Control system and method for calcium aluminate inclusions and related equipment

Abstract

The invention discloses a calcium aluminate inclusion control system and method and related equipment, and relates to the technical field of continuous casting, and the system comprises a control assembly which is used for generating a pulse current parameter instruction based on a target steel grade; the power supply assembly is used for receiving the pulse current parameter instruction sent by the control assembly to generate pulse current; the positive electrode assembly is arranged at the position away from the first side face of the crystallizer by a first preset distance and connected with the positive electrode of the power source assembly, and the crystallizer is used for containing molten steel corresponding to the target steel grade; and the negative electrode assembly is arranged at the position away from the second side face of the crystallizer by the first preset distance and connected with the negative electrode of the power supply assembly, and the first side face and the second side face are opposite side faces of the crystallizer. According to the calcium aluminate inclusion control system, inclusion inhibition is achieved, and increase of cost and environment burden is avoided while the cleanliness of IF steel is guaranteed.

Description

Technical Field

[0001] This application relates to the field of continuous casting technology, and in particular to a control system, method and related equipment for calcium aluminate inclusions. Background Technology

[0002] Calcium aluminate inclusions are non-metallic impurities generated during ladle changes in IF steel (interstitial aluminate steel) continuous casting due to slag runoff. Their presence is particularly significant in the production of high-quality automotive steel sheets, as it can significantly reduce the mechanical properties and surface quality of the steel. These inclusions tend to aggregate into large particles during solidification, leading to defects such as cracking and deformation during stamping, severely impacting product yield. Traditional control methods, such as optimizing the refining slag composition or modifying the ladle structure, can reduce inclusions to some extent, but they suffer from high costs and low efficiency. Furthermore, existing electric field technologies are prone to current leakage due to the conductivity of the protective slag, weakening the control effect on inclusions in the molten steel. Therefore, a control system for calcium aluminate inclusions is urgently needed to address the aforementioned problems. Summary of the Invention

[0003] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key and essential technical features of the claimed technical solutions, nor is it intended to determine the scope of protection of the claimed technical solutions.

[0004] In a first aspect, this application provides a control system for calcium aluminate inclusions, comprising:

[0005] A control component, wherein the control component is used to generate pulse current parameter commands based on the target steel grade;

[0006] A power supply component, wherein the power supply component is used to receive the pulse current parameter command issued by the control component to generate a pulse current;

[0007] A positive electrode assembly is disposed at a position at a first preset distance from the first side of the crystallizer and is connected to the positive electrode of the power supply assembly. The crystallizer is used to contain molten steel corresponding to the target steel grade.

[0008] The negative electrode component is disposed at a distance from the second side of the crystallizer at a first preset distance, and is connected to the negative electrode of the power supply component. The first side and the second side are the opposite sides of the crystallizer.

[0009] The positive electrode assembly, the molten steel, the negative electrode assembly, and the power supply assembly form a closed loop to conduct the pulse current.

[0010] In some embodiments, the positive electrode component and the negative electrode component are material rods made of alumina and graphite composite; or, the positive electrode component and the negative electrode component are material rods made of silicon carbide and graphite composite.

[0011] In some embodiments, the positive electrode assembly includes a first outer end and a first inner end, and the negative electrode assembly includes a second outer end and a second inner end, wherein the first inner end and the second inner end are disposed inside the crystallizer, and the first outer end and the second outer end are disposed outside the crystallizer.

[0012] In some embodiments, the distance between the first inner end and the surface of the molten steel is a second preset distance; the distance between the second inner end and the surface of the molten steel is a second preset distance, wherein the second preset distance is greater than or equal to the first preset immersion distance and less than or equal to the second preset immersion distance.

[0013] In some embodiments, the crystallizer includes a protective slag layer.

[0014] An insulating coating layer covers the portions of the positive electrode assembly and the negative electrode assembly located in the protective slag layer; the insulating coating layer includes a ceramic sleeve or a refractory coating, used to block current conduction between the positive electrode assembly and the negative electrode assembly and the protective slag layer.

[0015] Secondly, this application proposes a method for controlling calcium aluminate inclusions, used in the control system described in any of the first aspects, comprising:

[0016] Obtain the target steel grade during the casting process;

[0017] Based on the target steel grade, determine the pulse current parameters;

[0018] The power supply component is controlled to output a pulse current corresponding to the pulse current parameter to the positive electrode component and the negative electrode component, so as to form a pulse electric field in the molten steel through the positive electrode component and the negative electrode component;

[0019] Among them, based on the solidification process of molten steel under the action of pulsed electric field, a target billet with reduced calcium aluminate inclusion content is obtained.

[0020] In some embodiments, after obtaining the target billet with reduced calcium aluminate inclusion content in the solidification process of the molten steel based on the pulsed current, the method further includes:

[0021] Obtain test samples within a preset depth range of the target casting billet;

[0022] Based on the ASPEX inclusion analysis algorithm, the calcium aluminate inclusions in the test sample are scanned and detected, and the detection results are generated.

[0023] Based on the test results and the preset qualified threshold, the quality grade of the target billet is determined.

[0024] Thirdly, this application proposes a control device for calcium aluminate inclusions, comprising:

[0025] The target steel grade acquisition unit is used to acquire the target steel grade during the casting process;

[0026] A current parameter determination unit is used to determine pulse current parameters based on the target steel grade;

[0027] A pulse current application unit is used to control the power supply component to output a pulse current corresponding to the pulse current parameter to the positive electrode component and the negative electrode component, so as to form a pulse electric field in the molten steel through the positive electrode component and the negative electrode component;

[0028] Among them, based on the solidification process of molten steel under the action of pulsed electric field, a target billet with reduced calcium aluminate inclusion content is obtained.

[0029] Fourthly, an electronic device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program stored in the memory to implement the steps of the method for controlling calcium aluminate inclusions according to any one of the second aspects.

[0030] Fifthly, this application also proposes a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the steps of the method for controlling calcium aluminate inclusions according to any of the second aspects.

[0031] In summary, the control system for calcium aluminate inclusions proposed in this application includes: a control component for generating pulse current parameter commands based on the target steel grade; a power supply component for receiving pulse current parameter commands from the control component and generating pulse current; a positive electrode component, located at a first preset distance from the first side of the crystallizer and connected to the positive electrode of the power supply component, the crystallizer being used to contain the molten steel corresponding to the target steel grade; and a negative electrode component, located at a first preset distance from the second side of the crystallizer and connected to the negative electrode of the power supply component, the first and second sides being opposite sides of the crystallizer. The control system for calcium aluminate inclusions proposed in this application directly applies pulse current to the molten steel of the target steel grade within the crystallizer, using electric field force to drive the directional migration of calcium aluminate inclusions and promote their agglomeration and flotation, thereby reducing the number density and average size of inclusions in the billet. The above control system does not require the addition of chemical reagents or modification of smelting equipment; inclusion suppression can be achieved simply by optimizing current parameters. While ensuring the cleanliness of IF steel, it avoids the cost and environmental burden of traditional processes, providing efficient and reliable technical support for the production of high-precision steels such as automotive steel sheets. Attached Figure Description

[0032] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit this specification. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0033] Figure 1 A schematic diagram of a control system structure for calcium aluminate inclusions provided in an embodiment of this application;

[0034] Figure 2 A schematic flowchart of a method for controlling calcium aluminate inclusions provided in an embodiment of this application;

[0035] Figure 3 A schematic diagram of a control device for calcium aluminate inclusions provided in an embodiment of this application;

[0036] Figure 4 This is a schematic diagram of a control electronic device for calcium aluminate inclusions provided in an embodiment of this application.

[0037] The correspondence between the reference numerals and component names in the figure is as follows: 100 is the control component, 101 is the power supply component, 1021 is the positive electrode component, 1022 is the negative electrode component, 103 is the protective slag layer, 104 is the surface of the molten steel, 105 is the molten steel, 106 is the stopper rod, 107 is the tundish, 108 is the submerged entry nozzle, and 109 is the crystallizer. Detailed Implementation

[0038] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. The technical solutions of the embodiments of this application 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 this application, and not all of them.

[0039] Please see Figure 1This is a schematic diagram of a control system structure for calcium aluminate inclusions provided in an embodiment of this application, which may specifically include:

[0040] Control component 100 is used to generate pulse current parameter commands based on the target steel grade;

[0041] Power supply component 101 is used to receive pulse current parameter instructions from control component 100 and generate pulse current.

[0042] The positive electrode component 1021 is located at a distance of a first preset distance from the first side of the crystallizer 109 and is connected to the positive electrode of the power supply component 101. The crystallizer 109 contains molten steel corresponding to the target steel grade.

[0043] The negative electrode component 1022 is located at a distance of a first preset distance from the second side of the crystallizer 109 and is connected to the negative electrode of the power supply component 101. The first side and the second side are the sides of the crystallizer 109 opposite to each other.

[0044] Among them, the positive electrode component 1021, the molten steel 105, the negative electrode component 1022 and the power supply component 101 form a closed loop to conduct pulse current.

[0045] For example, such as Figure 1 As shown, the working principle of the control system for calcium aluminate inclusions is as follows: The control component 100 acquires the target steel grade identification information (such as IF steel grade IF-1) in real time during the casting process. Based on the preset steel grade and parameter mapping relationship, it generates pulse current parameter commands (e.g., current intensity 80A, frequency 4000Hz, duty cycle 80%) and sends them to the power supply component 101. The molten steel is injected into the crystallizer 109 through the submerged entry nozzle 108 after the flow control of the stopper rod 106 from the tundish 107. The surface 104 of the molten steel in the crystallizer 109 is covered with a protective slag layer 103, which is used to isolate air and absorb inclusions. The power supply component 101 receives instructions from the control component 100, generates a pulse current with corresponding parameters, and connects two symmetrically arranged positive electrode components 1021 and negative electrode components 1022 through positive and negative electrode cables. Both positive electrode components 1021 and negative electrode components 1022 are high-temperature resistant conductive refractory rods. The refractory rods are made of conductive composite materials and are vertically inserted into both sides of the narrow face of the crystallizer 109. Their lower ends penetrate the protective slag layer 103 and are immersed in the molten steel 105. The distance between them and the surface 104 of the molten steel is a first preset distance L4. The upper ends extend to the outside of the crystallizer 109. The power supply component 101, positive electrode component 1021, molten steel 105 and negative electrode component 1022 form a closed loop.

[0046] When energized, a pulsed current is directly introduced into the molten steel 105 via the refractory rod, creating a non-uniform electric field within the molten steel 105. Under the influence of this electric field, calcium aluminate inclusions become polarized, and negatively charged particles migrate directionally towards the anode refractory rod (positive electrode component 1021), colliding and agglomerating. Simultaneously, the electric field force reduces the interfacial tension between the inclusions and the molten steel 105. The agglomerated and enlarged inclusions are accelerated to float to the protective slag layer 103 where they are absorbed, achieving efficient separation. During this process, the insulating outer layer of the refractory rod blocks current leakage to the protective slag layer 103, ensuring that the electric field energy is concentrated on the inclusions in the molten steel 105, thereby improving the impurity removal efficiency.

[0047] It should be noted that the distance between the positive electrode component 1021 and the first side of the crystallizer 109 is a first preset distance L5, and the distance between the negative electrode component 1022 and the second side of the crystallizer 109 is also a first preset distance L5; the first preset distance L5 ranges from 5cm to 10cm (preferably 8cm). This symmetrical layout ensures that the current forms a uniform electric field distribution perpendicular to the first side and the second side in the molten steel 105.

[0048] The thickness of the protective slag layer 103 is L3, which is 50mm. The vertical distance between the first inner end of the positive electrode assembly 1021 and the second inner end of the negative electrode assembly 1022 and the surface 104 of the molten steel is a second preset distance L4. The second preset distance L4 is greater than or equal to the first preset immersion distance and less than or equal to the second preset immersion distance. The first preset immersion distance is 50mm and the second preset immersion distance is 100mm. In the cross-sectional dimensions of the crystallizer 109, the width parallel to the first and second sides is the first preset length L1, and the length perpendicular to the first and second sides is the second preset length L2. The length L1 can be set to 200mm-250mm, and the width L2 can be set to 900mm-2000mm. The diameters of the positive electrode assembly 1021 and the negative electrode assembly 1022 are both greater than or equal to the first preset diameter and less than or equal to the second preset diameter. The first preset diameter is 1cm and the second preset diameter is 2cm. The above parameters synergistically optimize the electric field distribution and the stability of the molten steel flow field.

[0049] In some instances, the positive electrode assembly 1021, molten steel 105, negative electrode assembly 1022, and power supply assembly 101 form a closed loop to conduct pulsed current.

[0050] For example, power supply component 101 is connected to the first outer end of positive electrode component 1021 via a positive cable and to the second outer end of negative electrode component 1022 via a negative cable, forming an external conductive circuit. Both positive electrode component 1021 and negative electrode component 1022 are high-temperature resistant conductive composite refractory rods (such as alumina-graphite or silicon carbide-graphite materials), and their inner ends (first inner end and second inner end) penetrate the protective slag layer 103 in the crystallizer 109 and are immersed in the molten steel 105 to a second preset distance L4. When power supply component 101 outputs a pulse current, the current is injected into the molten steel 105 from the first inner end of positive electrode component 1021, and after flowing through the molten steel 105, the current is led out from the second inner end of negative electrode component 1022, forming a closed current loop of power supply component 101 → positive electrode component 1021 → molten steel 105 → negative electrode component 1022 → power supply component 101. This circuit concentrates the electric field energy inside the molten steel 105, creating a non-uniform electric field distribution within it. Under the influence of the electric field, the calcium aluminate inclusions become polarized and carry a net negative charge. Driven by Coulomb force, they migrate directionally towards the anode (positive electrode component 1021). During this migration, the particles collide and agglomerate, increasing in size. Simultaneously, the electric field force reduces the interfacial tension between the inclusions and the molten steel 105, causing the agglomerates to accelerate upwards to the protective slag layer 103 where they are absorbed, thus achieving effective separation of the inclusions from the molten steel 105.

[0051] In some instances, the positive electrode component 1021 and the negative electrode component 1022 are made of a composite material of alumina and graphite; or, the positive electrode component 1021 and the negative electrode component 1022 are made of a composite material of silicon carbide and graphite.

[0052] For example, the positive electrode assembly 1021 and the negative electrode assembly 1022 are made of high-temperature resistant conductive composite materials, specifically including two optional options. One is an alumina-graphite composite material, wherein the alumina (Al2O3) content is 70-80wt% and the graphite content is 20-30wt%. This material maintains a resistivity of 5-15μΩ·m at a steel molten temperature of 1400-1550℃, ensuring efficient current conduction. This material can maintain structural integrity at a steel molten temperature of 1520-1550℃, and its thermal shock resistance ensures the stability of the electrode under fluctuating casting temperatures. The high-temperature insulating properties of the alumina component suppress the bypass leakage of current to the protective slag layer 103, concentrating the electric field energy inside the steel molten 105. The second type is a silicon carbide-graphite composite material, in which the silicon carbide (SiC) content is 60-70 wt% and the graphite content is 30-40 wt%, with a resistivity of 2-8 μΩ·m, significantly lower than that of the alumina system. This makes it suitable for applications requiring high current density (such as current increases to 180A during ladle changing). The high thermal conductivity of the silicon carbide component accelerates heat diffusion within the electrode, preventing localized overheating and melting losses. At the same time, the self-lubricating properties of the graphite phase reduce the erosion of the electrode by the molten steel flow field.

[0053] Through the above material design, the positive electrode component 1021 and the negative electrode component 1022 form a stable current injection in the molten steel 105, ensuring the sustainability of the directional migration and agglomeration effect of the pulsed electric field on calcium aluminate inclusions, and providing a hardware foundation for efficient separation of inclusions.

[0054] In some instances, the positive electrode assembly 1021 includes a first outer end and a first inner end, and the negative electrode assembly 1022 includes a second outer end and a second inner end. The first inner end and the second inner end are disposed inside the crystallizer 109, and the first outer end and the second outer end are disposed outside the crystallizer 109.

[0055] For example, power supply component 101 is connected to the first outer end of positive electrode component 1021 via a positive cable, and simultaneously connected to the second outer end of negative electrode component 1022 via a negative cable, forming a complete external circuit conduction path. The first inner end of positive electrode component 1021 and the second inner end of negative electrode component 1022 are vertically inserted into the crystallizer 109 and symmetrically arranged on both sides of the narrow face of crystallizer 109. The aforementioned first and second inner ends completely penetrate the protective slag layer 103 and are immersed in the molten steel 105, with their immersion depth controlled within a second preset distance L4. The first and second outer ends extend to the outside of crystallizer 109 and are physically connected to the positive and negative electrodes of power supply component 101 via high-temperature resistant cables. Both positive electrode component 1021 and negative electrode component 1022 are constructed of composite refractory rods, with the material selected being an alumina-graphite or silicon carbide-graphite system, and the diameter specification limited to the range of 1cm to 2cm. The refractory rod is entirely covered by a ceramic sleeve insulation layer. This insulation layer completely covers the section of the refractory rod located within the protective slag layer 103, effectively blocking the leakage path of current to the protective slag layer 103 and ensuring that the pulse current is concentrated inside the molten steel 105. During installation and positioning, the distance between the first inner end of the positive electrode assembly 1021 and the narrow surface of the crystallizer 109 is set to a first preset distance L5 (ranging from 5cm to 10cm), and the second inner end of the negative electrode assembly 1022 is symmetrically arranged with the same spacing. This symmetrical structure creates a horizontal electric field distribution perpendicular to the narrow surface in the molten steel 105, optimizing the directional migration path of calcium aluminate inclusions. When the power supply assembly 101 outputs a pulse current, the current is injected into the molten steel 105 from the first inner end of the positive electrode assembly 1021, flows through the molten steel 105, and is then discharged from the second inner end of the negative electrode assembly 1022, forming a closed loop of power supply assembly 101 → positive electrode assembly 1021 → molten steel 105 → negative electrode assembly 1022 → power supply assembly 101. This circuit establishes a non-uniform electric field within the molten steel 105, driving negatively charged calcium aluminate particles to migrate directionally towards the anode and collide and aggregate, ultimately achieving efficient separation of inclusions.

[0056] In some instances, the distance between the first inner end and the surface 104 of the molten steel is a second preset distance; the distance between the second inner end and the surface 104 of the molten steel is a second preset distance, and the second preset distance is greater than or equal to the first preset immersion distance and less than or equal to the second preset immersion distance.

[0057] For example, the vertical distance between the first inner end of the positive electrode assembly 1021 and the molten steel surface 104 is defined as the second preset distance L4, and the vertical distance between the second inner end of the negative electrode assembly 1022 and the molten steel surface 104 is also the second preset distance L4. This distance satisfies: L4 ≥ first preset immersion distance 50mm and L4 ≤ second preset immersion distance 100mm. This range is set based on the following synergistic mechanism:

[0058] Minimum depth guarantee: when L4 ≥ 50 mm, the inner end of the electrode can completely penetrate the protective slag layer 103 and be deeply buried inside the molten steel 105. This depth ensures that the current injection point is far away from the turbulent zone on the surface of the molten steel 104, avoiding interruption of current conduction caused by the fluctuation of the protective slag; at the same time, it allows the electric field to effectively cover the high-temperature molten steel zone (the area rich in inclusions) at the bottom of the crystallizer 109, enhancing the electromigration effect on the sinking calcium aluminate particles.

[0059] The maximum depth limit, when L4 ≤ 100mm, prevents the electrode from penetrating too deeply into the molten steel 105 and disturbing the formation of the initial solidified shell. Excessive insertion will interfere with the stability of the molten steel flow field near the narrow face, increasing the risk of surface cracks in the billet; at the same time, it ensures that the lower end of the electrode maintains a safe distance from the copper plate of the crystallizer to avoid short circuit accidents caused by thermal expansion.

[0060] Symmetry requires that the first inner terminal of the positive electrode assembly 1021 and the second inner terminal of the negative electrode assembly 1022 maintain the same L4 value (i.e., L4 is equal), so that the current forms a horizontally symmetrical electric field distribution in the molten steel 105. For example... Figure 1 As shown, when the positive electrode assembly 1021 and the negative electrode assembly 1022 are symmetrically arranged on both sides of the narrow surface of the crystallizer 109 at a first preset distance L5, the equal depth L4 causes the electric field lines to extend parallel to the direction of the narrow surface, driving the negatively charged calcium aluminate inclusions to migrate directionally towards the anode along the horizontal path, thereby increasing the probability of collision and aggregation.

[0061] In some instances, the crystallizer 109 includes a protective slag layer 103.

[0062] An insulating covering layer covers the portions of the positive electrode assembly 1021 and the negative electrode assembly 1022 located in the protective slag layer 103; the insulating covering layer includes a ceramic sleeve or a refractory coating, used to block current conduction between the positive electrode assembly 1021 and the negative electrode assembly 1022 and the protective slag layer 103.

[0063] For example, an insulating coating layer is provided on the outside of the positive electrode assembly 1021 and the negative electrode assembly 1022. This insulating coating layer is made of non-conductive refractory material or ceramic sleeve, and its thickness is a preset insulation thickness. The insulating coating layer completely covers the entire section of the refractory rod located within the protective slag layer 103, specifically extending upward from the surface of the molten steel 104 to the upper boundary of the protective slag layer 103, and downward to the starting position where the refractory rod is immersed in the molten steel 105. Current path blocking is achieved based on the material properties of the insulating coating layer. The resistivity of the non-conductive refractory material (e.g., refractory castable with an alumina content ≥95wt%) or the ceramic sleeve (e.g., yttrium-stabilized zirconia ceramic) is much higher than that of the molten steel 105, forming a high barrier. When a pulse current is introduced from the power supply assembly 101 through the first outer end of the positive electrode assembly 1021, the current is confined to the conductive refractory core inside the insulating coating layer until it is injected into the molten steel 105 from the first inner end. The high resistance of the insulating coating layer blocks the leakage path of current to the protective slag layer 103, ensuring that the electric field energy is concentrated inside the molten steel 105 and avoiding energy loss due to bypass current.

[0064] The insulating coating and electrode cooling system form a synergistic thermal management mechanism. A circulating water-cooling channel (water temperature controlled ≤30℃) is installed inside the refractory rod, with the channel diameter accounting for 30%-40% of the electrode diameter. The insulating coating tightly covers the outside of the water-cooling channel; its low thermal conductivity effectively inhibits the radial transfer of heat from the molten steel 105 to the electrode interior, while simultaneously blocking the thermal radiation from the external protective slag layer 103. This dual thermal protection system maintains the electrode operating temperature below the material's critical softening point (alumina-graphite composite <1450℃, silicon carbide-graphite composite <1600℃), preventing high-temperature deformation or melting of the electrode. The complete coverage of the insulating coating also eliminates direct contact between the protective slag layer 103 and the electrode, avoiding the risk of current leakage caused by the conductivity of the protective slag. This ensures that the effective electric field strength in the molten steel 105 is stably maintained within the optimized range of 50-200V / m, guaranteeing the electromigration and agglomeration efficiency of calcium aluminate inclusions.

[0065] Please see Figure 2 This is a schematic flowchart of a method for controlling calcium aluminate inclusions provided in an embodiment of this application, which may specifically include:

[0066] S110, Obtain the target steel grade during the casting process;

[0067] For example, during the start-up phase of continuous casting production, the metallurgical process control system collects the identification information of the target steel grade (such as IF steel grades IF-1, IF-2, etc.) in real time. This identification information is associated with the basic metallurgical properties of the molten steel. Based on the preset mapping relationship between the steel grade identification and the tendency of calcium aluminate inclusion formation, a steel grade classification basis is provided for subsequent pulse current regulation, ensuring that differentiated control strategies are implemented for different steel grades.

[0068] S120. Determine the pulse current parameters based on the target steel grade;

[0069] For example, based on the acquired target steel grade identification information (such as IF-1), a suitable range of pulse current parameters is determined through a preset steel grade and parameter mapping relationship. This mapping model associates the chemical composition characteristics of different steel grades (such as aluminum content and calcium treatment process) with the electric field requirements, outputting a basic control range for current intensity, frequency, and duty cycle. During the casting process, this parameter range serves as a benchmark framework for dynamic adjustment, ensuring that the pulse electric field exerts a directional control effect on the migration and agglomeration behavior of calcium aluminate inclusions, while balancing the stability of the molten steel flow field and energy efficiency.

[0070] S130, the control power supply component outputs a pulse current corresponding to the pulse current parameter to the positive and negative components, so as to form a pulse electric field in the molten steel through the positive and negative components; wherein, based on the solidification process of the molten steel after the action of the pulse electric field, a target billet with reduced calcium aluminate inclusion content is obtained.

[0071] For example, a pulsed current is applied to the molten steel corresponding to the target steel grade within the crystallizer. This drives the electromigration of calcium aluminate inclusions through an electric field. The pulsed current creates a non-uniform electric field in the molten steel, causing negatively charged calcium aluminate particles to move directionally towards the anode and agglomerate, while simultaneously reducing the interfacial tension between the inclusions and the molten steel. The agglomerated inclusions, due to their increased size, rise more rapidly to the protective slag layer, achieving effective separation from the molten steel. This process continues until the end of casting, ultimately yielding a target billet with a significantly reduced calcium aluminate inclusion content, thus suppressing the destructive effects of calcium aluminate inclusions on the steel's properties.

[0072] In summary, this application's embodiments utilize pulsed current applied directly to the molten steel of the target steel grade within the crystallizer. This electric field drives the directional migration of calcium aluminate inclusions and promotes their collision and aggregation, effectively reducing the interfacial tension between the inclusions and the molten steel and accelerating the flotation and separation of large particles to the protective slag layer. This process significantly inhibits the formation and aggregation of calcium aluminate inclusions in the cast billet, particularly reducing the number density of particles >50μm, thus improving the cleanliness of the steel. This method does not rely on chemical additives or complex equipment modifications; efficient impurity removal can be achieved simply by optimizing current parameters. While ensuring the mechanical properties and surface quality of IF steel, it overcomes the technical shortcomings of traditional processes, such as high operating costs and poor environmental compatibility, providing green and reliable technical support for the production of high-end steels such as automotive steel sheets.

[0073] In some instances, after obtaining a target billet with reduced calcium aluminate inclusion content in the solidification process of molten steel based on pulsed current, the process also includes:

[0074] Obtain test samples within a preset depth range of the target cast billet;

[0075] Based on the ASPEX inclusion analysis algorithm, calcium aluminate inclusions in the test sample are scanned and detected, and the detection results are generated.

[0076] Based on the test results and the preset qualified threshold, the quality grade of the target billet is determined.

[0077] For example, the preset sampling specification limits the sampling area to a depth of 5mm to 20mm from the surface of the billet cross-section (this area is rich in calcium aluminate inclusions). A water-cooled wire cutter is used to cut cubic samples with dimensions of 10mm × 10mm × 10mm. Argon gas is used for protection during the cutting process to prevent sample oxidation. The number of samples is set according to the casting batch size, with at least 3 samples taken from each casting batch and the sampling location coordinates marked to ensure that the test results characterize the overall quality of the billet.

[0078] The sample was scanned and detected using the ASPEX inclusion analysis algorithm. The sample surface was polished to mirror finish (roughness Ra ≤ 0.05 μm) and placed on the ASPEX Explorer scanning electron microscope stage. The electron beam energy was set to 20 kV and the beam spot size to 1 μm, with an automatic grid scan of the sample surface in 0.5 μm increments. Calcium aluminate inclusions (CaO-Al2O3 compounds) were located using atomic number contrast identification (Z ≥ 11) and morphological screening of non-metallic inclusions (aspect ratio > 2 indicates chain aggregates). The system automatically recorded the equivalent diameter, position coordinates, and composition spectrum of each inclusion, generating a number density (inclusions / mm²). 2 The dataset contains the detection results of average size (μm) and sphericity (proportion of spherical particles).

[0079] The quality grade is determined based on the test results and a preset acceptable threshold. The preset acceptable threshold includes the following indicators: a number density threshold of >50μm calcium aluminate inclusions of 0.8 inclusions / mm. 2 (Set according to automotive outer panel rolling process requirements). The judgment logic is as follows: if the number density of inclusions >50μm in the tested sample is ≤0.8 inclusions / mm. 2 If the sphericity rate is ≥90%, the quality grade is marked as Grade A (suitable for direct use in automotive outer panel production); if the quantity density is ≤1.0 pieces / mm 2 But >0.8 per mm 2 If the quantity density is > 1.0 pieces / mm, it will be marked as Grade B (and must be downgraded for use on inner panels); 2 If the sphericity rate is <85%, it is marked as Grade C (judged as a non-conforming product, triggering the process backtracking mechanism).

[0080] In summary, this application establishes a quality verification system for controlling calcium aluminate inclusions through standardized sampling and automated ASPEX analysis. Using the number density of inclusions >50μm as the criterion, combined with the morphological sphericity index, the effect of pulsed current impurity removal is objectively quantified. The three-level judgment criteria are directly related to downstream product grades (such as automotive outer / inner panels), providing data support for production process optimization. Compared to traditional metallographic manual grading, this method improves the accuracy of inclusion detection to the micrometer level, and the detection results are traceable to specific casting parameters (such as current intensity and frequency), driving iterative upgrades in the impurity removal process.

[0081] The technical solution of this application will be further described in detail below through specific embodiments.

[0082] When implementing the method for controlling calcium aluminate inclusions as proposed in this application on a twin-strand slab continuous casting machine at a steel plant, the target steel grade identification code (such as ultra-low carbon steel grade IF-1) is first obtained through the metallurgical process control system. The molten steel composition corresponding to this steel grade is C≤0.003wt%, Al=0.02-0.07wt%, and its high aluminum characteristics make it prone to generating CaO-Al2O3 series inclusions. Based on the characteristics of the steel grade, the initial control range of the pulse current parameters is set, namely, current intensity 50-200A, frequency 1000-40000Hz, and duty cycle 20%-80%.

[0083] Electrode assemblies are symmetrically installed on both sides of the narrow face of the crystallizer 109. The positive electrode assembly 1021 and the negative electrode assembly 1022 are made of silicon carbide-graphite composite refractory rods (1.5cm in diameter, 65wt% SiC content, 35wt% graphite), and the first preset distance L5 from the narrow face of the crystallizer 109 is 8cm. The depth to which the first inner end of the positive electrode assembly 1021 and the second inner end of the negative electrode assembly 1022 are immersed in the molten steel 105 is controlled to a second preset distance L4 = 100mm, ensuring that the lower end face of the electrode completely penetrates the 50mm thick protective slag layer 103 and is deeply buried inside the molten steel 105. The power supply assembly 101 connects the first outer end of the positive electrode assembly 1021 and the second outer end of the negative electrode assembly 1022 through a high-temperature resistant cable, forming a closed circuit. The insulation layer blocks the leakage path of current to the protective slag layer 103, so that the pulse current is concentrated inside the molten steel 105.

[0084] During the casting process, the pulse current parameters are adjusted in stages. In the initial casting stage, when the casting speed stabilizes at 0.8 m / min, the first parameter configuration is executed. The power supply component 101 outputs a pulse current of 80 A, a frequency of 4000 Hz, and a duty cycle of 80%. This low-frequency, high-duty-cycle parameter creates a strong electric field gradient in the molten steel 105, driving large calcium aluminate inclusions (>50 μm) to migrate and collide towards the anode, accelerating their agglomeration and floating to the protective slag layer 103. During the stable casting period, when the casting speed reaches the target speed of 1.2 m / min, the second parameter configuration is switched. The power supply component 101 adjusts its output to 120 A, a frequency of 8000 Hz, and a duty cycle of 40%. The high-frequency pulse enhances the Brownian motion of fine inclusions (<20 μm), while the low-duty-cycle intermittent electric field reduces the surface charge shielding effect of the particles, promoting collision and agglomeration. The third parameter configuration is executed during the ladle changing stage and before the end of each casting heat. The power supply component 101 increases the current to 180A, maintaining a frequency of 9000Hz and a duty cycle of 45%. The high current density enhances the migration effect of the electric field on large particle inclusions introduced by the vortex slag, thus purifying the junction area.

[0085] After casting, test samples were taken from the cross-section of the billet at a depth of 5mm-20mm from the surface. 10mm×10mm×10mm cubic samples were obtained using wire cutting equipment and polished under argon protection until the surface roughness Ra ≤ 0.05μm. Inclusion analysis was performed using an ASPEX Explorer scanning electron microscope with an electron beam energy of 20kV, a beam spot size of 1μm, and a scanning step size of 0.5μm. CaO-Al2O3 compounds were identified based on atomic number contrast. Statistical analysis showed that the number density of calcium aluminate inclusions was 1.2 inclusions / mm². 2 Reduced to 0.7 per mm 2 The average size decreased from 75μm to 12μm, and the proportion of spherical particles increased to 92%. This case study demonstrates that the synergistic effect of electrode insulation design, immersion depth control, and dynamic adjustment of current parameters can significantly suppress the hazards of calcium aluminate inclusions and improve the cleanliness and product qualification rate of IF steel.

[0086] Please see Figure 3 The diagram below illustrates the structure of a control device for calcium aluminate inclusions provided in this application, comprising:

[0087] The target steel grade acquisition unit 21 is used to acquire the target steel grade during the casting process;

[0088] The current parameter determination unit 22 is used to determine the pulse current parameters based on the target steel grade;

[0089] The pulse current application unit 23 is used to control the power supply component to output a pulse current corresponding to the pulse current parameter to the positive electrode component and the negative electrode component, so as to form a pulse electric field in the molten steel through the positive electrode component and the negative electrode component; wherein, based on the solidification process of the molten steel after the action of the pulse electric field, a target billet with reduced calcium aluminate inclusion content is obtained.

[0090] Please see Figure 4 This application also provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor. When the processor 320 executes the computer program 311, it implements the steps of a method for controlling calcium aluminate inclusions.

[0091] Since the electronic device described in this embodiment is the device used to implement the control device for calcium aluminate inclusions in the embodiments of this application, those skilled in the art can understand the specific implementation method and various variations of the electronic device in this embodiment based on the method described in the embodiments of this application. Therefore, how the electronic device implements the method in the embodiments of this application will not be described in detail here. Any device used by those skilled in the art to implement the method in the embodiments of this application is within the scope of protection of this application.

[0092] In practice, when the computer program 311 is executed by the processor, it can implement any of the embodiments corresponding to the first aspect.

[0093] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0094] Those skilled in the art will understand that embodiments of this application can provide methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-readable storage media containing computer-readable program code.

[0095] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0096] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0097] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0098] This application also provides a computer program product, which includes computer software instructions that, when executed on a processing device, cause the processing device to perform... Figure 2 The flowchart of a method for controlling calcium aluminate inclusions in a corresponding embodiment.

[0099] A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, computer instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any usable medium that a computer can store or a data storage device such as a server or data center that integrates one or more usable media. The usable medium may be a magnetic medium, an optical medium, or a semiconductor medium, etc.

[0100] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0101] In the several embodiments provided in this application, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Furthermore, the mutual couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0102] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0103] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units described above can be implemented in the form of hardware and / or software functional units.

[0104] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device to execute all or part of the steps of the methods in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, magnetic disks, or optical disks.

[0105] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

[0106] Although preferred embodiments have been described in this specification, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications that fall outside the scope of this specification.

[0107] Obviously, those skilled in the art can make various modifications to this specification without departing from its spirit and scope. Therefore, this specification also intends to include any modifications that fall within the scope of the claims and their equivalents.

Claims

1. A control system for calcium aluminate inclusions, characterized in that, include: A control component, wherein the control component is used to generate pulse current parameter commands based on the target steel grade; A power supply component, wherein the power supply component is used to receive the pulse current parameter command issued by the control component to generate a pulse current; A positive electrode assembly is disposed at a position at a first preset distance from the first side of the crystallizer and is connected to the positive electrode of the power supply assembly. The crystallizer is used to contain molten steel corresponding to the target steel grade. The negative electrode component is disposed at a distance from the second side of the crystallizer at a first preset distance, and is connected to the negative electrode of the power supply component. The first side and the second side are the opposite sides of the crystallizer. The positive electrode assembly, the molten steel, the negative electrode assembly, and the power supply assembly form a closed loop to conduct the pulse current.

2. The system according to claim 1, characterized in that, The positive electrode component and the negative electrode component are material rods made of alumina and graphite composite; or, the positive electrode component and the negative electrode component are material rods made of silicon carbide and graphite composite.

3. The system according to claim 1, characterized in that, The positive electrode assembly includes a first outer end and a first inner end, and the negative electrode assembly includes a second outer end and a second inner end. The first inner end and the second inner end are disposed inside the crystallizer, and the first outer end and the second outer end are disposed outside the crystallizer.

4. The system according to claim 3, characterized in that, The distance between the first inner end and the surface of the molten steel is a second preset distance; the distance between the second inner end and the surface of the molten steel is a second preset distance, and the second preset distance is greater than or equal to the first preset immersion distance and less than or equal to the second preset immersion distance.

5. The system according to claim 1, characterized in that, The crystallizer includes a protective slag layer. An insulating coating layer covers the portions of the positive electrode assembly and the negative electrode assembly located in the protective slag layer; the insulating coating layer includes a ceramic sleeve or a refractory coating, used to block current conduction between the positive electrode assembly and the negative electrode assembly and the protective slag layer.

6. A method for controlling calcium aluminate inclusions, used in the control system according to any one of claims 1-5, characterized in that, include: Obtain the target steel grade during the casting process; Based on the target steel grade, determine the pulse current parameters; The power supply component is controlled to output a pulse current corresponding to the pulse current parameter to the positive electrode component and the negative electrode component, so as to form a pulse electric field in the molten steel through the positive electrode component and the negative electrode component; wherein, based on the solidification process of the molten steel after the action of the pulse electric field, a target billet with reduced calcium aluminate inclusion content is obtained.

7. The method according to claim 6, characterized in that, After obtaining the target billet with reduced calcium aluminate inclusion content in the solidification process of molten steel based on pulsed current, the process further includes: Obtain test samples within a preset depth range of the target casting billet; Based on the ASPEX inclusion analysis algorithm, the calcium aluminate inclusions in the test sample are scanned and detected, and the detection results are generated. Based on the test results and the preset qualified threshold, the quality grade of the target billet is determined.

8. A control device for calcium aluminate inclusions, characterized in that, include: The target steel grade acquisition unit is used to acquire the target steel grade during the casting process; A current parameter determination unit is used to determine pulse current parameters based on the target steel grade; A pulsed current application unit is used to control the power supply component to output a pulsed current corresponding to the pulsed current parameter to the positive electrode component and the negative electrode component, so as to form a pulsed electric field in the molten steel through the positive electrode component and the negative electrode component; wherein, based on the solidification process of the molten steel after the action of the pulsed electric field, a target billet with reduced calcium aluminate inclusion content is obtained.

9. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program stored in the memory to implement the steps of the method for controlling calcium aluminate inclusions as described in any one of claims 6 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for controlling calcium aluminate inclusions as described in any one of claims 6 to 7.

Images