High-plasticity high-silicon silicon steel and preparation method and application thereof

Abstract

The invention relates to high-plasticity high-silicon silicon steel and a preparation method and application thereof, and belongs to the technical field of soft magnetic material manufacturing. The high-plasticity high-silicon silicon steel comprises the following chemical components: 3.5-6.6% of Si, 0.5-2.0% of Al, 0.02-0.1% of B, 0.03-0.06% of Zr, 0.1-0.5% of Mn, less than or equal to 0.005% of C, less than or equal to 0.003% of S, less than or equal to 0.004% of P, less than or equal to 0.003% of N, less than or equal to 0.003% of O and the balance of Fe and inevitable impurities. Through mutual cooperation of the elements, especially the addition of the B and Zr elements, grains are refined, the content of ordered phases is reduced, the plasticity of the high-silicon silicon steel is improved, and the obtained high-silicon silicon steel does not have brittle fracture; and meanwhile, the high-silicon silicon steel with high magnetic induction intensity, low iron loss and excellent thickness tolerance and surface quality is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soft magnetic material manufacturing, and particularly relates to a high-plasticity high-silicon silicon steel and a preparation method and application thereof. BACKGROUND

[0002] The high-silicon silicon steel is a key soft magnetic material for manufacturing high-efficiency motor and transformer cores. With the development of electrical equipment towards high efficiency and miniaturization, higher requirements are put forward for the magnetic induction intensity and iron loss of the silicon steel material.

[0003] At present, the preparation of the high-silicon silicon steel mainly adopts a traditional continuous casting and rolling process. However, when the silicon content is more than 3.5%, the plasticity of the material is significantly reduced, and the traditional continuous casting and rolling process is prone to brittle fracture, which leads to a substantial increase in production difficulty. Moreover, a large hot rolling reduction and a large cold rolling reduction can result in strong {111} texture in the final high-silicon silicon steel structure, which is not conducive to the improvement of the magnetic induction intensity of the silicon steel. SUMMARY

[0004] In view of the above analysis, the present application aims to provide a high-plasticity high-silicon silicon steel and a preparation method and application thereof, so as to solve the problem of brittle fracture caused by the existing preparation method and improve the performance of the high-silicon silicon steel.

[0005] In one aspect, the present application provides a high-plasticity high-silicon silicon steel, and the chemical composition thereof includes, in terms of mass percentage, Si: 3.5-6.6%, Al: 0.5-2.0%, B: 0.02-0.1%, Zr: 0.03-0.06%, Mn: 0.1-0.5%, C≤0.005%, S≤0.003%, P≤0.004%, N≤0.003%, O≤0.003%, and the balance of Fe and inevitable impurities.

[0006] Further, the chemical composition includes Si: 3.5-5.5%, Al: 0.5-1.0%, B: 0.02-0.07%, Zr: 0.045-0.06%, Mn: 0.1-0.4%, C≤0.005%, S≤0.003%, P≤0.004%, N≤0.003%, O≤0.003%, and the balance of Fe and inevitable impurities.

[0007] Further, the Si+Al content is≤6.8%.

[0008] Further, the magnetic induction intensity B 50 ≥1.65T, the iron loss P 2 / 5000 ≤7.5W / kg, and the elongation≥5%.

[0009] In another aspect, the present application provides a preparation method of the high-plasticity high-silicon silicon steel, including the following steps:

[0010] S1: vacuum induction smelting the raw materials to obtain molten steel;

[0011] S2: transferring the molten steel into a holding furnace to perform remelting and holding;

[0012] S3: planar flow casting the molten steel after holding, injecting through a nozzle to a cooling roller to form a cast strip;

[0013] S4: performing flat rolling on the obtained cast strip to obtain a rolled material;

[0014] S5: finally performing recrystallization annealing on the obtained rolled material to obtain high-silicon silicon steel.

[0015] Further, in step S1, the smelting temperature is 1600-1650℃; in step S2, the temperature of remelting and holding is 1550-1580℃.

[0016] Further, in step S3, the pressure of the injection is 0.02-0.06MPa, the linear speed of the cooling roller is 15-30m / s, and the distance between the nozzle and the cooling roller is 0.05-0.4mm.

[0017] Further, in step S4, the total reduction of flat rolling is 2%-30%.

[0018] Further, in step S5, the recrystallization annealing is performed under hydrogen protection, the temperature of recrystallization annealing is 1000-1150℃, and the holding time of recrystallization annealing is 5-30 minutes.

[0019] Further, the high-plasticity high-silicon silicon steel is used to prepare an ultrathin strip, the thickness of the obtained ultrathin strip is 0.03-0.05mm, the thickness tolerance is ≤±0.01mm, and the surface roughness Ra is ≤0.5μm.

[0020] Compared with the prior art, the present application can achieve at least one of the following beneficial effects:

[0021] 1. In the present application, the plasticity of high-silicon silicon steel is improved by the mutual cooperation between elements, especially by adding B and Zr elements to refine the grain and reduce the ordered phase content; the obtained high-silicon silicon steel does not occur brittle fracture; meanwhile, the high-silicon silicon steel with high magnetic induction intensity, low iron loss, excellent thickness tolerance and surface quality is obtained; the magnetic induction intensity B 50 of the obtained high-silicon silicon steel is ≥1.65T, the iron loss P 2 / 5000 is ≤7.5W / kg, and the elongation is above 5%.

[0022] 2. The preparation method of the high-silicon silicon steel comprises vacuum induction melting, remelting and holding, plane flow casting, flat rolling and recrystallization annealing, and the process parameters of each step are controlled, so that the problem of brittle fracture caused by the existing preparation method (continuous casting and rolling) is solved.

[0023] 3. The high-silicon silicon steel provided by the application is used for preparing an ultra-thin strip, the thickness of the strip is 0.03-0.05 mm, the thickness tolerance is ≤±0.01 mm, and the surface roughness Ra is ≤0.5 μm.

[0024] The above technical solutions can be combined with each other to achieve more preferred combination solutions. Other features and advantages of the application will be described in the subsequent specification, and some advantages will become apparent from the specification, or will be understood by implementing the application. The purposes and other advantages of the application can be achieved and obtained from the contents specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of the application and are incorporated herein and constitute a part of the application. The same reference numbers in the drawings indicate the same elements throughout the drawings.

[0026] Figure 1 The silicon steel ultra-thin strip obtained in Example 1;

[0027] Figure 2 The EBSD orientation imaging map (ipf-z) of the high-silicon silicon steel thin strip;

[0028] Figure 3 The partial enlarged view of Figure 2

[0029] Figure 4 The EBSD inverse pole figure map ( / / z) of the high-silicon silicon steel thin strip. DETAILED DESCRIPTION

[0030] The preferred embodiments of the application are specifically described below with reference to the accompanying drawings, which form a part of the application and are used to explain the principles of the application together with the embodiments of the application, and are not used to limit the scope of the application.

[0031] The high-silicon silicon steel is a key soft magnetic material for manufacturing high-efficiency motor and transformer cores. With the development of electrical equipment towards high efficiency and miniaturization, higher requirements are put forward for the magnetic induction intensity and iron loss of the silicon steel material.

[0032] ​Currently, high-silicon steel is mainly produced using traditional continuous casting and rolling processes. However, when the silicon content exceeds 3.5%, the material's plasticity decreases significantly, making it prone to brittle fracture using traditional continuous casting and rolling processes, which greatly increases production difficulty. Furthermore, the large hot-rolling and cold-rolling reductions result in a strong {111} texture in the final high-silicon steel microstructure, which is detrimental to improving the magnetic induction intensity of the silicon steel.

[0033] Therefore, the present invention provides a high-plasticity, high-silicon steel, the chemical composition of which, by mass percentage, includes: Si: 3.5–6.6%, Al: 0.5–2.0%, B: 0.02–0.1%, Zr: 0.03–0.06%, Mn: 0.1–0.5%, C≤0.005%, S≤0.003%, P≤0.004%, N≤0.003%, O≤0.003%, with the balance being Fe and unavoidable impurities.

[0034] Compared with existing technologies, this invention, through the synergistic effect of elements, especially the addition of B and Zr elements, refines the grain size, reduces the content of ordered phases, and improves the plasticity of high-silicon steel, resulting in high-silicon steel that does not undergo brittle fracture; simultaneously, it yields high-silicon steel with high magnetic induction intensity, low iron loss, excellent thickness tolerance, and surface quality; the resulting high-silicon steel has a high magnetic induction intensity of B... 50 ≥1.65T, iron loss P 2 / 5000 ≤7.5W / kg, with an elongation of ≥5%.

[0035] The functions of each element are as follows:

[0036] Silicon (Si) can effectively increase the resistivity of silicon steel, reduce hysteresis loss, and thus increase the magnetic flux density of silicon steel. However, excessive silicon content can lead to a decrease in the processing quality of silicon steel and also reduce its magnetic flux density. Therefore, its content is controlled within the range of 3.5% to 6.6%.

[0037] Al can increase the resistivity of silicon steel and promote grain growth, thus reducing iron loss. Furthermore, the addition of Al helps increase the proportion of columnar crystals in the cast silicon steel structure. However, both Si and Al can lead to decreased material plasticity, and excessive content can cause rolling cracks during the leveling and rolling process. Therefore, the content of Si and Al should be controlled to ≤6.8%.

[0038] Boron (B) exists as a precipitated phase in silicon steel, significantly reducing the anisotropy of magnetic induction and iron loss. Furthermore, the addition of B lowers the solid-liquid phase line, improving formability and reducing manufacturing costs. However, excessive B can also impair magnetic properties; therefore, its content is controlled within the range of 0.02–0.1%.

[0039] Zr can refine grains, reduce the content of ordered phases, and improve the plasticity of silicon steel or ultra-thin strips. During subsequent recrystallization annealing, it promotes the growth of Goss grains, thereby increasing magnetic induction and reducing iron loss. The combined addition of boron and zr can promote segregation at grain boundaries, suppress undesirable precipitates, and increase the recrystallization temperature, which is beneficial for obtaining a uniform recrystallized structure. Therefore, the content of zr should be controlled at 0.03–0.06%.

[0040] Mn plays a solid solution strengthening role in silicon steel, which can improve the resistivity of silicon steel and reduce iron loss. However, excessive Mn can coarsen MnS, hinder grain growth, increase the strength of harmful {111} texture components, and impair the magnetic properties of silicon steel; therefore, the Mn content is 0.1% to 0.5%.

[0041] Sulfur (S) in silicon steel mainly exists as sulfide inclusions, which reduces the formability of silicon steel and its content should be minimized. Phosphorus (P) is generally considered a harmful impurity element in silicon steel. It easily segregates at grain boundaries, significantly reducing grain boundary strength and causing cold brittleness, making high-silicon steel more prone to cracking during rolling. It also increases iron loss and its content should be minimized.

[0042] In silicon steel, carbon exists as dissolved carbon or fine cementite. It precipitates during long-term use or annealing, causing the magnetic properties to deteriorate continuously. It must be reduced to an extremely low level to ensure magnetic stability.

[0043] Oxide (O) readily forms oxide inclusions (such as SiO2 and Al2O3), disrupting matrix continuity, increasing hysteresis loss, worsening iron loss, and reducing material plasticity and surface quality. Therefore, its content must be strictly controlled.

[0044] Nitrogen (N) forms fine, dispersed nitrides (AlN, BN) with Al, B, and other elements, pinning grain boundaries and causing material embrittlement, difficulty in processing, and hindering grain growth, thus deteriorating magnetism. Therefore, its content must be strictly controlled.

[0045] Preferably, its chemical composition includes: Si: 3.5-5.5%, Al: 0.5-1.0%, B: 0.02-0.07%, Zr: 0.045-0.06%, Mn: 0.1-0.4%, C≤0.005%, S≤0.003%, P≤0.004%, N≤0.003%, O≤0.003%, with the balance being Fe and unavoidable impurities.

[0046] Specifically, the Si+Al content in the chemical composition is ≤6.8%.

[0047] This invention provides a method for preparing high-plasticity, high-silicon steel, comprising the following steps:

[0048] S1: Vacuum induction melting of the raw materials yields molten steel;

[0049] S2: Transfer the molten steel into a holding furnace for remelting and heat preservation;

[0050] S3: The heat-insulated molten steel is then poured into a flat flow casting process, and sprayed onto the cooling rollers through nozzles to form a casting strip;

[0051] S4: The obtained cast strip is leveled and rolled to obtain rolled material;

[0052] S5: Finally, the obtained rolled material is recrystallized and annealed to obtain high silicon steel.

[0053] It should be noted that the preparation method of high silicon steel of the present invention includes vacuum induction melting, remelting and holding, planar flow casting, leveling rolling and recrystallization annealing, and controls the process parameters of each step, which solves the problem of brittle fracture caused by the existing preparation method (continuous casting and rolling).

[0054] Specifically, in step S1, the melting temperature is 1600-1650℃; in step S2, the remelting holding temperature is 1550-1580℃.

[0055] It should be noted that the vacuum induction melting step involves adding pure iron, ferrosilicon, aluminum ingots, and other raw materials to a vacuum induction melting furnace according to a specified ratio, and then evacuating the furnace to a vacuum level of 5 × 10⁻⁶. -3 Pa, during melting, high-purity argon gas is introduced to 0.05 MPa, and the temperature is raised to 1600-1650℃ to completely melt the raw materials, and then refined for 20 minutes.

[0056] This invention controls the melting temperature at 1600–1650℃ to ensure complete melting and uniform composition. The melting point of high-silicon steel is approximately 1500℃. Setting the melting temperature to 1600–1650℃ guarantees a superheat of approximately 100–150℃. Sufficient superheat ensures that all alloying elements (especially high-melting-point Zr, etc.) are completely dissolved, and the electromagnetic stirring action of the induction furnace achieves rapid homogenization of the composition, avoiding segregation. Furthermore, the high temperature and high vacuum conditions facilitate the escape of gaseous elements (such as hydrogen and nitrogen) from the molten steel. Excessively high temperatures can cause element burn-off and volatilization. The vacuum induction melting temperature of this invention can be 1600℃, 1610℃, 1620℃, 1630℃, 1640℃, or 1650℃.

[0057] During the remelting and holding process, molten steel is transferred to a holding furnace and held at 1550–1580℃ for 20–40 minutes. The remelting and holding temperature can be 1550℃, 1555℃, 1560℃, 1565℃, 1570℃, 1575℃, or 1580℃. Excessive temperature will cause increased solidification shrinkage of the liquid metal, resulting in coarse grains and deteriorating the mechanical and magnetic properties of the strip. It will also cause excessive thermal shock to the nozzles and rollers, reducing equipment lifespan. Conversely, excessively low temperatures will reduce the fluidity of the molten steel, increase its viscosity, and make it difficult to pass stably and continuously through the narrow nozzle slits. Premature solidification is highly likely to occur inside the nozzle or at the outlet, causing nozzle blockage, strip breakage, and making the process impossible. The resulting strip will have poor surface quality and uneven thickness.

[0058] Specifically, in step S3, the injection pressure is 20–60 kPa, the linear velocity of the cooling roller is 15–30 m / s, and the cooling water flow rate is 10–20 m³ / s. 3 / h, the distance between the nozzle and the cooling roller is 0.05 to 0.4 mm.

[0059] It should be noted that in this invention, it is necessary to control the injection pressure, the linear velocity of the cooling roller, the cooling water flow rate, and the distance between the nozzle and the cooling roller. The injection pressure directly affects the injection speed, and its function is to control the output volume and speed of the molten metal flow to form a molten pool. Excessive pressure will result in excessive injection speed, leading to strip thickness and affecting the stability of the molten pool; inappropriate pressure may also cause surface defects.

[0060] The linear speed of the cooling rollers directly controls the solidification and cooling rate of the strip and the drawing speed. Increasing the rotational speed results in thinner strips, but may cause surface voids due to gas entrapment.

[0061] The distance between the nozzle and the cooling roller affects the size, shape, and stability of the molten pool. A larger distance results in a thicker strip. Too small a distance may cause friction, while too large a distance leads to an unstable molten pool, both of which can easily cause strip breakage.

[0062] The cooling water flow rate is crucial for maintaining the low temperature of the cooling roller surface and ensuring continuous, efficient heat exchange. By controlling the thermal deformation of the cooling roller, the stability of the distance between the nozzle and the roller surface is affected, thereby influencing the transverse thickness uniformity and surface quality of the strip.

[0063] Specifically, the pressure in the molten pool is 1.05 to 1.2 atmospheres.

[0064] It should be noted that within the aforementioned pressure range, high-silicon non-oriented silicon steel ultrathin strips with "high magnetic induction, low iron loss, good plasticity, and excellent surface quality" can be stably produced. If the pressure exceeds this range, over-processing problems such as overheating, over-oxidation, over-erosion, or grain coarsening may occur. If the pressure falls below this range, under-processing problems such as incomplete melting, incomplete solidification, incomplete recrystallization, or process interruption may occur.

[0065] Specifically, in step S4, the total reduction rate of the leveling rolling is 2% to 30%.

[0066] Preferably, in step S4, the total reduction rate of the leveling rolling is 15% to 20%.

[0067] It should be noted that warm rolling at room temperature, with the total reduction controlled between 2% and 30%, effectively eliminates surface defects in the cast strip, improves surface quality and thickness uniformity, avoids the cold-rolling brittleness problem of high-silicon steel, and creates favorable conditions for obtaining texture during subsequent recrystallization through appropriate deformation. The total reduction rate of the leveling rolling in this invention can be 2%, 4%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 21%, 23%, 25%, 28%, or 30%.

[0068] Specifically, in step S5, recrystallization annealing is carried out under hydrogen protection. The recrystallization annealing temperature is 1000-1150℃, and the holding time for recrystallization annealing is 5-30 minutes.

[0069] It should be noted that complete recrystallization occurs during the annealing process, forming a uniform equiaxed crystal structure, while simultaneously eliminating internal stress and optimizing magnetic properties. Cooling methods include air cooling or controlled cooling. The recrystallization annealing temperature can be 1000℃, 1020℃, 1040℃, 1050℃, 1070℃, 1090℃, 1100℃, 1120℃, 1130℃, or 1150℃.

[0070] The present invention also provides an ultra-thin strip, wherein the thickness of the obtained high-silicon steel ultra-thin strip is 0.03 to 0.05 mm, the thickness tolerance is ≤ ±0.01 mm, and the surface roughness Ra is ≤ 0.5 μm.

[0071] It should be noted that the ultrathin strip prepared using the high-silicon steel provided by this invention did not exhibit brittle fracture, and possessed not only high plasticity but also high magnetic properties. Magnetic induction intensity B 50 ≥1.65T, iron loss P 2 / 5000 ≤7.5W / kg, elongation ≥5%.

[0072] To more clearly describe the present invention, the following embodiments and comparative examples are provided for further illustration.

[0073] Example 1

[0074] The preparation methods for silicon steel or ultra-thin strips are as follows:

[0075] S1: The raw materials are subjected to vacuum induction melting to obtain molten steel at a melting temperature of 1620℃.

[0076] S2: The molten steel is transferred to a holding furnace for remelting and holding; the remelting and holding temperature is 1560℃ and the holding time is 30min;

[0077] S3: The heat-insulated molten steel is subjected to planar flow casting and sprayed onto the cooling roller through a nozzle to form a casting strip; the spraying pressure is 0.02MPa, the linear speed of the cooling roller is 10m / s, the distance between the nozzle and the roller is 0.3mm, and the molten pool pressure is 1.1atm;

[0078] S4: The obtained cast strip is leveled and rolled to obtain rolled material; the total rolling reduction rate is 20%;

[0079] S5: Finally, the obtained rolled material is subjected to recrystallization annealing at a temperature of 1100℃ and a holding time of 15min to obtain high silicon steel or ultra-thin strip.

[0080] The chemical composition of high-silicon steel or ultra-thin strip by mass percentage is as follows: Si: 5.5%, Al: 1.0%, B: 0.07%, Zr: 0.045%, C: 0.004%, Mn: 0.4%, S: 0.002%, P: 0.003%, N: 0.002%, O: 0.002%, with the balance being Fe and unavoidable impurities.

[0081] Example 2

[0082] The preparation process of Example 2 is largely the same as that of Example 1, except that the chemical composition of the high-silicon steel or ultra-thin strip in Example 2 is as follows by mass percentage: Si: 6.0%, Al: 0.5%, B: 0.1%, Zr: 0.06%, C: 0.005%, Mn: 0.5%, S: 0.003%, P: 0.004%, N: 0.003%, O: 0.003%, with the balance being Fe and unavoidable impurities.

[0083] Example 3

[0084] The preparation process of Example 3 is largely the same as that of Example 1, except that the chemical composition of the high-silicon steel or ultra-thin strip in Example 3 is as follows by mass percentage: Si: 3.5%, Al: 0.5%, B: 0.02%, Zr: 0.03%, C: 0.003%, Mn: 0.1%, S: 0.002%, P: 0.003%, N: 0.002%, O: 0.002%, with the balance being Fe and unavoidable impurities.

[0085] Example 4

[0086] Example 4 is prepared in a similar manner to Example 1, except that in Example 4, S1: the raw materials are subjected to vacuum induction melting to obtain molten steel at a melting temperature of 1650°C.

[0087] S2: The molten steel is transferred to a holding furnace for remelting and holding; the remelting and holding temperature is 1580℃ and the holding time is 30min;

[0088] S3: The heat-insulated molten steel is subjected to planar flow casting and sprayed onto the cooling roller through a nozzle to form a casting strip; the spraying pressure is 0.06MPa, the linear speed of the cooling roller is 30m / s, the distance between the nozzle and the roller is 0.4mm, and the molten pool pressure is 1.2atm;

[0089] S4: The obtained cast strip is leveled and rolled to obtain rolled material; the total rolling reduction rate is 30%;

[0090] S5: Finally, the obtained rolled material is subjected to recrystallization annealing at a temperature of 1150°C and a holding time of 30 minutes to obtain high-silicon steel or ultra-thin strip.

[0091] Example 5

[0092] Example 5 is prepared in a similar manner to Example 1, except that in Example 5, S1: the raw materials are subjected to vacuum induction melting to obtain molten steel at a melting temperature of 1600°C.

[0093] S2: The molten steel is transferred to a holding furnace for remelting and holding; the remelting and holding temperature is 1550℃ and the holding time is 30min;

[0094] S3: The heat-insulated molten steel is subjected to planar flow casting and sprayed onto the cooling roller through a nozzle to form a casting strip; the spraying pressure is 0.02MPa, the linear speed of the cooling roller is 15m / s, the distance between the nozzle and the roller is 0.05mm, and the molten pool pressure is 1.05atm;

[0095] S4: The obtained cast strip is leveled and rolled to obtain rolled material; the total rolling reduction rate is 2%;

[0096] S5: Finally, the obtained rolled material is subjected to recrystallization annealing at a temperature of 1000℃ and a holding time of 5min to obtain high silicon steel or ultra-thin strip.

[0097] Comparative Example 1

[0098] The preparation process of Comparative Example 1 is largely the same as that of Example 1, except that Comparative Example 1 uses an existing continuous casting and rolling process, including the following steps:

[0099] Continuous casting: Molten steel that meets the composition requirements is cast into slabs about 45mm thick using a traditional continuous casting machine.

[0100] Slab heating: The slab is heated at 1250℃ for 2 hours to ensure the homogenization of alloying elements and the plasticity of subsequent hot rolling.

[0101] Hot rolling: The slab is rolled into a 2.2mm thick hot-rolled coil by performing multiple hot rolling passes with the final rolling temperature controlled at about 1000℃.

[0102] Cold rolling: After pickling the hot-rolled plate, it is cold rolled at room temperature with a target thickness of 0.05 mm.

[0103] Annealing: Anneal at 1100℃ for 15 minutes under hydrogen protection.

[0104] Comparative Example 2

[0105] The preparation process of Comparative Example 2 is largely the same as that of Example 1, except that the chemical composition of the high silicon steel or ultra-thin strip in Comparative Example 2 does not contain B and Zr elements.

[0106] Comparative Example 3

[0107] The preparation process of Comparative Example 3 is largely the same as that of Example 1, except that in Comparative Example 3, the total reduction rate of the leveling rolling in step S4 is 40%.

[0108] Comparative Example 4

[0109] The preparation process of Comparative Example 4 is largely the same as that of Example 1, except that in step S3 of Comparative Example 4, the injection pressure is 0.08 MPa, the linear velocity of the cooling roller is 50 m / s, and the distance between the nozzle and the cooling roller is 0.5 mm.

[0110] Performance testing

[0111] The above embodiments and comparative examples were subjected to performance tests, mainly including plasticity, magnetic induction intensity, and iron loss. The test results are shown in Table 1.

[0112] Table 1 Performance Test Results

[0113]

[0114]

[0115] Combined with Examples 1-5 and Comparative Examples 1-4 and referring to Table 1 and Figures 1-4 As can be seen, in this embodiment of the invention, through the synergistic effect of elements, especially the addition of B and Zr, the grain size is refined, the content of ordered phase is reduced, and the plasticity of high-silicon steel is improved. Simultaneously, the preparation method, including vacuum induction melting, remelting and holding, planar casting, leveling rolling, and recrystallization annealing, and by controlling the process parameters of each step, solves the problem of brittle fracture caused by existing preparation methods (continuous casting and rolling). The resulting high-silicon steel did not exhibit brittle fracture; simultaneously, high magnetic induction intensity, low iron loss, excellent thickness tolerance, and surface quality were obtained; the magnetic induction intensity of the obtained high-silicon steel, B...50 ≥1.65T, iron loss P 2 / 5000 ≤7.5W / kg, elongation above 5%, thickness between 0.03 and 0.05 mm, thickness tolerance ≤±0.01 mm, surface roughness Ra≤0.5 μm.

[0116] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A high plasticity high silicon silicon steel characterized in that, The chemical composition includes, in terms of mass percentage, Si: 3.5-6.6%, Al: 0.5-2.0%, B: 0.02-0.1%, Zr: 0.03-0.06%, Mn: 0.1-0.5%, C≤0.005%, S≤0.003%, P≤0.004%, N≤0.003%, O≤0.003%, and the balance of Fe and inevitable impurities.

2. The high plasticity high silicon silicon steel as claimed in claim 1, wherein, The chemical composition includes, in terms of mass percentage, Si: 3.5-6.6%, Al: 0.5-2.0%, B: 0.02-0.1%, Zr: 0.03-0.06%, Mn: 0.1-0.5%, C≤0.005%, S≤0.003%, P≤0.004%, N≤0.003%, O≤0.003%, and the balance of Fe and inevitable impurities. The chemical composition includes, in terms of mass percentage, Si: 3.5-6.6%, Al: 0.5-2.0%, B: 0.02-0.1%, Zr: 0.03-0.06%, Mn: 0.1-0.5%, C≤0.005%, S≤0.003%, P≤0.004%, N≤0.003%, O≤0.003%, and the balance of Fe and inevitable impurities.

3. The high plasticity high silicon silicon steel as claimed in claim 1 or 2, characterized in that, The Si+Al content is ≤6.8%.

4. The high plasticity high silicon silicon steel of claim 1, wherein, magnetic induction B 50 ≥ 1.65 T, iron loss P 2 / 5000 ≤ 7.5 W / kg, elongation ≥ 5%.

5. A method of producing a high-plasticity high-silicon silicon steel as claimed in any one of claims 1 to 4, characterized in that, The method comprises the following steps: S1: vacuum induction melting of raw materials to obtain molten steel; S2: transferring the molten steel into a holding furnace for remelting and holding; S3: planar flow casting of the held molten steel through a nozzle onto a cooling roller to form a cast strip; S4: flat rolling of the obtained cast strip to obtain a rolled material; S5: finally, recrystallization annealing of the obtained rolled material to obtain a high-silicon silicon steel.

6. The method of claim 5, wherein the high plasticity high silicon silicon steel is prepared by the steps of: In step S1, the melting temperature is 1600-1650°C; in step S2, the temperature for remelting and holding is 1550-1580°C. ​ 7. The method of claim 5, wherein the high plasticity high silicon silicon steel is prepared by the steps of: In step S3, the pressure of the injection is 0.02-0.06 MPa, the linear speed of the cooling roller is 15-30 m / s, and the distance between the nozzle and the cooling roller is 0.05-0.4 mm. ​ 8. The method of claim 5, wherein the high plasticity high silicon silicon steel is prepared by the steps of: In step S4, the total reduction rate of flat rolling is 2%-30%. ​ 9. The method of claim 5, wherein the high plasticity high silicon silicon steel is prepared by the steps of: In step S5, recrystallization annealing is carried out under hydrogen protection, the recrystallization annealing temperature is 1000-1150°C, and the holding time of recrystallization annealing is 5-30 minutes. ​ 10. High plasticity high silicon silicon steel as claimed in any one of claims 1 to 4 or obtained by the production process as claimed in any one of claims 5 to 9 for the production of an ultra-thin strip, characterized in that, The obtained ultra-thin strip has a thickness of 0.03-0.05 mm, a thickness tolerance of ≤±0.01 mm, and a surface roughness Ra of ≤0.5 μm.

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