Cooling device for wire and bar roughing mill frame roller

Abstract

The utility model discloses a cooling device for a roll of a wire and bar roughing mill frame, which comprises spray nozzles and water spray nozzles arranged on a fixed cross beam, the spray nozzles are positioned on the upper row, and the water spray nozzles are positioned on the lower row; the water supply device comprises a constant-temperature water tank, two water outlets are communicated with a first branch pipe and a second branch pipe through a first header pipe and a second header pipe respectively, the tail ends of the spray nozzles and the water spray nozzles are connected with the first branch pipe and the second branch pipe through water distribution pipes respectively, and high-pressure water pumps are arranged on the first header pipe and the second header pipe; the moving device comprises a lead screw which penetrates through threaded holes in the two ends of the fixed cross beam and is matched with the threaded holes, the top of the lead screw is connected with a driving shaft of the motor, the bottom of the lead screw is arranged on a moving frame, pulleys are arranged at the bottom of the moving frame, a hinge hole in which the lead screw can rotate is formed in the top of the moving frame, and a push-pull air cylinder is arranged on one side of the moving frame; a tempered sorbite structure is obtained, and the strength of a roller base body is improved.

Description

Technical Field

[0001] The utility model relates to a cooling device for a wire rod rough rolling stand roll, belonging to the technical field of roll manufacturing. Background Art

[0002] In recent years, with the development of high-speed and continuous rolling of wire rod rolling mills at home and abroad, and the continuous improvement of rolled material performance, especially the long length of rolled materials and the long heating time of rolls in recent years, steel mills have increasingly higher requirements for the applicability of rolls, requiring not only good wear resistance and high strength of rolls, but also better resistance to thermal cracking and toughness.

[0003] At present, the rough rolling mill for wire rods generally adopts pearlite ductile iron rolls, and the roll diameter is generally 300-1000mm. The heat treatment process of the rolls in the preparation process generally adopts normalizing + high temperature tempering treatment, and the cooling process usually adopts the following methods: Figure 3 The cooling device shown is used for cooling, including a tugboat 15 driven by a power mechanism to support and drive the roller to rotate. There are four tugboats 15 and they are distributed below the roller body. The roller 17 is placed on the tugboat 15. There are four tugboats 15, which are used to support the roller body and drive the roller 17 to rotate through the power mechanism. During cooling, a fan 16 is used for air cooling, and water is passed through a water pipe. Under the wind force of the fan 16, the water flowing out of the water pipe is sprayed in a mist form, and air cooling and atomized water cooling are performed, and finally the roller structure is pearlite. The rollers processed according to this heat treatment process have the following problems during use:

[0004] 1. The wear resistance of the roller is poor, the thermal cracks on the groove bottom are serious, and the single rolling volume is low. Due to the high rolling temperature and slow rolling speed of the rough rolling stand, the surface temperature of the roller body is high. The product of simple spray cooling is based on pearlite structure and has low strength. Under the continuous impact of the steel billet, thermal cracks are prone to occur on the bottom of the roller groove.

[0005] 2. Thermal cracks are prone to occur at the bottom of the groove during the rolling process of the roller, and the wear resistance is poor, and a good hole shape cannot be maintained, resulting in a failure to ensure a good material shape after rough rolling, affecting the subsequent rolling quality.

[0006] 3. The performance difference between the inner and outer working layers of the rollers is large. For the above heat-treated rollers, the hardness difference between the inner and outer working layers of 100mm can reach more than 5HSD, which leads to a significant decrease in the wear resistance of the rollers during the later use, a short rolling time on the mill, and affects the rolling efficiency. Utility Model Content

[0007] In order to solve the above technical problems, the utility model provides a cooling device for the rollers of a wire rod roughing mill frame, which adopts a spray nozzle and a water spray nozzle to realize water cooling + spray cooling, improves the quenching cooling intensity of the rollers, changes the organizational morphology, obtains the tempered bainite organization, improves the matrix strength of the rollers, and improves the comprehensive performance of the rollers by more than 1.5 times.

[0008] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0009] A cooling device for a roll of a wire rod roughing mill, comprising a tugboat driven by a power mechanism to support and drive the roll to rotate, wherein four tugboats are provided and distributed below the roll body; and further comprising a spray nozzle and a water spray nozzle provided on a fixed crossbeam and supplied with water by a water supply device and driven to move by a moving device, wherein the spray nozzle and the water spray nozzle are evenly spaced and arranged in a row, wherein the spray nozzle is located in an upper row and the water spray nozzle is located in a lower row;

[0010] The water supply device comprises a constant temperature water tank provided with two water outlets, and the two water outlets are connected to the first branch pipe and the second branch pipe through the first main pipe and the second main pipe respectively, the tail ends of the spray nozzle and the water spray nozzle are connected to the first branch pipe and the second branch pipe respectively through the water distribution pipe, and the first main pipe and the second main pipe are both provided with a high-pressure water pump;

[0011] The moving device includes a lead screw passing through threaded holes at both ends of the fixed crossbeam and matching with the threaded holes, the top of the lead screw is connected to the driving shaft of the motor, and the bottom is arranged on the moving frame, the bottom of the moving frame is provided with a pulley, and the lower part of the pulley is provided with a matching slide rail, and the top is provided with a hinge hole in which the lead screw can rotate, and one side of the moving frame is provided with a push-pull cylinder capable of pushing it to move;

[0012] The motor, the push-pull cylinder, the power mechanism and the high-pressure water pump are all electrically connected to the PLC controller.

[0013] A further improvement of the technical solution of the utility model is that the distance between each two adjacent spray nozzles and the distance between each two adjacent water spray nozzles are both 150 mm, and the distance between the upper row of spray nozzles and the lower row of water spray nozzles is 200 mm.

[0014] A further improvement of the technical solution of the utility model is that: the spray nozzle and the water spray nozzle and the water supply device and the moving device are provided with two sets, which are respectively located on both sides of the roller.

[0015] A further improvement of the technical solution of the utility model is that valves are provided on the first main pipe, the second main pipe, the first branch pipe and the second branch pipe in the water supply device, and a switch is provided on each spray nozzle and water spray nozzle, and the switches are electrically connected to the PLC controller.

[0016] A further improvement of the technical solution of the utility model is that the water inlet of the constant temperature water tank is connected to the factory water network, and a valve is provided on the water inlet pipe, a heating rod and a thermometer are provided inside the constant temperature water tank, and the heating rod, the thermometer and the valve on the water inlet pipe are all electrically connected to the PLC controller.

[0017] A further improvement of the technical solution of the utility model is that: each of the mobile racks is provided with two push-pull cylinders respectively located at two ends of the mobile rack, and the push-pull cylinders are fixed by fixed columns.

[0018] A further improvement of the technical solution of the utility model is that the mobile frame is configured as a structure with a trapezoidal cross section consisting of a top plate, a bottom plate and two side plates, and a vertical plate for fixing the motor is provided on the mobile frame.

[0019] A further improvement of the technical solution of the utility model is that two water baffles are arranged on the vertical plate, and a semicircular hole capable of accommodating the roll neck of the rolling mill is opened at the lower end of the water baffle.

[0020] A further improvement of the technical solution of the utility model is that: four pulleys are provided and distributed at four corner positions of the mobile frame.

[0021] A further improvement of the technical solution of the utility model is that a bearing is arranged in the hinge hole, and the inner ring of the bearing is fixed to the lead screw, and the outer ring is fixed to the inside of the hinge hole.

[0022] Due to the adoption of the above technical solution, the technical progress achieved by the utility model is:

[0023] The utility model adopts a spray nozzle and a water nozzle to realize water cooling + spray cooling, which can significantly improve the quenching cooling intensity and uniformity, improve the pearlite roller matrix structure, obtain the tempered sorbite structure, improve the roller matrix strength, and improve the roller body hardness uniformity to 1-2HSD. The single rolling amount of the roller is increased by 1.5 times, and the surface cracks on the bottom of the groove after leaving the machine are greatly improved.

[0024] The spray nozzle and the water spray nozzle of the utility model can move up and down and left and right, so the distance between the spray nozzle and the water spray nozzle and the roller can be adjusted conveniently, which is more conducive to the cooling of the roller. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a main structural schematic diagram of the utility model;

[0026] Figure 2 It is a schematic diagram of the structure of the utility model from top view;

[0027] Figure 3 It is a structural schematic diagram of the cooling device mentioned in the background technology of the utility model;

[0028] Figure 4 This is a metallographic structure diagram at 50 times the magnification in the embodiment of the utility model;

[0029] Figure 5 This is a metallographic structure diagram at 100 times the magnification in the embodiment of the utility model;

[0030] Figure 6 This is a metallographic structure diagram at 400 times magnification in the embodiment of the utility model;

[0031] Among them, 1. spray nozzle, 2. water nozzle, 3. water distribution pipe, 4. first branch pipe, 5. second branch pipe, 6. fixed beam, 7. screw, 8. motor, 9. moving frame, 10. pulley, 11. slide rail, 12. push-pull cylinder, 13. fixed column, 14. water baffle, 15. tugboat, 16. fan, 17. roller. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the embodiments:

[0033] like Figure 1 and 2 As shown, a cooling device for a wire rod roughing mill roll comprises a tug 15 driven to rotate by a power mechanism, wherein four tugs 15 are provided and distributed below the roll body to support and drive the roll to rotate. The power mechanism is electrically connected to a PLC controller, and the running time of the tug 15 is controlled by the PLC controller.

[0034] The cooling device also includes a spray nozzle 1 and a water spray nozzle 2 which are supplied with water by a water supply device and driven to move by a moving device. The spray nozzle 1 and the water spray nozzle 2 and their water supply device and moving device are provided in two sets, which are respectively located on both sides of the roller 17. The spray nozzle 1 and the water spray nozzle 2 are provided on the fixed crossbeam 6 and are evenly spaced in a row, with the spray nozzle 1 located in the upper row and the water spray nozzle 2 located in the lower row; the distance between each adjacent two spray nozzles 1 is 150 mm, the distance between each adjacent two water spray nozzles 2 is also 150 mm, and the distance between the upper row of spray nozzles 1 and the lower row of water spray nozzles 2 is 200 mm.

[0035] The water supply device includes a constant temperature water tank, and a heating rod and a thermometer are arranged inside the constant temperature water tank, and the heating rod and the thermometer are electrically connected to the PLC controller. The water temperature of the constant temperature water tank can be kept at 20°C by setting the PLC controller. When the water temperature is lower than 20°C, the heating rod will be controlled to open for heating, and the heating will stop when the water temperature reaches 20°C. The constant temperature water tank is provided with two water outlets and one water inlet; the water inlet is connected to the plant water pipe network, and a valve is arranged on the water inlet pipe; the valve on the water inlet pipe is also electrically connected to the PLC controller, and when the water temperature of the constant temperature water tank is higher than 20°C, the PLC controller controls the valve on the water inlet pipe to open and inject the groundwater with lower temperature. The two water outlets are connected to the first branch pipe 4 and the second branch pipe 5 through the first main pipe and the second main pipe respectively, and the tail ends of the spray nozzle 1 and the water spray nozzle 2 are connected to the first branch pipe 4 and the second branch pipe 5 through the water distribution pipe 3 respectively, and the first main pipe and the second main pipe are provided with a high-pressure water pump. The first main pipe, the second main pipe, the first branch pipe 4 and the second branch pipe 5 in the water supply device are all provided with valves, and each spray nozzle 1 and the water spray nozzle 2 are provided with switches, and the switches and the high-pressure water pump are electrically connected to the PLC controller. The spray time of the spray nozzle 1 and the water spray time of the water spray nozzle 2 are controlled by the PLC controller.

[0036] The moving device includes two lead screws 7, which pass through the threaded holes at both ends of the fixed beam 6 respectively and cooperate with the threaded holes. By rotating the lead screws 7, the fixed beam 6 moves up and down along the lead screws 7, thereby driving the spray nozzle 1 and the water spray nozzle 2 to move up and down. The power for the rotation of the lead screw 7 comes from the motor 8 at the top, and the driving shaft of the motor 8 is connected to the top of the lead screw 7; a moving frame 9 is provided at the bottom of the lead screw 7, and a vertical plate for fixing the motor 8 is provided on the moving frame 9.

[0037] The mobile frame 9 is configured as a structure with a trapezoidal cross section consisting of a top plate, a bottom plate and two side plates. The top plate is provided with a hinge hole in which the lead screw 7 can rotate. A bearing is provided in the hinge hole, and the inner ring of the bearing is fixed to the lead screw, and the outer ring is fixed to the inside of the hinge hole. A pulley 10 is provided at the bottom of the mobile frame 9. There are four pulleys, which are distributed at the four corner positions of the mobile frame 9. A matching slide rail 11 is provided below the pulley 10. A push-pull cylinder 12 capable of pushing the mobile frame 9 is provided on one side of the mobile frame 9. Each mobile frame 9 is provided with two push-pull cylinders 12 respectively located at the two ends of the mobile frame 9, and the push-pull cylinder 12 is fixed by a fixed column 13. The motor 8 and the push-pull cylinder 12 are electrically connected to the PLC controller. The PLC controller controls the motor 8 to rotate and drive the spray nozzle 1 and the water nozzle 2 to move up and down, controls the push-pull cylinder 12 to extend and retract to drive the spray nozzle 1 and the water nozzle 2 to move left and right, and adjusts the distance between the spray nozzle 1 and the water nozzle 2 and the outer side of the roller, which is generally 300-500mm.

[0038] A heat treatment process of a wire rod roughing mill roll during the preparation process is as follows, wherein the roll is cooled using the above-mentioned cooling device during cooling:

[0039] S1. Normalizing: Heat the roll to 820-860℃ and keep it for 5-10 hours to make the cross-section temperature of the entire roll uniform, and then cool the roll to room temperature in air;

[0040] S2, tempering: reheat the normalized roll to 680-720℃ and keep it at this temperature for 10-15 hours;

[0041] S3, cooling: the roller after heat preservation is cooled by a cooling device, first spraying + water spraying cooling for t1 time, and then spraying cooling for t2 time, so as to improve the quenching cooling intensity of the roller and obtain the tempered sorbite structure; and the water temperature of the spraying and water spraying is 20°C;

[0042] Among them, when the roller diameter in S3 is 300-500 mm, t1 is 5-10 min, and t1 is 10-15 min;

[0043] When the roller diameter is 500-800mm, t1 is 10-20min, t2 is 15-25min;

[0044] When the roller diameter is 800-1000mm, t1 is 20-30min, and t2 is 25-30min.

[0045] The first roll of a rough rolling mill for wire rods in a domestic steel plant was produced using the above cooling device and heat treatment process, and then a performance test was carried out. The test results are as follows:

[0046] 1. Hardness drop detection in the working layer

[0047] Distance from roller surface mm 5 15 20 25 30 35 40 45 Hardness HSD 55 55 54 54 54 54 53 53

[0048] 2. Metallographic structure detection Figure 4-5 As shown in the figure, it can be concluded that the structure is tempered troostite + carbide, the graphite area is 6.05%, the carbide area is 11.23%, and the matrix microhardness is 334.15Hm.

[0049] 3. Roller diameter tensile strength test: 675Mpa

[0050] The test product was tested on the first rough rolling stand, with a single rolling volume of 11,500 tons, twice that of the previous product. After the product was unloaded, the surface quality was good, no thermal cracks appeared, and the grinding volume was 12mm, a decrease of 45%. At present, the device has been put into normal use, and the products have been used in more than 30 steel mills at home and abroad, and all have achieved the above results.

Claims

1. A cooling device for a rolling mill roll of a wire rod roughing mill, comprising a tug (15) driven to rotate by a power mechanism for supporting and driving the rolling mill roll to rotate, wherein four tugs (15) are provided and distributed below the rolling mill roll body; characterized in that: It also comprises a spray nozzle (1) and a water spray nozzle (2) which are arranged on a fixed crossbeam (6) and are supplied with water by a water supply device and are moved by a moving device, wherein the spray nozzle (1) and the water spray nozzle (2) are evenly spaced and arranged in a row, with the spray nozzle (1) being located in the upper row and the water spray nozzle (2) being located in the lower row; The water supply device comprises a constant temperature water tank provided with two water outlets, and the two water outlets are respectively connected to a first branch pipe (4) and a second branch pipe (5) through a first main pipe and a second main pipe, the tail ends of the spray nozzle (1) and the water spray nozzle (2) are respectively connected to the first branch pipe (4) and the second branch pipe (5) through a water distribution pipe (3), and the first main pipe and the second main pipe are both provided with a high-pressure water pump; The moving device comprises a lead screw (7) passing through threaded holes at both ends of a fixed crossbeam (6) and cooperating with the threaded holes; the top of the lead screw (7) is connected to the driving shaft of the motor (8) and the bottom is arranged on the moving frame (9); a pulley (10) is arranged at the bottom of the moving frame (9) and a slide rail (11) matched with the pulley (10) is arranged below the pulley (10); a hinge hole is arranged at the top in which the lead screw (7) can rotate; and a push-pull cylinder (12) capable of pushing the moving frame (9) is arranged on one side; The motor (8), the push-pull cylinder (12), the power mechanism and the high-pressure water pump are all electrically connected to the PLC controller.

2. A cooling device for a wire rod roughing mill roll according to claim 1, characterized in that: The distance between each two adjacent spray nozzles (1) and the distance between each two adjacent water spray nozzles (2) are both 150 mm, and the distance between the upper row of spray nozzles (1) and the lower row of water spray nozzles (2) is 200 mm.

3. The cooling device for the rolling mill rolls of the wire rod roughing mill according to claim 1, characterized in that: The spray nozzle (1) and the water spray nozzle (2) and their water supply devices and moving devices are each provided in two sets, and are respectively located on both sides of the roller (17).

4. The cooling device for the rolling mill rolls of the wire rod roughing mill according to claim 1, characterized in that: The first main pipe, the second main pipe, the first branch pipe (4) and the second branch pipe (5) in the water supply device are all provided with valves, and each spray nozzle (1) and water spray nozzle (2) is provided with a switch, and the switches are all electrically connected to the PLC controller.

5. The cooling device for the rolling mill rolls of the wire rod roughing mill according to claim 1, characterized in that: The water inlet of the constant temperature water tank is connected to the factory water network, and a valve is provided on the water inlet pipe. A heating rod and a thermometer are provided inside the constant temperature water tank, and the heating rod, the thermometer and the valve on the water inlet pipe are all electrically connected to the PLC controller.

6. The cooling device for the rolls of the wire rod roughing mill according to claim 1, characterized in that: Each of the movable frames (9) is provided with two push-pull cylinders (12) respectively located at two ends of the movable frame (9), and the push-pull cylinders (12) are fixed by fixed columns (13).

7. The cooling device for the rolls of the wire rod roughing mill stand according to claim 1, characterized in that: The movable frame (9) is configured as a structure having a trapezoidal cross section and composed of a top plate, a bottom plate and two side plates, and a vertical plate for fixing the motor (8) is provided on the movable frame (9).

8. The cooling device for the rolling mill rolls of the wire rod roughing mill according to claim 7, characterized in that: Two water baffles (14) are arranged on the vertical plate, and a semicircular hole capable of accommodating the roll neck of the rolling mill is opened at the lower end of the water baffle (14).

9. The cooling device for the rolls of the wire rod roughing mill stand according to claim 1, characterized in that: There are four pulleys, which are distributed at four corner positions of the moving frame (9).

10. The cooling device for the rolling mill rolls of a wire rod roughing mill according to claim 1, characterized in that: A bearing is arranged in the hinge hole, and the inner ring of the bearing is fixed to the lead screw, and the outer ring is fixed to the inside of the hinge hole.

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