the equipment; 4. The equipment has a low degree of automation. In order to obtain better quality of welded pipes, higher precision temperature control and speed regulation are required to ensure the heat treatment quality of the welded pipe. It has become a technical problem in this field to realize full automation and precise control of the entire process.

[0004] In view of this, a stainless steel welded pipe heat treatment equipment is urgently needed to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a stainless steel welded pipe heat treatment equipment to solve the above technical problems existing in the prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following scheme: a stainless steel welded pipe heat treatment equipment, comprising a heating unit and a cooling unit, the heating unit comprising a heating control cabinet and an electromagnetic induction coil fixedly connected to one side of the heating control cabinet; the cooling unit comprising a cooling furnace, the interior of the cooling furnace is provided with a cooling channel and a cooling liquid chamber, the cooling channel axially penetrates the cooling furnace, the cooling liquid chamber is arranged on the outer peripheral side of the cooling channel, the cooling channel and the central axis of the electromagnetic induction coil are located on the same straight line; the two ends of the cooling channel are sealed with end covers, the center of the end cover is provided with a port for accommodating the passage of the welded pipe to be processed, and the welded pipe to be processed is elastically sealed with the port in a circumferential direction; the cooling liquid chamber pipeline is connected to a refrigeration device, the cooling channel pipeline is connected with a vacuum pump and a shielding gas pump, and the shielding gas pump is used to introduce cooling shielding gas into the cooling channel.

[0007] Preferably, a medium frequency induction heating power supply is provided in the heating control cabinet, and both ends of the electromagnetic induction coil are connected to the medium frequency induction heating power supply.

[0008] Preferably, the medium frequency induction heating power supply is a DSP+IGBT fully air-cooled medium frequency electromagnetic induction heater, and the heating temperature range of the electromagnetic induction coil is 0 to 1100°C.

[0009] Preferably, the end covers are detachably mounted on both ends of the cooling furnace via flanges.

[0010] Preferably, a rubber ring is provided at the port of the end cover.

[0011] Preferably, a cooling liquid inlet and a cooling liquid outlet which penetrate into the cooling liquid chamber are respectively provided near both ends of the circumference of the cooling furnace.

[0012] Preferably, the protective gas pump is connected to a gas source, and the cooling protective gas stored in the gas source is hydrogen.

[0013] Preferably, the vacuum pump and the protective gas pump are respectively connected to the cooling channel through ventilation pipes near the two ends of the cooling furnace, and valves are provided on both ventilation pipes.

[0014] Preferably, the cooling furnace is also connected to an intelligent control system, and the vacuum pump, the protective gas pump and the refrigeration device are all electrically connected to the intelligent control system.

[0015] Preferably, a vacuum gauge and a temperature sensor are provided in the cooling channel, and both the vacuum gauge and the temperature sensor are electrically connected to the intelligent control system.

[0016] The present invention discloses the following technical effects:

[0017] The present invention proposes a stainless steel welded pipe heat treatment equipment, which first uses an electromagnetic induction coil to heat the stainless steel welded pipe to 1050°C, and then cools it under hydrogen protection, and achieves efficient and stable heat treatment of the stainless steel welded pipe through precise heating and cooling control and effective gas protection measures. The equipment of the present invention has the advantages of small size, fast heating, high efficiency and energy saving. Compared with traditional stainless steel welded pipe heat treatment equipment, it can significantly improve the heat treatment quality of stainless steel welded pipes and enhance their mechanical properties and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a front view of the heat treatment equipment according to an embodiment of the present invention;

[0020] Figure 2 A top view of a heat treatment device according to an embodiment of the present invention;

[0021] Figure 3 It is a right side view of the heat treatment equipment according to an embodiment of the present invention;

[0022] Figure 4 Axonometric view of the heat treatment equipment according to the embodiment of the present invention Figure 1 ;

[0023] Figure 5 Axonometric view of the heat treatment equipment according to the embodiment of the present invention Figure 2 ;

[0024] Figure 6 It is an internal cross-sectional view of a cooling furnace in a heat treatment device according to an embodiment of the present invention;

[0025] In the figure: 1. working platform; 2. electromagnetic induction coil; 3. heating control cabinet; 4. vacuum tube; 5. valve one; 6. vacuum pump; 7. protective gas pump; 8. valve two; 9. air inlet pipe; 10. welding pipe to be processed; 11. first flange; 12. coolant outlet; 13. cooling furnace; 14. coolant inlet; 15. second flange; 16. end cover; 17. mounting clamp; 18. mounting seat; 19. furnace body flange; 20. countersunk screw hole; 21. first air port; 22. second air port; 23. end cover assembly groove; 24. coolant chamber; 25. cooling channel. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Reference Figure 1 As shown, the present invention provides a stainless steel welded pipe heat treatment equipment, including a heating unit and a cooling unit; the heating unit includes a heating control cabinet 3 fixedly connected to an operating platform 1, and an electromagnetic induction coil 2 is led out from one side of the heating control cabinet 3; the cooling unit includes a cooling furnace 13, the cooling furnace 13 is a cylindrical furnace body, the central axis of the cooling furnace 13 and the electromagnetic induction coil 2 coincide on a straight line, the cooling furnace 13 is fixed to the operating platform 1 on one axial side of the electromagnetic induction coil 2 through a mounting seat 18 and a mounting clamp 17, a cooling channel 25 and a cooling liquid chamber 24 are arranged inside the cooling furnace 13, the cooling channel 25 axially penetrates the cooling furnace 13, and the cooling liquid chamber 24 is arranged on the outer peripheral side of the cooling channel 25, that is, the cooling furnace 13 It is a double-layer structure, the inner layer is a cooling channel 25, and the two ends of the cooling channel 25 are open, and the outer layer is a cooling liquid chamber 24, which is a closed space; the two ends of the cooling channel 25 are sealed with end covers 16, and the center of the end cover 16 is provided with a port for accommodating the welding pipe 10 to be processed, and the welding pipe 10 to be processed is elastically sealed with the port in the circumferential direction; the cooling liquid chamber 24 has a cooling liquid inlet 14 and a cooling liquid outlet 12, and the cooling liquid inlet 14 and the cooling liquid outlet 12 are respectively connected to the refrigeration device through pipelines to form a water-cooled circulation system; the cooling channel 25 is connected to a vacuum pump 6 and a shielding gas pump 7 through two pipelines, and the shielding gas pump 7 is used to introduce cooling shielding gas into the cooling channel 25.

[0029] In the above embodiment, if Figure 3 and Figure 4 As shown, four mounting seats 18 are fixedly connected to the working platform 1, and the four mounting seats 18 are grouped in pairs. A mounting clamp 17 is connected to the top of each group of mounting seats 18 through a bracket. The cooling furnace 13 is fixed in the two mounting clamps 17, and the central axis of the cooling furnace 13 is ensured to be located on the extension line of the central axis of the electromagnetic induction coil 2, thereby ensuring that the welded pipe 10 to be processed can smoothly pass through the electromagnetic induction coil 2 and the cooling channel 25.

[0030] In the above embodiment, if Figure 4As shown, a heating control cabinet 3 is provided on the work platform 1, and a medium frequency induction heating power supply is provided in the heating control cabinet 3. The positive and negative poles of the medium frequency induction heating power supply are respectively connected to the two ends of the electromagnetic induction coil 2 through wires. When the alternating current of the medium frequency induction heating power supply passes through the electromagnetic induction coil 2, the electromagnetic induction coil 2 will generate a changing magnetic field. When the welded pipe is placed in this changing magnetic field, eddy currents will be induced inside the welded pipe. When these eddy currents flow inside the welded pipe, they are subjected to resistance and then generate heat, so that the welded pipe is evenly heated. The above structure uses an induction coil to heat the welded pipe, which has a fast heating speed and high efficiency, can achieve non-contact heating, and does not produce polluting gas.

[0031] It should be understood that the electromagnetic induction coil 2 is connected to a medium frequency induction heating power supply providing alternating current through a wire, and is connected to a frequency converter for adjusting its power and frequency.

[0032] According to a further optimization scheme, the medium frequency induction heating power supply is a DSP+IGBT fully air-cooled medium frequency electromagnetic induction heater. The electromagnetic induction coil 2 is heated by using the DSP+IGBT fully air-cooled medium frequency electromagnetic induction heater, and the heating temperature range can reach 1100°C.

[0033] In the above embodiment, if Figures 4 to 6 As shown, the cooling furnace 13 serves as the main structure of the cooling unit, and has an internal cooling liquid chamber 24. The cooling liquid chamber 24 is surrounded by an inner circular furnace body and an outer circular furnace body, and coolant flows inside. The coolant flows in from the cooling liquid inlet 14 on one side of the outer circular furnace body, absorbs the heat conducted by the inner circular furnace body, and then flows out through the cooling liquid outlet 12 on the other side of the outer circular furnace body. Then, it is circulated and cooled in the refrigeration device and flows into the cooling liquid inlet 14, thereby forming a refrigeration cycle system.

[0034] like Figure 6 As shown, the center of the inner circular furnace body is hollow and the two ends are open, forming a cooling channel 25 for accommodating the welded pipe 10 to be processed. The cooling channel 25 is used as a region for local cooling of the welded pipe 10 to be processed. A protective gas pump 7 for providing reducing gas to the cooling channel 25 and a vacuum pump 6 for extracting excess gas in the cooling channel 25 are connected through pipelines to control the atmosphere and pressure of the cooling area. In order to accurately control the pressure of the cooling channel 25, a vacuum gauge is connected in the cooling channel 25. The vacuum gauge is used to measure the vacuum degree and air pressure in the chamber, and provides a reference for accurately controlling the temperature and pressure in the cooling channel 25. The first flange 11 and the second flange 15 for sealing the cooling channel 25 are connected at both ends of the cooling furnace 13. Specifically, a furnace body flange 19 is fixedly connected at both ends of the cooling furnace 13. A plurality of countersunk screw holes 20 are evenly distributed on the circumference of the furnace body flange 19. The first flange 11 and the second flange 15 are adapted to the furnace body flange 19, and are fastened by bolts to fix the end cover 16 at both ends of the cooling furnace 13.

[0035] In the embodiment of the present invention, the end cover 16 is detachably mounted on both ends of the cooling furnace 13 through the first flange 11 and the second flange 15. It should be understood that a sealing rubber ring is provided between the end cover 16 and the flanges on both sides, and a port for accommodating the welded pipe 10 to be processed is provided in the center of the end cover 16, and the welded pipe 10 to be processed is elastically sealed with the port in the circumferential direction. Specifically, a rubber ring is provided at the port of the end cover 16, and the rubber ring seals the outer circumference of the welded pipe 10 to be processed to form an elastic seal.

[0036] As a further optimization scheme, both ends of the cooling furnace 13 are provided with end cover assembly grooves 23 that are matched with the end covers 16 in size, so as to form a stable sealed connection.

[0037] like Figure 5 As shown, the protective gas pump 7 is connected to a gas source, in which cooling protective gas is stored. The protective gas pump 7 introduces protective gas into the cooling channel 25 through the air inlet pipe 9, wherein the introduced cooling protective gas is a reducing gas, which can prevent the surface oxidation of the welded pipe and reduce the intrusion of other impurities during the heat treatment process, thereby maintaining the purity of the material and improving the quality of the final product, such as hydrogen. One end of the air inlet pipe 9 is arranged on the inner circular furnace body to form an air inlet, and the other end passes through the cooling liquid chamber 24, is led out from the peripheral side of the outer circular furnace body and connected to the protective gas pump 7, and a valve 2 8 is provided on the air inlet pipe 9 located outside the cooling furnace 13.

[0038] The vacuum pump 6 is fixedly connected to the working platform 1 and enters the cooling channel 25 through the vacuum tube 4. One end of the vacuum tube 4 is arranged on the inner circular furnace body to form an exhaust port, and the other end passes through the cooling liquid chamber 24, is led out from the peripheral side of the outer circular furnace body and connected to the vacuum pump 6. A valve 5 is provided on the vacuum tube 4 located outside the cooling furnace 13. At the same time, a vacuum gauge can also be arranged on the vacuum tube 4 between the valve 5 and the cooling furnace 13.

[0039] To further optimize the solution, the cooling furnace 13 is also connected to an intelligent control system, and the vacuum pump 6, the protective gas pump 7, and the refrigeration device are all electrically connected to the intelligent control system.

[0040] In some embodiments, valve 1 5 and valve 2 8 can be configured as electronic valves and electrically connected to an intelligent control system.

[0041] In some embodiments, the cooling furnace 13 further includes a temperature control system, which includes a temperature sensor disposed in the cooling channel 25 and a PLC electrically connected to the refrigeration device. The temperature sensor is specifically a thermocouple disposed in the inner circular furnace body, which is used to measure the temperature and convert the temperature signal into an electrical signal. The PLC is used to receive and process these electrical signals, and control the operation of the refrigeration device according to a preset temperature control strategy to maintain the temperature value in the cooling channel 25 within a set range and cool at a set temperature drop rate.

[0042] The working principle of the embodiment of the present invention is as follows:

[0043] First, the welded pipe 10 to be processed is heat treated by the electromagnetic induction coil 2 to reach the set heat treatment temperature of 1050°C; then, the air in the cooling channel 25 is extracted by the vacuum pump 6, and hydrogen is introduced into the cooling channel 25 by the protective gas pump 7. The air pressure in the cooling channel 25 is measured by a vacuum gauge, and the air pressure is controlled to reach and remain within the set value range. The temperature sensor is used to monitor the temperature change in the cooling channel 25, and then the cooling rate is controlled, so that the welded pipe 10 to be processed after the heat treatment is cooled in a controllable atmosphere to achieve the metallurgical properties required by the material and improve the quality and consistency of the heat treatment.

[0044] The details not described in detail in the present invention are all conventional technical means known to those skilled in the art.

[0045] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0046] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A stainless steel welded pipe heat treatment equipment, characterized in that: The invention comprises a heating unit and a cooling unit, wherein the heating unit comprises a heating control cabinet (3) and an electromagnetic induction coil (2) fixedly connected to one side of the heating control cabinet (3); the cooling unit comprises a cooling furnace (13), wherein a cooling channel (25) and a cooling liquid chamber (24) are arranged inside the cooling furnace (13), wherein the cooling channel (25) axially penetrates the cooling furnace (13), the cooling liquid chamber (24) is arranged on the outer peripheral side of the cooling channel (25), and the cooling channel (25) and the electromagnetic induction coil (2 ) are located on the same straight line; both ends of the cooling channel (25) are sealedly connected with end covers (16), and a port for accommodating the welding pipe (10) to be processed is opened in the center of the end cover (16), and the welding pipe (10) to be processed is elastically sealed with the port in a circumferential direction; the cooling liquid chamber (24) pipeline is connected to the refrigeration device, and the cooling channel (25) pipeline is connected to the vacuum pump (6) and the protective gas pump (7), and the protective gas pump (7) is used to introduce cooling protective gas into the cooling channel (25).

2. The stainless steel welded pipe heat treatment equipment according to claim 1, characterized in that: A medium-frequency induction heating power supply is arranged in the heating control cabinet (3), and both ends of the electromagnetic induction coil (2) are connected to the medium-frequency induction heating power supply.

3. The stainless steel welded pipe heat treatment equipment according to claim 2, characterized in that: The medium frequency induction heating power supply is a DSP+IGBT fully air-cooled medium frequency electromagnetic induction heater, and the heating temperature range of the electromagnetic induction coil (2) is 0 to 1100°C.

4. The stainless steel welded pipe heat treatment equipment according to claim 1, characterized in that: The end covers (16) are detachably mounted on both ends of the cooling furnace (13) via flanges.

5. The stainless steel welded pipe heat treatment equipment according to claim 4, characterized in that: A rubber ring is provided at the port of the end cover (16).

6. The stainless steel welded pipe heat treatment equipment according to claim 1, characterized in that: A cooling liquid inlet (14) and a cooling liquid outlet (12) which are connected to the cooling liquid chamber (24) are respectively provided on the peripheral side of the cooling furnace (13) near both ends.

7. The stainless steel welded pipe heat treatment equipment according to claim 1, characterized in that: The protective gas pump (7) is connected to a gas source, and the cooling protective gas stored in the gas source is hydrogen.

8. The stainless steel welded pipe heat treatment equipment according to claim 1, characterized in that: The vacuum pump (6) and the protective gas pump (7) are respectively connected to the cooling channel (25) through ventilation pipes near the two ends of the cooling furnace (13), and valves are provided on the two ventilation pipes.

9. The stainless steel welded pipe heat treatment equipment according to claim 1, characterized in that: The cooling furnace (13) is also connected to an intelligent control system, and the vacuum pump (6), the protective gas pump (7) and the refrigeration device are all electrically connected to the intelligent control system.

10. The stainless steel welded pipe heat treatment equipment according to claim 9, characterized in that: A vacuum gauge and a temperature sensor are arranged in the cooling channel (25), and both the vacuum gauge and the temperature sensor are electrically connected to the intelligent control system.

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