Preparation method of non-oriented high silicon steel, non-oriented high silicon steel and application

Abstract

The invention discloses a preparation method of non-oriented high silicon steel, the non-oriented high silicon steel and application, the method comprises the following steps: performing ultrasonic treatment on an initial alloy melt obtained by smelting mixed raw materials at a preset distance below the liquid level of the initial alloy melt to obtain the alloy melt subjected to ultrasonic treatment; the ratio of the preset distance to the depth of the initial alloy melt is larger than or equal to 1 / 10, the ultrasonic treatment duration is 30-40 s, the ultrasonic treatment frequency is 15-20 kHz, and the ultrasonic treatment power is determined based on the depth of the alloy melt; the alloy melt is subjected to ultrasonic treatment at the position away from the bottom of the alloy melt by a preset distance, and target alloy melt is obtained; and carrying out subsequent treatment on the target alloy melt to obtain the non-oriented high silicon steel. The non-oriented high silicon steel comprises the following components in percentage by mass: 5.0%-6.5% of silicon, less than or equal to 0.005% of carbon, 0.10%-0.25% of manganese, less than or equal to 0.03% of phosphorus, less than or equal to 0.005% of sulfur and the balance of iron and inevitable impurities. The prepared non-oriented high silicon steel can improve material plasticity and magnetic performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal material preparation, in particular to a preparation method of non-oriented high-silicon steel, non-oriented high-silicon steel and application. BACKGROUND

[0002] High-silicon steel generally refers to silicon steel with a silicon content of more than 4.5wt%, and in particular high-silicon steel with a silicon content of 6.5wt% has excellent soft magnetic properties such as high magnetic permeability, high magnetic flux density, high resistivity, extremely low high-frequency iron loss and near-zero magnetostriction, and has good application prospects. However, the traditional powder metallurgy process of non-oriented silicon steel has significant deficiencies in the control of impurities, inclusions and grain boundary oxides, and as the silicon content increases, the material grain becomes coarse, the inclusion content is high, the brittleness of the silicon steel sheet increases, the magnetic loss becomes high, and thus the stability of the finished product is insufficient, which restricts the development of high-silicon steel. SUMMARY

[0003] In view of the above problems of the prior art, the present application discloses a preparation method of non-oriented high-silicon steel, non-oriented high-silicon steel and application, which can reduce the risk of cracks during rolling and improve the plasticity and magnetic properties of non-oriented high-silicon steel material. The technical solution of the present application is as follows: According to one aspect of the present application, a preparation method of non-oriented high-silicon steel is provided, comprising: melting the mixed raw materials to obtain an initial alloy melt; the mixed raw materials include iron, silicon, carbon, manganese, phosphorus and sulfur; ultrasonic treatment is performed on the initial alloy melt at a preset distance below the liquid surface of the initial alloy melt to obtain an ultrasonic treated alloy melt; the ratio between the preset distance and the depth of the initial alloy melt is greater than or equal to 1 / 10, the ultrasonic treatment time is 30s-40s, the ultrasonic treatment frequency is 15kHz-20kHz, and the ultrasonic treatment power is determined based on the depth of the alloy melt; in the case where the depth of the initial alloy melt is less than or equal to a first depth threshold, the power is 800W-1000W; in the case where the depth of the initial alloy melt is greater than the first depth threshold and less than or equal to a second depth threshold, the power is 1600W-2000W; ultrasonic treatment is performed on the ultrasonic treated alloy melt at the preset distance from the bottom of the ultrasonic treated alloy melt to obtain a target alloy melt; casting the target alloy melt, and sequentially performing forging, hot rolling, normalizing treatment, primary annealing, pickling, cold rolling and secondary annealing treatment to obtain the non-oriented high silicon steel; the non-oriented high silicon steel comprises the following mass percentage components: silicon is 5.0% to 6.5%, carbon is less than or equal to 0.005%, manganese is 0.10% to 0.25%, phosphorus is less than or equal to 0.03%, sulfur is less than or equal to 0.005%, and the rest is iron and inevitable impurities.

[0004] Optionally, the initial alloy melt is subjected to ultrasonic treatment at a preset distance below the liquid surface of the initial alloy melt to obtain an ultrasonic treated alloy melt, and the ultrasonic treated alloy melt comprises: In the case that the initial alloy melt is stable, the ultrasonic probe is inserted into the initial alloy melt at a preset temperature to a preset distance below the liquid surface of the initial alloy melt to perform ultrasonic treatment on the initial alloy melt, and the ultrasonic treated alloy melt is obtained.

[0005] Optionally, the ultrasonic probe comprises a first ultrasonic probe and a second ultrasonic probe, and the first ultrasonic probe and the second ultrasonic probe are respectively inserted into the initial alloy melt at a preset distance below the liquid surface of the initial alloy melt during ultrasonic treatment.

[0006] Optionally, the material of the ultrasonic probe is stainless steel coated with a titanium nitride plating film, silicon nitride or niobium alloy.

[0007] Optionally, the grain size of the non-oriented high silicon steel is 15 microns to 30 microns.

[0008] Optionally, the preset distance is greater than or equal to 20 mm.

[0009] Optionally, the primary annealing treatment is performed in a hydrogen atmosphere, the secondary annealing treatment is performed in an inert gas atmosphere, the temperature of the primary annealing treatment is higher than the temperature of the secondary annealing treatment, and the inert gas is nitrogen or argon.

[0010] Optionally, the target alloy melt is cast, and sequentially subjected to forging, hot rolling, normalizing treatment, primary annealing, pickling, cold rolling and secondary annealing treatment to obtain the non-oriented high silicon steel material, and the non-oriented high silicon steel material comprises: The target alloy melt is cast and subjected to forging treatment, and hot rolled to a first target thickness to obtain a hot rolled silicon steel material; The hot rolled silicon steel material is sequentially subjected to normalizing treatment, primary annealing and pickling treatment, and cold rolled to a second target thickness to obtain a cold rolled silicon steel material; The cold rolled silicon steel material is subjected to secondary annealing treatment to obtain the non-oriented high silicon steel.

[0011] According to another aspect of the disclosed embodiments of the present invention, a non-oriented high-silicon steel is provided, which is prepared by the method described in any of the above-mentioned embodiments.

[0012] According to another aspect of the disclosed embodiments of the present invention, an application of non-oriented high-silicon steel is provided, wherein the non-oriented high-silicon steel is used as a core material, and the non-oriented high-silicon steel is prepared by the method described in any of the preceding embodiments.

[0013] The method for preparing non-oriented high-silicon steel provided by this invention has the following technical advantages: This invention involves melting mixed raw materials to obtain an initial alloy melt; the mixed raw materials include iron, silicon, carbon, manganese, phosphorus, and sulfur; the initial alloy melt is ultrasonically treated at a predetermined distance below the surface to obtain an ultrasonically treated alloy melt; the ratio between the predetermined distance and the depth of the initial alloy melt is greater than or equal to 1 / 10, the ultrasonic treatment duration is 30s~40s, the ultrasonic treatment frequency is 15kHz~20kHz, and the ultrasonic treatment power is determined based on the depth of the alloy melt. When the depth of the initial alloy melt is less than or equal to a first depth threshold, the power is 800W~1000W; when the depth of the initial alloy melt is greater than the first depth threshold, and... When the depth is less than or equal to the second depth threshold, the power is 1600W~2000W; the ultrasonically treated alloy melt is ultrasonically treated at a preset distance from the bottom of the ultrasonically treated alloy melt to obtain the target alloy melt; the target alloy melt is cast and then subjected to forging, hot rolling, normalizing, first annealing, pickling, cold rolling and second annealing in sequence to obtain non-oriented high silicon steel; the non-oriented high silicon steel includes the following mass percentage components: silicon 5.0%~6.5%, carbon less than or equal to 0.005%, manganese 0.10%~0.25%, phosphorus less than or equal to 0.03%, sulfur less than or equal to 0.005%, and the remainder is iron and unavoidable impurities.

[0014] Therefore, ultrasonic treatment is performed during the melting of non-oriented high-silicon steel to refine the grains and strengthen precipitation. By optimizing the processing parameters, the plasticity and magnetic properties of the material are synergistically improved, reducing the risk of cracking during rolling and improving the strength and plasticity of non-oriented high-silicon steel, thus obtaining a high-silicon steel material that is corrosion-resistant, easy to process, and has excellent magnetic properties.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0017] Figure 1 FIG. 1 is a flowchart of a method for preparing a non-oriented high-silicon steel according to an exemplary embodiment. DETAILED DESCRIPTION

[0018] In order for those skilled in the art to better understand the technical solutions disclosed in the present application, the technical solutions in the disclosed embodiments of the present application will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort fall within the scope of protection of the present application.

[0019] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or server including a series of steps or units does not necessarily have to include only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product, or device.

[0020] For the purpose of the following detailed description, it should be understood that the present application can employ various alternative changes and order of steps unless specifically stated otherwise. In addition, unless otherwise indicated in any operational example or otherwise indicated, all numbers expressing amounts of components, as used in the specification and claims, are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending on the desired properties sought to be obtained by the present application. At least, and not intending to be bound by the following, each numerical parameter should be interpreted as being not only the exact number with which it is expressed, but also any approximate number descending from the exact number, with, however, the exception of any number for which a discrepancy in the order of magnitude is indicated. In other words, a range going from about 1 to about 10 should be understood as not only including back and forth the exact numbers 1 and 10, but also any approximate number descending from 1 and 10, with, however, the exception of any number for which a discrepancy in the order of magnitude is indicated.

[0021] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0022] When a range of values is disclosed herein, the range is to be construed as having endpoints that are inclusive of the minimum and maximum values, and any value or interger within the described range. Further, when a range of values is provided, it is understood that the range is inclusive of the minimum and maximum values, and any value or integer within the described range. Also, it is specifically intended that the described ranges are inclusive of all the sub-ranges falling within the described ranges. In other words, unless specifically stated otherwise, it is intended that an all-inclusive range is intended in this document. For example, a range from 1 to 10 should be interpreted to include any and all sub-ranges falling within the original specified ranges. For example, the sub-ranges 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc., are all included within the range 1 to 10.

[0023] With the increase of silicon content, the resistivity of silicon steel sheet increases, the eddy current loss decreases, and thus excellent magnetic properties are exhibited at higher frequencies. When the silicon content in the silicon steel sheet reaches 6.5 wt.%, the magnetostriction coefficient tends to zero, so that the 6.5 wt.% Si high silicon steel sheet is an ideal core material for making low noise and low iron loss, and its research and development will certainly attract widespread attention. However, the traditional non-oriented silicon steel powder metallurgy process has significant deficiencies in the control of impurities, inclusions and grain boundary oxides, and with the increase of silicon content, the material density is insufficient, the grain is coarse, the inclusion content is high, the brittleness of the silicon steel sheet increases, the magnetic loss is high, and the stability of the finished product is insufficient, so it is difficult to obtain stable products, which has restricted the development of 6.5 wt.% Si high silicon steel. Based on this, the application provides a preparation method of non-oriented high silicon steel and non-oriented high silicon steel, which can be used as a core material, can effectively refine the grain as much as possible in the initial state, and reduce the impurity and residual oxygen content, so that the non-oriented high silicon steel prepared by the method can reduce the risk of cracks during rolling, realize the synergistic improvement of the plasticity and magnetic properties of the non-oriented high silicon steel material, and thus obtain a high silicon steel material which is corrosion-resistant, easy to process and has excellent magnetic properties.

[0024] Please refer to Figure 1 , Figure 1is a flowchart of a preparation method of a non-oriented high silicon steel according to an exemplary embodiment. The present specification provides method operation steps as described in the embodiments or flowcharts, but can include more or fewer operation steps based on conventional or non-creative labor. The order of steps listed in the embodiments is only one of the many step execution orders, and does not represent the only execution order. In actual system or server product execution, the method order shown in the embodiments or drawings can be executed in sequence or in parallel (for example, in a parallel processor or multi-thread processing environment). Specifically, as shown in Figure 1 The above method can include: S101: Melting the mixed raw materials to obtain an initial alloy melt.

[0025] In one specific embodiment, the mixed raw materials can include multiple metal elements such as iron, silicon, carbon, manganese, phosphorus, and sulfur, and the multiple metal elements are mixed in a certain proportion. Specifically, the multiple metal raw materials can be fully mixed according to a certain component ratio, heated to 1450°C-1500°C by a vacuum induction furnace for melting to obtain an initial alloy melt.

[0026] S103: At a preset distance below the liquid surface of the initial alloy melt, ultrasonic treatment is performed on the initial alloy melt to obtain an ultrasonic treated alloy melt.

[0027] In one specific embodiment, the ratio between the preset distance and the depth of the initial alloy melt is greater than or equal to 1 / 10, for example, it can be 1 / 10, 1 / 9, 1 / 8, etc. Specifically, the preset distance can be greater than or equal to 20mm, for example, it can be 20mm, 22mm, 24mm, 25mm, 26mm, 28mm, 30mm. The duration of the ultrasonic treatment is any value between 30s and 40s, such as 30s, 32s, 34s, 35s, 36s, 38s, 40s, etc. The frequency of the ultrasonic treatment is any value between 15kHz and 20kHz, such as 15kHz, 16kHz, 17kHz, 18kHz, 19kHz, 20kHz, etc. The power of the ultrasonic treatment can be determined based on the depth of the alloy melt. Specifically, when the depth of the alloy melt is less than or equal to a first depth threshold, the power can be set to any value between 800W and 1000W, such as 800W, 850W, 900W, 950W, 1000W, etc. When the depth of the alloy melt is greater than the first depth threshold and less than or equal to a second depth threshold, the power can be set to any value between 1600W and 2000W, such as 1600W, 1650W, 1700W, 1750W, 1800W, 1900W, 2000W, etc. Specifically, the first depth threshold and the second depth threshold can be set according to actual application requirements. For example, the first depth threshold can be set to 0.6m and the second depth threshold can be set to 1m.

[0028] In an optional embodiment, the ultrasonic treatment of the initial alloy melt at a predetermined distance below the surface of the initial alloy melt to obtain the ultrasonically treated alloy melt may include: When the initial alloy melt is stable, at a preset temperature, an ultrasonic probe is inserted into the initial alloy melt to a preset distance below the surface of the initial alloy melt to perform ultrasonic treatment on the initial alloy melt, thereby obtaining an ultrasonically treated alloy melt.

[0029] In one specific embodiment, the preset temperature can be set according to actual application requirements, for example, it can be set to 1400℃. Specifically, the ultrasonic probe can be made of stainless steel with a titanium nitride coating, silicon nitride, or niobium alloy.

[0030] S105: At a predetermined distance from the bottom of the ultrasonically treated alloy melt, ultrasonic treatment is performed on the ultrasonically treated alloy melt to obtain the target alloy melt.

[0031] Optionally, the above-mentioned ultrasonic treatment of the ultrasonically treated alloy melt at a preset distance from the bottom of the ultrasonically treated alloy melt to obtain the target alloy melt may include, after the ultrasonically treated alloy melt has stabilized, inserting the ultrasonic probe back into the initial alloy melt to a preset distance from the bottom of the alloy melt, and ultrasonically treating the ultrasonically treated alloy melt again to obtain the target alloy melt.

[0032] In one specific embodiment, the ultrasonic probe may include a first ultrasonic probe and a second ultrasonic probe. During the ultrasonic processing, the first ultrasonic probe and the second ultrasonic probe extend from both ends of the alloy melt to a predetermined distance below the surface of the alloy melt, and extend to a predetermined distance from the bottom of the alloy melt, respectively.

[0033] In practical applications, after smelting, ultrasonic treatment is performed at 1400℃. Once the alloy melt stabilizes, two variable-amplitude ultrasonic probes are inserted into the alloy melt from both ends to perform ultrasonic treatment. The probes are moved from one end to the other, with the probes positioned approximately 20mm to 30mm below the surface of the alloy melt. Ultrasonic treatment is performed for 30 to 40 seconds at the appropriate ultrasonic power and frequency, after which the probes are removed. After the alloy melt stabilizes following the first ultrasonic treatment, the probes are inserted into the alloy melt again, with the probes positioned approximately 20mm to 30mm from the bottom of the alloy melt. This ultrasonic treatment process is repeated to further refine the grains before casting into ingots.

[0034] In the above embodiments, the non-oriented high-silicon steel undergoes two ultrasonic treatments during smelting to effectively refine the grains in the initial state, reduce impurities and residual oxygen content, achieve fine grains, prevent element enrichment, reduce precipitate formation, and prevent a significant increase in harmful textures such as γ-texture. This effectively enhances the plasticity of the high-silicon steel while simultaneously improving its strength and magnetic properties. Furthermore, by optimizing processing parameters and synergistically controlling its microstructure and properties, this invention addresses the problems of cracking, unfavorable texture formation, increased brittleness, and reduced iron loss that are common during the cold rolling of traditional high-silicon steel. It reduces the risk of cracking during rolling, improves the strength and plasticity of the non-oriented high-silicon steel, thereby significantly enhancing its magnetic properties, optimizing and improving the performance of high-silicon steel, and ensuring the industrial feasibility of the process and the consistency of the finished products.

[0035] S107: The target alloy molten metal is cast and then subjected to forging, hot rolling, normalizing, primary annealing, pickling, cold rolling and secondary annealing in sequence to obtain non-oriented high silicon steel.

[0036] Optionally, the primary annealing treatment can be carried out in a hydrogen atmosphere, and the secondary annealing treatment can be carried out in an inert gas atmosphere. The temperature of the primary annealing treatment is higher than that of the secondary annealing treatment. For example, the temperature of the primary annealing treatment can be 1200℃, and the temperature of the secondary annealing treatment can be 1050℃. Specifically, the inert gas can be nitrogen or argon.

[0037] Optionally, the above-mentioned casting of the target alloy molten metal, followed by forging, hot rolling, normalizing, primary annealing, pickling, cold rolling, and secondary annealing to obtain non-oriented high-silicon steel material may include: The target alloy molten material is cast and forged, and then hot-rolled to the first target thickness to obtain hot-rolled silicon steel material; Hot-rolled silicon steel material is subjected to normalizing treatment, one-time annealing and pickling treatment in sequence, and then cold-rolled to the second target thickness to obtain cold-rolled silicon steel material; Cold-rolled silicon steel is subjected to secondary annealing to obtain non-oriented high-silicon steel.

[0038] Specifically, the first target thickness can be 2.5 mm, and the second target thickness can be 0.2 mm. In practical applications, the ultrasonically treated alloy melt is cast into an ingot, then forged using air free forging, and repeatedly drawn at 1200℃ to form a square billet with a thickness of 20 mm. Afterwards, hot rolling is performed, with the billet heated to 1100℃, held in a 1000℃ furnace for 2 hours, and then symmetrically rolled in multiple passes to the target thickness of 2.5 mm. Normalization is then performed using a medium-temperature normalization process (850℃, 2.5 h) to promote texture and microstructure control, resulting in a fully recrystallized microstructure. Following this, homogenization annealing is performed, with the plate annealed at 1200℃ for 4 hours to improve compositional uniformity. Finally, pickling is performed using a dilute hydrochloric acid solution (0.5 mol / L). Afterwards, it undergoes room temperature cold rolling to a plate thickness of 0.2 mm. Multiple decreasing deformation passes are used, with a total deformation rate of over 80%. Finally, it undergoes annealing at 1050℃ under an argon protective atmosphere for 4 hours to eliminate residual stress and complete the recrystallization process.

[0039] In one specific embodiment, the non-oriented high silicon steel prepared by the above method of the present invention can reduce the fracture probability by 75% to 80% during cold rolling, and its grain size can be 15 micrometers to 30 micrometers, with a tensile strength greater than or equal to 450 MPa and an elongation greater than or equal to 15%.

[0040] This application also provides a non-oriented high-silicon steel, which is prepared by the above-described preparation method.

[0041] This application also provides an application of the non-oriented high-silicon steel as described above, which is used as a core material. The non-oriented high-silicon steel is prepared by the above-described preparation method, wherein the core material can be the core material of equipment such as electric motors, generators, and transformers.

[0042] The present invention will be further described in detail below through examples and comparative examples.

[0043] Example 1 Step 1: Melting: Mix the raw materials thoroughly according to a certain composition ratio, and then heat them to 1500℃ in a vacuum induction furnace for refining.

[0044] Step 2: First ultrasonic treatment: After melting, ultrasonic treatment is performed at 1400℃ until the alloy melt stabilizes. Two amplitude-modulated probes, made of stainless steel coated with a TiN film or isostatically pressed silicon nitride ceramic, niobium alloy, etc., are inserted into the alloy melt from both ends for ultrasonic treatment. The probes are moved from one end to the other, with the probe depth to the alloy melt surface ratio being 1:10. The power is 1000W (solution volume is 0.13m³), the vibration frequency is 20kHz, and the time is 40s. Afterwards, the probes are extended.

[0045] Step 3: Secondary ultrasonic treatment: After the alloy liquid stabilizes, insert the probe into the alloy liquid surface again. The ratio of probe depth to alloy liquid surface is 9:10, the power is 1000W, the vibration frequency is 20kHz, and the time is 40s.

[0046] Step 4: Casting: The ultrasonically treated alloy melt is cast into an ingot.

[0047] Step 5: Forging: The billet is forged into a 20 mm thick square billet by air free forging and multiple drawing under heating conditions of 1200℃.

[0048] Step 6: Heat the forging billet to 1100℃, hold it in a heating furnace at 1000℃ for 2 hours, and then roll it symmetrically in multiple passes to the target thickness of 2.5mm.

[0049] Step 7: Normalization treatment: Use medium-temperature normalization (850℃, 2.5h) to promote texture and structure regulation so that it forms a fully recrystallized structure.

[0050] Step 8: First annealing: Anneal the board at 1200℃ for 4 hours to improve the uniformity of composition.

[0051] Step 9: Pickling: Use dilute hydrochloric acid solution (0.5 mol / L) as the pickling solution.

[0052] Step 10: Room temperature cold rolling: Cold rolling to a plate thickness of 0.2mm, using multiple decreasing deformation passes, with a total deformation rate of over 80%.

[0053] Step 11: Secondary annealing: Anneal at 1050℃ under an argon protective atmosphere for 4 hours to eliminate residual stress and complete the recrystallization process.

[0054] The non-oriented high-silicon steel material prepared by the above method was found to have a fracture probability reduced by 80%, an average grain size of 15 micrometers, a tensile strength of 475 MPa, and an elongation of 15%.

[0055] Example 2 Step 1: Melting: Mix the raw materials thoroughly according to a certain composition ratio, and then heat them to 1450℃ in a vacuum induction furnace for refining.

[0056] Step 2: First ultrasonic treatment: After melting, ultrasonic treatment is performed at 1400℃. Once the alloy melt is stable, two amplitude-modulated probes are inserted into the alloy melt from both ends for ultrasonic treatment. The probes are moved from one end to the other, with the probe depth to the alloy melt surface ratio being 1:10. The power is 800W (solution volume is 0.13m³), the vibration frequency is 15kHz, and the time is 30s, after which the probes are extended.

[0057] Step 3: Secondary ultrasonic treatment: After the alloy liquid stabilizes, insert the probe into the alloy liquid surface again. The ratio of probe depth to alloy liquid surface is 9:10, the power is 800W, the vibration frequency is 15kHz, and the time is 30s.

[0058] Steps 4 to 11 are the same as in Example 1, and will not be repeated here.

[0059] The non-oriented high-silicon steel material prepared by the above method showed a 76% decrease in fracture probability, an average grain size of 17 micrometers, a tensile strength of 460 MPa, and an elongation of 14%.

[0060] Comparative Example 1 Step 1: Melting: Mix the raw materials thoroughly according to a certain composition ratio, and then heat them to 1500℃ in a vacuum induction furnace for refining.

[0061] Step 2: After melting, ultrasonic treatment is performed at 1400℃. Once the alloy melt stabilizes, two amplitude-modulated probes are inserted into the alloy melt from both ends for ultrasonic treatment. The probes are moved from one end to the other, with the probe depth to the alloy melt surface ratio being 1:10. The power is 1000W (solution volume is 0.13m³), the vibration frequency is 10kHz, and the time is 40s. Afterward, the probes are extended.

[0062] Step 3: Secondary ultrasonic treatment: After the alloy liquid stabilizes, insert the probe into the alloy liquid surface again. The ratio of probe depth to alloy liquid surface is 9:10, the power is 1000W, the vibration frequency is 10kHz, and the time is 40s.

[0063] Steps 4 to 11 are the same as in Example 1, and will not be repeated here.

[0064] The non-oriented high-silicon steel material prepared by the above method was found to have a 50% decrease in fracture probability, an average grain size of 20 micrometers, a tensile strength of 400 MPa, and an elongation of 13%.

[0065] Comparative Example 2 Step 1: Melting: Mix the raw materials thoroughly according to a certain composition ratio, and then heat them to 1500℃ in a vacuum induction furnace for refining.

[0066] Step 2: First ultrasonic treatment: After melting, ultrasonic treatment is performed at 1400℃. Once the alloy melt stabilizes, two amplitude-modulated probes are inserted into the alloy melt from both ends for ultrasonic treatment. The probes are moved from one end to the other, with the probe depth to the alloy melt surface ratio being 1:10. The power is 1000W (solution volume is 0.13m³), the vibration frequency is 30kHz, and the time is 40s. Afterward, the probes are extended.

[0067] Step 3: Secondary ultrasonic treatment: After the alloy liquid stabilizes, insert the probe into the alloy liquid surface again. The ratio of probe depth to alloy liquid surface is 9:10, the power is 1000W, the vibration frequency is 30kHz, and the time is 40s.

[0068] Steps 4 to 11 are the same as in Example 1, and will not be repeated here.

[0069] The non-oriented high-silicon steel material prepared by the above method showed a 70% reduction in fracture probability, an average grain size of 17 micrometers, a tensile strength of 450 MPa, and an elongation of 14%.

[0070] Comparative Example 3 Step 1: Melting: Mix the raw materials thoroughly according to a certain composition ratio, and then heat them to 1500℃ in a vacuum induction furnace for refining.

[0071] Step 2: First ultrasonic treatment: After melting, ultrasonic treatment is performed at 1400℃. Once the alloy melt is stable, two amplitude-modulated probes are inserted into the alloy melt from both ends for ultrasonic treatment. The probes are moved from one end to the other, with the probe depth to the alloy melt surface ratio being 1:10. The power is 1000W (solution volume is 0.13m³), the vibration frequency is 20kHz, and the time is 10s, after which the probes are extended.

[0072] Step 3: Secondary ultrasonic treatment: After the alloy liquid stabilizes, insert the probe into the alloy liquid surface again. The ratio of probe depth to alloy liquid surface is 9:10, the power is 1000W, the vibration frequency is 20kHz, and the time is 10s.

[0073] Steps 4 to 11 are the same as in Example 1, and will not be repeated here.

[0074] The non-oriented high-silicon steel material prepared by the above method showed a 40% decrease in fracture probability, an average grain size of 25 micrometers, a tensile strength of 350 MPa, and an elongation of 13%.

[0075] Comparative Example 4 Step 1: Melting: Mix the raw materials thoroughly according to a certain composition ratio, and then heat them to 1500℃ in a vacuum induction furnace for refining.

[0076] Step 2: First ultrasonic treatment: After melting, ultrasonic treatment is performed at 1400℃. Once the alloy melt is stable, two amplitude-modulated probes are inserted into the alloy melt from both ends for ultrasonic treatment. The probes are moved from one end to the other, with the probe depth to the alloy melt surface ratio being 1:10. The power is 500W (solution volume is 0.13m³), the vibration frequency is 20kHz, and the time is 60s. Afterward, the probes are extended.

[0077] Step 3: Secondary ultrasonic treatment: After the alloy liquid stabilizes, insert the probe into the alloy liquid surface again. The ratio of probe depth to alloy liquid surface is 9:10, the power is 500W, the vibration frequency is 20kHz, and the time is 60s.

[0078] Steps 4 to 11 are the same as in Example 1, and will not be repeated here.

[0079] The non-oriented high-silicon steel material prepared by the above method was found to have a 40% decrease in fracture probability, an average grain size of 30 micrometers, a tensile strength of 355 MPa, and an elongation of 10%.

[0080] Comparative Example 5 Step 1: Melting: Mix the raw materials thoroughly according to a certain composition ratio (reduce the silicon content to 2%) and refine them by heating to 1500℃ in a vacuum induction furnace.

[0081] Step 2: First ultrasonic treatment: After melting, ultrasonic treatment is performed at 1400℃. Once the alloy melt is stable, two amplitude-modulated probes are inserted into the alloy melt from both ends for ultrasonic treatment. The probes are moved from one end to the other, with the probe depth to the alloy melt surface ratio being 1:10. The power is 500W (solution volume is 0.13m³), the vibration frequency is 20kHz, and the time is 60s. Afterward, the probes are extended.

[0082] Step 3: Secondary ultrasonic treatment: After the alloy liquid stabilizes, insert the probe into the alloy liquid surface again. The ratio of probe depth to alloy liquid surface is 9:10, the power is 500W, the vibration frequency is 20kHz, and the time is 60s.

[0083] Steps 4 to 11 are the same as in Example 1, and will not be repeated here.

[0084] The non-oriented high-silicon steel material prepared by the above method was found to have a 30% decrease in fracture probability, an average grain size of 30 micrometers, a tensile strength of 300 MPa, and an elongation of 10%.

[0085] In summary, the non-oriented high-silicon steel material prepared in this application effectively refines the grains, reduces impurities and residual oxygen content, reduces the risk of cracking during rolling, and has high strength and plasticity, thereby improving magnetic properties, and is corrosion-resistant and easy to process.

[0086] 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 non-oriented high-silicon steel, characterized in that, include: The mixed raw materials are smelted to obtain an initial alloy melt; the mixed raw materials include iron, silicon, carbon, manganese, phosphorus and sulfur; The initial alloy melt is ultrasonically treated at a predetermined distance below the surface of the initial alloy melt to obtain an ultrasonically treated alloy melt. The ratio between the predetermined distance and the depth of the initial alloy melt is greater than or equal to 1 / 10. The duration of the ultrasonic treatment is 30s to 40s, the frequency of the ultrasonic treatment is 15kHz to 20kHz, and the power of the ultrasonic treatment is determined based on the depth of the alloy melt. When the depth of the initial alloy melt is less than or equal to a first depth threshold, the power is 800W to 1000W. When the depth of the initial alloy melt is greater than the first depth threshold and less than or equal to a second depth threshold, the power is 1600W to 2000W. At a predetermined distance from the bottom of the ultrasonically treated alloy melt, the ultrasonically treated alloy melt is subjected to ultrasonic treatment to obtain the target alloy melt. The target alloy molten metal is cast and then subjected to forging, hot rolling, normalizing, primary annealing, pickling, cold rolling, and secondary annealing in sequence to obtain non-oriented high-silicon steel. The non-oriented high-silicon steel comprises the following components by mass percentage: silicon 5.0%~6.5%, carbon less than or equal to 0.005%, manganese 0.10%~0.25%, phosphorus less than or equal to 0.03%, sulfur less than or equal to 0.005%, with the remainder being iron and unavoidable impurities.

2. The method according to claim 1, characterized in that, The step of ultrasonically treating the initial alloy melt at a predetermined distance below the surface of the initial alloy melt to obtain an ultrasonically treated alloy melt includes: When the initial alloy melt is stable, at a preset temperature, an ultrasonic probe is inserted into the initial alloy melt to a preset distance below the surface of the initial alloy melt to perform ultrasonic treatment on the initial alloy melt, thereby obtaining the ultrasonically treated alloy melt.

3. The method according to claim 2, characterized in that, The ultrasonic probe includes a first ultrasonic probe and a second ultrasonic probe. During the ultrasonic treatment, the first ultrasonic probe and the second ultrasonic probe extend from both ends of the alloy melt to a predetermined distance below the surface of the initial alloy melt.

4. The method according to claim 2 or 3, characterized in that, The ultrasonic probe is made of stainless steel with a titanium nitride coating, or silicon nitride, or niobium alloy.

5. The method according to claim 1, characterized in that, The grain size of the non-oriented high-silicon steel is 15 micrometers to 30 micrometers.

6. The method according to claim 1, characterized in that, The preset distance is greater than or equal to 20mm.

7. The method according to claim 1, characterized in that, The first annealing process is carried out in a hydrogen atmosphere, and the second annealing process is carried out in an inert gas atmosphere. The temperature of the first annealing process is higher than that of the second annealing process. The inert gas is nitrogen or argon.

8. The method according to claim 1, characterized in that, The process of casting the target alloy molten metal and sequentially performing forging, hot rolling, normalizing, primary annealing, pickling, cold rolling, and secondary annealing to obtain non-oriented high-silicon steel material includes: The target alloy molten material is cast and forged, and then hot-rolled to a first target thickness to obtain hot-rolled silicon steel material; The hot-rolled silicon steel material is subjected to normalizing treatment, primary annealing and pickling treatment in sequence, and then cold-rolled to the second target thickness to obtain cold-rolled silicon steel material; The cold-rolled silicon steel material is subjected to a secondary annealing treatment to obtain the non-oriented high-silicon steel.

9. A non-oriented high-silicon steel, characterized in that, It is prepared by the method for preparing non-oriented high silicon steel as described in any one of claims 1 to 8.

10. An application of a non-oriented high-silicon steel, characterized in that, The non-oriented high-silicon steel is used as a core material, and the non-oriented high-silicon steel is prepared by the preparation method of non-oriented high-silicon steel as described in any one of claims 1 to 8.

Images