A uniform cooling device and production equipment for hot-rolled high-strength steel plates

Abstract

This invention discloses a uniform cooling device and production equipment for hot-rolled high-strength steel plates, belonging to the field of steel rolling technology. It solves the problem that existing cooling methods for hot-rolled high-strength steel plates cannot simultaneously achieve both cooling intensity and uniformity. The device includes multiple cooling units, each sequentially divided into a conventional cooling zone, a cooling-and-reheating zone, and a shielded cooling zone along the movement direction of the hot-rolled high-strength steel plate. The conventional cooling zone features water curtain cooling, laminar flow cooling, air mist cooling, and ultra-fast cooling modes. The cooling-and-reheating zone features air cooling, wind cooling, air mist cooling, and ultra-fast cooling modes. The shielded cooling zone features water curtain cooling, laminar flow cooling, air mist cooling, and ultra-fast cooling modes. Nozzles located at the edges of the shielded cooling zone are shielded by shielding plates. This invention can be used in the production of hot-rolled high-strength steel plates.

Description

Technical Field

[0001] This invention belongs to the field of steel rolling technology, and in particular to a uniform cooling device and production equipment for hot-rolled high-strength steel plates. Background Technology

[0002] Currently, for hot-rolled high-strength steel sheets, countries worldwide generally employ laminar flow, aerosol, or ultrafast cooling (UFC) methods for post-rolling controlled cooling to improve the steel sheet's strength. Among these, thin sheets treated with ultrafast cooling devices can have their tensile strength and yield strength increased by 100–300 MPa.

[0003] However, since the supercooling at both ends of the steel plate is a gradual temperature field, for medium-width plates (widths above 900mm, for example, 900–2200mm), the plate width range is relatively large, while the ultra-fast cooling zone is relatively short. Simply switching the cooling water on and off cannot achieve ideal temperature uniformity. Furthermore, ultra-fast cooling, due to the use of columnar nozzles, has a fast cooling rate but a narrow coverage area, which easily leads to uneven cooling within the thickness range, resulting in uneven microstructure and mechanical properties, as well as significant residual stress.

[0004] The aerosol cooling method can fully utilize the fundamental principle that the latent heat of vaporization of water is much higher than its specific heat in the cooling of hot-rolled high-strength steel plates, increasing the proportion of vaporization cooling in mixed cooling (including water contact heat exchange cooling, film boiling cooling, and vaporization cooling), thereby achieving the high-efficiency cooling requirement dominated by vaporization cooling. However, because vaporization takes time, the production line is relatively long, and the cooling rate is slow, it cannot meet users' requirements for ultra-fast cooling. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a uniform cooling device and production equipment for hot-rolled high-strength steel plates, which solves the problem that the existing cooling methods for hot-rolled high-strength steel plates cannot simultaneously achieve both cooling intensity and cooling uniformity.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] This invention provides a uniform cooling device for hot-rolled high-strength steel plates, comprising multiple cooling units. Each cooling unit is sequentially divided into a conventional cooling zone, a cooling and reheating zone, and a shielding cooling zone along the movement direction of the hot-rolled high-strength steel plate. The conventional cooling zone has water curtain cooling mode, laminar flow cooling mode, air mist cooling mode, and ultra-fast cooling mode. The cooling and reheating zone has air cooling mode, wind cooling mode, air mist cooling mode, and ultra-fast cooling mode. The shielding cooling zone has water curtain cooling mode, laminar flow cooling mode, air mist cooling mode, and ultra-fast cooling mode. The nozzles located at the edge of the shielding cooling zone are shielded by shielding plates.

[0008] Furthermore, the modes used in the conventional cooling zone, the cooling-return zone, and the shielded cooling zone are not entirely the same.

[0009] Furthermore, the total length of the uniform cooling device is 100-150m, including 10-15 cooling units.

[0010] Furthermore, it also includes a reverse spraying unit located on the discharge side of the shielded cooling zone. The fluid outlet direction of the reverse spraying unit is opposite to the movement direction of the hot-rolled high-strength steel plate. The reverse spraying unit sprays residual cooling water into the shielded cooling zone by spraying high-pressure airflow or high-pressure water.

[0011] Furthermore, the conventional cooling zone includes multiple conventional cooling nozzles arranged in multiple rows and columns to closely cover the entire width of the plate.

[0012] Furthermore, the cooling and reheating zone includes multiple cooling and reheating nozzles, which are arranged in multiple rows and columns, with gaps between two adjacent rows of cooling and reheating nozzles.

[0013] Furthermore, the shielded cooling zone includes multiple shielded cooling nozzles, which are arranged in multiple rows and columns to closely cover the entire width of the plate.

[0014] Furthermore, it also includes a shielding plate for shielding the cooling nozzles located at the edge; the shielding width of the shielding cooling area is 1 to 200 mm.

[0015] The present invention also provides a production equipment for hot-rolled high-strength steel plates, including the above-mentioned uniform cooling device.

[0016] Furthermore, it also includes a roughing rolling unit, a finishing rolling unit, and a coiling unit arranged in sequence, with a portion of the cooling units located between the roughing rolling unit and the finishing rolling unit, and the remaining cooling units located between the finishing rolling unit and the coiling unit.

[0017] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0018] The present invention provides a uniform cooling device for hot-rolled high-strength steel plates. It improves upon the conventional arrangement of ultra-fast cooling followed by laminar flow cooling by dividing the cooling unit into three cooling zones: a conventional cooling zone, a cooling-and-returning zone, and a shielding cooling zone. The conventional cooling zone achieves rapid overall cooling of the hot-rolled high-strength steel plate; the cooling-and-returning zone improves the cooling uniformity across the cross-section; and the shielding cooling zone regulates the cooling uniformity at the edges and center. This is particularly important when using ultra-fast cooling in the conventional cooling zone, as it regulates the cooling uniformity at the edges and center and reduces residual stress. Thus, by setting up these three cooling zones, targeted cooling can be achieved after the conventional cooling zone through the cooling-and-returning zone and the shielding cooling zone, effectively improving the overall uniformity across the cross-section of the hot-rolled high-strength steel plate and achieving uniform cooling.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0020] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0021] Figure 1 A schematic diagram of the cooling and reheating water supply unit and the cooling and reheating gas supply unit in the uniform cooling device for hot-rolled high-strength steel plates provided by the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of a conventional cooling nozzle in the uniform cooling device for hot-rolled high-strength steel plates provided by the present invention.

[0023] Figure 3 A schematic diagram of the structure of the production equipment for hot-rolled high-strength steel plates provided by the present invention;

[0024] Figure 4 This is a dynamic CCT curve of the 700MPa hot-rolled high-strength steel plate used in Embodiment 1 of the present invention.

[0025] Figure 5 This is a temperature drop curve diagram of the plate thickness direction surface and core of the conventional cooling zone, cooling and reheating zone, and shielded cooling zone in Embodiment 1 of the present invention.

[0026] Figure 6 The temperature drop curves of the edge and middle of the plate in the width direction corresponding to different processes in the shielding cooling zone of Embodiment 1 of the present invention are shown.

[0027] Figure 7The curves show a comparison of the measured residual stress in the width direction of the plate in Embodiment 1 of the present invention and the conventional cooling process.

[0028] Figure label:

[0029] 1-Roughing rolling unit; 2-Cooling unit; 3-Finishing rolling unit; 4-Section temperature detector; 5-Strip shape meter; 6-Conventional cooling nozzle; 7-Online residual stress detector; 8-Temperature tension detector; 9-Pinch roll; 10-Winding unit; 11-Air compressor; 12-Air tank; 13-Gas shut-off valve; 14-Gas regulating valve; 15-Gas flow meter; 16-Pressure transmitter; 17-Gas pressure gauge; 18-Gas distributor; 19-Infrared thermometer; 20-Water distributor; 21-Water storage tank; 22-Liquid shut-off valve; 23-Liquid regulating valve; 24-Liquid flow meter; 25-Hydraulic transmitter; 26-Liquid pressure gauge. Detailed Implementation

[0030] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and are used together with the invention to illustrate the principles of the invention.

[0031] This invention provides a uniform cooling device for hot-rolled high-strength steel plates, see [link to relevant documentation]. Figures 1 to 3 It includes multiple cooling units. Each cooling unit is divided into a conventional cooling zone, a cooling and reheating zone, and a shielded cooling zone along the movement direction of the hot-rolled high-strength steel plate. The conventional cooling zone has water curtain cooling mode, laminar flow cooling mode, air mist cooling mode, and ultra-fast cooling mode. The cooling and reheating zone has air cooling mode, wind cooling mode, air mist cooling mode, and ultra-fast cooling mode. The shielded cooling zone has water curtain cooling mode, laminar flow cooling mode, air mist cooling mode, and ultra-fast cooling mode. The nozzles located at the edge of the shielded cooling zone are shielded by shielding plates.

[0032] It should be noted that the above refers to the production of ultra-wide hot-rolled high-strength steel plates with a strength of 700MPa and a width of 900mm or more.

[0033] Depending on the process requirements, the modes of the conventional cooling zone, the cooling and reheating zone, and the shielded cooling zone can be arbitrarily selected. However, it is not recommended that the conventional cooling zone, the cooling and reheating zone, and the shielded cooling zone all adopt the same mode.

[0034] Existing technologies cannot simultaneously achieve both cooling intensity and cooling uniformity, resulting in hot-rolled high-strength steel plates, especially those exceeding 700 MPa, failing to meet user requirements in terms of plate shape and residual stress. Compared to existing technologies, the uniform cooling device for hot-rolled high-strength steel plates provided by this invention improves upon the conventional arrangement of ultra-fast cooling followed by laminar flow cooling. The cooling unit is divided into three cooling zones: a conventional cooling zone, a cooling-and-returning zone, and a shielding cooling zone. The conventional cooling zone achieves rapid overall cooling of the hot-rolled high-strength steel plate; the cooling-and-returning zone improves the cooling uniformity across the cross-section of the hot-rolled high-strength steel plate; and the shielding cooling zone adjusts the cooling uniformity at the edges and center. Especially when using ultra-fast cooling in the conventional cooling zone, the shielding cooling zone is crucial for adjusting the cooling uniformity at the edges and center and reducing residual stress. In this way, by setting up three cooling zones, targeted cooling can be carried out after the conventional cooling zone through the cooling and reheating zone and the shielding cooling zone, thereby effectively improving the overall uniformity within the cross-sectional area of ​​the hot-rolled high-strength steel plate and achieving uniform cooling of the hot-rolled high-strength steel plate.

[0035] For example, the total length of the uniform cooling device for hot-rolled high-strength steel plates is 100 to 150 m, and it includes 10 to 15 cooling units, each of which is 10 to 15 m long.

[0036] To reduce the impact of residual cooling water on the cooling uniformity of the next cooling unit, the above-mentioned uniform cooling device for hot-rolled high-strength steel plates also includes a reverse spraying unit located on the discharge side of the shielded cooling zone. The fluid outlet direction of the reverse spraying unit is opposite to the movement direction of the hot-rolled high-strength steel plate. The reverse spraying unit sprays residual cooling water into the shielded cooling zone by spraying high-pressure airflow or high-pressure water, thereby reducing the impact of residual cooling water on the cooling uniformity of the next cooling unit.

[0037] Specifically, the structure of the conventional cooling zone includes multiple conventional cooling nozzles 6 (e.g., columnar nozzles). These multiple conventional cooling nozzles 6 are arranged in multiple rows and columns to closely cover the entire width of the plate. In this way, in the conventional cooling zone, when the hot-rolled high-strength steel plate moves from the previous row of conventional cooling nozzles 6 to the next row of conventional cooling nozzles 6, there is basically no back-heating process, thus achieving rapid cooling.

[0038] Understandably, in order to supply cooling water and air to the conventional cooling nozzles 6 and enable multi-mode switching between water curtain cooling, laminar flow cooling, aerosol cooling, and ultra-fast cooling modes, the aforementioned conventional cooling zone also includes a conventional cooling water supply unit and a conventional cooling air supply unit, respectively connected to the conventional cooling nozzles 6. The conventional cooling water supply unit has a cooling water flow rate of 2000–10000 t / h, and the conventional cooling air supply unit has an air flow rate of 100–5000 m³ / h. 3 / h, the air-to-water ratio in the conventional cooling zone is 0.01 to 50, where the air-to-water ratio refers to the ratio of air to water per unit volume. This enables the conventional cooling zone to achieve a full coverage of cooling rates of 55 to 200℃ / s, ensuring sufficient cooling speed during the conventional cooling process to meet process requirements. At the same time, it can also effectively improve the surface quality of hot-rolled high-strength steel plates and prevent surface rusting.

[0039] To further control the cooling uniformity of the conventional cooling zone, for example, in the conventional cooling zone, the cooling water convexity from the middle to the edge of the hot-rolled high-strength steel plate along the width direction of the plate is 1 to 10 mm. It should be noted that the cooling water convexity refers to the difference between the residual thickness of the cooling water in the middle of the hot-rolled high-strength steel plate and the residual thickness of the cooling water at the edge of the hot-rolled high-strength steel plate.

[0040] Considering that the cooling rate of the conventional cooling zone is relatively fast, and the residence time of the cooling water on the upper surface of the hot-rolled high-strength steel plate is longer than that on the lower surface, it is easy to cause uneven cooling rates between the upper and lower surfaces. Therefore, the cooling rate of the conventional cooling zone on the upper surface of the hot-rolled high-strength steel plate is less than that of the conventional cooling zone on the lower surface of the hot-rolled high-strength steel plate. For example, the conventional cooling zone on the upper surface of the hot-rolled high-strength steel plate is a water curtain cooling mode, and the conventional cooling zone on the lower surface of the hot-rolled high-strength steel plate is an upper ultra-fast cooling mode.

[0041] It is worth noting that, due to the wall thickness of the nozzle, if a circular cylindrical nozzle is used, a certain gap will inevitably exist between two adjacent circular cylindrical nozzles, making it virtually impossible to achieve a tight, seamless coverage. Therefore, the sidewall shape of the aforementioned conventional cooling nozzle 6 is gear-shaped, see [reference needed]. Figure 2 The sidewalls of two adjacent conventional cooling nozzles 6 mesh, and the water outlet areas of two adjacent conventional cooling nozzles 6 overlap in the direction of movement of the hot-rolled high-strength steel plate, thereby enabling a tight and seamless coverage of multiple conventional cooling nozzles 6.

[0042] In order to further improve the cooling uniformity of the conventional cooling zone, the conventional cooling zone also includes a rotating gear and a drive motor for driving the rotating gear to rotate. The rotating gear meshes with one of the conventional cooling nozzles 6 in the conventional cooling zone (e.g., a conventional cooling nozzle 6 located at the end). In this way, the drive motor can sequentially drive the rotating gear, the conventional cooling nozzle 6 located at the end, and other meshing conventional cooling nozzles 6 to rotate simultaneously, thereby further improving the cooling uniformity of the conventional cooling zone.

[0043] Specifically, the structure of the cooling and reheating zone includes multiple cooling and reheating nozzles arranged in multiple rows and columns. There is a gap between two adjacent rows of cooling and reheating nozzles, for example, the gap size is 40-60mm. When the hot-rolled high-strength steel plate is between two adjacent rows of nozzles, there is a certain time gap during which it is not in the cooling medium, and a certain degree of reheating can be achieved. This ensures the cooling uniformity of the cross-section of the hot-rolled high-strength steel plate, so that the uniform cooling device can be truly used in the production of hot-rolled high-strength steel plates.

[0044] Understandably, in order to supply cooling water and air to the cooling and reheating nozzles and enable multi-mode switching between air cooling, wind cooling, aerosol cooling, and ultra-fast cooling modes, the aforementioned cooling and reheating zone also includes a cooling and reheating water supply unit and a cooling and reheating air supply unit respectively connected to the cooling and reheating nozzles. The airflow rate for wind cooling and aerosol cooling modes is 4000–5000 m³ / h. 3 With a water volume of 400-500 t / h and an air-to-water ratio controlled at 10-12.5, the cooling rate of the cooling and reheating zones can be fully covered at 1-50℃ / s, ensuring sufficient cooling speed during the cooling and reheating process to meet process requirements.

[0045] To further control the cooling uniformity of the cooling and reheating zone, for example, the cooling water convexity from the middle to the edge of the hot-rolled high-strength steel plate is 1 to 20 mm along the width direction of the plate.

[0046] For the structure of the cooling and reheating gas supply unit, see [link / reference]. Figure 1 Specifically, it includes an air compressor 11, an air tank 12, a gas shut-off valve 13, a gas regulating valve 14, a gas flow meter 15 (e.g., an FT orifice plate flow meter with a differential pressure transmitter), and a gas distributor 18 connected in sequence. The outlet of the gas distributor 18 is connected to a cooling and reheating nozzle through a gas pipe. A gas pressure transmitter 16 (e.g., a PT pressure transmitter) and a gas pressure gauge 17 (e.g., a PI pressure gauge) are provided on the connecting pipeline between the gas flow meter 15 and the gas distributor 18.

[0047] For the structure of the cooling and reheating gas supply unit, see [link / reference]. Figure 1 Specifically, it includes a water storage tank 21, a water pump, a booster pump, a liquid shut-off valve 22, a liquid regulating valve 23, a liquid flow meter 24, and a water distributor 20 connected in sequence. The outlet of the water distributor 20 is connected to a cooling and reheating nozzle through a water pipe. A hydraulic transmitter 25 (e.g., a PT pressure transmitter) and a liquid pressure gauge 26 (e.g., a PI pressure gauge) are installed on the connecting pipeline between the liquid flow meter 24 and the water distributor 20.

[0048] It is worth noting that during the cooling process, the temperature of the surface and core of the hot-rolled high-strength steel plate is crucial to the microstructure of the cooled hot-rolled high-strength steel plate. Therefore, the above-mentioned uniform cooling device also includes an infrared thermometer 19 for monitoring the surface temperature of the hot-rolled high-strength steel plate.

[0049] Specifically, the structure of the shielded cooling zone includes multiple shielded cooling nozzles (e.g., columnar nozzles) arranged in multiple rows and columns to closely cover the entire width of the plate. In this way, when the hot-rolled high-strength steel plate moves from the previous row of shielded cooling nozzles to the next row of shielded cooling nozzles in the shielded cooling zone, there is basically no back-heating process, achieving rapid cooling.

[0050] Understandably, in order to supply cooling water and air to the shielded cooling nozzles and enable multi-mode switching between water curtain cooling, laminar flow cooling, aerosol cooling, and ultra-fast cooling modes, the aforementioned shielded cooling zone also includes a shielded cooling water supply unit and a shielded cooling air supply unit, respectively connected to the shielded cooling nozzles. The cooling water flow rate of the shielded cooling water supply unit is 200–5000 t / h, and the air flow rate of the shielded cooling air supply unit is 50–2000 m³ / h. 3 The air-to-water ratio in the shielded cooling zone is 0.01 to 10, thus enabling a full coverage of the shielded cooling zone with a cooling rate of 0.5 to 100℃ / s.

[0051] To achieve edge shielding, the aforementioned shielded cooling zone also includes a shielding plate for shielding the shielded cooling nozzles located at the edges. For example, the shielding width of the shielded cooling zone is 1–200 mm.

[0052] It should be noted that, by setting up the shielded cooling zone, the cross-sectional temperature difference in the thickness direction of hot-rolled high-strength steel plates with a thickness of 1 to 20 mm is 10 to 20℃; for hot-rolled high-strength steel plates with a thickness greater than 20 mm and less than 100 mm, the cross-sectional temperature difference in the thickness direction is 10 to 30℃; and for hot-rolled high-strength steel plates with a thickness of more than 100 mm, the cross-sectional temperature difference in the thickness direction is 10 to 100℃.

[0053] Online (offline) non-destructive testing of residual stress primarily utilizes ultrasonic probes for detection. The results are compared with a zero-standard sample to obtain residual stress values, which then guide online adjustments to the rolling and cooling processes. This achieves perfect coupling between residual stress and the online cooling process, resulting in steel plates with low residual stress.

[0054] The present invention also provides a production equipment for hot-rolled high-strength steel plates, comprising a roughing mill unit 1, a finishing mill unit 3, a cross-sectional temperature detector 4, a plate shape detector 5, an online residual stress detector 7, a temperature tension detector 8, pinch rolls 9, and a coiling unit 10 arranged in sequence. A portion of the cooling units 2 are located between the roughing mill unit 1 and the finishing mill unit 3, and the remaining cooling units 2 are located between the finishing mill unit 3 and the coiling unit 10, to replace the current ultra-fast cooling, laminar flow cooling, or intermediate billet cooling. The cooling water crown of the cooling unit 2 located between the roughing mill and the finishing mill is adjusted according to the plate crown pattern fed back by the cross-sectional temperature detector 4 and the plate shape detector 5.

[0055] Compared with the prior art, the beneficial effects of the production equipment for hot-rolled high-strength steel plates provided by the present invention are basically the same as the beneficial effects of the uniform cooling device for hot-rolled high-strength steel plates provided above, and will not be described in detail here.

[0056] Considering that the online temperature gradient of the cross section of hot-rolled high-strength steel plate will affect the cooling uniformity of the hot-rolled high-strength steel plate, the cross section temperature detector 4 detects the online temperature gradient data of the cross section of the hot-rolled high-strength steel plate in real time and transmits it to the cooling controller. The cooling controller determines whether the online temperature gradient data is within the threshold range. If it exceeds the threshold range, the cooling water flow rate of the finishing mill cooling device is increased to increase the cooling rate. If it is below the threshold range, the cooling water flow rate of the finishing mill cooling device is decreased to decrease the cooling rate.

[0057] Similarly, considering that plate crown also affects the production quality of hot-rolled high-strength steel plates, the plate shaper 5 detects the plate crown of hot-rolled high-strength steel plates in real time and transmits it to the finishing mill controller. The finishing mill controller determines whether the plate crown exceeds the threshold. If it does, it adjusts the rolling force of the finishing mill to correct the shape of the hot-rolled high-strength steel plate.

[0058] To enable real-time adjustment of rolling and cooling processes based on the residual stress of hot-rolled high-strength steel sheets, the online residual stress detector 7 primarily utilizes an ultrasonic probe for detection. By comparing the residual stress with a zero standard sample, the residual stress value of the hot-rolled high-strength steel sheet is obtained. The rolling and cooling processes are then adjusted in real-time based on this residual stress. This achieves perfect coupling between residual stress and cooling processes, resulting in hot-rolled high-strength steel sheets with low residual stress.

[0059] Example 1

[0060] This embodiment uses 700MPa hot-rolled high-strength steel plates and has multiple cooling units. Some cooling units are located between the roughing and finishing rolling units, while the remaining cooling units are located between the finishing rolling unit and the coiling unit.

[0061] The uniform cooling device has a total length of 150m and contains 10 units. Each cooling unit is about 15m long and includes a conventional cooling zone, a cooling and reheating zone, and a shielding cooling zone. There are 2 cooling units between the roughing and finishing rolling units and 8 units between the finishing rolling unit and the coiling unit.

[0062] Figure 4 This is the dynamic CCT curve of the 700MPa hot-rolled high-strength steel plate used in this embodiment; Figure 5 This is a temperature drop curve diagram of the plate thickness direction surface and core of the conventional cooling zone, cooling and reheating zone, and shielded cooling zone in this embodiment; Figure 6 The temperature drop curves of the edge and middle of the plate width direction corresponding to different processes in the shielded cooling zone of this embodiment are shown. Figure 7 This is a comparison curve of the measured residual stress in the width direction of the plate in this embodiment and the conventional cooling process. Figure 7 It can be seen that the residual stress in this embodiment is lower, which is significantly better than that of conventional cooling processes.

[0063] Testing showed that the fastest cooling rate in this embodiment was approximately 200℃ / s. The temperature differences before the width-fixing mill, the roughing mill, and the coiler were 31℃, 7℃, and 3℃, respectively. The temperature differences between the edge and middle of the plate were 10℃ and 16℃, respectively. The temperature difference in the cooling and reheating zones was controlled within the range of 100-200℃. The final measured temperature difference across the plate width was controlled within 20℃, which is better than the 60℃ of conventional cooling processes. The residual stress measured in the embodiment and comparative examples was optimized from 80-210MPa to 20-80MPa, significantly reducing the residual stress of the high-strength steel plate and improving the forming performance of subsequent deep processing.

[0064] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An even cooling device for hot-rolled high-strength steel sheets, characterized by, It includes multiple cooling units. Each cooling unit is divided into a conventional cooling zone, a cooling and reheating zone, and a shielded cooling zone along the movement direction of the hot-rolled high-strength steel plate. The conventional cooling zone has water curtain cooling mode, laminar flow cooling mode, air mist cooling mode, and ultra-fast cooling mode. The cooling and reheating zone has air cooling mode, wind cooling mode, air mist cooling mode, and ultra-fast cooling mode. The shielded cooling zone has water curtain cooling mode, laminar flow cooling mode, air mist cooling mode, and ultra-fast cooling mode. The nozzles located at the edge of the shielded cooling zone are shielded by shielding plates. The conventional cooling zone, the cooling and reheating zone, and the shielded cooling zone do not employ the same patterns. The conventional cooling zone includes multiple conventional cooling nozzles, which are arranged in multiple rows and columns to closely cover the entire width of the plate. The sidewalls of the conventional cooling nozzles are gear-shaped, with the sidewalls of two adjacent conventional cooling nozzles meshing. The water outlet areas of two adjacent conventional cooling nozzles overlap in the direction of movement of the hot-rolled high-strength steel plate. The cooling and reheating zone includes multiple cooling and reheating nozzles, which are arranged in multiple rows and columns, with gaps between two adjacent rows of cooling and reheating nozzles. The cooling rate of the conventional cooling zone located on the upper surface of the hot-rolled high-strength steel plate is lower than that of the conventional cooling zone located on the lower surface of the hot-rolled high-strength steel plate.

2. The device for uniform cooling of a hot-rolled high-strength steel sheet according to claim 1, characterized by, The total length of the uniform cooling device is 100-150m, and it includes 10-15 cooling units.

3. The device for uniform cooling of hot-rolled high-strength steel sheet according to claim 1, characterized by, It also includes a reverse spraying unit located on the discharge side of the shielded cooling zone. The fluid outlet direction of the reverse spraying unit is opposite to the movement direction of the hot-rolled high-strength steel plate. The reverse spraying unit sprays residual cooling water into the shielded cooling zone by spraying high-pressure airflow or high-pressure water.

4. The device for uniform cooling of a hot-rolled high-strength steel sheet according to claim 1, characterized by, The shielded cooling zone includes multiple shielded cooling nozzles, which are arranged in multiple rows and columns to closely cover the entire width of the plate.

5. The device for uniform cooling of hot-rolled high-strength steel plates according to claim 1, characterized in that, It also includes a shielding plate for covering the cooling nozzles located at the edges; The shielding width of the shielding cooling zone is 1~200mm.

6. A production apparatus for hot-rolled high-strength steel sheets, characterized by comprising: Includes the uniform cooling device as described in any one of claims 1 to 5.

7. The production equipment for hot-rolled high-strength steel plates according to claim 6, characterized in that, It also includes a roughing rolling unit, a finishing rolling unit and a coiling unit arranged in sequence. A portion of the cooling units are located between the roughing rolling unit and the finishing rolling unit, and the remaining cooling units are located between the finishing rolling unit and the coiling unit.

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