Ultra-fast Cooling Control Method for Medium Plate

Abstract

An embodiment of the present invention provides a method for controlling ultra-fast cooling of medium and heavy plates, which relates to the field of steel plate cooling. The aim is to improve the problem that it is not easy to control the head and tail plate shapes of steel plates with different sizes after cooling. The method for controlling ultra-fast cooling of medium and heavy plates includes: if the thickness H of the steel plate > 40 mm, then set K1 to 5%, K2 to 4%, N1 = L × K1, and N2 = L × K2; H is the thickness of the steel plate, K1 is the head shielding length of the steel plate, K2 is the tail shielding length of the steel plate, N1 is the head shielding length of the steel plate, N2 is the tail shielding length of the steel plate, and L is the rolling length of the steel plate. When the thickness of the steel plate exceeds 40 mm, the head shielding length and the tail shielding length of the steel plate can be accurately obtained according to the rolling length and the shielding length of the steel plate, so that precise control can be carried out, the shielding function can be fully exerted, the uniformity of steel plate cooling can be effectively improved, and the effect of controlling the head and tail plate shapes during the steel plate cooling process can be improved.

Description

Technical Field

[0001] The present invention relates to the field of steel plate cooling, and more particularly to a method for controlling ultra-fast cooling of medium and heavy plates. Background Art

[0002] The control level of accelerated cooling of steel plates is directly related to the shape and product performance of steel plates. With the production of high-grade and high-value-added steel grades, higher requirements are put forward for the control level of accelerated cooling. Since the commissioning of the ultra-fast cooling system, through the efforts of technical personnel, the hit rate of the final cooling temperature of steel plates has been continuously improved, and the cooling uniformity has also been improved to a certain extent. However, due to the large span of the rolled piece length, from 6 meters to 80 meters, it increases the difficulty of controlling the shape after cooling, especially the shape control of the head and tail. Summary of the Invention

[0003] The objectives of the present invention include, for example, providing a method for controlling ultra-fast cooling of medium and heavy plates, which can improve the problem that it is difficult to control the head and tail shapes of steel plates of different sizes after cooling.

[0004] The embodiments of the present invention can be implemented as follows:

[0005] The embodiments of the present invention provide a method for controlling ultra-fast cooling of medium and heavy plates, which is executed by an ultra-fast cooling system. The ultra-fast cooling system includes a roller table, multiple groups of slot headers, and multiple groups of high-density headers. The method for controlling ultra-fast cooling of medium and heavy plates includes:

[0006] If the thickness H of the steel plate > 40 mm, then set K1 to 5%, K2 to 4%, N1 = L × K1, N2 = L × K2;

[0007] H is the thickness of the steel plate, K1 is the head shielding length of the steel plate, K2 is the tail shielding length of the steel plate, N1 is the head shielding length of the steel plate, N2 is the tail shielding length of the steel plate, and L is the rolling length of the steel plate.

[0008] In addition, the method for controlling ultra-fast cooling of medium and heavy plates provided by the embodiments of the present invention may further have the following additional technical features:

[0009] Optionally, if 20 mm < H < 40 mm, then set K1 to 7% and K2 to 6%.

[0010] Optionally, if H ≤ 20 mm, then set K1 to 10% and K2 to 8%.

[0011] Optionally, the medium plate ultra-rapid cooling control method further includes: if the arching amplitude h1 in the middle of the head or tail of the steel plate is > 5 mm, the shielding coefficient of the upper surface is reduced by 0.2; if the arching amplitude h1 in the middle of the head or tail of the steel plate is < 5 mm, the shielding coefficient of the upper surface is reduced by 0.1.

[0012] Optionally, if the warping amplitude h2 on both sides of the head or tail of the steel plate is > 5 mm, the shielding coefficient of the lower surface is reduced by 0.2; if the warping amplitude h2 on both sides of the head or tail of the steel plate is < 5 mm, the shielding coefficient of the lower surface is reduced by 0.1.

[0013] Optionally, the medium plate ultra-rapid cooling control method further includes: the shielding coefficient W1 of the slit header is ≥ 0.7, and the shielding coefficient W2 of the high-density tube is ≥ 0.4.

[0014] Optionally, the medium plate ultra-rapid cooling control method further includes: if the thickness H of the steel plate is ≤ 19 mm, the range of the speed T of the roller table is 1.5 - 2.2 m / s, and the range of the acceleration A of the roller table is 0.011 - 0.018 m / s 2 。

[0015] Optionally, if the thickness H of the steel plate is > 19 and H ≤ 36 mm, the range of the speed T of the roller table is 1.1 - 1.3 m / s, and the range of the acceleration A of the roller table is 0.007 - 0.010 m / s 2 。

[0016] Optionally, if the thickness H of the steel plate is > 36 mm, the range of the speed T of the roller table is 1.0 ± 0.2 m / s, and the range of the acceleration A of the roller table is 0.005 ± 0.001 m / s 2 。

[0017] Optionally, the medium plate ultra-rapid cooling control method further includes: the number of the slit headers is four groups, the number of the high-density tubes is twenty groups, and the four groups of the slit headers and the twenty groups of the high-density tubes are arranged in sequence along the cooling movement direction of the steel plate;

[0018] If the final cooling temperature of the steel plate is lower than 600 °C, the slit headers are turned on; if the final cooling temperature of the steel plate is higher than 600 °C, the high-density tubes are turned on.

[0019] The beneficial effects of the medium plate ultra-rapid cooling control method according to the embodiments of the present invention include, for example:

[0020] Ultra-fast cooling control method for medium-thick plates, including: if the thickness H of the steel plate > 40 mm, then set K1 to 5%, K2 to 4%, N1 = L × K1, N2 = L × K2; H is the thickness of the steel plate, K1 is the head shielding length of the steel plate, K2 is the tail shielding length of the steel plate, N1 is the head shielding length of the steel plate, N2 is the tail shielding length of the steel plate, and L is the rolling plate length of the steel plate.

[0021] Before the implementation of this technology, the operators were not clear about the usage rules of the shielding function and basically did not adjust the parameters, which was equivalent to not using the head and tail shielding basically. The head and tail bending rate caused by cooling per month was 6.42%; after the implementation, when the thickness of the steel plate exceeded 40 mm, the head shielding length and tail shielding length of the steel plate could be accurately obtained according to the rolling length and shielding length of the steel plate, so that precise control could be carried out, the shielding function could be fully exerted, the uniformity of steel plate cooling could be effectively improved, and the effect of head and tail plate shape control during the steel plate cooling process could be improved. Greatly reduced the pressure of hot straightening and cold straightening, and shortened the product delivery period. Brief Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a block diagram of the ultra-fast cooling control method for medium-thick plates provided by the embodiments of the present invention;

[0024] Figure 2 It is a schematic structural diagram of the ultra-fast cooling system provided by the embodiments of the present invention;

[0025] Figure 3 It is the final cooling temperature curve diagram in Embodiment 1 of the ultra-fast cooling control method for medium-thick plates provided by the embodiments of the present invention;

[0026] Figure 4 It is the final cooling temperature curve diagram in Embodiment 2 of the ultra-fast cooling control method for medium-thick plates provided by the embodiments of the present invention;

[0027] Figure 5 It is the final cooling temperature curve diagram in Comparative Example 1 of the ultra-fast cooling control method for medium-thick plates provided by the embodiments of the present invention;

[0028] Figure 6 It is the final cooling temperature curve diagram in Comparative Example 2 of the ultra-fast cooling control method for medium-thick plates provided by the embodiments of the present invention.

[0029] Icons: 100 - steel plate; 200 - slit header; 300 - high-density tube. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0032] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] In the description of the present invention, it should be noted that if terms such as "upper", "lower", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

[0034] In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0035] It should be noted that the features in the embodiments of the present invention can be combined with each other without conflict.

[0036] The following will be combined with Figures 1 to 6 A detailed description will be given to the ultra-fast cooling control method for medium and heavy plates provided in this embodiment.

[0037] Please refer to Figure 1, an embodiment of the present invention provides a method for controlling ultra-fast cooling of medium-thick plates, which is executed by an ultra-fast cooling system. The ultra-fast cooling system includes a roller table, multiple groups of slot headers 200, and multiple groups of high-density headers 300. The method for controlling ultra-fast cooling of medium-thick plates includes: if the thickness H of the steel plate 100 > 40 mm, then set K1 to 5%, K2 to 4%, N1 = L × K1, and N2 = L × K2; H is the thickness of the steel plate 100, K1 is the head shielding length of the steel plate 100, K2 is the tail shielding length of the steel plate 100, N1 is the head shielding length of the steel plate 100, N2 is the tail shielding length of the steel plate 100, and L is the rolling plate length of the steel plate 100.

[0038] The ultra-fast cooling system includes 24 groups of headers. Groups 1-4 are slot headers 200, and groups 5-24 are high-density headers 300. It is divided into two areas, A and B. The upper frame is movable. Every four groups of header groups form a small group. The spraying directions of the first three groups of headers in each small group are the same as the movement direction of the steel plate 100, and the spraying direction of the last group of headers is opposite to the movement direction of the steel plate 100 to form a soft water seal. The instantaneous maximum water output of the conventional accelerated cooling ACC of the ultra-fast cooling system is 7000 m 3 / h, and the instantaneous maximum water output of the ultra-fast cooling UFC is 10000 m 3 / h; for steel plates of different specifications and grades, the initial temperature and the final temperature are different. For example, the starting cooling temperature of the conventional low-alloy Q355B plate is 770 - 800 °C, and the final cooling temperature is 600 - 660 °C. The spraying pressure of the conventional accelerated cooling ACC is 0.2 MPa, the height of the A-section frame is 300 mm, and the height of the B-section frame is 400 mm; the ultra-fast cooling UFC is 0.5 Mpa, the height of the A-section frame is 250 mm, and the height of the B-section frame is 400 mm; under the condition of fixed pressure, the flow rate is fixed. When designing the nozzles, slot nozzles with high uniform cooling and high-density fast-cooling nozzles are used, and a certain spraying pressure is adopted. At the same time, they are installed at a certain specific angle during the installation process, thereby greatly reducing the residual water on the surface of the steel plate 100, enabling the steel plate 100 to have extremely high cooling uniformity during the cooling process in the transverse and longitudinal directions, reducing the internal stress of the steel plate 100 after cooling, and reducing the tendency of the shape of the steel plate 100 to deteriorate subsequently.

[0039] The head and tail shielding adopts a flow shielding method, that is, the flow is small within a certain range at the head and tail, and the flow is normal in the middle, which can alleviate the problem of temperature difference between the head, middle and tail of the steel plate 100. According to the law of the thickness and length of the steel plate 100, that is, thick plates are short, thin plates are long, the passing speed at the head is slow, and the passing speed at the tail is fast. Specifically, when the thickness of the steel plate 100 exceeds 40 mm, the head shielding length and the tail shielding length of the steel plate 100 can be accurately obtained according to the rolling length and the shielding length of the steel plate 100, so as to be accurately controlled, the shielding function can be fully exerted, the uniformity of the cooling of the steel plate 100 can be effectively improved, and the effect of controlling the head and tail plate shape during the cooling of the steel plate 100 can be improved. The pressure of hot straightening and cold straightening is greatly reduced, and the product delivery period is shortened.

[0040] In this embodiment, if 20 mm < H < 40 mm, then K1 is set to 7%, and K2 is set to 6%. The thickness of the steel plate 100 is 20 - 40 mm, the shielding length of the plate head is fixed at 7%, and the shielding length of the plate tail is fixed at 6%.

[0041] In this embodiment, if H ≤ 20 mm, then K1 is set to 10%, and K2 is set to 8%. For plates with a thickness ≤ 20 mm, the shielding length of the plate head is fixed at 10%, and the shielding length of the plate tail is fixed at 8%.

[0042] It should be noted that the shielding length and shielding coefficient of the upper and lower surfaces can be set separately in groups, with a total of 8 groups, namely the upper head shielding amount groups 1 - 4, the upper tail shielding amount groups 1 - 4, the lower head shielding amount groups 1 - 4, the lower tail shielding amount groups 1 - 4, the upper head shielding amount groups 5 - 24, the upper tail shielding amount groups 5 - 24, the lower head shielding amount groups 5 - 24, and the lower tail shielding amount groups 5 - 24.

[0043] In this embodiment, the ultra-rapid cooling control method for medium-thick plates further includes: the number of slit headers 200 is four groups, the number of high-density headers 300 is twenty groups, and the four groups of slit headers 200 and the twenty groups of high-density headers 300 are arranged in sequence along the cooling movement direction of the steel plate 100; if the final cooling temperature of the steel plate 100 is lower than 600 °C, then the slit headers 200 are opened; if the final cooling temperature of the steel plate 100 is higher than 600 °C, then the high-density headers 300 are opened.

[0044] According to the characteristics of the header arrangement, one group of headers in each small group that is opposite to the running direction of the steel plate 100 is not shielded to avoid affecting the water seal effect, and the other headers are shielded when the corresponding group is opened. If the 4 groups of slit headers 200 are opened, the shielding parameters of the slit headers 200 are preferentially adjusted. Groups 1 - 4 are slit headers 200, and the slit headers 200 have a large water volume and strong cooling capacity, and are mainly opened for varieties with a process final cooling temperature below 600 °C; groups 5 - 24 are high-density headers 300, with a small water volume and moderate cooling capacity. For the steel plate 100 with a process final cooling temperature above 600 °C, opening the high-density headers 300 can meet the process requirements.

[0045] In this embodiment, the ultra-fast cooling control method for medium and thick plates also includes: if the arch amplitude h1 in the middle of the head or tail of the steel plate 100 is greater than 5mm, the shielding coefficient of the upper surface is reduced by 0.2; if the arch amplitude h1 in the middle of the head or tail of the steel plate 100 is less than 5mm, the shielding coefficient of the upper surface is reduced by 0.1.

[0046] In this embodiment, the method for controlling ultra-fast cooling of medium and thick plates further includes: a shielding coefficient W1 of the slot header 200 is ≥ 0.7, and a shielding coefficient W2 of the high-density tube 300 is ≥ 0.4.

[0047] When the head of the steel plate 100 is arched in the middle, the upper surface shielding coefficient is reduced; if the plate shape is still not improved when the shielding coefficient reaches the lower limit, the lower surface shielding coefficient is increased. When the tail of the steel plate 100 is arched in the middle, the upper surface shielding coefficient is reduced; if the plate shape is still not improved when the shielding coefficient reaches the lower limit, the lower surface shielding coefficient is increased. When the arch in the middle of the steel plate 100 is more than 5mm, the shielding coefficient changes by 0.2; when the arch in the middle of the steel plate 100 is less than 5mm, the shielding coefficient changes by 0.1. The shielding coefficient of the slot manifold 200 is not less than 0.7, and the shielding coefficient of the high-density tube 300 is not less than 0.4.

[0048] Specifically, if the bulge in the middle of the head of the steel plate 100 exceeds 5 mm, the shielding factor of the upper surface is reduced by 0.2 until the shielding factor of the slot header 200 is equal to 0.7, or the shielding factor of the high-density tube 300 is equal to 0.4, and the shielding factor of the lower surface is increased. If the bulge in the middle of the tail of the steel plate 100 exceeds 5 mm, the shielding factor of the upper surface is reduced by 0.2 until the shielding factor of the slot header 200 is equal to 0.7, or the shielding factor of the high-density tube 300 is equal to 0.4, and the shielding factor of the lower surface is increased.

[0049] In this embodiment, if the warping amplitude h2 of both sides of the head or tail of the steel plate 100 is greater than 5mm, the shielding coefficient of the lower surface is reduced by 0.2; if the warping amplitude h2 of both sides of the head or tail of the steel plate 100 is less than 5mm, the shielding coefficient of the lower surface is reduced by 0.1.

[0050] When the two sides of the head of the steel plate 100 are warped, the shielding coefficient of the lower surface is reduced; if the plate shape is still not improved when the shielding coefficient reaches the lower limit, the shielding coefficient of the upper surface is increased; when the two sides of the tail of the steel plate 100 are warped, the shielding coefficient of the lower surface is reduced; if the plate shape is still not improved when the shielding coefficient reaches the lower limit, the shielding coefficient of the upper surface is increased. When the two sides of the steel plate 100 are warped by more than 5mm, the shielding coefficient changes by 0.2; when the two sides of the steel plate 100 are warped by less than 5mm, the shielding coefficient changes by 0.1. Similarly, the shielding coefficient of the slot manifold 200 is not less than 0.7, and the shielding coefficient of the high-density tube 300 is not less than 0.4.

[0051] Specifically, if the upward warping amplitude on both sides of the head of the steel plate 100 exceeds 5 mm, the shielding coefficient of the upper surface is reduced by 0.2 until the shielding coefficient of the slit header 200 is equal to 0.7 or the shielding coefficient of the high-density tube 300 is equal to 0.4, and then the shielding coefficient of the lower surface is increased. If the upward warping amplitude on both sides of the tail of the steel plate 100 exceeds 5 mm, the shielding coefficient of the upper surface is reduced by 0.2 until the shielding coefficient of the slit header 200 is equal to 0.7 or the shielding coefficient of the high-density tube 300 is equal to 0.4, and then the shielding coefficient of the lower surface is increased.

[0052] In this embodiment, the ultra-fast cooling control method for medium and heavy plates further includes: if the thickness H of the steel plate 100 is ≤ 19 mm, the range of the speed T of the roller table is 1.5 - 2.2 m / s, and the range of the acceleration A of the roller table is 0.011 - 0.018 m / s 2 。

[0053] The setting range of the ultra-fast cooling roller speed is 0.5 - 2.5 m / s, and the setting range of the acceleration is 0.001 - 0.02 m / s 2 , and the upper limits of the speed and acceleration values have been set during the system design.

[0054] In this embodiment, if the thickness H of the steel plate 100 is > 19 and H ≤ 36 mm, the range of the speed T of the roller table is 1.1 - 1.3 m / s, and the range of the acceleration A of the roller table is 0.007 - 0.010 m / s 2 。

[0055] In this embodiment, if the thickness H of the steel plate 100 is > 36 mm, the range of the speed T of the roller table is 1.0 ± 0.2 m / s, and the range of the acceleration A of the roller table is 0.005 ± 0.001 m / s 2 。

[0056] Specifically, the relationship between the steel plate thickness and the speed and acceleration is shown in Table 1.

[0057] Table 1

[0058]

[0059] Two sets of examples and two sets of comparative examples are provided below to illustrate the relationship between the head and tail bending rates and the final cooling temperature curve diagrams after adjusting the shielding coefficient and shielding length for four groups of steel plates with different sizes. See Table 2.

[0060] Table 2 Example 1:

[0061]

[0062] Example 2:

[0063]

[0064] Comparative Example 1:

[0065]

[0066] Comparative Example 2:

[0067]

[0068] Two groups of examples and two groups of comparative examples are provided below to illustrate that after using the present technical solution, the head and tail bending rate is reduced to 2.89%, as shown in Table 3.

[0069] Table 3

[0070]

[0071] Before the implementation of this technology, the operators were not clear about the usage rules of the shielding function and basically did not adjust the parameters, which was equivalent to hardly using the head and tail shielding. The head and tail bending rate caused by cooling was 6.42% per month; after the implementation, the operators mastered the usage rules. After the technicians fixed the initial values, the operators could adjust the shielding parameters in real time according to the plate shape, reducing the head and tail bending rate caused by cooling to 2.89% per month, greatly reducing the pressure of hot straightening and cold straightening, and shortening the product delivery period.

[0072] A method for controlling ultra-fast cooling of medium-thick plates provided in this example has at least the following advantages:

[0073] When the thickness of the steel plate 100 exceeds 40 mm, the head shielding length and the tail shielding length of the steel plate 100 can be accurately obtained according to the rolling length and the shielding length of the steel plate 100, so as to enable precise control, the shielding function can be fully exerted, effectively improving the cooling uniformity of the steel plate 100 and the control effect of the head and tail plate shape during the cooling process of the steel plate 100. Greatly reducing the pressure of hot straightening and cold straightening, and shortening the product delivery period.

[0074] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for controlling ultra-rapid cooling of medium-thick plates, which is implemented by an ultra-rapid cooling system. The ultra-rapid cooling system includes a roller table, multiple groups of slot headers (200), and multiple groups of high-density tubes (300), and is characterized in that, The ultra-fast cooling control method for medium-thick plates includes: If the thickness H of the steel plate (100) > 40 mm, then set K1 to 5%, K2 to 4%, N1 = L × K1, and N2 = L × K2; H is the thickness of the steel plate (100), K1 is the head shielding length of the steel plate (100), K2 is the tail shielding length of the steel plate (100), N1 is the head shielding length of the steel plate (100), N2 is the tail shielding length of the steel plate (100), and L is the rolling plate length of the steel plate (100); The ultra-fast cooling control method for medium-thick plates further includes: If the middle arching amplitude h1 of the head or tail of the steel plate (100) > 5 mm, then reduce the shielding coefficient of the upper surface by 0.2; if the middle arching amplitude h1 of the head or tail of the steel plate (100) < 5 mm, reduce the shielding coefficient of the upper surface by 0.

1.

2. The ultra-fast cooling control method for medium-thick plates according to claim 1, characterized in that: If 20 mm < H < 40 mm, then set K1 to 7% and K2 to 6%.

3. The ultra-fast cooling control method for medium-thick plates according to claim 2, characterized in that: If H ≤ 20 mm, then set K1 to 10% and K2 to 8%.

4. The ultra-fast cooling control method for medium-thick plates according to claim 1, characterized in that: If the upward warping amplitude h2 of both sides of the head or tail of the steel plate (100) > 5 mm, then reduce the shielding coefficient of the lower surface by 0.2; if the upward warping amplitude h2 of both sides of the head or tail of the steel plate (100) < 5 mm, then reduce the shielding coefficient of the lower surface by 0.

1.

5. The method for controlling ultra-fast cooling of medium and heavy plates according to claim 4, characterized in that, The ultra-fast cooling control method for medium-thick plates further includes: The shielding coefficient W1 of the slit header (200) ≥ 0.7, and the shielding coefficient W2 of the high-density header (300) ≥ 0.

4.

6. The ultra-fast cooling control method for medium and heavy plates according to any one of claims 1-3, characterized in that The ultra-fast cooling control method for medium-thick plates further includes: If the thickness H of the steel plate (100) is ≤ 19 mm, the speed T of the roller table ranges from 1.5 to 2.2 m / s, and the acceleration A of the roller table ranges from 0.011 to 0.018 m / s 2 .

7. The ultra-fast cooling control method for medium-thick plates according to claim 6, characterized in that: If the thickness H of the steel plate (100) is greater than 19 and H ≤ 36 mm, the speed T of the roller table ranges from 1.1 to 1.3 m / s, and the acceleration A of the roller table ranges from 0.007 to 0.010 m / s 2 .

8. The ultra-fast cooling control method for medium-thick plates according to claim 7, characterized in that: If the thickness H of the steel plate (100) is > 36 mm, the speed T of the roller table ranges from 1.0 ± 0.2 m / s, and the acceleration A of the roller table ranges from 0.005 ± 0.001 m / s 2 .

9. The medium and heavy plate ultra-fast cooling control method according to claim 1, characterized in that The ultra-fast cooling control method for medium-thick plates further includes: The number of the slit headers (200) is four groups, the number of the high-density headers (300) is twenty groups, and the four groups of the slit headers (200) and the twenty groups of the high-density headers (300) are arranged in sequence along the cooling movement direction of the steel plate (100); If the final cooling temperature of the steel plate (100) is lower than 600 °C, then turn on the slit header (200); If the final cooling temperature of the steel plate (100) is higher than 600 °C, then turn on the high-density header (300).

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