Alloy steel hot rolling unit and using method thereof

Abstract

The invention discloses an alloy steel hot rolling unit and a using method thereof, and relates to the technical field of alloy steel rolling. The alloy steel hot rolling unit comprises a hot rolling mill, a metal frame is arranged on a hot rolling assembly line of the hot rolling mill, a sliding rail is arranged at the top of the metal frame, and a water cooling system and a transversely-fixed air cooling mechanism are slidably connected to the sliding rail; a main driving power box is arranged on the sliding rail and electrically connected with a water cooling system and an air cooling mechanism, the water cooling system comprises a water bin slidably connected to the sliding rail, a first water injection port and a second water injection port are formed in the side wall of one side of the water bin, and a second pump is arranged on the part, located in the water bin, of the second water injection port. A water tank is arranged on one side of the hot rolling mill, the automatic process of water cooling and air cooling is achieved, network carbides in alloy steel microstructures are eliminated, good microstructures are obtained through low-temperature slow cooling, and the effect of preparing for obtaining good heat treatment microstructures, hardness and other performance subsequently is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of alloy steel rolling, in particular to a steel alloy steel hot rolling mill unit and a use method thereof. Background Art

[0002] Mechanical blades are divided into steel-inserted blades and all-steel blades according to the manufacturing process. The weld strength between the blade steel and the blade body of the steel-inserted blade should meet certain requirements, and at the same time, it should have good impact resistance and creep resistance. In addition, the inlay process itself should be conducive to improving the organization and performance of the blade steel, and should not cause any damage to the microstructure. The current manufacturing of steel-inserted blades is mainly the method of hot-rolled welding steel-inserted. The method of inlaying alloy tool steel on the low-carbon steel blade body by high-temperature hot rolling can achieve a good combination of blade steel and blade body during hot rolling forming, and can meet the performance requirements of steel-inserted mechanical blades. Therefore, it is the main process method for steel-inserted mechanical blades. At present, my country's hot-rolled steel-inserted process for high-alloy steel and high-speed steel inlaid mechanical blades is at the international advanced level. However, the hot-rolled welding temperature is often difficult to control accurately, and the pressure is controlled by the combined factors of the pressure reduction and temperature, which also has different effects on the quality of hot-rolled welded steel-inserted blades. Therefore, domestic blade companies are still constantly exploring and improving the process technology of hot-rolled welding, and their process methods and effects are different.

[0003] In fact, the hot-rolled steel-inlaid process, which is the primary processing process in the production of steel-inlaid mechanical blades, faces two key problems due to its intermittent production mode: the first is that it requires low cost and high efficiency. Only by completing batch-specification blanks with low cost and high efficiency can they be quickly put into the subsequent production line for fine workmanship; the second is to improve the weld strength and ensure the quality of the blade steel, which is of self-evident importance for subsequent heat treatment.

[0004] Gas furnaces using natural gas as fuel have the characteristics of fast start-up, fast heating speed, and low energy consumption. They are also easy to control the air intake to achieve the purpose of temperature control and adjustment of the furnace atmosphere. However, due to the high carbon content or high alloy content of alloy tool steel, a fast heating speed or excessively high heating temperature can easily cause the alloy tool steel to overheat and burn. For a long time, the heating furnaces used in the mechanical blade industry have been coke or fuel oil, and many factories even use electric furnaces for heating to ensure that alloy tool steel does not overheat or burn to cause waste consumption. As a result, the production efficiency is low, which becomes a bottleneck restricting the process. In the subsequent heat treatment of alloy steel, it usually causes obvious network carbides on the surface of the alloy steel. Summary of the invention

[0005] The object of the present invention is to provide an alloy steel hot rolling mill and a method of using the same to solve the problems raised in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: an alloy steel hot rolling mill and a method for using the same, comprising a hot rolling mill, a metal frame is arranged on the hot rolling assembly line of the hot rolling mill, a sliding track is arranged on the top of the metal frame, a water cooling system and a transversely fixed air cooling mechanism are slidably connected on the sliding track, a total driving power supply box is arranged on the sliding track, and the total driving power supply box is electrically connected to the water cooling system and the air cooling mechanism; The water cooling system includes a water tank slidably connected to the sliding track, a first water injection port and a second water injection port are arranged on one side wall of the water tank, a second pump is arranged at the part of the second water injection port located in the water tank, and a water tank is arranged on one side of the hot rolling mill.

[0007] According to the above technical scheme, a first water-cooling pipe and a second water-cooling pipe are arranged at the top of the water tank and in the same row as the output end of the hot rolling mill, a first pump is arranged on the part of the first water-cooling pipe located in the water tank, the first water-cooling pipe and the second water-cooling pipe extend upward and are connected to a collecting pipe through the concentrated pipes, the collecting pipe extends upward and is symmetrically connected to the third water-cooling pipe and the fourth water-cooling pipe, the third water-cooling pipe is plug-connected to the first water injection port, the fourth water-cooling pipe is plug-connected to the second water injection port, a first intelligent valve is arranged on the third water-cooling pipe, and a second intelligent valve is arranged on the fourth water-cooling pipe.

[0008] According to the above technical solution, a water spray assembly is arranged in the middle area at the bottom of the water tank. The water spray assembly includes a groove arranged at the bottom of the water tank. A plurality of spray pipes are arranged at the bottom of the groove. Support rods are fixedly installed between adjacent spray pipes.

[0009] According to the above technical solution, the water spray assembly also includes a telescopic plate arranged on both sides of a plurality of spray pipes, the top of the telescopic plate is connected to the water tank pipe, and a plurality of intelligent mist nozzles are evenly arranged on the side wall of the telescopic plate from top to bottom.

[0010] According to the above technical scheme, the air cooling mechanism is divided into a top-mounted air cooling component arranged in the input end area of ​​the hot rolling mill and a transverse stepping transmission air cooling component arranged in the output end area of ​​the hot rolling mill. The top-mounted air cooling component includes a first fan casing arranged on the top of the water tank, the top pipe of the first fan casing is connected to the first air duct, the first air duct pipe is connected to the wind bin slidably arranged on the sliding track, the first air outlet is arranged at the bottom of the wind bin, and the first fan is arranged in the first fan casing.

[0011] According to the above technical solution, a first side wind plate is arranged in the input end area of ​​the hot rolling mill and on the side close to the water tank, a second air outlet is arranged on the first side wind plate toward the roller shaft matching the hot rolling mill, two second air ducts are arranged on the side wall of the first side wind plate, the two second air ducts are respectively connected to a first water storage tank, a second fan housing is arranged at the connection between each first water storage tank and the second air duct, and a second fan is arranged in each second fan housing.

[0012] According to the above technical solution, the lateral step-transfer air cooling component includes a convection bin connected to a water tank, a first convection tube and a second convection tube are arranged on the side wall of the convection bin, the first convection tube and the second convection tube are connected to the same second water storage bin, a plurality of third fan housings are arranged on the top of the second water storage bin, and a third fan is arranged in each third fan housing.

[0013] According to the above technical solution, the third fan is connected to the third air duct, the third air duct is connected to the second side air plates arranged on both sides of the output end area of ​​the hot rolling mill, and the third air outlet is arranged on the side wall of the second side air plate facing the hot rolling mill.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention, by providing a water cooling system and an air cooling mechanism, realizes an automated process of water cooling and air cooling, eliminates network carbides in the microstructure of the alloy steel, and obtains a good microstructure by slow cooling at low temperature, thereby achieving the effect of preparing for the subsequent acquisition of good heat treatment microstructure and hardness and other properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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: Figure 1 This is a schematic diagram of the overall front three-dimensional structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the overall front three-dimensional structure of the present invention. Figure 2 ; Figure 3 It is a schematic diagram of the water tank and water spray assembly of the present invention; Figure 4 is a schematic diagram of a first tuyere of the present invention; Figure 5 is a schematic diagram of a second tuyere of the present invention; Figure 6 The present invention Figure 2 A schematic diagram of the enlarged structure of the middle A area; In the figure: 1. hot rolling mill; 2. metal frame; 3. sliding track; 4. water cooling system; 5. air cooling mechanism; 6. water tank; 7. first water inlet; 8. second water inlet; 9. water tank; 10. first water cooling pipe; 11. second water cooling pipe; 12. manifold; 13. third water cooling pipe; 14. fourth water cooling pipe; 15. first intelligent valve; 16. second intelligent valve; 17. water spray assembly; 18. groove; 19. spray pipe; 20. support rod; 21. telescopic plate; 22. intelligent mist nozzle; 23. head space Cooling component; 24. Horizontal stepping transmission air cooling component; 25. First fan casing; 26. First air duct; 27. Wind bin; 28. First air outlet; 29. ​​First side air plate; 30. Second air duct; 31. First water storage tank; 32. Second fan casing; 33. Second air outlet; 34. Convection bin; 35. First convection duct; 36. Second convection duct; 37. Second water storage tank; 38. Third fan casing; 39. Third air duct; 40. Second side air plate; 41. Third air outlet; 42. Main driving power supply box. DETAILED DESCRIPTION

[0016] 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.

[0017] See also Figure 1-6 The present invention provides a technical solution: an alloy steel hot rolling mill and a method for using the same, comprising a hot rolling mill 1, a metal frame 2 is arranged on the hot rolling assembly line of the hot rolling mill 1, a sliding track 3 is arranged on the top of the metal frame 2, a water cooling system 4 and a transversely fixed air cooling mechanism 5 are slidably connected on the sliding track 3, a total driving power supply box 42 is arranged on the sliding track 3, the total driving power supply box 42 is electrically connected to the water cooling system 4 and the air cooling mechanism 5, and provides energy for the movement of the water cooling system 4 and the air cooling mechanism 5 on the sliding track 3; The water cooling system 4 includes a water tank 6 slidably connected to the sliding track 3, and pulley assemblies are arranged at the four corners of the bottom of the water tank 6. The pulley assembly enables the water tank 6 to move on the sliding track 3. A first water injection port 7 and a second water injection port 8 are arranged on a side wall of one side of the water tank 6. A second pump is arranged at the part of the second water injection port 8 located in the water tank 6. The cooling water in the water tank 6 is transported to the second water injection port 8 through the second pump. A water tank 9 is arranged on one side of the hot rolling mill 1. The water tank 9 has a high capacity characteristic, and a water inlet structure is arranged at the bottom thereof to continuously inject water into the water tank 9 to keep the cooling water amount inside the water tank 9 sufficient. At the same time, cooling pipes are evenly arranged on the bottom wall and side wall of the water tank 9. The cooling water inside the water tank 9 is cooled by the cooling pipes, and the cooling pipes extend from the bottom of the water tank 9 to connect with the cooling structure. In this embodiment, the cooling structure and the pulley assembly are both existing technical mechanisms and are not described in detail here. The water tank 9 is located far away from the hot rolling mill 1, which reduces the energy consumption of cooling the cooling pipe. A water spray assembly 17 is provided in the middle area at the bottom of the water tank 6, and its function is to spray out the cooling water in the water tank 6; A first water-cooling pipe 10 and a second water-cooling pipe 11 are arranged at the top of the water tank 9 and in the same row as the output end of the hot rolling mill 1. A first pump is arranged at the part of the first water-cooling pipe 10 located in the water tank 9, and the cooling water in the water tank 9 is transported to the first water-cooling pipe 10 through the pump. The first water-cooling pipe 10 and the second water-cooling pipe 11 extend upward and are connected to a collecting pipe 12 by a centralized pipeline. The collecting pipe 12 extends upward and is symmetrically connected to the third water-cooling pipe 13 and the fourth water-cooling pipe 14. The third water-cooling pipe 13 is plug-connected to the first water injection port 7, and the fourth water-cooling pipe 14 is plug-connected to the second water injection port 8. A first intelligent valve 15 is arranged on the third water-cooling pipe 13, and a second intelligent valve 16 is arranged on the fourth water-cooling pipe 14. In this embodiment, the collecting pipe 12, the third water-cooling pipe 13, and the fourth water-cooling pipe 14 are all telescopic pipes, which are connected by a plurality of short pipes, and are a prior art structure. Among them, the water tank 6 is controlled by the PLC system to move to a preset position, that is, above the output end of the hot rolling mill 1, so that the cooling water in the water tank 6 can be sprayed onto the alloy steel output by the hot rolling mill 1. When the position of the water tank 6 is confirmed, the manifold 12 is driven to be extended to a preset height, and then the third water-cooling pipe 13 and the fourth water-cooling pipe 14 are driven to be extended to the first water-cooling pipe 10 and the second water-cooling pipe 11, so that the third water-cooling pipe 13 is connected to the first water injection port 7, and the fourth water-cooling pipe 14 is connected to the second water injection port 8. Then the PLC system drives the first pump to operate, and the cooling water in the water tank 9 is transported to the first water-cooling pipe 10, enters the manifold 12 through the first water-cooling pipe 10, enters the third water-cooling pipe 13 through the manifold 12, and finally is transported into the water tank 6 through the first water injection port 7 until the water tank 6 is filled. In this process, the first intelligent valve 15 is opened and the second intelligent valve 16 is closed by the PLC system. At this time, the cooling water can be sprayed out by opening the water spray assembly 17 to cool the alloy steel below; When the water tank 6 is not moved to the preset position, the third water cooling pipe 13 and the fourth water cooling pipe 14 are in a shortened state, the purpose of which is to provide more space for people to move around, and the manifold 12 is also in a shortened state, the purpose of which is to provide space for the water cooling system 4 and the air cooling mechanism 5 to move on the sliding track 3; Among them, the PLC system pre-inputs the rolling times of the alloy steel this time, and divides it into alloy steel with low rolling times and alloy steel with high rolling times. If it is alloy steel with low rolling times, it means that the alloy steel has passed through the hot rolling mill 1 for fewer times of reciprocating rolling. If it is alloy steel with high rolling times, it means that the alloy steel has passed through the hot rolling mill 1 for more times of reciprocating rolling. The water cooling method adopted by the PLC system for the alloy steel with low rolling times is to first fill the water tank 6 with cooling water, and then fill it up again when the cooling water in the water tank 6 drops to the preset liquid level. This method can not only meet the water cooling demand of the alloy steel but also maintain the benefit of low energy consumption. The water cooling method adopted by the PLC system for the alloy steel with high rolling times is to first fill the water tank 6 with cooling water, and then the PLC system opens the second intelligent valve 16 and the second pump, and uses the second pump to draw out a part of the cooling water in the water tank 6 through the first The second water injection port 8 is transported to the fourth water cooling pipe 14, and then transported to the collecting pipe 12 through the fourth water cooling pipe 14, and finally refluxed to the water tank 9 through the second water cooling pipe 11. Then, the PLC system opens the first intelligent valve 15 and the first pump to transport the cooling water in the water tank 9 to the water tank 6, completing the cooling water circulation between the water tank 6 and the water tank 9, so that the cooling water temperature in the water tank 6 is always kept at a low temperature, thereby ensuring the high quality of water cooling of the alloy steel. Due to the high number of rolling times, the alloy steel has a large number of reciprocating times and a large number of cooling times required. The heat energy generated in the single block area of ​​the alloy steel is high, and the cooling water temperature in the water tank 6 above it rises quickly. It is necessary to maintain the cooling water temperature in the water tank 6 at a relatively low temperature to ensure that the water cooling of the single block area of ​​the alloy steel is effective, thereby effectively eliminating the unfavorable microstructures such as network carbides on the surface of the alloy steel. The water spray assembly 17 includes a groove 18 arranged at the bottom of the water tank 6, a plurality of spray pipes 19 are arranged at the bottom of the groove 18, and a support rod 20 is fixedly installed between adjacent spray pipes 19. The support rod 20 improves the stability of the spray pipe 19, so that the spray pipe 19 has higher stability when spraying cooling water. The spray pipe 19 is connected to the water tank 6 pipeline and a micro pump is arranged at the connection between the two. The micro pump is controlled by the PLC system, and then the cooling water in the water tank 6 can be discharged; The water spray assembly 17 further includes a telescopic plate 21 arranged on both sides of a plurality of spray pipes 19. The interior of the telescopic plate 21 is a hollow structure. The top of the telescopic plate 21 is connected to the water tank 6 pipeline. The water in the water tank 6 is transported into the telescopic plate 21. A plurality of intelligent mist nozzles 22 are evenly arranged on the side wall of the telescopic plate 21 from top to bottom. When the alloy steel output by the hot rolling mill 1 needs to be water-cooled, the PLC system drives the telescopic plate 21 to descend, and then the intelligent mist nozzle 22 is started to atomize the cooling water in the telescopic plate 21, so that the temperature of the output end area of ​​the hot rolling mill 1 is greatly reduced, thereby improving the efficiency of cooling the alloy steel with cooling water. Among them, a liquid level sensing structure is set in the water tank 6 to transmit data to the PLC system in real time. The liquid level sensing structure is a prior art structure; The air cooling mechanism 5 is divided into a top air cooling component 23 arranged in the input end area of ​​the hot rolling mill 1 and a transverse stepping transmission air cooling component 24 arranged in the output end area of ​​the hot rolling mill 1; The top air cooling component 23 includes a first fan casing 25 arranged on the top of the water tank 9, the top pipeline of the first fan casing 25 is connected to the first air duct 26, the first air duct 26 is connected to the wind bin 27 slidably arranged on the sliding track 3, and pulley assemblies are also arranged at the four corners of the bottom of the wind bin 27, and the first air outlet 28 is arranged at the bottom of the wind bin 27. A first fan is arranged in the first fan casing 25, and the first fan is driven by the PLC system. The blowing direction of the first fan is upward, and the airflow blown by the first fan enters the wind bin 27 through the first air duct 26, and then blows downward to the alloy steel at the input end of the hot rolling mill 1 below through the first air outlet 28 of the wind bin 27, and then the alloy steel is air-cooled. Since the water tank 9 always maintains a low temperature, the temperature of the airflow transported upward by the first fan casing 25 is relatively low, the air-cooling efficiency of the alloy steel is relatively high, and the energy consumption generated by improving the air-cooling efficiency can be ignored; A first side wind plate 29 is arranged at the input end area of ​​the hot rolling mill 1 and on one side close to the water tank 9. The first side wind plate 29 is provided with a second air port 33 in the direction of the roller matched with the hot rolling mill 1. The second air port 33 is aligned with the roller bearing the alloy steel. Two second air ducts 30 are arranged on the side wall of the first side wind plate 29. The two second air ducts 30 are respectively connected to a first water storage tank 31. A second fan housing 32 is arranged at the connection between each first water storage tank 31 and the second air duct 30. A second fan is arranged in each second fan housing 32. A connecting pipe is provided between a water storage tank 31 and the water tank 9, so that the cooling water in the water tank 9 can directly enter the first water storage tank 31, and then drive the second fan through the PLC system. The blowing direction of the second fan is upward, and the airflow blown by the second fan enters the first side wind plate 29 through the second air duct 30, and finally the roller and the alloy steel carried above it are air-cooled through the second air outlet 33. This air-cooling process is used as an auxiliary method to reduce the temperature of the alloy steel by reducing the temperature of the bearing, and can also undertake a partial cleaning function of the bearing; The lateral step-by-step transmission air-cooling component 24 includes a convection bin 34 connected to the water tank 9. A connecting pipe is also arranged between the convection bin 34 and the water tank 9 so that the cooling water in the water tank 9 can directly enter the convection bin 34. A first convection tube 35 and a second convection tube 36 are arranged on the side wall of the convection bin 34. The first convection tube 35 and the second convection tube 36 are connected to the same second water storage bin 37. A plurality of third fan housings 38 are arranged on the top of the second water storage bin 37. A third fan is arranged in each third fan housing 38. The third fan is connected to a third air duct 39. The third air duct 39 is connected to a second side wind plate 40 arranged on both sides of the output end area of ​​the hot rolling mill 1. A third air outlet 41 is arranged on the side wall of the second side wind plate 40 facing the hot rolling mill 1. The side air plate 40 is higher than the first side air plate 29, and its function is to air cool the alloy steel. The third fan is driven by the PLC system, and the airflow blown by the third fan enters the second side air plate 40 through the third air duct 39, and finally the alloy steel is air-cooled through the third air outlet 41. Since the temperature of the output end area of ​​the hot rolling mill 1 is high, and the alloy steel in the output end area of ​​the hot rolling mill 1 needs to be cooled with high intensity, a third pump is provided at the connection between the first convection pipe 35 and the convection bin 34, so that the cooling water in the convection bin 34 and the cooling water in the second water storage bin 37 are continuously circulated, and then the temperature of the airflow blown by the third fan is always kept at a low temperature, and the alloy steel is air-cooled at both sides at the same time, and the cooling effect is better; The arrangement of the water cooling system 4 and the air cooling mechanism 5 realizes the automated process of water cooling and air cooling, eliminates the network carbides in the alloy steel microstructure, and obtains a good microstructure by slow cooling at low temperature, thereby preparing for the subsequent acquisition of a good heat treatment microstructure and properties such as hardness.

[0018] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0019] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An alloy steel hot rolling mill, comprising a hot rolling mill (1), characterized in that: A metal frame (2) is provided on the hot rolling line of the hot rolling mill (1); a sliding track (3) is provided on the top of the metal frame (2); a water cooling system (4) and a transversely fixed air cooling mechanism (5) are slidably connected on the sliding track (3); a total driving power supply box (42) is provided on the sliding track (3); the total driving power supply box (42) is electrically connected to the water cooling system (4) and the air cooling mechanism (5); The water cooling system (4) comprises a water tank (6) slidably connected to the sliding track (3), a first water injection port (7) and a second water injection port (8) are arranged on a side wall of one side of the water tank (6), a second pump is arranged at a portion of the second water injection port (8) located inside the water tank (6), and a water tank (9) is arranged on one side of the hot rolling mill (1).

2. The alloy steel hot rolling mill according to claim 1, characterized in that: A first water cooling pipe (10) and a second water cooling pipe (11) are arranged at the top of the water tank (9) and in the same row as the output end of the hot rolling mill (1); a first pump is arranged at the part of the first water cooling pipe (10) located in the water tank (9); the first water cooling pipe (10) and the second water cooling pipe (11) extend upward and are connected to a collecting pipe (12) through a centralized pipe; the collecting pipe (12) extends upward and is symmetrically connected to a third water cooling pipe (13) and a fourth water cooling pipe (14); the third water cooling pipe (13) is plug-connected to the first water injection port (7); the fourth water cooling pipe (14) is plug-connected to the second water injection port (8); a first intelligent valve (15) is arranged on the third water cooling pipe (13); and a second intelligent valve (16) is arranged on the fourth water cooling pipe (14).

3. The alloy steel hot rolling mill according to claim 2, characterized in that: A water spray assembly (17) is arranged in the middle area of ​​the bottom of the water tank (6), and the water spray assembly (17) comprises a groove (18) arranged at the bottom of the water tank (6), a plurality of spray pipes (19) are arranged at the bottom of the groove (18), and support rods (20) are fixedly installed between adjacent spray pipes (19).

4. The alloy steel hot rolling mill according to claim 3, characterized in that: The water spray assembly (17) further comprises a telescopic plate (21) arranged on both sides of the plurality of spray pipes (19), the top of the telescopic plate (21) being connected to a pipe of the water tank (6), and a plurality of intelligent mist nozzles (22) being evenly arranged on the side wall of the telescopic plate (21) from top to bottom.

5. The alloy steel hot rolling mill according to claim 4, characterized in that: The air cooling mechanism (5) is divided into a top-mounted air cooling component (23) arranged in the input end area of ​​the hot rolling mill (1) and a transverse stepping transmission air cooling component (24) arranged in the output end area of ​​the hot rolling mill (1), the top-mounted air cooling component (23) comprising a first fan casing (25) arranged on the top of the water tank (9), the top pipeline of the first fan casing (25) being connected to a first air duct (26), the first air duct (26) being connected to an air bin (27) slidably arranged on the sliding track (3), a first air outlet (28) being arranged at the bottom of the air bin (27), and a first fan being arranged in the first fan casing (25).

6. The alloy steel hot rolling mill according to claim 5, characterized in that: A first side wind plate (29) is arranged at the input end area of ​​the hot rolling mill (1) and at a side close to the water tank (9); a second air outlet (33) is arranged on the first side wind plate (29) in the direction of a roller matched with the hot rolling mill (1); two second air ducts (30) are arranged on the side wall of the first side wind plate (29); the two second air ducts (30) are respectively connected to a first water storage tank (31); a second fan casing (32) is arranged at the connection between each first water storage tank (31) and the second air duct (30); and a second fan is arranged in each second fan casing (32).

7. The alloy steel hot rolling mill according to claim 6, characterized in that: The transverse step-transfer air cooling component (24) comprises a convection chamber (34) connected to the water tank (9), a first convection tube (35) and a second convection tube (36) are arranged on the side wall of the convection chamber (34), the first convection tube (35) and the second convection tube (36) are connected to the same second water storage chamber (37), a plurality of third fan casings (38) are arranged on the top of the second water storage chamber (37), and a third fan is arranged in each of the third fan casings (38).

8. The alloy steel hot rolling mill according to claim 7, characterized in that: The third fan is connected to a third air duct (39), the third air duct (39) is connected to second side air plates (40) arranged on both sides of the output end area of ​​the hot rolling mill (1), and the second side air plates (40) are provided with third air outlets (41) on the side walls facing the hot rolling mill (1).

9. A cooling method for an alloy steel hot rolling mill, applicable to an alloy steel hot rolling mill as claimed in any one of claims 1 to 8, characterized in that: The steps include: S1, the water tank (6) moves to a preset position; S2, the collecting pipe (12) is extended to a preset height, the third water cooling pipe (13) is connected to the first water injection port (7), and the fourth water cooling pipe (14) is connected to the second water injection port (8); S3, the cooling water in the water tank (9) is transported to the first water-cooling pipe (10), enters the collecting pipe (12) through the first water-cooling pipe (10), enters the third water-cooling pipe (13) through the collecting pipe (12), and finally is transported into the water tank (6) through the first water filling port (7) until the water tank (6) is filled.

10. The method for cooling an alloy steel hot rolling mill according to claim 9, characterized in that: The PLC system pre-enters the rolling times of the alloy steel and divides it into alloy steel with low rolling times and alloy steel with high rolling times; The water cooling method adopted by the PLC system for the alloy steel with a low rolling number is to first fill the water tank (6) with cooling water, and then fill it up again when the cooling water in the water tank (6) drops to a preset liquid level; The water cooling method adopted by the PLC system for the alloy steel with a high rolling number is as follows: first, the water tank (6) is filled with cooling water, and then the PLC system opens the second intelligent valve (16) and the second pump, and a portion of the cooling water in the water tank (6) is pumped out by the second pump and transported to the fourth water cooling pipe (14) through the second water inlet (8), and then transported to the collecting pipe (12) through the fourth water cooling pipe (14), and finally returned to the water tank (9) through the second water cooling pipe (11). Then, the PLC system opens the first intelligent valve (15) and the first pump, and transports the cooling water in the water tank (9) to the water tank (6), thereby completing the cooling water circulation between the water tank (6) and the water tank (9).

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