Method for manufacturing non-oriented electrical steel

Abstract

The present invention relates to a method for producing a non-oriented electrical steel sheet, said method comprising a step of warm-rolling said hot-rolled steel sheet, said warm-rolling comprising five to eight rolling passes, said warm-rolling comprising a peak temperature rolling pass, the peak temperature rolling pass is a fourth or fifth rolling pass having a steel sheet inlet temperature of 210 DEG C to 250 DEG C, and is a warm rolling pass having a maximum inlet temperature,-a rolling pass preceding the peak rolling temperature rolling pass is performed at a steel sheet inlet temperature of 170 DEG C to 230 DEG C, -the steel sheet inlet temperature of the warm rolling pass after said peak temperature rolling is 10 DEG C to 30 DEG C lower than the previous rolling pass.

Description

TECHNICAL FIELD

[0001] The present invention relates to a manufacturing method of non-oriented electrical steel. In particular, the present invention relates to a method allowing the manufacturing of a fully recrystallized ferritic non-oriented electrical steel achieving good magnetic properties, in particular in terms of polarization. BACKGROUND

[0002] US patent application US20150213928 A1 discloses a process to manufacture a high strength electrical steel sheet having excellent magnetic properties, such as low iron loss.

[0003] The steel composition comprises in weight percent a high content of silicon of 3.5 to 4.5, a C content of 0.005% or less, a Mn content of 0.01% to 0.10%, an Al content of 0.005% or less, a Ca content of 0.0010% to 0.0050%, a S content of 0.0030% or less, and a N content of 0.0030% or less, the remainder being Fe and incidental impurities. The sheet thickness is 0.40 mm or less and the unrecrystallized deformed microstructure is 10% to 70%.

[0004] The manufacturing process comprises a hot band annealing between 900°C and 1000°C and a warm rolling at several hundreds of °C to reduce the sheet breaking.

[0005] The inventors use the unrecrystallized and reverted microstructure as a mean to strengthen the sheet without using precipitates such as carbonitrides. In this patent application, the composition is reduced as much as possible except for Si to reduce the variations of the resulting microstructure and tensile strength.

[0006] However, the method disclosed in this patent is not able to exhibit the effect of the second rolling, such as warm rolling, on the magnetic properties. SUMMARY

[0007] The object of the present invention is to improve the polarization of non-oriented electrical steel. This is performed by the claimed warm rolling improving the texture.

[0008] The present invention relates to a method of producing a non-oriented electrical steel sheet, said method comprising the steps of:

[0009] - providing a steel composition comprising the following elements, expressed in weight percent,

[0010] 0.0001% ≤ Carbon ≤ 0.008%

[0011] 0.1% ≤ Manganese ≤ 2.0%

[0012] 2.6% ≤ Silicon ≤ 6.5%

[0013] 0.1% ≤ Aluminum ≤ 1.2%

[0014] 0% < phosphorus < 0.15%

[0015] 0% < sulfur < 0.006%

[0016] 0% < nitrogen < 0.09%

[0017] with 3.5% < Si + Al + Mn < 9.5%

[0018] and can comprise one or more of the following optional elements

[0019] 0% < niobium < 0.1%

[0020] 0% < titanium < 0.1%

[0021] 0% < vanadium < 0.1%

[0022] 0% < chromium < 1%

[0023] 0% < molybdenum < 0.5%

[0024] 0% < tungsten < 0.1%

[0025] 0% < cobalt < 1%

[0026] 0% < arsenic < 0.05%

[0027] 0.001% < calcium < 0.01%

[0028] 0% < copper < 1%

[0029] 0% < nickel < 1%

[0030] 0% < boron < 0.05%

[0031] 0% < lead < 0.2%

[0032] 0% < tin < 0.2%

[0033] 0% < antimony < 0.2%

[0034] the remainder consisting of iron and unavoidable impurities resulting from the processing,

[0035] - reheating the semi-finished product to a temperature of between 1050°C and 1250°C,

[0036] - hot rolling the semi-finished product to obtain a hot-rolled steel sheet, with the hot rolling final rolling temperature being between 750°C and 950°C,

[0037] - The hot-rolled steel sheet is cooled immediately after hot rolling.

[0038] - The hot-rolled steel sheet is then cooled from hot rolling completion to a coiling temperature range of 450°C to 750°C at a cooling rate of at least 10°C / second.

[0039] - Subsequently, the hot-rolled steel sheet is coiled within a coiling temperature range of 450°C to 750°C.

[0040] - Optionally, a scale removal process is performed on the hot-rolled steel sheet.

[0041] - Optionally, hot-rolled steel sheets may be subjected to tropical annealing at 650°C to 1100°C for 10 seconds to 96 hours.

[0042] - Optionally, a scale removal process is performed on the hot-rolled steel sheet.

[0043] - The hot-rolled steel sheet is subjected to warm rolling, wherein the warm rolling comprises five to eight rolling passes, wherein

[0044] - Warm rolling includes peak temperature rolling passes, which are the fourth or fifth rolling passes with a steel plate inlet temperature of 210°C to 250°C, and are the warm rolling passes with the maximum inlet temperature.

[0045] - The rolling passes preceding the peak temperature rolling pass are performed at a steel plate inlet temperature of 170°C to 230°C.

[0046] - The inlet temperature of the steel sheet in the warm rolling pass after the peak temperature rolling is 10°C to 30°C lower than that of the previous rolling pass.

[0047] - The warm-rolled steel sheet is then annealed, wherein the heating for annealing ranges from room temperature to an annealing temperature range of 800°C to 1100°C. 均热 The heating rate HR1 is at least 1°C / second.

[0048] - Then perform annealing at the annealing temperature for 10 to 5000 seconds to ensure 100% recrystallization.

[0049] - The warm-rolled steel sheet is then cooled to obtain a non-oriented electrical steel sheet, the cooling starting from the annealing temperature to a temperature T1 of 300°C to room temperature, and the cooling rate CR1 is 1°C / second to 150°C / second.

[0050] Chemical composition

[0051] The chemical composition of non-oriented electrical steel includes the following elements:

[0052] The carbon content in the steel of this invention is 0.0001 to 0.008 by weight percentage.

[0053] Carbon is a precipitate-forming element that is detrimental to the magnetic properties of the steel of the present invention. Since carbon promotes magnetic aging, the preferred carbon content according to the present invention is 0.0001 to 0.006% by weight, and more preferably 0.0001 to 0.005% by weight.

[0054] The manganese content in the steel of this invention is 0.1 to 2% by weight.

[0055] Manganese provides solid solution strengthening and reduces iron loss by increasing resistivity.

[0056] Preferably, the manganese content in the steel of the present invention is 0.1 to 1.2% by weight. Even more preferably, the manganese content in the steel of the present invention is 0.1 to 0.5% by weight.

[0057] Alternatively, the manganese content in the steel of the present invention is 0.5 to 2.0% by weight.

[0058] The silicon content in the steel of this invention is 2.6 to 6.5% by weight.

[0059] Silicon is an element that helps improve strength through solid solution strengthening and is a key element in reducing eddy current losses and iron losses by increasing the resistivity of steel. The aforementioned effects require a minimum silicon content of at least 2.6 wt%. However, when the silicon content exceeds 3.5 wt%, rolling becomes difficult and the magnetic flux density of the steel decreases significantly. The preferred limit for the presence of silicon is 2.6 to 5.0 wt%, and more preferably 2.8 to 4.0 wt%.

[0060] The aluminum content in the steel of this invention is 0.1 to 1.2% by weight.

[0061] Aluminum increases the resistivity of materials and can effectively reduce iron loss in steel. When the aluminum content is greater than 1.2% by weight, the magnetic induction intensity of the steel of the present invention will be significantly reduced. The preferred limit for the aluminum content is 0.7 to 1.2% by weight, and more preferably 0.8 to 1.1% by weight.

[0062] Alternatively, the preferred limit for aluminum content is 0.4 to 0.7% by weight.

[0063] The non-oriented electrical steel sheet according to the invention is forcibly incorporating silicon, manganese, and aluminum, such that the total content is 3.5 to 9.5% by weight. When the total content of Si, Mn, and Al is less than 3.5% by weight, it is impossible to achieve the mechanical and magnetic properties in both the transverse and rolling directions. However, when the total content of Si, Mn, and Al exceeds 9.5% by weight, the steel hardens and rolling becomes difficult.

[0064] Even more preferably, the total content of Si, Mn and Al is 3.5 to 5.5% by weight.

[0065] The phosphorus content in the steel of this invention is 0 to 0.15% by weight.

[0066] Phosphorus reduces hot and cold ductility, particularly due to its tendency to segregate at grain boundaries or co-segregate with manganese. For these reasons, the phosphorus content is limited to 0.15% by weight, and preferably less than 0.09% by weight.

[0067] Sulfur is not an essential element but may be present in steel as an impurity, and from the perspective of this invention, the sulfur content is preferably as low as possible, but from the perspective of manufacturing cost, it is 0.006% by weight or less. Furthermore, if a higher level of sulfur is present in the steel, it can combine to form sulfides that are detrimental to the magnetic properties of this invention.

[0068] Nitrogen is not an essential element but may be present in steel as an impurity. Nitrogen is limited to 0.09% to minimize the precipitation of aluminum nitrides, which are detrimental to the magnetic properties of steel during solidification.

[0069] Niobium is an optional element, and the niobium content in the steel of the present invention is 0 to 0.1% by weight.

[0070] Niobium is suitable for forming carbonitrides to improve the strength of the steel of the present invention through precipitation hardening. Niobium will also affect the size of the microstructure composition by precipitating as carbonitrides. However, due to the saturation effect, a niobium content above 0.1% by weight is not economically interesting.

[0071] Titanium is an optional element in the composition of the steel of the present invention. The titanium content in the steel of the present invention is 0 to 0.1% by weight.

[0072] Titanium forms titanium nitrides during the solidification of the cast product. The amount of titanium is therefore limited to 0.1% by weight to limit the formation of titanium nitrides that are detrimental to the magnetic properties of the steel of the present invention.

[0073] Vanadium is an optional element, and the vanadium content in the steel of the present invention is 0 to 0.1% by weight.

[0074] Vanadium is effective in enhancing the strength of steel by forming carbides or carbonitrides, and from an economic point of view, the upper limit is 0.1% by weight.

[0075] Chromium is an optional element in the composition of the steel of the present invention. The chromium content in the steel of the present invention is 0 to 1% by weight.

[0076] Chromium provides strength to steel through solid solution strengthening, but when used at a weight percentage higher than 1%, it impairs the surface finish of the steel.

[0077] Molybdenum is an optional element in the composition of the steel of the present invention. The molybdenum content in the steel of the present invention is 0 to 0.5% by weight.

[0078] Molybdenum has a significant effect on coarsening carbides and thus reducing iron loss. Without theoretical constraints, the effect of improving iron loss saturates when molybdenum exceeds 0.5% by weight.

[0079] Tungsten is an optional element in the composition of the steel of the present invention. The tungsten content in the steel of the present invention is 0 to 0.1% by weight.

[0080] Clearly, like Mo, tungsten has the effect of coarsening carbides and reducing iron loss. Without theoretical constraints, when the addition amount is less than 0.001 wt%, the above effects cannot be fully obtained, while when the addition amount exceeds 0.1 wt%, the effect of improving iron loss saturates.

[0081] Cobalt is an optional element in the composition of the steel of the present invention. The cobalt content in the steel of the present invention is 0 to 1% by weight.

[0082] Without theoretical constraints, cobalt is an element that increases the magnetic moment of Fe alloys and also increases magnetic flux density and reduces iron loss. However, without theoretical constraints, when the addition amount is less than 0.01% by weight, these effects cannot be fully achieved, while when the addition amount exceeds 1% by weight, the raw material cost increases significantly.

[0083] Arsenic is an optional element in the composition of the steel of the present invention. The arsenic content in the steel of the present invention is 0 to 0.05% by weight.

[0084] Without theoretical constraints, arsenic is a grain boundary segregating element and has the effect of improving texture and thus reducing iron loss. This effect is obtained by adding at least 0.001 weight percent. Without theoretical constraints, arsenic is an element that causes grain boundary embrittlement, and this adverse effect becomes particularly significant when arsenic is added at a weight percentage greater than 0.05%. Therefore, As is preferably added in the range of 0.001 to 0.05 weight percent.

[0085] Nickel is an optional element in the composition of the steel of the present invention. The nickel content in the steel of the present invention is 0 to 1% by weight.

[0086] Nickel increases the strength of the steel of the present invention and improves its strength and elongation. However, when the nickel content is higher than 1% by weight, nickel leads to a deterioration in ductility.

[0087] Copper is an optional element in the composition of the steel of the present invention. The copper content in the steel of the present invention is 0 to 1% by weight.

[0088] Copper improves the strength and elongation of the steel of this invention. However, when the copper content is higher than 1% by weight, it can significantly degrade the surface features and magnetic properties by forming precipitates.

[0089] Boron is an optional element in the composition of the steel of the present invention. The boron content in the steel of the present invention is 0 to 0.05% by weight.

[0090] When added in an amount of at least 0.0001% by weight, boron forms boron nitrides and imparts additional strength to the steel of the present invention.

[0091] Calcium is an optional element in the composition of the steel of the present invention. The calcium content in the steel of the present invention is 0 to 0.01% by weight, and preferably 0.001 to 0.01% by weight.

[0092] Clearly, calcium contributes to steel refining by binding harmful sulfur content in a spherical form, thereby delaying the harmful effects of sulfur.

[0093] Other elements such as Sn, Pb, or Sb may be added, alone or in combination, in the following proportions: Sn ≤ 0.2 wt%, Pb ≤ 0.2 wt%, and Sb ≤ 0.2 wt%. Up to the indicated maximum content level, these elements allow for grain refinement during solidification. The remainder of the steel composition consists of iron and unavoidable impurities resulting from processing.

[0094] The method according to the invention includes providing a steel semi-finished casting having the chemical composition of steel according to the invention.

[0095] For example, it can be cast into steel ingots, or continuously cast in the form of thin slabs or thin strips, i.e., the thickness ranges from tens of millimeters (for thin strips) to about 220 mm (for slabs).

[0096] The casting is then reheated to a temperature of 1050°C to 1250°C.

[0097] Below 1050°C, the hot rolling temperature becomes too low, making rolling difficult and the forces on the mill too high. Above 1250°C, the steel may become very soft and may exhibit some sagging, thus becoming difficult to handle.

[0098] The reheated slab is then hot-rolled to obtain hot-rolled steel sheet. The final hot rolling temperature is between 750°C and 950°C.

[0099] Below 750°C, recrystallization is limited and the microstructure is highly deformed. Above 950°C, this means higher reheating temperatures and therefore more impurities in the solid solution, potentially leading to precipitation and deterioration of magnetic properties.

[0100] Hot-rolled steel sheet then at at least 10°C for 1 second. -1 The cooling rate is such that the winding temperature is between 450°C and 750°C. Preferably, the cooling rate is less than or equal to 200°C / second. -1 .

[0101] Below 450°C, such a coiling temperature will not allow sufficient recovery to occur, which is necessary for the magnetic properties. Above 750°C, a thick internal oxide layer will form, making subsequent processing steps such as warm rolling and / or pickling difficult.

[0102] Hot-rolled steel sheets may optionally undergo a scale removal step in order to at least partially remove the scale formed during hot rolling.

[0103] The hot-rolled steel sheet is then optionally subjected to tropical annealing. Tropical annealing is performed at a temperature of 650°C to 1100°C for at least 10 seconds and not more than 96 hours. Preferably, tropical annealing is performed at a temperature of 700°C to 1070°C, and more preferably 720°C to 1050°C.

[0104] Optionally, the oxide scale removal step of such hot-rolled or hot-annealed steel sheet can be performed, for example, by pickling such steel sheet.

[0105] Warm rolling

[0106] The hot-rolled or hot-rolled annealed steel sheet is then subjected to warm rolling to obtain a warm-rolled steel sheet, preferably with a thickness reduction of 35% to 90%.

[0107] Warm rolling includes five to eight rolling passes, among which

[0108] - Warm rolling includes peak temperature rolling, which is the fourth or fifth rolling pass and has a steel plate inlet temperature of 210°C to 250°C, wherein

[0109] - The rolling passes prior to the peak rolling temperature are performed at a steel plate inlet temperature of 170°C to 230°C.

[0110] - The inlet temperature of the steel sheet in the warm rolling pass after the peak temperature rolling is 10°C to 30°C lower than that of the previous rolling pass.

[0111] Preferably, the peak rolling temperature is the fourth rolling pass and has an inlet temperature of 200°C to 220°C.

[0112] Preferably, the peak rolling temperature is the fifth rolling pass and has an inlet temperature of 215°C to 240°C.

[0113] Annealing

[0114] The warm-rolled steel sheet is then heated, starting from room temperature, with the heating time being at least 1°C per second. -1 The heating rate is increased to an annealing temperature T of 800°C to 1100°C. 均热 The warm-rolled steel sheet is held at the annealing temperature for 10 to 5000 seconds to ensure 100% recrystallization.

[0115] Preferably, the heating rate is at least 2°C / second. -1 And even more preferably at least 5°C per second. -1 .

[0116] Preferably, the annealing temperature T 均热 The temperature is 1000°C to 1100°C, and even more preferably 1020°C to 1100°C.

[0117] Preferably, the warm-rolled steel sheet is held at the annealing temperature for at least 20 seconds. Even more preferably, the warm-rolled steel sheet is held at the annealing temperature for at least 30 seconds.

[0118] The warm-rolled steel sheet is then cooled, with the cooling process starting from T. 均热 Initially, the warm-rolled steel sheet is cooled to a temperature T1 ranging from 20°C to 300°C at a cooling rate of 1°C / second to 150°C / second. In a preferred embodiment, the cooling rate CR1 is 3°C / second to 120°C / second. The preferred T1 temperature is 20°C to 200°C.

[0119] Cooling of warm-rolled steel sheets can be performed in multiple cooling steps, which can have different cooling rates.

[0120] Then, the warm-rolled steel sheet is cooled to room temperature to obtain non-oriented electrical steel sheet.

[0121] The non-oriented electrical steel sheet of the present invention may optionally be coated with an insulating layer, an organic coating or an inorganic coating or a combination thereof to improve insulation.

[0122] The present invention also relates to non-oriented electrical steel sheets having a composition comprising the following elements: expressed as a percentage by weight.

[0123] 0.0001% ≤ Carbon ≤ 0.008%

[0124] 0.1% ≤ Manganese ≤ 2.0%

[0125] 2.8% ≤ Silicon ≤ 6.5%

[0126] 0.1% ≤ Aluminum ≤ 1.2%

[0127] 0% ≤ Phosphorus ≤ 0.15%

[0128] 0% ≤ Sulfur ≤ 0.006%

[0129] 0% ≤ Nitrogen ≤ 0.09%

[0130] Of which 3.5% ≤ Si+Al+Mn ≤ 9.5%

[0131] It may contain one or more of the following optional elements.

[0132] 0% ≤ Niobium ≤ 0.1%

[0133] 0% ≤ Titanium ≤ 0.1%

[0134] 0% ≤ Vanadium ≤ 0.1%

[0135] 0% ≤ Chromium ≤ 1%

[0136] 0% ≤ Molybdenum ≤ 0.5%

[0137] 0% ≤ Tungsten ≤ 0.1%

[0138] 0% ≤ Cobalt ≤ 1%

[0139] 0% ≤ Arsenic ≤ 0.05%

[0140] 0% ≤ Calcium ≤ 0.01%

[0141] 0% ≤ Copper ≤ 1%

[0142] 0% ≤ Nickel ≤ 1%

[0143] 0% ≤ Boron ≤ 0.05%

[0144] 0% ≤ Lead ≤ 0.2%

[0145] 0% ≤ Tin ≤ 0.2%

[0146] 0% ≤ Antimony ≤ 0.2%

[0147] The remaining portion consists of iron and unavoidable impurities caused by processing. The microstructure of the steel plate is composed of ferrite and contains 100% recrystallized microstructure by area fraction, wherein the average grain size of the recrystallized microstructure is 15 micrometers to 250 micrometers and satisfies the following equation: ,in

[0148] - J50 uses magnetic polarization measured in Tesla.

[0149] - T R1 It is the temperature at the inlet of the first rolling pass.

[0150] - T R2 It is the temperature at the inlet of the second rolling pass.

[0151] - T R3 It is the temperature at the entrance of the third rolling pass.

[0152] - T f It is a texture factor.

[0153] - d is the average grain size in µm.

[0154] - ρ is The resistivity is calculated.

[0155] Area fraction and grain size were measured using the linear intercept method according to ASTM E112 standard.

[0156] Texture factor is defined as cubic fibers and The ratio of gamma fibers. The ratio of cubic fibers to gamma fibers can be measured using XRD. For example, a diffractometer operates at 35 kV and 45 mA.

[0157] The average grain size was measured using the linear intercept method according to ASTM E112 (2013) standard.

[0158] Resistivity is measured according to ASTM A712-14 standard.

[0159] Preferably, the composition comprises 2.8 to 4.0 weight percent silicon.

[0160] Preferably, the composition contains 0.1 to 1.2 weight percent of manganese. Alternatively, the composition may contain 0.5 to 2.0 weight percent of manganese.

[0161] The steel of the present invention has a microstructure composed of ferrite. The microstructure of the non-oriented electrical steel does not contain microstructure components such as martensite, bainite, pearlite, and cementite.

[0162] The steel of the present invention has a recrystallized microstructure region with an area fraction of 100%.

[0163] The steel of the present invention has grains with an average grain size of 15 micrometers to 250 micrometers. The average grain size is measured by the linear intercept method according to ASTM E112 (2013) standard.

[0164] Preferably, the average grain size is between 15 micrometers and 35 micrometers. Obviously, this grain size range is preferred for the field of high-speed rotors.

[0165] Preferably, the average grain size is between 35 micrometers and 80 micrometers. Obviously, this grain size range is preferred for the stators and high-speed rotors of high-frequency motors.

[0166] Preferably, the average grain size is between 80 micrometers and 120 micrometers. Obviously, this grain size range is preferred for applications involving stators that utilize torque.

[0167] Preferably, the average grain size is between 120 micrometers and 250 micrometers. Obviously, this grain size range is preferred for the field of industrial generators and traction or propulsion motors.

[0168] Preferably, the following equation is satisfied: Even more preferably, the following equation is satisfied: .

[0169] The present invention also relates to the use of the steel plate as described above or the steel plate produced as described above for manufacturing components of electric vehicles or motors.

[0170] The present invention also relates to vehicles or motors that include the components obtained as described above. Detailed Implementation

[0171] Examples

[0172] The tests, embodiments, illustrative examples, and tables presented herein are non-limiting in nature and must be considered for illustrative purposes only, and will present advantageous features of the invention.

[0173] Steel plates made from steels with different compositions are summarized in Table 1.

[0174] The steel plates are produced according to the process parameters listed in Tables 2 and 3.

[0175] Table 2 summarizes the process parameters for reheating, hot rolling, coiling, and hot annealing.

[0176] Table 3 summarizes the process parameters for the second rolling process, i.e., cold rolling or warm rolling, and the final annealing.

[0177] Table 4 illustrates the results of tests conducted on both the invention steel and the reference steel.

[0178] The invented steel and the reference steel should be compared in pairs.

[0179] For example, references to 1 and 4 allow for the assessment of the effects of the claimed hot rolling on texture and magnetic polarization. Indeed, other process parameters are the same, namely hot rolling, coiling, hot-roll annealing, and final annealing.

[0180] The steel according to the invention, “Invention 4”, has a better texture factor than “Reference 1”, which allows for better magnetic polarization than “Reference 1”.

[0181] The same reasoning and conclusions can be made using the following pairs: “Ref. 2” and “Invention 5”, “Ref. 3” and “Invention 6”, “Ref. 7” and “Invention 10”, “Ref. 8” and “Invention 11”, “Ref. 9” and “Invention 12”.

[0182] Therefore, it is evident that this process allows for improvements in the polarization and texture of non-oriented electrical steel.

[0183]

[0184] Table 1: Composition of steel by weight percentage

[0185]

[0186] Table 2: Process parameters for reheating, hot rolling, coiling, and HBA steps

[0187]

[0188] Table 3: Process parameters for warm rolling and rolling according to existing technology

[0189]

[0190] Table 4: Microstructure and Magnetic Properties

Claims

1. A method for producing non-oriented electrical steel sheets, the method comprising the following steps: - Provide a steel composition comprising the following elements, expressed as a weight percentage. 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% Of which 3.5% ≤ Si+Al+Mn ≤ 9.5% And can include one or more 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% The remaining portion consists of iron and unavoidable impurities caused by processing. - The semi-finished product is then reheated to a temperature of 1050°C to 1250°C. - The semi-finished product is hot-rolled to obtain a hot-rolled steel sheet, wherein the final hot-rolling temperature is between 750°C and 950°C. - The hot-rolled steel sheet is cooled immediately after the hot rolling is completed. - The hot-rolled steel sheet is then cooled from hot rolling completion to a coiling temperature range of 450°C to 750°C at a cooling rate of at least 10°C / second. - The hot-rolled steel sheet is then wound within the winding temperature range of 450°C to 750°C. - Optionally, a scale removal process is performed on the hot-rolled steel sheet. - Optionally, hot-rolled steel sheets may be subjected to tropical annealing at 650°C to 1100°C for 10 seconds to 96 hours. - Optionally, a scale removal process is performed on the hot-rolled steel sheet. - The hot-rolled steel sheet is subjected to warm rolling, wherein the warm rolling comprises five to eight rolling passes, wherein - The warm rolling includes a peak temperature rolling pass, which is the fourth or fifth rolling pass with an inlet temperature of 210°C to 250°C for the steel sheet, and is the warm rolling pass with the maximum inlet temperature. - The rolling passes preceding the peak temperature rolling pass are performed at an inlet temperature of 170°C to 230°C for the steel plate. - The inlet temperature of the steel sheet in the warm rolling pass after the peak temperature rolling is 10°C to 30°C lower than that of the previous rolling pass. - The warm-rolled steel sheet is then annealed, wherein the heating for annealing ranges from room temperature to an annealing temperature range of 800°C to 1100°C. 均热 The heating rate HR1 is at least 1°C / second. - Then perform annealing at the annealing temperature for 10 to 5000 seconds to ensure 100% recrystallization. - The warm-rolled steel sheet is then cooled to obtain a non-oriented electrical steel sheet, the cooling starting from the annealing temperature to a temperature T1 of 300°C to room temperature, the cooling rate CR1 being 1°C / second to 150°C / second.

2. The method according to claim 1, wherein the peak rolling temperature is the fourth rolling pass and has an inlet temperature of 200°C to 220°C.

3. The method according to claim 1, wherein the peak rolling temperature is the fifth rolling pass and has an inlet temperature of 215°C to 240°C.

4. The method according to any one of claims 1 to 3, wherein the annealing temperature range T 均热 The temperature ranges from 1000℃ to 1100℃.

5. The method according to claim 4, wherein the annealing temperature range T 均热 The temperature ranges from 1020℃ to 1100℃.

6. The method according to claim 5, wherein the annealing temperature range T 均热 The temperature ranges from 1050℃ to 1100℃.

7. A non-oriented electrical steel sheet having a composition comprising the following elements: expressed as a percentage by weight, 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% Of which 3.5% ≤ Si+Al+Mn ≤ 9.5% And can include one or more 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% The remaining portion consists of iron and unavoidable impurities caused by processing. The microstructure of the steel plate is composed of ferrite and contains 100% recrystallized microstructure by area fraction, wherein the average grain size of the recrystallized microstructure is 15 micrometers to 250 micrometers and satisfies the following equation: ,in - J50 is a magnetic polarization measured in Tesla. - T R1 It is the temperature at the inlet of the first rolling pass. - T R2 It is the temperature at the inlet of the second rolling pass. - T R3 It is the temperature at the entrance of the third rolling pass. - T f It is a texture factor. - d is the average grain size in µm, and - ρ is The resistivity is calculated.

8. The non-oriented electrical steel sheet of claim 7, wherein the composition comprises 2.8 to 4.0 weight percent silicon.

9. The non-oriented electrical steel sheet according to claim 7 or 8, wherein the composition comprises 0.1 to 1.2 weight percent manganese.

10. The non-oriented electrical steel sheet according to claim 7 or 8, wherein the composition comprises 0.5 to 2.0 weight percent manganese.

11. Use of the steel sheet according to any one of claims 7 to 10 or the steel sheet produced by the method according to claims 1 to 6 for manufacturing components of electric vehicles or motors.

12. A vehicle or motor comprising the component obtained according to claim 11.

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