Manufacturing method for non-oriented electrical steel

Abstract

This patent relates to a method for manufacturing non-oriented electrical steel sheets, which includes the step of warm rolling a hot-rolled steel sheet, wherein the warm rolling consists of at least three rolling passes: - The first rolling pass is performed at an entry temperature of the steel sheet between 70°C and 140°C; - The second rolling pass is performed at an entry temperature of the steel sheet between 90°C and 210°C, which is higher than the entry temperature of the first rolling pass; - The third rolling pass is performed at an entry temperature of the steel sheet between 190°C and 250°C, which is higher than the entry temperature of the second rolling pass; - The remaining rolling passes are performed at an entry temperature of the steel sheet between 50°C and 100°C.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing non-oriented electrical steel. Specifically, the present invention relates to a method that enables the production of fully recrystallized ferritic non-oriented electrical steel that achieves good magnetic properties, particularly with respect to polarization.

[0002] U.S. Patent Application Publication No. 20150213928 A1 discloses a method for manufacturing high-strength electrical steel sheets having excellent magnetic properties such as low iron loss.

[0003] The steel composition, in weight percent, includes a high silicon content of 3.5-4.5%, a carbon content of 0.005% or less, a manganese content of 0.01%-0.10%, an aluminum content of 0.005% or less, a calcium content of 0.0010%-0.0050%, a sulfur content of 0.0030% or less, and a nitrogen content of 0.0030% or less, with the remainder being fe and incidental impurities. The plate thickness is 0.40 mm or less, and the non-recrystallized deformation microstructure accounts for 10%-70%.

[0004] The manufacturing process includes hot band annealing at 900°C to 1000°C and warm rolling at several hundred degrees Celsius to reduce sheet breakage.

[0005] The inventors of this invention use a non-recrystallized recovery microstructure as a means of strengthening steel sheets without using precipitates such as carbonitrides. In this patent application, components other than Si are reduced as much as possible in order to reduce variations in the resulting microstructure and tensile strength.

[0006] However, the method disclosed in this patent cannot exhibit the effect of a second rolling process, such as warm rolling, on the magnetic properties. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent Application Publication No. 20150213928, Specification A1 [Overview of the project] [Problems that the invention aims to solve]

[0008] The object of the present invention is to improve the polarization of non-oriented electrical steel by improving the texture that can be obtained by the claimed rolling process. [Means for solving the problem]

[0009] The present invention is a method for manufacturing non-oriented electrical steel sheets, comprising the following steps: - A process to provide a steel composition containing the following elements, expressed in weight percent: 0.0001% ≤ Carbon ≤ 0.008% 0.1% ≤ Manganese ≤ 2.0% 2.6% ≤ Silicon ≤ 6.5% 0.1% ≤ Aluminum ≤ 1.2% 0% ≤ Phosphorus ≤ 0.15% 0% ≤ Sulfur ≤ 0.006% 0% ≤ Nitrogen ≤ 0.09% Along with, 3.5% ≤ Si + Al + Mn ≤ 9.5% Furthermore, any of the following optional elements 0% ≤ Niobium ≤ 0.1% 0% ≤ Titanium ≤ 0.1% 0% ≤ Vanadium ≤ 0.1% 0% ≤ Chromium ≤ 1% 0% ≤ Molybdenum ≤ 0.5% 0% ≤ Tungsten ≤ 0.1% 0% ≤ Cobalt ≤ 1% 0% ≤ Arsenic ≤ 0.05% 0% ≤ Calcium ≤ 0.01% 0%≦Copper≦1% 0% ≤ Nickel ≤ 1% 0% ≤ Boron ≤ 0.05% 0%≦Lead≦0.2% 0% ≤ Tin ≤ 0.2% 0% ≤ Antimony ≤ 0.2% It can include one or more of the following: The composition of the remainder consists of iron and unavoidable impurities generated by the treatment, - a step of reheating the semi-finished product to a temperature of 1050°C to 1250°C, - a step of hot rolling the semi-finished product, wherein the hot rolling finishing temperature is 750°C to 950°C, which is for obtaining a hot-rolled steel sheet, - after completion of hot rolling, a step of cooling the hot-rolled sheet to a coiling temperature range of 450°C to 750°C at a cooling rate of at least 10°C / sec, - thereafter, a step of coiling the hot-rolled steel sheet within the coiling temperature range of 450°C to 750°C, - optionally, a step of performing a descaling step on the hot-rolled steel sheet, - hot band annealing is optionally performed on the hot-rolled steel sheet at 650°C to 1100°C for 10 seconds to 96 hours, - optionally, a step of performing a descaling treatment on the hot-rolled steel sheet, - a step of warm rolling the hot-rolled steel sheet, wherein the warm rolling includes at least three rolling passes, - the first rolling pass is performed at an entry temperature of the steel sheet of 70°C to 140°C, - the second rolling pass is performed at an entry temperature of the steel sheet of 90°C to 210°C, which is higher than the entry temperature of the first rolling pass, - the third rolling pass is performed at an entry temperature of the steel sheet of 190°C to 250°C, which is higher than the entry temperature of the second rolling pass, - the remaining rolling passes are performed at an entry temperature of the steel sheet of 50°C to 100°C; the warm rolling, - thereafter, a step of annealing the warm-rolled steel sheet, wherein heating for annealing starts from room temperature to an annealing temperature range Tsoak of 800°C to 1100°C at a heating rate HR1 of at least 1°C / sec, - next, a step of performing annealing at the annealing temperature for 10 to 5000 seconds so as to ensure 100% recrystallization, - next, cooling the warm-rolled steel sheet from the annealing temperature to a temperature T1 of 300°C to 20°C at a cooling rate CR1 of 1°C / sec to 150°C / sec, a step of subsequently cooling to room temperature to obtain a non-oriented electrical steel sheet, the method comprising the above step. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Chemical Composition> The chemical composition of the non-oriented electrical steel according to the present invention comprises the following elements:

[0011] The carbon content in the steel of the present invention is 0.0001 to 0.008 weight percent.

[0012] Carbon is an element that forms precipitates, which are detrimental to the magnetic properties of the steel. Since carbon promotes magnetic aging, the preferred content of carbon according to the present invention is 0.0001 to 0.006 weight percent, more preferably 0.0001 to 0.005 weight percent.

[0013] The manganese content in the steel of the present invention is 0.1 to 2 weight percent.

[0014] Manganese provides solid solution strengthening and reduces iron loss by increasing specific resistance.

[0015] Preferably, the manganese content in the steel of the present invention is 0.1 to 1.2 weight percent. Even more preferably, the manganese content in the steel of the present invention is 0.1 to 0.5 weight percent.

[0016] Alternatively, the manganese content in the steel of the present invention is 0.5 to 2.0 weight percent.

[0017] The silicon content in the steel of the present invention is 2.6 to 6.5 weight percent.

[0018] Silicon is an element that contributes to increased strength through solid solution strengthening and is an important element for increasing the resistivity of steel and reducing eddy current losses in iron loss. The above-mentioned effects require a minimum silicon content of at least 2.6 weight percent. However, if the silicon content exceeds 3.5 weight percent, rolling becomes difficult and the magnetic induction of the steel decreases significantly. The preferred limit for the presence of silicon is 2.6 to 5.0 weight percent, more preferably 2.8 to 4.0 weight percent.

[0019] The aluminum content in the steel of this invention is 0.1 to 1.2 weight percent.

[0020] Aluminum can increase the electrical resistivity of the material and effectively reduce iron loss in steel. When the aluminum content exceeds 1.2 weight percent, the magnetic induction of the steel in the present invention is significantly reduced. The preferred limit for the aluminum content is 0.7 to 1.2 weight percent, more preferably 0.8 to 1.1 weight percent.

[0021] Alternatively, a preferred limit for the aluminum content is 0.4–0.7 weight percent.

[0022] The non-oriented electrical steel sheet according to the present invention is required to contain silicon, manganese, and aluminum in a total content of 3.5 to 9.5 weight percent. If the total content of Si, Mn, and Al is less than 3.5 weight percent, it is impossible to achieve both magnetic properties and mechanical properties in both the transverse and rolling directions. However, if the total content of Si, Mn, and Al exceeds 9.5 weight percent, the steel hardens and becomes difficult to roll.

[0023] More preferably, the total content of Si, Mn, and Al is 3.5 to 5.5 weight percent.

[0024] The phosphorus content in the steel of this invention is 0 to 0.15 weight percent.

[0025] Phosphorus tends to segregate, particularly at grain boundaries, or co-segregate with manganese, thus reducing hot and cold ductility. For these reasons, its content is 0.15% by weight or less, preferably less than 0.09% by weight.

[0026] Sulfur is not an essential element, but it may be present in the steel as an impurity. From the viewpoint of the present invention, preferably, the sulfur content is kept to the minimum possible, but less than 0.006 weight percent from the viewpoint of manufacturing cost. Furthermore, if more sulfur is present in the steel, the sulfur will combine to form sulfides that are detrimental to the magnetic properties of the present invention.

[0027] Nitrogen is not an essential element, but it may be present in steel as an impurity. To minimize the precipitation of aluminum nitride during solidification, which is detrimental to the magnetic properties of steel, the nitrogen content should be 0.09% or less.

[0028] Niobium is an optional element, and its content in the steel of this invention is 0 to 0.1 weight percent.

[0029] Niobium is suitable for forming carbonitrides to increase the strength of the steel of this invention through precipitation hardening. Niobium also influences the size of the microstructure components by precipitating as carbonitrides. However, niobium content exceeding 0.1 weight percent is not of economic interest due to the saturation effect.

[0030] Titanium is an optional element in the steel composition of the present invention. The titanium content in the steel of the present invention is 0 to 0.1 weight percent.

[0031] Titanium forms titanium nitrides that appear during the solidification of the casting. The amount of titanium is limited to 0.1 weight percent to limit the formation of titanium nitrides that are detrimental to the magnetic properties of the steel of this invention.

[0032] Vanadium is an optional element, and its content in the steel of this invention is 0 to 0.1 weight percent.

[0033] Vanadium is effective in increasing the strength of steel by forming carbides or carbonitrides, and from an economic standpoint, the upper limit is 0.1 weight percent.

[0034] Chromium is an optional element in the steel composition of the present invention. The chromium content in the steel of the present invention is 0 to 1 weight percent.

[0035] Chromium strengthens steel through solid solution reinforcement, but using more than 1% by weight will impair the surface finish of the steel.

[0036] Molybdenum is an optional element in the steel composition of the present invention. The molybdenum content in the steel of the present invention is 0 to 0.5 weight percent.

[0037] Molybdenum clearly coarses carbides, thus reducing iron loss. While not bound by theory, the effect of improving iron loss saturates above 0.5 weight percent.

[0038] Tungsten is an optional element in the steel composition of the present invention. The tungsten content in the steel of the present invention is 0 to 0.1 weight percent.

[0039] Clearly, tungsten, like molybdenum, has the effect of coarsening carbides and reducing iron loss. Although not bound by theory, the above effect is not sufficiently obtained when the addition amount is less than 0.001 weight percent, while the improvement in iron loss saturates when it exceeds 0.1 weight percent.

[0040] Cobalt is an optional element in the steel composition of the present invention. The cobalt content in the steel of the present invention is 0 to 1 weight percent.

[0041] While not bound by theory, cobalt is an element that increases the magnetic moment of Fe alloys, thereby increasing magnetic flux density and reducing iron loss. However, if the amount added is less than 0.01 weight percent, the above effects are not sufficiently obtained, while exceeding 1 weight percent significantly increases the cost of the raw materials.

[0042] Arsenic is an optional element in the steel composition of the present invention. The arsenic content in the steel of the present invention is 0 to 0.05 weight percent.

[0043] Although not bound by theory, arsenic is a grain boundary segregating element and has the effect of improving texture and thus reducing iron loss. The above effect can be obtained by adding 0.001 weight percent or more. Although not bound by theory, arsenic is an element that causes grain boundary embrittlement, and this adverse effect becomes particularly pronounced when added in amounts exceeding 0.05 weight percent. Therefore, it is preferable to add As in the range of 0.001 to 0.05 weight percent.

[0044] Nickel is an optional element in the steel composition of the present invention. The nickel content in the steel of the present invention is 0 to 1 weight percent.

[0045] Nickel enhances the strength of the steel of this invention, improving its strength and elongation. However, if its content exceeds 1 weight percent, nickel causes a decrease in ductility.

[0046] Copper is an optional element in the steel composition of the present invention. The copper content in the steel of the present invention is 0 to 1 weight percent.

[0047] Copper increases the strength and elongation of the steel of this invention. However, when the copper content exceeds 1 weight percent, it can obviously degrade the surface characteristics and magnetic properties by forming precipitates.

[0048] Boron is an optional element in the steel composition of the present invention. The boron content in the steel of the present invention is 0 to 0.05 weight percent.

[0049] Boron forms boron nitride, and when added in an amount of at least 0.0001 weight percent, it imparts additional strength to the steel of the present invention.

[0050] Calcium is an optional element in the steel composition of the present invention. The calcium content in the steel of the present invention is 0 to 0.01 weight percent, preferably 0.001 to 0.01 weight percent.

[0051] Clearly, calcium contributes to steel refining by binding harmful sulfur content in a spherical form, thereby delaying the harmful effects of sulfur.

[0052] Other elements, such as Sn, Pb, or Sb, may be added individually or in combination in the following proportions: Sn ≤ 0.2 weight percent, Pb ≤ 0.2 weight percent, and Sb ≤ 0.2 weight percent. These elements allow for grain refinement during solidification up to the indicated maximum content levels. The remainder of the steel composition consists of iron and unavoidable impurities arising from the process.

[0053] The method according to the present invention includes providing a semi-finished casting of steel having the chemical composition of the steel according to the present invention.

[0054] For example, casting can be carried out in the form of ingots, or in the form of thin slabs or strips, continuously, i.e., in thicknesses ranging from thin strips of several tens of millimeters to slabs of about 220 mm.

[0055] Next, the casting is reheated to a temperature of 1050°C to 1250°C.

[0056] Below 1050°C, the hot rolling temperature becomes too low, making rolling difficult and resulting in excessively high milling force. Above 1250°C, the steel becomes very soft, exhibiting some slack, and thus potentially difficult to handle.

[0057] Subsequently, the reheated slab is subjected to hot rolling to obtain hot-rolled steel sheets. The hot-rolling finishing temperature is 750°C to 950°C.

[0058] Below 750°C, recrystallization is limited, and the microstructure undergoes significant deformation. Above 950°C, the reheating temperature becomes higher, which means there will be more impurities in the solid solution, and it may also result in precipitation and deterioration of magnetic properties.

[0059] Next, the hot-rolled steel sheet is heated to at least 10°C.s. -1 At a cooling rate of 200°C / s, it is cooled to a coiling temperature of 450°C to 750°C. Preferably, the cooling rate is 200°C / s. -1 The following applies:

[0060] Below 450°C, such coiling temperatures do not allow for sufficient recovery, although this metallurgical step is necessary for magnetic properties. Above 750°C, a thick internal oxide layer appears, causing difficulties in subsequent processing steps such as hot rolling and / or pickling.

[0061] Hot-rolled steel sheets are optionally subjected to a descaling step to remove, at least partially, the scale formed during hot rolling.

[0062] Next, the coiled hot-rolled steel sheet is optionally subjected to hot band annealing. Hot band annealing is carried out at a temperature of 650°C to 1100°C for at least 10 seconds and for no more than 96 hours. Preferably, it is carried out at a temperature of 700°C to 1070°C, more preferably 720°C to 1050°C.

[0063] Optionally, the scale removal step in the annealing of this hot-rolled (hot-banded) sheet may be carried out, for example, by pickling such sheet.

[0064] <Warm rolling> Next, the hot-rolled or hand-strand annealed steel sheet is subjected to warm rolling to obtain a warm-rolled steel sheet. For example, the thickness reduction is 35-95%.

[0065] Warm rolling involves at least three rolling passes. - The first rolling pass is performed at an entry temperature of 70°C to 140°C for the steel sheet. - The second rolling pass is performed at an entry temperature of the steel sheet between 90°C and 210°C, which is higher than the entry temperature of the first rolling pass. - The third rolling pass is performed at an entry temperature of 190°C to 250°C for the steel sheet, which is higher than the entry temperature of the second rolling pass. - The remaining rolling passes are carried out at an entry temperature of 50°C to 100°C for the steel sheet.

[0066] Preferably, the first rolling pass is performed at an entry temperature of 70°C to 110°C for the steel sheet, and the second rolling pass is performed at an entry temperature of 100°C to 210°C for the steel sheet.

[0067] Preferably, the first rolling pass is performed at an entry temperature of 70°C to 110°C for the steel sheet, the second rolling pass is performed at an entry temperature of 135°C to 175°C for the steel sheet, and the third rolling pass is performed at an entry temperature of 190°C to 230°C for the steel sheet.

[0068] Preferably, the first rolling pass is performed at an entry temperature of 100°C to 140°C for the steel sheet, the second rolling pass is performed at an entry temperature of 170°C to 210°C for the steel sheet, and the third rolling pass is performed at an entry temperature of 210°C to 250°C for the steel sheet.

[0069] <Annealing> Subsequently, the warm-rolled steel sheet is heated, starting from room temperature, and the warm-rolled steel sheet is heated to at least 1°C.s. -1The material is heated at a rate of 800°C to 1100°C until it reaches the annealing temperature (Tsoak). To ensure 100% recrystallization, the warm-rolled steel sheet is held at the annealing temperature for 10 to 5000 seconds.

[0070] Preferably, the heating rate is at least 2°C.s. -1 More preferably, at least 5°C.s -1 That is the case.

[0071] Preferably, the annealing temperature Tsoak is 1000°C to 1100°C, and more preferably 1020°C to 1100°C or 1050°C to 1100°C.

[0072] Preferably, the warm-rolled steel sheet is held at the annealing temperature for at least 20 seconds. More preferably, the warm-rolled steel sheet is held at the annealing temperature for at least 20 seconds.

[0073] Next, the warm-rolled steel sheet is cooled from Tsoak to a temperature T1 in the range of 20°C to 300°C at a cooling rate CR1 of 1°C / sec to 150°C / sec. In a preferred embodiment, the cooling rate CR1 is 3°C / sec to 120°C / sec. A preferred T1 temperature is 20°C to 200°C.

[0074] The cooling of warm-rolled steel sheets can be carried out in multiple cooling steps, and these multiple cooling steps can have different cooling rates.

[0075] Subsequently, the warm-rolled steel sheet is cooled to room temperature to obtain a non-oriented electrical steel sheet.

[0076] The non-oriented electrical steel sheet of the present invention may be optionally coated with an insulating film, an organic coating, an inorganic coating, or a combination thereof, in order to improve its insulating properties.

[0077] <product> The present invention also relates to a non-oriented electrical steel sheet having a composition comprising the following elements, expressed in weight percent: 0.0001% ≤ Carbon ≤ 0.008% 0.1% ≤ Manganese ≤ 2.0% 2.6% ≤ Silicon ≤ 6.5% 0.1% ≤ Aluminum ≤ 1.2% 0% ≤ Phosphorus ≤ 0.15% 0% ≤ Sulfur ≤ 0.006% 0% ≤ Nitrogen ≤ 0.09% Along with, 3.5% ≤ Si + Al + Mn ≤ 9.5% Furthermore, any of the following optional elements 0% ≤ Niobium ≤ 0.1% 0% ≤ Titanium ≤ 0.1% 0% ≤ Vanadium ≤ 0.1% 0% ≤ Chromium ≤ 1% 0% ≤ Molybdenum ≤ 0.5% 0% ≤ Tungsten ≤ 0.1% 0% ≤ Cobalt ≤ 1% 0% ≤ Arsenic ≤ 0.05% 0.0% ≤ Calcium ≤ 0.01% 0%≦Copper≦1% 0% ≤ Nickel ≤ 1% 0% ≤ Boron ≤ 0.05% 0%≦Lead≦0.2% 0% ≤ Tin ≤ 0.2% 0% ≤ Antimony ≤ 0.2% It can include one or more of the following: The remaining composition consists of iron and unavoidable impurities resulting from the processing, and the microstructure of the steel sheet is made from ferrite and contains 100% recrystallized microstructure by area fraction, with an average grain size of 15 to 250 microns, and is given by the following formula:

[0078]

number

[0079] The area fraction and grain size are measured by the linear intercept method in accordance with ASTM E112 standard.

[0080] The texture coefficient is defined as the ratio of {100}〈uvw〉 cube fiber to {111}〈uvw〉 gamma fiber. The cube fiber and gamma fiber can be measured by XRD. For example, a diffraction goniometer is operated at 35 kV and 45 mA.

[0081] The average grain size is measured by the linear intercept method in accordance with ASTM E112 (2013) standard.

[0082] The resistivity is measured in accordance with ASTM A712-14 standard.

[0083] Preferably, the composition comprises 2.8 to 3.3 weight percent of silicon.

[0084] Preferably, the composition comprises 0.1 to 1.2 weight percent of manganese. Alternatively, the composition may comprise 0.5 to 2.0 weight percent of manganese.

[0085] The steel of the present invention has a microstructure formed of ferrite. The microstructure of the non-oriented electrical steel does not contain microstructure components such as martensite, bainite, pearlite and cementite.

[0086] The steel of the present invention has a 100% recrystallized microstructure region in terms of area fraction.

[0087] The steel of the present invention has particles having an average particle size of 15 to 250 microns. The average particle size is measured by the linear section method according to the ASTM E112 (2013) standard.

[0088] Preferably, the average particle size is 15 to 35 microns. Clearly, this particle size range is preferable for the high-speed rotor region.

[0089] Preferably, the average particle size is 35 to 80 microns. Clearly, this particle size range is preferable for the stator and high-speed rotor regions of high-frequency machinery.

[0090] Preferably, the average particle size is 80 to 120 microns. Clearly, this particle size range is preferable for the stator region where torque is used.

[0091] Preferably, the average particle size is 120 to 250 microns. Clearly, this particle size range is preferable for industrial generators and traction or propulsion motors.

[0092] Preferably, steel is given by the following formula:

[0093]

number

[0094] The present invention also relates to the use of steel plates as described above, or steel plates manufactured as described above, for the manufacture of components of electric vehicles or electrical machinery.

[0095] The present invention also relates to a vehicle or electrical machine comprising the parts obtained as described above. [Examples]

[0096] The following tests, examples, graphic illustrations, and tables presented herein are not limiting in nature and should be considered for illustrative purposes only, and illustrate advantageous features of the present invention.

[0097] Table 1 summarizes steel sheets made from steels with different compositions.

[0098] The steel plates are manufactured according to the process parameters listed in Tables 2 and 3, respectively.

[0099] Table 2 summarizes the process parameters for reheating, hot rolling, coiling, and hot band annealing.

[0100] Table 3 summarizes the process parameters for the second rolling stage, i.e., cold or warm rolling, and the final annealing stage.

[0101] Table 4 illustrates the results of tests performed on both the steel of the present invention and the reference steel.

[0102] The steel and reference steel of the present invention should be compared in pairs.

[0103] For example, references 13 and invention 16 make it possible to evaluate the claimed effects of warm rolling on texture and magnetic polarization. In fact, the other process parameters, namely hot rolling, coiling, hot band annealing, and final annealing, are the same.

[0104] The steel "Invention 16" according to the present invention has a better texture coefficient than "Reference 13," which makes it possible to obtain better magnetic polarization, and subsequently "Reference 13."

[0105] The same inferences and conclusions can be derived using the following pairs: "Reference 14" and "Invention 17", "Reference 15" and "Invention 18", "Reference 23" and "Invention 26", "Reference 24" and "Invention 27", "Reference 25" and "Invention 28", "Reference 23" and "Invention 29", "Reference 24" and "Invention 30", and "Reference 25" and "Invention 31".

[0106] As a result, it is clear that this method makes it possible to improve the polarization and texture of non-oriented electrical steel.

[0107] [Table 1] Table 1: Composition of steel in weight percent

[0108] [Table 2] Table 2: Process parameters for reheating, hot rolling, coiling, and HBA steps

[0109] [Table 3] Table 3: Process parameters for warm rolling and rolling using the latest technology

[0110] [Table 4] Table 4: Microstructure and magnetic properties

Claims

1. A method for manufacturing non-oriented electrical steel sheets, comprising the following steps: - A process to provide a steel composition containing the following elements, expressed in weight percent: 0.0001% ≤ Carbon ≤ 0.008% 0.1% ≤ Manganese ≤ 2.0% 2.6% ≤ Silicon ≤ 6.5% 0.1% ≤ Aluminum ≤ 1.2% 0% ≤ Phosphorus ≤ 0.15% 0% ≤ Sulfur ≤ 0.006% 0% ≤ Nitrogen ≤ 0.09% Also, 3.5% ≤ Si + Al + Mn ≤ 9.5% Furthermore, any of the following optional elements, 0% ≤ Niobium ≤ 0.1% 0% ≤ Titanium ≤ 0.1% 0% ≤ Vanadium ≤ 0.1% 0% ≤ Chromium ≤ 1% 0% ≤ Molybdenum ≤ 0.5% 0% ≤ Tungsten ≤ 0.1% 0% ≤ Cobalt ≤ 1% 0% ≤ Arsenic ≤ 0.05% 0% ≤ Calcium ≤ 0.01% 0%≦Copper≦1% 0% ≤ Nickel ≤ 1% 0% ≤ Boron ≤ 0.05% 0%≦Lead≦0.2% 0% ≤ Tin ≤ 0.2% 0% ≤ Antimony ≤ 0.2% It can include one or more of the following: The remaining composition consists of iron and unavoidable impurities resulting from the process. - A process of reheating the semi-finished product to a temperature of 1050°C to 1250°C. - A process for obtaining a hot-rolled steel sheet, wherein the hot-rolling finish temperature is 750°C to 950°C, - After hot rolling is completed, the hot-rolled steel sheet is cooled to a coiling temperature range of 450°C to 750°C at a cooling rate of at least 10°C / second. - Subsequently, the hot-rolled steel sheet is coiled in a coiling temperature range of 450°C to 750°C. - A step of optionally performing a scale removal treatment on the hot-rolled steel sheet, - Hot band annealing is optionally performed on hot-rolled steel sheets at 650°C to 1100°C for 10 seconds to 96 hours. - A step of optionally performing a scale removal treatment on the hot-rolled steel sheet, - A step of warm rolling the hot-rolled steel sheet, wherein the warm rolling includes at least three rolling passes, - The first rolling pass is performed at an entry temperature of 70°C to 140°C for the steel sheet. - The second rolling pass is performed at an entry temperature of 90°C to 210°C for the steel sheet, which is higher than the entry temperature of the first rolling pass. - The third rolling pass is performed at an entry temperature of 190°C to 250°C for the steel sheet, which is higher than the entry temperature of the second rolling pass. - The remaining rolling passes are warm rolling processes, which are carried out at an entry temperature of 50°C to 100°C for the steel sheet. - Subsequently, the process of annealing the warm-rolled steel sheet is to start heating for annealing from room temperature to an annealing temperature range Tsoak of 800°C to 1100°C at a heating rate HR1 of at least 1°C / second. Next, to ensure 100% recrystallization, the annealing process is carried out at an annealing temperature for 10 to 5000 seconds. Next, the process of obtaining a non-oriented electrical steel sheet is carried out by cooling the warm-rolled steel sheet from the annealing temperature to a temperature T1 from 300°C to room temperature, starting from the annealing temperature, at a cooling rate CR1 of 1°C / sec to 150°C / sec. Methods that include...

2. The method according to claim 1, wherein the first rolling pass is performed at an entry temperature of the steel sheet between 70°C and 110°C, and the second rolling pass is performed at an entry temperature of the steel sheet between 100°C and 210°C.

3. The method according to claim 1, wherein the first rolling pass is performed at an entry temperature of 70°C to 110°C for the steel sheet, the second rolling pass is performed at an entry temperature of 135°C to 175°C for the steel sheet, and the third rolling pass is performed at an entry temperature of 190°C to 230°C for the steel sheet.

4. The method according to claim 1, wherein the first rolling pass is performed at an entry temperature of 100°C to 140°C for the steel sheet, the second rolling pass is performed at an entry temperature of 170°C to 210°C for the steel sheet, and the third rolling pass is performed at an entry temperature of 210°C to 250°C for the steel sheet.

5. The method according to any one of claims 1 to 4, wherein the annealing temperature range Tsoak is 1000°C to 1100°C.

6. The method according to claim 5, wherein the annealing temperature range Tsoak is 1020°C to 1100°C.

7. The method according to claim 6, wherein the annealing temperature range Tsoak is 1050°C to 1100°C.

8. A non-oriented electrical steel sheet having a composition containing the following elements, expressed in weight percent: 0.0001% ≤ Carbon ≤ 0.008% 0.1% ≤ Manganese ≤ 2.0% 2.6% ≤ Silicon ≤ 6.5% 0.1% ≤ Aluminum ≤ 1.2% 0% ≤ Phosphorus ≤ 0.15% 0% ≤ Sulfur ≤ 0.006% 0% ≤ Nitrogen ≤ 0.09% Also, 3.5% ≤ Si + Al + Mn ≤ 9.5% Furthermore, any of the following optional elements, 0% ≤ Niobium ≤ 0.1% 0% ≤ Titanium ≤ 0.1% 0% ≤ Vanadium ≤ 0.1% 0% ≤ Chromium ≤ 1% 0% ≤ Molybdenum ≤ 0.5% 0% ≤ Tungsten ≤ 0.1% 0% ≤ Cobalt ≤ 1% 0% ≤ Arsenic ≤ 0.05% 0.0% ≤ Calcium ≤ 0.01% 0%≦Copper≦1% 0% ≤ Nickel ≤ 1% 0% ≤ Boron ≤ 0.05% 0%≦Lead≦0.2% 0% ≤ Tin ≤ 0.2% 0% ≤ Antimony ≤ 0.2% It can include one or more of the following: The remaining composition consists of iron and unavoidable impurities resulting from the processing, and the microstructure of the steel sheet is made from ferrite and contains 100% recrystallized microstructure by area fraction, with an average particle size of 15 to 250 microns, and is given by the following formula: [Math 1] Satisfying the condition, in the formula -J50 is magnetic polarization in Tesla units, -T Ｒ１ This is the warm rolling temperature at the entry side of the first pass, -T Ｒ２ This is the warm rolling temperature at the entry side of the second pass, -T Ｒ３ This is the warm rolling temperature at the entry side of the third pass. -TF is the texture coefficient, -d is the average particle size in μm units. -ρ is the resistivity in μΩ, measured in centimeters, for non-oriented electrical steel sheets.

9. The non-oriented electrical steel sheet according to claim 8, wherein the composition contains 2.6 to 5.0 weight percent silicon.

10. The non-oriented electrical steel sheet according to claim 8, wherein the composition contains 0.1 to 1.2 weight percent of manganese.

11. Use of a steel sheet according to any one of claims 8 to 10 for the manufacture of parts for an electric vehicle or an electrical machine.

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