A method for preparing high-silicon non-oriented silicon steel with strong cubic texture

Abstract

This invention belongs to the field of non-oriented silicon steel preparation technology, specifically relating to a method for preparing high-silicon non-oriented silicon steel with a strong cubic texture. The invention uses hot-rolled sheet with a Si content of 3.4–3.7 wt.% as raw material, and employs a process of normalizing, controlled-direction cold rolling, and crystallization annealing. By using controlled-direction rolling to create an angle between the cold and hot rolling directions, the initial texture before cold rolling is altered, resulting in a strong "rotational Gaussian texture" in the sheet before cold rolling. After controlled-direction cold rolling and annealing, a strong cubic texture is produced, thereby obtaining high-silicon non-oriented silicon steel with high magnetic induction.

Description

Technical Field

[0001] This invention belongs to the field of non-oriented silicon steel preparation technology, specifically relating to a method for preparing high-silicon non-oriented silicon steel with a strong cubic texture. Background Technology

[0002] Non-oriented silicon steel is a soft magnetic material with very low carbon content, mainly used in the manufacture of various motor cores. It is a very important functional metal material in power electronic systems, and its magnetic properties (iron loss, magnetic induction) directly affect the energy consumption and efficiency of the motor. Currently, driven by energy conservation, new energy vehicles are developing rapidly. With the rapid iteration of new energy vehicle technology, the drive motor, as a core component of new energy vehicles, faces increasingly higher performance requirements, needing to possess advantages such as high speed, miniaturization, high torque, high strength, and high efficiency. Therefore, the non-oriented silicon steel used in drive motor cores also needs to meet higher requirements: thin profiles, high magnetic induction, low iron loss, and high strength, to simultaneously meet the needs of new energy vehicles for comfort, energy consumption, and safety.

[0003] To improve motor power density and ensure safe operation at high speeds, non-oriented silicon steel focuses on three key characteristics: iron loss, magnetic flux density, and strength. Lower iron loss results in lower energy consumption; higher magnetic flux density leads to greater motor torque and higher efficiency; and higher strength allows the motor to withstand greater centrifugal stress at high speeds, resulting in a higher safety factor. Therefore, the technological development of non-oriented silicon steel requires achieving lower iron loss, higher magnetic flux density, and higher strength, as well as a better balance among these three characteristics.

[0004] Silicon (Si) is the main strengthening element in non-oriented silicon steel. Increasing the Si content can achieve high strength and effectively reduce iron loss. However, excessive Si content reduces the cold workability of the sheet, and since Si is a non-magnetic element, high content significantly worsens the magnetic properties. Conversely, reducing thickness can also effectively reduce iron loss, but it increases texture strength, which is detrimental to magnetic properties, further deteriorating the magnetic properties. Both of these factors make high-silicon non-oriented silicon steel unable to meet the evolving technological requirements of new energy vehicle drive motors. Therefore, while increasing strength and reducing iron loss through high silicon content and thinning, it is urgent to address the issue of low magnetic properties in thin-gauge high-silicon non-oriented silicon steel. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for preparing a strong cubic textured high silicon non-oriented silicon steel, wherein the strong cubic textured thin-gauge high silicon non-oriented silicon steel prepared by the present invention has high magnetic induction.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing high-silicon non-oriented silicon steel with a strong cubic texture, comprising the following steps:

[0008] After homogenization heat treatment, silicon steel alloy ingots are hot rolled to obtain hot-rolled plates.

[0009] The hot-rolled sheet is subjected to normalizing treatment to obtain normalized sheet;

[0010] The normalized sheet is subjected to a first cold rolling process to obtain a first cold-rolled sheet;

[0011] The first cold rolling is either a first conventional cold rolling or a first controlled-direction cold rolling;

[0012] The first controlled cold rolling is as follows: before the first cold rolling, the normalized plate is cut at an angle of 20-60° to the hot rolling direction;

[0013] The first cold-rolled sheet is subjected to a first annealing to obtain a first annealed sheet;

[0014] The first annealed sheet is subjected to a second cold rolling process to obtain a second cold-rolled sheet.

[0015] The second cold rolling is either a second conventional cold rolling or a second controlled-direction cold rolling;

[0016] The second controlled cold rolling is as follows: before the second cold rolling, the first annealed sheet is cut at an angle of 25-60° to the first cold rolling direction, either counterclockwise or clockwise.

[0017] At least one controlled cold rolling process is performed in the first cold rolling and the second cold rolling;

[0018] The second cold-rolled sheet is subjected to a second annealing to obtain a high-silicon non-oriented silicon steel with a strong cubic texture.

[0019] The high-silicon non-oriented silicon steel with strong cubic texture comprises the following elemental composition by weight percentage:

[0020] Si: 3.4~3.7 wt.%, Al: 0.7~1.10 wt.%, Mn: 0.2~0.55 wt.%, balance being Fe and unavoidable impurity elements.

[0021] Preferably, the homogenization heat treatment temperature is 1100~1200℃, and the holding time is 230~240min.

[0022] Preferably, the hot rolling temperature is 800~850℃; the thickness of the hot-rolled sheet is 2.3mm.

[0023] Preferably, the normalizing treatment temperature is 850~950℃, and the holding time is 2~5min.

[0024] Preferably, the reduction of the first conventional cold rolling or the first controlled cold rolling is 70-85%.

[0025] Preferably, the reduction of the second conventional cold rolling or the second controlled cold rolling is 30-55%.

[0026] Preferably, the temperature of the first annealing is 930~980℃, and the holding time is 70~90s.

[0027] Preferably, the temperature of the second annealing is 930~980℃, and the holding time is 70~90s.

[0028] Preferably, the thickness of the first cold-rolled sheet is 0.45~0.65mm.

[0029] Preferably, the thickness of the second cold-rolled sheet is 0.3 mm.

[0030] This invention provides a method for preparing high-silicon non-oriented silicon steel with a strong cubic texture, comprising the following steps: homogenizing a silicon steel alloy ingot with heat treatment, followed by hot rolling to obtain a hot-rolled sheet; normalizing the hot-rolled sheet to obtain a normalized sheet; subjecting the normalized sheet to a first cold rolling to obtain a first cold-rolled sheet; the first cold rolling is either a first conventional cold rolling or a first controlled-direction cold rolling; the first controlled-direction cold rolling involves cutting the normalized sheet at an angle of 20-60° counterclockwise or clockwise to the hot rolling direction before the first cold rolling; subjecting the first cold-rolled sheet to a first annealing to obtain a first annealed sheet; and subjecting the first annealed sheet to a second cold rolling to obtain a second cold-rolled sheet. The second cold rolling is either a second conventional cold rolling or a second controlled cold rolling; the second controlled cold rolling is as follows: before the second cold rolling, the first annealed sheet is cut at an angle of 25~60° counterclockwise or clockwise to the first cold rolling direction; controlled cold rolling is performed at least once in the first cold rolling and the second cold rolling; the second cold-rolled sheet is subjected to a second annealing to obtain a strong cubic texture high silicon non-oriented silicon steel; the strong cubic texture high silicon non-oriented silicon steel includes the following elemental composition by weight percentage: Si: 3.4~3.7wt.%, Al: 0.7~1.10wt.%, Mn: 0.2~0.55wt.%, with the balance being Fe and unavoidable impurity elements.

[0031] This invention employs controlled rolling instead of conventional rolling. Before cold rolling, the sheet material is cut at a certain angle to the hot rolling direction, creating an angle between the cold and hot rolling directions. This results in a relatively large proportion of "rotational Gaussian texture" in the microstructure. After controlled cold rolling thinning, numerous shear bands are generated within the deformed rotational Gaussian grains, exhibiting a stable cubic orientation. These bands can form cubic crystals, serving as nucleation seeds in the subsequent recrystallization process, ultimately forming the desired cubic texture. Because the cubic texture has two easily magnetized [grains] within the rolled surface... <100> The orientation is the ideal texture for improving magnetic properties. Therefore, this invention improves the magnetic properties of high-silicon thin-gauge non-oriented silicon steel by constructing a strong cubic texture, thereby obtaining high-silicon non-oriented silicon steel with high magnetic induction. Attached Figure Description

[0032] Figure 1 A schematic diagram illustrating the preparation of a high-silicon non-oriented silicon steel with a strong cubic texture according to an embodiment of the present invention;

[0033] Figure 2 This is a flowchart illustrating the method for preparing high-silicon non-oriented silicon steel with a strong cubic texture according to an embodiment of the present invention.

[0034] Figure 3 for Typical cross-sectional orientation and fiber texture diagram;

[0035] Figure 4 The images show the macroscopic texture of the high-silicon non-oriented silicon steel with strong cubic texture prepared in Example 1 of the present invention and the non-oriented silicon steel after conventional rolling and annealing in Comparative Example 1. Detailed Implementation

[0036] This invention provides a method for preparing high-silicon non-oriented silicon steel with a strong cubic texture, comprising the following steps:

[0037] After homogenization heat treatment, silicon steel alloy ingots are hot rolled to obtain hot-rolled plates.

[0038] The hot-rolled sheet is subjected to normalizing treatment to obtain normalized sheet;

[0039] The normalized sheet is subjected to a first cold rolling process to obtain a first cold-rolled sheet;

[0040] The first cold rolling is either a first conventional cold rolling or a first controlled-direction cold rolling;

[0041] The first controlled cold rolling is as follows: before the first cold rolling, the normalized plate is cut at an angle of 20-60° to the hot rolling direction;

[0042] The first cold-rolled sheet is subjected to a first annealing to obtain a first annealed sheet;

[0043] The first annealed sheet is subjected to a second cold rolling process to obtain a second cold-rolled sheet.

[0044] The second cold rolling is either a second conventional cold rolling or a second controlled-direction cold rolling;

[0045] The second controlled cold rolling is as follows: before the second cold rolling, the first annealed sheet is cut at an angle of 25-60° to the first cold rolling direction, either counterclockwise or clockwise.

[0046] At least one controlled cold rolling process is performed in the first cold rolling and the second cold rolling;

[0047] The second cold-rolled sheet is subjected to a second annealing to obtain a high-silicon non-oriented silicon steel with a strong cubic texture.

[0048] The high-silicon non-oriented silicon steel with strong cubic texture comprises the following elemental composition by weight percentage:

[0049] Si: 3.4~3.7 wt.%, Al: 0.7~1.10 wt.%, Mn: 0.2~0.55 wt.%, balance being Fe and unavoidable impurity elements.

[0050] Unless otherwise specified, the present invention does not have special requirements on the source of the raw materials used in the preparation, and commercially available products well known to those skilled in the art can be used.

[0051] This invention involves hot rolling a silicon steel alloy ingot after homogenization heat treatment to obtain a hot-rolled sheet.

[0052] In this invention, the silicon steel alloy ingot preferably comprises the following elemental composition by weight percentage:

[0053] Si: 3.4~3.7 wt.%, Al: 0.7~1.10 wt.%, Mn: 0.2~0.55 wt.%, with the balance being impurity elements; more preferably, Si: 3.4~3.6 wt.%, Al: 0.7~1.0 wt.%, Mn: 0.3~0.5 wt.%, with the balance being Fe and unavoidable impurity elements; the impurity elements preferably include C, P, S, Cr, Ti and N; the texture of the hot-rolled silicon steel alloy plate is preferably mainly Gaussian texture and brass texture on the surface, and mainly a strong α-fiber and γ-fiber deformation texture in the central layer.

[0054] In this invention, the method for preparing the silicon steel alloy ingot preferably includes the following steps:

[0055] After mixing the raw materials according to the proportions of each group, they are melted, refined and cast in sequence to obtain silicon steel alloy ingots.

[0056] In this invention, the melting temperature is preferably 1665°C, the refining temperature is preferably 1605°C, the refining time is preferably 40 min, and the equipment used for casting is preferably a continuous casting machine.

[0057] In this invention, the temperature of the homogenization heat treatment is preferably 1100~1200℃, more preferably 1100℃, and the holding time is preferably 230~240min, more preferably 230min.

[0058] Homogenization heat treatment can eliminate internal stress in materials, improve the inhomogeneity of the microstructure, and prevent fractures caused by high Si content.

[0059] In this invention, the hot rolling temperature is preferably 800~850℃, more preferably 830℃; the thickness of the hot-rolled sheet is preferably 2.3mm. This invention does not specifically limit the hot rolling direction; any hot rolling direction well-known in the art can be used.

[0060] After obtaining the hot-rolled sheet, the present invention performs normalization treatment on the hot-rolled sheet to obtain normalized sheet.

[0061] In this invention, the normalizing temperature is preferably 850~950℃, more preferably 860℃, and the holding time is preferably 2~5min, more preferably 3min; the normalizing treatment is preferably carried out under a protective gas; the protective gas preferably includes hydrogen and nitrogen; the volume fraction of hydrogen in the protective gas is preferably 25%, and the volume fraction of nitrogen is preferably 75%.

[0062] This invention adjusts the grain size of the sheet material before cold rolling and improves its cold working performance through normalization treatment.

[0063] After obtaining the normalized sheet, the present invention performs a first cold rolling on the normalized sheet to obtain a first cold-rolled sheet.

[0064] In this invention, the first cold rolling is a first conventional cold rolling or a first controlled cold rolling, preferably the first controlled cold rolling; the first controlled cold rolling is: before the first cold rolling, the normalized plate is cut at an angle of 20~60° to the hot rolling direction, preferably 25~55°.

[0065] In this invention, the reduction of the first conventional cold rolling is preferably 70-85%, more preferably 76.1%; the first conventional cold rolling is preferably 4 passes; and the equipment used for the first conventional cold rolling is preferably a Sendzimir 20-roll mill.

[0066] In this invention, the reduction of the first controlled cold rolling is preferably 70-85%, more preferably 76.1%; the number of passes of the first controlled cold rolling is preferably 4 passes; and the equipment used for the first controlled cold rolling is preferably a Sendzimir 20-roll mill.

[0067] In this invention, the thickness of the first cold-rolled sheet is preferably 0.45~0.65mm, more preferably 0.55mm.

[0068] After obtaining the first cold-rolled sheet, the present invention performs a first annealing on the first cold-rolled sheet to obtain a first annealed sheet.

[0069] In this invention, the temperature of the first annealing is preferably 930~980℃, more preferably 960℃, and the holding time is preferably 70~90s, more preferably 90s; the first annealing is preferably carried out under a protective gas; the protective gas preferably includes hydrogen and nitrogen; the volume fraction of hydrogen in the protective gas is preferably 25%, and the volume fraction of nitrogen is preferably 75%.

[0070] In this invention, the first annealing can improve the grain size before the second stage of cold rolling, which coarsens the microstructure of the cold-rolled sheet in the second stage, forms more shear bands, and optimizes the recrystallization texture and magnetic properties.

[0071] After obtaining the first annealed plate, the present invention performs a second cold rolling on the first annealed plate to obtain a second cold-rolled plate.

[0072] In this invention, the second cold rolling is a second conventional cold rolling or a second controlled cold rolling, preferably the second controlled cold rolling; the second controlled cold rolling is: before the second cold rolling, the first annealed sheet is cut at an angle of 25~60° to the first cold rolling direction, preferably 30~55°; at least one controlled cold rolling is performed in the first cold rolling and the second cold rolling.

[0073] In this invention, the reduction of the second conventional cold rolling is preferably 30-55%, more preferably 45.5%; the number of passes of the second conventional cold rolling is preferably 2 passes; and the equipment used for the second conventional cold rolling is preferably a Sendzimir 20-roll mill.

[0074] In this invention, the reduction of the second controlled cold rolling is preferably 30-55%, more preferably 45.5%; the number of passes of the second controlled cold rolling is preferably 2 passes; and the equipment used for the second controlled cold rolling is preferably a Sendzimir 20-roll mill.

[0075] In this invention, the thickness of the second cold-rolled sheet is preferably 0.3 mm.

[0076] This invention utilizes a staged cold rolling process to reduce the reduction in a single cold rolling cycle, accumulating a large total reduction to avoid excessive stress and cold rolling cracking in high-silicon non-oriented silicon steel. After annealing, controlled rolling replaces conventional rolling. Before cold rolling, the sheet is cut at an angle to the hot rolling direction, creating an angle between the cold and hot rolling directions. This results in a relatively large proportion of "rotational Gaussian texture" in the microstructure. The deformation of the rotated Gaussian grains after controlled cold rolling thinning generates numerous shear bands with a stable cubic orientation, capable of forming cubic crystals. These serve as nucleation seeds in the subsequent recrystallization process, ultimately forming the desired cubic texture. Because the cubic texture has two easily magnetized areas within the rolled surface… <100> The orientation is the ideal texture for improving magnetic properties. Therefore, this invention improves the magnetic properties of high-silicon thin-gauge non-oriented silicon steel by constructing a strong cubic texture, thereby obtaining high-silicon non-oriented silicon steel with high magnetic induction.

[0077] After obtaining the second cold-rolled sheet, the present invention performs a second annealing on the second cold-rolled sheet to obtain a high-silicon non-oriented silicon steel with a strong cubic texture.

[0078] In this invention, the temperature of the second annealing is preferably 930~980℃, more preferably 960℃, and the holding time is preferably 70~90s, more preferably 90s; the second annealing is preferably carried out under a protective gas; the protective gas preferably includes hydrogen and nitrogen; the volume fraction of hydrogen in the protective gas is preferably 25%, and the volume fraction of nitrogen is preferably 75%.

[0079] The role of the second annealing in this invention is that during the annealing process, non-oriented silicon steel will undergo recrystallization at grain boundaries and within grains, which increases its grain size, improves grain boundary clarity, and reduces internal defects, thereby changing its magnetic and mechanical properties.

[0080] In this invention, the strongly cubic textured high-silicon non-oriented silicon steel comprises the following elemental components by weight percentage:

[0081] Si: 3.4~3.7 wt.%, Al: 0.7~1.10 wt.%, Mn: 0.2~0.55 wt.%, balance being Fe and unavoidable impurity elements, more preferably Si: 3.4~3.6 wt.%, Al: 0.7~1.0 wt.%, Mn: 0.3~0.5 wt.%, balance being Fe and unavoidable impurity elements.

[0082] In this invention, the impurity elements include unavoidable elements such as C, P, S, Cr, Ti, and N.

[0083] Figure 1 This is a schematic diagram illustrating the preparation of a strongly cubic textured high-silicon non-oriented silicon steel according to an embodiment of the present invention. Figure 1It is known that before the first cold rolling, the present invention cuts the sheet material at a 55° angle counterclockwise to the hot rolling direction, then performs a cold rolling, and then performs a second cold rolling (conventional cold rolling).

[0084] Figure 2 This is a flowchart illustrating a method for preparing highly cubic textured high-silicon non-oriented silicon steel according to an embodiment of the present invention. Figure 2 As can be seen, the present invention involves normalizing a hot-rolled sheet of non-oriented silicon steel with a Si content of 3.4~3.7 wt.%, then performing a first conventional cold rolling or controlled directional cold rolling to a thickness of 0.45~0.65 mm, followed by a first annealing, then a second conventional cold rolling or controlled directional cold rolling to a thickness of 0.3 mm, and finally a second annealing.

[0085] Terminology Explanation:

[0086] Weight percentage: The percentage of a certain alloy component by mass (weight) out of the total mass.

[0087] Texture: During the formation of crystals, such as during the hot and cold working and plastic forming of metal materials, the grains in polycrystalline materials will arrange themselves in an orderly manner along certain directions, exhibiting more or less statistical non-uniform distribution, that is, they will aggregate and arrange themselves in certain directions, thus the probability of orientation in these directions is significantly increased. This phenomenon is called preferred orientation, or texture.

[0088] ODF diagram: Three-dimensional orientation distribution function, which quantitatively represents the spatial distribution of grain orientation in textured materials.

[0089] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0090] Example 1

[0091] The raw material composition is as follows: Si: 3.45 wt.%, Al: 0.75 wt.%, Mn: 0.5 wt.%, with the remainder being Fe and unavoidable impurity elements such as C, P, S, Cr, Ti, and N;

[0092] After mixing the raw materials according to the proportions of each group, melting them at 1665℃, refining them at 1605℃ for 40 minutes, and then casting them into ingots using a continuous casting machine to obtain silicon steel alloy ingots.

[0093] The silicon steel alloy ingot was homogenized and heat-treated at 1100℃ for 230 minutes, and then hot-rolled at 830℃ to obtain a hot-rolled plate with a thickness of 2.3 mm.

[0094] The hot-rolled sheet was normalized at 860°C for 3 minutes under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). The normalized sheet was then cut at a 55° counterclockwise angle to the hot-rolling direction and subjected to a first controlled cold rolling process using a Sendzimir 20-roll mill with a reduction of 76.1% to obtain a first cold-rolled sheet with a thickness of 0.55 mm.

[0095] The first cold-rolled sheet was subjected to a first annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). Then, the annealed first cold-rolled sheet was directly subjected to a second conventional cold rolling process using a Sendzimir 20-roll mill, with a reduction of 45.5%, to obtain a second cold-rolled sheet with a thickness of 0.3 mm. Finally, the second cold-rolled sheet was subjected to a second annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume) to obtain a high-silicon non-oriented silicon steel with a strong cubic texture.

[0096] Example 2

[0097] The raw material composition is as follows: Si: 3.45 wt.%, Al: 0.75 wt.%, Mn: 0.5 wt.%, with the remainder being Fe and unavoidable impurity elements such as C, P, S, Cr, Ti, and N;

[0098] After mixing the raw materials according to the proportions of each group, melting them at 1665℃, refining them at 1605℃ for 40 minutes, and then casting them into ingots using a continuous casting machine to obtain silicon steel alloy ingots.

[0099] The silicon steel alloy ingot was homogenized and heat-treated at 1100℃ for 230 minutes, and then hot-rolled at 830℃ to obtain a hot-rolled plate with a thickness of 2.3 mm.

[0100] The hot-rolled sheet was normalized at 860°C for 3 minutes under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). Then, the normalized sheet was subjected to a first conventional cold rolling process using a Sendzimir 20-roll mill with a reduction of 76.1% to obtain a first cold-rolled sheet with a thickness of 0.55 mm.

[0101] The first cold-rolled sheet was subjected to a first annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). The resulting first annealed sheet was then cut at a 55° counterclockwise angle to the first conventional cold rolling direction. After that, it was subjected to a second controlled cold rolling using a Sendzimir 20-roll mill with a reduction of 45.5%, resulting in a second cold-rolled sheet with a thickness of 0.3 mm. Finally, the second cold-rolled sheet was subjected to a second annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume) to obtain a high-silicon non-oriented silicon steel with a strong cubic texture.

[0102] Example 3

[0103] The raw material composition is as follows: Si: 3.45 wt.%, Al: 0.75 wt.%, Mn: 0.5 wt.%, with the remainder being Fe and unavoidable impurity elements such as C, P, S, Cr, Ti, and N;

[0104] After mixing the raw materials according to the proportions of each group, melting them at 1665℃, refining them at 1605℃ for 40 minutes, and then casting them into ingots using a continuous casting machine to obtain silicon steel alloy ingots.

[0105] The silicon steel alloy ingot was homogenized and heat-treated at 1100℃ for 230 minutes, and then hot-rolled at 830℃ to obtain a hot-rolled plate with a thickness of 2.3 mm.

[0106] The hot-rolled sheet was normalized at 860°C for 3 minutes under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). The normalized sheet was then cut at a 25° counterclockwise angle to the hot-rolling direction and subjected to a first controlled cold rolling process using a Sendzimir 20-roll mill with a reduction of 76.1% to obtain a first cold-rolled sheet with a thickness of 0.55 mm.

[0107] The first cold-rolled sheet was subjected to a first annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). The resulting first annealed sheet was cut at a 30° counterclockwise angle to the first directional cold rolling process. Then, it was subjected to a second directional cold rolling process using a Sendzimir 20-roll mill with a reduction of 45.5%, resulting in a second cold-rolled sheet with a thickness of 0.3 mm. Finally, the second cold-rolled sheet was subjected to a second annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume) to obtain a high-silicon non-oriented silicon steel with a strong cubic texture.

[0108] Example 4

[0109] The raw material composition is as follows: Si: 3.45 wt.%, Al: 0.75 wt.%, Mn: 0.5 wt.%, with the remainder being Fe and unavoidable impurity elements such as C, P, S, Cr, Ti, and N;

[0110] After mixing the raw materials according to the proportions of each group, melting them at 1665℃, refining them at 1605℃ for 40 minutes, and then casting them into ingots using a continuous casting machine to obtain silicon steel alloy ingots.

[0111] The silicon steel alloy ingot was homogenized and heat-treated at 1100℃ for 230 minutes, and then hot-rolled at 830℃ to obtain a hot-rolled plate with a thickness of 2.3 mm.

[0112] The hot-rolled sheet was normalized at 860°C for 3 minutes under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). The normalized sheet was then cut at a 55° counterclockwise angle to the hot-rolling direction and subjected to a first controlled cold rolling process using a Sendzimir 20-roll mill with a reduction of 76.1% to obtain a first cold-rolled sheet with a thickness of 0.55 mm.

[0113] The first cold-rolled sheet was subjected to a first annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). The resulting first annealed sheet was then cut at a 55° clockwise angle along the first directional cold rolling direction and subjected to a second directional cold rolling using a Sendzimir 20-roll mill with a reduction of 45.5% to obtain a second cold-rolled sheet with a thickness of 0.3 mm. Finally, the second sheet was subjected to a second annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume) to obtain a high-silicon non-oriented silicon steel with a strong cubic texture.

[0114] Comparative Example 1 (Conventional Rolling)

[0115] The raw material composition is as follows: Si: 3.45 wt.%, Al: 0.75 wt.%, Mn: 0.5 wt.%, with the remainder being Fe and unavoidable impurity elements such as C, P, S, Cr, Ti, and N;

[0116] After mixing the raw materials according to the proportions of each group, melting them at 1665℃, refining them at 1605℃ for 40 minutes, and then casting them into ingots using a continuous casting machine to obtain silicon steel alloy ingots.

[0117] The silicon steel alloy ingot was homogenized and heat-treated at 1100℃ for 230 minutes, and then hot-rolled at 830℃ to obtain a hot-rolled plate with a thickness of 2.3 mm.

[0118] The hot-rolled sheet was normalized at 860°C for 3 minutes under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). The normalized sheet was then subjected to a first conventional cold rolling process using a Sendzimir 20-roll mill with a reduction of 76.1% to obtain a first cold-rolled sheet with a thickness of 0.55 mm.

[0119] The first cold-rolled sheet was subjected to a first annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume). The resulting first annealed sheet was then subjected to a second conventional cold rolling using a Sendzimir 20-roll mill with a reduction of 45.5%, yielding a second cold-rolled sheet with a thickness of 0.3 mm. Finally, the second cold-rolled sheet was subjected to a second annealing at 960°C for 90 seconds under a protective gas (a mixture of 25% hydrogen and 75% nitrogen by volume) to obtain high-silicon non-oriented silicon steel.

[0120] Texture test

[0121] (1) The present invention uses The ODF cross-sectional diagrams were used to study the texture type and strength of high-silicon non-oriented silicon steel with a strong cubic texture. For example... Figure 3 As shown.

[0122] Three incomplete pole figures, {110}, {200}, and {211}, in the range of α polar angles from 0 to 75° were measured using an X-ray diffractometer (XRD, Bruker D8 Discover) equipped with Co Kα radiation. Then, the series expansion method proposed by Bunge was applied. I max =22, meaning the maximum value of the series is 22. Processing these pole figures yields the orientation distribution functions (ODFs) of non-oriented silicon steel. Among these, the most important ODF section for studying the macroscopic texture of non-oriented silicon steel is... ° cross section ( Figure 3 Here, the orientation density is distributed along a line in the orientation space (called fiber texture), which can indicate the type and strength of the non-oriented silicon steel texture.

[0123] (2) The textures of the high-silicon non-oriented silicon steel with strong cubic texture prepared in Example 1 and the high-silicon non-oriented silicon steel prepared in Comparative Example 1 (conventional rolling) were tested, and the results are as follows: Figure 4 As shown, Figure (a) shows the texture of the non-oriented silicon steel after annealing in Comparative Example 1 (conventional rolling), and Figure (b) shows the texture of the high-silicon non-oriented silicon steel with strong cubic texture prepared in Example 1.

[0124] Depend on Figure 4 As can be seen from the macroscopic texture diagram, the texture of the finished annealed plate (a) of Comparative Example 1 (conventional rolling) consists of a strong α The texture consists of a strong cubic texture and a relatively weak γ-fiber texture, and contains a certain amount of Gaussian texture and a very weak cubic texture; the texture of the finished annealed plate (b) prepared in Example (1) is mainly composed of a strong cubic texture and a relatively weak Gaussian texture, and also contains a certain amount of α-fiber texture. By comparison, it can be seen that high-silicon non-oriented silicon steel with a strong cubic texture can be obtained by controlled rolling.

[0125] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a high-silicon non-oriented silicon steel with a strong cubic texture, characterized in that, Includes the following steps: After homogenization heat treatment, silicon steel alloy ingots are hot rolled to obtain hot-rolled plates. The hot-rolled sheet is subjected to normalizing treatment to obtain normalized sheet; The normalized sheet is subjected to a first cold rolling process to obtain a first cold-rolled sheet; The first cold rolling is either a first conventional cold rolling or a first controlled-direction cold rolling; The first controlled cold rolling is as follows: before the first cold rolling, the normalized plate is cut at an angle of 20-60° to the hot rolling direction; The first cold-rolled sheet is subjected to a first annealing to obtain a first annealed sheet; The first annealed sheet is subjected to a second cold rolling process to obtain a second cold-rolled sheet. The second cold rolling is either a second conventional cold rolling or a second controlled-direction cold rolling; The second controlled cold rolling is as follows: before the second cold rolling, the first annealed plate is cut at an angle of 25 to 60 degrees to the first cold rolling direction, either counterclockwise or clockwise. At least one controlled cold rolling process is performed in the first cold rolling and the second cold rolling; The second cold-rolled sheet is subjected to a second annealing to obtain a high-silicon non-oriented silicon steel with a strong cubic texture. The high-silicon non-oriented silicon steel with strong cubic texture comprises the following elemental composition by weight percentage: Si: 3.4~3.7 wt.%, Al: 0.7~1.10 wt.%, Mn: 0.2~0.55 wt.%, balance being Fe and unavoidable impurity elements; The reduction of the first conventional cold rolling or the first controlled cold rolling is independently 70~85%; The reduction amount of the second conventional cold rolling or the second controlled cold rolling is independently 30~55%.

2. The preparation method according to claim 1, characterized in that, The homogenization heat treatment is performed at a temperature of 1100~1200℃ and for a holding time of 230~240min.

3. The preparation method according to claim 1, characterized in that, The hot rolling temperature is 800~850℃; the thickness of the hot-rolled sheet is 2.3mm.

4. The preparation method according to claim 1, characterized in that, The normalization treatment temperature is 850~950℃, and the holding time is 2~5min.

5. The preparation method according to claim 1, characterized in that, The temperature of the first annealing is 930~980℃, and the holding time is 70~90s.

6. The preparation method according to claim 1, characterized in that, The second annealing temperature is 930~980℃, and the holding time is 70~90s.

7. The preparation method according to claim 1, characterized in that, The thickness of the first cold-rolled sheet is 0.45~0.65mm.

8. The preparation method according to claim 1, characterized in that, The thickness of the second cold-rolled sheet is 0.3 mm.

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