Slab heavy press-down sector segment roll gap tracking method

Abstract

The application provides a slab heavy press-down fan-shaped segment roll gap tracking method, and belongs to the technical field of continuous casting. The method comprises the following steps: according to known slab thickness tracking data, the proportion of thin slabs in the current fan-shaped segment is counted; if the current fan-shaped segment is located before the reference position of the slab without bulging capacity, and the proportion of thin slabs meets the preset thin slab proportion condition for ensuring the press-down effect, the roll gap value of the current fan-shaped segment is reset according to the preset strategy for ensuring the press-down effect; if the current fan-shaped segment is located after the reference position of the slab without bulging capacity, and the proportion of thin slabs meets the preset thin slab proportion condition for ensuring the press-down equipment, the roll gap value of the current fan-shaped segment is reset according to the preset strategy for ensuring the press-down equipment, so as to complete the tracking of the roll gap of the fan-shaped segment. The application can solve the problem that there is no effective method for tracking the roll gap of the fan-shaped segment in the process of slab heavy press-down in the prior art, so as to ensure the press-down process effect and improve the service life of the fan-shaped segment equipment.

Description

Technical Field

[0001] This invention relates to the field of continuous casting technology, and more specifically, to a method for tracking the roll gap in a sector under heavy pressure on a slab. 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 safeguard for 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] The tracking of the sector section roll gap after pressing has a decisive impact on the process effect and equipment life. If the adjacent sector section cannot be continuously pressed after pressing, the pressing process effect will be affected. If the sector section roll gap is too large, exceeding the billet thickness, it will cause the billet and sector section to separate, resulting in the roll not rotating and being baked by the high-temperature billet, reducing the equipment life. If the sector section roll gap is set smaller than the actual billet thickness, it will definitely cause the billet to be pressed, and the equipment will need to withstand greater force, thus reducing the equipment life and greatly increasing the billet pulling resistance, which may cause billet stagnation accidents. In the light pressing process of slab, the pressing amount is small, and the inaccurate tracking of the sector section has less impact on the process effect and equipment. However, with the implementation of heavy pressing technology, the role of sector section tracking in the process and equipment is more important. Currently, there is a lack of effective methods for tracking the sector section in heavy pressing of slabs, which can ensure the pressing process effect and improve the equipment life of the sector section.

[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 roll gap of a sector section under heavy slab pressing, so as to solve the problem that there is no effective method for tracking the sector section during the heavy slab pressing process in the prior art, so as to ensure the pressing process effect and improve the service life of the sector section equipment.

[0008] This invention provides a method for tracking the roll gap in a sector section of a slab under heavy pressure, comprising the following steps:

[0009] Based on the known billet thickness tracking data, the percentage of thin billets in the current sector segment is calculated; wherein, the percentage of thin billets in the sector segment is the ratio of the length of the billet that has been pressed down in the current sector segment to the total length of the billets in the current sector segment.

[0010] If the current sector segment is located before the reference position for the billet's no-bulging capability, and the proportion of thin billets in the sector segment meets the preset thin billet proportion condition for ensuring the pressing effect, the roll gap value of the current sector segment is reset according to the preset pressing effect strategy; if the current sector segment is located after the reference position for the billet's no-bulging capability, and the proportion of thin billets in the sector segment meets the preset thin billet proportion condition for ensuring the pressing device, the roll gap value of the current sector segment is reset according to the preset pressing device strategy, so as to complete the tracking of the roll gap of the sector segment.

[0011] Furthermore, a preferred embodiment is that, based on known billet thickness tracking data, the step of calculating the proportion of thin billets in the current sector segment includes:

[0012] Based on the known billet thickness tracking data, the length of the billet that has been pressed down in the current sector segment is calculated.

[0013] The percentage of the length of the billet that has been pressed down in the current sector segment to the total length of the billet in the current sector segment is taken as the percentage of the thin billet in the current sector segment.

[0014] Furthermore, a preferred embodiment is that the preset strategy for ensuring the pressing effect is as follows:

[0015] When the proportion of thin billets in the current sector segment is 5%-10%, the roll gap values ​​of the billet inlet and the billet outlet of the current sector segment are reset to the thickness values ​​of the billet that has already been pressed down.

[0016] Furthermore, a preferred embodiment is that the preset strategy for ensuring the pressing effect is as follows:

[0017] When the proportion of thin billets in the current sector segment is 5%, the roll gap values ​​of the billet inlet and the billet outlet of the current sector segment are reset to the thickness value of the billet that has been pressed down.

[0018] Furthermore, a preferred embodiment is that the preset strategy for ensuring the pressing effect is as follows:

[0019] When the proportion of thin billets in the current sector segment is 1%-5%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has been pressed down.

[0020] When the proportion of thin billets in the current sector segment is 40%-60%, the roll gap value at the billet exit of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0021] Furthermore, a preferred embodiment is that the preset strategy for ensuring the pressing effect is as follows:

[0022] When the proportion of thin billets in the current sector segment is 5%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has been pressed down.

[0023] When the proportion of thin billets in the current sector segment is 50%, the roll gap value at the billet exit of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0024] Furthermore, a preferred embodiment is that the preset guarantee pressing device strategy is as follows:

[0025] When the proportion of thin billets in the current sector segment is more than 95%, the roll gap values ​​of the billet inlet and the billet outlet of the current sector segment are reset to the thickness values ​​of the billet that has been pressed down.

[0026] Furthermore, a preferred embodiment is that the preset guarantee pressing device strategy is as follows:

[0027] When the proportion of thin billets in the current sector segment is 50%-60%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has been pressed down.

[0028] When the proportion of thin billets in the current sector segment is more than 95%, the roll gap value at the billet exit of the current sector segment is reset to the thickness value of the billet that has been pressed down.

[0029] Furthermore, a preferred embodiment is that the preset guarantee pressing device strategy is as follows:

[0030] When the proportion of thin billets in the current sector segment is 50%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0031] In addition, a preferred embodiment is that the reference position for the bulge-free capability of the cast billet is the position on the cast billet where the center temperature of the cast billet is 100℃-200℃ lower than the solidus temperature.

[0032] As can be seen from the above technical solution, the slab heavy-pressure sector roll gap tracking method provided by the present invention, based on known slab thickness tracking data, calculates the ratio of the length of the slab that has been pressed into the current sector to the total length of the slab in the current sector, i.e., calculates the proportion of thin slabs in the current sector; if the current sector is located before the reference position where the slab has no bulging capacity, and the proportion of thin slabs in the sector meets the preset thin slab proportion condition for ensuring the pressing effect, then the roll gap value of the current sector is reset according to the preset pressing effect strategy, i.e., when the slab is relatively soft, the roll gap value of the current sector is reset while mainly ensuring the pressing effect on the slab; if the current sector is located after the reference position where the slab has no bulging capacity, and the proportion of thin slabs in the sector meets the preset pressing effect condition, then the roll gap value of the current sector is reset according to the preset pressing effect strategy. The system determines the minimum thickness of the billet in the pressing equipment and resets the roll gap value of the current sector segment according to a preset strategy to ensure the pressing effect. Specifically, when the billet is relatively hard, the roll gap value of the current sector segment is reset while prioritizing equipment lifespan. This allows for the reset of the roll gap value based on the billet's hardness and the tracking of changes in the billet thickness. Different strategies are employed to ensure both the pressing effect and equipment lifespan. This ensures higher pressing when the billet is softer and lower stress on the equipment when the billet is harder, thus determining the optimal timing for resetting (tracking or updating) the roll gap value of the sector segment. This achieves the technical effect of ensuring both the pressing process and the equipment's lifespan and stable production. It effectively improves production stability and efficiency while reducing production costs.

[0033] 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

[0034] 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.

[0035] Figure 1 This is a flowchart of a method for tracking the roll gap in a sector section of a slab under heavy pressure, according to an embodiment of the present invention.

[0036] Figure 2 This is a schematic diagram showing the ratio of the length of the billet that has been pressed down to the total length of the billet within the current sector segment according to Embodiment 1 of the present invention;

[0037] Figure 3 This is a schematic diagram showing the proportion of the thin blank in the current sector segment within the sector segment to ensure the optimal pressing effect according to Embodiment 1 of the present invention.

[0038] Figure 4 This is a schematic diagram showing the proportion of thin blanks in the current sector segment within the sector segment to ensure the optimal lifespan of the equipment according to Embodiment 1 of the present invention. Detailed Implementation

[0039] 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.

[0040] In view of the lack of an effective method for tracking the sector section during the heavy pressing of slabs in the aforementioned existing technologies, so as to ensure the pressing process effect and improve the service life of the sector section equipment, this invention proposes a method for tracking the roll gap of the sector section under heavy pressing of slabs.

[0041] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0042] To illustrate the method for tracking the roll gap in the sector section of a slab under heavy pressure provided by this invention... Figure 1 The flowchart of a method for tracking the roll gap in a sector section of a slab under heavy pressure according to an embodiment of the present invention is shown; Figure 2 The proportional relationship between the length of the billet that has been pressed down in the current sector segment and the total length of the billet is shown according to Embodiment 1 of the present invention. Figure 3 The optimal percentage of the thin blank in the current sector segment within the sector segment is shown according to Embodiment 1 of the present invention to ensure the pressing effect. Figure 4 The optimal percentage of the thin blank in the current sector segment is shown in Embodiment 1 of the present invention to ensure the lifespan of the equipment.

[0043] like Figure 1 As shown, the method for tracking the roll gap in a sector under heavy pressure on a slab provided by this invention mainly includes the following steps:

[0044] Step S1: Based on the known billet thickness tracking data, calculate the percentage of thin billets in the current sector segment; whereby the percentage of thin billets in the sector segment is the ratio of the length of the billet that has been pressed down in the current sector segment to the total length of the billet in the current sector segment.

[0045] Specifically, the billet thickness tracking data is known data from the continuous casting process. This data records the process of billet thickness change. Therefore, based on this data, it is possible to understand whether the billet has been pressed down, and the thickness value of the billet after pressing down. In the technical solution of this invention, based on the known billet thickness tracking data, it is possible to understand the length of the billet that has been pressed down, the length of the billet that has not been pressed down, and the total length of the billet in the current sector segment. Thus, it is possible to calculate the ratio of the length of the billet that has been pressed down in the current sector segment to the total length of the billet in the current sector segment, that is, the proportion of thin billets in the current sector segment.

[0046] As a preferred embodiment of the present invention, based on known billet thickness tracking data, the percentage of thin billets in the current sector segment is statistically analyzed, including:

[0047] Based on the known billet thickness tracking data, the length of the billet that has been pressed down in the current sector segment is calculated.

[0048] The percentage of the length of the billet that has been pressed down in the current sector segment to the total length of the billet in the current sector segment is taken as the percentage of the thin billet in the current sector segment.

[0049] Specifically, the steps for calculating the proportion of thin billets in the current sector segment are as follows: First, based on the known billet thickness tracking data, calculate the length of the billet that has been pressed down in the current sector segment and the total length of the billet in the previous sector segment; then calculate the percentage of the length of the billet that has been pressed down in the current sector segment to the total length of the billet in the current sector segment, and thus obtain the proportion of thin billets in the current sector segment.

[0050] Step S2: If the current sector segment is located before the reference position for the billet's no-bulging capability, and the proportion of thin billets in the sector segment meets the preset thin billet proportion condition for ensuring the pressing effect, reset the roll gap value of the current sector segment according to the preset pressing effect strategy; if the current sector segment is located after the reference position for the billet's no-bulging capability, and the proportion of thin billets in the sector segment meets the preset thin billet proportion condition for ensuring the pressing device, reset the roll gap value of the current sector segment according to the preset pressing device strategy, so as to complete the tracking of the roll gap of the sector segment.

[0051] Specifically, the slab heavy-pressure sector roll gap tracking protected by this invention resets or updates the roll gap value of the current sector segment when a suitable time (or when a set condition is met), while the roll gap value of the current sector segment remains unchanged when the set time (or condition) is not met. That is, tracking in this invention means roll gap updating and resetting. If the current sector segment is before the reference position for slab no bulging capability, and the proportion of thin billets in the sector segment meets the preset thin billet proportion condition for ensuring the pressing effect, the roll gap value of the current sector segment is reset according to the preset pressing effect strategy. If the current sector segment is after the reference position for slab no bulging capability, and the proportion of thin billets in the sector segment meets the preset thin billet proportion condition for ensuring the pressing device, the roll gap value of the current sector segment is reset according to the preset pressing device strategy. Outside of the above-mentioned set conditions, the roll gap value of the current sector segment remains unchanged.

[0052] As a preferred embodiment of the present invention, the preset strategy for ensuring the pressing effect is as follows:

[0053] When the proportion of thin billets in the current sector segment is 5%-10%, the roll gap values ​​at the billet inlet and outlet of the current sector segment are reset to the thickness values ​​of the billet that has already been pressed down.

[0054] Specifically, the current sector segment is located before the reference position where the billet has no bulging capacity, meaning the billet is relatively soft. The main focus should be on ensuring the pressing effect. In a preferred embodiment of the present invention, when the proportion of thin billets in the current sector segment is 5%-10%, the roll gap values ​​at the billet inlet and outlet of the current sector segment are reset to the thickness values ​​of the billet that has already been pressed. That is, when the length of the billet that has not been pressed in the current sector segment is relatively long, the roll gap values ​​at the billet inlet of the previous sector segment and the billet outlet of the current sector segment are simultaneously reset to the thickness values ​​of the billet that has already been pressed. At this time, there are more billets in the current sector segment under pressing, which can ensure the pressing effect.

[0055] As a preferred embodiment of the present invention, the preset strategy for ensuring the pressing effect is as follows:

[0056] When the proportion of thin billets in the current sector segment is 5%, the roll gap values ​​at the billet inlet and billet outlet of the current sector segment are reset to the thickness values ​​of the billet that has already been pressed down.

[0057] It should be noted that: before the reference position where the current sector segment is located, when the proportion of thin billet in the current sector segment is 5%, resetting the roll gap values ​​of the billet inlet and the billet outlet of the current sector segment to the thickness value of the billet that has been pressed down is a further preferred embodiment of the present invention, and the present invention does not make any special limitation on this.

[0058] As a preferred embodiment of the present invention, the preset strategy for ensuring the pressing effect is as follows:

[0059] When the proportion of thin billets in the current sector segment is 1%-5%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0060] When the proportion of thin billets in the current sector segment is 40%-60%, the roll gap value at the billet exit of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0061] Specifically, when the current sector segment is located before the reference position where the billet has no bulging capability, i.e. the billet is relatively soft, and the main goal is to ensure the pressing effect, the preset strategy for ensuring the pressing effect can be to reset the roll gap values ​​at both the billet inlet and outlet of the current sector segment simultaneously, or to reset the roll gap values ​​at the billet inlet and outlet of the current sector segment separately. When resetting the roll gap values ​​at the billet inlet and outlet of the current sector segment separately, if the proportion of thin billets in the current sector segment is 1%-5%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed; if the proportion of thin billets in the current sector segment is 40%-60%, the roll gap value at the billet outlet of the current sector segment is reset to the thickness value of the billet that has already been pressed.

[0062] As a preferred embodiment of the present invention, the preset strategy for ensuring the pressing effect is as follows:

[0063] When the proportion of thin billets in the current sector segment is 5%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0064] When the proportion of thin billets in the current sector segment is 50%, the roll gap value at the billet exit of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0065] It should be noted that when resetting the roll gap values ​​at the inlet and outlet of the current sector segment using a preset strategy to ensure the pressing effect, a further preferred embodiment of the present invention is that when the proportion of thin billets in the current sector segment is 5%, the roll gap value at the inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed; when the proportion of thin billets in the current sector segment is 50%, the roll gap value at the outlet of the current sector segment is reset to the thickness value of the billet that has already been pressed. The present invention does not impose any particular limitation on this.

[0066] As a preferred embodiment of the present invention, the preset strategy for ensuring the pressing device is as follows:

[0067] When the proportion of thin billets in the current sector segment is more than 95%, the roll gap values ​​of the billet inlet and the billet outlet of the current sector segment are reset to the thickness values ​​of the billet that has already been pressed down.

[0068] Specifically, the current sector segment is located after the reference position where the billet has no bulging capability, meaning the billet is relatively hard. Therefore, ensuring equipment lifespan is paramount. In a preferred embodiment of the invention, when the proportion of thin billets in the current sector segment is over 95%, the roll gap values ​​at the billet inlet and outlet of the current sector segment are reset to the thickness value of the billet that has already been pressed down. That is, when the length of the billet that has not been pressed down in the current sector segment is short, the roll gap values ​​at the billet inlet of the previous sector segment and the billet outlet of the current sector segment are simultaneously reset to the thickness value of the billet that has already been pressed down. At this time, very few billets are in a pressed state within the current sector segment, resulting in low billet pulling resistance and ensuring equipment lifespan.

[0069] As a preferred embodiment of the present invention, the preset strategy for ensuring the pressing device is as follows:

[0070] When the proportion of thin billets in the current sector segment is 50%-60%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0071] When the proportion of thin billets in the current sector segment is more than 95%, the roll gap value at the billet exit of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0072] Specifically, when the current sector segment is located after the reference position where the billet has no bulging capability, i.e. the billet is relatively hard, and the priority is to ensure equipment lifespan, the preset strategy for ensuring equipment lifespan can be to reset the roll gap values ​​at both the billet inlet and outlet of the current sector segment simultaneously, or to reset the roll gap values ​​at the billet inlet and outlet of the current sector segment separately. When resetting the roll gap values ​​at the billet inlet and outlet of the current sector segment separately, if the proportion of thin billets in the current sector segment is 50%-60%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down; if the proportion of thin billets in the current sector segment is more than 95%, the roll gap value at the billet outlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0073] As a preferred embodiment of the present invention, the preset strategy for ensuring the pressing device is as follows:

[0074] When the proportion of thin billets in the current sector segment is 50%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

[0075] It should be noted that when the roll gap values ​​of the billet inlet and the billet outlet of the current sector segment are reset using a preset equipment life guarantee strategy, a further preferred embodiment of the present invention is that when the proportion of thin billets in the current sector segment is 50%, the roll gap value of the billet inlet of the current sector segment is reset to the thickness value of the billet that has been pressed down. The present invention does not impose any particular limitation on this.

[0076] As a preferred embodiment of the present invention, the reference position for the slab's ability to be free of bulging is the position on the slab where the temperature at the center of the slab is 100°C-200°C lower than the solidus temperature.

[0077] Specifically, the hardness and solidification end of the billet are comprehensively extracted to determine the reference position for the billet's ability to prevent bulging. This reference position refers to the location on the billet where the center temperature is 100℃-200℃ lower than the solidus temperature, calculated using an online model in existing technology. When the sector segment is located before the reference position, ensuring the pressing effect is prioritized; when the sector segment is located after the reference position, ensuring equipment lifespan and smooth production is prioritized.

[0078] Based on known billet thickness tracking data, the ratio of the length of the billet that has already been pressed into the current sector segment to the total length of the billets in the current sector segment is calculated; that is, the percentage of thin billets in the current sector segment is calculated. If the current sector segment is before the reference position where the billet has no bulging capability, and the percentage of thin billets in the sector segment meets the preset thin billet percentage condition for ensuring the pressing effect, then the roll gap value of the current sector segment is reset according to the preset pressing effect strategy. That is, when the billet is relatively soft, the roll gap value of the current sector segment is reset while mainly ensuring the pressing effect of the billet. If the current sector segment is after the reference position where the billet has no bulging capability, and the percentage of thin billets in the sector segment meets the preset thin billet percentage condition for ensuring the pressing effect, then the preset pressing effect strategy is used to reset the roll gap value of the current sector segment. The roll gap value of the current sector segment is reset based on the billet's hardness. Specifically, when the billet is relatively hard, the roll gap value of the current sector segment is reset while prioritizing equipment lifespan. This allows for different strategies to be adopted based on the billet's hardness and the tracking of changes in the billet thickness being pressed. The goal is to ensure higher pressing efficiency when the billet is softer and lower equipment stress when the billet is harder, thus determining the optimal timing for resetting (tracking or updating) the roll gap value of the sector segment. This achieves the technical effect of ensuring the pressing process while simultaneously guaranteeing equipment lifespan and stable production. It effectively improves production stability and efficiency, and reduces production costs.

[0079] To better illustrate the application of the slab heavy-pressure sector roll gap tracking method provided by this invention, the following specific embodiments are provided:

[0080] Example 1

[0081] Taking a 300x1650mm thick plate casting machine in a steel plant as an example, the production speed is 0.5m / min, the calculated solidification end is 18m, the reference position for the billet's no-bulging capability is 20.5m, the reduction sections are sections 9 and 10, section 11 is located before the reference position for the billet's no-bulging capability, and sections 12 to 14 are located after the reference position for the billet's no-bulging capability. Tracking of the roll gap in the fan-shaped section is performed based on known billet thickness tracking data and different strategies. Extreme cases are explained below:

[0082] The billet that has been pressed down becomes thinner, with a reduced thickness, while the billet that has not been pressed down has a larger thickness. There is a thickness step in the billet before and after pressing down. As the casting process continues, this thickness step between the pressed and unpressed billets shifts backward. Figure 2 As shown, when the thickness step is located in a certain sector segment (the current sector segment), the length of the cast billet that has already been pressed is a certain proportion of the total length of the cast billets in the current sector segment. This proportion can be defined as the thin billet ratio of the sector segment. The larger the proportion of the thin billet ratio of the sector segment, the longer the length of the cast billet that has already been pressed in the current sector segment. Figure 2 As can be seen, the proportion of thin billets in the current sector segment is greater than 50%. Obviously, the smaller the proportion of thin billets in the sector segment, the more billets will be in the pressing state when the roll gap values ​​of the billet inlet and billet outlet of the current sector segment are simultaneously tracked (reset or updated) to the thickness value of the billet that has been pressed. This is beneficial to the pressing effect, but at the same time, the pressing force required is large, which is not good for the equipment life and the billet pulling resistance is also greater.

[0083] The optimal situation to ensure the compression effect, such as Figure 3 As shown, this is the case where the proportion of thin billets in the current sector segment is relatively small, such as 5%. That is, when the billet that has already been pressed enters the current sector segment, the roll gap values ​​of the billet inlet and outlet of the current sector segment are simultaneously tracked to the thickness value of the billet that has already been pressed. At this time, the entire billet in the current sector segment is equivalent to being pressed, which is beneficial to ensure the pressing process effect. However, it is obvious that the equipment is subjected to the greatest force and the billet pulling resistance is also the greatest.

[0084] The optimal way to ensure equipment lifespan, such as... Figure 4As shown, this is the case where the thin billet accounts for the largest proportion of the current sector segment. For example, if the thin billet accounts for more than 95% of the sector segment, that is, the billet that has been pressed out is about to leave the current sector segment. Only then will the roll gap values ​​of the billet inlet and outlet of the current sector segment be simultaneously tracked (reset or updated) to the thickness value of the billet that has been pressed out. At this time, during the process of the roll gap of the previous sector segment becoming smaller (similar to pressing), there is basically no resistance from the billet, the required force is minimal, which is beneficial to the life of the equipment. However, the billet that has been pressed out is not compressed for a long distance within the current sector segment, and there is a possibility of bulging, which cannot guarantee the pressing effect.

[0085] Here, the fan-shaped section roll gap tracking is simplified to simultaneous tracking of the roll gap values ​​at the billet inlet and outlet. In practice, the roll gaps at the billet inlet and outlet can also be tracked separately. The principle is the same as the simultaneous tracking mentioned above. That is, when the proportion of thin billets in the fan-shaped section is smaller, the roll gap tracking is performed to obtain the thickness value of the billet that has already been pressed down, which is beneficial for pressing down the billet but requires greater equipment force. When the proportion of thin billets in the fan-shaped section is larger, the roll gap tracking is performed to obtain the thickness value of the billet that has already been pressed down, the equipment force is smaller, but the unpressed length of the billet is reduced.

[0086] Specifically, in this embodiment, segment 11 is located before the reference position for no bulging of the cast billet, primarily to ensure the pressing effect. It is set so that when the proportion of thin billets in the fan-shaped segment is 5%, the roll gap value at the inlet of the current fan-shaped segment tracks the thickness of the already pressed billet; when the proportion of thin billets in the fan-shaped segment is 50%, the roll gap value at the outlet of the current fan-shaped segment tracks the thickness of the already pressed billet. Segments 12 to 14 are located after the reference position for no bulging of the cast billet, primarily to ensure equipment lifespan and smooth billet pulling. It is set so that when the proportion of thin billets in the fan-shaped segment is 50%, the roll gap value at the inlet of the current fan-shaped segment tracks the thickness of the already pressed billet; when the proportion of thin billets in the fan-shaped segment is above 95%, the roll gap value at the outlet of the current fan-shaped segment tracks the thickness of the already pressed billet. The above overall settings can achieve a comprehensive effect of optimizing process efficiency, equipment lifespan, and smooth billet pulling.

[0087] As can be seen from the above specific embodiments, the slab heavy-pressure sector roll gap tracking method provided by the present invention, based on known slab thickness tracking data, calculates the ratio of the length of the slab that has been pressed into the current sector to the total length of the slab in the current sector, i.e., calculates the proportion of thin slabs in the current sector. If the current sector is before the reference position where the slab has no bulging capability, and the proportion of thin slabs in the sector meets the preset thin slab proportion condition to ensure the pressing effect, then the roll gap value of the current sector is reset according to the preset pressing effect strategy. That is, when the slab is relatively soft, the roll gap value of the current sector is reset while mainly ensuring the pressing effect on the slab. If the current sector is after the reference position where the slab has no bulging capability, and the proportion of thin slabs in the sector meets the preset guarantee... The thin billet ratio condition of the pressing equipment is used to reset the roll gap value of the current sector segment according to the preset pressing equipment strategy. That is, when the billet is relatively hard, the roll gap value of the current sector segment is reset while ensuring the equipment life. This achieves the reset of the roll gap of the current sector segment based on the hardness of the billet and the tracking of the change in the thickness of the billet being pressed. Different strategies are adopted to ensure the pressing effect of the billet and to ensure the equipment life. This achieves the goal of ensuring more pressing when the billet is soft and minimizing the stress on the equipment when the billet is hard. In other words, it determines the most appropriate time to reset (track or update) the roll gap value of the sector segment, thereby achieving the technical effect of ensuring the pressing process, while also ensuring the equipment life and stable production. This can effectively improve the stability and efficiency of production and reduce production costs.

[0088] The method for tracking the roll gap in a sector 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 the roll gap in a sector 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 roll gap in a sector-shaped section of a slab under heavy pressure, characterized in that, Includes the following steps: Based on the known billet thickness tracking data, the percentage of thin billets in the current sector segment is calculated; wherein, the percentage of thin billets in the sector segment is the ratio of the length of the billet that has been pressed down in the current sector segment to the total length of the billets in the current sector segment. If the current sector segment is located before the reference position for no bulging capability of the cast billet, and the proportion of thin billet in the sector segment meets the preset thin billet proportion condition for ensuring the pressing effect, the roll gap value of the current sector segment is reset according to the preset pressing effect guarantee strategy; if the current sector segment is located after the reference position for no bulging capability of the cast billet, and the proportion of thin billet in the sector segment meets the preset thin billet proportion condition for ensuring the pressing device, the roll gap value of the current sector segment is reset according to the preset pressing device guarantee strategy, so as to complete the tracking of the roll gap of the sector segment; wherein, The preset strategy to ensure the compression effect is as follows: When the proportion of thin billets in the current sector segment is 5%-10%, the roll gap values ​​at the billet inlet and outlet of the current sector segment are reset to the thickness values ​​of the billet that has already been pressed down; or, When the proportion of thin billets in the current sector segment is 1%-5%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down; when the proportion of thin billets in the current sector segment is 40%-60%, the roll gap value at the billet outlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down. The preset strategy for ensuring the pressure reduction device is as follows: When the proportion of thin billets in the current sector segment is 95% or more, the roll gap values ​​at the billet inlet and outlet of the current sector segment are reset to the thickness values ​​of the billet that has already been pressed down; or, When the proportion of thin billets in the current sector segment is 50%-60%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down; when the proportion of thin billets in the current sector segment is 95% or more, the roll gap value at the billet outlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

2. The method for tracking the roll gap in a sector under heavy pressure on a slab according to claim 1, characterized in that, The step of calculating the proportion of thin billets in the current sector segment based on known billet thickness tracking data includes: Based on the known billet thickness tracking data, the length of the billet that has been pressed down in the current sector segment is calculated. The percentage of the length of the billet that has been pressed down in the current sector segment to the total length of the billet in the current sector segment is taken as the percentage of the thin billet in the current sector segment.

3. The method for tracking the roll gap in a sector under heavy pressure on a slab according to claim 1, characterized in that, The preset strategy to ensure the compression effect is as follows: When the proportion of thin billets in the current sector segment is 5%, the roll gap values ​​of the billet inlet and the billet outlet of the current sector segment are reset to the thickness value of the billet that has been pressed down.

4. The method for tracking the roll gap in a sector under heavy pressure on a slab according to claim 1, characterized in that, The preset strategy to ensure the compression effect is as follows: When the proportion of thin billets in the current sector segment is 5%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has been pressed down. When the proportion of thin billets in the current sector segment is 50%, the roll gap value at the billet exit of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

5. The method for tracking the roll gap in a sector under heavy pressure on a slab according to claim 1, characterized in that, The preset strategy for ensuring the pressure reduction device is as follows: When the proportion of thin billets in the current sector segment is 50%, the roll gap value at the billet inlet of the current sector segment is reset to the thickness value of the billet that has already been pressed down.

6. The method for tracking the roll gap in a sector under heavy pressure on a slab according to claim 1, characterized in that, The reference position for the non-bulging ability of the cast billet is the position on the cast billet where the center temperature of the cast billet is 100℃-200℃ lower than the solidus temperature.

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