Non-oriented electrical steel sheet and method for manufacturing same

Abstract

A non-oriented electrical steel sheet according to one embodiment of the present invention comprises, by wt%, 1.5-5.0% of Si, 0.1-2.5% of Al, 0.1-2.5% of Mn, and the balance of Fe and inevitable impurities, and satisfies formula 1. [Formula 1] 0.45 ≤ (VA+VB+VC) / (VD+VE+VF) ≤ 1.45 (In formula 1, VA, VB, VC, VD, VE and VF represent the area fraction (%) of the textures with orientations within 15° from (001)[0-10], (001)[-1-10], (100)[025], (223)[1-10], (111)[3-41] and (112)[1-10]), respectively.

Description

Non-oriented electrical steel sheet and its manufacturing method One embodiment of the present invention relates to a non-oriented electrical steel sheet and a method for manufacturing the same. Specifically, one embodiment of the present invention relates to a non-oriented electrical steel sheet and a method for manufacturing the same, which simultaneously improves strength and magnetism by developing a specific aggregate structure by controlling the reduction ratio of each pass in finishing rolling during a hot-rolled sheet manufacturing process. Non-oriented electrical steel is mainly used in motors that convert electrical energy into mechanical energy, and in this process, excellent magnetic properties of non-oriented electrical steel are required to achieve high efficiency. In particular, as eco-friendly cars driven by motors instead of internal combustion engines have been gaining attention recently, demand for non-oriented electrical steel used as a drive motor core material is increasing, and for this purpose, non-oriented electrical steel with excellent magnetic properties and strength is required. The magnetic properties of non-oriented electrical steel sheets are mainly evaluated by iron loss and magnetic flux density. Iron loss refers to the energy loss that occurs at a specific magnetic flux density and frequency, and magnetic flux density refers to the degree of magnetization obtained under a specific magnetic field. The lower the iron loss, the more energy-efficient the motor can be manufactured under the same conditions, and the higher the magnetic flux density, the more miniaturized the motor or reduced the copper loss. Therefore, using non-oriented electrical steel sheets with low iron loss and high magnetic flux density, a drive motor with excellent efficiency and torque can be manufactured, which can improve the driving range and output of eco-friendly vehicles. The characteristics of non-oriented electrical steel sheets that should be considered also vary depending on the operating conditions of the motor. As a general standard for evaluating the characteristics of non-oriented electrical steel sheets used in motors, W15 / 50, which is the iron loss when a 1.5T magnetic field is applied at a commercial frequency of 50Hz, is widely used. However, in the case of non-oriented electrical steel sheets with a thickness of 0.35mm or less used in eco-friendly vehicle drive motors, magnetic characteristics are often important at low fields of 1.0T or less and high frequencies of 400Hz or higher, so W 10 / 400 The characteristics of non-oriented electrical steel sheets are often evaluated by iron loss. In addition, strength characteristics, which were not considered important in the past, are also evaluated as important characteristics due to the increase in rotation speed. Therefore, reflecting the recent energy efficiency improvement policy and the direction of utilization of non-oriented electrical steel sheets, it can be said that the development technology of non-oriented electrical steel sheets with low high-frequency iron loss, high magnetic flux density, and excellent strength is essential. The most basic and efficient way to reduce iron loss among the important magnetic properties of non-oriented electrical steel sheets is to increase the amount of Si, Al, and Mn, which are elements with high resistivity, or to make the steel sheet thinner. Increasing the amount of Si, Al, and Mn increases the resistivity of the steel, which reduces the eddy current loss among the iron loss of non-oriented electrical steel sheets, thereby reducing iron loss. In the case of high-frequency iron loss, the proportion of eddy current loss among the iron loss is greater, so it can be a very effective method for reducing high-frequency iron loss. However, the effect varies depending on the addition ratio, and the magnetic flux density deteriorates as the amount of alloying elements increases, so in order to secure excellent iron loss and magnetic flux density, the appropriate amount of addition and the addition ratio between the Si, Al, and Mn additions must be appropriately controlled. The method of making the thickness thinner is also a method that greatly reduces eddy current loss, and is very effective in reducing iron loss, but thin steel sheets have the disadvantage of poor productivity and workability. Various technologies have been reported to improve the magnetic flux density while lowering the core loss of non-oriented electrical steel sheets, such as improving the texture by utilizing special additive elements such as REM to improve the magnetic properties, or introducing additional manufacturing processes such as warm rolling, double rolling, and double annealing. However, all of these technologies cause an increase in manufacturing cost or are accompanied by difficulties in mass production, so it can be said that there is a need to develop a technology that is both excellent in magnetism and easy to produce commercially. In addition, technologies are being developed to suppress and control the formation of inclusions by minimizing the addition of impurities and adding elements such as Ca, but these also cause an increase in manufacturing cost and it is not easy to clearly secure their effects. The strength of steel plates tends to increase as the alloy content increases. However, since Si, Al, etc. are brittle elements and have different effects on strength, the content and ratio of the components must be optimized to secure high strength characteristics. On the other hand, the finer the grain size, the higher the strength, but there is an optimal grain size that minimizes iron loss, so in order to secure both low iron loss and high strength characteristics, a technology to appropriately control the grain size is also necessary. One embodiment of the present invention provides a non-oriented electrical steel sheet and a method for manufacturing the same. Specifically, one embodiment of the present invention provides a non-oriented electrical steel sheet and a method for manufacturing the same, which simultaneously improves strength and magnetism by developing a specific aggregate structure by controlling the reduction ratio of each pass in finishing rolling during a hot-rolled sheet manufacturing process. A non-oriented electrical steel sheet according to one embodiment of the present invention contains, in wt%, Si: 1.5 to 5.0%, Al: 0.1 to 2.5%, and Mn: 0.1 to 2.5%, with the remainder being Fe and unavoidable impurities, and satisfies the following equation 1. [Formula 1] 0.45 ≤ (VA+VB+VC) / (VD+VE+VF) ≤ 1.45 (In Equation 1, VA, VB, VC, VD, VE, and VF are (001)[0-10], (001)[-1-10], (100) respectively.

[0025] , (223)[1-10], (111)[3-41], and (112)[1-10], which represents the area fraction (%) of the aggregates having orientations within 15°. A non-oriented electrical steel sheet according to one embodiment of the present invention can satisfy the following equation 2. [Formula 2] 0.35 ≤ VC / VE ≤ 1.35 (In Equation 2, VC and VE represent the area fraction (%) of the aggregate structure having orientations within 15° from (100)

[0025] and (111)[3-41], respectively.) A non-oriented electrical steel sheet according to one embodiment of the present invention may further include at least one of P: 0.1 wt% or less (excluding 0%), C: 0.005 wt% or less (excluding 0%), S: 0.005 wt% or less (excluding 0%), Ti: 0.005 wt% or less (excluding 0%), and N: 0.005 wt% or less (excluding 0%). A non-oriented electrical steel sheet according to one embodiment of the present invention may further contain 0.005 to 0.200 wt% of each or a combined amount of one or more of Sn, Sb, Bi, Pb, Ge, and As. A non-oriented electrical steel sheet according to one embodiment of the present invention may further include at least one of Cu: 0.005 to 0.2 wt%, Cr: 0.01 to 0.5 wt%, Ni: 0.05 wt% or less (excluding 0%), Zn: 0.01 wt% or less (excluding 0%), and Co: 0.05 wt% or less (excluding 0%). A non-oriented electrical steel sheet according to one embodiment of the present invention may further include at least one of Mo: 0.03 wt% or less (excluding 0%), B: 0.0050 wt% or less (excluding 0%), V: 0.0050 wt% or less (excluding 0%), Ca: 0.0050 wt% or less (excluding 0%), Nb: 0.0050 wt% or less (excluding 0%), Zr: 0.005 wt% or less (excluding 0%), Te: 0.01 wt% or less (excluding 0%), and Mg: 0.0050 wt% or less (excluding 0%). A non-oriented electrical steel sheet according to one embodiment of the present invention may have a resistivity (ρ) of 63 μΩ·cm or more at 25°C. According to one embodiment of the present invention, a non-oriented electrical steel sheet may have a core loss (W10 / 400) of 12.0 W / Kg or less and a magnetic flux density (B50) of 1.60 T or more. A method for manufacturing a non-oriented electrical steel sheet according to one embodiment of the present invention comprises the steps of: hot-rolling a slab containing, in wt%, Si: 1.5 to 5.0%, Al: 0.1 to 2.5%, and Mn: 0.1 to 2.5%, with the remainder being Fe and unavoidable impurities, to manufacture a hot-rolled steel sheet; cold-rolling the hot-rolled steel sheet to manufacture a cold-rolled sheet; and a cold-rolled sheet annealing step of annealing the cold-rolled sheet. The step of manufacturing a hot rolled steel sheet includes a rough rolling step and a finish rolling step, and the finish rolling step is performed through n passes, where n is 2 or more, and satisfies Equation 3. [Formula 3] R1 / (R1+R2+……+Rn) ≥ 0.2 (In Equation 3, R1 to Rn represent the pressure reduction ratios (%) of the 1st to nth passes, respectively.) The thought rolling step can satisfy the following equation 4. [Formula 4] R1 / Rn ≤ 8 (In Equation 4, R1 and Rn represent the pressure reduction ratios (%) of the 1st and nth passes, respectively.) The first pass reduction ratio (R1) in the rolling process can be 35 to 80%. The reduction ratio (Rn) of the last pass in the rolling process can be between 7 and 35%. The slab may further contain at least one of P: 0.1 wt% or less (excluding 0%), C: 0.005 wt% or less (excluding 0%), S: 0.005 wt% or less (excluding 0%), Ti: 0.005 wt% or less (excluding 0%), and N: 0.005 wt% or less (excluding 0%). The slab may further contain 0.005 to 0.200 wt% of each or a combination of one or more of Sn, Sb, Bi, Pb, Ge and As. The slab may further contain at least one of Cu: 0.005 to 0.2 wt%, Cr: 0.01 to 0.5 wt%, Ni: 0.05 wt% or less (excluding 0%), and Zn: 0.01 wt% or less (excluding 0%). The slab may further include at least one of Mo: 0.03 wt% or less (excluding 0%), B: 0.0050 wt% or less (excluding 0%), V: 0.0050 wt% or less (excluding 0%), Ca: 0.0050 wt% or less (excluding 0%), Nb: 0.0050 wt% or less (excluding 0%), Zr: 0.005 wt% or less (excluding 0%), Te: 0.01 wt% or less (excluding 0%), Co: 0.05 wt% or less (excluding 0%), and Mg: 0.0050 wt% or less (excluding 0%). A non-oriented electrical steel sheet according to one embodiment of the present invention has an improved aggregate structure, thereby simultaneously exhibiting excellent magnetic flux density, iron loss, and yield strength. Ultimately, the non-oriented electrical steel sheet according to one embodiment of the present invention contributes to the manufacture of eco-friendly automobile motors, high-efficiency home appliance motors, and super premium-grade electric motors. The terms first, second, and third, etc. are used to describe, but are not limited to, various parts, components, regions, layers, and / or sections. These terms are only used to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Thus, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms include the plural forms as well, unless the context clearly dictates otherwise. The word "comprising," as used herein, specifies particular features, regions, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of other features, regions, integers, steps, operations, elements, and / or components. When a part is referred to as being "on" or "on" another part, it may be directly on or above the other part, or there may be other parts intervening. In contrast, when a part is referred to as being "directly on" another part, there are no other parts intervening. Also, unless otherwise specified, % means weight%, and 1 ppm is 0.0001 weight%. In one embodiment of the present invention, the inclusion of an additional element means including the remainder of iron (Fe) in an amount equivalent to the additional amount of the additional element. Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries are additionally interpreted as having a meaning consistent with the relevant technical literature and the presently disclosed content, and are not interpreted in an ideal or very formal sense unless defined. Hereinafter, embodiments of the present invention will be described in detail so that those with ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. A non-oriented electrical steel sheet according to one embodiment of the present invention contains Si: 1.5 to 5.0% by weight, Al: 0.1 to 2.5%, and Mn: 0.1 to 2.5% by weight, with the remainder being Fe and unavoidable impurities. Below, the reasons for the limitation of the components of non-oriented electrical steel sheets are explained. Si: 1.50 to 5.00 wt% Silicon (Si) increases the resistivity of the material, thereby reducing iron loss, and increases strength through solid solution strengthening. If too little Si is added, the iron loss and strength improvement effects may be insufficient. If too much Si is added, the magnetic flux density may decrease significantly and the rollability may become inferior due to increased brittleness. Therefore, Si may be included in an amount of 1.5 to 5.0 wt%. More specifically, it may be included in an amount of 2.50 to 4.50 wt%. More specifically, it may be included in an amount of 2.70 to 3.85 wt%. Al: 0.10 to 2.50 wt% Aluminum (Al) increases the resistivity of the material, thereby lowering iron loss and improving rollability, and reduces magnetic anisotropy, thereby reducing magnetic deviation in the rolling direction and the direction perpendicular to the rolling direction. If too little Al is added, it may be difficult to obtain the effect of reducing high-frequency iron loss. If too much Al is added, nitrides may be excessively formed, which may deteriorate magnetism. Therefore, Al may be included in an amount of 0.10 to 2.50 wt%. More specifically, it may be included in an amount of 0.50 to 2.50 wt%. More specifically, it may be included in an amount of 0.60 to 2.30 wt%. Mn: 0.10 to 2.50 wt% Manganese (Mn) improves iron loss by increasing the resistivity of the material and plays a role in improving the aggregate structure. If too little Mn is added, fine sulfides are formed, causing magnetic deterioration, and if too much Mn is added, it can have a negative effect on the magnetic flux density. Therefore, Mn may be included in an amount of 0.10 to 2.50 wt%. More specifically, it may be included in an amount of 0.2 to 1.8 wt%. More specifically, it may be included in an amount of 0.50 to 2.50 wt%. In one embodiment of the present invention, the non-oriented electrical steel sheet may have a resistivity of 63.0 μΩ cm or more at 25°C. The iron loss of the non-oriented electrical steel sheet is divided into hysteresis loss and eddy current loss. By adding elements such as Si, Al, and Mn, the resistivity of the steel increases, and the eddy current loss can be significantly reduced. In particular, as the frequency increases, the proportion of the total iron loss occupied by the eddy current loss increases. Therefore, in order to obtain excellent high-frequency iron loss, it is necessary to control the resistivity of the steel to a certain level or more. Through the present invention, when the resistivity (ρ) of the steel is 63 μΩ cm or more, excellent characteristics can be secured. More specifically, the resistivity (ρ) can be 64.0 to 90.0 μΩ cm. In one embodiment of the present invention, resistivity can be measured using a 4-point method, etc. A non-oriented electrical steel sheet according to one embodiment of the present invention may further include at least one of P: 0.1 wt% or less (excluding 0%), C: 0.005 wt% or less (excluding 0%), S: 0.005 wt% or less (excluding 0%), Ti: 0.005 wt% or less (excluding 0%), and N: 0.005 wt% or less (excluding 0%). P: 0.1 wt% or less Phosphorus (P) is an element that improves the grain structure of steel by segregating grain boundaries and surfaces. However, if too much P is added, it may lower the iron loss by suppressing grain growth and lower the rolling property due to grain boundary segregation, which may also lower the productivity. More specifically, P may be included in an amount of 0.0001 to 0.0500 wt%. More specifically, P may be included in an amount of 0.0020 to 0.0200 wt%. C: 0.0050 wt% or less Carbon (C) can cause magnetic aging and combine with other impurity elements to form carbides, thereby hindering grain boundary or domain wall movement and deteriorating magnetic properties. More specifically, C can be included in an amount of 0.0005 to 0.0035 wt%. S: 0.0050 wt% or less Sulfur (S) can form fine precipitates, MnS and CuS, thereby deteriorating magnetic properties and hot workability. More specifically, S can be included in an amount of 0.0005 to 0.0040 wt%. Ti: 0.0050 wt% or less Titanium (Ti) has a very strong tendency to form precipitates inside the steel, and can deteriorate iron loss by forming fine carbides, nitrides, or sulfides inside the parent material, thereby inhibiting grain growth and domain wall movement. More specifically, it can contain 0.0005 to 0.0035 wt% of Ti. N: 0.0050 wt% or less Nitrogen (N) not only forms fine AlN precipitates inside the parent material, but also combines with other impurities to form fine precipitates, thereby inhibiting grain growth and domain wall movement, thereby worsening iron loss. More specifically, N may be included in an amount of 0.0005 to 0.0040 wt%. A non-oriented electrical steel sheet according to one embodiment of the present invention may further contain 0.005 to 0.200 wt% of each or a combined amount of one or more of Sn, Sb, Bi, Pb, Ge, and As. Sn Tin (Sn) can be added to improve magnetism because it improves the aggregate structure of the material by segregating at grain boundaries and surfaces and plays a role in suppressing surface oxidation. If too much Sn is added, grain boundary segregation becomes severe, deteriorating the surface quality, increasing the hardness and causing fracture of the cold-rolled sheet, which can reduce the rollability. Specifically, Sn can be further included in an amount of 0.005 to 0.200 wt%. More specifically, it can be further included in an amount of 0.010 to 0.080 wt%. Sb Antimony (Sb) improves the material's aggregate structure by segregating at grain boundaries and surfaces and suppresses surface oxidation, so it can be additionally added to improve magnetism. If too much Sb is added, grain boundary segregation becomes severe, deteriorating the surface quality, increasing the hardness and causing breakage of the cold-rolled sheet, which can reduce the rollability. Specifically, 0.005 to 0.200 wt% of Sb can be further included. More specifically, 0.010 to 0.080 wt% can be further included. Bi, Pb, Ge and As When added, bismuth (Bi), lead (Pb), germanium (Ge) and arsenic (As) segregate at grain boundaries, thereby relieving stress concentration at grain boundaries during cold rolling, and thus reducing stress concentration in the subsequent process of recrystallization annealing. <111> / ND By suppressing the recrystallization of the orientation grains, the magnetic flux density is improved. If these are added appropriately, the aforementioned effects can be additionally obtained, but if they are included in too much, a large amount of segregation may occur, suppressing grain growth and thus lowering the magnetic flux density and iron loss. A non-oriented electrical steel sheet according to one embodiment of the present invention may further include at least one of Cu: 0.005 to 0.2 wt%, Cr: 0.01 to 0.5 wt%, Ni: 0.05 wt% or less (excluding 0%), Zn: 0.01 wt% or less (excluding 0%), and Co: 0.05 wt% or less (excluding 0%). Cu: 0.005 to 0.200 wt% Copper (Cu) plays a role in forming sulfides with Mn. If Cu is added more, if too little is added, (Cu Mn)S may be finely precipitated, which may deteriorate magnetism. If too much Cu is added, high-temperature embrittlement may occur, which may form cracks during rolling or hot rolling. More specifically, Cu may be included in an amount of 0.01 to 0.10 wt%. Cr: 0.01 to 0.50 wt% Chromium (Cr) plays a role in improving iron loss by increasing resistivity. If too little Cr is added, the resistivity-increasing effect may not be sufficient. If too much Cr is included, the magnetic flux density may decrease. More specifically, Cr may be included in an amount of 0.050 to 0.20 wt%. Ni: 0.05 wt% or less Nickel (Ni) may react with impurity elements to form fine sulfides, carbides, and nitrides, which may have a detrimental effect on magnetism. More specifically, it may contain 0.001 to 0.03 wt% of Ni. Zn: 0.01 wt% or less Zinc (Zn) may act as an impurity and deteriorate magnetism when the content is excessive. Therefore, Zn may be added more within the above-mentioned range. More specifically, Zn may be included in an amount of 0.001 to 0.005 wt%. Co: 0.05 wt% or less Cobalt (Co) does not form fine-sized precipitates that reduce the magnetism of steel plates, but it can increase high-temperature strength and cause poor coil shape after hot rolling. A non-oriented electrical steel sheet according to one embodiment of the present invention may further include at least one of Mo: 0.03 wt% or less (excluding 0%), B: 0.0050 wt% or less (excluding 0%), V: 0.0050 wt% or less (excluding 0%), Ca: 0.0050 wt% or less (excluding 0%), Nb: 0.0050 wt% or less (excluding 0%), Zr: 0.0050 wt% or less (excluding 0%), Te: 0.0100 wt% or less (excluding 0%), and Mg: 0.0050 wt% or less (excluding 0%). Mo: 0.030 wt% or less Molybdenum (Mo) may suppress segregation of segregating elements when added in excess, thereby reducing the effect of improving the grain structure. Therefore, Mo may be included at 0.03 wt% or less. The lower limit is not particularly limited, but since it plays a role in improving the grain structure by segregating on the surface and grain boundaries, it may be included at 0.001 wt% or more. More specifically, Mo may be included at 0.001 to 0.010 wt%. More specifically, Mo may be included at 0.005 to 0.010 wt%. B: 0.0050 wt% or less If boron (B) is added in excessive amounts, it may cause deterioration of magnetism through the formation of inclusions in the steel. Therefore, B may be included in an amount of 0.005 wt% or less. The lower limit is not particularly limited, but may be 0.0001 wt% due to steelmaking costs. More specifically, B may be included in an amount of 0.0001 to 0.0030 wt%. V: 0.0050 wt% or less Vanadium (V) has a very strong tendency to form precipitates inside the steel, and forms fine carbides or nitrides inside the parent material, thereby inhibiting grain growth and domain wall movement, thereby deteriorating iron loss. Therefore, the V content may be 0.0050 wt% or less, respectively. The lower limit is not particularly limited, but may be 0.0003 wt% due to steelmaking costs. That is, V may be included in an amount of 0.0003 to 0.0050 wt%. More specifically, V may be included in an amount of 0.0003 to 0.0030 wt%. Ca: 0.0050 wt% or less Calcium (Ca) has a very strong tendency to form precipitates within the steel, and forms fine sulfides within the parent metal, which inhibits grain growth and domain wall movement, thereby deteriorating iron loss. Nb: 0.0050 wt% or less Niobium (Nb) has a very strong tendency to form precipitates inside steel, and forms fine carbides or nitrides inside the base metal, thereby inhibiting grain growth and domain wall movement, thereby deteriorating iron loss. Therefore, the Nb content may be 0.0050 wt% or less. The lower limit is not particularly limited, but may be 0.0003 wt% due to steelmaking costs. That is, Nb may be included in an amount of 0.0003 to 0.0050 wt%. More specifically, Nb may be included in an amount of 0.0003 to 0.0030 wt%. Zr: 0.0050 wt% or less If zirconium (Zr) is added in excessive amounts, it may cause deterioration of magnetism through the formation of inclusions in the steel, etc. Therefore, Zr may be included in an amount of 0.005 wt% or less. The lower limit is not particularly limited, but may be set to 0.0001 wt% due to steelmaking costs. That is, Zr may be included in an amount of 0.0001 to 0.0050 wt%. More specifically, it may be included in an amount of 0.0005 to 0.0030 wt%. Te: 0.0100 wt% or less Tellurium (Te) can be added to prevent the oxide layer fractured during rolling from being pressed into the base metal and being removed by diffusing into the oxide layer on the surface of a hot-rolled coil and increasing the coefficient of friction between the oxide layer and the rolling work rolls, while being concentrated under the oxide layer to improve hardness. If the amount of Te added is too small, the effect may be minimal. If too much Te is added, the oxide layer is easily removed and the base metal comes into direct contact with the work rolls, reducing the effect, and during cold rolling, deformation bands may be excessively generated in the steel sheet, which may lead to the development of a {111} / ND texture, which is unfavorable to magnetism. More specifically, tellurium may be included in an amount of 0.0001 to 0.007 wt%. Mg: 0.0050 wt% or less Magnesium (Mg) is an element that mainly forms sulfide by combining with S, and can affect the surface oxide layer of the steel. Therefore, Mg may be included in an amount of 0.0050 wt% or less. The lower limit is not particularly limited, but may be set to 0.0001 wt% due to the cost of steelmaking. That is, Mg may be included in an amount of 0.0001 to 0.0050 wt%. More specifically, it may be included in an amount of 0.0005 to 0.0030 wt%. The remainder includes Fe and unavoidable impurities. The unavoidable impurities are impurities mixed in during the steelmaking step and the manufacturing process of the non-oriented electrical steel sheet, and since this is widely known in the relevant field, a detailed description is omitted. In one embodiment of the present invention, the addition of elements other than the alloy components described above is not excluded, and various elements may be included within a range that does not impair the technical idea of ​​the present invention. When additional elements are further included, they are included in place of the remainder Fe. As described above, in one embodiment of the present invention, a specific aggregate structure can be developed to simultaneously improve strength and magnetism. A non-oriented electrical steel sheet according to one embodiment of the present invention satisfies the following equation 1. [Formula 1] 0.45 ≤ (VA+VB+VC) / (VD+VE+VF) ≤ 1.45 (In Equation 1, VA, VB, VC, VD, VE, and VF represent the area fraction (%) of the aggregate structure having an orientation within 15° from (001)[0-10], (001)[-1-10], (100)

[0025] , (223)[1-10], (111)[3-41], and (112)[1-10], respectively.) In one embodiment of the present invention, the fractions of (001) planes and (111) planes parallel to the rolling plane, which have been mainly examined as textures that greatly affect magnetism in the past, are important, but (223) and (112) planes, which are similar textures, are also important. In one embodiment of the present invention, the fractions and integration degrees of (001)[0-10], (001)[-1-10], (100)

[0025] textures, which are advantageous to magnetization, are strengthened, and the fractions and integration degrees of (223)[1-10], (111)[3-41], (112)[1-10] textures, which are disadvantageous to magnetization, are reduced, thereby improving magnetism. If the value of Equation 1 is too small, magnetization may be inferior, which may increase iron loss. Even if the value of Equation 1 is larger, no additional magnetic improvement occurs, and the process for achieving this may become complicated. More specifically, Equation 1 may be 0.50 to 1.40. In equation 1 (hkl) <uvw>The texture orientation indicated by means of the texture orientation indication in the Miller index notation. The Miller index is a notation used in crystallography to indicate the direction and plane of the crystal lattice, and (hkl) is the plane parallel to the steel sheet rolling plane in the measured texture. Also, the vector <uvw>refers to the direction parallel to the rolling direction in the measurement set structure. In one embodiment of the present invention, the value of Equation 1 can be calculated by observing and analyzing the fraction of the aggregate structure through electron backscatter diffraction (EBSD) measurement and using the results. In order to ensure the reliability of the data, the measurement can be performed so that at least 5,000 crystal grains can be included. The tolerance angle can be set to 15° or less. A non-oriented electrical steel sheet according to one embodiment of the present invention can satisfy the following equation 2. [Formula 2] 0.35 ≤ VC / VE ≤ 1.35 (In Equation 2, VC and VE represent the area fraction (%) of the aggregate structure having orientations within 15° from (100)

[0025] and (111)[3-41], respectively.) Equation 2 is a formula that, among the aggregate structures, (100)

[0025] has a more favorable effect on magnetism, and (111)[3-41] has a more adverse effect on magnetism. If the value of Equation 2 is too small, magnetization may not occur well during magnetization, which may greatly reduce iron loss. Even if the value of Equation 2 is larger, no additional magnetic enhancement occurs, and the process for achieving this may become complicated. More specifically, Equation 2 may be 0.35 to 1.30. As described above, in one embodiment of the present invention, a specific aggregate structure can be developed to simultaneously improve strength and magnetism. Specifically, a non-oriented electrical steel sheet according to one embodiment of the present invention may have a core loss (W10 / 400) of 12.0 W / kg or less and a magnetic flux density (B50) of 1.60 T or more. The thickness standard may be 0.20 mm. More specifically, the core loss (W10 / 400) may be 9.0 to 11.0 W / kg. The magnetic flux density (B50) may be 1.61 to 1.70 T. The iron loss (W10 / 400) is the iron loss when a magnetic flux density of 1.0 T is induced at a frequency of 400 Hz. The magnetic flux density (B50) means a magnetic flux density induced in a magnetic field of 5000 A / m. Iron loss (10 / 400) and magnetic flux density (B50) can be measured with a single sheet tester in the rolling direction and the direction perpendicular to the rolling, and the average values ​​can be measured. In addition, one embodiment of the present invention also has excellent mechanical strength. More specifically, the yield strength may be 480 MPa or more and 570 MPa or less. The yield strength can be measured using the 0.2% off-set method during a tensile test. A method for manufacturing a non-oriented electrical steel sheet according to one embodiment of the present invention includes a step of hot-rolling a slab to manufacture a hot-rolled steel sheet; a step of cold-rolling the hot-rolled steel sheet to manufacture a cold-rolled sheet; and a cold-rolled sheet annealing step of annealing the cold-rolled sheet. Below, each step is explained in detail. First, the slab is hot rolled. Since the alloy composition of the slab has been described in the alloy composition of the non-oriented electrical steel sheet mentioned above, a duplicate description will be omitted. Since the alloy composition does not substantially change during the manufacturing process of the non-oriented electrical steel sheet, the alloy composition of the non-oriented electrical steel sheet and the slab are substantially the same. Specifically, the slab contains Si: 1.5 to 5.0% by weight, Al: 0.1 to 2.5%, Mn: 0.1 to 2.5%, and the remainder includes Fe and inevitable impurities. As for other additional elements, they have been described in the alloy composition of non-oriented electrical steel sheets, so any duplicate description will be omitted. The slab can be heated before hot rolling. The heating temperature of the slab is not limited, but the slab can be heated to 1200℃ or lower. If the slab heating temperature is too high, precipitates such as AlN and MnS present in the slab may be re-dissolved and then finely precipitated during hot rolling and annealing, which may inhibit grain growth and reduce magnetism. Next, the slab is hot rolled to produce a hot-rolled plate. In one embodiment of the present invention, it was found that in order to improve the aggregate structure, it is necessary to precisely control the conditions from the hot rolling stage. Specifically, it was found that it is necessary to control the reduction ratio of each pass in the rolling. In one embodiment of the present invention, the step of manufacturing a hot rolled steel sheet includes a rough rolling step and a finish rolling step. The rough rolling step is a process of first rolling a slab moved from a casting machine into a steel sheet shape to manufacture a bar, and is composed of about 3 to 4 rolling mills, and the finish rolling is a process of rolling a rough rolled steel sheet (bar) into a final hot rolled target thickness to make a hot rolled coil, and is composed of a continuous multi-stage rolling mill. The thought rolling step is performed through n passes, where n is 2 or more, and satisfies Equation 3. [Formula 3] R1 / (R1+R2+……+Rn) ≥ 0.20 (In Equation 3, R1 to Rn represent the pressure reduction ratios (%) of the 1st to nth passes, respectively.) In one embodiment of the present invention, since the reduction ratio and the first reduction ratio of each step of the rolling process have a significantly large effect on the formation of the grain structure, if the reduction ratio of each pass is appropriately adjusted as in Equation 3, the α-fiber and γ-fiber grain structures can be weakened, thereby improving the magnetism. R1 means the first pass, and the number of passes can be based on passing through the work roll. In addition, the nth pass is the last pass, and R1+R2+… …+Rn means the sum of the reduction ratios of all passes in the grain rolling process. The reduction ratio can be obtained by (steel sheet thickness before the pass - steel sheet thickness after the pass) / (steel sheet thickness before the pass) × 100(%). In one embodiment of the present invention, the rolling process may be performed in 3 to 7 passes (i.e., n is 3 to 7). If the number of passes is too small, the rolling load may be too large, making the work difficult. If the number of passes is too large, productivity may be reduced. If the reduction ratio R1 of the first pass of the rolling process is too large to satisfy Equation 3, the γ-fiber may be greatly strengthened, resulting in poor magnetism. More specifically, the value of Equation 3 may be between 0.21 and 0.45. The thought rolling step can satisfy the following equation 4. [Formula 4] R1 / Rn ≤ 8.0 (In Equation 4, R1 and Rn represent the pressure reduction ratios (%) of the 1st and nth passes, respectively.) If the reduction ratio Rn of the last pass of the rolling process is too small to satisfy Equation 4, the improvement effect of the magnetization-friendly directions (001)[0-10], (001)[-1-10], (100)

[0025] may not be sufficient. More specifically, the value of Equation 4 may be 1.5 to 7.5. The first pass reduction ratio (R1) in the rolling process can be 35 to 80%, more specifically 38 to 80%. The reduction ratio (Rn) of the last pass in the rolling process can be 7 to 35%, more specifically 10 to 30%. The hot rolled sheet may have a thickness of 1.0 to 4.5 mm. The finishing rolling temperature in the step of manufacturing the hot rolled sheet may be 800°C or higher. Specifically, it may be 800 to 1000°C. The hot rolled sheet may be coiled at a temperature of 700°C or lower. More specifically, the thickness of the hot rolled sheet may be 1.5 to 4.3 mm. After manufacturing the hot-rolled steel plate, a step of annealing the hot-rolled plate may be further included. At this time, the soaking temperature may be 850 to 1100°C. If the annealing temperature is too low, the recrystallized structure may not be formed or may grow finely, so that the effect of increasing the magnetic flux density is small. If the annealing temperature is too high, the magnetic properties may rather deteriorate, and the rolling workability may deteriorate due to deformation of the plate shape. More specifically, the temperature range may be 830 to 1080°C. The soaking time may be 10 to 300 seconds. The hot-rolled plate annealing step may be omitted. Next, the hot rolled steel sheet is cold rolled to manufacture a cold rolled sheet. At this time, cold rolling can be performed at a reduction ratio of 40 to 85%. If the reduction ratio is too low, the accumulated strain energy in the rolled steel sheet is small, making it difficult to recrystallize in the subsequent annealing process, so that the rolled structure remains, which can cause problems in improving the magnetic flux density and iron loss. On the other hand, if the reduction ratio is too high, it can cause problems in the subsequent annealing process. <111> / ND The problem may occur that recrystallization of the orientation grains is promoted and the grains become finer, resulting in inferior magnetic flux density and increased iron loss. More specifically, the reduction ratio may be 60 to 75%. The cold rolling step may use a Tandem cold rolling mill that continuously cold-rolls the steel sheet using a plurality of rolling stands, or a Reverse rolling mill that discontinuously cold-rolls the steel sheet using 12 or more rolling rolls. The final rolled thickness may be 0.1 mm to 0.35 mm. The step of manufacturing cold rolled sheet can be performed once or twice or more with intermediate annealing in between. Next, the cold rolled sheet is annealed in the cold rolled sheet annealing step. In the process of annealing the cold rolled sheet, the annealing temperature is not particularly limited as long as it is a temperature that is usually applied to non-oriented electrical steel sheets. The iron loss of non-oriented electrical steel sheets is closely related to the grain size. The iron loss of non-oriented electrical steel sheets can be divided into hysteresis loss and eddy current loss. The hysteresis loss decreases as the grain size increases, and conversely, the eddy current loss increases as the grain size increases. Therefore, there is an optimal grain size at which the sum of the hysteresis loss and the eddy current loss is minimized. Therefore, it is important to derive and apply an annealing temperature that can secure the optimal grain size, and the annealing temperature is appropriate if it is 850 to 1100℃. If the annealing temperature is too low, the grains are too fine, which increases the hysteresis loss, and if it is too high, the grains are too coarse, which increases the eddy current loss, resulting in poor iron loss. Also, the annealing time is appropriate if it is 10 to 300 seconds, and annealing can be performed in a mixed atmosphere of hydrogen or argon and nitrogen to prevent magnetic deterioration due to the formation of an oxide layer. During the cold rolled sheet annealing process, all (i.e., more than 99%) of the processed structures formed during the cold rolling stage can be recrystallized. After cold-rolled sheet annealing, an insulating film can be formed. The insulating film can be treated with an organic, inorganic, or organic-inorganic composite film, and it can also be treated with other insulating film agents. Hereinafter, the present invention will be described in more detail through examples. However, these examples are only for illustrating the present invention, and the present invention is not limited thereto. Example 1 Table 1 and the remainder Fe and unavoidable impurities were included to manufacture a slab. It was heated to 1170℃, hot-rolled to a thickness of 2.2 mm, and then coiled at 680℃. At this time, 7 passes were performed in the sand rolling, and the reduction ratio of each pass was performed as shown in Table 2 below. The hot-rolled steel sheet was hot-rolled at 1000℃ for 50 seconds. After the hot-rolled sheet annealing, the pickled specimen was cold-rolled to a thickness of 0.2 mm, and finally cold-rolled sheet annealing was performed. At this time, the cold-rolled sheet annealing was performed at 1000℃ for 50 seconds. The aggregate structure was analyzed by cutting the steel plate in the rolling direction to obtain a specimen and using EBSD. At this time, the tolerance angle was set to 15°. Yield strength was measured by the 0.2% off-set method during tensile testing. Iron loss (W10 / 400) and magnetic flux density (B50) were measured using a single sheet tester. Steel type SiMnAlCPSTiN Resistivity (μΩ cm) 13.281.452.080.00150.0040.00400.00070.002782.023.642.291.470.00200.0090.00090.00180.002383.933.281.530 .630.00130.0080.00380.00320.003766.143.110.751.070.00110.0130.00140.00290.001864.753.281.812.240.00220.0100.00110.00130.00168 5.963.482.070.630.00140.0090.00140.00150.001571.472.950.821.480.00100.0100.00230.00140.002867.983.810.672.050.00290.0130.0019 0.00200.001483.393.340.560.960.00140.0100.00090.00270.002865.0103.441.291.340.00290.0070.00330.00360.001574.6112.861.501.560. 00240.0070.00360.00240.002271.7123.261.100.990.00110.0090.00270.00180.003767.5133.010.541.640.00260.0120.00130.00130.002868.8 142.742.502.120.00320.0120.00160.00090.002782.3153.551.341.510.00130.0060.00260.00280.002778.0162.410.981.300.00070.0070.0008 0.00270.001260.7172.990.850.450.00370.0030.00190.00150.003456.9183.061.110.700.00080.0070.00270.00210.002162.0193.150.621.320 .00360.0040.00300.00290.002367.3203.720.381.540.00120.0050.00370.00260.001474.8213.830.671.640.00180.0070.00380.00250.004078.8223.061.991.610.00090.0060.00150.00170.001277.3232.620.752.030.00120.0100.00100.00320.002670.0243.901.791.600.00210.0110.00210.00300.003185.5253.301.610.540.00320.0100.00370.00230.001565.7263.711.440.890.00350.0 030.00270.00340.001673.4272.890.671.480.00240.0130.00280.00180.001066.4283.512.050.500.00190.0080.00120.00220.003870.1292.981.030.830.00390.0130.00150.00360.003462.1303.200.500.570.00200.0080.00280.00120.002958.7. SteelR1 (%)R1+R2+…+Rn (%)Rn (%)Formula 3 4173286130.265.6253235290.231.8344209220.212.0436168110.213.3558228250.252.3638100120.383.2771180250.392.8852180140.293.7980324130.256.21042201230.211.81155262160.213.41266221160.304.11366151170.443.91471285100.257.11564286150.224.31 653254130.214.1173813150.297.61836132180.272.01932181240.181.3207120670.3410.1215028860.178.32243238180.182.42328178280.161.0246018650.3212.0256520360.3210.8268025490.318.92732350260.091.2286333670.199.0293820140.199.5304022140.1810.0 Steel Type 1 Yield Strength (MPa) W10 / 400 (W / Kg) B50 (T) Classification 11.090.375 309.121.62 Invention Example 21.370.925 219.201.62 Invention Example 31.150.84485 9.881.63 Invention Example 40.550.88487 10.021.63 Invention Example 51.300.705 309.351.62 Invention Example 60.770.425 179.801.63 Invention Example 70.500.4048 19.771.62 Invention Example 80.651.285239.191.62Invention example90.720.685129.801.63Invention example100.670.355449.651.62Invention example111.180.824989.821.63Invention example121.091.0550410.181.64Invention example131.021.055119.861.63Invention example140.960.925309.501.62Invention example151.290.3854210.131.64 Invention Example 161.200.3741413.151.59Comparative Example 171.060.5742913.211.59Comparative Example 180.890.6045812.531.58Comparative Example 190.850.3350812.551.57Comparative Example 200.380.6549013.101.59Comparative Example 210.200.2350612.981.59Comparative Example 220.430.2952012.801.59Comparative Example 230.380.554 9012.731.58Comparative Example 240.560.3358713.121.59Comparative Example 250.350.3348313.861.57Comparative Example 260.360.4753912.401.58Comparative Example 270.480.2848612.941.58Comparative Example 280.410.2950212.821.58Comparative Example 290.370.3346713.201.59Comparative Example 300.400.2646113.681.58Comparative Example As shown in Tables 1 to 3, No. 1 to 15, which have developed a specific aggregate structure by appropriately controlling the steel composition and rolling reduction ratio, can be confirmed to have excellent iron loss, magnetic flux density, and yield strength at the same time. On the other hand, No. 16 to 30, where the steel composition or process conditions were not properly controlled and a specific aggregate structure was not developed, were found to have inferior iron loss, magnetic flux density, or yield strength. The present invention is not limited to the embodiments, but can be manufactured in various different forms, and a person having ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing the technical idea or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.< / uvw> < / uvw>

Claims

1. Contains Si: 1.5 to 5.0% by weight, Al: 0.1 to 2.5%, and Mn: 0.1 to 2.5%, with the remainder being Fe and inevitable impurities. A non-oriented electrical steel sheet satisfying the following equation 1. [Formula 1] 0.45 ≤ (VA+VB+VC) / (VD+VE+VF) ≤ 1.45 (In Equation 1, VA, VB, VC, VD, VE, and VF represent the area fraction (%) of the aggregate structure having orientations within 15° from (001)[0-10], (001)[-1-10], (100)[025], (223)[1-10], (111)[3-41], and (112)[1-10], respectively.) 2. In paragraph 1, Non-oriented electrical steel sheet satisfying the following equation 2 [Formula 2] 0.35 ≤ VC / VE ≤ 1.35 (In Equation 2, VC and VE represent the area fraction (%) of the aggregate structure having orientations within 15° from (100)[025] and (111)[3-41], respectively.) 3. In paragraph 1, Non-oriented electrical steel sheet further comprising at least one of P: 0.1 wt% or less (excluding 0%), C: 0.005 wt% or less (excluding 0%), S: 0.005 wt% or less (excluding 0%), Ti: 0.005 wt% or less (excluding 0%), and N: 0.005 wt% or less (excluding 0%).

4. In paragraph 1, A non-oriented electrical steel sheet further comprising 0.005 to 0.200 wt% of each or a combined amount of one or more of Sn, Sb, Bi, Pb, Ge and As.

5. In paragraph 1, A non-oriented electrical steel sheet further comprising at least one of Cu: 0.005 to 0.2 wt%, Cr: 0.01 to 0.5 wt%, Ni: 0.05 wt% or less (excluding 0%), Zn: 0.01 wt% or less (excluding 0%), and Co: 0.05 wt% or less (excluding 0%).

6. In paragraph 1, Non-oriented electrical steel sheet further comprising at least one of Mo: 0.03 wt% or less (excluding 0%), B: 0.0050 wt% or less (excluding 0%), V: 0.0050 wt% or less (excluding 0%), Ca: 0.0050 wt% or less (excluding 0%), Nb: 0.0050 wt% or less (excluding 0%), Zr: 0.005 wt% or less (excluding 0%), Te: 0.01 wt% or less (excluding 0%), and Mg: 0.0050 wt% or less (excluding 0%).

7. In paragraph 1, Non-oriented electrical steel sheet having a resistivity (ρ) of 63 μΩ·cm or more at 25℃.

8. In paragraph 1, Non-oriented electrical steel sheet with iron loss (W10 / 400) of 12.0 W / Kg or less and magnetic flux density (B50) of 1.60 T or more. A step of manufacturing a hot-rolled steel sheet by hot-rolling a slab containing Si: 1.5 to 5.0% by weight, Al: 0.1 to 2.5%, and Mn: 0.1 to 2.5% by weight, with the remainder being Fe and unavoidable impurities; A step of manufacturing a cold rolled sheet by cold rolling the hot rolled steel sheet above, and A cold rolled sheet annealing step for annealing the cold rolled sheet; The step of manufacturing the above hot rolled steel plate includes a rough rolling step and a finish rolling step, The above thought rolling step is performed through n passes, where n is 2 or more, A method for manufacturing a non-oriented electrical steel sheet satisfying the following equation 3. [Formula 3] R1 / (R1+R2+……+Rn) ≥ 0.2 (In Equation 3, R1 to Rn represent the pressure reduction ratios (%) of the 1st to nth passes, respectively.) 10. In paragraph 9, The above-mentioned rolling step is a method for manufacturing a non-oriented electrical steel sheet satisfying the following equation 4. [Formula 4] R1 / Rn ≤ 8 (In Equation 4, R1 and Rn represent the pressure reduction ratios (%) of the 1st and nth passes, respectively.) 11. In paragraph 9, A method for manufacturing a non-oriented electrical steel sheet having a first pass reduction ratio (R1) of 35 to 80% in a continuous rolling process.

12. In paragraph 9, A method for manufacturing a non-oriented electrical steel sheet having a reduction ratio (Rn) of 7 to 35% in the last pass of the continuous rolling process.

13. In paragraph 9, A method for manufacturing a non-oriented electrical steel sheet, wherein the above slab further includes at least one of P: 0.1 wt% or less (excluding 0%), C: 0.005 wt% or less (excluding 0%), S: 0.005 wt% or less (excluding 0%), Ti: 0.005 wt% or less (excluding 0%), and N: 0.005 wt% or less (excluding 0%).

14. In paragraph 9, A method for manufacturing a non-oriented electrical steel sheet, wherein the above slab further contains 0.005 to 0.200 wt% of each or a combined amount of one or more of Sn, Sb, Bi, Pb, Ge and As.

15. In paragraph 9, A method for manufacturing a non-oriented electrical steel sheet, wherein the above slab further includes at least one of Cu: 0.005 to 0.2 wt%, Cr: 0.01 to 0.5 wt%, Ni: 0.05 wt% or less (excluding 0%), Zn: 0.01 wt% or less (excluding 0%), and Co: 0.05 wt% or less (excluding 0%).

16. In paragraph 9, A method for manufacturing a non-oriented electrical steel sheet, wherein the above slab further includes at least one of Mo: 0.03 wt% or less (excluding 0%), B: 0.0050 wt% or less (excluding 0%), V: 0.0050 wt% or less (excluding 0%), Ca: 0.0050 wt% or less (excluding 0%), Nb: 0.0050 wt% or less (excluding 0%), Zr: 0.005 wt% or less (excluding 0%), Te: 0.01 wt% or less (excluding 0%), and Mg: 0.0050 wt% or less (excluding 0%).