CHAPA DE AÇO ELÉTRICO NÃO ORIENTADO E MÉTODO DE PRODUÇÃO DE UMA CHAPA DE AÇO ELÉTRICO NÃO ORIENTADO

Abstract

The invention deals with a non-oriented electrical steel sheet having a composition comprising of the following elements, expressed in percentage by weight: 0.0001% ≤ Carbon ≤ 0.005 % 0.2% ≤ Manganese ≤ 0.3% 3.1% ≤ Silicon ≤ 3.6% 0.6% ≤ Aluminum ≤ 1 % Phosphorus ≤ 0.15 % Sulfur ≤ 0.006% Nitrogen ≤ 0.09% and can contain 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% 0.001% ≤ 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 remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet being made of ferrite and comprising in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of 18 recrystallized microstructure is from 20 microns to 110microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, from 30% to 35% when calculated in accordance of Bertotti method.

Description

1 / 14 “NON-ORIENTED ELECTRICAL STEEL SHEET AND METHOD OF PRODUCING A NON-ORIENTED ELECTRICAL STEEL SHEET” Field of invention

[001] The present invention relates to a non-oriented electrical steel sheet and its manufacturing method. Specifically, the present invention relates to a non-oriented electrical steel sheet and its manufacturing method that exhibits low iron losses, especially low eddy current losses, as well as good mechanical properties. Background of the Invention

[002] Therefore, intense research and development efforts have been put into achieving higher performance properties for non-oriented electrical steel sheets to be used as an iron core material for electrical machines due to a worldwide increase in the pursuit of energy efficiency from electrical appliances. Recently, in particular, as a motor to be used for an electric vehicle or similar, there has been a high demand for a small, high-power motor. Such an electric vehicle motor is designed to make high-speed rotation possible, thus achieving high torque with the lowest possible losses. This requires lightweight and highly efficient non-oriented electrical steels that have low losses as their main property. Finding the balance between losses, permeability, polarization, thermal conductivity, tensile strength, and yield strength is vital for non-oriented electrical steels.

[003] The lower the iron losses in an electric machine, the greater its efficiency. Therefore, to reduce the amount of iron losses in an electric machine, electric machine manufacturers have several options, the main ones being to reduce hysteresis losses or eddy current losses to improve the efficiency of their electric machines. Advances are often achieved by combining both approaches. This Petition 870250098838, dated 10 / 29 / 2025, page 10 / 32 2 / 14 The invention refers to the second option, namely, the reduction of eddy current losses in an electrical machine. There are two tracking alternatives to reduce eddy current losses.

[004] The first approach consists of reducing the thickness of the steel sheets used in electric machines, so that the thickness of the steel sheet is less than 0.35 mm or even less. Unfortunately, this solution has its limitations due to the reduction in the stacking factor, which decreases the torque achievable for a given machine height, in addition to a prohibitive reduction in the rigidity of certain automotive parts and the emergence of acoustic problems that create uncomfortable conditions for the passenger.

[005] The second approach consists of optimizing the elemental composition of the steel sheet, such as increasing the amount of alloying elements to restrict eddy current losses. Among these alloying elements, aluminum and manganese have attractive mechanical and magnetic properties, enabling a significant reduction in eddy current losses. However, the addition of alloying elements can only be done up to a certain limit, because after a certain percentage, the presence of alloying elements will impact hysteresis losses and magnetic polarization.

[006] Previous research and development in the field of high-strength non-oriented electrical steel has resulted in several methods for producing high-strength non-oriented electrical steel, some of which are enumerated here for conclusive appreciation of the present invention.

[007] US patent 2021 / 371948 refers to an electrically non-oriented steel plate with an average magnetostriction λρ - pa 400 Hz and 1.0 T of no more than 4.5 x 10⁻⁶, and a recrystallized grain area ratio in a section in the rolling direction of the steel plate of 40 to 95% and an average grain size of 10 to 40 microns obtained by subjecting a steel plate Petition 870250098838, dated 10 / 29 / 2025, page 11 / 32 3 / 14 containing, by mass %, C: not more than 0.005%, Si: 2.8 to 6.5%, Mn: 0.05 to 2.0%, Al: not more than 3.0%, P: not more than 0.20%, S: not more than 0.005%, N: not more than 0.005%, Ti: not more than 0.003%, V: not more than 0.005% and Nb: not more than 0.005% and satisfying Si - 2A1 - Mn>0 for hot rolling, hot strip annealing, cold rolling and finish annealing under suitable cold rolling and finish annealing conditions, and an engine core is manufactured from such steel sheet. US patent 2021 / 371948 does not demonstrate total elongation and eddy current loss. Brief Description of the Invention

[008] The objective of the present invention is to solve these problems by means of manufacturing non-oriented electrical steel sheets which simultaneously exhibit a percentage of eddy current loss in the total iron loss of 30% to 35% and, preferably, of 30% to 35% when calculated according to the Bertotti method.

[009] In preferred embodiments, the following additional properties can also be achieved, alone or in combination: - an ultimate tensile strength of 500 MPa or more, in both the transverse and rolling directions, and preferably more than 535 MPa, in both the transverse and rolling directions; - a yield strength of 380 MPa or more in both the transverse and rolling directions, and preferably 410 MPa or more in both the transverse and rolling directions; - a total elongation of 17% or more in both the transverse and rolling directions, and preferably greater than or equal to 18% in both the transverse and rolling directions; - a magnetic polarization of 5000 A / m (J50) of 1.66T Petition 870250098838, dated 10 / 29 / 2025, page 12 / 32 4 / 14 1.70T and, preferably, a magnetic polarization at 5000 A / m (J50) from 1.66T to 1.69T and, more preferably, a magnetic polarization at 5000 A / m (J50) from 1.665T to 1.685T; - a total loss of 12 to 14 W / kg when measured at 1 T and 400 Hz and preferably 12 to 13.5 W / kg when measured at 1 T and 400 Hz.

[010] Preferably, this steel may also be well suited for rolling, with good drilling and coating capabilities.

[011] Preferably, a hardness greater than or equal to 185 HV and, preferably, a hardness greater than or equal to 195 HV.

[012] Another objective of the present invention is also to provide a method for manufacturing these sheets that is compatible with conventional industrial applications and at the same time robust to changes in manufacturing parameters. Detailed Description of the Invention

[013] The above objective and other advantages of the present invention will become more apparent when describing in detail the preferred embodiment of the present invention.

[014] The chemical composition of non-oriented electrical steel comprises the following elements in weight percent.

[015] The carbon content in the steel of the present invention varies from 0.0001% to 0.005%. Carbon is a precipitate-forming element and is therefore detrimental to the magnetic properties of steel. Therefore, the carbon content in the present steel varies from 0.0001% to 0.007%. As carbon promotes magnetic aging, the preferred carbon content according to the present invention varies from 0.001% to 0.004% and, more preferably, from 0.001% to 0.003%.

[016] The manganese content of the steel of the present invention varies from 0.2% to 0.3%. Manganese provides solid solution strength and reduces the Petition 870250098838, dated 10 / 29 / 2025, page 13 / 32 5 / 14 loss of iron, increasing specific strength. When the addition of manganese exceeds 0.3%, the magnetic flux density can be considerably reduced, impairing the recrystallization of the steel during annealing. The preferred limit for the presence of manganese is 0.2% to 0.27%, and more preferably 0.2% to 0.25%.

[017] The silicon content of the steel of the present invention ranges from 3.1% to 3.6%. Silicon is an element that contributes to increased strength through solid solution strengthening and is a key element in reducing eddy current losses in iron, increasing the specific strength of the steel. The aforementioned effects require a minimum silicon content of at least 3.1%. However, when the silicon content exceeds 3.6%, rolling becomes difficult and the magnetic induction of the steel is significantly reduced. The preferred limit for the presence of silicon is 3.1% to 3.5%, and more preferably 3.2% to 3.4%.

[018] The aluminum content varies from 0.6% to 1%. Aluminum increases the electrical resistivity of the material and can effectively reduce iron loss from the steel. When the aluminum content is present in more than 1%, the magnetic induction of the steel will be significantly reduced, which is also detrimental to the cold rolling capacity of the steel of the present invention. The preferred limit for the presence of aluminum is from 0.7% to 0.9%, and more preferably from 0.8% to 0.9%.

[019] Sulfur is not an essential element, but it can be present as an impurity in steel and, from the point of view of the present invention, the sulfur content is preferably as low as possible, but 0.006% or less from the point of view of manufacturing cost. Furthermore, if there is a higher amount of sulfur in the steel, it combines to form sulfides, which are detrimental to the magnetic properties of the present invention.

[020] The phosphorus constituent of the steel of the present invention varies from Petition 870250098838, dated 10 / 29 / 2025, page 14 / 32 6 / 14 0% to 0.15%. Phosphorus reduces hot and cold ductility, particularly due to its tendency to segregate at grain boundaries or co-segregate with manganese. For these reasons, its content is limited to 0.15% and preferably from 0.09% to 0.13%.

[021] Nitrogen is limited to 0.09% to minimize the precipitation of aluminum nitrides during solidification, which are detrimental to the magnetic properties of steel.

[022] Titanium is an optional element and, when added to the steel of the present invention, varies from 0% to 0.1%. It forms titanium nitrides that appear during the solidification of the molten product. The amount of titanium is limited to 0.1% to avoid the formation of titanium nitrides, which are detrimental to the magnetic properties of the steel of the present invention. If the titanium content is below 0.001%, it does not affect the steel of the present invention.

[023] Niobium is present in the steel of the present invention from 0% to 0.1% and is suitable for the formation of carbonitrides, to increase the strength of the steel of the present invention by precipitation hardening. Niobium also impacts the size of microstructural components by its precipitation as carbonitrides. However, niobium contents above 0.1% are not economically interesting as a saturation effect.

[024] Vanadium is present in the steel of the present invention from 0% to 0.1% and is effective in increasing the strength of the steel by the formation of carbides or carbonitrides, the upper limit being 0.1% from an economic point of view.

[025] Chromium is an optional element for the steel of the present invention, ranging from 0% to 1%. Chromium imparts strength to the steel by means of solid solution strengthening, but when used in concentrations above 1%, it impairs the magnetic properties of the steel. In a preferred embodiment, the chromium content is at least 0.01%. Petition 870250098838, dated 10 / 29 / 2025, page 15 / 32 7 / 14

[026] Molybdenum is an optional element that constitutes 0% to 0.5% of the steel of the present invention. Mo has the effect of thickening the carbide, thus reducing iron loss. When it exceeds 0.5%, the iron loss improvement effect is saturated.

[027] Tungsten is an optional element that constitutes 0% to 0.1% of the steel of the present invention. Tungsten, like Mo, has the effect of thickening the carbide and reducing iron loss. However, when the amount added is less than 0.001% by mass, the above effect cannot be sufficiently obtained, while when it exceeds 0.1% by weight, the effect of improving iron loss is saturated.

[028] Cobalt is an optional element that constitutes 0% to 1% of the steel of the present invention. Cobalt is an element that increases the magnetic moment of the Fe alloy and has the effect of increasing the magnetic flux density and reducing iron loss. However, when the amount added is less than 0.01% by weight, the above effects cannot be sufficiently obtained, while when it exceeds 1% by weight, the cost of the raw material increases significantly.

[029] Arsenic is an optional element that constitutes 0% to 0.05% of the steel of the present invention. As is a grain boundary segregation element and has the effect of improving texture, thus reducing iron loss. The above effect is obtained by adding at least 0.001% by weight. However, As is an element that causes grain boundary embrittlement, and this adverse effect becomes particularly noticeable when added in more than 0.05% by weight. Therefore, it is preferable to add As in the range of 0.001 to 0.05% by weight.

[030] Nickel may be added as an optional element in an amount of 0% to 1% to increase the strength of the steel of the present invention and improve its strength and elongation. However, when its content Petition 870250098838, dated 10 / 29 / 2025, page 16 / 32 8 / 14 is greater than 1%, nickel causes deterioration of ductility. In a preferred embodiment, the nickel content remains below 0.04%.

[031] Copper may be added as an optional element in an amount of 0% to 1% to increase the strength and elongation of the steel of the present invention. However, when its content is greater than 1%, it may degrade the surface characteristics. In a preferred embodiment, the copper content is at least 0.01%.

[032] Boron is an optional element for the steel of the present invention and may be present from 0% to 0.05%. Boron forms boron nitrides and imparts additional strength to the steel of the present invention when added in an amount of at least 0.0001%.

[033] Calcium may optionally be present in the steel of the present invention, ranging from 0.001% to 0.01%. Calcium contributes to the refining of the steel by binding the harmful sulfur content in globular form, thereby delaying the harmful effects of sulfur.

[034] Other elements, such as Sn, Pb or Sb, may be added individually or in combination in the following proportions: Sn ^ 0.2%, Pb ^ 0.2% and Sb ^ 0.2%. Up to the maximum indicated levels, these elements allow for grain refinement during solidification. In a preferred embodiment, the Sn content is less than 0.04%.

[035] The remainder of the steel composition consists of iron and unavoidable impurities resulting from processing.

[036] The microstructure of non-oriented electrical steel will now be described in detail, with all percentages expressed as area fractions.

[037] The microstructure is made of ferrite. The steel of the present invention has a recrystallized microstructural region of 80% to 100% by area fraction, with grains with an average size of 20 microns to 110 microns. The recrystallized structure with a high degree of recrystallization is due to Petition 870250098838, dated 10 / 29 / 2025, page 17 / 32 9 / 14 Homogeneous silicon enrichment, which improves the magnetic properties of the steel of the present invention. A controlled grain size ensures mechanical properties in both the transverse and lamination directions. The preferred degree of recrystallization is 90% to 100%. The preferred average grain size for the present invention is 20 microns to 100 microns and, more preferably, 20 microns to 90 microns.

[038] The steel of the present invention may have a non-recrystallized microstructural region of 0% to 20% by area fraction and the preferred degree of non-recrystallization is 0% to 10% and more preferably 0% to 5%.

[039] In addition to the microstructure mentioned above, the microstructure of non-oriented electrical steel is free of microstructural components such as martensite, bainite, pearlite and cementite.

[040] The steel according to the invention can be manufactured by any suitable methods. However, it is preferable to use the method according to the invention that will be detailed, as a non-limiting example.

[041] This preferred method consists of providing a semi-finished steel casting with the chemical composition of the steel according to the invention. The casting can be done in ingots or continuously in the form of plates or thin strips, i.e., with a thickness ranging from approximately 240 mm or less for any type of casting.

[042] For example, the plate-shaped casting is cast with the chemical composition according to the invention and then reheated, with the reheating temperature of the plate varying from 1050 °C to 1250 °C until the temperature becomes homogeneous throughout the plate. Below 1050 °C, rolling becomes difficult and the forces exerted on the rolling mill are too high. Above 1250 °C, high-content silicons become too soft and may exhibit some sagging, making handling difficult. Preferably, Petition 870250098838, dated 10 / 29 / 2025, page 18 / 32 10 / 14 the reheating temperature of the plate is 1100 °C to 1200 °C and, more preferably, 1150 °C to 1200 °C.

[043] Subject the reheated plate to hot rolling, where the finishing temperature of the hot rolling influences the final hot-rolled microstructure and occurs from 750 °C to 850 °C. When the finishing rolling temperature is below 750 °C, recrystallization is limited and the microstructure is highly deformed. Above 850 °C, there would be more impurities in the solid solution and, consequently, precipitation and deterioration of magnetic properties. Preferably, the finishing rolling temperature is from 780 °C to 850 °C and, more preferably, from 800 °C to 850 °C.

[044] The hot-rolled steel sheet obtained in this manner is then immediately cooled at a cooling rate of at least 10 °C / s to the coiling temperature of the hot-rolled steel sheet, which also plays a role in the hot-rolled steel sheet; it occurs from 480 °C to 560 °C. Coiling at temperatures below 625 °C will not have the proper distribution and size of precipitates for the steel of the present invention. Above 560 °C, a thick oxide layer will form, which will cause difficulties for subsequent processing steps such as cold rolling and / or pickling. Preferably, the cooling rate will be less than or equal to 200 °C / s, more preferably, the cooling rate will be 12 °C / s to 75 °C / s. Preferably, the winding temperature will be between 490 °C and 550 °C, and more preferably between 500 °C and 550 °C.

[045] The hot-rolled coiled steel sheet is then cooled to ambient temperature before undergoing optional hot band annealing.

[046] Hot-rolled steel sheet may undergo an optional descaling step to remove formed scale. Petition 870250098838, dated 10 / 29 / 2025, p. 19 / 32 11 / 14 during hot rolling before optional hot band annealing. The hot-rolled sheet can then be subjected to optional hot band annealing, carried out at temperatures of 650 °C to 1100 °C, preferably for at least 10 seconds and no more than 96 hours, the temperature preferably remaining between 700 °C and 1070 °C and, more preferably, between 720 °C and 1050 °C. Subsequently, an optional scale removal step from this hot-rolled steel sheet can be carried out by means of, for example, pickling of such sheet.

[047] Thus, the resulting hot-rolled steel sheet may optionally have thicknesses of 0.8 mm to 3.5 mm and preferably of 0.9 mm to 3 mm and, more preferably, of 1 mm to 2.8 mm.

[048] This hot-rolled steel sheet is then subjected to cold rolling to obtain a cold-rolled steel sheet with a thickness reduction of 50 to 95%. Preferably, the thickness reduction is 60% to 95%, and more preferably 75% to 95%.

[049] After that, the cold-rolled steel sheet is heat treated, which will give the steel of the present invention the necessary mechanical properties and microstructure.

[050] The cold-rolled steel sheet is then subjected to heating, wherein the heating begins at ambient temperature, the cold-rolled steel sheet being heated, at a heating rate HR1 of at least 1 °C / s, to the annealing temperature Tsoak, which varies from 980 °C to 1150 °C, preferably from 990 °C to 1100 °C and, more preferably, from 990 °C to 1050 °C. In a preferred embodiment, the heating rate HR1 for heating is at least 2 °C / s, more preferably, at least 5 °C / s.

[051] Cold-rolled steel sheet is held in Tsoak for 10 seconds to 5,000 seconds to ensure 80% to 100% recrystallization. Petition 870250098838, dated 10 / 29 / 2025, p. 20 / 32 12 / 14

[052] The cold-rolled steel sheet is then cooled, where the cooling begins in the Tsoak, the cold-rolled steel sheet being cooled, at a cooling rate CR1 of 1 °C / s 150 °C / s, to a temperature T1 which is in the range of 20 °C to 300 °C. In a preferred embodiment, the cooling rate CR1 is 3 °C / s 120 °C / s. The preferred temperature T1 is 20 °C to 200 °C.

[053] The cold-rolled steel sheet thus obtained has a thickness of 0.24 mm to 0.29 mm and, more preferably, of 0.24 mm to 0.28 mm and, even more preferably, of 0.24 mm to 0.27 mm.

[054] Next, the cold-rolled steel sheet is cooled to room temperature to obtain an electrical steel sheet without orientation.

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

[056] The following tests, examples, figurative examples and tables presented here are not restrictive in nature and should be considered only for illustrative purposes and will exhibit the advantageous features of the present invention.

[057] Steel sheets made from steels with different compositions are grouped in Table 1, where the steel sheets are produced according to the process parameters stipulated in Table 2, respectively. Subsequently, Table 3 gathers the results of the evaluations of the properties obtained.

[058] All steels in Table 1 showed a nitrogen content below 0.09%.

[059] Table 2 lists the parameters of the rolling process. Petition 870250098838, dated 10 / 29 / 2025, page 21 / 32 13 / 14 hot rolling and annealing implemented in cold-rolled steel sheets to give the steels of Table 1 the mechanical and magnetic properties necessary to become non-oriented electrical steels. All steels of the invention, I1 and I2, are cooled after hot rolling at a cooling rate of 15 °C / s. Furthermore, for the inventive examples, the reduction in cold rolling is 80% and, subsequently, the heating rate UR1 to the immersion temperature in annealing is 5 °C / s. The temperature T1 for all inventive examples is 25 °C, while the cooling rate CR1 is 5 °C / s.

[060] All steels produced according to the parameters in Table 2 showed recrystallized microstructure, with more than 95% recrystallization and with a particle size of 20 to 110 µm. Table 1 Steel C Mn Si Al SP Cr Cu I1 0.0022 0.21 3.25 0.88 0.0015 0.0137 0.0334 0.0291 I2 0.0022 0.20 3.25 0.89 0.0015 0.0137 0.0334 0.0291 Table 2 Tests Reheating (°C) FRT (°C) Winding (°C) HBA (°C) HBA Time (hours) Reduction (%) Tsoak (°C) Annealing Time Cold Rolled Thickness (mm) I1 1160 839 511 800 12 80 1000 40 0.265 I2 1160 839 543 800 12 80 1000 24 0.264 Table 3

[061] The results of the various mechanical tests conducted in accordance with the standards are compiled. The ultimate tensile strength, total elongation, and yield strength are measured in accordance with NF EN ISO 6892-1 standards, and the J50 magnetic properties and total iron losses at 1T and 400 Hz were measured in accordance with IEC 60404-2 standards. Eddy current losses are calculated according to the Bertotti Method published in the article entitled “General Properties of Power Losses in Soft Petition 870250098838, dated 10 / 29 / 2025, page 22 / 32 14 / 14 "Ferromagnetic Materials" by Giorgio Berttoti published in IEEE TRANSACTIONS ON MAGNETICS, Vol. 24, No. 1, January 1988. Equation 2 identifies classical losses that are called (Pclass) which for the purpose of this invention is referred to as eddy current losses.

[062] The average grain size of the recrystallized microstructure is measured according to ASTM E112 96(02) standards using the linear intercept method. Tensile Strength (MPa) Yield Strength (MPa) Total Elongation (%) J50 (T) P1T / 400Hz (W / Kg) % of eddy current losses RD TD RD TD RD TD I1 539 553 419 430 20.80 19.00 1.682 12.9 33.3 I2 536 551 417 429 18.10 18.60 1.666 13.0 33.0 Petition 870250098838, dated 10 / 29 / 2025, p. 23 / 32

Claims

1 / 4 Claims 1. NON-ORIENTED ELECTRICAL STEEL SHEET, characterized by having a thickness of 0.24 mm to 0.29 mm and a composition comprising the following elements, expressed as a percentage by weight: 0.0001% < Carbon < 0.005% 0.2% < Manganese < 0.3% 3.1% < Silicon < 3.6% 0.6% < Aluminum < 1% Phosphorus < 0.15% Sulfur < 0.006% Nitrogen < 0.09% 0.01% < Chromium < 1% 0.01% < Copper < 1% and contains one or more of the following optional elements 0% < Vanadium < 0.1% 0% < Molybdenum < 0.5% 0% < Tungsten < 0.1% 0% < Cobalt < 1% 0% < Arsenic < 0.05% 0.001% < Calcium < 0.01% 0% < Nickel < 1% 0% < Boron < 0.05% 0% < Lead < 0.2% 0% < Tin < 0.2% 0% < Antimony < 0.2% the remaining composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet being made of ferrite and comprising, in area fraction, 80% to 100% of Petition 870250098838, of 10 / 29 / 2025, page.24 / 32 2 / 4 recrystallized microstructure, 0% to 20% non-recrystallized microstructure, where the average grain size of the recrystallized microstructure is 20 microns to 110 microns and presents a percentage of eddy current losses in relation to the total iron losses, measured at 1 T and 400 Hz, according to IEC 60404-2 standards, of 30% to 35%, when calculated according to the Bertotti method.

2. NON-ORIENTED ELECTRICAL STEEL SHEET, according to claim 1, characterized by its composition including 3.1% to 3.5% silicon.

3. NON-ORIENTED ELECTRICAL STEEL SHEET, according to any one of claims 1 to 2, characterized by its composition including from 0.001% to 0.004% carbon.

4. NON-ORIENTED ELECTRICAL STEEL SHEET, according to any one of claims 1 to 3, characterized by its composition including 0.7% to 0.9% aluminum.

5. NON-ORIENTED ELECTRICAL STEEL SHEET, according to any one of claims 1 to 4, characterized by its composition including from 0.2% to 0.27% manganese.

6. NON-ORIENTED ELECTRICAL STEEL SHEET, according to any one of claims 1 to 5, characterized in that the amount of non-recrystallized microstructure is from 0% to 10%.

7. NON-ORIENTED ELECTRICAL STEEL SHEET, according to any one of claims 1 to 6, characterized in that the amount of recrystallized microstructure is 90% to 100%.

8. NON-ORIENTED ELECTRICAL STEEL SHEET, according to any one of claims 1 to 7, characterized in that the steel sheet has an ultimate tensile strength of at least 500 MPa in both the transverse and rolling directions. Petition 870250098838, dated 10 / 29 / 2025, page 25 / 32 3 / 4 9. NON-ORIENTED ELECTRICAL STEEL SHEET, according to any one of claims 1 to 8, characterized by having a yield strength of 380 MPa or more in both the transverse and rolling directions.

10. NON-ORIENTED ELECTRICAL STEEL SHEET, according to any one of claims 1 to 9, characterized in that the steel sheet has a total elongation of at least 17% in both the transverse and rolling directions.

11. METHOD FOR PRODUCING A NON-ORIENTED ELECTRICAL STEEL SHEET, as defined in any one of claims 1 to 10, characterized by comprising the following successive steps: - providing a steel composition, as defined in any one of claims 1 to 5; - reheating the semi-finished product to a temperature of 1050 °C to 1250 °C; - rolling the semi-finished product where the hot rolling finish temperature shall be 750 °C to 850 °C to obtain a hot-rolled steel sheet; - cooling the hot-rolled sheet immediately after hot rolling finish; - then the hot-rolled steel sheet is cooled from the hot rolling finish to a coiling temperature range of 480 °C to 560 °C at a cooling rate of at least 10 °C / s; - Subsequently, coil the hot-rolled steel sheet within the coiling temperature range of 480 °C to 560 °C;- optionally perform scale removal process on Petition 870250098838, dated 10 / 29 / 2025, page 26 / 32 4 / 4 hot-rolled steel sheet; - optionally perform hot band annealing on hot-rolled steel sheet from 650 °C to 1100 °C for 10 seconds to 96 hours; - optionally perform scale removal process on hot-rolled steel sheet; - cold roll the hot-rolled steel sheet with a reduction rate of 50 to 95% to obtain a cold-rolled steel sheet;- Subsequently, annealing the cold-rolled steel sheet begins with heating for annealing from room temperature to an annealing temperature range (Tsoak) of 980°C to 1150°C, with a heating rate (HR1) of at least 1°C / s; - then performing annealing at the annealing temperature for 10 to 5000 seconds; - then cooling the cold-rolled steel sheet from the annealing temperature to a temperature (T1) of 300°C to 20°C, with a cooling rate (CR1) of 1°C / s to 150°C / s; - then cooling to room temperature to obtain a non-oriented electrical steel sheet.

12. METHOD, according to claim 11, characterized in the Tsoak temperature for annealing being from 990 °C to 1090 °C.

13. METHOD, according to any one of claims 11 to 12, characterized in that the temperature T1 is from 200 °C to 20 °C.

14. METHOD, according to any one of claims 11 to 13, characterized in that the cooling rate CR1 is 3 °C / s 120 °C / s. Petition 870250098838, dated 10 / 29 / 2025, p. 27 / 32