Temperature control water cooling device and method for high-quality steel bar

Abstract

The present application relates to the temperature control water cooling device and method of high-quality steel bar, belongs to the technical field of steel rolling, the temperature control water cooling device includes the water cooling tank, the upper portion of water cooling tank is equipped with the chain device to push material to the rolling piece on the rapid conveying device before the temperature control water cooling device is pushed into the water cooling tank according to certain rhythm, and the rolling piece in the water cooling tank is pushed forward;The end of water cooling tank is equipped with rolling piece collection frame, the top of rolling piece collection frame has opening, and the height of the side of opening near water cooling tank is lower than the rotating center of chain device to push material to accept the rolling piece pushed out by chain device to push material;The upper portion of water cooling tank is equipped with water / solution spraying system to spray and cool the rolling piece in water cooling tank.The device can realize three cooling modes of water immersion cooling, spraying cooling and natural cooling, and can meet the cooling demand of high-quality steel bar.

Description

Technical Field

[0001] This invention belongs to the field of steel rolling technology and relates to a temperature-controlled water-cooling device and method for special steel bars. Background Technology

[0002] In the metallurgical steel rolling sector, special steel refers to a general term for high-quality carbon steel and special steel. Special steel is divided into ordinary steel and special steel. The continued rapid development of the manufacturing industry, especially in machinery, automotive, electromechanical, and shipbuilding sectors, has created a strong demand for special steel, directly supporting the special steel market.

[0003] Traditional bar rolling rapid cooling to achieve residual heat treatment involves cooling the steel bars with a final rolling temperature of 900-1100℃ directly through a water cooler for surface quenching, rapidly reducing the surface temperature to 200-300℃. Then, residual heat is transferred from the core of the rolled piece to the air, raising the steel temperature to a self-tempering temperature of 550-650℃. This process aims to improve the strength, plasticity, and toughness of the steel, resulting in excellent overall performance.

[0004] Traditional controlled cooling of bar stock is mainly used in the production of rebar. The coolers are generally long, with a single unit approaching 2000m or longer, and are usually arranged continuously. The temperature recovery time after cooling is short, and the surface of the bar stock is easily chilled, resulting in the formation of a martensite layer. Martensite is hard and brittle, and while it increases strength, it decreases toughness.

[0005] For the production of high-quality special steel round bars, it is necessary to avoid the formation of surface quenched martensite and reduce the temperature difference between the surface and core of the bar. Therefore, controlling the cooling intensity and using intermittent cooling and temperature recovery (cooling-recovery-recooling-recovery) methods are quite effective for the production of high-quality special steel round bars. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a temperature-controlled water-cooling device and method for special steel bars to meet the cooling requirements of special steel bars.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A temperature-controlled water-cooling device for special steel bars includes a water-cooling tank. Above the water-cooling tank is a feeding chain device to rhythmically feed rolled pieces from a fast conveyor in front of the temperature-controlled water-cooling device into the water-cooling tank. The feeding chain device includes a chain drive mechanism with several feeding rods spaced apart on the chain. The distance between the lower end of the feeding rod closest to the water-cooling tank and the inner bottom of the water-cooling tank is less than the radius of the rolled piece, thus propelling the rolled piece forward. At the end of the water-cooling tank is a rolled piece collection frame with an opening at the top. The opening is positioned below the rotation center of the feeding chain device on the side closest to the water-cooling tank, to receive rolled pieces fed by the feeding chain device. Above the water-cooling tank is a water / solution spray system to spray and cool the rolled pieces within the water-cooling tank.

[0009] Optionally, the opening of the rolled piece collection frame is arranged at an angle, with the side closer to the water cooling tank being lower.

[0010] Optionally, the lower end of the feeding rod is provided with a roller that contacts the bottom of the water-cooling tank.

[0011] Optionally, the drive unit of the feeding chain device has a built-in speed encoder.

[0012] Optionally, the water-cooled tank includes a tank base, a water tank mounted on the tank base, and an inlet pipe and a return pipe connected to the water tank. The inlet pipe and the return pipe are respectively located at the front and rear ends of the water tank, and both the inlet pipe and the return pipe are equipped with valves.

[0013] Optionally, the sink is a detachable and modular sink.

[0014] Optionally, the bottom of the water-cooled tank is equipped with a removable abrasion plate.

[0015] A method for temperature-controlled water cooling of special steel bars, providing the temperature-controlled water cooling device as described above, includes the following steps:

[0016] S1: The high-temperature rolled piece is quickly removed from the rolling line by a rapid conveying device in front of the temperature-controlled water cooling device;

[0017] S2: Match the speed of the feeding chain device with the speed of the fast conveyor device, and feed the high-temperature rolled piece from the fast conveyor device into the water cooling tank in a rhythmic manner, and detect the temperature of the high-temperature rolled piece by the temperature detection element set above the chain drive mechanism.

[0018] S3: Based on the obtained temperature of the high-temperature rolled piece, and according to the temperature control and cooling method and cooling parameters set by the process for rolling pieces of different materials and specifications, control the cooling time or spraying time of the high-temperature rolled piece in the water cooling tank to obtain the low-temperature rolled piece.

[0019] S4: The feeding chain device pushes the low-temperature rolled piece out of the water-cooling tank, and then the low-temperature rolled piece rolls into the rolled piece collection frame.

[0020] Includes the following cooling modes:

[0021] Immersion cooling mode: The feeding chain device feeds the high-temperature rolled pieces conveyed by the fast conveyor into the water cooling tank filled with water / solution according to the process control cooling time and rhythm, and immerses them in water to obtain low-temperature rolled pieces with accurate cooling temperature control. Then, the feeding chain device pushes the low-temperature rolled pieces out of the water cooling tank and rolls into the rolled piece collection frame.

[0022] Spray cooling mode: The feeding chain device will transport the high-temperature rolled piece from the fast conveyor device through the water cooling tank according to the process control cooling time and rhythm. During the passage through the water cooling tank, the feeding chain device controls the running speed of the rolled piece, and the water / solution spray system located above the water cooling tank will spray and cool it to obtain a low-temperature rolled piece with an accurately controlled cooling temperature. Then, the feeding chain device will push the low-temperature rolled piece out of the water cooling tank and roll it into the rolled piece collection frame.

[0023] Natural cooling mode: The feeding chain device will transport the high-temperature rolled pieces from the fast conveyor device through the water cooling tank with less water / solution according to the process control cooling time and rhythm. The feeding chain device will push the rolled pieces that need to be slowly cooled out of the water cooling tank. The low-temperature rolled pieces will roll into the rolled piece collection frame, be bundled and transferred to the workshop slow cooling pit.

[0024] Optionally, the water / solution used to cool the rolled piece is prepared according to pre-defined parameters, and the water / solution temperature is pre-controlled.

[0025] Optionally, the drive unit adjusts its speed via a built-in encoder, matching the maximum speed of the conveying rolled piece in the high-speed conveying device before the temperature-controlled water-cooling device, so that the push bar can push the high-temperature rolled piece into the water-cooling tank and push the low-temperature rolled piece out of the water-cooling tank.

[0026] Optionally, the replacement of water / solution and the control of liquid level in the water-cooled tank are controlled by a valve installed on the return water pipe.

[0027] The beneficial effects of this invention are as follows:

[0028] This temperature-controlled water cooling device can achieve three cooling modes: immersion cooling, spray cooling, and natural cooling. It can meet the cooling requirements of special steel bars, effectively avoid the formation of surface quenched martensite, achieve microstructure control, and ensure good temperature uniformity between the surface and core, with a temperature difference between the surface and core of ≤50℃. This method can be used in the development and production of special steel products such as bearing steel, non-quenched and tempered steel, and spring steel, solving the problem of deep quenched layers on the surface in existing controlled rolling and controlled cooling processes.

[0029] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0031] Figure 1 This is a schematic diagram showing the cross-section of the temperature-controlled water-cooling device and the running direction of the rolled piece according to the present invention;

[0032] Figure 2 This is a side view of the drive end of the temperature-controlled water-cooling device of the present invention;

[0033] Figure 3 This is a top view of the temperature-controlled water-cooling device and a schematic diagram of the spray system of the present invention.

[0034] Reference numerals: 1. Material feeding chain device; 2. Rapid conveying device; 3. Water cooling tank; 4. Rolled piece collection frame; 5. High-temperature rolled piece; 6. Water / solution spraying system; 7. Drive device; 8. Hollow sleeve coupling; 9. Drive shaft; 10. Drive sprocket; 11. Bearing seat; 12. Material feeding rod; 13. Coupling; 14. Chain tensioning device; 15. Drive device mounting base; 16. Drive shaft mounting bracket; 17. Tensioning device mounting bracket; 18. Upper crossbeam of mounting bracket; 19. Upper crossbeam gap beam; 20. Crossbeam mounting base; 21. Chain track; 22. Water tank base; 23. Water tank; 24. Water tank support crossbeam; 25. Water tank wear-resistant plate; 26. Water tank seal; 27. Inlet pipe; 28. Return pipe; 29. ​​Valve; 30. Valve seat; 31. Water / solution main pipe; 32. Water / solution branch pipe. Detailed Implementation

[0035] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0036] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0037] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0038] Please see Figures 1-3 The temperature-controlled water cooling device for special steel bars includes a water cooling tank 3. A feeding chain device 1 is installed above the water cooling tank 3 to feed the rolled steel pieces from the rapid conveying device 2 located in front of the temperature-controlled water cooling device into the water cooling tank 3 at a certain rhythm. The feeding chain device 1 includes a chain drive mechanism. Several feeding rods are spaced apart on the chain of the chain drive mechanism. The distance between the lower end of the feeding rod closest to the water cooling tank 3 and the inner bottom of the water cooling tank 3 is less than the radius of the rolled steel piece, so as to advance the rolled steel piece located in the water cooling tank 3 forward. The lower end of 12 may not contact the inner bottom of the water cooling tank 3, or it may contact the inner bottom of the water cooling tank 3 through rollers; the end of the water cooling tank 3 is provided with a rolled piece collection frame 4, the top of the rolled piece collection frame 4 has an opening, preferably the opening is arranged at an angle, and the height of the side of the opening near the water cooling tank 3 is lower than the rotation center of the feeding chain device 1, so as to receive the rolled piece fed out by the feeding chain device 1; a water / solution spraying system is provided above the water cooling tank 3 to spray and cool the rolled piece located in the water cooling tank 3.

[0039] Specifically:

[0040] The feeding chain device 1 mainly includes a drive unit 7, a hollow sleeve coupling 8, a transmission shaft 9, a drive sprocket 10, a bearing seat 11, a chain, a feeding rod 12, a coupling 13, a chain tensioning device 14, a drive unit mounting base 15, a transmission shaft mounting bracket 16, a tensioning device mounting bracket 17, an upper crossbeam 18, an upper crossbeam gap beam 19, a crossbeam mounting base 20, and a chain track 21. The feeding rod 12 is connected to the chain at one end and has a roller at the other end. The drive unit 7 has a built-in speed encoder to match the maximum speed of the conveying unit 2 before the temperature-controlled water-cooling device, controlling the movement speed of the feeding rod 12 to smoothly feed the high-temperature rolled piece 5 into the water-cooling tank 3, and to smoothly push the low-temperature rolled piece 5 out of the water-cooling tank 3 according to the cooling control process parameters.

[0041] The water-cooled tank 3 mainly includes a tank base 22, a detachable and modular water tank 23, a tank support beam 24, a detachable water tank wear-resistant plate 25, a tank seal 26, an inlet pipe 27, a return pipe 28, and a valve 29. The water-cooled tank 3 is an upward-opening container with excellent sealing and structural integrity. The replacement of the internal water / solution and the control of the liquid level can be achieved through the valve 29 installed on the return pipe 28. Furthermore, the replacement frequency and temperature of the water / solution can be effectively controlled to accurately control the mandrel temperature, surface temperature, and surface hardness of the low-temperature rolled product 5. The feed rod 12, connected to the chain, works in conjunction with the detachable water tank wear-resistant plate 25 to roll the special steel bar forward.

[0042] The water / solution spraying system 6 mainly includes a valve platform 30, a water / solution main pipe 31, a water / solution branch pipe 32, water / solution nozzles, a return water pipe 28, and a valve 29. The spraying flow rate, pressure, and spraying duration of the water / solution in the water / solution spraying system 6 are controlled by the valve platform 30 according to the process design parameters, so as to accurately control the mandrel temperature, surface temperature, and surface hardness of the low-temperature rolled workpiece 5.

[0043] The rapid conveying device 2 can be replaced by other structural workpiece conveying mechanisms or workpiece conveying devices, and the workpiece collection frame 4 can be replaced by other structural workpiece collection mechanisms or workpiece collection devices.

[0044] This invention also provides a method for temperature-controlled water cooling of special steel bars, comprising the following steps:

[0045] Step 1: The high-temperature rolled piece 5 is quickly removed from the rolling line by the rapid conveying device 2 in front of the temperature-controlled water cooling device;

[0046] Step 2: The speed of the feeding chain device 1 is matched with the speed of the fast conveyor device 2, and the high-temperature rolled piece 5 is fed from the fast conveyor device 2 into the water cooling tank 3 in a rhythmic manner. The temperature of the high-temperature rolled piece 5 is detected by the temperature detection element set above the chain.

[0047] Step 3: Based on the obtained temperature of the high-temperature rolled piece 5, and according to the temperature control and cooling methods and parameters set by the process for rolling pieces of different materials and specifications, control the cooling time or spraying time of the high-temperature rolled piece 5 in the water cooling tank 3 to obtain a low-temperature rolled piece. The water / solution used to cool the rolled piece can be prepared according to the preset parameters, and the water / solution temperature can be controlled in advance. The replacement of water / solution and the control of liquid level in the water cooling tank 3 can be controlled by the valve 29 installed on the return water pipe 28.

[0048] Step 4: The feeding chain device 1 pushes the high-temperature rolled piece 5, which has been cooled and controlled according to the process specifications, out of the water cooling tank 3 and rolls it into the rolled piece collection frame 4.

[0049] Includes the following cooling modes:

[0050] Immersion cooling mode: The feeding chain device 1 feeds the high-temperature rolled piece 5, which is conveyed by the fast conveyor device 2 in front of the temperature-controlled water cooling device, into the water cooling tank 3 filled with water / solution according to the process control cooling time and rhythm, and immerses it in water to obtain a low-temperature rolled piece with accurate cooling temperature control. The feeding chain device 1 pushes the low-temperature rolled piece with accurate cooling temperature control out of the water cooling tank 3, and the low-temperature rolled piece rolls into the rolled piece collection frame 4.

[0051] Spray cooling mode: The feeding chain device 1 transports the high-temperature rolled piece 5, which is conveyed by the fast conveyor device 2 in front of the temperature-controlled water cooling device, through the water cooling tank 3 according to the cooling time and rhythm controlled by the process. The water cooling tank 3 is equipped with a water / solution spraying system 6. The feeding chain device 1 controls the running speed of the rolled piece, and the water / solution spraying system 6 controls the spraying time and flow rate of the water / solution. The feeding chain device 1 pushes the low-temperature rolled piece with the accurately controlled cooling temperature out of the water cooling tank 3 and rolls it into the rolled piece collection frame 4.

[0052] Natural cooling mode: The high-temperature rolled piece 5, which is conveyed by the fast conveyor device 2 in front of the temperature-controlled water cooling device, passes through the water cooling tank 3 with less water / solution according to the cooling time and rhythm controlled by the process. The rolled piece that needs to be slowly cooled is pushed out of the water cooling tank 3 by the rolling chain device 1, rolled into the rolled piece collection frame 4, bundled and transferred into the workshop slow cooling pit.

[0053] In the natural cooling mode, the high-temperature rolled piece 5 is fed into the water-cooling tank 3 with a small amount of water / solution by the feeding chain device 1. The small amount of water / solution in the water-cooling tank 3 ensures that the water-cooling tank 3 itself is not affected by the temperature of the high-temperature rolled piece 5, ensuring that the structure does not deform and extending the service life. The removable wear-resistant plate 25 of the water tank can be easily replaced, saving the cost of use.

[0054] Existing bar cooling control devices employ segmented control, which lengthens the rolling mill and imposes greater demands on workshop layout. Due to the increased rolling mill length, existing bar cooling control technologies require more intermediate components such as roller conveyors and pinch rolls. This necessitates more cooling facilities, leading to higher energy consumption, more complex control processes, and a greater number of dispersed control modules, resulting in significantly more potential risks. Compared to existing bar cooling control devices, this invention offers significant advantages: a more compact structure, lower energy consumption, and integrated control for more precise and controllable cooling temperature. Furthermore, the reduction in control modules means fewer potential risks and easier overall adjustment and handling, while also requiring less stringent workshop layout requirements.

[0055] This invention, while satisfying the mechanical properties of bar stock, solves the problem of deep quenching layers appearing on the surface in traditional controlled rolling and cooling processes. It effectively avoids the formation of surface quenched martensite, achieves microstructure control, and ensures good temperature uniformity between the surface and core, with a temperature difference of ≤50℃. This method can be used in the development and production of high-quality special steel products such as bearing steel, non-quenched and tempered steel, and spring steel.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for temperature-controlled water cooling of special steel bars, characterized in that: A temperature-controlled water cooling device is provided, which includes a water cooling tank (3). A feeding chain device (1) is provided above the water cooling tank (3) to feed the rolled piece on the fast conveying device (2) in front of the temperature-controlled water cooling device into the water cooling tank (3) at a certain rhythm. The feeding chain device (1) includes a chain drive mechanism. Several feeding rods (12) are provided at intervals on the chain of the chain drive mechanism. The distance between the lower end of the feeding rod near the water cooling tank (3) and the inner bottom of the water cooling tank (3) is less than that of the rolled piece. The radius is used to advance the rolled piece located in the water cooling tank (3); the end of the water cooling tank (3) is provided with a rolled piece collection frame (4), the top of the rolled piece collection frame (4) has an opening, and the side of the opening near the water cooling tank (3) is lower than the rotation center of the feeding chain device (1) to receive the rolled piece fed out by the feeding chain device (1); a temperature-controlled water / solution spray system (6) is provided above the water cooling tank (3) to spray and cool the rolled piece located in the water cooling tank (3); The temperature-controlled water cooling method includes the following steps: S1: The high-temperature rolled piece (5) is quickly removed from the rolling line by the rapid conveying device (2) in front of the temperature-controlled water cooling device; S2: Match the speed of the feeding chain device (1) with the speed of the fast conveying device (2), and feed the high-temperature rolled piece (5) from the fast conveying device (2) into the water cooling tank (3) in a rhythmic manner, and detect the temperature of the high-temperature rolled piece (5) by the temperature detection element set above the chain drive mechanism. S3: Based on the temperature of the high-temperature rolled piece (5) obtained, and according to the temperature control and cooling method and cooling parameters set by the process for different materials and specifications of rolled pieces, control the cooling time or spraying time of the high-temperature rolled piece (5) in the water cooling tank (3) to obtain the low-temperature rolled piece; S4: The feeding chain device (1) pushes the low-temperature rolled piece out of the water cooling tank (3), and the low-temperature rolled piece rolls into the rolled piece collection frame (4).

2. The method for temperature-controlled water cooling of special steel bars according to claim 1, characterized in that: The opening of the rolled piece collection frame (4) is arranged at an angle, and the side closer to the water cooling tank (3) is lower.

3. The method for temperature-controlled water cooling of special steel bars according to claim 1, characterized in that: The lower end of the feeding rod (12) is provided with a roller that contacts the bottom of the water-cooling tank (3).

4. The method for temperature-controlled water cooling of special steel bars according to claim 1, characterized in that: The drive unit (7) of the feeding chain device (1) has a built-in speed encoder.

5. The method for temperature-controlled water cooling of special steel bars according to claim 1, characterized in that: The water-cooled tank (3) includes a tank base (22), a tank (23) set on the tank base, an inlet pipe (27) and a return pipe (28) connected to the tank (23). The inlet pipe (27) and the return pipe (28) are respectively set at the front and rear ends of the tank (23), and both the inlet pipe (27) and the return pipe (28) are equipped with valves.

6. The method for temperature-controlled water cooling of special steel bars according to claim 5, characterized in that: The sink (23) is a detachable and modular sink.

7. The method for temperature-controlled water cooling of special steel bars according to claim 5, characterized in that: The bottom of the water-cooled tank (3) is provided with a removable water tank wear plate (25).

8. The method for temperature-controlled water cooling of special steel bars according to claim 1, characterized in that, Includes the following cooling modes: Immersion cooling mode: The feeding chain device (1) feeds the high-temperature rolled piece (5) conveyed by the fast conveying device (2) into the water cooling tank (3) filled with water / solution according to the process control cooling time and rhythm, and immerses it in water to obtain a low-temperature rolled piece with accurate cooling temperature control. Then the feeding chain device (1) pushes the low-temperature rolled piece out of the water cooling tank (3) and the low-temperature rolled piece rolls into the rolled piece collection frame (4). Spray cooling mode: The feeding chain device (1) transports the high-temperature rolled piece (5) from the fast conveying device (2) through the water cooling tank (3) according to the process control cooling time and rhythm. During the passage through the water cooling tank, the feeding chain device (1) controls the running speed of the rolled piece, and the water / solution spray system (6) located above the water cooling tank (3) sprays and cools it to obtain a low-temperature rolled piece with an accurate cooling temperature. Then, the feeding chain device (1) pushes the low-temperature rolled piece out of the water cooling tank (3), and the low-temperature rolled piece rolls into the rolled piece collection frame (4). Natural cooling mode: The feeding chain device (1) will transport the high-temperature rolled piece (5) from the fast conveying device (2) through the water cooling tank (3) with less water / solution according to the process control cooling time and rhythm. The feeding chain device (1) will push the rolled piece that needs to be slowly cooled out of the water cooling tank (3), and the low-temperature rolled piece will roll into the rolled piece collection frame (4).

9. The method for temperature-controlled water cooling of special steel bars according to claim 1, characterized in that: The water / solution used to cool the rolled pieces is prepared according to pre-defined parameters, and the temperature of the water / solution is pre-controlled.

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