Control method and production process of high-magnetic-induction oriented silicon steel and obtained steel

Abstract

The invention provides a control method and a production process of high-magnetic-induction oriented silicon steel and obtained steel. The method comprises the steps that molten iron and scrap steel are mixed and then smelted in a converter, and first molten steel is obtained; the first molten steel is subjected to RH furnace refining, and refined molten steel is obtained; the refined molten steel is sequentially subjected to continuous casting, hot rolling, normalizing annealing and cold rolling treatment, and a cold-rolled steel plate is obtained; and the cold-rolled steel sheet is subjected to decarburization annealing treatment, and the high-magnetic-induction oriented silicon steel is obtained. Through mutual cooperation of the process steps, the chemical composition of the refined molten steel is accurately controlled, and the technical problems that in the prior art, the mass fraction of nitrogen in steel is difficult to accurately control, and the magnetic performance of existing high-magnetic-induction oriented silicon steel is poor are solved. The control method is simple and convenient to operate, the iron loss is reduced through effective control over the content of all the elements, the magnetism of the high-magnetic-induction oriented silicon steel is improved, and therefore the production efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of steel smelting, and particularly relates to the control method, production process and obtained steel of high magnetic induction oriented silicon steel. Background Technology

[0002] In the steel production industry, nitrogen microalloying is widely used as an important method to improve steel performance and save on expensive alloys. Nitrogen microalloying can improve various properties of steel, such as mechanical properties and corrosion resistance, while reducing dependence on some expensive alloying elements, thereby lowering production costs and demonstrating significant economic value and application prospects. However, controlling the nitrogen content in steel faces many challenges in practical applications. On the one hand, the nitrogen content in steel cannot be too high, as excessive nitrogen content can easily affect the quality of the steel, leading to defects such as cracks, which in turn affects the mechanical and performance properties of the steel, making it unable to meet relevant requirements in practical applications and greatly reducing the reliability and service life of the steel. In grain-oriented silicon steel, nitrogen, as an important inhibitor, plays a crucial role in the magnetic properties of the steel. If the nitrogen content is too low, the inhibitor will be insufficient, and the magnetic properties of the steel will be significantly reduced, failing to meet the standard requirements for high-magnetic-induction grain-oriented silicon steel, thus limiting its application in high-magnetic-induction fields. Therefore, how to determine the optimal nitrogen content in steel under zero-defect conditions has become a key issue in the application of nitrogen in grain-oriented silicon steel. Based on this, the present invention provides a control method, production process and resulting steel for high magnetic induction oriented silicon steel, to solve the technical problems of difficulty in accurately controlling the nitrogen mass fraction in steel and the poor magnetic properties of existing high magnetic induction oriented silicon steel. Summary of the Invention

[0003] The main objective of this invention is to provide a control method, production process, and resulting steel for high magnetic induction oriented silicon steel, aiming to solve the technical problems of difficulty in accurately controlling the nitrogen mass fraction in steel and the poor magnetic properties of existing high magnetic induction oriented silicon steel.

[0004] To achieve the above objectives, the present invention provides a method for controlling high magnetic induction oriented silicon steel, comprising the following steps: S1: Molten iron and scrap steel are mixed and then smelted in a converter to obtain the first molten steel.

[0005] S2: The first molten steel is refined in an RH furnace to obtain refined molten steel.

[0006] S3: The refined molten steel is subjected to continuous casting, hot rolling, normalizing annealing and cold rolling in sequence to obtain cold-rolled steel sheet.

[0007] S4: The cold-rolled steel sheet is subjected to decarburization annealing treatment to obtain the high magnetic induction oriented silicon steel.

[0008] The chemical composition of the refined steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) 0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

[0009] According to the embodiments of this application, the nitrogen solubility of each phase during the cooling phase transformation of steel is calculated using Thermol-Calc software.

[0010] According to an embodiment of this application, the nitrogen content of the high magnetic induction oriented silicon steel is equal to the sum of the nitrogen solubility in ferrite and austenite when the nitrogen in the gas phase reaches its maximum.

[0011] According to embodiments of this application, the acid-soluble aluminum (Al) in the high magnetic induction oriented silicon steel... (S) The content is equal to the nitrogen content of the high magnetic induction oriented silicon steel × 27 ÷ 14.

[0012] According to embodiments of this application, the acid-soluble aluminum Al (S) The content of aluminum is determined by ladle testing during the continuous casting process, and aluminum loss is considered when controlling the acid-soluble aluminum content in RH refining. This aluminum loss is calculated using an empirical formula, which includes: Where t is the interval between RH outbound component detection and mid-package component detection, in minutes; α (FeTOT) The activity of FeTOT in RH slag is calculated using FactSage software.

[0013] This invention also provides a production process for high magnetic induction oriented silicon steel, comprising the following steps: The high magnetic induction oriented silicon steel is obtained by converter smelting, RH furnace refining, continuous casting, hot rolling, normalizing annealing, cold rolling, decarburizing annealing, magnesium oxide coating, and high temperature annealing.

[0014] The nitrogen content in the high magnetic induction oriented silicon steel is determined according to the control method for high magnetic induction oriented silicon steel described above.

[0015] The chemical composition of the high magnetic induction oriented silicon steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S)0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

[0016] This invention also provides a high-magnetic-induction oriented silicon steel, prepared according to the above-described control method or production process for high-magnetic-induction oriented silicon steel. The composition of the high-magnetic-induction oriented silicon steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al... (S) 0.015%~0.02%, Cu 0.49%~0.52%, N 0.008%~0.011%, the remainder being Fe and other unavoidable impurity elements.

[0017] The magnetic induction of the high magnetic induction oriented silicon steel is ≥1.9T.

[0018] According to an embodiment of this application, the size of the AlN and CuS composite inhibitor in the continuously cast billet of the high magnetic induction oriented silicon steel is ≤90 nm.

[0019] According to an embodiment of this application, the size of the AlN-CuS composite inhibitor in the hot-rolled plate of the high magnetic induction oriented silicon steel is 20 nm to 70 nm.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: The aforementioned method for controlling the content of elements such as C, Si, and Mn in high-magnetic-induction oriented silicon steel involves adjusting the ratio of molten iron to scrap steel to initially control the content of these elements, providing a low-phosphorus, low-sulfur base steel for subsequent RH furnace refining. RH furnace refining allows for precise adjustment of the steel's chemical composition, meeting the stringent requirements of high-magnetic-induction oriented silicon steel for inhibitors (AlN, MnS). Reducing the sulfur content to below 0.012% avoids hot brittleness, improves magnetic properties, and reduces iron loss. Hot rolling promotes the solution dissolution of inhibitors (AlN, MnS), providing sufficient inhibition for subsequent secondary recrystallization. Through the coordinated operation of each process step, the chemical composition of the refined steel is precisely controlled, solving the technical problems of difficulty in accurately controlling the nitrogen mass fraction in steel and the poor magnetic properties of existing high-magnetic-induction oriented silicon steel.

[0021] Moreover, the control method of the present invention is simple and easy to operate. By effectively controlling the content of each element, iron loss is reduced and the magnetism of high magnetic induction oriented silicon steel is increased, thereby improving production efficiency and reducing production costs. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 The solubility diagram of nitrogen in different phases during the cooling phase transformation of high magnetic induction oriented silicon steel, calculated using Thermo-Calc thermodynamic software in Example 1, is shown. The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] To achieve the above objectives, the present invention provides a method for controlling high magnetic induction oriented silicon steel, comprising the following steps: S1: Molten iron and scrap steel are mixed and then smelted in a converter to obtain the first molten steel.

[0027] In some embodiments, the ratio of molten iron to scrap steel is not specifically limited and the raw material ratio can be flexibly adjusted to optimize costs while ensuring that the basic composition of the molten steel meets the standards. Converter smelting can efficiently remove harmful impurities such as carbon, phosphorus, and sulfur from the raw materials, improving the purity of the molten steel and laying the foundation for the magnetic properties of subsequent silicon steel. Simultaneously, the rapid heating and oxidation reaction during converter smelting can refine the steel crystal grains, improve the fluidity of the molten steel, and facilitate subsequent refining and continuous casting.

[0028] S2: The first molten steel is refined in an RH furnace to obtain refined molten steel.

[0029] The chemical composition of the refined steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) 0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

[0030] In some embodiments, RH furnace refining can further remove impurities such as oxygen and sulfur from the first molten steel, reduce inclusion content, and improve the purity and uniformity of the molten steel. This allows for precise adjustment of the chemical composition of the refined steel to meet the compositional requirements of high-magnetic-induction grain-oriented silicon steel.

[0031] S3: The refined molten steel is subjected to continuous casting, hot rolling, normalizing annealing and cold rolling in sequence to obtain cold-rolled steel sheet.

[0032] In some embodiments, refined molten steel is continuously cast to achieve continuous forming, ensuring uniform billet size and dense microstructure, and reducing defects such as porosity and segregation within the billet. Hot rolling refines the grains through high-temperature plastic deformation, improving the steel's machinability and providing qualified slabs for cold rolling. Normalizing annealing removes iron oxide scale from the surface of the hot-rolled plate, preventing the scale from affecting the cold rolling process and the surface quality of the finished product.

[0033] S4: The cold-rolled steel sheet is subjected to decarburization annealing treatment to obtain the high magnetic induction oriented silicon steel.

[0034] In some embodiments, decarburization annealing can eliminate internal stress generated during cold rolling, preventing deformation of the cold-rolled steel sheet in subsequent use. Simultaneously, it promotes grain recrystallization and orientation optimization in the steel, forming grain orientations beneficial to magnetic properties, significantly improving the permeability of high-magnetic-orientation silicon steel and reducing iron loss. This ensures that the finished silicon steel is less prone to breakage during subsequent cutting, lamination, and other applications.

[0035] The aforementioned control method for high-magnetic-induction oriented silicon steel forms a complete closed loop of "smelting - refining - forming - processing - heat treatment," with each step working synergistically to ensure product quality from multiple dimensions, including composition, purity, microstructure, and dimensions. By adjusting the ratio of molten iron to scrap steel, the content of elements such as C, Si, and Mn in the molten steel is initially controlled, providing a low-phosphorus, low-sulfur base steel for subsequent RH furnace refining. RH furnace refining allows for precise adjustment of the molten steel's chemical composition, meeting the stringent requirements of high-magnetic-induction oriented silicon steel for inhibitors (AlN, MnS). The sulfur content is reduced to below 0.012%, preventing hot brittleness, improving magnetic properties, and reducing iron loss. Hot rolling promotes the solidification of inhibitors (AlN, MnS), providing sufficient inhibition for subsequent secondary recrystallization. Through the coordinated operation of each process step, the chemical composition of the refined molten steel is precisely controlled, solving the technical problems of difficulty in accurately controlling the nitrogen mass fraction in steel and the poor magnetic properties of existing high-magnetic-induction oriented silicon steel. Furthermore, by precisely controlling the chemical composition and grain orientation, high magnetic induction and low iron loss oriented silicon steel can be obtained to meet the demand for high-efficiency magnetic materials in electrical equipment such as transformers and motors.

[0036] Moreover, the control method of the present invention is simple and easy to operate. By effectively controlling the content of each element, iron loss is reduced and the magnetism of high magnetic induction oriented silicon steel is increased, thereby improving production efficiency and reducing production costs.

[0037] In some embodiments, Thermol-Calc software is used to calculate the nitrogen solubility of each phase during the cooling phase transformation of steel.

[0038] In some embodiments, Thermo-Calc software, based on a thermodynamic database, is used to quantitatively calculate the solubility of nitrogen in various phases such as austenite (γ), ferrite (α), martensite, and nitrides (e.g., AlN, CrN, TiN) at different temperatures and compositions. This avoids the high-cost trial-and-error process of traditional "experiment-detection-adjustment" methods, effectively shortening the development cycle of new materials. Thermo-Calc calculations allow for precise control of nitrogen addition, suppressing the precipitation of harmful nitrides.

[0039] In some embodiments, the phase appearance order during the cooling phase transformation of high-magnetic-induction grain-oriented silicon steel is liquid phase-ferrite phase-austenite phase-precipitated phase. In the calculation, a supersaturation calculation method is used, with the input nitrogen content far exceeding the sum of the nitrogen solubility of each phase in the steel, allowing for the calculation of the nitrogen solubility of each phase in the steel under certain pressure and temperature conditions. During the cooling phase transformation of high-magnetic-induction grain-oriented silicon steel, sufficient AlN phase formation must be ensured, but excessive nitrogen content should not lead to bubble formation. If the nitrogen content exceeds the nitrogen solubility of each phase or the sum of the nitrogen solubility of each phase within the same time period, nitrogen will become a gaseous phase, adversely affecting the steel. AlN is an inhibitor in grain-oriented silicon steel, capable of increasing magnetic induction; its full precipitation should be ensured as much as possible.

[0040] In some embodiments, the nitrogen content of the high magnetic induction oriented silicon steel is equal to the sum of the nitrogen solubility in ferrite and austenite when nitrogen in the gas phase reaches its maximum.

[0041] In some embodiments, the suitable nitrogen content of the high magnetic induction oriented silicon steel is equal to the sum of the nitrogen solubility in ferrite and austenite when nitrogen in the gas phase reaches its maximum.

[0042] In some embodiments, when the nitrogen content exceeds the sum of the solubilities of ferrite (α) and austenite (γ), the excess nitrogen will spontaneously precipitate AlN / Si3N4 at grain boundaries or dislocations, forming hard and brittle nanoclusters, which become the initiation point of microcracks in subsequent cold rolling deformation, resulting in surface defects in high magnetic orientation silicon steel.

[0043] In some embodiments, precisely matching the stoichiometric ratio of Al to N promotes the full precipitation of AlN, avoiding insufficient nitrogen content leading to low AlN precipitation (which cannot effectively inhibit abnormal grain growth) or excessive nitrogen causing residual free nitrogen (leading to steel embrittlement and decreased magnetic inductance). Controlling the nitrogen content within the nitrogen solubility range of AlN can reduce the formation of other harmful nitrides (such as TiN and BN), preventing such inclusions from disrupting grain orientation continuity and reducing iron loss.

[0044] In some embodiments, the acid-soluble aluminum (Al) of the high magnetic induction oriented silicon steel (S) The content is equal to the nitrogen content of the high magnetic induction oriented silicon steel × 27 ÷ 14.

[0045] In some embodiments, acid-soluble aluminum (Al) (S) It is the effective aluminum component that combines with nitrogen to form AlN. Its content directly determines the maximum precipitation of AlN, avoiding insufficient AlN precipitation due to insufficient effective aluminum, or resource waste due to excessive aluminum. Controlling Al content before molten steel solidification (S) The content can lock in the formation potential of AlN in advance, avoid the impact of aluminum content fluctuations in subsequent processes on AlN precipitation, and improve the consistency of product performance.

[0046] No complex detection methods are required; AI can be controlled. (S) The content can be indirectly controlled, simplifying process control and reducing detection costs and operational difficulties in the production process.

[0047] In some embodiments, the acid-soluble aluminum Al (S) The content of aluminum is determined by ladle testing during the continuous casting process, and aluminum loss is considered when controlling the acid-soluble aluminum content in RH refining. This aluminum loss is calculated using an empirical formula, which includes: Where t is the interval between RH outbound component detection and mid-package component detection, in minutes; α(FeTOT) The activity of FeTOT in RH slag is calculated using FactSage software.

[0048] In some embodiments, α is set (FeTOT) equal to α (氧化亚铁) and α (三氧化二铁) The sum of α (氧化亚铁) and α (三氧化二铁) The sum was calculated using FactSage software.

[0049] In some embodiments, continuous casting tundish testing can directly reflect Al (S) To ensure the actual effective content of AlN, and avoid compositional discrepancies between RH outgoing inspection and subsequent processes, the AlN content control can be made more closely aligned with actual production conditions. Through empirical formulas, the amount of aluminum lost between RH outgoing and intermediate ladle operations can be quantified, preventing Al loss due to time differences. (S) To ensure the production of the target amount of AlN, the FeTOT activity is calculated using FactSage software to accurately capture the impact of RH slag on aluminum loss, reducing errors in empirical estimations. By considering aluminum loss, the nitrogen content can be adjusted to avoid AlN being lost due to aluminum loss. (S) An imbalance in the ratio of nitrogen to phosphorus prevents insufficient AlN precipitation and avoids residual free nitrogen.

[0050] This invention also provides a production process for high magnetic induction oriented silicon steel, comprising the following steps: The high magnetic induction oriented silicon steel is obtained by converter smelting, RH furnace refining, continuous casting, hot rolling, normalizing annealing, cold rolling, decarburizing annealing, magnesium oxide coating, and high temperature annealing.

[0051] The nitrogen content in the high magnetic induction oriented silicon steel is determined according to the control method for high magnetic induction oriented silicon steel described above.

[0052] The chemical composition of the high magnetic induction oriented silicon steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) 0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

[0053] This invention also provides a high-magnetic-induction oriented silicon steel, prepared according to the above-described control method or production process for high-magnetic-induction oriented silicon steel. The composition of the high-magnetic-induction oriented silicon steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al... (S) 0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

[0054] The magnetic induction of the high magnetic induction oriented silicon steel is ≥1.9T.

[0055] In some embodiments, the size of the AlN / CuS composite inhibitor in the continuously cast billet of the high magnetic induction oriented silicon steel is ≤90 nm.

[0056] In some embodiments, the size of the AlN-CuS composite inhibitor in the hot-rolled plate of the high magnetic induction oriented silicon steel is 20 nm to 70 nm.

[0057] To further illustrate the present invention, the following examples are provided: Example 1 A method for controlling high magnetic induction grain-oriented silicon steel, comprising the following steps: S1: Molten iron and scrap steel are mixed and then smelted in a converter to obtain the first molten steel.

[0058] S2: The first molten steel is refined in an RH furnace to obtain refined molten steel. The chemical composition of the refined molten steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) 0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

[0059] The upper limit of nitrogen content is the sum of nitrogen solubility in ferrite and austenite at 1250℃. This sum is calculated using Thermo-Calc software, employing a supersaturation method. The input nitrogen content far exceeds the sum of nitrogen solubility in each phase of the steel, allowing for the calculation of nitrogen solubility in each phase under specific pressure and temperature conditions. (Acid-soluble aluminum (Al)) (S)=Suitable nitrogen content × 27 ÷ 14. The content of acid-soluble aluminum (Al(s)) is determined by ladle testing during the continuous casting process, and aluminum loss is considered when controlling the acid-soluble aluminum content in RH refining. This aluminum loss is calculated using an empirical formula, which includes: t represents the interval between RH outbound component detection and mid-package component detection, in minutes; α (FeTOT) The activity of FeTOT in RH slag is calculated using FactSage software.

[0060] S3: Refined molten steel is subjected to continuous casting, hot rolling, normalizing annealing, cold rolling, decarburizing annealing, magnesium oxide coating, and high-temperature annealing in sequence to obtain high magnetic induction oriented silicon steel.

[0061] Tests showed that the size of the AlN-CuS composite inhibitor in the continuously cast billet of 100 heats of high magnetic induction oriented silicon steel was ≤90 nm, and the size of the AlN-CuS composite inhibitor in the hot-rolled plate of high magnetic induction oriented silicon steel was 20 nm~70 nm, resulting in a magnetic induction of ≥1.9 T for the high magnetic induction oriented silicon steel.

[0062] See Figure 1 It is known that the order of phase appearance during the cooling phase transformation of high-magnetic-induction grain-oriented silicon steel is liquid phase - ferrite phase - austenite phase - precipitated phase. In the calculation, a supersaturation calculation method is used, with the input nitrogen content far exceeding the sum of the nitrogen solubility of each phase in the steel. This allows for the calculation of the nitrogen solubility of each phase in the steel under certain pressure and temperature conditions. The calculation results show that the maximum nitrogen solubility in the liquid phase is 0.0375%, in the ferrite phase it is 0.016%, and in the austenite phase it is 0.003%. The maximum nitrogen solubility in the gas phase is 0.029%, at which point the sum of the nitrogen solubility of the austenite and ferrite phases is 0.011%. This is set as the optimal nitrogen content for high-magnetic-induction grain-oriented silicon steel, ensuring sufficient AlN precipitation while preventing excessive nitrogen content from causing bubble formation. During the cooling phase transformation of high-magnetic-induction grain-oriented silicon steel, sufficient AlN phase formation must be ensured, but excessive nitrogen content must not lead to bubble formation.

[0063] Comparative Example 1 Compared to Example 1, the composition of the refined steel was changed.

[0064] The chemical composition of the refined steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) 0.023%~0.025%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

[0065] The acid-soluble aluminum content in the RH furnace was not controlled according to the method in Example 1 at the refining endpoint, resulting in fluctuations in the acid-soluble aluminum content in the tundish.

[0066] The other steps are the same as in Example 1, and high magnetic induction oriented silicon steel is obtained.

[0067] Tests showed that the size of the inhibitors in the continuous casting billets and hot-rolled plates of the high magnetic induction oriented silicon steel were significantly smaller than those in Example 1, and the number was reduced, resulting in a magnetic induction of <1.9 T for the obtained high magnetic induction oriented silicon steel.

[0068] Comparative Example 2 Compared to Example 1, the composition of the refined steel was changed.

[0069] The chemical composition of the refined steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) The composition of the alloy is 0.023%~0.025%, Cu 0.49%~0.52%, N 0.012~0.013%, with the remainder being Fe and other unavoidable impurity elements. Other steps are the same as in Example 1, resulting in high-magnetic-induction oriented silicon steel.

[0070] Tests showed that the size of the AlN-CuS composite inhibitor in the continuously cast billet of high magnetic induction silicon steel was >90 nm, and the size of the AlN-CuS composite inhibitor in the hot-rolled plate of high magnetic induction silicon steel was >70 nm, resulting in a magnetic induction of <1.9 T for the high magnetic induction silicon steel.

[0071] Comparative Example 3 Compared to Example 1, the composition of the refined steel was changed.

[0072] The chemical composition of the refined steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) The composition of the alloy is 0.015%~0.0175%, Cu 0.49%~0.52%, N 0.08%~0.09%, with the remainder being Fe and other unavoidable impurity elements. Other steps are the same as in Example 1, resulting in high-magnetic-induction oriented silicon steel.

[0073] Tests showed that the size of the inhibitors in the continuous casting billets and hot-rolled plates of the high magnetic induction oriented silicon steel were significantly smaller than those in Example 1, and the number was reduced, resulting in a magnetic induction of <1.9 T for the obtained high magnetic induction oriented silicon steel.

[0074] The aforementioned control method, production process, and resulting steel for high-magnetic-induction oriented silicon steel utilizes the blending of molten iron and scrap steel to initially control the content of elements such as C, Si, and Mn in the molten steel, providing a low-phosphorus, low-sulfur base steel for subsequent RH furnace refining. RH furnace refining allows for precise adjustment of the molten steel's chemical composition, meeting the stringent requirements of high-magnetic-induction oriented silicon steel for inhibitors (AlN, MnS). Reducing the sulfur content to below 0.012% avoids hot brittleness, improves magnetic properties, and reduces iron loss. Hot rolling promotes the solidification of inhibitors (AlN, MnS), providing sufficient inhibition for subsequent secondary recrystallization. Through the coordinated operation of each process step, the chemical composition of the refined steel is precisely controlled, solving the technical problems of difficulty in accurately controlling the nitrogen mass fraction in steel and the poor magnetic properties of existing high-magnetic-induction oriented silicon steel. Furthermore, by precisely controlling the chemical composition and grain orientation, high-magnetic-induction, low-iron-loss oriented silicon steel is ultimately obtained, meeting the demand for high-efficiency magnetic materials in electrical equipment such as transformers and motors.

[0075] Moreover, the control method of the present invention is simple and easy to operate. By effectively controlling the content of each element, iron loss is reduced and the magnetism of high magnetic induction oriented silicon steel is increased, thereby improving production efficiency and reducing production costs.

[0076] In summary, the above-described technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for controlling high magnetic induction oriented silicon steel, characterized in that the steps include... include: S1: Molten iron and scrap steel are mixed and then smelted in a converter to obtain the first molten steel; S2: Refine the first molten steel in an RH furnace to obtain refined molten steel; S3: The refined molten steel is sequentially subjected to continuous casting, hot rolling, normalizing annealing and cold rolling to obtain cold-rolled steel sheet; S4: The cold-rolled steel sheet is subjected to decarburization annealing treatment to obtain the high magnetic induction oriented silicon steel; The chemical composition of the refined steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) 0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

2. The control method for high magnetic induction oriented silicon steel according to claim 1, characterized in that, The nitrogen solubility of each phase during the cooling phase transformation of steel was calculated using Thermol-Calc software.

3. The control method for high magnetic induction oriented silicon steel according to claim 1, characterized in that, The nitrogen content of the high magnetic induction oriented silicon steel is equal to the sum of the nitrogen solubility in ferrite and austenite when nitrogen in the gas phase reaches its maximum.

4. The control method for high magnetic induction oriented silicon steel according to claim 3, characterized in that, The acid-soluble aluminum (Al) in the high magnetic induction oriented silicon steel (S) The content is equal to the nitrogen content of the high magnetic induction oriented silicon steel × 27 ÷ 14.

5. The control method for high magnetic induction oriented silicon steel according to claim 1, characterized in that, The acid-soluble aluminum Al (S) The content of aluminum is determined by ladle testing during the continuous casting process, and aluminum loss is considered when controlling the acid-soluble aluminum content in RH refining. This aluminum loss is calculated using an empirical formula, which includes: Where t is the interval between RH outbound component detection and mid-package component detection, in minutes; α (FeTOT) The activity of FeTOT in RH slag is calculated using FactSage software.

6. A production process for high magnetic induction oriented silicon steel, characterized in that, Includes the following steps: Converter smelting - RH furnace refining - continuous casting - hot rolling - normalizing annealing - cold rolling - decarburizing annealing - magnesium oxide coating - high temperature annealing, to obtain the high magnetic induction oriented silicon steel; The nitrogen content in the high magnetic induction oriented silicon steel is determined by the control method for high magnetic induction oriented silicon steel according to any one of claims 1 to 5; The chemical composition of the high magnetic induction oriented silicon steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) 0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements.

7. A high magnetic induction oriented silicon steel, as described in any one of claims 1 to 5. The high magnetic induction oriented silicon steel is obtained by the control method or the production process of claim 6, characterized in that... The composition of the high magnetic induction oriented silicon steel, by mass fraction, includes: C 0.032%~0.04%, Si 3.1%~3.25%, Mn 0.2%~0.22%, P 0%~0.012%, S 0.006%~0.012%, Al (S) 0.0175%~0.02%, Cu 0.49%~0.52%, N 0.01~0.011%, the remainder being Fe and other unavoidable impurity elements; The magnetic induction of the high magnetic induction oriented silicon steel is ≥1.9T.

8. The high magnetic induction oriented silicon steel according to claim 7, characterized in that, The size of the AlN and CuS composite inhibitor in the continuously cast billet of the high magnetic induction oriented silicon steel is ≤90 nm.

9. The high magnetic induction oriented silicon steel according to claim 7, characterized in that, The size of the AlN-CuS composite inhibitor in the hot-rolled plate of the high magnetic induction oriented silicon steel is 20 nm to 70 nm.

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