35W550 non-oriented electrical steel and preparation method thereof

Abstract

The invention provides 35W550 non-oriented electrical steel and a preparation method thereof, and the low-cost 35W550 non-oriented electrical steel is composed of the following components in percentage by mass: less than or equal to 0.004% of C, 0.90%-1.10% of Si, 0.20%-0.40% of Als, 0.20%-0.40% of Mn, less than or equal to 0.002% of P, less than or equal to 0.005% of S, 0.02%-0.04% of Sb, and the balance of Fe and inevitable impurities. According to the 35W550 non-oriented electrical steel, the contents of Si, Al and P alloy elements are optimized by adjusting the element components and the contents of the element components in the 35W550 non-oriented electrical steel, the 35W550 non-oriented electrical steel meeting the market and two-wheel electric vehicle motor use requirements is manufactured, and the alloy cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of non-oriented electrical steel manufacturing, and in particular to a 35W550 non-oriented electrical steel and a preparation method thereof. Background Art

[0002] The driving motors of some vehicles (such as two-wheeled electric motorcycles) usually use non-oriented electrical steel to make the iron core. With the promotion of the national new energy strategy and the continuous competition among the leading two-wheeled electric vehicle companies, running farther has become an important indicator direction pursued by two-wheeled electric vehicles, so higher requirements are placed on the efficiency of the motor. In recent years, the grades of electrical steel used in electric motorcycle motors have gradually increased, and 35W550 is one of the grades currently used by electric motorcycle companies.

[0003] In the national standard classification of electrical steel, electrical steel with iron loss lower than 4.0W / kg is considered as high-grade electrical steel. In the previous process, high-grade non-oriented electrical steel often needs to be produced through normalization treatment. With the improvement of smelting level and control process in recent years, the iron loss value of electrical steel is constantly decreasing at the same silicon-aluminum content. At present, the actual iron loss requirements of 35W550 grade in the market are P1.5 / 50HZ value <3.4W / kg, and magnetic induction B50 value >1.69T (test density 7.75g / cm3). For non-oriented electrical steel of this performance level, in the previous manufacturing method, silicon-aluminum alloy is usually improved, and the hot-rolled plate is normalized to obtain lower iron loss. At the same time, due to the high silicon-aluminum content, single-frame cold rolling is usually used, and the strip breakage rate is high when continuous rolling is used. Summary of the invention

[0004] The embodiments of the present application provide a 35W550 non-oriented electrical steel and a preparation method thereof, aiming to produce a 35W550 product that meets market performance requirements and practical applications at a relatively low production cost.

[0005] In a first aspect, an embodiment of the present application provides a 35W550 non-oriented electrical steel, which is composed of the following components by mass fraction: C: ≤0.004%, Si: 0.90%~1.10%, Als: 0.20%~0.40%, Mn: 0.20%~0.40%, P: ≤0.002%, S: ≤0.005%, Sb: 0.02%~0.04%, and the rest is Fe and unavoidable impurities.

[0006] According to the embodiment of the first aspect of the present application, the iron loss P of 35W550 non-oriented electrical steel is 1.5 / 50HZ Value <3.30W / kg, magnetic induction B 50 Value>1.69T.

[0007] In a second aspect, an embodiment of the present application provides a method for preparing 35W550 non-oriented electrical steel, which is used to prepare the above-mentioned 35W550 non-oriented electrical steel, comprising the following steps:

[0008] Continuously casting to obtain a casting billet, the casting billet is composed of the following components by mass fraction: C: ≤0.004%, Si: 0.90%-1.10%, Als: 0.20%-0.40%, Mn: 0.20%-0.40%, P: ≤0.002%, S: ≤0.005%, Sb: 0.02%-0.04%, and the rest is Fe and unavoidable impurities;

[0009] The ingot is subjected to hot rolling, cold rolling and annealing treatment to obtain low-cost 35W550 non-oriented electrical steel, wherein the hot rolling treatment adopts a coiling temperature of more than 700°C, the annealing treatment adopts an annealing temperature of more than 960°C, the holding time in the annealing treatment is 40s to 45s, and the reduction rate of the cold rolling treatment is 80-85%.

[0010] According to an embodiment of the second aspect of the present application, the coiling temperature in the hot rolling process is 700°C to 740°C.

[0011] According to the embodiment of the second aspect of the present application, the annealing temperature in the annealing process is 960°C to 970°C.

[0012] According to an embodiment of the second aspect of the present application, the heating time in the annealing treatment is ≤30s.

[0013] According to an embodiment of the second aspect of the present application, the final reduction ratio in the cold rolling process is ≤10%.

[0014] Compared with the prior art, this application has at least the following beneficial effects:

[0015] The present application adjusts the element components and contents in 35W550 non-oriented electrical steel, optimizes the contents of Si, Al, and P alloy elements, and manufactures 35W550 non-oriented electrical steel that meets the market and two-wheeled electric vehicle motor use requirements, thereby reducing alloy costs. DETAILED DESCRIPTION

[0016] The following embodiments further describe the implementation of the present application in detail. The detailed description of the following embodiments is used to illustrate the principle of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0017] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" does not require verticality in the strict sense, but may include allowable errors. "Parallel" does not require parallelism in the strict sense, but may include allowable errors.

[0018] In the national standard classification of electrical steel, electrical steel with iron loss less than 4.0W / kg is considered high-grade electrical steel. In the past, high-grade non-oriented electrical steel often needs to be produced through normalization. With the improvement of smelting level and control process in recent years, the iron loss value of electrical steel is constantly decreasing at the same silicon and aluminum content. At present, the actual iron loss requirements of 35W550 grade in the market are P1.5 / 50HZ value <3.4W / kg, magnetic induction B50 value >1.69T (test density 7.75g / cm 3 ). For non-oriented electrical steel of this performance level, the previous manufacturing method usually adopts the method of improving silicon-aluminum alloy and normalizing the hot-rolled plate to obtain lower iron loss. At the same time, due to the high silicon-aluminum content, single-frame cold rolling is usually used, and the strip breakage rate is high when continuous rolling is used. In previous application scenarios, due to the need to consider the performance of such products after secondary annealing after punching (mainly used in industries such as compressors), the products are often not annealed sufficiently in the annealing process to obtain larger grains. The magnetic properties at the time of leaving the factory are not fully utilized, which also limits the idea of ​​product design.

[0019] The present application provides a 35W550 grade electrical steel suitable for two-wheel electric vehicle hub motors and a method for manufacturing the same: by designing a new alloy composition, adopting a special hot rolling process, performing cold continuous rolling without normalizing treatment, and adopting a high-temperature and long-time annealing process, a 35W550 product that meets market performance requirements and practical applications is produced at a relatively low production cost.

[0020] 35W550 non-oriented electrical steel

[0021] In a first aspect, an embodiment of the present application provides a 35W550 non-oriented electrical steel, which is composed of the following components by mass fraction: C: ≤0.004%, Si: 0.90%~1.10%, Als: 0.20%~0.40%, Mn: 0.20%~0.40%, P: ≤0.002%, S: ≤0.005%, Sb: 0.02%~0.04%, and the rest is Fe and unavoidable impurities.

[0022] In the previous production method, in order to make the magnetic properties of non-oriented electrical steel meet the iron loss P 1.5 / 50HZ In order to meet the requirements of value <3.4W / kg and magnetic induction B50 value >1.69T, the silicon aluminum alloy content and manganese content are usually increased. For example, the Si content needs to be more than 1.5%, the Al content needs to be more than 0.4%, and the Mn content needs to be more than 0.4%, so the production cost is relatively high.

[0023] The embodiment of the present application adjusts the element components and contents in 35W550 non-oriented electrical steel, optimizes the contents of Si, Al, and P alloy elements, reduces the content of silicon-aluminum alloy in the steel, and manufactures 35W550 non-oriented electrical steel that meets the market and two-wheeled electric vehicle motor requirements, thereby reducing the alloy cost.

[0024] Next, the role of each chemical component of 35W550 non-oriented electrical steel is described in detail:

[0025] Carbon: C: ≤ 0.004% can reduce carbide inclusions and reduce iron loss; reducing the C content can also reduce magnetic aging; a lower C content can also increase the phase transition temperature of the material and create conditions for high-temperature annealing. For example, the carbon content is 0.001%, 0.002%, 0.003%, 0.004%, or a range consisting of any two of the above values.

[0026] Silicon: Si can increase resistivity and reduce iron loss. As a main alloying element, the Si content is set to 0.90% to 1.10% after considering the balance between performance and cost. For example, the silicon content is 0.90%, 0.92%, 0.94%, 0.96%, 0.98%, 1.00%, 1.02%, 1.04%, 1.06%, 1.08%, 1.10% or a range consisting of any two of the above values.

[0027] Aluminum: Als can increase resistivity and reduce iron loss. As a main alloying element, the Als content is set to 0.20% to 0.40% after considering the balance between performance and cost. For example, the aluminum content is 0.20%, 0.22%, 0.24%, 0.26%, 0.28%, 0.30%, 0.32%, 0.34%, 0.36%, 0.38%, 0.40% or a range consisting of any two of the above values.

[0028] Manganese: Mn can improve the thermoplasticity of the material, facilitate production and processing, and eliminate the adverse effects of S elements to a certain extent. As the main alloying element, the Mn content is set to 0.20% to 0.40% after considering the balance between performance and cost. For example, the manganese content is 0.20%, 0.22%, 0.24%, 0.26%, 0.28%, 0.30%, 0.32%, 0.34%, 0.36%, 0.38%, 0.40% or a range consisting of any two of the above values.

[0029] Phosphorus: P is mainly used as an element to adjust the hardness of the product. Its content setting depends on the influence of other elements on the hardness of the product. After comprehensive consideration, the P content is set to ≤0.002%. For example, the phosphorus content is 0.001%, 0.002% or a range consisting of any two of the above values.

[0030] Antimony: Sb can improve the texture and help improve the magnetic properties of the product. After comprehensive consideration, the Sb content is set to 0.02% to 0.04%. For example, the antimony content is 0.02%, 0.022%, 0.024%, 0.026%, 0.028%, 0.03%, 0.032%, 0.034%, 0.036%, 0.038%, 0.04% or a range consisting of any two of the above values.

[0031] Among the performance indicators of traditional electrical steel, the iron loss value P1.5 / 50HZ value measured at 1.5T magnetic density and 50HZ alternating frequency and the magnetic induction intensity B50 value at 5000A / m magnetic field strength are the main magnetic performance indicators.

[0032] The iron loss of non-oriented electrical steel is mainly composed of hysteresis loss and eddy current loss. At lower frequencies, hysteresis loss usually accounts for about 70%, while at high frequencies, eddy current loss accounts for a sharp increase. Larger grain size and fewer impurity elements are conducive to reducing hysteresis loss, while smaller grain size, higher resistivity and thinner thickness are conducive to reducing eddy current loss. This contradictory characteristic makes different application needs put forward different requirements for the manufacture of electrical steel.

[0033] For two-wheeled electric vehicles, the new national standard for electrical steel motorcycles released in 2023 requires that the design speed should not exceed 50km / h. Calculated based on the average size of motorcycle tires of 405mm-510mm, the maximum wheel speed is <600 rpm. The driving motor used in electric motorcycles is mainly a hub motor, which is a permanent magnet synchronous motor. The corresponding magnetic field change frequency at this speed is <20HZ. It can be seen that the motor of the electric motorcycle is actually running at a lower alternating frequency. For the design of electrical steel, at this time, we can focus on increasing the grain size and the cleanliness of the molten steel to obtain lower hysteresis losses. The application scenario is insensitive to eddy current losses, and it is possible to consider appropriately reducing the silicon aluminum content to provide new ideas for product design. In this application, the low-cost 35W550 non-oriented electrical steel has an iron loss P1.5 / 50HZ value of <3.3W / kg, and a magnetic induction B50 value of >1.69T (test density 7.75g / cm 3 ).

[0034] In some embodiments, the iron loss P of low-cost 35W550 non-oriented electrical steel is 1.5 / 50HZ Value <3.3W / kg, magnetic induction B 50 Value>1.69T.

[0035] The embodiment of the present application adjusts the element components and their contents in 35W550 non-oriented electrical steel and optimizes the contents of Si, Al, and P alloy elements so that the magnetic properties of the steel can meet the above requirements.

[0036] Preparation method of 35W550 non-oriented electrical steel

[0037] In a second aspect, the present application provides a method for preparing low-cost 35W550 non-oriented electrical steel, and the method for preparing the above-mentioned 35W550 non-oriented electrical steel comprises the following steps:

[0038] S1: continuous casting to obtain a cast billet, the cast billet consisting of the following components by mass fraction: C: ≤0.004%, Si: 0.90%-1.10%, Als: 0.20%-0.40%, Mn: 0.20%-0.40%, P: ≤0.002%, S: ≤0.005%, Sb: 0.02%-0.04%, and the rest is Fe and unavoidable impurities;

[0039] S1: The ingot is subjected to hot rolling, cold rolling and annealing treatment to obtain low-cost 35W550 non-oriented electrical steel, wherein the hot rolling treatment adopts a coiling temperature of more than 700°C, the annealing treatment adopts an annealing temperature of more than 960°C, the holding time in the annealing treatment is 40s-45s, and the reduction rate of the cold rolling treatment is 80-85%.

[0040] In step S1, by adjusting the element components and their contents in the 35W550 non-oriented electrical steel, the contents of Si, Al, and P alloy elements are optimized, the content of silicon-aluminum alloy in the steel is reduced, and the 35W550 non-oriented electrical steel that meets the market and the requirements for the use of two-wheeled electric vehicle motors is manufactured, thereby reducing the alloy cost.

[0041] In step S2, the ingot is subjected to hot rolling, cold rolling and annealing treatment to obtain low-cost 35W550 non-oriented electrical steel.

[0042] The hot rolling treatment adopts a coiling temperature of more than 700°C. The reason for setting the coiling temperature above 700°C is that coiling above 700°C can play a role similar to normalizing annealing, coarsening harmful precipitates in the steel and reducing their adverse effects on the subsequent cold rolling annealing process.

[0043] In previous application scenarios, due to the need to consider the performance of such products after secondary annealing after punching (mainly used in industries such as compressors), the products are often not annealed sufficiently in the annealing process to obtain larger grains, and the magnetic properties are not fully utilized when leaving the factory, which also limits the idea of ​​product design. In view of the above problems, the preparation method of the embodiment of the present application adds an annealing step during the preparation process to perform sufficient annealing.

[0044] In the embodiment of the present application, the annealing treatment adopts an annealing temperature of 960°C or higher, and the annealing temperature of 960°C or higher is set to allow the grains to grow fully and reduce the iron loss of the finished product. The use of a higher annealing temperature increases the atomic diffusion rate, accelerates the grain boundary migration speed, and makes it easier for grain growth to occur.

[0045] Within a certain range, as the annealing time increases, atoms have more time to diffuse and rearrange, and the grain size will increase. However, too long an annealing time will affect product performance. Therefore, the holding time in the annealing treatment in the embodiment of the present application is 40s to 45s. The holding time of 40s to 45s allows the grains to grow fully and reduces the iron loss of the finished product. Exemplarily, the holding time is 40s, 41s, 42s, 43s, 44s or 45s.

[0046] The reduction ratio of the cold rolling process is 80-85%, and the reduction ratio is set to 80-85% in order to obtain sufficient cold rolling energy storage. Exemplarily, the reduction ratio is 80%, 81%, 82%, 83%, 84% or 85%.

[0047] The 35W550 electrical steel in this application optimizes the alloy scheme and reduces the alloy cost while meeting the market and two-wheeled electric vehicle motor requirements. The hot-rolled plate does not require regular annealing treatment, which effectively reduces the process cost. The product is cold-rolled, which effectively improves production efficiency and effectively reduces manufacturing costs.

[0048] According to an embodiment of the second aspect of the present application, the coiling temperature in the hot rolling process is 700°C to 740°C. The reason for setting the coiling temperature to 700°C to 740°C is that coiling above 700°C coarsens harmful precipitates in the steel, reducing their adverse effects on the subsequent cold rolling annealing process. Exemplarily, the coiling temperature is 700°C, 705°C, 710°C, 715°C, 720°C, 725°C, 730°C, 735°C or 740°C.

[0049] According to an embodiment of the second aspect of the present application, the annealing temperature in the annealing process is 960° C. to 970° C. When the annealing temperature is 960° C. to 970° C., the grains will further grow by grain boundary migration and mutual annealing. Exemplarily, the annealing temperature in the annealing process is 960° C., 962° C., 964° C., 966° C., 968° C. or 970° C.

[0050] According to an embodiment of the second aspect of the present application, the heating time in the annealing treatment is ≤30s.

[0051] The heating time ≤ 30 seconds is to reduce the formation of unfavorable texture and reduce the influence of unfavorable texture on the magnetic properties of the product. Exemplarily, the heating time in the annealing treatment is 15 seconds, 16 seconds, 17 seconds, 18 seconds, 19 seconds, 20 seconds, 21 seconds, 22 seconds, 23 seconds, 24 seconds, 25 seconds, 26 seconds, 27 seconds, 28 seconds, 29 seconds or 30 seconds.

[0052] According to an embodiment of the second aspect of the present application, the final reduction ratio in the cold rolling process is ≤10%. Exemplarily, the final reduction ratio is 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0053] Residual stress will be generated during the cold rolling process, and excessive reduction rate will lead to increased residual stress. When the reduction rate of the last cold rolling is low, the deformation of the steel plate is relatively mild, and the residual stress generated is small, which helps to improve the dimensional stability of the steel plate and reduce deformation, cracking and other problems caused by the release of residual stress during subsequent processing or use. A low reduction rate in the last cold rolling can also reduce the impact of factors such as rolling force fluctuations on the thickness of the steel plate, and is more conducive to ensuring the thickness accuracy of the product through a high-precision reduction system and an advanced thickness automatic control system, making the thickness of the steel plate more uniform and consistent, and obtaining a better plate shape.

[0054] Example

[0055] The following examples describe the disclosure of the present application in more detail, and these examples are intended for illustrative purposes only, as various modifications and variations within the scope of the disclosure of the present application will be apparent to those skilled in the art. Unless otherwise stated, all ingredients, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0056] Example 1

[0057] A low-cost 35W550 non-oriented electrical steel, the composition is (wt%): C: 0.0035%, Si: 0.98%, Als: 0.28%, Mn: 0.35%, P: 0.01%, S: 0.003%, Sb: 0.035%, the rest is Fe and unavoidable impurities. The preparation method is as follows:

[0058] After desulfurization, converter smelting, RH refining and alloying, the composition of the continuous casting tundish is measured as (wt%): C: 0.0035%, Si: 0.98%, Als: 0.28%, Mn: 0.35%, P: 0.01%, S: 0.003%, Sb: 0.035%, and the rest is Fe and unavoidable impurities.

[0059] After heating, rough rolling, finish rolling and laminar cooling, the coiling temperature of the slab is 700℃, and the hot rolling thickness is 2.2mm. The hot-rolled strip is straightened, scaled and pickled, and there is no iron oxide residue on the surface of the strip. A 5-stand UCM rolling mill is used for cold rolling, with a total reduction rate of 84%, including an 8% reduction rate at the last stand, and a final rolling thickness of 0.35mm. The cold-rolled strip is annealed on the annealing coating line, with an annealing temperature of 960℃, a heating time of 28S, and a holding time of 40S. The annealed strip is sintered by coating to obtain the finished product.

[0060] Product performance results are: P 1.5 / 50HZ Value 3.30W / kg, magnetic induction B 50 Value = 1.707T (test density 7.75g / cm 3 ).

[0061] After the product is used by downstream motor customers, the motor power, torque and efficiency are qualified.

[0062] Example 2

[0063] A low-cost 35W550 non-oriented electrical steel, the composition is (wt%): C: 0.0030%, Si: 1.10%, Als: 0.29%, Mn: 0.30%, P: 0.095%, S: 0.003%, Sb: 0.035%, the rest is Fe and unavoidable impurities. The preparation method is as follows:

[0064] After desulfurization, converter smelting, RH refining and alloying, the composition of the continuous casting tundish is measured as (wt%): C: 0.0030%, Si: 1.10%, Als: 0.29%, Mn: 0.30%, P: 0.095%, S: 0.003%, Sb: 0.035%, and the rest is Fe and unavoidable impurities. After heating, rough rolling, finish rolling and laminar cooling, the slab is coiled at 720℃ and the hot rolling thickness is 2.3mm. The hot-rolled strip is straightened, scaled and pickled, and there is no iron oxide residue on the surface of the strip. A 5-stand UCM rolling mill is used for cold rolling, with a total reduction rate of 85%, of which the last stand reduction rate is 8%, and the final rolling of the strip is 0.35mm. The cold-rolled strip is annealed on the annealing coating line, with an annealing temperature of 970℃, a heating time of 27S, and a holding time of 40S. The annealed strip is then coated and sintered to obtain the finished product.

[0065] Product performance results are: P 1.5 / 50HZ Value 3.15W / kg, magnetic induction B 50 Value = 1.702T (test density 7.75g / cm 3 ).

[0066] After the product is used by downstream motor customers, the motor power, torque and efficiency are qualified.

[0067] Example 3

[0068] A low-cost 35W550 non-oriented electrical steel, the composition is (wt%): C: 0.0032%, Si: 1.15%, Als: 0.30%, Mn: 0.42%, P: 0.0105%, S: 0.0035%, Sb: 0.04%, the rest is Fe and unavoidable impurities. The preparation method is as follows:

[0069] After desulfurization, converter smelting, RH refining and alloying, the composition of the continuous casting tundish was measured as (wt%): C: 0.0032%, Si: 1.15%, Als: 0.30%, Mn: 0.42%, P: 0.0105%, S: 0.0035%, Sb: 0.04%, and the rest was Fe and unavoidable impurities.

[0070] After heating, rough rolling, finishing rolling and laminar cooling, the coiling temperature of the slab is 720℃, and the hot rolling thickness is 2.2mm. The hot-rolled strip is straightened, scaled and pickled, and there is no iron oxide scale left on the surface of the strip. A 5-stand UCM rolling mill is used for cold rolling, with a total reduction rate of 84%, including an 8% reduction rate for the last stand, and a final rolling thickness of 0.35mm. The cold-rolled strip is annealed on the annealing coating line, with an annealing temperature of 960℃, a heating time of 28S, and a holding time of 42S. The annealed strip is sintered by coating to obtain the finished product.

[0071] Product performance results are: P 1.5 / 50HZ Value 3.10W / kg, magnetic induction B 50 Value = 1.698T (test density 7.75g / cm 3 ).

[0072] After the product is used by downstream motor customers, the motor power, torque and efficiency are qualified.

[0073] Comparative Example 1

[0074] The difference between Comparative Example 1 and Example 1 is that when the cold-rolled strip is annealed on the annealing coating line, the annealing temperature is 930°C.

[0075] Product performance results are: P 1.5 / 50HZ Value 3.4W / kg, magnetic induction B 50 Value = 1.670T (test density 7.75g / cm 3 ).

[0076] Comparative Example 2

[0077] The difference between Comparative Example 2 and Example 1 is that when the cold-rolled strip is annealed on the annealing coating line, the holding time is 35S.

[0078] Product performance results are: P 1.5 / 50HZ Value 3.3W / kg, magnetic induction B 50 Value = 1.699T (test density 7.75g / cm 3 ).

[0079] Comparative Example 3

[0080] The difference between Comparative Example 3 and Example 1 is that when the cold-rolled strip is annealed on the annealing coating line, the holding time is 60S.

[0081] Product performance results are: P 1.5 / 50HZ Value 3.1W / kg, magnetic induction B 50 Value = 1.695T (test density 7.75g / cm 3 ).

[0082] However, too long insulation time will cause waste of resources and increase costs.

[0083] In summary, by designing a new alloy composition, adopting a special hot rolling process, cold rolling without normalizing treatment, and taking a high-temperature and long-time annealing process, 35W550 products that meet market performance requirements and practical applications can be produced at a lower production cost.

[0084] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A 35W550 non-oriented electrical steel, characterized in that: The following components are calculated by mass fraction: composition: C: ≤0.004%, Si: 0.90%~1.10%, Als: 0.20%~0.40%, Mn: 0.20%~0.40%, P: ≤0.002%, S: ≤0.005%, Sb: 0.02%~0.04%, and the rest are Fe and unavoidable impurities.

2. The 35W550 non-oriented electrical steel according to claim 1, characterized in that: The iron loss P of the 35W550 non-oriented electrical steel 1.5 / 50HZ Value <3.30W / kg, magnetic induction B 50 Value>1.69T.

3. A method for preparing 35W550 non-oriented electrical steel, used for preparing the 35W550 non-oriented electrical steel according to any one of claims 1 to 2, characterized in that: The steps include: Continuously casting to obtain a casting billet, wherein the casting billet is composed of the following components by mass fraction: C: ≤0.004%, Si: 0.90%-1.10%, Als: 0.20%-0.40%, Mn: 0.20%-0.40%, P: ≤0.002%, S: ≤0.005%, Sb: 0.02%-0.04%, and the rest is Fe and unavoidable impurities; The ingot is subjected to hot rolling, cold rolling and annealing treatment to obtain low-cost 35W550 non-oriented electrical steel, wherein the hot rolling treatment adopts a coiling temperature of ≥700°C, the annealing treatment adopts an annealing temperature of ≥960°C, the holding time in the annealing treatment is 40s-45s, and the reduction rate of the cold rolling treatment is 80-85%.

4. The preparation method according to claim 3, characterized in that: The coiling temperature in the hot rolling process is 700°C to 740°C.

5. The preparation method according to claim 3, characterized in that: The annealing temperature in the annealing process is 960° C. to 970° C.

6. The preparation method according to claim 5, characterized in that: The heating time in the annealing treatment is ≤30s.

7. The preparation method according to claim 3, characterized in that: The final reduction ratio in the cold rolling process is ≤10%.