Method and apparatus for hot rolling ultra-low carbon steel

Abstract

This invention discloses a hot-rolling production method and apparatus for ultra-low carbon steel. The method includes smelting and continuously casting ultra-low carbon steel to obtain a slab, conveying the slab to a heating furnace for heating, and then sending it to an induction heating device in front of the rolling mill to obtain the edge and core temperatures of the slab. Based on these temperatures, the power of the induction heating device is adjusted to heat the edges of the slab to obtain a temperature-homogenized slab. Finally, the slab is conveyed to the rolling mill for rolling to complete the hot-rolling production of ultra-low carbon steel. Because this invention precisely controls the edge temperature of the slab, keeping the edge and core temperatures relatively consistent, it effectively suppresses the problem of excessively rapid temperature drop at the edge of the slab, fundamentally reducing the generation of linear defects at the edges of hot-rolled ultra-low carbon steel, and improving the surface quality and first-grade yield of the product.

Description

Technical Field

[0001] This invention relates to the field of hot rolling production, and more particularly to a hot rolling production method and apparatus for ultra-low carbon steel. Background Technology

[0002] Ultra-low carbon steel, due to its low carbon and alloy content, is widely used in industrial production. Its hot rolling process is a crucial step in steel production. The industry's requirements for the surface quality of hot-rolled ultra-low carbon steel products are continuously increasing, necessitating the reduction of edge defects to improve the first-grade yield and ensure market competitiveness. The hot rolling process for ultra-low carbon steel involves a complete series of steps, including blast furnace ironmaking, converter steelmaking, argon blowing, refining, slab continuous casting, heating furnace heating, rolling mill rolling, cooling, and coiling. Process control at each step directly affects the final product quality, with billet temperature control during rolling being a key factor in ensuring the surface quality of ultra-low carbon steel.

[0003] The current production of ultra-low carbon steel hot rolling adopts conventional hot rolling process. After the steel billet is formed by continuous casting, it is transported to the heating furnace for overall heating. After heating, the steel billet is directly transported to the rolling mill for rolling. After rolling, the subsequent processes such as ultra-fast cooling and laminar flow cooling, coiling by the coiler, packaging and coding and warehousing are completed in sequence. In the entire production process, there are no special temperature control measures for the edge of the steel billet. The temperature of the steel billet is raised only by the overall heating of the heating furnace, and the internal temperature distribution of the steel billet is regulated by natural temperature conduction.

[0004] Due to its low carbon and alloy content, ultra-low carbon steel has a high austenite-to-ferrite transformation temperature. During hot rolling, the cooling rate of the billet edges is much faster than that of the center due to the corner effect. This makes it very easy for the billet corners to enter the two-phase region, resulting in poor plasticity at the billet edges. Conventional hot rolling processes lack effective means to suppress the excessively rapid temperature drop at the billet edges, making it impossible to control the billet edge temperature to a suitable range during rolling. Ultimately, this causes linear defects to easily occur at the edges of the billet during rolling, seriously affecting the surface quality of ultra-low carbon steel hot-rolled products and reducing the first-grade product rate. Summary of the Invention

[0005] The main objective of this invention is to provide a hot-rolling production method and apparatus for ultra-low carbon steel, which aims to solve the technical problem in the prior art where the temperature of the billet edge drops too quickly during hot rolling of ultra-low carbon steel, easily causing edge linear defects.

[0006] To achieve the above objectives, the present invention provides a hot-rolled production method for ultra-low carbon steel, the method comprising the following steps: Ultra-low carbon steel is smelted and continuously cast to obtain ultra-low carbon steel slabs. The ultra-low carbon steel slab is transported to a heating furnace for heating treatment to obtain a heated ultra-low carbon steel slab. The heated ultra-low carbon steel slab is transported to the induction heating device in front of the rolling mill to obtain the edge temperature and core temperature of the ultra-low carbon steel slab. The power of the induction heating device is adjusted according to the edge temperature and core temperature of the ultra-low carbon steel slab to heat the edge of the ultra-low carbon steel slab and obtain an ultra-low carbon steel slab with homogenized temperature. The temperature-homogenized ultra-low carbon steel slab is transported to a rolling mill for rolling processing to complete the hot rolling production of ultra-low carbon steel.

[0007] Optionally, the step of smelting and continuously casting ultra-low carbon steel to obtain ultra-low carbon steel slabs includes: Iron ore is processed in a blast furnace to produce molten iron. The molten iron is then transported to a converter for steelmaking to obtain ultra-low carbon steel. The molten ultra-low carbon steel is transported to an argon station for argon blowing to remove impurities from the molten ultra-low carbon steel. The argon-blown ultra-low carbon steel molten steel is transported to a refining furnace for refining to obtain refined ultra-low carbon steel molten steel. The refined ultra-low carbon steel molten steel is transported to a continuous casting machine for continuous casting to obtain ultra-low carbon steel slab.

[0008] Optionally, the step of conveying the ultra-low carbon steel slab to a heating furnace for heat treatment to obtain a heated ultra-low carbon steel slab includes: The ultra-low carbon steel slab is transported to the feed inlet of the heating furnace, and the initial billet temperature of the ultra-low carbon steel slab is detected. The target heating temperature and heating time of the heating furnace are set according to the initial billet temperature of the ultra-low carbon steel slab. The ultra-low carbon steel slab is fed into the heating furnace and heated based on a preset target heating temperature. After continuous heating for the set heating time, the real-time temperature of the ultra-low carbon steel slab is detected. When the real-time temperature of the ultra-low carbon steel slab reaches the preset temperature threshold, the ultra-low carbon steel slab is sent out of the heating furnace to obtain the heated ultra-low carbon steel slab.

[0009] Optionally, the step of conveying the heated ultra-low carbon steel slab to the induction heating device in front of the rolling mill to obtain the edge temperature and core temperature of the ultra-low carbon steel slab includes: Start the first and second induction heating devices on both sides in front of the rolling mill to put the first and second induction heating devices into the standby state. The heated ultra-low carbon steel slab is conveyed to the area between the first induction heating device and the second induction heating device via a conveyor roller. When the ultra-low carbon steel slab is conveyed to the temperature detection area of ​​the induction heating device, the matching temperature detection component is activated. The temperature of multiple detection points on the edge of the ultra-low carbon steel slab is detected by the temperature detection component, and the average temperature of the edge is calculated. The average temperature of the core is calculated by detecting the temperature at multiple detection points in the core of the ultra-low carbon steel slab using the temperature detection component. The average edge temperature and the average core temperature are stored as the edge temperature and core temperature of the ultra-low carbon steel slab.

[0010] Optionally, the step of adjusting the power of the induction heating device according to the edge temperature and core temperature of the ultra-low carbon steel slab to heat the edge of the ultra-low carbon steel slab and obtain a temperature-homogenized ultra-low carbon steel slab includes: Calculate the temperature difference between the core temperature and the edge temperature of the ultra-low carbon steel slab; The temperature difference value is compared numerically with a preset temperature difference threshold. Based on the results of the numerical comparison, the power adjustment parameters of the induction heating device are matched to obtain the target power value; The target power value is sent to the first induction heating device and the second induction heating device respectively, so that the first induction heating device and the second induction heating device operate according to the target power value; The two sides of the ultra-low carbon steel slab are heated separately by the first and second induction heating devices in operation. During the heating process, the edge temperature of the ultra-low carbon steel slab is continuously monitored until the edge temperature and the core temperature are in a relatively consistent range, thus obtaining an ultra-low carbon steel slab after temperature homogenization.

[0011] Optionally, the step of conveying the temperature-homogenized ultra-low carbon steel slab to a rolling mill for rolling processing to complete the hot-rolled production of ultra-low carbon steel includes: The temperature-homogenized ultra-low carbon steel slab is conveyed to the feed end of the rolling mill, and the real-time conveying position of the ultra-low carbon steel slab is detected. When the real-time conveying position of the ultra-low carbon steel slab reaches the preset feeding position of the rolling mill, the rolling mill is started and the rolling process parameters of the rolling mill are set. The ultra-low carbon steel slab after temperature homogenization is rolled by a rolling mill based on preset rolling process parameters to obtain a hot-rolled steel plate. The hot-rolled steel plate is conveyed to a cooling device for continuous cooling treatment of ultra-fast cooling and laminar flow cooling to obtain a cooled hot-rolled steel plate. The cooled hot-rolled steel sheet is conveyed to a coiler for coiling and forming, thus completing the hot-rolling production of ultra-low carbon steel.

[0012] Optionally, the step of adjusting the power of the induction heating device according to the edge temperature and core temperature of the ultra-low carbon steel slab to heat the edge of the ultra-low carbon steel slab and obtain a temperature-homogenized ultra-low carbon steel slab includes: The power adjustment rate of the induction heating device is determined based on the temperature difference to obtain the target adjustment rate. The current power of the induction heating device is gradually adjusted to the target power value according to the target adjustment rate. The rate of temperature change at the edge of the ultra-low carbon steel slab is monitored in real time during power adjustment. The temperature change rate of the edge is compared with a preset temperature change rate threshold. The power regulation rate of the induction heating device is adjusted according to the comparison results so that the edge temperature of the ultra-low carbon steel slab rises steadily. When the edge temperature and core temperature of the ultra-low carbon steel slab are in a relatively consistent range, the power adjustment of the induction heating device is stopped to obtain an ultra-low carbon steel slab with homogenized temperature.

[0013] Optionally, the ultra-low carbon steel slab after temperature homogenization is conveyed to a rolling mill for rolling processing, and the steps to complete the hot rolling production of ultra-low carbon steel include: Surface quality inspection is performed on hot-rolled steel sheets after rolling to identify whether linear defects exist on the surface of the hot-rolled steel sheets; The surface quality test results are compared with a preset quality standard threshold. Continuous processing of hot-rolled steel sheets whose test results meet the preset quality standard thresholds, including coiling, packaging, and inkjet coding; Hot-rolled steel plates whose test results do not meet the preset quality standard threshold are marked with defects and transported to the rework area. The hot-rolled steel plates that have been packaged and marked are transported to the storage area for sorting and storage, thus completing the hot-rolling production of ultra-low carbon steel.

[0014] Optionally, the step of conveying the heated ultra-low carbon steel slab to the induction heating device in front of the rolling mill to obtain the edge temperature and core temperature of the ultra-low carbon steel slab includes: Before activating the temperature detection component, zero-point calibration and accuracy calibration are performed on the temperature detection component to obtain the calibrated temperature detection component; The ambient temperature of the detection area of ​​the induction heating device is detected by the calibrated temperature detection component to obtain the ambient reference temperature; During the process of detecting the temperature of the edge and core of the ultra-low carbon steel slab, the interference of the ambient reference temperature on the detection results is eliminated; Outliers were removed from the temperatures at multiple detection points on the edge and center to obtain valid temperature data. The edge temperature and core temperature of the ultra-low carbon steel slab are obtained by performing an arithmetic average calculation on the effective detected temperature data.

[0015] Furthermore, to achieve the above objectives, the present invention also proposes a hot rolling production apparatus for ultra-low carbon steel using the hot rolling production method for ultra-low carbon steel as described above, the hot rolling production apparatus for ultra-low carbon steel comprising: The smelting and continuous casting module is used to smelt and continuously cast ultra-low carbon steel to obtain ultra-low carbon steel slabs. A heat treatment module is used to transport the ultra-low carbon steel slab to a heating furnace for heat treatment to obtain a heated ultra-low carbon steel slab. The temperature acquisition module is used to transport the heated ultra-low carbon steel slab to the induction heating device in front of the rolling mill and acquire the edge temperature and core temperature of the ultra-low carbon steel slab. The edge heating module is used to adjust the power of the induction heating device according to the edge temperature and core temperature of the ultra-low carbon steel slab, and to heat the edge of the ultra-low carbon steel slab to obtain an ultra-low carbon steel slab with homogenized temperature. The rolling production module is used to transport the temperature-homogenized ultra-low carbon steel slab to the rolling mill for rolling processing, thereby completing the hot rolling production of ultra-low carbon steel.

[0016] This invention involves smelting and continuously casting ultra-low carbon steel to obtain slabs. The slabs are then transported to a heating furnace for heating, and then sent to an induction heating device in front of the rolling mill to obtain the temperatures of the slab's edges and core. The power of the induction heating device is adjusted based on these temperatures to heat the edges of the slab, resulting in a temperature-homogenized slab. Finally, the slab is transported to the rolling mill for hot rolling, completing the hot rolling production of ultra-low carbon steel. This invention achieves precise and layered temperature control during the hot rolling process of ultra-low carbon steel slabs, achieving temperature homogenization of the slab's edges and core at low cost. This fundamentally reduces the generation of linear defects at the edges of hot-rolled ultra-low carbon steel, significantly improving the surface quality and first-grade yield of hot-rolled ultra-low carbon steel products. Furthermore, the process of this invention is highly compatible with existing ultra-low carbon steel hot rolling production lines. The added induction heating device does not require large-scale modifications to the original production line, reducing the equipment investment cost for process optimization. While improving product quality, it also ensures production efficiency, optimizes the process stability and controllability of ultra-low carbon steel hot rolling production, and makes the entire hot rolling production process more suitable for the material characteristics of ultra-low carbon steel, achieving a dual improvement in product quality and production efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic flowchart of the first embodiment of the hot rolling production method of ultra-low carbon steel of the present invention; Figure 2 This is a schematic flowchart of the second embodiment of the hot rolling production method of ultra-low carbon steel of the present invention; Figure 3 This is a schematic flowchart of the third embodiment of the hot rolling production method of ultra-low carbon steel of the present invention; Figure 4 This is a schematic flowchart of the fourth embodiment of the hot rolling production method of ultra-low carbon steel of the present invention; Figure 5 This is a schematic flowchart of the fifth embodiment of the hot-rolling production method of ultra-low carbon steel of the present invention; Figure 6 This is a structural block diagram of the first embodiment of the hot rolling production device for ultra-low carbon steel of the present invention.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0022] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of the invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to the methods, devices, and materials in the embodiments of the present invention.

[0023] This invention provides a hot-rolling production method for ultra-low carbon steel, referring to... Figure 1 , Figure 1 This is a schematic flowchart of an embodiment of the hot rolling production method of ultra-low carbon steel according to the present invention.

[0024] In this embodiment, the hot-rolled production method of ultra-low carbon steel includes the following steps: Step S10: The ultra-low carbon steel is smelted and continuously cast to obtain an ultra-low carbon steel slab.

[0025] It should be noted that ultra-low carbon steel refers to carbon steel with a carbon content far lower than that of ordinary carbon steel, generally with a carbon mass fraction of ≤0.02%, and a low alloy content, possessing good plasticity, toughness and other properties.

[0026] Ultra-low carbon steel slabs refer to plate-shaped billets formed from molten ultra-low carbon steel through continuous casting. They are the core raw materials for hot-rolled ultra-low carbon steel production and have fixed external dimensions such as thickness and width.

[0027] In practice, the iron ore is first processed in a blast furnace to obtain molten iron. The molten iron is then transported to a converter to complete the steelmaking process. The molten steel obtained from steelmaking is then sent to an argon station for argon blowing to degas and remove impurities. The molten steel processed in the argon station is then sent to a refining furnace for composition adjustment and purity improvement. Finally, the qualified ultra-low carbon steel is transported to a continuous casting machine and cast into a uniform slab structure through a continuous casting process to obtain ultra-low carbon steel slabs.

[0028] Step S20: The ultra-low carbon steel slab is transported to a heating furnace for heating treatment to obtain a heated ultra-low carbon steel slab.

[0029] It should be noted that a heating furnace is a special thermal equipment used in the hot rolling production of ultra-low carbon steel to raise the temperature of the slab. It can achieve uniform heating of the slab as a whole and provide the temperature conditions for rolling.

[0030] Heated ultra-low carbon steel slabs refer to slabs that have been heated in a heating furnace to reach the overall temperature required for the hot rolling process of ultra-low carbon steel, and possess the basic plasticity required for rolling.

[0031] In practice, the ultra-low carbon steel slab is smoothly transported to the feeding end of the heating furnace through a roller conveyor system. The initial temperature of the slab is first detected. Based on the material characteristics of ultra-low carbon steel, the target heating temperature and heating time of the heating furnace are set. After the slab is sent into the heating furnace, it is heated at a constant temperature as a whole by means of heat storage heating. After the overall temperature of the slab reaches the hot rolling suitable temperature, it is sent out from the discharge end of the heating furnace to obtain the heated ultra-low carbon steel slab.

[0032] Step S30: The heated ultra-low carbon steel slab is transported to the induction heating device in front of the rolling mill to obtain the edge temperature and core temperature of the ultra-low carbon steel slab.

[0033] It should be noted that the induction heating device can be a heating device installed on both sides in front of the rolling mill, which uses the principle of electromagnetic induction to achieve directional heating of the metal. In this solution, it is used to specifically heat the edges of the ultra-low carbon steel slab.

[0034] It should be noted that the edge temperature of ultra-low carbon steel slab refers to the average temperature of the edge areas on both sides of the ultra-low carbon steel slab, which is the temperature of the area in the slab temperature distribution that is prone to rapid decrease.

[0035] The core temperature of ultra-low carbon steel slab refers to the average temperature of the central region of the ultra-low carbon steel slab. The temperature in this region decreases much more slowly than that at the edges, and it is the reference temperature for the temperature distribution of the slab.

[0036] In practice, the heated ultra-low carbon steel slab is precisely transported to the pre-set induction heating device operating area in front of the rolling mill via the conveyor rollers of the hot rolling production line. The temperature detection component matched with the induction heating device is activated, and multiple points on the edge of the slab are detected using infrared thermometry and other methods. The core area of ​​the slab is also detected at multiple points. The average temperature of the edge and the core is calculated separately. The detected and calculated values ​​are stored as the edge temperature and core temperature of the slab, thus completing the acquisition of temperature data.

[0037] It is understandable that this embodiment accurately acquires temperature distribution data of the edge and core of the ultra-low carbon steel slab, providing a quantitative temperature basis for the subsequent power adjustment of the induction heating device; by detecting multiple points and calculating the average temperature, the accuracy of temperature detection data is improved, avoiding errors at a single detection point that could lead to inaccurate temperature control in the subsequent process, and ensuring the scientific nature of the temperature homogenization process.

[0038] In one embodiment, before activating the temperature detection component, zero-point calibration and accuracy calibration are performed on the temperature detection component to obtain a calibrated temperature detection component. The ambient temperature of the detection area of ​​the induction heating device is detected by the calibrated temperature detection component to obtain an ambient reference temperature. During the detection of the edge and core temperatures of the ultra-low carbon steel slab, the interference of the ambient reference temperature on the detection results is eliminated. Outliers are removed from the multiple detection points of the edge and core temperatures to obtain valid detection temperature data. The arithmetic mean of the valid detection temperature data is calculated to obtain the edge temperature and core temperature of the ultra-low carbon steel slab. The edge temperature and core temperature of the ultra-low carbon steel slab are uploaded and stored in real time to complete the acquisition of the edge temperature and core temperature of the ultra-low carbon steel slab.

[0039] Step S40: Adjust the power of the induction heating device according to the edge temperature and core temperature of the ultra-low carbon steel slab to heat the edge of the ultra-low carbon steel slab and obtain an ultra-low carbon steel slab with homogenized temperature.

[0040] It should be noted that the ultra-low carbon steel slab after temperature homogenization refers to an ultra-low carbon steel slab whose temperature difference between the edge and the core is within the range suitable for the hot rolling process of ultra-low carbon steel, and whose overall temperature distribution is uniform.

[0041] In practice, the temperature difference between the core and edge of the ultra-low carbon steel slab is first calculated. Based on this temperature difference, the power adjustment parameters of the induction heating device are matched to determine the target power value of the device. The target power value is then sent to the induction heating devices on both sides of the rolling mill to complete the power adjustment. The induction heating devices are then started to directionally heat the edges of the slab. During the heating process, the edge temperature of the slab is continuously monitored until the edge temperature and the core temperature of the slab are in a preset relatively consistent range. The heating is then stopped, and the ultra-low carbon steel slab with homogenized temperature is obtained.

[0042] Understandably, this embodiment achieves directional and precise heating of the edge of the ultra-low carbon steel slab, accurately eliminating the temperature difference between the edge and the core of the slab, making the overall temperature distribution of the slab more uniform; it avoids the edge of the slab from entering the two-phase region due to excessively low temperature, effectively improving the plasticity of the slab edge, and fundamentally avoiding the problem of linear defects caused by poor plasticity at the edge during rolling, thus providing a slab with a suitable temperature for subsequent rolling processes.

[0043] Furthermore, to improve temperature control stability and avoid problems such as edge overheating and uneven heating caused by sudden power adjustments, step S40 may include: Step S401: Determine the power adjustment rate of the induction heating device based on the temperature difference to obtain the target adjustment rate; Step S402: Gradually adjust the current power of the induction heating device to the target power value according to the target adjustment rate; Step S403: During the power adjustment process, the temperature change rate at the edge of the ultra-low carbon steel slab is detected in real time; Step S404: Compare the temperature change rate of the edge with a preset temperature change rate threshold; Step S405: Adjust the power regulation rate of the induction heating device according to the comparison results so that the edge temperature of the ultra-low carbon steel slab rises steadily. Step S406: When the edge temperature and core temperature of the ultra-low carbon steel slab are in a relatively consistent range, stop adjusting the power of the induction heating device to obtain an ultra-low carbon steel slab with homogenized temperature.

[0044] It should be noted that the preset temperature change rate threshold can be a reasonable range of edge heating rate set according to the material characteristics of ultra-low carbon steel and the requirements of hot rolling process, and is used to determine whether the edge heating rhythm of the slab is compliant.

[0045] The relatively consistent range refers to the reasonable range of temperature difference between the edge and center of the slab in the hot rolling process of ultra-low carbon steel. The temperature distribution of the slab within this range can meet the plasticity requirements of rolling and is used to determine whether the slab has completed temperature homogenization.

[0046] In the specific implementation, the temperature difference data between the core and the edge of the ultra-low carbon steel slab is retrieved, and the pre-stored power adjustment rate parameter library of the induction heating device is also retrieved. This parameter library contains the basic power adjustment rate corresponding to different temperature difference ranges. The control system matches the corresponding basic power adjustment rate according to the actual temperature difference, and then performs coefficient correction on the basic rate by combining the thickness, width specifications and material characteristics of the ultra-low carbon steel slab to eliminate the influence of slab specification differences on the heating effect. Finally, the power adjustment rate of the induction heating device is determined, and this value is defined as the target adjustment rate. It is then synchronously transmitted to the power control module of the induction heating device to complete the configuration of the rate parameter.

[0047] A power adjustment command is sent to the first and second induction heating devices. The command includes the target adjustment rate and the target power value. After receiving the command, the power control module of the two induction heating devices reads the current working power value of the device and gradually increases the output power at a fixed gradient according to the target adjustment rate. During the power adjustment process, the current actual power value is fed back to the control system in real time. The control system compares the actual adjustment rate with the target adjustment rate to ensure that the power adjustment strictly follows the target adjustment rate until the output power of the device reaches the preset target power value.

[0048] While the induction heating device adjusts its power, the matching temperature detection component is activated and keeps working continuously. This component collects the temperature of the left and right edges of the ultra-low carbon steel slab at preset time intervals, recording the edge temperature value and corresponding collection time for each collection. The continuous temperature and time data are synchronously transmitted to the hot rolling production control system, which calculates the temperature change of the slab edge per unit time using a preset algorithm. This value is the temperature change rate of the ultra-low carbon steel slab edge, and the system refreshes and records this rate in real time.

[0049] The system retrieves the preset temperature change rate threshold corresponding to the hot rolling process of ultra-low carbon steel from the process parameter library. This threshold is a reasonable range of edge heating rate that is suitable for the material characteristics of ultra-low carbon steel. The control system compares the real-time calculated edge temperature change rate of the slab with the preset threshold to determine whether the actual temperature change rate is less than, equal to or greater than the preset temperature change rate threshold, and whether the actual heating rate is within the process adaptation range. The system generates a clear numerical comparison result and pushes it to the rate fine-tuning module.

[0050] Based on the numerical comparison results, corresponding rate fine-tuning operations are performed: if the actual temperature change rate is greater than the preset threshold, it indicates that the edge temperature rises too quickly, and the power adjustment rate of the induction heating device is slightly reduced according to the preset ratio; if the actual temperature change rate is less than the preset threshold, it indicates that the edge temperature rises too slowly, and the power adjustment rate is slightly increased according to the preset ratio; if the actual rate is within the preset threshold range, the current power adjustment rate remains unchanged. After fine-tuning, the edge temperature change rate is continuously monitored and the comparison operation is repeated to form a dynamic closed loop of rate control, ensuring that the edge temperature of the ultra-low carbon steel slab always rises at a steady pace, avoiding sudden temperature rises or stagnation.

[0051] During power regulation and speed fine-tuning, the real-time edge temperature of the slab is continuously compared with the fixed core temperature. The real-time temperature difference between the two is calculated, and it is determined whether the temperature difference falls within the relatively consistent edge-core range preset in the ultra-low carbon steel hot rolling process. When the real-time temperature difference remains within this range and the edge temperature of the slab does not fluctuate significantly, the control system sends a power regulation stop command to the first and second induction heating devices. The two devices immediately maintain their current output power and no longer make adjustments. At this time, the temperature distribution of the edge and core of the ultra-low carbon steel slab reaches the uniform state required by the process, and the temperature homogenization process is completed, resulting in a temperature-homogenized ultra-low carbon steel slab.

[0052] Step S50: The temperature-homogenized ultra-low carbon steel slab is transported to a rolling mill for rolling processing to complete the hot rolling production of ultra-low carbon steel.

[0053] In practice, the temperature-homogenized ultra-low carbon steel slab is conveyed to the feed end of the rolling mill via a conveyor roller. The rolling pass, rolling force and other process parameters of the rolling mill are set according to the hot rolling process requirements of ultra-low carbon steel. The rolling mill is started to perform step-by-step rolling operations on the slab. After rolling, the hot-rolled steel plate is conveyed to the cooling device for ultra-fast cooling and laminar flow cooling. Then, it is coiled by a coiler, packaged and marked, and other subsequent processes are carried out to finally complete the hot rolling production of ultra-low carbon steel.

[0054] It is understood that this embodiment completes the rolling operation on the basis of slab temperature homogenization, ensuring that the slab has uniform overall plasticity during the rolling process, avoiding linear defects at the edges due to poor plasticity, and effectively ensuring the surface quality of ultra-low carbon steel hot-rolled steel plates; through standardized rolling and subsequent supporting processes, the slab is processed into hot-rolled products that meet the specifications, completing the entire process of ultra-low carbon steel hot rolling production, and ensuring the shape and dimensional accuracy of the products.

[0055] In one embodiment, the surface quality of the hot-rolled steel sheet after rolling is inspected to identify whether there are linear defects on the surface of the hot-rolled steel sheet; the results of the surface quality inspection are compared with a preset quality standard threshold; the hot-rolled steel sheets whose inspection results meet the preset quality standard threshold are continuously processed by coiling, packaging and coding; the hot-rolled steel sheets whose inspection results do not meet the preset quality standard threshold are marked with defects and transported to the rework area; the hot-rolled steel sheets that have completed packaging and coding are transported to the storage area for classification and storage, thus completing the hot-rolling production of ultra-low carbon steel.

[0056] Furthermore, to prevent coiling defects such as wrinkling and tearing of the steel sheet and to ensure the forming quality of the steel coil, step S50 above may include: Step S5001: The temperature-homogenized ultra-low carbon steel slab is conveyed to the feed end of the rolling mill, and the real-time conveying position of the ultra-low carbon steel slab is detected. Step S5002: When the real-time conveying position of the ultra-low carbon steel slab reaches the preset feeding position of the rolling mill, start the rolling mill and set the rolling process parameters of the rolling mill; Step S5003: The temperature-homogenized ultra-low carbon steel slab is rolled by a rolling mill based on preset rolling process parameters to obtain a hot-rolled steel plate; Step S5004: The hot-rolled steel plate is conveyed to a cooling device for continuous cooling treatment of ultra-fast cooling and laminar flow cooling to obtain a cooled hot-rolled steel plate; Step S5005: The cooled hot-rolled steel plate is conveyed to a coiler for coiling and forming to complete the hot rolling production of ultra-low carbon steel.

[0057] It should be noted that the preset feed position of the rolling mill is the critical position at the feed end of the rolling mill that marks the start of slab rolling, according to the rolling process requirements of the rolling mill. It is the position node that triggers the start of the rolling mill and the setting of parameters.

[0058] Rolling process parameters refer to various process indicators set to achieve precise rolling of ultra-low carbon steel slabs, including rolling passes, rolling force, roll speed, and reduction.

[0059] It should be noted that ultra-fast cooling refers to a cooling method that uses a high-pressure water curtain to rapidly cool down hot-rolled steel plates. This method can quickly reduce the temperature of the steel plate to the critical region of phase transformation and is a key cooling process for controlling the internal grain structure of the steel plate.

[0060] Laminar flow cooling refers to a cooling method that uses laminar flow cooling water to slowly and uniformly lower the temperature of hot-rolled steel plates. This allows the internal structure of the steel plate to undergo a uniform phase transformation, ensuring the mechanical properties and surface quality of the steel plate.

[0061] In practice, the real-time slab conveying position is continuously compared with the preset feeding position of the rolling mill. When the real-time slab conveying position reaches the preset feeding position, the system immediately sends a start command to the rolling mill. After receiving the command, the rolling mill completes the self-check of the rolls, transmission system, and reduction device and enters the ready-to-roll state. At the same time, the control system retrieves the specification parameters and temperature homogenization data of the ultra-low carbon steel slab, and automatically sets the rolling process parameters such as rolling passes, rolling force, roll speed, and reduction amount of the rolling mill in combination with the process standards of hot rolling of ultra-low carbon steel. The parameters are then sent to the execution modules of the rolling mill and parameter calibration is completed.

[0062] Each execution module of the rolling mill starts operating according to the calibrated rolling process parameters. The roll spacing is adjusted by the pressing device, and the transmission system drives the rolls to rotate at a preset speed. The ultra-low carbon steel slab, after temperature homogenization, enters the space between the rolls under the push of the conveyor rollers. The rolling mill performs progressive plastic deformation rolling on the slab based on the preset rolling passes. After each rolling pass, the thickness and width of the slab are detected in real time, and the rolling parameters are adjusted according to the detection results to ensure that the dimensional accuracy of the slab meets the process requirements. After multiple rolling passes, the slab is processed into a steel plate that meets the preset thickness and width specifications, resulting in a hot-rolled steel plate.

[0063] The rolled hot-rolled steel sheet is rapidly conveyed to the cooling unit's operating area via a conveyor roller. The cooling unit first activates the ultra-fast cooling module, using a high-pressure water curtain to rapidly cool the hot-rolled steel sheet, quickly reducing its temperature to the critical phase transformation temperature range and inhibiting the formation of coarse grains inside the steel sheet. After the ultra-fast cooling treatment, the steel sheet enters the laminar flow cooling module along with the rollers. The cooling unit sprays laminar flow cooling water onto the surface of the steel sheet through laminar flow nozzles, slowly and uniformly cooling the steel sheet to ensure a uniform phase transformation within the steel sheet's internal structure. Simultaneously, the cooling rate and real-time temperature of the steel sheet are monitored, and the cooling water flow rate is adjusted based on the monitoring results to ensure that the cooling process meets the microstructure control requirements of ultra-low carbon steel. Once the steel sheet temperature drops to near the process-adapted temperature of room temperature, continuous cooling is completed, resulting in the cooled hot-rolled steel sheet.

[0064] This embodiment obtains slabs by smelting and continuously casting ultra-low carbon steel. The slabs are then transported to a heating furnace for heating, and then sent to an induction heating device in front of the rolling mill to obtain the temperatures of the slab's edges and core. Based on these temperatures, the power of the induction heating device is adjusted to heat the edges of the slab, resulting in a temperature-homogenized slab. Finally, the slab is transported to the rolling mill for rolling, completing the hot-rolled production of ultra-low carbon steel. This method achieves precise and layered temperature control during the hot rolling process of ultra-low carbon steel slabs, and achieves low-cost temperature homogenization of the slab's edges and core, fundamentally reducing the risk of edge and core temperature problems in hot-rolled ultra-low carbon steel. The elimination of linear defects significantly improves the surface quality and first-grade yield of ultra-low carbon steel hot-rolled products. Furthermore, the process described in this embodiment is highly compatible with existing ultra-low carbon steel hot-rolling production lines. The added induction heating device eliminates the need for large-scale modifications to the original production line, reducing equipment investment costs for process optimization. This approach improves product quality while ensuring production efficiency, optimizing the process stability and controllability of ultra-low carbon steel hot-rolling production. It makes the entire hot-rolling production process more aligned with the material characteristics of ultra-low carbon steel, achieving a dual improvement in product quality and production efficiency.

[0065] refer to Figure 2 , Figure 2 This is a schematic flowchart of the second embodiment of the hot rolling production method of ultra-low carbon steel of the present invention.

[0066] Based on the first embodiment described above, in this embodiment, step S10 further includes: Step S101: Iron ore is processed in a blast furnace to obtain molten iron; Step S102: The molten iron is transported to a converter for steelmaking to obtain ultra-low carbon steel. Step S103: The ultra-low carbon steel molten steel is transported to the argon station for argon blowing treatment to remove impurities from the ultra-low carbon steel molten steel; Step S104: The argon-blown ultra-low carbon steel molten steel is transported to a refining furnace for refining to obtain refined ultra-low carbon steel molten steel. Step S105: The refined ultra-low carbon steel molten steel is transported to a continuous casting machine for continuous casting to obtain ultra-low carbon steel slab.

[0067] In practice, iron ore powder, coke, and flux are selected and mixed according to a preset ratio. The mixed raw materials are continuously fed into the blast furnace through a charging system. Preheated high-temperature hot air is blown in from the blast furnace tuyeres, which allows the coke in the furnace to burn fully and generate high-temperature reducing gas. Under the high-temperature reducing atmosphere of the blast furnace, the iron oxides in the iron ore raw materials are gradually reduced to elemental iron. The molten elemental iron is separated from the slag by gravity. The separated molten iron is periodically discharged from the blast furnace taphole and transported to the ladle through the iron trough to obtain molten iron with composition and temperature that meet the requirements for steelmaking.

[0068] Molten iron from the ladle is transferred to the converter station via a molten iron transport car. The molten iron is then poured into the converter. Based on the initial carbon content and temperature of the molten iron, the oxygen blowing process parameters are set. High-pressure pure oxygen is blown into the molten iron from the converter oxygen lance. The oxygen reacts with elements such as carbon, silicon, and manganese in the molten iron to reduce carbon content, increase temperature, and remove harmful impurities. During the oxygen blowing process, the carbon content and temperature of the molten steel in the furnace are monitored in real time. When the carbon content of the molten steel drops to the standard range for ultra-low carbon steel and the temperature meets the standard, oxygen blowing is stopped and the steel is tapped. The molten steel in the furnace is then transferred to the ladle to obtain ultra-low carbon steel.

[0069] The ladle containing ultra-low carbon steel is hoisted to the argon blowing station. Argon gas permeable bricks are inserted into the bottom of the ladle, and high-pressure argon gas is introduced into the ladle. The argon gas forms a large number of tiny bubbles in the molten steel and floats upward. As the bubbles rise, they adsorb gaseous impurities such as hydrogen and nitrogen, as well as non-metallic inclusions in the molten steel. These impurities float to the surface of the molten steel and enter the slag layer. The molten steel is kept in a stirring state during the argon blowing process. Argon blowing is stopped after the preset blowing time is reached, completing the argon blowing treatment and achieving the initial removal of impurities from the molten steel.

[0070] After argon blowing, the molten ultra-low carbon steel ladle is hoisted to the refining furnace station. The ladle is placed in the electrode heating area of ​​the refining furnace, where the molten steel is heated and kept at a constant temperature to prevent the temperature drop from affecting subsequent processes. Simultaneously, according to the composition standards of ultra-low carbon steel, alloy modifiers are precisely added to the molten steel to accurately control its alloy composition. Sulfur, phosphorus, and non-metallic inclusions in the molten steel can be further removed through slag making and slag removal processes. The composition and temperature of the molten steel are monitored in real time. Once the composition, purity, and temperature of the molten steel meet the standard requirements for hot rolling of ultra-low carbon steel, the refining process is completed, yielding refined ultra-low carbon steel.

[0071] The refined ultra-low carbon steel ladle is hoisted to the tundish station of the continuous casting machine. The molten steel is slowly poured into the tundish for stabilization and temperature equalization. Then, the molten steel is continuously poured into the crystallizer of the continuous casting machine through the tundish. The crystallizer uses a water cooling system to rapidly cool the molten steel inside to form a solidified shell of a certain thickness. The solidified shell is continuously drawn by the billet drawing machine of the continuous casting machine, so that the molten steel gradually completes full solidification during the drawing process. The solidified billet is then straightened and cut to length by the straightening and cutting device of the continuous casting machine to obtain ultra-low carbon steel slabs with regular dimensions and uniform composition.

[0072] This embodiment realizes the complete preparation of ultra-low carbon steel from raw materials to hot-rolled billets. Through multiple processes, deep impurity removal of molten steel is achieved, ensuring the material purity and compositional uniformity of the ultra-low carbon steel slabs. At the same time, the continuous production method of continuous casting improves the billet preparation efficiency. The regular slab shape and stable raw material quality effectively avoid subsequent hot rolling process failures caused by billet defects, uneven composition, and insufficient purity. This provides high-quality and highly stable raw material guarantee for the smooth operation of the entire ultra-low carbon steel hot rolling production process, controlling the basic material quality of ultra-low carbon steel products from the source.

[0073] refer to Figure 3 , Figure 3 This is a schematic flowchart of the third embodiment of the hot rolling production method of ultra-low carbon steel of the present invention.

[0074] Based on the above embodiments, in this embodiment, step S20 further includes: Step S201: The ultra-low carbon steel slab is conveyed to the feed inlet of the heating furnace, and the initial billet temperature of the ultra-low carbon steel slab is detected; Step S202: Set the target heating temperature and heating time of the heating furnace according to the initial billet temperature of the ultra-low carbon steel slab; Step S203: The ultra-low carbon steel slab is fed into the heating furnace and heated based on the preset target heating temperature; Step S204: After continuous heating for the set heating time, detect the real-time temperature of the ultra-low carbon steel slab. Step S205: When the real-time temperature of the ultra-low carbon steel slab reaches the preset temperature threshold, the ultra-low carbon steel slab is sent out of the heating furnace to obtain the heated ultra-low carbon steel slab.

[0075] It should be noted that the initial billet temperature of ultra-low carbon steel slab refers to the overall average temperature of the slab obtained after multi-point detection and data optimization after the ultra-low carbon steel slab is transported to the feed port of the heating furnace and positioned. It is the basis for setting the heating parameters of the heating furnace.

[0076] It should be noted that the target heating temperature can be the constant temperature control temperature set for the heating furnace according to the initial slab temperature of the ultra-low carbon steel slab and the requirements of the ultra-low carbon steel hot rolling process, which is an index for realizing slab heating.

[0077] The preset temperature threshold refers to the heating final temperature standard adapted to the slab rolling requirements in the ultra-low carbon steel hot rolling process, which is a key value for determining whether the slab has completed heating and can be discharged.

[0078] In specific implementation, through the walking beam conveyor of the hot rolling production line, the ultra-low carbon steel slab is smoothly conveyed along the preset conveying path to the designated positioning area at the inlet of the heating furnace, and the positioning induction device at the inlet is triggered to achieve accurate slab positioning; the non-contact infrared temperature measurement component equipped at the inlet is started to perform multi-point temperature detection on the head, middle, tail and upper and lower surfaces of the slab. After removing the abnormal values in the detected data, the arithmetic mean value is calculated, which is used as the initial slab temperature of the ultra-low carbon steel slab, and the data is uploaded to the hot rolling production control system in real time for storage and recording.

[0079] The basic heating parameter library of the ultra-low carbon steel hot rolling process is retrieved, combined with the uploaded initial slab temperature, and according to the material characteristics of the ultra-low carbon steel and the temperature requirements of hot rolling, the corresponding heating control parameters are matched through the process algorithm; if the initial slab temperature is lower than the preset basic slab temperature, the heating rate of the heating furnace is appropriately increased and the heating duration is reasonably extended. If the initial slab temperature is close to the preset basic slab temperature, the heating index is set according to the basic parameters. Finally, the target heating temperature and heating duration of the heating furnace are determined, and the set parameters are sent to the temperature control system of the heating furnace to complete the precise configuration of the heating parameters.

[0080] The gate opening and closing mechanism at the inlet of the heating furnace is controlled to open the inlet gate, and the ultra-low carbon steel slab is conveyed from the inlet to the preset heating area inside the heating furnace through the walking beam in the furnace. Then the inlet gate is closed to ensure the airtightness of the furnace; according to the set target heating temperature, the temperature control system of the heating furnace starts the regenerative burners and heating elements in the furnace to perform zoning temperature control on the preheating section, heating section and soaking section of the heating furnace. The temperature data of each area is collected in real time through the temperature sensors in the furnace, and the burner firepower and heating power are dynamically adjusted according to the feedback data to keep the furnace temperature always stable in the target heating temperature range, and the slab is heated integrally and evenly.

[0081] When the heating duration recorded by the temperature control system of the heating furnace reaches the set value, the temperature measurement and inspection device in the furnace is triggered to perform full-dimensional multi-point temperature detection on the edges, centers and each end face of the ultra-low carbon steel slab. Similarly, the arithmetic mean value is calculated after removing the abnormal values to obtain the overall real-time temperature of the slab; the detected real-time temperature data is uploaded to the hot rolling production control system, compared and analyzed with the set target heating temperature, and a temperature detection report is generated for retention.

[0082] The real-time temperature of the slab is compared with the preset temperature threshold for hot rolling of ultra-low carbon steel. When the real-time temperature reaches the threshold, the gate opening and closing mechanism of the furnace outlet is controlled to open the discharge gate. The slab is then transported from inside the furnace to the conveyor roller at the discharge outlet via the walking beam inside the furnace. The discharge gate is then closed. The conveyor roller transports the slab to the subsequent transfer area of ​​the furnace. At the same time, the heating completion information and final temperature data of the slab are synchronized to the control system of the subsequent process to obtain the heated ultra-low carbon steel slab.

[0083] This embodiment achieves precise, uniform, and controllable heating of ultra-low carbon steel slabs. Through temperature monitoring and dynamic parameter adjustment throughout the entire process, the overall temperature of the slab is effectively increased, significantly enhancing the plasticity of the ultra-low carbon steel slab and fully meeting the temperature and material plasticity requirements for subsequent hot rolling. This lays a solid temperature foundation for subsequent temperature homogenization and rolling operations. Simultaneously, the process allows for customized setting of heating parameters based on the actual conditions of the slab, avoiding ineffective energy consumption and improving the energy utilization efficiency of the heating furnace. Full-process automation and data traceability reduce errors from manual intervention, improving the production stability and standardization of the heating process and effectively preventing subsequent hot rolling defects caused by improper heating.

[0084] refer to Figure 4 , Figure 4 This is a schematic flowchart of the fourth embodiment of the hot rolling production method of ultra-low carbon steel of the present invention.

[0085] Based on the above embodiments, in this embodiment, step S30 further includes: Step S301: Start the first and second induction heating devices on both sides in front of the rolling mill, so that the first and second induction heating devices enter the standby state.

[0086] It should be noted that the first induction heating device / second induction heating device can be two induction heating devices of the same specification symmetrically arranged on both sides in front of the rolling mill, which are used to directionally heat the left and right sides of the ultra-low carbon steel slab respectively, and work together to achieve uniform heating of the slab edges.

[0087] The standby state can be the equipment operating status where the induction heating device has completed self-testing, power reset, and turned off active heating mode, and can receive power adjustment and heating commands at any time. It is a prerequisite for ensuring that the device can quickly respond to subsequent process operations.

[0088] In practice, a start command is sent to the first and second induction heating devices on both sides in front of the rolling mill. After receiving the command, the two induction heating devices automatically complete the self-test of their internal circuits, heating coils, and power adjustment modules to troubleshoot equipment malfunctions. After passing the self-test, the output power of the device is adjusted to the preset initial power (zero power), the active heating mode is turned off, and the device is fed back to the hot rolling production control system with a ready signal. The device is then started and enters the standby state, waiting for subsequent power adjustment and heating commands.

[0089] It is understandable that this embodiment remotely starts the induction heating device and completes the equipment self-check through the control system, thus identifying equipment faults in advance and avoiding inaccurate temperature rise due to equipment problems during subsequent heating; it also puts the device into standby mode to ensure that the device can quickly respond to subsequent power adjustment commands and improve the smoothness of process connection.

[0090] Step S302: The heated ultra-low carbon steel slab is conveyed to the area between the first induction heating device and the second induction heating device via a conveyor roller conveyor.

[0091] It should be noted that the conveyor roller can be a variable frequency speed-regulating roller conveyor used to convey slabs in the hot rolling production of ultra-low carbon steel. It is equipped with side guide plates and laser positioning sensors, which can realize the smooth, accurate and corrective conveying of slabs.

[0092] In practice, the variable frequency speed-regulating conveyor rollers of the hot rolling production line are activated. The preset conveying speed of the rollers is set according to the specifications of the ultra-low carbon steel slab and the speed requirements for subsequent temperature detection. The heated ultra-low carbon steel slab is placed on the conveyor rollers, which smoothly convey the slab at the preset speed. At the same time, the conveying position and deviation of the slab are detected in real time by laser positioning sensors on both sides of the rollers. If the slab deviates, it is corrected in real time by the guide plates on the side of the rollers to ensure that the slab is accurately conveyed along the preset center line to the area between the first and second induction heating devices.

[0093] It is understood that this embodiment uses a variable frequency speed-regulating conveyor roller with laser positioning and real-time correction to achieve stable and accurate conveying of the slab, avoiding deviation of the slab that could lead to deviation of the subsequent temperature detection points or uneven heating; conveying the slab at a preset speed ensures sufficient working time for subsequent temperature detection and improves the integrity of the temperature measurement data.

[0094] Step S303: When the ultra-low carbon steel slab is transported to the temperature detection area of ​​the induction heating device, the matching temperature detection component is activated.

[0095] It should be noted that the temperature detection area can be defined between the first and second induction heating devices, and is a dedicated area for detecting the edge and core temperature of ultra-low carbon steel slabs. It is the working area of ​​the temperature detection component.

[0096] Temperature detection components refer to non-contact temperature measurement devices that are used in conjunction with induction heating devices. They mainly consist of multiple sets of infrared temperature probes, calibration modules, and data transmission modules, and can realize the synchronous acquisition, calibration, and transmission of temperatures at multiple points on the slab.

[0097] In the specific implementation, a dedicated temperature detection area is defined between the first and second induction heating devices, and position trigger sensors are set on both sides of the area. When the position trigger sensors detect that the entire ultra-low carbon steel slab has entered the temperature detection area, they send a trigger signal to the hot rolling production control system. After receiving the signal, the control system sends a start command to the matching temperature detection component. The temperature detection component immediately completes the zero-point calibration and accuracy calibration of the infrared temperature probe, eliminates ambient temperature interference, and enters the temperature measurement working state.

[0098] Step S304: The temperature of multiple detection points on the edge of the ultra-low carbon steel slab is detected by the temperature detection component, and the average temperature of the edge is calculated.

[0099] It should be noted that the multiple temperature detection points on the edge can be a collection of real-time temperature data collected from different locations (head, middle, tail, upper and lower surfaces) on the left and right sides of the ultra-low carbon steel slab.

[0100] The average edge temperature refers to the value obtained by arithmetically averaging the temperature data of effective detection points on the edge of the slab. It is an indicator that characterizes the overall temperature of the edge of the slab.

[0101] In the specific implementation, multiple sets of infrared temperature probes of the temperature detection component are used to perform multi-point temperature detection on the left and right sides of the ultra-low carbon steel slab. At least one detection point is set at the head, middle, tail and upper and lower surfaces of each side, and real-time temperature data of each detection point is collected synchronously. The temperature data of all edge detection points are uploaded to the control system, which automatically removes outliers (such as values ​​that exceed the reasonable temperature range) from the data, and performs an arithmetic average calculation on the remaining valid data to obtain the average temperature of the left side and the average temperature of the right side of the slab. Then, the average temperatures of the two sides are averaged a second time to finally obtain the average edge temperature of the ultra-low carbon steel slab.

[0102] It is understood that this embodiment comprehensively captures the temperature distribution of the slab edge by performing temperature detection on multiple regions and points; and obtains the average edge temperature by outlier removal and secondary averaging, effectively avoiding the random errors of single-point temperature measurement and improving the accuracy and representativeness of edge temperature data.

[0103] Step S305: The temperature of multiple detection points in the core of the ultra-low carbon steel slab is detected by the temperature detection component, and the average core temperature is calculated.

[0104] It should be noted that the temperature at multiple detection points in the core area can be a collection of real-time temperature data collected from different locations (head, middle, and tail) in the central region of the ultra-low carbon steel slab.

[0105] The core average temperature refers to the value obtained by arithmetically averaging the temperature data of effective detection points in the core of the slab. It is an indicator that characterizes the overall temperature of the core of the slab.

[0106] In the specific implementation, the temperature detection component is kept in working condition. Using an infrared temperature probe adapted to the core temperature measurement in the component, the temperature of the central area of ​​the ultra-low carbon steel slab is detected at multiple points. At least one detection point is set at the head, middle and tail of the core of the slab, and real-time temperature data of each detection point is collected. The temperature data of the core detection points is uploaded to the hot rolling production control system, which performs an outlier removal operation and calculates the arithmetic mean of the remaining valid core temperature data to obtain the average core temperature of the ultra-low carbon steel slab.

[0107] Step S306: Store the average edge temperature and the average core temperature as the edge temperature and core temperature of the ultra-low carbon steel slab.

[0108] In the specific implementation, the calculated average edge temperature and average core temperature are defined as the edge temperature and core temperature of the ultra-low carbon steel slab, respectively. The unique identifier of the slab is bound to the corresponding edge temperature and core temperature data, and synchronously transmitted to the hot rolling production process database for classified storage. At the same time, the temperature data is pushed to the power adjustment module of the induction heating device in real time to provide data support for subsequent power adjustment, thus completing the entire temperature acquisition and storage process.

[0109] This embodiment achieves accurate, efficient, and comprehensive acquisition of the edge and core temperatures of ultra-low carbon steel slabs. The entire process significantly improves the accuracy of temperature detection data through multi-point temperature measurement, outlier removal, and averaging calculations, effectively avoiding errors caused by single-point or manual temperature measurement. Simultaneously, equipment linkage and automatic control reduce manual intervention, improving the efficiency and standardization of temperature detection, and providing quantitative and core data for subsequent adjustment of the induction heating device power based on temperature differences.

[0110] refer to Figure 5 , Figure 5 This is a schematic flowchart of the fifth embodiment of the hot rolling production method of ultra-low carbon steel of the present invention.

[0111] Based on the above embodiments, in this embodiment, step S40 further includes: Step S401: Calculate the temperature difference between the core temperature and the edge temperature of the ultra-low carbon steel slab; Step S402: Compare the temperature difference value with a preset temperature difference threshold value; Step S403: Match the power adjustment parameters of the induction heating device according to the result of the numerical comparison to obtain the target power value; Step S404: Send the target power value to the first induction heating device and the second induction heating device respectively, so that the first induction heating device and the second induction heating device operate according to the target power value; Step S405: The two sides of the ultra-low carbon steel slab are heated by the first and second induction heating devices in operation. Step S406: During the heating process, the edge temperature of the ultra-low carbon steel slab is continuously monitored until the edge temperature and the core temperature are in a relatively consistent range, thus obtaining the ultra-low carbon steel slab after temperature homogenization.

[0112] It should be noted that the preset temperature difference threshold can be a critical value for the temperature difference between the edge and the center, set according to the material characteristics of ultra-low carbon steel and the requirements of hot rolling process. It is the criterion for determining whether the slab needs to be heated at the edge and what power parameters to match.

[0113] Power adjustment parameters can be a set of various control parameters when the induction heating device heats the edges, including power adjustment gradient, initial power, power upper limit, etc. Different power adjustment parameters correspond to different temperature difference ranges.

[0114] The target power value refers to the final output power value of the induction heating device for edge heating, which is determined after matching the numerical comparison results and correcting the slab specifications. It is the power index of the device operation.

[0115] The relatively consistent range refers to the reasonable range of edge-to-center temperature difference preset in the hot rolling process of ultra-low carbon steel. The temperature distribution of the slab within this range can meet the plasticity requirements of rolling and is used to determine whether the slab has completed temperature homogenization.

[0116] In practice, the system retrieves the stored core and edge temperature data of the ultra-low carbon steel slab from the process database, performs arithmetic subtraction according to a preset algorithm, subtracts the edge temperature value from the core temperature value to obtain the temperature difference between the core and edge of the slab, and records the calculated temperature difference in real time and transmits it synchronously to the power adjustment judgment module to provide quantitative data for subsequent numerical comparison.

[0117] The power adjustment judgment module retrieves the preset temperature difference threshold in the hot rolling process of ultra-low carbon steel. This threshold is the critical temperature difference between the edge and the center that meets the plasticity requirements of ultra-low carbon steel. The calculated actual temperature difference is precisely compared with the preset temperature difference threshold to determine whether the actual temperature difference is less than, equal to, or greater than the preset temperature difference threshold, generating a clear numerical comparison result. This result is then pushed to the power parameter matching module, which has a pre-stored power adjustment parameter library for the induction heating device. The parameter library includes parameters such as the power adjustment gradient, initial power, and power upper limit corresponding to different temperature difference ranges.

[0118] Based on the numerical comparison results, the corresponding power adjustment parameters are matched from the parameter library. If the actual temperature difference is greater than the preset threshold, a high-gradient power adjustment parameter is matched; if the actual temperature difference is close to the preset threshold, a low-gradient power adjustment parameter is matched. At the same time, the matched parameters are corrected in combination with the thickness and width specifications of the ultra-low carbon steel slab, and finally the target power value of the induction heating device is determined, thus completing the precise configuration of the power parameters.

[0119] The determined target power value is sent to the first induction heating device and the second induction heating device on both sides in front of the rolling mill, respectively. The command includes the target power value and the power adjustment rate requirement. After receiving the command, the power adjustment module of the two induction heating devices gradually adjusts its output power to the target power value according to the rate requirement. After completing the power adjustment, it feeds back the power ready signal to the control system to ensure that both devices reach the preset operating power.

[0120] After both the first and second induction heating devices return a power ready signal, the ultra-low carbon steel slab is kept moving smoothly along the conveyor rollers through the heating area between the two devices at a preset speed. Utilizing the principle of electromagnetic induction, the two devices operate synchronously at the target power value, respectively performing directional induction heating on the left and right sides of the slab. During the heating process, the heating only acts on the edge area of ​​the slab, avoiding significant impact on the temperature of the slab's core, thus achieving targeted heating of the edges.

[0121] While the edge is being heated, a temperature detection component is activated to continuously and dynamically monitor the edge temperature of the ultra-low carbon steel slab, uploading the detected edge temperature data to the hot rolling production control system in real time. The control system continuously compares the real-time edge temperature with the fixed core temperature, calculates the real-time temperature difference, and determines whether the real-time temperature difference falls within the pre-set edge-core relatively consistent range of the ultra-low carbon steel hot rolling process. When the real-time temperature difference remains within this range, the control system sends a power maintenance command to the induction heating device to stop further power increase. At this point, the temperature homogenization process of the slab is completed, resulting in a temperature-homogenized ultra-low carbon steel slab.

[0122] This embodiment achieves directional, precise, and controllable heating of the edges of ultra-low carbon steel slabs, effectively eliminating the temperature difference between the edges and the center of the slab, resulting in a relatively uniform temperature distribution throughout the slab. The entire process is based on the actual temperature difference, enabling precise and personalized adjustment of the induction heating device's power. This avoids overheating or insufficient heating at the edges, improves energy efficiency, and reduces production energy consumption. Simultaneously, the directional heating method aligns with the material characteristics of ultra-low carbon steel, which is prone to rapid temperature drops at the edges, effectively preventing the slab edges from entering the two-phase region. This significantly improves the plasticity of the slab edges, fundamentally avoiding the generation of linear defects at the edges during rolling, and providing temperature-suitable, plastically sound slab raw materials for subsequent rolling operations.

[0123] Reference Figure 6 , Figure 6 This is a structural block diagram of the first embodiment of the hot rolling production device for ultra-low carbon steel of the present invention.

[0124] like Figure 6 As shown, the hot rolling production apparatus for ultra-low carbon steel proposed in this embodiment of the invention includes: The smelting and continuous casting module 10 is used to smelt and continuously cast ultra-low carbon steel to obtain ultra-low carbon steel slabs. The heating treatment module 20 is used to transport the ultra-low carbon steel slab to a heating furnace for heating treatment to obtain a heated ultra-low carbon steel slab. Temperature acquisition module 30 is used to transport the heated ultra-low carbon steel slab to the induction heating device in front of the rolling mill and acquire the edge temperature and core temperature of the ultra-low carbon steel slab. The edge heating module 40 is used to adjust the power of the induction heating device according to the edge temperature and core temperature of the ultra-low carbon steel slab, and to heat the edge of the ultra-low carbon steel slab to obtain an ultra-low carbon steel slab with homogenized temperature. The rolling production module 50 is used to transport the temperature-homogenized ultra-low carbon steel slab to the rolling mill for rolling processing, thereby completing the hot rolling production of ultra-low carbon steel.

[0125] This embodiment obtains slabs by smelting and continuously casting ultra-low carbon steel. After the slabs are heated in a heating furnace, they are sent to an induction heating device in front of the rolling mill to obtain the temperature of the slab's edge and core. The power of the induction heating device is adjusted according to the temperature to heat the slab edges, resulting in a temperature-homogenized slab. Finally, the slabs are sent to the rolling mill for rolling to complete the hot rolling production of ultra-low carbon steel. This method achieves precise and layered temperature control during the hot rolling process of ultra-low carbon steel slabs, and achieves temperature homogenization of the slab's edge and core at low cost. It fundamentally reduces the generation of linear defects at the edges of hot-rolled ultra-low carbon steel, and significantly improves the surface quality and first-grade yield of hot-rolled ultra-low carbon steel products.

[0126] The hot rolling production apparatus for ultra-low carbon steel provided in this application, employing the hot rolling production method for ultra-low carbon steel in the above embodiments, can solve the technical problems in the hot rolling production of ultra-low carbon steel. Compared with the prior art, the beneficial effects of the hot rolling production apparatus for ultra-low carbon steel provided in this application are the same as the beneficial effects of the hot rolling production method for ultra-low carbon steel provided in the above embodiments, and other technical features in the hot rolling production apparatus for ultra-low carbon steel are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0127] It should be understood that the above are merely illustrative examples and do not constitute any limitation on the technical solutions of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any restrictions on this.

[0128] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0129] In addition, for technical details not described in detail in this embodiment, please refer to the hot rolling production method of ultra-low carbon steel provided in any embodiment of the present invention, which will not be repeated here.

[0130] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

Claims

1. A hot-rolling production method for ultra-low carbon steel, characterized in that, The hot-rolling production method of the ultra-low carbon steel includes: Ultra-low carbon steel is smelted and continuously cast to obtain ultra-low carbon steel slabs. The ultra-low carbon steel slab is transported to a heating furnace for heating treatment to obtain a heated ultra-low carbon steel slab. The heated ultra-low carbon steel slab is transported to the induction heating device in front of the rolling mill to obtain the edge temperature and core temperature of the ultra-low carbon steel slab. The power of the induction heating device is adjusted according to the edge temperature and core temperature of the ultra-low carbon steel slab to heat the edge of the ultra-low carbon steel slab and obtain an ultra-low carbon steel slab with homogenized temperature. The temperature-homogenized ultra-low carbon steel slab is transported to a rolling mill for rolling processing to complete the hot rolling production of ultra-low carbon steel.

2. The hot-rolling production method of ultra-low carbon steel as described in claim 1, characterized in that, The steps of smelting and continuously casting ultra-low carbon steel to obtain ultra-low carbon steel slabs include: Iron ore is processed in a blast furnace to produce molten iron. The molten iron is then transported to a converter for steelmaking to obtain ultra-low carbon steel. The molten ultra-low carbon steel is transported to an argon station for argon blowing to remove impurities from the molten ultra-low carbon steel. The argon-blown ultra-low carbon steel molten steel is transported to a refining furnace for refining to obtain refined ultra-low carbon steel molten steel. The refined ultra-low carbon steel molten steel is transported to a continuous casting machine for continuous casting to obtain ultra-low carbon steel slab.

3. The hot-rolling production method of ultra-low carbon steel as described in claim 1, characterized in that, The step of conveying the ultra-low carbon steel slab to a heating furnace for heating treatment to obtain the heated ultra-low carbon steel slab includes: The ultra-low carbon steel slab is transported to the feed inlet of the heating furnace, and the initial billet temperature of the ultra-low carbon steel slab is detected. The target heating temperature and heating time of the heating furnace are set according to the initial billet temperature of the ultra-low carbon steel slab. The ultra-low carbon steel slab is fed into the heating furnace and heated based on a preset target heating temperature. After continuous heating for the set heating time, the real-time temperature of the ultra-low carbon steel slab is detected. When the real-time temperature of the ultra-low carbon steel slab reaches the preset temperature threshold, the ultra-low carbon steel slab is sent out of the heating furnace to obtain the heated ultra-low carbon steel slab.

4. The hot-rolled production method of ultra-low carbon steel as described in claim 1, characterized in that, The step of conveying the heated ultra-low carbon steel slab to the induction heating device in front of the rolling mill and obtaining the edge temperature and core temperature of the ultra-low carbon steel slab includes: Start the first and second induction heating devices on both sides in front of the rolling mill to put the first and second induction heating devices into the standby state. The heated ultra-low carbon steel slab is conveyed to the area between the first induction heating device and the second induction heating device via a conveyor roller. When the ultra-low carbon steel slab is conveyed to the temperature detection area of ​​the induction heating device, the matching temperature detection component is activated. The temperature of multiple detection points on the edge of the ultra-low carbon steel slab is detected by the temperature detection component, and the average temperature of the edge is calculated. The average temperature of the core is calculated by detecting the temperature at multiple detection points in the core of the ultra-low carbon steel slab using the temperature detection component. The average edge temperature and the average core temperature are stored as the edge temperature and core temperature of the ultra-low carbon steel slab.

5. The hot-rolled production method of ultra-low carbon steel as described in claim 1, characterized in that, The step of adjusting the power of the induction heating device according to the edge temperature and core temperature of the ultra-low carbon steel slab to heat the edge of the ultra-low carbon steel slab and obtain a temperature-homogenized ultra-low carbon steel slab includes: Calculate the temperature difference between the core temperature and the edge temperature of the ultra-low carbon steel slab; The temperature difference value is compared numerically with a preset temperature difference threshold. Based on the results of the numerical comparison, the power adjustment parameters of the induction heating device are matched to obtain the target power value; The target power value is sent to the first induction heating device and the second induction heating device respectively, so that the first induction heating device and the second induction heating device operate according to the target power value; The two sides of the ultra-low carbon steel slab are heated separately by the first and second induction heating devices in operation. During the heating process, the edge temperature of the ultra-low carbon steel slab is continuously monitored until the edge temperature and the core temperature are in a relatively consistent range, thus obtaining an ultra-low carbon steel slab after temperature homogenization.

6. The hot-rolled production method of ultra-low carbon steel as described in claim 1, characterized in that, The step of conveying the temperature-homogenized ultra-low carbon steel slab to a rolling mill for rolling processing to complete the hot-rolled production of ultra-low carbon steel includes: The temperature-homogenized ultra-low carbon steel slab is conveyed to the feed end of the rolling mill, and the real-time conveying position of the ultra-low carbon steel slab is detected. When the real-time conveying position of the ultra-low carbon steel slab reaches the preset feeding position of the rolling mill, the rolling mill is started and the rolling process parameters of the rolling mill are set. The ultra-low carbon steel slab after temperature homogenization is rolled by a rolling mill based on preset rolling process parameters to obtain a hot-rolled steel plate. The hot-rolled steel plate is conveyed to a cooling device for continuous cooling treatment of ultra-fast cooling and laminar flow cooling to obtain a cooled hot-rolled steel plate. The cooled hot-rolled steel sheet is conveyed to a coiler for coiling and forming, thus completing the hot-rolling production of ultra-low carbon steel.

7. The hot-rolled production method of ultra-low carbon steel as described in claim 1, characterized in that, The step of adjusting the power of the induction heating device according to the edge temperature and core temperature of the ultra-low carbon steel slab to heat the edge of the ultra-low carbon steel slab and obtain a temperature-homogenized ultra-low carbon steel slab includes: The power adjustment rate of the induction heating device is determined based on the temperature difference to obtain the target adjustment rate. The current power of the induction heating device is gradually adjusted to the target power value according to the target adjustment rate. The rate of temperature change at the edge of the ultra-low carbon steel slab is monitored in real time during power adjustment. The temperature change rate of the edge is compared with a preset temperature change rate threshold. The power regulation rate of the induction heating device is adjusted according to the comparison results so that the edge temperature of the ultra-low carbon steel slab rises steadily. When the edge temperature and core temperature of the ultra-low carbon steel slab are in a relatively consistent range, the power adjustment of the induction heating device is stopped to obtain an ultra-low carbon steel slab with homogenized temperature.

8. The hot-rolled production method of ultra-low carbon steel as described in claim 1, characterized in that, The step of conveying the temperature-homogenized ultra-low carbon steel slab to a rolling mill for rolling processing to complete the hot-rolled production of ultra-low carbon steel includes: Surface quality inspection is performed on hot-rolled steel sheets after rolling to identify whether linear defects exist on the surface of the hot-rolled steel sheets; The surface quality test results are compared with a preset quality standard threshold. Continuous processing of hot-rolled steel sheets whose test results meet the preset quality standard thresholds, including coiling, packaging, and inkjet coding; Hot-rolled steel plates whose test results do not meet the preset quality standard threshold are marked with defects and transported to the rework area. The hot-rolled steel plates that have been packaged and marked are transported to the storage area for sorting and storage, thus completing the hot-rolling production of ultra-low carbon steel.

9. The hot-rolled production method of ultra-low carbon steel as described in claim 1, characterized in that, The step of conveying the heated ultra-low carbon steel slab to the induction heating device in front of the rolling mill and obtaining the edge temperature and core temperature of the ultra-low carbon steel slab includes: Before activating the temperature detection component, zero-point calibration and accuracy calibration are performed on the temperature detection component to obtain the calibrated temperature detection component; The ambient temperature of the detection area of ​​the induction heating device is detected by the calibrated temperature detection component to obtain the ambient reference temperature; During the process of detecting the temperature of the edge and core of the ultra-low carbon steel slab, the interference of the ambient reference temperature on the detection results is eliminated; Outliers were removed from the temperatures at multiple detection points on the edge and center to obtain valid temperature data. The edge temperature and core temperature of the ultra-low carbon steel slab are obtained by performing an arithmetic average calculation on the effective detected temperature data.

10. A hot-rolling production apparatus for ultra-low carbon steel, characterized in that, The device includes: The smelting and continuous casting module is used to smelt and continuously cast ultra-low carbon steel to obtain ultra-low carbon steel slabs. A heat treatment module is used to transport the ultra-low carbon steel slab to a heating furnace for heat treatment to obtain a heated ultra-low carbon steel slab. The temperature acquisition module is used to transport the heated ultra-low carbon steel slab to the induction heating device in front of the rolling mill and acquire the edge temperature and core temperature of the ultra-low carbon steel slab. The edge heating module is used to adjust the power of the induction heating device according to the edge temperature and core temperature of the ultra-low carbon steel slab, and to heat the edge of the ultra-low carbon steel slab to obtain an ultra-low carbon steel slab with homogenized temperature. The rolling production module is used to transport the temperature-homogenized ultra-low carbon steel slab to the rolling mill for rolling processing, thereby completing the hot rolling production of ultra-low carbon steel.

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