Non-oriented silicon steel composite material and preparation method thereof

Abstract

The invention discloses a non-oriented silicon steel composite material and a preparation method thereof.The method comprises the steps that powder of Ce, La and Y elements is subjected to ball milling, and ground powder with the particle size smaller than or equal to 8 micrometers is obtained; adding 0.5-1.2 wt% of nano TiO2 as a modifier into the ground powder, and uniformly depositing a rare earth composite layer on the surface of a non-oriented silicon steel substrate by adopting a magnetron sputtering method to obtain a silicon steel plate; stacking the multiple layers of silicon steel plates to form a laminated layer; zirconia sol is coated on interlayer contact surfaces of the multiple layers of silicon steel plates; standing at a preset temperature for a preset period of time, so that gelation-dehydration-inorganic conversion of the zirconium oxide sol layer is completed, and an assembled silicon steel plate is obtained; and carrying out post-treatment on the assembled silicon steel plate to obtain the non-oriented silicon steel composite material. The magnetic performance, the mechanical toughness and the low-temperature service reliability of the non-oriented silicon steel material are improved.

Description

Technical Field

[0001] This invention relates to the field of steel plate material technology, and in particular to a non-oriented silicon steel composite material and its preparation method. Background Technology

[0002] In the existing technology, a steel-magnesium alloy die-casting composite method is used to prepare composite materials that not only have good interfacial bonding force, but also excellent interfacial stability and service performance. The test results show that it has both excellent mechanical properties and vibration reduction performance, and no solid solution precipitation occurs at the magnesium / steel interface during long-term service at 200-600℃. The interfacial bonding strength gradually increases within this temperature range.

[0003] The existing method for preparing the insulating coating of electromagnetic steel plates involves precipitating a dense nano-SiO2 / TiO2 coating on the surface of silicon steel and then curing it through heat treatment. Tests show that the ceramic composite coating can effectively improve the surface hardness, wear resistance, heat resistance, and anti-sticking properties of the material, and the prepared coating has good stability and doubles the wear resistance life.

[0004] For non-oriented silicon steel composites, traditional methods using a single hot rolling or conventional annealing process are insufficient to achieve multi-level, multi-stage microstructure and performance optimization. This not only limits the thickness uniformity and surface quality of non-oriented silicon steel composites but also hinders further grain refinement and texture distribution control. Poor interfacial bonding often negatively impacts the overall performance of the composite material. Summary of the Invention

[0005] This invention provides a method for preparing non-oriented silicon steel composite materials. After introducing a rare earth composite layer, rare earth elements are easily enriched and preferentially precipitated at grain boundaries in the steel matrix. By inhibiting grain growth, promoting favorable texture orientation, and purifying grain boundary impurities, the favorable texture orientation and grain fineness are effectively improved, thereby enhancing the magnetic properties, mechanical toughness, and low-temperature service reliability of the non-oriented silicon steel material.

[0006] On one hand, the present invention provides a method for preparing a non-oriented silicon steel composite material, comprising: Powders containing Ce, La, and Y elements were ball-milled to obtain ground powder with a particle size ≤ 8 μm. 0.5–1.2 wt% of nano-TiO2 was added to the ground powder as a modifier, and a rare earth composite layer was uniformly deposited on the surface of a non-oriented silicon steel substrate by magnetron sputtering to obtain a silicon steel sheet. Multilayer silicon steel sheets are stacked to form a laminate; zirconium oxide sol is coated on the interlayer contact surfaces of the multilayer silicon steel sheets; and the laminate is left to stand at a preset temperature for a preset time to allow the zirconium oxide sol layer to complete the gelation-dehydration-inorganization transformation, thereby obtaining the assembled silicon steel sheet. The assembled silicon steel sheet is post-processed to obtain a non-oriented silicon steel composite material.

[0007] Furthermore, the mass ratio of grinding balls to powder during the ductile ironing process is 15:1, and the composition and weight percentage content of the non-oriented silicon steel sheet are: Si: 2.5~4.5 wt.%, Mn: 0.1~0.2 wt.%, C: 0.005 wt.%, Al: 0.5~1.0 wt.%, S: 0.001~0.002 wt.%, with the remainder being iron and impurities.

[0008] Furthermore, the method employing magnetron sputtering to uniformly deposit a rare earth composite layer on the surface of a non-oriented silicon steel substrate to obtain a silicon steel sheet includes: The surface oxide film of the silicon steel substrate is removed by argon ion cleaning to obtain cleaned silicon steel; the ion cleaning pressure is 5-10 Pa and the time is 10-15 min. A rare earth composite layer is uniformly deposited on the surface of the cleaned silicon steel using magnetron sputtering to obtain a silicon steel sheet. The temperature during the spraying process is controlled at 45±2℃, and the spraying spacing is 10–15cm.

[0009] Furthermore, the molar ratio of Ce, La, and Y elements in the rare earth composite layer is 2:2:1, and the thickness ratio of the rare earth composite layer to the non-oriented silicon steel substrate is 1:500.

[0010] Furthermore, the total thickness of the rare earth composite layer is 0.5-3 μm; the mass of the zirconium oxide sol between the layers is 0.1-0.3% of the mass of the multilayer silicon steel sheet.

[0011] Furthermore, the stacking of multilayer silicon steel sheets to form a laminate includes: Select 3-5 layers of silicon steel sheet, and coat the surface of each silicon steel sheet with zirconia sol to form a zirconia sol layer of less than 1μm; The step of allowing the zirconium oxide sol layer to stand at a preset temperature for a preset time to complete the gelation-dehydration-inorganic transformation, resulting in the assembled silicon steel sheet, includes: The solution is left to stand at 600±50℃ for 10±5 min to induce a preliminary interface activation reaction, so that the zirconium oxide sol layer completes the gelation-dehydration-inorganization transformation to obtain the assembled silicon steel sheet.

[0012] Further, the post-processing of the assembled silicon steel sheet to obtain a non-oriented silicon steel composite material includes: The assembled silicon steel sheet is fed into a vacuum hot press furnace, and subjected to a vacuum degree of 3×10⁻⁶. -2The hot-pressed composite steel plate was held at 900℃ and 5MPa for 70±10min to achieve metallurgical bonding and effective diffusion distribution of rare earth elements. Then it was cooled at a rate of 5℃ / min to obtain the hot-pressed composite steel plate. The hot-pressed composite steel plate is subjected to hot rolling, cold rolling and annealing treatment to obtain a non-oriented silicon steel composite material.

[0013] Further, the hot-pressed composite steel plate is subjected to hot rolling, cold rolling, and annealing treatment to obtain a non-oriented silicon steel composite material, comprising: The hot-pressed composite steel plate is hot-rolled to obtain a hot-rolled slab; the temperature is 1150±50℃, the first pass reduction rate is 40%, and the thickness gradient temperature difference is controlled to be <5℃. The hot-rolled slab is treated with laser rapid cooling technology at both ends, followed by multiple cold rolling passes, and isothermal annealing is performed between the cold rolling passes to obtain an annealed steel plate; wherein the annealing temperature is 750-900℃, the time is 20-30min, the protective atmosphere is Ar2, and the reduction rate of each cold rolling pass is 25±3%; A non-oriented silicon steel composite material is obtained from the annealed steel sheet.

[0014] Furthermore, during the cold rolling and annealing stages, an external magnetic field is applied to the hot-rolled slab and maintained for 60–180 s; the magnetic induction intensity of the magnetic field is 0.2–0.5 T, and the direction of the magnetic field is parallel to the rolling direction of the cold rolling.

[0015] Further, the process of obtaining the non-oriented silicon steel composite material from the annealed steel sheet includes: The annealed steel plate was cooled using a combined air-cooling and spray cooling technology; the air velocity was 12±5m / s, and the water droplet diameter was 50±5μm; the temperature difference between different areas of the plate after cooling was ±3℃. After cooling, the steel plate is mechanically treated to remove residual stress, so that the residual oxygen content on the surface of the steel plate is less than or equal to 0.02 wt%, thus obtaining a non-oriented silicon steel composite material.

[0016] Furthermore, the method for preparing the zirconium oxide sol includes: Using zirconium oxychloride as a zirconium source, the zirconium oxychloride is dissolved in deionized water to obtain a zirconium oxychloride solution; An acidic solution was added to the zirconium oxychloride solution to adjust the pH of the solution to 2-3, and the solution was stirred at 60-80°C for 1-2 h to form a stable zirconium oxide precursor sol. The zirconia precursor sol was aged at room temperature for 12–24 h and then filtered to remove coarse particles, resulting in a stable zirconia sol.

[0017] On the other hand, the present invention provides a non-oriented silicon steel composite material, which is prepared by the above method; the non-oriented silicon steel composite material has an elongation of ≥20% and an impact toughness of ≥85 J in a low temperature environment of -60℃, and an interlaminar separation rate of ≤2%.

[0018] The present invention has the following beneficial effects: This invention involves ball milling Ce, La, and Y element powders to obtain grinding powder with a particle size ≤8μm. 0.5–1.2 wt% nano-TiO2 is added to the grinding powder as a modifier. A rare earth composite layer is uniformly deposited on the surface of a non-oriented silicon steel substrate using magnetron sputtering to obtain a silicon steel sheet. Multiple silicon steel sheets are stacked to form a laminate. Zirconia sol is coated on the interlayer contact surfaces of the multilayer silicon steel sheets. The laminate is then left to stand at a preset temperature for a preset time to allow the zirconia sol layer to complete a gelation-dehydration-inorganization transformation, resulting in an assembled silicon steel sheet. The assembled silicon steel sheet is then post-treated to obtain a non-oriented silicon steel composite material. By introducing the rare earth composite layer, rare earth elements readily accumulate and preferentially precipitate at grain boundaries within the steel matrix. This effectively improves favorable texture orientation and grain fineness by inhibiting grain growth, promoting favorable texture orientation, and purifying grain boundary impurities, thereby significantly enhancing the strength, toughness, and low-temperature performance of the silicon steel. By introducing rare earth elements to form a multi-level composite system and combining it with magnetron sputtering, the microstructure of the composite material was effectively refined and the directional growth of favorable texture was achieved, which significantly improved the magnetic properties, mechanical toughness and low-temperature service reliability of non-oriented silicon steel materials. Attached Figure Description

[0019] To more clearly illustrate the technical solution of the present invention, 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 these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a method for preparing a non-oriented silicon steel composite material according to an embodiment of the present invention. Detailed Implementation

[0021] 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 some embodiments of the present invention, and not all embodiments. 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.

[0022] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0023] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0024] like Figure 1 As shown in the figure, this embodiment provides a method for preparing a non-oriented silicon steel composite material, the method comprising: S1. Ball mill the powders of Ce, La and Y elements to obtain ground powder with a particle size ≤ 8 μm; S2. Add 0.5–1.2 wt% nano-TiO2 as a modifier to the ground powder, and uniformly deposit a rare earth composite layer on the surface of the non-oriented silicon steel substrate by magnetron sputtering to obtain silicon steel sheet. S3. Stack the multi-layer silicon steel sheets to form a stack; coat the interlayer contact surfaces of the multi-layer silicon steel sheets with zirconium oxide sol; and let it stand at a preset temperature for a preset time to allow the zirconium oxide sol layer to complete the gelation-dehydration-inorganization transformation to obtain the assembled silicon steel sheet. S4. Post-process the assembled silicon steel sheet to obtain a non-oriented silicon steel composite material.

[0025] Compared to the traditional method of directly adding rare earth elements to molten steel, the embodiments in this specification form a rare earth composite layer on the substrate surface through processes such as layered composite formation and magnetron sputtering. This facilitates the effective diffusion and directional distribution of rare earth elements along the interface during subsequent vacuum hot pressing and multi-stage rolling. This strengthens interlayer bonding, purifies the interface, refines grains, and increases favorable texture, thereby improving the material's strength, toughness, and magnetic properties. Compared to the smelting method where rare earth elements are dispersed throughout the overall steel, the layered introduction, combined with heat treatment and external fields, promotes the active migration and local enrichment of rare earth elements, allowing them to penetrate beyond the surface layer and reach the interface and a certain thickness range. This is beneficial for microstructure control and performance improvement.

[0026] For example, the rotation speed during the spheroidizing process is 300 rpm and the time is 2 hours; the mass ratio of grinding balls to powder during the spheroidizing process is 15:1, thereby obtaining grinding powder with a particle size ≤8μm; then 0.5–1.2wt% of nano TiO2 is added to the grinding powder as a modifier. Nano TiO2 mainly acts as a modifier in the composite layer, which can inhibit the agglomeration of rare earth particles, promote the compactness and uniformity of the composite layer, refine the grains, purify the interface and enhance the bonding force with the matrix, thereby synergistically improving the mechanical and magnetic properties of the material. A rare earth composite layer is uniformly deposited on the surface of a non-oriented silicon steel substrate using magnetron sputtering to obtain silicon steel sheet. Magnetron sputtering enables dense and uniform deposition of the rare earth composite layer and effective distribution of elements on the silicon steel surface, facilitating the full diffusion of rare earths and interfacial strengthening of the silicon steel substrate during subsequent heat treatment. Therefore, it can further improve grain refinement and interlayer bonding, resulting in lower-temperature toughness and performance uniformity superior to methods such as die casting and sol-gel introduction. The composition and weight percentage of the non-oriented silicon steel sheet are as follows: Si: 2.5~4.5 wt.%, Mn: 0.1~0.2 wt.%, C: 0.005 wt.%, Al: 0.5~1.0 wt.%, S: 0.001~0.002 wt.%, with the remainder being iron and impurities.

[0027] For example, the method of uniformly depositing a rare earth composite layer on the surface of a non-oriented silicon steel substrate using magnetron sputtering to obtain a silicon steel sheet includes: The surface oxide film of the silicon steel substrate is removed by argon ion cleaning to obtain cleaned silicon steel; the ion cleaning pressure is 5-10 Pa and the time is 10-15 min. A rare earth composite layer is uniformly deposited on the surface of the cleaned silicon steel using magnetron sputtering to obtain a silicon steel sheet. The temperature during the spraying process is controlled at 45±2℃, and the spraying spacing is 10–15cm.

[0028] In the embodiments of this specification, before magnetron sputtering, argon ion cleaning can be used to remove the surface oxide film and achieve surface activation, ensuring that the coating is free of omissions and agglomeration; thus obtaining cleaned silicon steel; then, a rare earth composite layer is uniformly deposited on the surface of the cleaned silicon steel using magnetron sputtering to obtain a silicon steel sheet; the rare earth composite layer is physically vapor-deposited (PVD) by magnetron sputtering, and the temperature of the silicon steel substrate is controlled at 45±2℃ during the sputtering deposition process.

[0029] For example, the molar ratio of Ce, La, and Y elements in the rare earth composite layer is 2:2:1, and the thickness ratio of the rare earth composite layer to the non-oriented silicon steel substrate is 1:500. Although the ratio is small, this thin layer has a significant regulatory effect on the interface structure and properties. When the thickness is moderate, it is conducive to the effective diffusion of rare earth elements and interface activation. Too thin a layer will affect the modification effect, while too thick a layer may lead to brittle interlayers or stress concentration, affecting the overall performance of the material.

[0030] For example, the total thickness of the rare earth composite layer is 0.5-3 μm; the mass of the zirconium oxide sol between the layers is 0.1-0.3% of the mass of the multilayer silicon steel sheet, thereby ensuring interface purification and metallurgical bonding efficiency.

[0031] For example, the stacking of multilayer silicon steel sheets to form a laminate includes: Select 3-5 layers of silicon steel sheet, and coat the surface of each silicon steel sheet with zirconia sol to form a zirconia sol layer of less than 1μm; The step of allowing the zirconium oxide sol layer to stand at a preset temperature for a preset time to complete the gelation-dehydration-inorganic transformation, resulting in the assembled silicon steel sheet, includes: The solution is left to stand at 600±50℃ for 10±5 min to induce a preliminary interface activation reaction, so that the zirconium oxide sol layer completes the gelation-dehydration-inorganization transformation to obtain the assembled silicon steel sheet.

[0032] In the embodiments of this specification, multi-layer steel plate stacking helps to strengthen the interface and refine the particle size. However, too many layers can lead to complex processes and increased risks of interlayer bonding, while too few layers result in limited composite and control effects. For finished steel products of the same total thickness, selecting 3 to 5 layers can maximize the strength, toughness, and comprehensive performance of the material while ensuring interface stability and ease of processing. Too many or too few layers are not conducive to optimal performance. During the multi-layer stacking of steel plates, a zirconium oxide sol with a thickness of <1μm is sprayed between the layers. ZrO2 nanoparticle sol / colloidal dispersion is mainly used as an interface self-cleaning agent. Its stable existence is achieved by a small amount of acidic stabilizer (such as nitric acid) to keep the sol stable and dispersed. The mixture is then allowed to stand at 600℃ for 10 minutes to induce a preliminary interface activation reaction. The interface activation reaction is confirmed by evidence such as element diffusion and phase composition changes at the interface. The specific reaction involves standing at approximately 600°C for 10 minutes after lamination, allowing the <1μm zirconium oxide sol thin layer between the layers to complete the gelation-dehydration-inorganization transformation, volatilizing adsorbed water and residual organic matter, and weakening the continuous oxide film between the layers. This improves the interfacial wetting and actual contact area, enhances the interfacial bonding force, reduces residual oxygen at the interface, and provides a low-resistance diffusion channel for element interdiffusion and metallurgical bonding in the subsequent vacuum hot pressing stage, thus indicating that the activation reaction has occurred.

[0033] For example, the method for preparing the zirconium oxide sol includes: Using zirconium oxychloride as a zirconium source, the zirconium oxychloride is dissolved in deionized water to obtain a zirconium oxychloride solution; An acidic solution was added to the zirconium oxychloride solution to adjust the pH of the solution to 2-3, and the solution was stirred at 60-80°C for 1-2 h to form a stable zirconium oxide precursor sol. The zirconia precursor sol was aged at room temperature for 12–24 h and then filtered to remove coarse particles, resulting in a stable zirconia sol.

[0034] For example, the post-processing of the assembled silicon steel sheet to obtain a non-oriented silicon steel composite material includes: The assembled silicon steel sheet is fed into a vacuum hot press furnace, and subjected to a vacuum degree of 3×10⁻⁶. -2 The hot-pressed composite steel plate was held at 900℃ and 5MPa for 70±10min to achieve metallurgical bonding and effective diffusion distribution of rare earth elements. Then it was cooled at a rate of 5℃ / min to obtain the hot-pressed composite steel plate. The hot-pressed composite steel plate is subjected to hot rolling, cold rolling and annealing treatment to obtain a non-oriented silicon steel composite material.

[0035] In the embodiments of this specification, the assembled multilayer steel plate is fed into a vacuum hot press furnace and held at a vacuum degree of 3×10-2 Pa, a temperature of 900℃, and a pressure of 5MPa for 70 minutes to achieve metallurgical bonding and effective diffusion distribution of rare earth elements. Then, it is cooled at a rate of 5℃ / min to obtain a hot-pressed composite steel plate. The hot-pressed composite steel plate is then subjected to hot rolling, cold rolling, and annealing treatment to obtain a non-oriented silicon steel composite material.

[0036] For example, the process of hot rolling, cold rolling, and annealing the hot-pressed composite steel plate to obtain a non-oriented silicon steel composite material includes: The hot-pressed composite steel plate is hot-rolled to obtain a hot-rolled slab; the temperature is 1150±50℃, the first pass reduction rate is 40%, and the thickness gradient temperature difference is controlled to be <5℃. The hot-rolled slab is treated with laser rapid cooling technology at both ends, followed by multiple cold rolling passes, and isothermal annealing is performed between the cold rolling passes to obtain an annealed steel plate; wherein the annealing temperature is 750-900℃, the time is 20-30min, the protective atmosphere is Ar2, and the reduction rate of each cold rolling pass is 25±3%; A non-oriented silicon steel composite material is obtained from the annealed steel sheet.

[0037] This specification describes the hot rolling of multilayer steel sheets after vacuum hot pressing composite; the temperature is 1150℃, the first pass reduction is 40%, and the thickness gradient temperature difference is controlled to be <5℃; the ends of the hot-rolled slab are treated with laser rapid cooling technology to reduce end temperature stress. Isothermal annealing is used between multiple cold rolling passes; 750-900℃, 20-30min, under Ar2 protective atmosphere, with a reduction of 25±3% per cold rolling pass. In this embodiment, the annealing and rolling processes are combined with protective atmosphere treatment to achieve an inclusion content of less than 0.01 wt% and a main impurity particle size controlled within the range of 1–3 μm.

[0038] The embodiments in this specification combine laser rapid cooling at both ends during the rolling process after vacuum hot pressing, with a cooling rate greater than 25℃ / s, which significantly suppresses microcracks at the beginning and end and interlayer separation.

[0039] For example, during the cold rolling and annealing stages, an external magnetic field is applied to the hot-rolled slab and maintained for 60–180 s; the magnetic induction intensity of the magnetic field is 0.2–0.5 T, and the direction of the magnetic field is parallel to the rolling direction of the cold rolling. This promotes the growth of favorable textures and the orderly arrangement of rare earth precipitates in the material.

[0040] For example, obtaining the non-oriented silicon steel composite material from the annealed steel sheet includes: The annealed steel plate was cooled using a combined air-cooling and spray cooling technology; the air velocity was 12±5m / s, and the water droplet diameter was 50±5μm; the temperature difference between different areas of the plate after cooling was ±3℃. After cooling, the steel plate is mechanically treated to remove residual stress, so that the residual oxygen content on the surface of the steel plate is less than or equal to 0.02 wt%, thus obtaining a non-oriented silicon steel composite material.

[0041] The embodiments in this specification use a combination of air cooling and spray rapid cooling (air speed 12 m / s, water droplet diameter 50 μm, plate temperature difference ±3℃, good uniformity). After cooling, mechanical treatment is performed to remove residual stress, and the surface residual oxygen content is not higher than 0.02 wt%.

[0042] This invention involves ball milling Ce, La, and Y element powders to obtain grinding powder with a particle size ≤8μm. 0.5–1.2 wt% nano-TiO2 is added to the grinding powder as a modifier. A rare earth composite layer is uniformly deposited on the surface of a non-oriented silicon steel substrate using magnetron sputtering to obtain a silicon steel sheet. Multiple silicon steel sheets are stacked to form a laminate. Zirconia sol is coated on the interlayer contact surfaces of the multilayer silicon steel sheets. The laminate is then left to stand at a preset temperature for a preset time to allow the zirconia sol layer to complete a gelation-dehydration-inorganization transformation, resulting in an assembled silicon steel sheet. The assembled silicon steel sheet is then post-treated to obtain a non-oriented silicon steel composite material. By introducing the rare earth composite layer, rare earth elements readily accumulate and preferentially precipitate at grain boundaries within the steel matrix. This effectively improves favorable texture orientation and grain fineness by inhibiting grain growth, promoting favorable texture orientation, and purifying grain boundary impurities, thereby significantly enhancing the strength, toughness, and low-temperature performance of the silicon steel. By introducing rare earth elements to form a multi-level composite system and combining it with magnetron sputtering, the microstructure of the composite material was effectively refined and the directional growth of favorable texture was achieved, which significantly improved the magnetic properties, mechanical toughness and low-temperature service reliability of non-oriented silicon steel materials.

[0043] This specification describes embodiments that, through the infiltration of rare earth elements into silicon steel and combined with nano-modification, form a stable multi-layered system, and improve interfacial bonding by incorporating zirconium oxide sol. Vacuum hot pressing, laser rapid cooling, and magnetron sputtering processes are employed to enhance the strength and toughness of the non-oriented silicon steel composite material; wherein {001} <120> λ and {111} <112> The proportion of γ-oriented texture was significantly improved (of which component {110} <001> (λ) and {111} <112> The volume fractions of (γ) are denoted as λ% and γ%, respectively. According to the experimental results, λ+γ≥28%, which significantly improves the interlayer bonding stability and low-temperature resistance.

[0044] In this embodiment, non-oriented silicon steel composite materials were prepared by traditional die casting, sol-gel method and magnetron sputtering method of this embodiment, respectively, and the performance was tested at an extreme low temperature of -60℃. The performance comparison table is shown in Table 1 below. The traditional die-casting process is as follows: 1. Raw materials and proportions (1) Matrix composition (wt%): Si: 2.5–4.5, Mn: 0.1–0.2, C: 0.005, Al: 0.5–1.0, S: 0.001–0.002, balance Fe and unavoidable impurities.

[0045] 2. Equipment and Tooling (1) Vacuum induction melting furnace (VIM) or equivalent clean melting equipment (2) Casting / slab mold (slab example: 120 mm × 120 mm × 30 mm) (3) Vacuum hot press, hot rolling mill, cold rolling mill, annealing furnace (Ar2 protection), magnetic field loading device, composite rapid cooling device, straightening equipment.

[0046] 3. Process flow and operating conditions 3.1 Smelting and Alloying (1) Material preparation and weighing: Weigh electrolytic iron, ferrosilicon, ferromanganese, aluminum granules, etc. according to the target composition. (2) Vacuuming and melting: Vacuum the furnace to ≤5 Pa, heat up to 1600±10℃, and keep it warm until the melt is uniform and clear.

[0047] (3) Deoxygenation and composition correction: Add Al particles in the range of 0.5–1.0 wt%, and keep warm for 2 min to complete deoxygenation and homogenization.

[0048] (4) Casting and forming: The casting temperature is 1550±10℃ to obtain a slab, which is then air-cooled to room temperature.

[0049] 3.2 Homogenization of Cast Billets and Preparation for Drafting (1) Homogenization treatment: 1200℃×2 h, furnace cooled to about 900℃ before being taken out of the furnace, to provide uniformity of structure and composition for subsequent hot processing.

[0050] 3.3 Laminated Composite and Subsequent Processing (1) Sample shearing and stacking: The plates from the same batch were sheared into single-layer sheets of 120 mm × 120 mm × 1.0 mm; 3 layers were stacked (total thickness approximately 3 mm).

[0051] (2) Vacuum hot pressing composite: vacuum degree 3×10⁻2 Pa, 900℃, pressure 5 MPa, heat preservation for 70 min, cooling at 5℃ / min.

[0052] (3) Hot rolling: 1150℃ for initial rolling; first pass reduction rate of 40% and thickness gradient temperature difference <5℃.

[0053] (4) Cold rolling + inter-pass annealing: the cold rolling reduction rate is 25±3% per pass, and the inter-pass isothermal annealing is 800℃×25 min, with Ar2 protection.

[0054] (5) Magnetic field assistance: magnetic induction intensity 0.35 T, direction parallel to rolling direction, for 120 s.

[0055] (6) Rapid cooling and straightening: air cooling, straightening to relieve stress.

[0056] The sol-gel process is as follows (raw materials and proportions, equipment and apparatus are the same as those used in the traditional die-casting method): 1. Sol preparation (1) Mixing and dispersing: Mix the nitrate solution, silica sol and ethanol according to the formula.

[0057] (2) Mechanical stirring: 30 min; followed by ultrasonic dispersion for 20 min to make the system uniform.

[0058] (3) Aging: Aging at room temperature for 12 h in a sealed environment to obtain a stable coating sol.

[0059] 2. Substrate pretreatment and surface activation (1) Cleaning: Wipe with acetone → rinse with deionized water → dry with hot air.

[0060] (2) Light acid washing and activation: 3% H2SO4, 80–85℃×10 s, water washing and drying.

[0061] 3. Coating, drying, gelling and curing (1) Dip coating: Dip for 60 s, pull up at 50 mm / min, dry at 80℃ for 10 min after each coating, repeat 3 times to accumulate film thickness.

[0062] (2) Gelation: 150℃×20 min to promote gel network formation and solvent removal.

[0063] (3) Short-time high-temperature curing / densification: 850℃×30 s (800–950℃, 10–100 s are optional ranges; 850℃×30 s is taken as an example) to form a composite coating.

[0064] (4) Coating target: thickness of approximately 0.8–2.0 μm (0.5–3 μm is feasible), and the surface should be continuous without obvious missed coating or large-area agglomeration.

[0065] 4. Laminated composite (1) Sample shearing and stacking: The same specification plate is sheared into a single layer of 120 mm × 120 mm × 1.0 mm; 3 layers are stacked.

[0066] (2) Vacuum hot pressing composite: vacuum degree 2.3×10⁻² Pa, 950℃, pressure 7 MPa, heat preservation for 90 min, cooling at 10℃ / min.

[0067] Table 1 As can be seen, the final product of the non-oriented silicon steel composite material prepared in this embodiment can pass the extreme low temperature impact and tensile test at -60℃, with an elongation of ≥20%, impact toughness ≥85 J, interlaminar separation rate ≤2%, and preferred texture orientation ratio ≥28%. The overall performance is superior to that of non-oriented silicon steel materials prepared by traditional die casting or sol-gel methods.

[0068] This embodiment also provides a non-oriented silicon steel composite material, which is prepared by the above method; the non-oriented silicon steel composite material has an elongation of ≥20% and an impact toughness of ≥85 J in a low temperature environment of -60℃, and an interlaminar separation rate of ≤2%.

[0069] The following specific embodiments illustrate the preparation method of the non-oriented silicon steel composite material of the present invention.

[0070] Example 1 This invention provides a method for preparing a non-oriented silicon steel composite material, comprising: Powders containing Ce, La, and Y elements were ball-milled to obtain grinding powder with a particle size ≤ 8 μm. During the ball milling process, the mass ratio of grinding balls to powder was 15:1, the rotation speed was 300 rpm, and the time was 2 hours. The surface oxide film of the silicon steel substrate was removed by argon ion cleaning to obtain cleaned silicon steel; the ion cleaning pressure was 5 Pa and the time was 15 min; the composition and weight percentage of the non-oriented silicon steel sheet were Si: 2.5 wt.%, Mn: 0.2 wt.%, C: 0.005 wt.%, Al: 0.5 wt.%, S: 0.001 wt.%, with the remainder being iron and impurities.

[0071] A rare earth composite layer was uniformly deposited on the surface of the cleaned silicon steel using magnetron sputtering to obtain a silicon steel sheet. The spraying temperature was controlled at 43℃, and the spraying spacing was 10cm. The molar ratio of Ce, La, and Y elements in the rare earth composite layer was 2:2:1, the thickness ratio of the rare earth composite layer to the non-oriented silicon steel substrate was 1:500, and the total thickness of the rare earth composite layer was 0.5μm. The mass of the zirconium oxide sol between the layers was 0.1% of the mass of the multilayer silicon steel sheet.

[0072] Using zirconium oxychloride as a zirconium source, the zirconium oxychloride is dissolved in deionized water to obtain a zirconium oxychloride solution; An acidic solution was added to the zirconium oxychloride solution to adjust the pH of the solution to 2, and the solution was stirred at 60°C for 2 h to form a stable zirconium oxide precursor sol. The zirconia precursor sol was aged at room temperature for 12 hours and then filtered to remove coarse particles, resulting in a stable zirconia sol.

[0073] Select a 3-layer silicon steel sheet, and coat the surface of each silicon steel sheet with zirconia sol to form a zirconia sol layer of less than 1 μm; The solution is left to stand at 600℃ for 10 minutes to induce a preliminary interface activation reaction, so that the zirconia sol layer completes the gelation-dehydration-inorganization transformation to obtain the assembled silicon steel sheet.

[0074] The assembled silicon steel sheet is fed into a vacuum hot press furnace, and subjected to a vacuum degree of 3×10⁻⁶. -2 The hot-pressed composite steel plate was held at 900℃ and 5MPa for 60 minutes to achieve metallurgical bonding and effective diffusion distribution of rare earth elements. Then it was cooled at a rate of 5℃ / min to obtain the hot-pressed composite steel plate. The hot-pressed composite steel plate is hot-rolled to obtain a hot-rolled slab; the temperature is 1100℃, the first pass reduction rate is 40%, and the thickness gradient temperature difference is controlled to be <5℃. The hot-rolled slab is treated with laser rapid cooling technology at both ends, followed by multiple cold rolling passes, and isothermal annealing is performed between the cold rolling passes to obtain an annealed steel plate; wherein the annealing temperature is 750℃, the time is 30min, the protective atmosphere is Ar2, and the reduction rate of each cold rolling pass is 22%; During the cold rolling and annealing stages, an external magnetic field is applied to the hot-rolled slab and maintained for 60 seconds; the magnetic induction intensity of the magnetic field is 0.5T, and the direction of the magnetic field is parallel to the rolling direction of the cold rolling.

[0075] The annealed steel plate was cooled using a combined air-cooling and spray cooling technology; the air velocity was 12 m / s and the water droplet diameter was 45 μm; the temperature difference between different areas of the plate after cooling was ±3℃. After cooling, the steel plate is mechanically treated to remove residual stress, so that the residual oxygen content on the surface of the steel plate is less than or equal to 0.02 wt%, thus obtaining a non-oriented silicon steel composite material.

[0076] The non-oriented silicon steel composite material obtained in this embodiment has an elongation of 20% and an impact toughness of 85 J at a low temperature of -60℃, and an interlaminar separation rate of 2%.

[0077] Example 2 This invention provides a method for preparing a non-oriented silicon steel composite material, comprising: Powders containing Ce, La, and Y elements were ball-milled to obtain grinding powder with a particle size ≤ 8 μm. During the ball milling process, the mass ratio of grinding balls to powder was 15:1, the rotation speed was 300 rpm, and the time was 2 hours. The surface oxide film of the silicon steel substrate was removed by argon ion cleaning to obtain cleaned silicon steel; the ion cleaning pressure was 10 Pa and the time was 15 min; the composition and weight percentage of the non-oriented silicon steel sheet were Si: 4.5 wt.%, Mn: 0.1 wt.%, C: 0.005 wt.%, Al: 1.0 wt.%, S: 0.002 wt.%, with the remainder being iron and impurities.

[0078] A rare earth composite layer was uniformly deposited on the surface of the cleaned silicon steel using magnetron sputtering to obtain a silicon steel sheet. The spraying temperature was controlled at 47℃, and the spraying spacing was 15cm. The molar ratio of Ce, La, and Y in the rare earth composite layer was 2:2:1, and the thickness ratio of the rare earth composite layer to the non-oriented silicon steel substrate was 1:500. The total thickness of the rare earth composite layer was 3μm; the mass of the zirconium oxide sol between the layers was 0.3% of the mass of the multilayer silicon steel sheet.

[0079] Using zirconium oxychloride as a zirconium source, the zirconium oxychloride is dissolved in deionized water to obtain a zirconium oxychloride solution; An acidic solution was added to the zirconium oxychloride solution to adjust the pH of the solution to 3, and the solution was stirred at 80°C for 1 h to form a stable zirconium oxide precursor sol. The zirconia precursor sol was aged at room temperature for 24 h and then filtered to remove coarse particles, resulting in a stable zirconia sol.

[0080] Five layers of silicon steel sheet are selected, and zirconia sol is coated on the surface of each layer of silicon steel sheet to form a zirconia sol layer of less than 1 μm. The solution is left to stand at 650°C for 15 minutes to induce a preliminary interface activation reaction, so that the zirconia sol layer completes the gelation-dehydration-inorganization transformation to obtain the assembled silicon steel sheet.

[0081] The assembled silicon steel sheet is fed into a vacuum hot press furnace, and subjected to a vacuum degree of 3×10⁻⁶. -2 The hot-pressed composite steel plate was held at 900℃ and 5MPa for 80 minutes to achieve metallurgical bonding and effective diffusion distribution of rare earth elements. Then it was cooled at a rate of 5℃ / min to obtain the hot-pressed composite steel plate. The hot-pressed composite steel plate is hot-rolled to obtain a hot-rolled slab; the temperature is 1200℃, the first pass reduction rate is 40%, and the thickness gradient temperature difference is controlled to be <5℃. The hot-rolled slab is treated with laser rapid cooling technology at both ends, followed by multiple cold rolling passes, and isothermal annealing is performed between the cold rolling passes to obtain an annealed steel plate; wherein the annealing temperature is 900℃, the time is 20min, the protective atmosphere is Ar2, and the reduction rate of each cold rolling pass is 28%; During the cold rolling and annealing stages, an external magnetic field is applied to the hot-rolled slab and maintained for 180 seconds; the magnetic induction intensity of the magnetic field is 0.2T, and the direction of the magnetic field is parallel to the rolling direction of the cold rolling.

[0082] The annealed steel plate was cooled using a combined air-cooling and spray cooling technology; the air velocity was 17 m / s and the water droplet diameter was 55 μm; the temperature difference between different areas of the plate after cooling was ±3℃. After cooling, the steel plate is mechanically treated to remove residual stress, so that the residual oxygen content on the surface of the steel plate is less than or equal to 0.02 wt%, thus obtaining a non-oriented silicon steel composite material.

[0083] The non-oriented silicon steel composite material obtained in this embodiment has an elongation of 22%, an impact toughness of 97 J, and an interlaminar separation rate of 1.8% at a low temperature of -60℃.

[0084] Example 3 This invention provides a method for preparing a non-oriented silicon steel composite material, comprising: Powders containing Ce, La, and Y elements were ball-milled to obtain grinding powder with a particle size ≤ 8 μm. During the ball milling process, the mass ratio of grinding balls to powder was 15:1, the rotation speed was 300 rpm, and the time was 2 hours. The surface oxide film of the silicon steel substrate was removed by argon ion cleaning to obtain cleaned silicon steel; the ion cleaning pressure was 8 Pa and the time was 12 min; the composition and weight percentage of the non-oriented silicon steel sheet were Si: 3.2 wt.%, Mn: 0.18 wt.%, C: 0.005 wt.%, Al: 0.7 wt.%, S: 0.0017 wt.%, with the remainder being iron and impurities.

[0085] A rare earth composite layer was uniformly deposited on the surface of the cleaned silicon steel using magnetron sputtering to obtain a silicon steel sheet. The spraying temperature was controlled at 45℃, and the spraying spacing was 13cm. The molar ratio of Ce, La, and Y elements in the rare earth composite layer was 2:2:1, and the thickness ratio of the rare earth composite layer to the non-oriented silicon steel substrate was 1:500. The total thickness of the rare earth composite layer was 2μm; the mass of the zirconium oxide sol between the layers was 0.2% of the mass of the multilayer silicon steel sheet.

[0086] Using zirconium oxychloride as a zirconium source, the zirconium oxychloride is dissolved in deionized water to obtain a zirconium oxychloride solution; An acidic solution was added to the zirconium oxychloride solution to adjust the pH of the solution to 2, and the solution was stirred at 70°C for 1.5 h to form a stable zirconium oxide precursor sol. The zirconia precursor sol was aged at room temperature for 18 hours and then filtered to remove coarse particles, resulting in a stable zirconia sol.

[0087] Four layers of silicon steel sheet are selected, and zirconium oxide sol is coated on the surface of each layer of silicon steel sheet to form a zirconium oxide sol layer of less than 1 μm. The solution is left to stand at 600℃ for 12 minutes to induce a preliminary interface activation reaction, so that the zirconia sol layer completes the gelation-dehydration-inorganization transformation to obtain the assembled silicon steel sheet.

[0088] The assembled silicon steel sheet is fed into a vacuum hot press furnace, and subjected to a vacuum degree of 3×10⁻⁶. -2 The hot-pressed composite steel plate was held at 900℃ and 5MPa for 72 minutes to achieve metallurgical bonding and effective diffusion distribution of rare earth elements. Then it was cooled at a rate of 5℃ / min to obtain the hot-pressed composite steel plate. The hot-pressed composite steel plate is hot-rolled to obtain a hot-rolled slab; the temperature is 1170℃, the first pass reduction rate is 40%, and the thickness gradient temperature difference is controlled to be <5℃. The hot-rolled slab is treated with laser rapid cooling technology at both ends, followed by multiple cold rolling passes, and isothermal annealing is performed between the cold rolling passes to obtain an annealed steel plate; wherein the annealing temperature is 850℃, the time is 25min, the protective atmosphere is Ar2, and the reduction rate of each cold rolling pass is 26%; During the cold rolling and annealing stages, an external magnetic field is applied to the hot-rolled slab and maintained for 90 seconds; the magnetic induction intensity of the magnetic field is 0.4T, and the direction of the magnetic field is parallel to the rolling direction of the cold rolling.

[0089] The annealed steel plate was cooled using a combined air-cooling and spray cooling technology; the air velocity was 17 m / s and the water droplet diameter was 52 μm; the temperature difference between different areas of the plate after cooling was ±3℃. After cooling, the steel plate is mechanically treated to remove residual stress, so that the residual oxygen content on the surface of the steel plate is less than or equal to 0.02 wt%, thus obtaining a non-oriented silicon steel composite material.

[0090] The non-oriented silicon steel composite material obtained in this embodiment has an elongation of 30% and an impact toughness of 90 J at a low temperature of -60℃, and an interlaminar separation rate of 1.5%.

[0091] Example 4 This invention provides a method for preparing a non-oriented silicon steel composite material, comprising: Powders containing Ce, La, and Y elements were ball-milled to obtain grinding powder with a particle size ≤ 8 μm. During the ball milling process, the mass ratio of grinding balls to powder was 15:1, the rotation speed was 300 rpm, and the time was 2 hours. The surface oxide film of the silicon steel substrate was removed by argon ion cleaning to obtain cleaned silicon steel; the ion cleaning pressure was 9 Pa and the time was 14 min; the composition and weight percentage of the non-oriented silicon steel sheet were Si: 3.5 wt.%, Mn: 0.7 wt.%, C: 0.005 wt.%, Al: 0.8 wt.%, S: 0.0018 wt.%, with the remainder being iron and impurities.

[0092] A rare earth composite layer was uniformly deposited on the surface of the cleaned silicon steel using magnetron sputtering to obtain a silicon steel sheet. The spraying temperature was controlled at 46℃, and the spraying spacing was 13cm. The molar ratio of Ce, La, and Y in the rare earth composite layer was 2:2:1, and the thickness ratio of the rare earth composite layer to the non-oriented silicon steel substrate was 1:500. The total thickness of the rare earth composite layer was 2μm; the mass of the zirconium oxide sol between the layers was 0.25% of the mass of the multilayer silicon steel sheet.

[0093] Using zirconium oxychloride as a zirconium source, the zirconium oxychloride is dissolved in deionized water to obtain a zirconium oxychloride solution; An acidic solution was added to the zirconium oxychloride solution to adjust the pH of the solution to 2, and the solution was stirred at 75°C for 1.8 h to form a stable zirconium oxide precursor sol. The zirconia precursor sol was aged at room temperature for 20 hours and then filtered to remove coarse particles, resulting in a stable zirconia sol.

[0094] Select 3-5 layers of silicon steel sheet, and coat the surface of each silicon steel sheet with zirconia sol to form a zirconia sol layer of less than 1μm; The solution is left to stand at 550°C for 13 minutes to induce a preliminary interface activation reaction, so that the zirconium oxide sol layer completes the gelation-dehydration-inorganization transformation to obtain the assembled silicon steel sheet.

[0095] The assembled silicon steel sheet is fed into a vacuum hot press furnace, and subjected to a vacuum degree of 3×10⁻⁶. -2 The hot-pressed composite steel plate was held at 900℃ and 5MPa for 78 minutes to achieve metallurgical bonding and effective diffusion distribution of rare earth elements. Then it was cooled at a rate of 5℃ / min to obtain the hot-pressed composite steel plate. The hot-pressed composite steel plate is hot-rolled to obtain a hot-rolled slab; the temperature is 1180℃, the first pass reduction rate is 40%, and the thickness gradient temperature difference is controlled to be <5℃. The hot-rolled slab is treated with laser rapid cooling technology at both ends, followed by multiple cold rolling passes, and isothermal annealing is performed between the cold rolling passes to obtain an annealed steel plate; wherein the annealing temperature is 830℃, the time is 28min, the protective atmosphere is Ar2, and the reduction rate of each cold rolling pass is 27%; During the cold rolling and annealing stages, an external magnetic field is applied to the hot-rolled slab and maintained for 100 seconds; the magnetic induction intensity of the magnetic field is 0.45T, and the direction of the magnetic field is parallel to the rolling direction of the cold rolling.

[0096] The annealed steel plate was cooled using a combined air-cooling and spray cooling technology; the air velocity was 12 m / s and the water droplet diameter was 55 μm; the temperature difference between different areas of the plate after cooling was ±3℃. After cooling, the steel plate is mechanically treated to remove residual stress, so that the residual oxygen content on the surface of the steel plate is less than or equal to 0.02 wt%, thus obtaining a non-oriented silicon steel composite material.

[0097] The non-oriented silicon steel composite material obtained in this embodiment has an elongation of 25% and an impact toughness of 88 J at a low temperature of -60℃, and an interlaminar separation rate of 1.6%.

[0098] This invention involves ball milling Ce, La, and Y element powders to obtain grinding powder with a particle size ≤8μm. 0.5–1.2 wt% nano-TiO2 is added to the grinding powder as a modifier. A rare earth composite layer is uniformly deposited on the surface of a non-oriented silicon steel substrate using magnetron sputtering to obtain a silicon steel sheet. Multiple silicon steel sheets are stacked to form a laminate. Zirconia sol is coated on the interlayer contact surfaces of the multilayer silicon steel sheets. The laminate is then left to stand at a preset temperature for a preset time to allow the zirconia sol layer to complete a gelation-dehydration-inorganization transformation, resulting in an assembled silicon steel sheet. The assembled silicon steel sheet is then post-treated to obtain a non-oriented silicon steel composite material. By introducing the rare earth composite layer, rare earth elements readily accumulate and preferentially precipitate at grain boundaries within the steel matrix. This effectively improves favorable texture orientation and grain fineness by inhibiting grain growth, promoting favorable texture orientation, and purifying grain boundary impurities, thereby significantly enhancing the strength, toughness, and low-temperature performance of the silicon steel. By introducing rare earth elements to form a multi-level composite system and combining it with magnetron sputtering, the microstructure of the composite material was effectively refined and the directional growth of favorable texture was achieved, which significantly improved the magnetic properties, mechanical toughness and low-temperature service reliability of non-oriented silicon steel materials.

[0099] The above-disclosed embodiments are merely a few preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing a non-oriented silicon steel composite material, characterized in that, The method includes: Powders containing Ce, La, and Y elements were ball-milled to obtain ground powder with a particle size ≤ 8 μm. 0.5–1.2 wt% of nano-TiO2 was added to the ground powder as a modifier, and a rare earth composite layer was uniformly deposited on the surface of a non-oriented silicon steel substrate by magnetron sputtering to obtain a silicon steel sheet. Multilayer silicon steel sheets are stacked to form a laminate; zirconium oxide sol is coated on the interlayer contact surfaces of the multilayer silicon steel sheets; and the laminate is left to stand at a preset temperature for a preset time to allow the zirconium oxide sol layer to complete the gelation-dehydration-inorganization transformation, thereby obtaining the assembled silicon steel sheet. The assembled silicon steel sheet is post-processed to obtain a non-oriented silicon steel composite material.

2. The method according to claim 1, characterized in that, In the ductile ironing process, the mass ratio of grinding balls to powder is 15:

1. The composition and weight percentage content of the non-oriented silicon steel sheet are as follows: Si: 2.5~4.5 wt.%, Mn: 0.1~0.2 wt.%, C: 0.005 wt.%, Al: 0.5~1.0 wt.%, S: 0.001~0.002 wt.%, with the remainder being iron and impurities.

3. The method according to claim 1, characterized in that, The process employs magnetron sputtering to uniformly deposit a rare earth composite layer on the surface of a non-oriented silicon steel substrate to obtain a silicon steel sheet, comprising: The surface oxide film of the silicon steel substrate is removed by argon ion cleaning to obtain cleaned silicon steel; the ion cleaning pressure is 5-10 Pa and the time is 10-15 min. A rare earth composite layer is uniformly deposited on the surface of the cleaned silicon steel using magnetron sputtering to obtain a silicon steel sheet. The temperature during the spraying process is controlled at 45±2℃, and the spraying spacing is 10–15cm.

4. The method according to claim 1, characterized in that, The molar ratio of Ce, La, and Y elements in the rare earth composite layer is 2:2:1, and the thickness ratio of the rare earth composite layer to the non-oriented silicon steel substrate is 1:

500.

5. The method according to claim 4, characterized in that, The total thickness of the rare earth composite layer is 0.5-3 μm; the mass of the zirconium oxide sol between the layers is 0.1-0.3% of the mass of the multilayer silicon steel sheet.

6. The method according to any one of claims 1-5, characterized in that, The stacking of multi-layer silicon steel sheets to form a laminate includes: Select 3-5 layers of silicon steel sheet, and coat the surface of each silicon steel sheet with zirconia sol to form a zirconia sol layer of less than 1μm; The step of allowing the zirconium oxide sol layer to stand at a preset temperature for a preset time to complete the gelation-dehydration-inorganic transformation, resulting in the assembled silicon steel sheet, includes: The solution is left to stand at 600±50℃ for 10±5 min to induce a preliminary interface activation reaction, so that the zirconium oxide sol layer completes the gelation-dehydration-inorganization transformation to obtain the assembled silicon steel sheet.

7. The method according to claim 1, characterized in that, The post-processing of the assembled silicon steel sheet to obtain a non-oriented silicon steel composite material includes: The assembled silicon steel sheet is fed into a vacuum hot press furnace, and subjected to a vacuum degree of 3×10⁻⁶. -2 The hot-pressed composite steel plate was held at 900℃ and 5MPa for 70±10min to achieve metallurgical bonding and effective diffusion distribution of rare earth elements. Then it was cooled at a rate of 5℃ / min to obtain the hot-pressed composite steel plate. The hot-pressed composite steel plate is subjected to hot rolling, cold rolling and annealing treatment to obtain a non-oriented silicon steel composite material.

8. The method according to claim 7, characterized in that, The hot-pressed composite steel plate is subjected to hot rolling, cold rolling, and annealing treatment to obtain a non-oriented silicon steel composite material, comprising: The hot-pressed composite steel plate is hot-rolled to obtain a hot-rolled slab; the temperature is 1150±50℃, the first pass reduction rate is 40%, and the thickness gradient temperature difference is controlled to be <5℃. The hot-rolled slab is treated with laser rapid cooling technology at both ends, followed by multiple cold rolling passes, and isothermal annealing is performed between the cold rolling passes to obtain an annealed steel plate; wherein the annealing temperature is 750-900℃, the time is 20-30min, the protective atmosphere is Ar2, and the reduction rate of each cold rolling pass is 25±3%; A non-oriented silicon steel composite material is obtained from the annealed steel sheet.

9. The method according to claim 8, characterized in that, During the cold rolling and annealing stages, an external magnetic field is applied to the hot-rolled slab and maintained for 60–180 s; the magnetic induction intensity of the magnetic field is 0.2–0.5 T, and the direction of the magnetic field is parallel to the rolling direction of the cold rolling.

10. The method according to claim 8, characterized in that, The non-oriented silicon steel composite material obtained from the annealed steel sheet includes: The annealed steel plate was cooled using a combined air-cooling and spray cooling technology; the air velocity was 12±5 m / s, and the water droplet diameter was 50±5 μm; the temperature difference between different areas of the plate after cooling was ±3℃. After cooling, the steel plate is mechanically treated to remove residual stress, so that the residual oxygen content on the surface of the steel plate is less than or equal to 0.02 wt%, thus obtaining a non-oriented silicon steel composite material.

11. The method according to claim 1, characterized in that, The method for preparing the zirconium oxide sol includes: Using zirconium oxychloride as a zirconium source, the zirconium oxychloride is dissolved in deionized water to obtain a zirconium oxychloride solution; An acidic solution was added to the zirconium oxychloride solution to adjust the pH of the solution to 2-3, and the solution was stirred at 60-80°C for 1-2 hours to form a stable zirconium oxide precursor sol. The zirconia precursor sol was aged at room temperature for 12–24 h and then filtered to remove coarse particles, resulting in a stable zirconia sol.

12. A non-oriented silicon steel composite material, characterized in that, The non-oriented silicon steel composite material is prepared by any one of claims 1 to 11; the non-oriented silicon steel composite material has an elongation of ≥20%, an impact toughness of ≥85 J, and an interlaminar separation rate of ≤2% at a low temperature of -60℃.

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