Slab heavy press-down casting slab thickness tracking method

Abstract

The application provides a slab heavy press-down casting slab thickness tracking method, and belongs to the technical field of continuous casting, and comprises the following steps: according to the roll gap value of a fan-shaped section, a device inner arc limiting line is constructed below the inner arc of the fan-shaped section from the slab inlet of the fan-shaped section to the slab outlet of the fan-shaped section; the distance between the device inner arc limiting line and the outer arc roll surface of the fan-shaped section is set as the slab limiting thickness; in the length direction of the slab, the slab is divided into blocks according to the preset length, and when the blocks pass through different positions of the fan-shaped section, the thickness of the blocks is tracked and reset according to the preset tracking reset principle, so that the thickness tracking of the slab is completed. The application can solve the problem that there is no effective method for tracking the thickness of the slab in the process of slab heavy press-down in the prior art.

Description

Technical Field

[0001] This invention relates to the field of continuous casting technology, and more specifically, to a method for tracking the thickness of a slab under heavy pressure. Background Technology

[0002] During solidification, continuously cast slabs are prone to internal quality defects such as center segregation, porosity, and center shrinkage cavities, leading to substandard core quality in later rolled products. This is especially true for thick and extra-thick plates, where core defects are difficult to completely heal during rolling, resulting in failure to pass ultrasonic testing. Reducing the slab size during solidification can compensate for the liquid volume shrinkage, effectively mitigating core segregation, porosity, and shrinkage cavities. Therefore, it is widely used in slab continuous casting. Furthermore, practical experience shows that heavy reduction can increase the core density of thick slabs, allowing for lower rolling ratios while still meeting testing requirements. Studies have shown that by increasing core density through heavy reduction, the rolling ratio can be reduced from over 3.0 to below 2.0, significantly increasing the thickness of the rolled product. Conversely, this allows for thinning of the continuously cast slab, improving production efficiency and reducing costs.

[0003] Before and after pressing, the thickness of the billet will change significantly. The pressing process is a process in which the fan-shaped segment shapes the thickness of the billet. After pressing, the fan-shaped segment is forced to adapt to or interact with the thickness of the billet. The change in billet thickness brought about by the pressing process is the process of pressing shaping the quality of the billet. The interaction between the fan-shaped segment and the billet thickness after pressing still plays an important role in the quality of the billet and has a decisive effect on the service life of the equipment.

[0004] In summary, slab thickness tracking under heavy pressure is "the core of quality control, a barrier to equipment safety, a guarantee of high production efficiency, and the foundation for process optimization." Its accuracy directly determines whether the process under heavy pressure can achieve its expected goals. It is a key link connecting internal quality improvement in continuous casting, stable equipment operation, and subsequent rolling processes, playing an irreplaceable role in the product competitiveness and economic benefits of steel enterprises.

[0005] In billet tracking, the first step is to track the billet thickness during the pressing process. Only with accurate billet thickness tracking during pressing can subsequent thickness and roll gap tracking be accurate, thus achieving a dual optimization of process and equipment. In the light pressing process of slabs, the pressing amount is small, and inaccurate thickness tracking has less impact on process performance and equipment. However, with the implementation of heavy pressing technology, thickness tracking plays a more important role in process and equipment. Yet, current technologies lack effective methods for tracking billet thickness during heavy pressing of slabs.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] In view of the above problems, the purpose of this invention is to provide a method for tracking the thickness of cast billets under heavy slab pressure, so as to solve the problem that there is no effective method for tracking the thickness of cast billets during the heavy slab pressure process in the prior art, so as to provide data support for subsequent roll gap tracking, ensure the process effect under heavy pressure and improve the service life of equipment.

[0008] This invention provides a method for tracking the thickness of a cast slab under heavy pressure, comprising the following steps:

[0009] Based on the roll gap value of the sector segment, an inner arc limit line for the equipment is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

[0010] The distance between the inner arc limiting line of the equipment and the outer arc roller surface of the sector segment is set as the billet limiting thickness;

[0011] The billet is divided into blocks according to a preset length along its length. When a block passes through different positions of the sector segment, the thickness of the block is tracked and reset according to a preset tracking and reset principle to complete the tracking of the billet thickness. The preset tracking and reset principle is as follows: when the thickness of the block is greater than the billet limit thickness at the position, the thickness of the block is reset to the billet limit thickness at the position and used as the tracking thickness of the block; when the thickness of the block is less than or equal to the billet limit thickness at the position, the thickness of the block is used as the tracking thickness of the block.

[0012] Furthermore, a preferred embodiment is that the inner arc limiting line of the device is a linear inner arc limiting line, a trapezoidal inner arc limiting line, or a trapezoidal inner arc limiting line with pressing details.

[0013] Furthermore, a preferred embodiment is that when the inner arc roller of the sector segment is a frame type, the inner arc limiting line of the equipment is a linear inner arc limiting line.

[0014] Furthermore, a preferred embodiment is that the method for constructing the linear inner arc limiting line includes the following steps:

[0015] Determine the roll gap value at the inlet of the sector segment and the roll gap value at the outlet of the sector segment;

[0016] Based on the roll gap value at the billet inlet and the roll gap value at the billet outlet of the sector segment, a linear inner arc limiting line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

[0017] Furthermore, a preferred embodiment is that when the inner arc roller of the sector segment is freely movable and the sector segment is not located in a horizontal segment, or when the inner arc roller of the sector segment is frame-type, the inner arc limiting line of the equipment is a trapezoidal inner arc limiting line.

[0018] Furthermore, a preferred embodiment is that the method for constructing the trapezoidal inner arc limiting line includes the following steps:

[0019] Determine the roll gap value for each roll in the sector segment;

[0020] Based on the roll gap value of each roll in the sector segment, the location of the inner arc roll of the sector segment is taken as the billet thickness change point, and the billet thickness between the inner arc rolls is set to remain unchanged. A trapezoidal inner arc limit line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

[0021] Furthermore, a preferred embodiment is that when the inner arc roller of the sector segment is freely movable and the sector segment is not located in a horizontal segment, or when the inner arc roller of the sector segment is frame-type, the inner arc limiting line of the device is a trapezoidal inner arc limiting line with pressing details.

[0022] Furthermore, a preferred embodiment is that the method for constructing the trapezoidal inner arc limiting line with pressed details includes the following steps:

[0023] Determine the roll gap value for each roll in the sector segment;

[0024] The position of the inner arc roller of the sector segment is determined based on the roll gap value of each roller in the sector segment.

[0025] Based on the position of the inner arc rollers of the sector segment and the deformation of the billet after passing through rollers with different reduction amounts, the abrupt change point of the billet thickness is determined, and the billet thickness between the inner arc rollers is set to remain constant. A trapezoidal inner arc limiting line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

[0026] Furthermore, a preferred approach is to track and reset the thickness of the billet according to a preset tracking and reset principle to complete the thickness tracking process of the cast billet.

[0027] The thickness of the billet within the sector segment is tracked and reset according to a preset time period, and the thickness of the billet exiting the sector segment within the preset time period is also tracked and reset.

[0028] Furthermore, a preferred embodiment is that the preset length is 5mm-20mm; and / or the preset time period is 1s-3s.

[0029] As can be seen from the above technical solution, the slab thickness tracking method under heavy pressure provided by the present invention constructs an inner arc limit line of the equipment below the fan-shaped segment from the slab inlet to the slab outlet of the fan-shaped segment based on the roll gap value of the fan-shaped segment. The distance between the inner arc limit line and the outer arc roll surface is set as the slab limit thickness. The slab is divided into blocks according to a preset length in the length direction of the slab. When the block passes through different positions of the fan-shaped segment, the thickness of the block is compared with the slab limit thickness at its position to determine whether to reset the thickness tracking of the block to the slab limit thickness at the position of the block. This achieves dynamic tracking of the slab thickness. Precise slab thickness tracking provides data support for subsequent fan-shaped segment roll gap tracking, ensuring the pressing process effect and improving equipment life. Furthermore, precise tracking of the slab thickness ensures a reduction in subsequent billet pulling resistance under heavy pressure, ensuring stable and smooth production and avoiding the risk of billet stagnation.

[0030] To achieve the foregoing and related objectives, and in accordance with one or more aspects of the invention, the features described in detail below are included. Certain exemplary aspects of the invention are illustrated in detail below with reference to the accompanying drawings. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0031] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings, and with a more complete understanding of the invention.

[0032] Figure 1 This is a flowchart of a slab thickness tracking method under heavy pressure according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the inner arc limiting line of the linear device constructed according to Embodiment 1 of the present invention;

[0034] Figure 3 This is a schematic diagram of the inner arc limiting line of the trapezoidal device constructed according to Embodiment 1 of the present invention;

[0035] Figure 4 This is a schematic diagram of a trapezoidal inner arc limiting line with pressing details, constructed according to Embodiment 1 of the present invention;

[0036] Figure 5 This is a schematic diagram of the linear roll gap variation according to Embodiment 1 of the present invention;

[0037] Figure 6 This is a schematic diagram of billet thickness tracking according to Embodiment 1 of the present invention. Detailed Implementation

[0038] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details.

[0039] In view of the aforementioned lack of an effective method for tracking the thickness of the slab under heavy pressure in the existing technology, so as to provide data support for subsequent roll gap tracking, ensure the process effect under heavy pressure and improve the service life of equipment, this invention proposes a method for tracking the thickness of the slab under heavy pressure.

[0040] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0041] To illustrate the slab thickness tracking method under heavy pressure provided by this invention... Figure 1 The flowchart of a method for tracking slab thickness under heavy pressure according to an embodiment of the present invention is shown; Figure 2 The inner arc limiting line of the linear device constructed according to Embodiment 1 of the present invention is shown; Figure 3 The inner arc limiting line of the trapezoidal device constructed according to Embodiment 1 of the present invention is shown; Figure 4 A trapezoidal inner arc limiting line with pressing details is shown in the construction according to Embodiment 1 of the present invention; Figure 5 The linear roll gap variation according to Embodiment 1 of the present invention is shown; Figure 6 The billet thickness tracking according to Embodiment 1 of the present invention is shown.

[0042] like Figure 1 As shown, the slab thickness tracking method under heavy pressure provided by this invention mainly includes the following steps:

[0043] Step S1: Based on the roll gap value of the sector segment, construct the inner arc limit line of the equipment below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

[0044] Specifically, based on the known reduction amount of the sector segment, the roll gap value of the sector segment can be obtained. The roll gap value of the sector segment refers to the height of the gap between the upper and lower rolls of the sector segment in the continuous casting machine, and is a key parameter for controlling the billet size in the continuous casting process. Since the outer arc roll surface of the sector segment is a fixed surface, while the inner arc roll surface formed after the inner arc frame of the sector segment is reduced is variable, the constructed inner arc limiting line of the equipment is used to constrain the billet thickness, forming a hard constraint on the billet thickness direction, representing the maximum value of billet deformation at different positions within the sector segment.

[0045] As a preferred embodiment of the present invention, the inner arc limiting line of the device is a linear inner arc limiting line, a trapezoidal inner arc limiting line, or a trapezoidal inner arc limiting line with pressing details.

[0046] Specifically, based on the deformation characteristics of the fan-shaped segment of the slab, and using the roll gap value of the fan-shaped segment as the outer contour for tracking, different inner arc limit lines can be constructed according to the equipment type (different types of equipment may have different fan-shaped segment structures and forms under heavy slab pressure) to achieve dynamic tracking of the slab thickness of different equipment. Through accurate slab thickness tracking, data support is provided for subsequent fan-shaped segment roll gap tracking, ensuring the pressing process effect and improving equipment life.

[0047] As a preferred embodiment of the present invention, when the inner arc roller of the sector segment is a frame type, the inner arc limit line of the equipment is a linear inner arc limit line.

[0048] Specifically, if the inner arc of the sector segment is a frame deformation, all rollers cannot move freely, but are controlled by the deformation of the entire frame. In this way, the inner arc frame of the sector segment forms a linear change from the inlet roller to the outlet roller. Based on this, the inner arc limit line of the equipment is constructed as a linear inner arc limit line, which is the simplest to construct.

[0049] As a preferred embodiment of the present invention, the method for constructing a linear inner arc limiting line includes the following steps:

[0050] Determine the roll gap value at the inlet of the sector-shaped billet and the roll gap value at the outlet of the sector-shaped billet;

[0051] Based on the roll gap value at the billet inlet and the roll gap value at the billet outlet of the sector segment, a linear inner arc constraint line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

[0052] Specifically, for the construction of the linear inner arc limiting line, it is only necessary to determine the roll gap value at the inlet of the sector segment and the roll gap value at the outlet of the sector segment. After the upper frame (inner arc frame) is pressed down, it forms a shape with a large inlet and a small outlet. A straight line is formed from the inlet roll to the outlet roll along the roll surface of the inner arc roll to construct the linear inner arc limiting line.

[0053] As a preferred embodiment of the present invention, when the inner arc roller of the sector segment is freely movable and the sector segment is not located in the horizontal segment, or when the inner arc roller of the sector segment is frame-type, the inner arc limit line of the equipment is a trapezoidal inner arc limit line.

[0054] Specifically, if the inner arc roller of the sector segment can move freely and the sector segment is not located in the horizontal segment, then the inner arc limit line of the equipment is a trapezoidal inner arc limit line; when the inner arc roller of the sector segment is a frame type, the inner arc limit line of the equipment can be either a trapezoidal inner arc limit line or a linear inner arc limit line.

[0055] As a preferred embodiment of the present invention, the method for constructing the trapezoidal inner arc limiting line includes the following steps:

[0056] Determine the roll gap value for each roll in the sector segment;

[0057] Based on the roll gap value of each roll in the sector segment, the location of the inner arc roll of the sector segment is taken as the point of sudden change in billet thickness, and the billet thickness between the inner arc rolls is set to remain unchanged. A trapezoidal inner arc limit line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

[0058] Specifically, if the inner arc roller of the sector segment can move freely and the sector segment is not located in the horizontal segment, then the inner arc limit line of the equipment is a trapezoidal inner arc limit line. Even if the inner arc frame is deformed, it is impossible to form a linear inner arc limit line of the equipment. Therefore, it is necessary to construct a more complex trapezoidal inner arc limit line that is more in line with actual constraints. A sudden change point in the billet thickness is formed at the roller, and the billet thickness remains unchanged between the rollers. This forms a gradually decreasing trapezoidal step, i.e., a trapezoidal inner arc limit line.

[0059] As a preferred embodiment of the present invention, when the inner arc roller of the sector segment is freely movable and the sector segment is not located in the horizontal segment, or when the inner arc roller of the sector segment is frame-type, the inner arc limiting line of the device is a trapezoidal inner arc limiting line with pressing details.

[0060] Specifically, based on the trapezoidal inner arc limiting line, if the deformation of each roller during the pressing process and the elastic rebound after pressing are further considered, a trapezoidal inner arc limiting line with pressing details can be obtained.

[0061] As a preferred embodiment of the present invention, a method for constructing a trapezoidal inner arc limiting line with pressed-down details includes the following steps:

[0062] Determine the roll gap value for each roll in the sector segment;

[0063] The position of the inner arc roller of the sector segment is determined based on the roll gap value of each roller in the sector segment.

[0064] Based on the position of the inner arc rollers of the sector segment and the deformation of the billet after passing through rollers with different reduction amounts, the abrupt change point of the billet thickness is determined, and the billet thickness between the inner arc rollers is set to remain constant. A trapezoidal inner arc limiting line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

[0065] Specifically, the process of the billet passing through the fan-shaped section is a process in which the billet continuously passes through the rollers within the fan-shaped section. After passing through rollers with different reduction amounts, the thickness of the billet is shaped by the shape of the rollers. At the same time, a certain amount of rebound will occur after passing through the rollers. Therefore, considering the deformation of the billet after reduction, a trapezoidal inner arc limiting line with reduction details can be formed.

[0066] Step S2: Set the distance between the inner arc limit line of the equipment and the outer arc roller surface of the fan-shaped section as the billet limit thickness.

[0067] Specifically, based on the known reduction of the sector segment, the roll gap value of the sector segment can be obtained. The outer arc roll surface remains unchanged, while the inner arc limit line of the equipment constrains the billet thickness and is a hard constraint on the billet thickness direction. Therefore, it represents the maximum value of billet deformation at different positions within the sector segment. That is, the distance between the inner arc limit line of the equipment and the outer arc roll surface of the sector segment is the maximum value of billet deformation.

[0068] Step S3: Divide the billet into blocks according to a preset length along the length of the billet. When the billet passes through different positions of the fan-shaped segment, the thickness of the billet is tracked and reset according to the preset tracking and reset principle to complete the tracking of the billet thickness. The preset tracking and reset principle is as follows: when the thickness of the billet is greater than the billet limit thickness at the position, the thickness of the billet is reset to the billet limit thickness at the position and used as the tracking thickness of the billet; when the thickness of the billet is less than or equal to the billet limit thickness at the position, the thickness of the billet is used as the tracking thickness of the billet.

[0069] Specifically, the billet is divided into blocks along its length according to a preset length. This division is for better tracking and resetting of the thickness at different positions on the billet; it is not a true segmentation of the billet, but rather a division of its various locations. When a billet block passes through different positions on the sector segment, if the block's thickness is greater than the billet's limiting thickness at that position, the block's thickness is reset to the limiting thickness at that position and used as the tracking thickness. If the block's thickness is less than or equal to the limiting thickness at that position, the block's thickness is used as the tracking thickness.

[0070] In a preferred embodiment of the present invention, the thickness of the billet is tracked and reset according to a preset tracking and reset principle to complete the thickness tracking process of the cast billet.

[0071] The thickness of the billet within the sector is tracked and reset according to a preset time period, and the thickness of the billet exiting the sector within the preset time period is also tracked and reset.

[0072] Specifically, according to a preset time period, the thickness of the billet within the sector segment is periodically tracked and reset. If the billet thickness is greater than the corresponding billet limit thickness, it indicates the billet needs to be pressed down, and the tracked thickness is the billet limit thickness at that position. Otherwise, the billet thickness remains unchanged, meaning it is too small to be pressed down, and the tracked thickness is the billet thickness itself. Simultaneously, according to the preset time period, the thickness of billets that have passed through the sector segment exit and left the sector segment is periodically tracked and reset. If the billet thickness is greater than the sector segment exit height (i.e., greater than the billet limit thickness at the sector segment exit), it indicates the billet has been pressed down and deformed to the sector segment exit height, and the billet thickness is reset to the billet limit thickness at the sector segment exit, which is then used as the billet's tracked thickness. If the billet thickness is less than or equal to the sector segment exit height, the billet thickness remains unchanged, and the billet thickness is used as the billet's tracked thickness.

[0073] As a preferred embodiment of the present invention, the preset length is 5mm-20mm; and / or the preset time period is 1s-3s.

[0074] It should be noted that: the preset length is preferably, but not limited to, 5mm-20mm, and can be determined according to actual needs. The smaller the preset length, the higher the accuracy of billet thickness tracking. The preset time period is preferably, but not limited to, 1s-3s, and can be determined according to actual needs. The shorter the preset time period, the higher the accuracy of billet thickness tracking.

[0075] By constructing an inner arc limit line below the fan-shaped section from the billet inlet to the billet outlet based on the roll gap value of the fan-shaped section, and setting the distance between the inner arc limit line and the outer arc roll surface as the billet limit thickness, and dividing the billet into blocks of a preset length along the length direction, the system determines whether to reset the billet thickness tracking to the billet limit thickness at the location of the block as it passes through different positions of the fan-shaped section. This achieves dynamic tracking of the billet thickness, providing data support for subsequent fan-shaped section roll gap tracking, ensuring the pressing process effect and improving equipment lifespan. Furthermore, precise tracking of the billet thickness ensures reduced resistance during subsequent billet pulling under heavy pressure, guaranteeing stable and smooth production and avoiding the risk of billet stagnation.

[0076] To better illustrate the application of the slab thickness tracking method under heavy pressure provided by this invention, the following specific embodiments are provided:

[0077] Example 1

[0078] Taking a 300×1650mm thick plate casting machine in a steel plant as an example, traditional sector sections are all frame deformations. Generally, there are 7 pairs of rollers within a sector section. For sector sections arranged horizontally, once the reduction is known, the roller gap value of each roller in the sector section is also known. Figure 2 As shown, since the outer arc frame and outer arc roller surface of the sector segment remain stationary, an outer arc roller surface line is formed. After the upper frame (inner arc frame) is pressed down, a shape with a large inlet and a small outlet is formed. A straight line is formed from the inner arc inlet roller to the outlet roller along the roller surface of the inner arc roller, which is the constructed linear inner arc limiting line. This linear inner arc limiting line is considered to be continuously changing within the sector segment of the billet thickness.

[0079] For equipment types where the inner arc rollers can move freely, such as the new type of heavy-pressure fan-shaped section, or where the coordinate change of the inner arc rollers from the inlet roller to the outlet roller cannot be linearly described, it can be treated as ignoring the details of the billet pressing process by the pressing rollers. In the non-pressing area between the rollers, the billet thickness will not change. This approach is more in line with reality, resulting in... Figure 3 The thickness of the trapezoidal inner arc limiting line shown varies with the inner arc limiting line of the equipment structure as the billet passes through different positions of the fan-shaped segment.

[0080] When considering more details, since the billet does not directly become the thickness during the pressing process, but rather forms an arc-like thickness change with the pressing roller, such as... Figure 4 As shown, in more detailed actual situations, after the billet is pressed down, the billet thickness will rebound to a certain extent when the pressure disappears. That is, although there is no constraint on the billet between the two rolls, the billet thickness is not equal to the thickness of the thinnest part of the pressing roll, but has a certain amount of rebound. Therefore, a limit line with or without rebound can be constructed. Combined with the trapezoidal inner arc limit line, a trapezoidal inner arc limit line with pressing details is formed, which can make the billet thickness tracking result closer to the actual situation.

[0081] The preset time period is set to 3 seconds, the billet length used to track the billet thickness is 25 mm, and the casting machine's production speed is 0.5 m / min. This means that within one preset time period, the billet moves backward by 25 mm. For example... Figure 5 As shown, taking the constructed linear inner arc limiting line as an example, when the fan-shaped segment is pressed down by 10mm, the inlet roll gap value changes from 300mm to 290mm at the outlet.

[0082] like Figure 6 As shown, before the billet enters the pressing sector section, the original thickness of the billet is relatively large. As production continues and the preset time cycle continues, the billet enters the pressing sector section during its backward movement. When it reaches... Figure 6When the billet is in the middle position, the thickness of the billet obviously becomes the height of the inner arc limit line of the equipment, that is, the billet limit thickness. The thickness of the billet is reset, and so on to complete the continuous tracking of the billet thickness.

[0083] As can be seen from the above specific embodiments, the slab thickness tracking method under heavy pressure provided by the present invention constructs an inner arc limit line of the equipment below the fan-shaped segment from the slab inlet to the slab outlet of the fan-shaped segment based on the roll gap value of the fan-shaped segment, and sets the distance between the inner arc limit line and the outer arc roll surface as the slab limit thickness. Furthermore, the slab is divided into blocks according to a preset length along the length direction of the slab. When a block passes through different positions of the fan-shaped segment, the thickness of the block is compared with the slab limit thickness at its current position to determine whether to reset the slab thickness tracking to the slab limit thickness at that position. This achieves dynamic tracking of the slab thickness. Precise slab thickness tracking provides data support for subsequent fan-shaped segment roll gap tracking, ensuring improved pressing process effect and equipment lifespan. Furthermore, precise slab thickness tracking reduces subsequent billet pulling resistance under heavy pressure, ensuring stable and smooth production and avoiding the risk of slab stagnation.

[0084] The method for tracking slab thickness under heavy slab pressure according to the present invention has been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the method for tracking slab thickness under heavy slab pressure according to the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A method for tracking the thickness of a cast slab under heavy pressure, characterized in that, Includes the following steps: Based on the roll gap value of the sector segment, an inner arc limiting line is constructed below the inner arc of the sector segment, from the billet inlet to the billet outlet. This inner arc limiting line can be a linear inner arc limiting line, a trapezoidal inner arc limiting line, or a trapezoidal inner arc limiting line with pressing details. When the inner arc roller of the sector segment is frame-type, the inner arc limiting line is a linear inner arc limiting line. When the inner arc roller of the sector segment is freely movable and the sector segment is not located in a horizontal segment, or when the inner arc roller of the sector segment is frame-type, the inner arc limiting line is a trapezoidal inner arc limiting line. When the inner arc roller of the sector segment is freely movable and the sector segment is not located in a horizontal segment, or when the inner arc roller of the sector segment is frame-type, the inner arc limiting line is a trapezoidal inner arc limiting line with pressing details. The distance between the inner arc limiting line of the equipment and the outer arc roller surface of the sector segment is set as the billet limiting thickness; The billet is divided into blocks according to a preset length along its length. When a block passes through different positions of the sector segment, the thickness of the block is tracked and reset according to a preset tracking and reset principle to complete the tracking of the billet thickness. The preset tracking and reset principle is as follows: when the thickness of the block is greater than the billet limit thickness at the position, the thickness of the block is reset to the billet limit thickness at the position and used as the tracking thickness of the block; when the thickness of the block is less than or equal to the billet limit thickness at the position, the thickness of the block is used as the tracking thickness of the block.

2. The method for tracking slab thickness under heavy pressure according to claim 1, characterized in that, The method for constructing the linear inner arc limiting line includes the following steps: Determine the roll gap value at the inlet of the sector segment and the roll gap value at the outlet of the sector segment; Based on the roll gap value at the billet inlet and the roll gap value at the billet outlet of the sector segment, a linear inner arc limiting line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

3. The method for tracking slab thickness under heavy pressure according to claim 1, characterized in that, The method for constructing the trapezoidal inner arc limiting line includes the following steps: Determine the roll gap value for each roll in the sector segment; Based on the roll gap value of each roll in the sector segment, the location of the inner arc roll of the sector segment is taken as the billet thickness change point, and the billet thickness between the inner arc rolls is set to remain unchanged. A trapezoidal inner arc limit line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

4. The method for tracking slab thickness under heavy pressure according to claim 1, characterized in that, The method for constructing the trapezoidal inner arc limiting line with pressed details includes the following steps: Determine the roll gap value for each roll in the sector segment; The position of the inner arc roller of the sector segment is determined based on the roll gap value of each roller in the sector segment. Based on the position of the inner arc rollers of the sector segment and the deformation of the billet after passing through rollers with different reduction amounts, the abrupt change point of the billet thickness is determined, and the billet thickness between the inner arc rollers is set to remain constant. A trapezoidal inner arc limiting line is constructed below the inner arc of the sector segment from the billet inlet to the billet outlet of the sector segment.

5. The method for tracking slab thickness under heavy pressure according to claim 1, characterized in that, The thickness of the billet is tracked and reset according to a preset tracking and reset principle to complete the thickness tracking process of the cast billet. The thickness of the billet within the sector segment is tracked and reset according to a preset time period, and the thickness of the billet exiting the sector segment within the preset time period is also tracked and reset.

6. The method for tracking slab thickness under heavy pressure according to claim 5, characterized in that, The preset length is 5 mm - 20 mm; and / or, The preset time period is 1s-3s.

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