High temperature heat treatment production line and high strength and toughness steel pipe for automobile hollow shaft applied thereto

Abstract

The present invention provides a high-temperature heat treatment production line and a high-strength and tough steel pipe for automobile hollow shafts applied thereto, which relates to the field of heat treatment technology, including a loading platform, a positive annealing heating zone, a rapid cooling zone, a slow cooling zone and a discharge platform, a conveying device is arranged between the loading platform and the discharge platform, the conveying device is used to convey the workpiece, and the positive annealing heating zone, the rapid cooling zone, and the slow cooling zone are arranged in sequence along the conveying direction of the conveying device, a front preheating ventilation section is arranged between the loading platform and the positive annealing heating zone, and a discharge ventilation section is arranged between the slow cooling zone and the discharge platform. In the present invention, the production line is provided with a positive annealing heating zone, and both normalizing and annealing can be performed in the positive annealing heating zone. During normalizing, the workpiece is rapidly cooled in the rapid cooling zone, and during annealing, the workpiece is slowly cooled in the slow cooling zone. The production line can realize both normalizing and annealing process treatments, and does not need to set up two heat treatment production lines, which reduces production costs, while reducing the space occupied by the production line and improving the land utilization rate of the factory building.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment, in particular to a high-temperature heat treatment production line and a high-strength and toughness steel pipe for automobile hollow shafts applied thereto. Background Art

[0002] Metal heat treatment is a process in which a metal workpiece is heated to a suitable temperature in a certain medium, kept at this temperature for a certain period of time, and then cooled at different speeds. Metal heat treatment is one of the important processes in mechanical manufacturing. It generally does not change the shape and overall chemical composition of the workpiece, but rather changes the internal microstructure of the workpiece, or changes the chemical composition of the workpiece surface, to impart or improve the performance of the workpiece.

[0003] The existing metal heat treatment process includes four basic processes: normalizing, annealing, quenching and tempering. Both normalizing and annealing processes involve heating the workpiece to a suitable temperature and then cooling it in the air. Normalizing has a faster cooling rate than annealing, which can refine the crystal grains of steel during a faster cooling process, thereby improving the strength and toughness of the material. Annealing is to slowly heat the metal to a certain temperature, keep it for a sufficient time, and then cool it at a suitable rate. Annealing has a slower cooling rate, and is usually cooled in the furnace.

[0004] At present, due to different cooling methods, a normalizing furnace is required for normalizing a workpiece, and an annealing furnace is required for annealing a workpiece. Therefore, the existing heat treatment production line needs to set up a normalizing production line and an annealing production line separately, which increases production costs and occupies a large space. Summary of the invention

[0005] The present invention provides a high-temperature heat treatment production line and a high-strength and toughness steel pipe for automobile hollow shafts applied thereto, so as to solve the technical problem that the existing heat treatment production line needs to separately set up a normalizing production line and an annealing production line, which increases the production cost and occupies a large space.

[0006] In order to solve the above technical problems, the present invention discloses a high-temperature heat treatment production line, comprising: a loading platform, a positive annealing heating zone, a rapid cooling zone, a slow cooling zone and a unloading platform, a conveying device is arranged between the loading platform and the unloading platform, the conveying device is used to convey the workpiece, and the positive annealing heating zone, the rapid cooling zone and the slow cooling zone are arranged in sequence along the conveying direction of the conveying device, a front preheating ventilation section is arranged between the loading platform and the positive annealing heating zone, and a discharge ventilation section is arranged between the slow cooling zone and the unloading platform.

[0007] Preferably, a loading roller is provided on the loading platform, and a discharging roller is provided on the discharging platform.

[0008] Preferably, the positive annealing heating zone includes a main heating furnace, and a first ignition burner is arranged on both sides of the furnace door of the main heating furnace close to the front preheating ventilation section. A heating zone 1, a heating zone 2, a uniform heating zone 1, and a uniform heating zone 2 are arranged in sequence in the main heating furnace. A heating device is arranged on the main heating furnace, and the heating device is used to heat the workpiece passing through.

[0009] Preferably, the rapid cooling zone includes a rapid cooling furnace body, in which a rapid cooling zone 1 and a rapid cooling zone 2 are sequentially arranged, a first sealed interlayer is arranged on the side wall of the rapid cooling furnace body, a coolant is arranged in the first sealed interlayer, a first circulating refrigeration device is arranged outside the rapid cooling furnace body, the first circulating refrigeration device and the first sealed interlayer form a first circulating loop, the first circulating refrigeration device is used for circulating refrigeration of the coolant in the first sealed interlayer, a heat exchange chamber is arranged on the rapid cooling furnace body, a centrifugal fan and a heat exchanger are arranged in the heat exchange chamber, two groups of wind knives are arranged in the rapid cooling furnace body, the wind knives are distributed on the upper and lower sides of the conveying device, and the heat exchange chamber is connected with the wind knives through an air duct.

[0010] Preferably, the slow cooling zone includes a slow cooling furnace body, a second ignition burner is arranged on both sides of the furnace door of the slow cooling furnace body close to the discharge and ventilation section, a slow cooling zone 1, a slow cooling zone 2 and a slow cooling zone 3 are arranged in sequence in the slow cooling furnace body, a second sealed interlayer is arranged on the side wall of the slow cooling furnace body, a coolant is arranged in the second sealed interlayer, a second circulating refrigeration device is arranged outside the slow cooling furnace body, the second circulating refrigeration device and the second sealed interlayer form a second circulating loop, and the second circulating refrigeration device is used for circulating refrigeration of the coolant in the second sealed interlayer.

[0011] Preferably, the conveying device includes a plurality of conveying rollers, and a plurality of guide devices are arranged in the rapid cooling furnace body. The guide devices are arranged at intervals, and the guide device is located between two adjacent conveying rollers in the rapid cooling furnace body. The guide device is used to guide the conveyed workpiece, and the guide device includes a fixed ring, and fixed columns are symmetrically arranged on the front and rear sides of the fixed ring. The fixed column is connected to the inner wall of the rapid cooling furnace body away from the fixed ring. A rotating ring is arranged on the inner side of the fixed ring, and the outer wall of the rotating ring is rotatably connected to the inner wall of the fixed ring. A guide ring is arranged in the center of the rotating ring, and one side of the guide ring is connected to the side wall of the rotating ring through an annular baffle. The fixed ring, the rotating ring and the guide ring are concentrically arranged.

[0012] Preferably, a plurality of sliding holes are arranged in the guide ring, and the plurality of sliding holes are distributed in a circular array about the center of the guide ring. A guide limit rod is slidably arranged in the sliding hole. A rotating drum is arranged at one end of the guide limit rod close to the rotating ring. The rotating drum is rotatably connected to the guide limit rod. A fixed plate is arranged on the guide limit rod. A first spring is sleeved on the guide limit rod, and the first spring is respectively connected to the guide ring and the fixed plate.

[0013] Preferably, a connecting hole is provided on the outer wall of the fixed ring, a protective shell is provided at the connecting hole, a driving gear is provided in the protective shell, a plurality of driving gears are connected through a driving shaft, one end of the driving shaft is connected to the output end of the driving motor outside the rapid cooling furnace body, a gear ring is provided on the outer wall of the rotating ring, the driving gear is meshed with the outer side of the gear ring, a plurality of protrusions are provided on the inner ring of the fixed ring, the plurality of protrusions are distributed in a ring array, guide inclined surfaces are provided on both sides of the protrusion, the side of the protrusion away from the fixed ring is provided as an arc surface, and the curvature of the arc surface is adapted to the local curvature of the guide ring, and one end of the rotating drum extends between two adjacent protrusions.

[0014] Preferably, a guide hole is provided at one end of the guide limit rod away from the rotating drum, a contact rod is slidably provided in the guide hole, and the contact rod is connected to the guide hole via a second spring.

[0015] A high-strength and toughness steel pipe for automobile hollow shaft is prepared by applying the above-mentioned high-temperature heat treatment production line.

[0016] The technical solution of the present invention has the following advantages: the present invention provides a high-temperature heat treatment production line and a high-strength and tough steel pipe for automobile hollow shafts applied thereto, which relates to the field of heat treatment technology, including a loading platform, a positive annealing heating zone, a rapid cooling zone, a slow cooling zone and a discharge platform, a conveying device is arranged between the loading platform and the discharge platform, the conveying device is used to convey the workpiece, and the positive annealing heating zone, the rapid cooling zone, and the slow cooling zone are arranged in sequence along the conveying direction of the conveying device, a front preheating ventilation section is arranged between the loading platform and the positive annealing heating zone, and a discharge ventilation section is arranged between the slow cooling zone and the discharge platform. In the present invention, the production line is provided with a positive annealing heating zone, and both normalizing and annealing can be carried out in the positive annealing heating zone. During normalizing, the workpiece is rapidly cooled in the rapid cooling zone, and during annealing, the workpiece is slowly cooled in the slow cooling zone. The production line can realize both normalizing and annealing process treatments, and does not need to set up two heat treatment production lines, which reduces production costs, while reducing the space occupied by the production line and improving the land utilization rate of the factory building.

[0017] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the devices particularly pointed out in the written description and the drawings of the description.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0020] Figure 1 This is a schematic diagram of the high temperature heat treatment production line layout of the present invention;

[0021] Figure 2 It is a schematic longitudinal section diagram of a high temperature heat treatment production line of the present invention;

[0022] Figure 3 It is a schematic diagram of the medium-speed cooling furnace body of the present invention;

[0023] Figure 4 It is a schematic diagram of the internal structure of the guide device in the present invention;

[0024] Figure 5 For the present invention Figure 4 A magnified view of the structure at center;

[0025] Figure 6 For the present invention Figure 4 Enlarged view of the structure at point B in the middle.

[0026] In the figure: 1. Loading platform; 2. Annealing heating zone; 3. Rapid cooling zone; 4. Slow cooling zone; 5. Unloading platform; 6. Conveying device; 7. Pre-preheating ventilation section; 8. Discharging ventilation section; 9. Loading roller; 10. Unloading roller; 11. Heating main furnace; 12. Heating zone 1; 13. Heating zone 2; 14. Soaking zone 1; 15. Soaking zone 2; 16. Rapid cooling furnace body; 17. Rapid cooling zone 1; 18. Rapid cooling zone 2; 19. Heat exchange chamber; 20. Slow cooling zone Cold furnace body; 21. Slow cooling zone 1; 22. Slow cooling zone 2; 23. Slow cooling zone 3; 24. Conveying roller; 25. Guide device; 26. Fixed ring; 27. Fixed column; 28. Rotating ring; 29. ​​Guide ring; 30. Guide limit rod; 31. Rotating drum; 32. Fixed plate; 33. First spring; 34. Protective shell; 35. Drive gear; 36. Drive shaft; 37. Bump; 38. Contact rod; 39. Second spring; 40. Workpiece. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0028] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] Example 1

[0030] The embodiment of the present invention provides a high temperature heat treatment production line and a high strength and toughness steel pipe for automobile hollow shafts applied thereto, such as Figure 1-Figure 6 As shown, it includes: a loading platform 1, a positive annealing heating zone 2, a rapid cooling zone 3, a slow cooling zone 4 and a unloading platform 5. A conveying device 6 is arranged between the loading platform 1 and the unloading platform 5. The conveying device 6 is used to convey the workpiece 40. The positive annealing heating zone 2, the rapid cooling zone 3, and the slow cooling zone 4 are arranged in sequence along the conveying direction of the conveying device 6. A front preheating ventilation section 7 is arranged between the loading platform 1 and the positive annealing heating zone 2, and a discharging ventilation section 8 is arranged between the slow cooling zone 4 and the unloading platform 5.

[0031] The working principle and beneficial effects of the above technical solution are as follows: the loading of the workpiece 40 can be realized through the loading platform 1, and then the workpiece 40 is transported by the conveying device 6. The conveying device 6 adopts an existing roller conveyor, and the workpiece 40 is transported by a plurality of conveying rollers 24. The workpiece 40 first passes through the pre-preheating ventilation section 7 under the conveying of the conveying device 6, and enters the positive annealing heating zone 2 after preheating. In the positive annealing heating zone 2, the workpiece 40 can be heated at a high temperature. Both normalizing and annealing can be performed in the positive annealing heating zone 2. During normalizing, the workpiece 40 enters the rapid cooling zone 3 after being heated in the heating zone. The rapid cooling zone 3 can The workpiece 40 that has passed through the heating zone is quickly cooled. During annealing, after the workpiece 40 is heated in the heating zone, it enters the slow cooling zone 4 through the rapid cooling zone 3. When the workpiece 40 passes through the rapid cooling zone 3, the rapid cooling device of the rapid cooling zone 3 does not work, and the workpiece 40 will not be quickly cooled. Then the workpiece 40 is transported to the slow cooling zone 4 for slow cooling. Finally, the workpiece 40 passes through the discharge ventilation section 8 and arrives at the unloading platform 5, and the unloading is completed through the unloading platform 5. The production line can realize both normalizing and annealing process treatments, and there is no need to set up two heat treatment production lines, which reduces the production cost. At the same time, it reduces the space occupied by the production line and improves the land utilization rate of the factory building.

[0032] Example 2

[0033] On the basis of the above-mentioned embodiment 1, Figure 2 As shown, a loading roller 9 is arranged on the loading platform 1 , and a discharging roller 10 is arranged on the discharging platform 5 .

[0034] The working principle and beneficial effects of the above technical solution are as follows: by providing the loading roller 9 and the unloading roller 10, the transportation of the workpiece 40 is facilitated, and the labor intensity of the staff is reduced.

[0035] Example 3

[0036] On the basis of Example 1 or 2, Figure 2As shown, the positive annealing heating zone 2 includes a main heating furnace 11. The first ignition burners are arranged on both sides of the furnace door of the main heating furnace 11 close to the front preheating ventilation section 7. A heating zone 12, a heating zone 2 13, a uniform heating zone 14, and a uniform heating zone 2 15 are arranged in sequence in the main heating furnace 11. A heating device is arranged on the main heating furnace 11, and the heating device is used to heat the workpiece 40 passing through.

[0037] The working principle and beneficial effects of the above technical solution are as follows: the first ignition burner can burn the exhaust gas overflowing from the heating main furnace 11, thereby reducing exhaust gas emissions. After the workpiece 40 enters the heating main furnace 11, it passes through the heating zone 12, the heating zone 2 13, the uniform heating zone 14, and the uniform heating zone 2 15 in sequence. The heating device can complete the heating of the workpiece 40, so that the temperature of the workpiece 40 is uniform.

[0038] Example 4

[0039] On the basis of any one of Examples 1-3, Figure 2 As shown, the rapid cooling zone 3 includes a rapid cooling furnace body 16, in which a rapid cooling zone 17 and a rapid cooling zone 2 18 are sequentially arranged, a first sealed interlayer is arranged on the side wall of the rapid cooling furnace body 16, a coolant is arranged in the first sealed interlayer, a first circulating refrigeration device is arranged outside the rapid cooling furnace body 16, the first circulating refrigeration device and the first sealed interlayer form a first circulating loop, the first circulating refrigeration device is used for circulating refrigeration of the coolant in the first sealed interlayer, a heat exchange chamber 19 is arranged on the rapid cooling furnace body 16, a centrifugal fan and a heat exchanger are arranged in the heat exchange chamber 19, two groups of wind knives are arranged in the rapid cooling furnace body 16, the wind knives are distributed on the upper and lower sides of the conveying device 6, and the heat exchange chamber 19 is connected with the wind knives through an air duct.

[0040] The working principle and beneficial effects of the above technical solution are as follows: when the workpiece 40 is normalized, the workpiece 40 enters the rapid cooling furnace body 16, and the centrifugal fan and the heat exchanger in the heat exchange chamber 19 work, so that the cooling gas can enter the air duct through the heat exchange chamber 19, and then blow to the workpiece 40 transported on the conveying device 6 through the air knife, so as to achieve rapid cooling of the workpiece 40;

[0041] When the workpiece 40 is annealed, the centrifugal classifier and heat exchanger in the heat exchange chamber 19 stop working, ensuring a slow cooling of the workpiece 40;

[0042] The operation of the first circulating refrigeration device can drive the circulation of the cooling liquid in the first sealing interlayer and refrigerate the cooling liquid passing through, thereby reducing the temperature of the rapid cooling furnace body 16 and assisting in cooling the atmosphere in the rapid cooling furnace body 16 .

[0043] Example 5

[0044] On the basis of any one of Examples 1-4, Figure 2As shown, the slow cooling zone 4 includes a slow cooling furnace body 20, and second ignition burners are arranged on both sides of the furnace door of the slow cooling furnace body 20 close to the discharge ventilation section 8, a slow cooling zone 1 21, a slow cooling zone 22 and a slow cooling zone 3 23 are arranged in sequence in the slow cooling furnace body 20, a second sealed interlayer is arranged on the side wall of the slow cooling furnace body 20, a coolant is arranged in the second sealed interlayer, a second circulating refrigeration device is arranged outside the slow cooling furnace body 20, the second circulating refrigeration device and the second sealed interlayer form a second circulating loop, and the second circulating refrigeration device is used for circulating refrigeration of the coolant in the second sealed interlayer.

[0045] The working principle and beneficial effects of the above technical solution are as follows: after the workpiece 40 enters the slow cooling furnace body 20, it passes through the slow cooling zone 1 21, the slow cooling zone 22, and the slow cooling zone 3 23 in sequence, and the atmosphere in the slow cooling furnace body 20 is slowly cooled down. The operation of the second circulation refrigeration device can drive the circulation of the coolant in the second sealing interlayer and cool the passing coolant, thereby reducing the temperature of the slow cooling furnace body 20 and assisting in cooling the atmosphere in the slow cooling furnace body 20.

[0046] Example 6

[0047] On the basis of Example 4, Figure 2-Figure 6 As shown, the conveying device 6 includes a plurality of conveying rollers 24, and a plurality of guide devices 25 are arranged in the rapid cooling furnace body 16. The guide devices 25 are arranged at intervals, and the guide device 25 is located between two adjacent conveying rollers 24 in the rapid cooling furnace body 16. The guide device 25 is used to guide the conveyed workpiece 40, and the guide device 25 includes a fixed ring 26, and fixed columns 27 are symmetrically arranged on the front and rear sides of the fixed ring 26. The fixed column 27 is connected to the inner wall of the rapid cooling furnace body 16 away from the fixed ring 26. A rotating ring 28 is arranged on the inner side of the fixed ring 26, and the outer wall of the rotating ring 28 is rotatably connected to the inner wall of the fixed ring 26. A guide ring 29 is arranged in the center of the rotating ring 28, and one side of the guide ring 29 is connected to the side wall of the rotating ring 28 through an annular baffle. The fixed ring 26, the rotating ring 28 and the guide ring 29 are concentrically arranged.

[0048] The working principle and beneficial effects of the above technical solution are as follows: a plurality of conveying rollers 24 are arranged in the rapid cooling furnace body 16, and the conveying rollers 24 can convey the workpiece 40 through the rapid cooling furnace body 16 so as to realize rapid cooling during normalizing. The workpiece 40 is a steel pipe. Since the steel pipe is long, it is inevitable that the workpiece 40 will deviate during the conveying process, resulting in the problem of conveying jam. Therefore, a guide device 25 is arranged between two adjacent conveying rollers 24, and the guide device 25 can provide guidance for the conveyed workpiece 40. The workpiece 40 passes through the guide ring 29 and moves in the center of the guide ring 29. The diameter of the guide ring 29 is slightly larger than the diameter of the workpiece 40. The inner ring of the guide ring 29 can be used to limit different points of the workpiece 40 to prevent the workpiece 40 from being offset and stuck during transportation, thereby ensuring that the workpiece 40 can smoothly pass through the rapid cooling zone 3. The guide ring 29, the annular baffle and the rotating ring 28 are designed in one piece, which can improve the reliability of the connection between the guide ring 29, the annular baffle and the rotating ring 28. The rotating ring 28 rotates in the fixed ring 26. When the rotating ring 28 rotates, it can drive the guide ring 29 to rotate through the annular baffle.

[0049] Example 7

[0050] On the basis of Example 6, Figure 4-Figure 6 As shown, a plurality of sliding holes are arranged in the guide ring 29, and the plurality of sliding holes are distributed in a circular array about the center of the guide ring 29. A guide limit rod 30 is slidably arranged in the sliding hole. A rotating cylinder 31 is arranged at one end of the guide limit rod 30 close to the rotating ring 28. The rotating cylinder 31 is rotatably connected to the guide limit rod 30. A fixing plate 32 is arranged on the guide limit rod 30. A first spring 33 is sleeved on the guide limit rod 30. The first spring 33 is respectively connected to the guide ring 29 and the fixing plate 32.

[0051] The working principle and beneficial effects of the above technical scheme are as follows: in order to further prevent the workpiece 40 from being offset, a plurality of sliding holes are arranged on the guide ring 29, and the number of sliding holes is no less than three. A guide limit rod 30 is slidably arranged in the sliding hole, and one end of the guide limit rod 30 extends to the inside of the guide ring 29. The guide limit rod 30 is distributed in a ring array on the outside of the workpiece 40. There is a gap between the end of the guide limit rod 30 and the workpiece 40. The end of the guide limit rod 30 can make point contact with the outside of the workpiece 40, and the workpiece 40 is guided by multiple points during transportation to prevent the workpiece 40 from being offset during transportation. Large-area contact with the workpiece 40 is avoided while guiding, thereby ensuring the heat treatment effect of the workpiece 40 and improving the production quality of the workpiece 40.

[0052] Example 8

[0053] On the basis of Example 7, Figure 4-Figure 6As shown, a connecting hole is provided on the outer wall of the fixed ring 26, a protective shell 34 is provided at the connecting hole, a driving gear 35 is provided in the protective shell 34, a plurality of driving gears 35 are connected through a driving shaft 36, one end of the driving shaft 36 is connected to the output end of the driving motor outside the rapid cooling furnace body 16, a gear ring is provided on the outer wall of the rotating ring 28, the driving gear 35 meshes with the outer side of the gear ring, a plurality of protrusions 37 are provided on the inner ring of the fixed ring 26, the plurality of protrusions 37 are distributed in a ring array, guiding inclined surfaces are provided on both sides of the protrusion 37, a side of the protrusion 37 away from the fixed ring 26 is provided as an arc surface, and the arc surface curvature is adapted to the local curvature of the guide ring 29, and one end of the rotating drum 31 extends between two adjacent protrusions 37;

[0054] A guide hole is arranged at one end of the guide limit rod 30 away from the rotating drum 31 , and a contact rod 38 is slidably arranged in the guide hole. The contact rod 38 is connected to the guide hole through a second spring 39 .

[0055] The working principle and beneficial effects of the above technical solution are as follows: the rotation of the driving motor can drive the driving shaft 36 to rotate, the rotation of the driving shaft 36 can drive the multiple removal gears to rotate, the engagement of the driving gear 35 with the gear ring can drive the rotating ring 28 to rotate inside the fixed ring 26, the rotating ring 28 drives the guide ring 29 to rotate through the annular baffle, and the guide ring 29 drives the guide limit rod 30 to rotate when it rotates, so that the rotating drum 31 can pass through the protrusions 37, and the number of protrusions 37 is the same as the number of the rotating drum 31. When the rotating drum 31 passes through the protrusions 37, it first moves gradually along the guide inclined surface of the protrusion 37 to the arc surface of the protrusion 37. At the same time, the rotating drum 31 drives the guide limit rod 30 to slide toward the workpiece 40. When the rotating drum 31 moves to the arc surface, the contact rod 38 contacts the outside of the workpiece 40, and the second spring 39 is compressed. At this time, the rotating ring 28 continues to rotate to drive the guide limit rod 30 to rotate. The rotation of the positioning rod 30 drives the contact rod 38 to rotate. The contact between the plurality of contact rods 38 and the outside of the workpiece 40 can drive the workpiece 40 to rotate synchronously, so that the workpiece 40 rotates by a preset angle. Then, when the rotating drum 31 moves to separate from the arc surface and moves away from the protrusion 37 along the guide inclined surface, the contact rod 38 gradually separates from the workpiece 40, and the workpiece 40 can continue to be conveyed by the conveying roller 24. The above scheme can make the workpiece 40 rotate intermittently during the conveying process, which is convenient for comprehensive cooling of different positions of the workpiece 40, and solves the problem that the contact position between the workpiece 40 and the conveying roller 24 is not easy to cool, so that the workpiece 40 is cooled more evenly and quickly, and the cooling efficiency of the workpiece 40 is improved. By setting up a plurality of guide devices 25, the contact rod 38 can contact different positions of the workpiece 40, which is convenient for the rotation of the workpiece 40, and the workpiece 40 will not be damaged due to uneven force at a certain position, thereby improving the production quality.

[0056] A high-strength and tough steel pipe for automobile hollow shafts is prepared using the above-mentioned high-temperature heat treatment production line. The preparation process does not require two heat treatment production lines, which reduces production costs, while reducing the space occupied by the production line and improving the land utilization rate of the factory building.

[0057] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. High temperature heat treatment production line, characterized in that: include: A loading platform (1), a positive annealing heating zone (2), a rapid cooling zone (3), a slow cooling zone (4) and a discharging platform (5); a conveying device (6) is arranged between the loading platform (1) and the discharging platform (5); the conveying device (6) is used to convey a workpiece (40); the positive annealing heating zone (2), the rapid cooling zone (3) and the slow cooling zone (4) are arranged in sequence along the conveying direction of the conveying device (6); a front preheating ventilation section (7) is arranged between the loading platform (1) and the positive annealing heating zone (2); and a discharge ventilation section (8) is arranged between the slow cooling zone (4) and the discharging platform (5); The rapid cooling zone (3) comprises a rapid cooling furnace body (16), wherein a rapid cooling zone 1 (17) and a rapid cooling zone 2 (18) are sequentially arranged in the rapid cooling furnace body (16), a first sealing interlayer is arranged on the side wall of the rapid cooling furnace body (16), a cooling liquid is arranged in the first sealing interlayer, a first circulating refrigeration device is arranged outside the rapid cooling furnace body (16), the first circulating refrigeration device and the first sealing interlayer form a first circulating loop, the first circulating refrigeration device is used for circulating refrigeration of the cooling liquid in the first sealing interlayer, a heat exchange chamber (19) is arranged on the rapid cooling furnace body (16), a centrifugal fan and a heat exchanger are arranged in the heat exchange chamber (19), two groups of air knives are arranged in the rapid cooling furnace body (16), the air knives are distributed on the upper and lower sides of the conveying device (6), and the heat exchange chamber (19) is connected to the air knives through an air duct; The conveying device (6) comprises a plurality of conveying rollers (24). A plurality of guiding devices (25) are arranged in the rapid cooling furnace body (16). The guiding devices (25) are arranged at intervals. The guiding device (25) is located between two adjacent conveying rollers (24) in the rapid cooling furnace body (16). The guiding device (25) is used to guide the conveyed workpiece (40). The guiding device (25) comprises a fixed ring (26). Fixed columns (27) are symmetrically arranged on the front and rear sides of the fixed ring (26). The end of the fixed column (27) away from the fixed ring (26) is connected to the inner wall of the rapid cooling furnace body (16). A rotating ring (28) is arranged on the inner side of the fixed ring (26). The outer wall of the rotating ring (28) is rotatably connected to the inner wall of the fixed ring (26). A guiding ring (29) is arranged at the center of the rotating ring (28). One side of the guiding ring (29) is connected to the side wall of the rotating ring (28) through an annular baffle. The fixed ring (26), the rotating ring (28) and the guiding ring (29) are arranged concentrically. A plurality of sliding holes are arranged in the guide ring (29), and the plurality of sliding holes are distributed in a circular array about the center of the guide ring (29). A guide limit rod (30) is slidably arranged in the sliding hole. A rotating cylinder (31) is arranged at one end of the guide limit rod (30) close to the rotating ring (28). The rotating cylinder (31) is rotatably connected to the guide limit rod (30). A fixing plate (32) is arranged on the guide limit rod (30). A first spring (33) is sleeved on the guide limit rod (30), and the first spring (33) is respectively connected to the guide ring (29) and the fixing plate (32). A connecting hole is provided on the outer wall of the fixed ring (26), a protective shell (34) is provided at the connecting hole, a driving gear (35) is provided in the protective shell (34), a plurality of driving gears (35) are connected via a driving shaft (36), one end of the driving shaft (36) is connected to an output end of a driving motor outside the rapid cooling furnace body (16), a gear ring is provided on the outer wall of the rotating ring (28), the driving gear (35) meshes with the outer side of the gear ring, a plurality of protrusions (37) are provided on the inner ring of the fixed ring (26), the plurality of protrusions (37) are distributed in a ring array, guiding inclined surfaces are provided on both sides of the protrusions (37), a side of the protrusion (37) away from the fixed ring (26) is provided as an arc surface, and the arc surface curvature is adapted to the local arc of the guide ring (29), and one end of the rotating cylinder (31) extends between two adjacent protrusions (37); A guide hole is provided at one end of the guide limit rod (30) away from the rotating drum (31), a contact rod (38) is slidably arranged in the guide hole, and the contact rod (38) is connected to the guide hole via a second spring (39).

2. The high temperature heat treatment production line according to claim 1, characterized in that: A loading roller conveyor (9) is arranged on the loading platform (1), and a discharging roller conveyor (10) is arranged on the discharging platform (5).

3. The high temperature heat treatment production line according to claim 1, characterized in that: The positive annealing heating zone (2) comprises a main heating furnace (11). A first ignition burner is arranged on both sides of a furnace door of the main heating furnace (11) close to the front preheating ventilation section (7). A first heating zone (12), a second heating zone (13), a first uniform heating zone (14), and a second uniform heating zone (15) are arranged in sequence in the main heating furnace (11). A heating device is arranged on the main heating furnace (11), and the heating device is used to heat a workpiece (40) passing through.

4. The high temperature heat treatment production line according to claim 1, characterized in that: The slow cooling zone (4) comprises a slow cooling furnace body (20), a second ignition burner is arranged on both sides of the furnace door of the slow cooling furnace body (20) close to the discharge ventilation section (8), a slow cooling zone 1 (21), a slow cooling zone 2 (22) and a slow cooling zone 3 (23) are arranged in sequence in the slow cooling furnace body (20), a second sealing interlayer is arranged on the side wall of the slow cooling furnace body (20), a cooling liquid is arranged in the second sealing interlayer, a second circulating refrigeration device is arranged outside the slow cooling furnace body (20), the second circulating refrigeration device and the second sealing interlayer form a second circulating loop, and the second circulating refrigeration device is used for circulating cooling of the cooling liquid in the second sealing interlayer.

5. A high-strength steel tube for automobile hollow shaft, characterized in that: The method is prepared using the high temperature heat treatment production line described in any one of claims 1 to 4.

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