A slab continuous casting process parameter control method

Abstract

This application discloses a parameter control method for slab continuous casting, relating to the field of steelmaking continuous casting technology. The method includes: conducting parameter control experiments in the slab steelmaking continuous casting process; determining the range of process parameters based on the experimental results; and setting process parameters for summer and winter modes according to the season. This application, by specifically adjusting key process parameters in the continuous casting process, first determines the root cause of slab side cracking through experimental analysis, and then sets the casting speed, crystallizer narrow-face cooling water volume, secondary cooling water specific volume, and straightening temperature for summer and winter modes respectively, based on temperature changes in different seasons. Through this series of precise controls, the grain structure on the slab side is effectively refined, avoiding cracking problems caused by coarse grains during rolling. After implementation of this application, side cracking and edge damage in the produced ultra-thick steel plates completely disappear, significantly improving the appearance quality and yield of the steel plates, while ensuring the stability of production rhythm and contract delivery.

Description

Technical Field

[0001] This application relates to the field of steelmaking continuous casting technology, and in particular to a method for controlling process parameters in slab continuous casting. Background Technology

[0002] In the steel metallurgical industry, continuous casting is a crucial process for continuously casting molten steel into solid steel billets, providing raw materials for subsequent rolling into various steel products. Thick billets produced by slab continuous casting machines undergo heating and rolling processes to become ultra-thick steel plates with a thickness of 80 mm or more. These ultra-thick steel plates are widely used in high-rise buildings, large bridges, heavy machinery, and other fields with high load-bearing requirements. To improve the appearance quality and material utilization rate of the steel plates, high-end users typically require the steel plates to be delivered with four rough edges, meaning that none of the four sides of the steel plate have undergone flame trimming; they are delivered directly in the rolled state. This necessitates that the sides of the steel plate be smooth and defect-free after rolling.

[0003] Under current technological conditions, when producing ultra-thick steel plates, if there are minor defects in the internal and surface quality of the billet, especially uneven microstructure or microcracks on the side of the billet, these defects are easily expanded and extended after high compression ratio rolling, eventually leading to severe cracking or even edge damage on the side of the finished steel plate. This defect not only destroys the integrity of the steel plate, making it unable to meet the stringent requirement of four-edge roughness during delivery, but also necessitates trimming and finishing after rolling, resulting in decreased metal yield, extended production processes, and delayed contract delivery, causing significant economic losses to enterprises. Although the industry recognizes the impact of billet quality on the final product, the root cause of the unique side cracking problem that occurs after rolling in ultra-thick steel plates is often difficult to pinpoint accurately. It is usually attributed broadly to billet problems, rolling procedures, or heating regimes, leading to a long-term lack of stable and effective preventative measures. This results in recurring problems, hindering the stable improvement of product quality and the expansion into high-end customers. Summary of the Invention

[0004] In view of this, this application provides a method for controlling parameters in the continuous casting process of slabs, the main purpose of which is to solve the technical problem that the steel plates in the traditional casting production process have serious cracks or even broken edges and cannot be delivered with four rough edges.

[0005] This application provides a method for controlling parameters in the slab continuous casting process, including: Parameter control experiments were conducted in the slab steelmaking continuous casting process. Determine the range of process parameters based on experimental results; The process parameters are set according to the season, with summer mode and winter mode.

[0006] In one feasible implementation, the step of conducting parameter control experiments in the slab steelmaking continuous casting process includes: Control the pulling speed within the preset range; Increase the cooling water flow rate and foot roller water flow rate on the narrow face of the crystallizer; The samples were sampled and compared in different areas.

[0007] In one feasible implementation, the pulling speed within the preset range is 0.72-0.76 m / min.

[0008] In one feasible implementation, the step of increasing the cooling water volume on the narrow face of the crystallizer includes: When the pulling speed is 0.72 m / min, the water flow rate of the narrow face of the crystallizer is set to 730 L / min; When the pulling speed is 0.76 m / min, the water flow rate of the narrow face of the crystallizer is set to 780 L / min.

[0009] In one feasible implementation, the step of setting the process parameters for summer and winter modes according to the seasons includes: The summer and winter modes are distinguished based on seasonal temperature changes; Process parameters are controlled separately; The specific water volume of the secondary cooling water and the straightening temperature are obtained based on the process parameters of summer mode and winter mode.

[0010] In one feasible implementation, the process parameters of the summer mode include: The following settings were set: pulling speed 0.72 m / min, water flow rate on the narrow face of the crystallizer 730 L / min, water flow rate on the inner arc of the wide face of the crystallizer 3800 L / min, water flow rate on the outer arc 4000 L / min, water flow rate on the foot roller of the narrow face 160 L / min, secondary cooling water ratio 0.50 L / kg, and straightening temperature 950℃.

[0011] In one feasible implementation, the process parameters for the summer mode further include: The following settings were set: pulling speed 0.76 m / min, water flow rate on the narrow face of the crystallizer 780 L / min, water flow rate on the inner arc of the wide face of the crystallizer 4500 L / min, water flow rate on the outer arc 4500 L / min, water flow rate on the foot roller of the narrow face 190 L / min, secondary cooling water ratio 0.50 L / kg, and straightening temperature 950℃.

[0012] In one feasible implementation, the process parameters for the winter mode include: The following settings were set: pulling speed 0.72 m / min, water flow rate on the narrow face of the crystallizer 730 L / min, water flow rate on the inner arc of the wide face of the crystallizer 3800 L / min, water flow rate on the outer arc 4000 L / min, water flow rate on the foot roller of the narrow face 150 L / min, secondary cooling water ratio 0.46 L / kg, and straightening temperature 960℃.

[0013] In one feasible implementation, the process parameters for the winter mode further include: The following settings were set: pulling speed 0.76 m / min, water flow rate on the narrow face of the crystallizer 780 L / min, water flow rate on the inner arc of the wide face of the crystallizer 4500 L / min, water flow rate on the outer arc 4500 L / min, water flow rate on the foot roller of the narrow face 180 L / min, secondary cooling water ratio 0.46 L / kg, and straightening temperature 960℃.

[0014] In one feasible implementation, the method further includes: The crystallizer is controlled in summer and winter modes according to the preset crystallizer vibration parameter table. The crystallizer taper is 1.1%.

[0015] This application provides a method for controlling parameters in the slab continuous casting process, including: conducting parameter control experiments in the slab steelmaking continuous casting process; determining the range of process parameters based on the experimental results; and setting process parameters for summer and winter modes according to the season. This application, by specifically adjusting key process parameters in the continuous casting process, first determines the root cause of slab side cracking through experimental analysis, and then sets the casting speed, crystallizer narrow-face cooling water volume, secondary cooling water specific volume, and straightening temperature for summer and winter modes respectively, based on temperature changes in different seasons. Through this series of precise controls, the grain structure on the slab side is effectively refined, avoiding cracking problems caused by coarse grains during rolling. After implementation of this application, side cracking and edge defects in the produced ultra-thick steel plates completely disappear, and the edge quality is smooth and aesthetically pleasing, eliminating the need for flame trimming. This allows for direct delivery in a four-rough-edge state, significantly improving the appearance quality and yield of the steel plates, while ensuring the stability of production rhythm and contract delivery.

[0016] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0017] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A flowchart illustrating a method for controlling parameters in a slab continuous casting process according to an embodiment of this application is shown. Figure 2 This illustration shows a flowchart of a parameter control experiment in the slab steelmaking continuous casting process provided in an embodiment of this application. Detailed Implementation

[0019] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0021] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] See Figure 1 The diagram illustrates a flow chart of a slab continuous casting process parameter control method provided in an embodiment of this application, including: Parameter control experiments were conducted in the slab steelmaking continuous casting process. Determine the range of process parameters based on experimental results; The process parameters are set according to the season, with summer mode and winter mode.

[0023] In the above embodiments, parameter control experiments were first conducted in the continuous casting process. By adjusting key variables such as casting speed and cooling water volume, and by sampling and comparing different areas of the cast billet, the microstructure of the narrow face and edges of the billet was systematically observed using pickling and scanning electron microscopy analysis. This allowed for a precise identification of the root cause of side cracking in the steel plate as coarse grains on the narrow face of the billet. Based on this, the range of process parameters that could effectively refine the grains was determined according to the experimental results. Furthermore, based on seasonal temperature changes, the process parameters were divided into summer and winter modes for separate setting to achieve stable control throughout the year.

[0024] This application employs an experimental approach, shifting the root cause of the problem from the traditional rolling process to the continuous casting process, thus avoiding the blindness of empirical adjustments. Based on this, process parameters are set according to the season, adapting to the objective law of cooling water temperature changing with ambient temperature. This ensures that the cooling intensity and straightening temperature of the billet remain within a stable and controllable range in different seasons, thereby providing high-quality billets with uniform structure and no surface defects for subsequent rolling, eliminating the conditions for lateral cracking at its source.

[0025] See Figure 2 This document illustrates a flowchart of a parameter control experiment conducted in the slab steelmaking continuous casting process, as provided in an embodiment of this application. Further, the steps for conducting the parameter control experiment in the slab steelmaking continuous casting process include: Control the pulling speed within the preset range; Increase the cooling water flow rate and foot roller water flow rate on the narrow face of the crystallizer; The samples were sampled and compared in different areas.

[0026] In the above embodiments, during the parameter control experiment, the continuous casting speed was first stabilized within a preset range to avoid adverse effects of speed fluctuations on the solidification structure of the billet. Based on this, the cooling water volume on the narrow face of the crystallizer and the water volume in the foot rollers were appropriately increased to enhance the primary cooling intensity in the narrow face region, promote rapid nucleation of the chilled layer, and inhibit coarse dendrite growth. Subsequently, the billet samples were sampled and compared in different areas, from the edge to the interior of the billet, and then subjected to pickling and scanning electron microscopy analysis. By comparing the microstructure differences in different areas, the correlation between the grain refinement degree of the narrow face and the cooling process was confirmed.

[0027] Through the above steps, the experimental process is no longer a general observation of surface defects, but rather a complete closed loop from process adjustment to microstructure verification. Maintaining the casting speed within a reasonable range ensures the uniformity of the billet solidification process; increasing the cooling water volume in the narrow face directly addresses the root cause of coarse grains in the narrow face by strengthening cooling; and comparative sampling of different areas provides a visual basis for microstructure analysis, accurately verifying the effects of process adjustments and providing reliable technical support for parameter setting in subsequent large-scale production.

[0028] Furthermore, the preset pulling speed is 0.72-0.76 m / min.

[0029] In the above embodiments, during the continuous casting process, the casting speed is stably controlled within a preset range of 0.72-0.76 m / min. This casting speed range was determined during the experimental phase by comparing the microstructure of the narrow face of the billet under different casting speed conditions. This ensures both the production efficiency of the continuous casting process and provides sufficient residence time for the cooling of the crystallizer, allowing the solidified shell to grow uniformly and avoiding excessively thin billet shells or uneven cooling due to excessively high casting speeds.

[0030] The selection of this casting speed range ensures production stability while providing a stable process basis for optimizing the cooling water volume in the narrow face. Matching the casting speed with the cooling intensity makes the solidification process of the billet in the crystallizer more stable, and the microstructure of the narrow face is made more uniform and refined. This reduces the risk of cracking caused by coarse grains from the solidification source and provides a dense billet for subsequent rolling.

[0031] Further steps to increase the cooling water flow rate on the narrow face of the crystallizer include: When the pulling speed is 0.72 m / min, the water flow rate of the narrow face of the crystallizer is set to 730 L / min; When the pulling speed is 0.76 m / min, the water flow rate of the narrow face of the crystallizer is set to 780 L / min.

[0032] In the above embodiments, during the process of increasing the cooling water volume of the narrow face of the crystallizer, an appropriate water volume is set according to different drawing speeds. When the drawing speed is 0.72 m / min, the water volume of the narrow face of the crystallizer is set to 730 L / min to meet the cooling requirements of the narrow face area at this drawing speed. When the drawing speed is increased to 0.76 m / min, due to the increased steel flow rate and shortened solidification shell formation time, the water volume of the narrow face is correspondingly increased to 780 L / min to match stronger cooling requirements.

[0033] This application differentiates the amount of water applied to the narrow face based on changes in drawing speed, achieving a dynamic match between cooling intensity and drawing speed. Increasing the amount of water applied to the narrow face at higher drawing speeds can compensate for the shortened cooling time caused by the increased drawing speed, ensuring that the thickness of the chilled layer and the microstructure refinement effect of the narrow face remain stable. This avoids the problem of insufficient or excessive cooling caused by drawing speed adjustments, enabling the acquisition of a grain-refined narrow face microstructure under different drawing speed conditions.

[0034] Furthermore, the steps for setting process parameters for summer and winter modes according to the seasons include: The summer and winter modes are distinguished based on seasonal temperature changes; Process parameters are controlled separately; The specific water volume of the secondary cooling water and the straightening temperature are obtained based on the process parameters of summer mode and winter mode.

[0035] In the above embodiments, considering the impact of ambient temperature on the continuous casting cooling water temperature, the entire year is divided into two operating conditions: summer mode and winter mode. In summer mode, the cooling water inlet temperature is higher, resulting in relatively unfavorable heat dissipation conditions; in winter mode, the cooling water inlet temperature is lower, leading to relatively enhanced cooling capacity. Based on this difference, key process parameters such as the crystallizer cooling water flow rate, the secondary cooling zone specific water flow rate, and the straightening temperature are set independently. Corresponding control targets for the secondary cooling water specific water flow rate and straightening temperature are obtained according to different modes, achieving refined seasonal control.

[0036] This scheme fully considers the objective physical law of cooling water temperature changing with ambient temperature, avoiding the cooling intensity mismatch problem caused by using uniform parameters throughout the year. By distinguishing between summer and winter modes, the billet can obtain a suitable cooling effect in both extreme environments. This prevents coarse grains caused by insufficient cooling capacity in summer, and avoids straightening transverse cracks caused by excessive cooling in winter, ensuring the consistency of billet quality throughout the year.

[0037] Furthermore, the process parameters for the summer mode include: The following settings were set: pulling speed 0.72 m / min, water flow rate on the narrow face of the crystallizer 730 L / min, water flow rate on the inner arc of the wide face of the crystallizer 3800 L / min, water flow rate on the outer arc 4000 L / min, water flow rate on the foot roller of the narrow face 160 L / min, secondary cooling water ratio 0.50 L / kg, and straightening temperature 950℃.

[0038] In the above embodiment, under summer mode, when the casting speed is 0.72 m / min, the water flow rate on the narrow face of the crystallizer is set to 730 L / min, the water flow rates on the inner and outer arcs of the wide face of the crystallizer are set to 3800 L / min and 4000 L / min respectively, and the water flow rate on the narrow face foot rollers is set to 160 L / min. The specific water flow rate in the secondary cooling zone is set to 0.50 L / kg, and the straightening temperature is controlled at 950℃. Through this combination of parameters, even under the condition of high cooling water temperature in summer, sufficient cooling intensity can still be ensured on the narrow face of the cast billet. Simultaneously, by controlling the specific water flow rate in the secondary cooling zone and the straightening temperature, transverse cracks caused by excessively low temperatures in the straightening zone are avoided.

[0039] This set of summer mode parameters compensates for the weakened cooling effect caused by the increased cooling water temperature by increasing the cooling water volume in the narrow face and the water volume in the foot rolls, allowing the grains of the quenched layer in the narrow face to remain refined even in the high-temperature season. At the same time, by controlling the secondary cooling water volume and the straightening temperature, a balance is achieved between strengthening cooling and preventing straightening cracks, so that the billet can also obtain a quality state with uniform structure and good surface even in the high-temperature environment of summer.

[0040] Furthermore, the process parameters for the summer mode also include: The following settings were set: pulling speed 0.76 m / min, water flow rate on the narrow face of the crystallizer 780 L / min, water flow rate on the inner arc of the wide face of the crystallizer 4500 L / min, water flow rate on the outer arc 4500 L / min, water flow rate on the foot roller of the narrow face 190 L / min, secondary cooling water ratio 0.50 L / kg, and straightening temperature 950℃.

[0041] In the above embodiments, under summer mode, when the drawing speed is increased to 0.76 m / min, the water flow rate on the narrow face of the crystallizer is correspondingly increased to 780 L / min, the water flow rate on the inner and outer arcs of the wide face of the crystallizer is increased to 4500 L / min, and the water flow rate on the narrow face foot rollers is increased to 190 L / min. The water flow rate in the secondary cooling zone is maintained at 0.50 L / kg, and the straightening temperature is still controlled at 950℃. This set of parameters forms a stepped match with the lower drawing speed settings, ensuring that the cooling intensity of the narrow face is simultaneously enhanced at higher drawing speeds.

[0042] This solution, implemented under high-speed summer production conditions, ensures a coordinated match between cooling intensity and casting speed by simultaneously increasing the water volume in the narrow face, wide face, and foot rolls. The higher water volume in the narrow face effectively suppresses the grain coarsening tendency that may result from increased casting speed, allowing the narrow face of the billet to still obtain a fine chilled layer structure during rapid solidification. This maintains the quality of the billet's side surface while ensuring production efficiency, providing a reliable raw material guarantee for subsequent rolling.

[0043] Furthermore, the process parameters for the winter mode include: The following settings were set: pulling speed 0.72 m / min, water flow rate on the narrow face of the crystallizer 730 L / min, water flow rate on the inner arc of the wide face of the crystallizer 3800 L / min, water flow rate on the outer arc 4000 L / min, water flow rate on the foot roller of the narrow face 150 L / min, secondary cooling water ratio 0.46 L / kg, and straightening temperature 960℃.

[0044] In the above embodiment, under winter mode, when the pulling speed is 0.72 m / min, the water flow rate on the narrow face of the crystallizer is set to 730 L / min, the water flow rates on the inner and outer arcs of the wide face of the crystallizer are set to 3800 L / min and 4000 L / min respectively, and the water flow rate on the narrow face foot roller is set to 150 L / min. Since the cooling water temperature is lower in winter and the cooling capacity is naturally stronger, the specific water flow rate in the secondary cooling zone is appropriately reduced to 0.46 L / kg, and the straightening temperature is correspondingly increased to 960℃ to avoid the straightening zone temperature from being too low.

[0045] The parameters for this winter mode fully consider the enhanced cooling effect brought by low-temperature cooling water. While ensuring the refinement of the narrow face grains, the cooling intensity of the secondary cooling zone is appropriately reduced and the straightening temperature is increased. This adjustment not only utilizes the favorable condition of low water temperature in winter to ensure the refinement of the narrow face structure, but also effectively prevents the generation of transverse cracks in the straightening process due to excessive cooling, making the quality of the cast billet more stable and reliable under winter production conditions.

[0046] Furthermore, the process parameters for the winter mode also include: The following settings were set: pulling speed 0.76 m / min, water flow rate on the narrow face of the crystallizer 780 L / min, water flow rate on the inner arc of the wide face of the crystallizer 4500 L / min, water flow rate on the outer arc 4500 L / min, water flow rate on the foot roller of the narrow face 180 L / min, secondary cooling water ratio 0.46 L / kg, and straightening temperature 960℃.

[0047] In the above embodiment, in winter mode, when the pulling speed is increased to 0.76 m / min, the water flow rate on the narrow face of the crystallizer is correspondingly increased to 780 L / min, the water flow rate on the inner and outer arcs of the wide face of the crystallizer is set to 4500 L / min, and the water flow rate on the narrow face foot rollers is set to 180 L / min. The water flow rate in the secondary cooling zone is maintained at 0.46 L / kg, and the straightening temperature is controlled at 960℃.

[0048] This scheme, during high-speed production in winter, ensures a refined chilling layer by increasing the water volume in both the narrow and wide face sections, while preventing transverse cracks caused by over-cooling by appropriately reducing the secondary chilling water ratio and increasing the straightening temperature. This refined parameter matching allows high-speed cast billets under winter production conditions to balance the refinement of the microstructure in the narrow face section with the surface quality of the straightening zone, further improving the overall quality of the cast billet.

[0049] Furthermore, the methods also include: The crystallizer is controlled in summer and winter modes according to the preset crystallizer vibration parameter table. The crystallizer taper is 1.1%.

[0050] In the above embodiments, in both summer and winter modes, the vibration of the crystallizer is controlled according to a preset crystallizer vibration parameter table. This vibration parameter table includes key parameters such as the matching relationship between amplitude and pulling speed, vibration frequency, negative slip factor, and non-sinusoidal factor. At the same time, the crystallizer taper is set to 1.1% to ensure that the shape of the crystallizer cavity matches the solidification shrinkage, reduce air gaps, and enhance the cooling effect.

[0051] This application provides a stable crystallizer operating condition for both summer and winter modes through a unified vibration parameter table and crystallizer taper setting. Appropriate vibration parameters help improve demolding efficiency and billet surface quality, while a suitable crystallizer taper ensures good contact between the cooling water and the solidified shell, enhancing the uniformity of cooling across narrow facets. This control measure, in conjunction with seasonal cooling parameters, works synergistically to ensure the refinement of the microstructure and the stability of the surface quality of the billet across narrow facets.

[0052] The preset crystallizer vibration parameters are as follows:

[0053] Specifically, the parameters are set as follows: zero-speed amplitude C1 is 2.5 mm, amplitude / speed factor C2 is 3.5 mm / (m / min), zero-speed frequency C3 is 165 C / min, frequency / speed factor C4 is -15 C / min (m / min), negative slip factor C5 is 0, non-sinusoidal factor C6 is 0.6, crystallizer vibration amplitude S is 5.3 mm, crystallizer vibration frequency f is 153, and crystallizer taper is set to 1.1%.

[0054] In specific applications, this application can also be applied according to the following process parameters: When the summer pulling speed is set to 0.72 m / min, the water flow rate on the narrow face of the crystallizer is 730 L / min, the water flow rate on the inner and outer arcs of the wide face of the crystallizer is set to 3800 / 4000 L / min, the water flow rate on the O1N is set to 160 L / min, the water flow rate on the edges of zones 2 / 3 / 4 is set to 50 / 50 / 35 L, the water flow rate on the edges of zone 8 in the straightening section is closed, the crystallizer taper is 1.1%, the crystallizer vibration gauge is No. 5, the secondary cooling water is S_AMedCTest2_360 (950℃), and the specific water flow rate is 0.50 L / kg.

[0055] When the summer casting speed is set to 0.76 m / min, the water flow rate of the crystallizer (both inner and outer arcs) is 4500 L / min. The water flow rate for the narrow face of the crystallizer is 780 L / min, the water flow rate for O1N (narrow face foot roller) is set at 190 L / min, the water flow rate for O1W (wide face foot roller) is set at 1.1 times that of the second stage, the water flow rate for the edges of the bending sections 2 / 3 / 4 is 55 / 55 / 35 L / min, the water flow rate for the edges of the straightening section 8 is turned off, the crystallizer taper is 1.1%, the crystallizer vibration gauge is No. 5, the secondary cooling water is S_AMedCTest2_360 (straightening temperature 950℃), and the specific water flow rate is 0.50 L / kg.

[0056] In winter, at a continuous casting speed of 0.72 m / min, the water flow rate in the crystallizer is 3800 / 4000 L / min for the inner and outer arcs of the wide face, 730 L / min for the narrow face, and 50 / 45 / 35 L / min for zones 2-4 of the bending section. The secondary cooling and straightening temperature is produced according to (960℃) S_AMedCTest4_360. The secondary cooling water flow rate is 0.46 L / kg. The foot roller water flow rate is 1 N to 150 L / min. The water is shut off at the edge of zone 8 of the straightening section. The taper is 1.1%. Vibration gauge is No. 5.

[0057] In winter, at a continuous casting speed of 0.76 m / min, the secondary cooling straightening temperature is produced according to (960℃) S_AMedCTest4_360, the specific water volume is 0.46 L / kg, the water volume of the crystallizer foot roller is 1N 180 L / min, the water volume of the wide face of the crystallizer is 4500 L / min for the inner and outer arcs, the water volume of the narrow face is 780 L / min, the water volume of the bending section in zones 2-4 is 50 / 50 / 35 L / min, the water is shut off at the edge of zone 8 in the straightening section, the taper is 1.1%, and the vibration gauge is No. 5.

[0058] This application provides a schematic diagram of a method for controlling parameters in a slab continuous casting process, which includes: conducting parameter control experiments in the slab steelmaking continuous casting process; determining the range of process parameters based on the experimental results; and setting process parameters for summer and winter modes according to the seasons.

[0059] This application addresses the issue by specifically adjusting key process parameters in the continuous casting process. First, through experimental analysis, the root cause of side cracking in the billet is identified. Then, based on seasonal temperature variations, the casting speed, the cooling water volume on the narrow face of the crystallizer, the specific water volume of the secondary cooling water, and the straightening temperature are set for summer and winter modes respectively. This series of precise controls effectively refines the grain structure on the billet side, preventing cracking problems caused by coarse grains during rolling. After implementation, side cracking and edge defects in the produced ultra-thick steel plates completely disappear, resulting in smooth and aesthetically pleasing edges. Flame trimming is no longer required, enabling direct delivery with four rough edges, significantly improving the appearance quality and yield of the steel plates, while ensuring the stability of production schedule and contract delivery.

[0060] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of a preferred embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing this application. Those skilled in the art will understand that the modules in the apparatus of the embodiment can be distributed within the apparatus of the embodiment as described, or can be modified to be located in one or more apparatuses different from this embodiment. The modules of the above-described embodiment can be combined into one module, or further divided into multiple sub-modules.

[0061] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. A method for controlling parameters in a slab continuous casting process, characterized in that, include: Parameter control experiments were conducted in the slab steelmaking and continuous casting process. Determine the range of process parameters based on experimental results; The process parameters are set according to the season, with summer mode and winter mode.

2. The method according to claim 1, characterized in that, The steps for conducting parameter control experiments in the slab steelmaking continuous casting process include: Control the pulling speed within the preset range; Increase the cooling water flow rate and foot roller water flow rate on the narrow face of the crystallizer; The samples were sampled and compared in different areas.

3. The method according to claim 2, characterized in that, The pulling speed within the preset range is 0.72-0.76 m / min.

4. The method according to claim 2, characterized in that, The step of increasing the cooling water volume on the narrow face of the crystallizer includes: When the pulling speed is 0.72 m / min, the water flow rate of the narrow face of the crystallizer is set to 730 L / min; When the pulling speed is 0.76 m / min, the water flow rate of the narrow face of the crystallizer is set to 780 L / min.

5. The method according to claim 1, characterized in that, The steps for setting the process parameters for summer and winter modes according to the seasons include: The summer and winter modes are distinguished based on seasonal temperature changes; Control process parameters separately; The specific water volume of the secondary cooling water and the straightening temperature are obtained based on the process parameters of summer mode and winter mode.

6. The method according to claim 5, characterized in that, The process parameters for the summer mode include: The following settings were set: pulling speed 0.72 m / min, water flow rate on the narrow face of the crystallizer 730 L / min, water flow rate on the inner arc of the wide face of the crystallizer 3800 L / min, water flow rate on the outer arc 4000 L / min, water flow rate on the foot roller of the narrow face 160 L / min, secondary cooling water ratio 0.50 L / kg, and straightening temperature 950℃.

7. The method according to claim 5, characterized in that, The process parameters for the summer mode also include: The following settings were set: pulling speed 0.76 m / min, water flow rate on the narrow face of the crystallizer 780 L / min, water flow rate on the inner arc of the wide face of the crystallizer 4500 L / min, water flow rate on the outer arc 4500 L / min, water flow rate on the foot roller of the narrow face 190 L / min, secondary cooling water ratio 0.50 L / kg, and straightening temperature 950℃.

8. The method according to claim 5, characterized in that, The process parameters for the winter mode include: The following settings were set: pulling speed 0.72 m / min, water flow rate on the narrow face of the crystallizer 730 L / min, water flow rate on the inner arc of the wide face of the crystallizer 3800 L / min, water flow rate on the outer arc 4000 L / min, water flow rate on the foot roller of the narrow face 150 L / min, secondary cooling water ratio 0.46 L / kg, and straightening temperature 960℃.

9. The method according to claim 5, characterized in that, The process parameters for the winter mode also include: The following settings were set: pulling speed 0.76 m / min, water flow rate on the narrow face of the crystallizer 780 L / min, water flow rate on the inner arc of the wide face of the crystallizer 4500 L / min, water flow rate on the outer arc 4500 L / min, water flow rate on the foot roller of the narrow face 180 L / min, secondary cooling water ratio 0.46 L / kg, and straightening temperature 960℃.

10. The method according to claim 1, characterized in that, The method further includes: The crystallizer is controlled in summer and winter modes according to the preset crystallizer vibration parameter table. The crystallizer taper is 1.1%.

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