NON-ORIENTED ELECTRICAL STEEL SHEET, MOTOR CORE AND METHODS OF PRODUCTION THEREOF

Abstract

In the production of a non-oriented electrical steel sheet by hot rolling a steel plate containing Si: 2.8 to 6.5% by mass and Zn: 0.0005 to 0.0050% by mass, followed by cold rolling and finish annealing, a coating agent containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb and Bi is applied to the surface of the steel sheet after the finish annealing, to form an insulating coating with nitriding suppression capability.Alternatively, an intermediate layer containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi and having nitriding suppression capability is formed on the iron matrix of the steel sheet after finish annealing, and an insulating coating not containing the above elements is formed on the intermediate layer to thus obtain an electrically non-oriented steel sheet from which a rotor core with high strength and a stator core with excellent magnetic properties can be obtained simultaneously after stress-relief annealing, and a motor core comprising a stator core and a rotor core is produced from the steel sheet.

Description

NON-ORIENTED ELECTRICAL STEEL SHEET, MOTOR CORE AND METHODS OF PRODUCTION THEREOF TECHNICAL FIELD This invention relates to an electrically non-oriented steel sheet and motor core, preferably used for an iron core of a small, high-performance motor, as well as methods for producing the electrically non-oriented steel sheet and motor core. PREVIOUS TECHNIQUE With the increasing demand for energy efficiency in electrical equipment in recent years, it has become necessary for the non-oriented electrical steel laminations used in the iron core of a rotating device (motor core) to have superior magnetic properties compared to conventional laminations. In particular, a drive motor for a hybrid electric vehicle (HEV) needs to be smaller and have a higher power output, thus requiring that the non-oriented electrical steel laminations used as the core material for these motors possess superior magnetic properties (higher magnetic flux density and lower iron loss). A motor core comprises a fixed stator core and a rotating rotor core. The revolutions per minute (RPM) of an HEV-driven motor tend to increase to achieve a smaller size and higher power output. Therefore, a large centrifugal force is applied to the rotor core, which has a large outer diameter. Furthermore, the rotor core has a very narrow portion (1 to 2 mm) called the bridge portion, depending on its structure. Consequently, it is essential that the non-oriented electrical steel lamination used in the rotor core of an HEV-driven motor have higher strength than conventional laminations. The non-oriented electrical steel lamination used in the core of a high-energy electric motor (HEV) is desired to have excellent magnetic properties. Furthermore, it is desired to have high strength for use in the rotor core, while having higher magnetic flux density and lower iron loss for use in the stator core. Therefore, the rotor core and stator core are required to have significantly different characteristics, even within the same motor core. Meanwhile, it is desirable to extract the rotor core and stator core material from the same steel lamination source simultaneously to increase material yield and reduce material inventory during motor core production. As the non-oriented electrical steel sheet has high strength and excellent magnetic properties as described above, for example, Patent Literature 1 proposes a method for producing a motor core comprising extracting, by cutting, the rotor core material and the stator core material from a non-oriented electrical steel sheet having a thickness Rcconn / zznz / E / YiAi of 0.15 to 0.35 mm sheet and a yield strength before stress relief annealing of not less than 600 MPa at the same time, roll the respective materials to assemble a rotor core and a stator core, and subsequently subject only the stator core to stress relief annealing, so that the motor core has an iron loss W10 / 400 of not more than 20 W / kg after stress relief annealing. APPOINTMENT LIST Patent Literature Patent Literature 1: JP-A-2008-50686 BRIEF DESCRIPTION OF THE INVENTION Technical Problem However, in the technique disclosed in Patent Literature 1, an expensive element, Ni, is added at no less than 0.5% by mass to increase the strength of the steel sheet, causing a problem of high production costs. Furthermore, when the steel sheet disclosed in Patent Literature 1 is subjected to stress-relief annealing, the magnetic properties, especially the iron loss properties, deteriorate, causing a significant decrease in motor efficiency. The invention is made taking into account the above problems and aims to provide a non-oriented electrical steel sheet from which a rotor core with high strength and a stator core with excellent magnetic properties can be extracted at the same time after stress-relief annealing without using expensive Ni and a motor core made from the non-oriented electrical steel sheet, and also to propose methods for producing the non-oriented electrical steel sheet and the motor. Solution to the problem To solve the aforementioned problems, especially to prevent the deterioration of magnetic properties after stress-relief annealing, the inventors conducted several studies focusing on the influence of surface characteristics on the magnetic properties of non-oriented electrical steel sheet. As a result, the inventors discovered that the deterioration of magnetic properties caused by stress-relief annealing results from nitriding in the surface layer of the steel sheet during the stress-relief annealing process, and that, in order to suppress nitriding in the surface layer of the steel sheet, it is effective for a steel material (plate) to contain Rccann / zznz / E / YiAi a prescribed amount of Zn and that a coating has a suitable capacity to suppress nitriding on the surface of steel sheet prior to stress relief annealing, resulting in the development of the invention. That is, the present invention is a non-oriented electrical steel sheet having a component composition comprising: C: not more than 0.0050% by mass, Si: 2.8 to 6.5% by mass, Mn: 0.1 to 2.0% by mass, P: not more than 0.10% by mass, S: not more than 0.0050% by mass, Al: 0.3 to 2.0% by mass, N: not more than 0.0050% by mass, Zn: 0.0005 to 0.0050% by mass, Ti: not more than 0.0030% by mass, Nb: not more than 0.0030% by mass, O: not more than 0.0050% by mass, the remainder being Fe and unavoidable impurities, and having a coating layer containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb and Bi on the surface of the steel sheet. The non-oriented electrical steel sheet according to the present invention is characterized by containing, in addition to the component composition described above, at least one composition group selected from the following groups A to D: Group A: one or two selected from Sn: 0.005 to 0.20% by mass and Sb: 0.005 to 0.20% by mass; Group B: one or two or more selected from Ca, Mg and REM between 0.0005 and 0.020% by mass in total; Group C: one or two or more selected from Cu, Ni, Cr and Co in 0.01 to 1.0% by mass in total; and Group D: one or two selected from Mo: 0.001 to 0.1% by mass and W: 0.001 to 0.1% by mass. The coating layer of the non-oriented electrical steel sheet according to the invention is an insulating coating formed on the surface of the iron matrix of the steel sheet. The coating layer of the non-oriented electrical steel sheet according to the invention includes an insulating coating formed in an upper layer on the surface of the steel sheet and an intermediate layer formed between the insulating layer and the iron matrix surface of the steel sheet. The intermediate layer contains at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi. The invention proposes a method for producing a non-oriented electrical steel sheet comprising subjecting a steel plate to hot rolling, cold rolling, and finish annealing, wherein the steel plate has a component composition comprising C: not more than 0.0050% by mass, Si: 2.8 to 6.5% by mass, Mn: 0.1 to 2.0% by mass, P: not more than 0.10% by mass, S: not Rccann / zznz / E / YiAi more than 0.0050% by mass, Al: 0.3 to 2.0% by mass, N: not more than 0.0050% by mass, Zn: 0.0005 to 0.0050% by mass, Ti: not more than 0.0030% by mass, Nb: not more than 0.0030% by mass, O: not more than 0.0050% by mass, the remainder being Fe and unavoidable impurities, and a coating layer containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb and Bi is formed on the surface of the steel sheet after the finish annealing. The steel plate used in the method for producing an electrically oriented steel sheet is characterized by containing at least one composition group selected from the following groups A to D: Group A: one or two selected from Sn: 0.005 to 0.20% by mass and Sb: 0.005 to 0.20% by mass; Group B: one or two or more selected from Ca, Mg and REM between 0.0005 and 0.020% by mass in total; Group C: one or two or more selected from Cr, Co, Ni and Cu in 0.01 to 1.0% by mass in total; and Group D: one or two selected from Mo: 0.001 to 0.1% by mass and W: 0.001 to 0.1% by mass. The method for producing a non-oriented electrical steel sheet is characterized by applying a coating agent containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb and Bi to the iron matrix surface of the steel sheet after finish annealing to thus form, as the coating layer, an insulating coating with nitriding suppression capability. The method for producing a non-oriented electrical steel sheet is characterized by applying a treatment agent containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi to the iron matrix surface of the steel sheet after finish annealing to form, as the coating layer, an intermediate layer with nitriding suppression capability and to form an insulating coating that does not contain the elements described above in the intermediate layer. The invention is a motor comprising a rotor core formed by laminating core material processed from any of the aforementioned non-oriented electrical steel sheets into a core shape and a stator core formed by laminating core material processed from the same non-oriented electrical steel sheet as the former into a core shape and performing a stress-relief annealing thereon, wherein Rccann / zznz / E / YiAi The steel sheet that makes up the stator core has an iron loss Ww / soo (W / kg) that satisfies the following equation (1) with respect to the sheet thickness t (mm): W10 / 800 2 15 + 80xt.....(1) and The N present as AIN (N as AIN) in a layer from a lateral surface to 1 / 20 of the thickness of the steel sheet after stress relief annealing is not greater than 0.0100% by mass. The present invention proposes a method for producing a motor core comprising a stator core and a rotor core, comprising processing a non-oriented electrical steel sheet produced by any of the methods described above into a core shape, rolling the core-shaped material to assemble a stator core and a rotor core, subjecting the stator core to stress-relief annealing, wherein the stress-relief annealing is performed under an atmosphere comprising a gas selected from nitrogen, hydrogen, and rare gas, or a mixture of two or more of the gases, at an immersion temperature of 800 to 950°C for an immersion time of 0.5 to 3.0 h. The method for producing an engine core according to the invention is characterized in that the steel sheet after stress-relief annealing has an iron loss W10 / 800 (W / kg) that satisfies the following equation (1) with respect to the sheet thickness t (mm): W10 / 800 < 15 + 80xt.....(1) and The N present as AIN (N as AIN) in a layer from a lateral surface to 1 / 20 of the thickness of the steel sheet after stress relief annealing is not greater than 0.0100% by mass. Favorable Effects of the Invention The present invention is capable of producing a rotor core with high strength and a stator core with low iron loss after stress-relief annealing from the same sheet steel material. Therefore, the electrically non-oriented sheet steel produced according to the present invention can greatly contribute to size reduction and increased output efficiency of motors used in HEVs, electric cars, vacuum cleaners, high-speed generators, air compressors, mechanical tools, etc. BRIEF DESCRIPTION OF THE DRAWINGS Figures 1(a) and 1(b) are graphs showing the variations in W10 / 800 iron loss after stress-relief annealing and a concentration of N in a layer 1 / 20 of the thickness of the steel sheet at different draw loads. Rcconn / zznz / E / YiAi Figure 2 is a graph showing a relationship between the Zn content of the steel material and the iron loss W-io / soo after stress-relief annealing. Figure 3 is a graph showing a relationship between a concentration of N in a layer 1 / 20 of the thickness of the steel sheet and a loss of iron W10 / 800 after stress relief annealing. Figure 4 is a view showing an example of the relationship between sheet thickness and iron loss W10 / 800. DESCRIPTION OF THE MODALITIES One embodiment of the present invention will be described in detail below. First Modality The first embodiment of the present invention is characterized in that a steel material (plate) contains a suitable amount of Zn to form a coating consisting of a compound such as an oxide containing Zn or Al on the surface of the steel sheet after finish annealing, and an insulating coating containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi is formed on the surface of the steel sheet after finish annealing to apply a nitriding suppression capability to both coatings, suppressing nitriding of the surface of the steel sheet in stress-relief annealing. First, an experiment that has led to the development of the first modality of the invention will be explained below. Experiment 1 Two charges (Charges A and B) of steel having a component composition comprising C: 0.0025% by mass, Si: 3.5% by mass, Mn: 0.6% by mass, P: 0.01% by mass, S: 0.0015% by mass, Al: 0.9% by mass, N: 0.0023% by mass, Ti: 0.0011% by mass, Nb: 0.0009% by mass, O: 0.0021% by mass and the remainder being Fe and unavoidable impurities are melted to form steel material (plate) by the continuous casting method. The slab is hot-rolled to form a 1.9 mm thick hot-rolled sheet, hot-annealed at 950°C for 30 seconds, pickled, and cold-rolled to form a final 0.30 mm thick cold-rolled sheet. The cold-rolled sheet is then finished annealed at 800°C for 10 seconds under a 20:80 H₂:N₂ atmosphere by volume.An insulating coating is formed on the front and back faces of the steel sheet after the final annealing to create a finished product sheet. Note that the insulation is coated by mixing monomagnesium phosphate: Mg(H2PO4)2 (manufactured by Taihei Chemical Industrial Co., Ltd.) and acrylic resin (EFD-5560 manufactured by DIC Corporation). Rccann / zznz / E / YiAi a solid content ratio of 90:10 by mass%, adjusting the solid content concentration of the mixture to 10% by mass using deionized water to form an application liquid, applying the application liquid to both sides of the steel sheet by means of a roller coater, so that the coating on each side has a coating weight of 0.5 g / m2 after baking, and baking the steel sheet in a hot air oven with the condition that the maximum sheet temperature of 280°C is reached in 30 seconds (the immersion temperature is 0 seconds). Next, test samples 280 mm long and 30 mm wide are cut in the rolling direction (L direction) and in the direction (C direction) perpendicular to the rolling direction from a sheet of product coated with the insulating coating. These samples are then subjected to a heat treatment simulating stress-relief annealing at 850°C for 1 hour in a 100% vol. N2 atmosphere. The high-frequency iron loss (Ww / eoo) is then measured in the (L+C) direction using the Epstein test. The results show variations in the iron loss measurement values, and as shown in Figure 1(a), the iron loss after stress-relief annealing for a specific load (Load B) is excellent.In order to examine the cause of this, the concentration of N (N as AlN) present as AlN in the surface layer of the steel sheet is examined, specifically within the layer from the surface on one side to 1 / 20 of the steel sheet thickness (hereafter, the layer from the surface on one side to 1 / 20 of the steel sheet thickness is simply referred to as the 1 / 20 sheet thickness layer). The result shows that, as indicated in Figure 1(b), nitriding occurs in the surface layer of the steel sheet from Load A with a high iron loss, while the concentration of N in the surface layer of the steel sheet from Load B with a low iron loss differs little from the extraction value, and nitriding is suppressed. Consequently, trace components in the raw steel material are analyzed further, revealing that Zn is present at approximately 0.0020% by mass in the raw steel material of Load B. Experiment 2 An experiment is performed to examine the influence of Zn content on the nitriding behavior on the surface of the steel sheet in stress relief annealing and the iron loss properties after stress relief annealing as follows. Steel with a component composition comprising C: 0.0027% by mass, Si: 3.6% by mass, Mn: 0.8% by mass, P: 0.01% by mass, S: 0.0018% by mass, Al: 1.1% by mass, N: 0.0021% by mass, Ti: 0.0012% by mass, Nb: 0.0008% by mass, O: 0.0022% by mass, Zn: an amount ranging from 0.0001 to 0.01% by mass, the remainder being Fe and unavoidable impurities, is melted in a vacuum melting furnace, cast into a steel ingot, and hot-rolled to form a hot-rolled sheet with a sheet thickness of 2.0 mm. The hot-rolled sheet is then subjected to Rcconn / zznz / E / YiAi hot-band annealed at 940°C for 30 seconds, pickled, cold-rolled to form a cold-rolled sheet with a final sheet thickness of 0.25 mm. The cold-rolled sheet is subjected to a final annealing at 780°C for 10 seconds in an H2:N2 atmosphere in a % vol. ratio of 20:80 and coated with an insulating coating on the front and back faces of the steel sheet under the same conditions as in Experiment 1 to thus produce a product sheet. Next, test samples with a length of 280 mm and a width of 30 mm are cut from the rolling direction (L direction) and the direction (C direction) perpendicular to the rolling direction of the product sheet coated with the insulating coating. These samples are then subjected to a heat treatment simulating stress-relief annealing at 830°C for 1 hour in a 100% N2 by volume atmosphere. The high-frequency iron loss W10 / 800 in the (L+C) direction is then measured using the Epstein test, the results of which are shown in Figure 2. As can be seen in Figure 2, the iron loss value after stress-relief annealing decreases when the Zn content is within a predetermined range. In particular, when the Zn content is in the range of 0.0005 to 0.005% by mass, the iron loss value is lower than the reference iron loss value defined by the following formula (2): W10 / 800 = 15 + 80> <t ...(2). The iron loss reference value defined by formula (2) is the upper limit of the iron loss Wio / soo considered necessary to reduce the heat generated in the stator core and prevent a decrease in motor efficiency. The iron loss value depends largely on the lamination thickness, and as shown in Figure 4, eddy current loss increases with increasing lamination thickness, even for steel laminations with identical properties. Therefore, in the present invention, the iron loss reference value is determined by formula (2) with respect to the lamination thickness. Note that Figure 4 illustrates the relationship between lamination thickness and iron loss for an inventive example, which will be described later in the Example. To examine the cause of the decrease in iron loss due to the addition of Zn, a cross-section of the steel sheet thickness after stress-relief annealing was observed using a scanning electron microscope (SEM). The results show that in the steel sheet with an iron loss value higher than the reference iron loss value, a large amount of finely precipitated AlN is observed in the surface layer, specifically the layer extending from the surface on one side to 1 / 20 of the sheet thickness. This suggests that the finely precipitated nitride may be causing the increased iron loss. Furthermore, the insulating coating is removed from the steel sheet after stress-relief annealing, and the concentration of N (N as N₂) present as N₂ in the 1 / 20-thick layer of the sheet is then analyzed using the electrolytic extraction method. Figure 3 shows the relationship Rcconn / zznz / E / YiAi between the concentration of N and the iron loss Ww / soo. As can be seen in Figure 3, the steel sheet manufactured from steel material with Zn added at a suitable interval has the concentration of N present as Al in the 1 / 20 thickness layer of the sheet of no more than 100 ppm by mass (0.0100% by mass). The reason why the addition of Zn to the steel raw material suppresses nitriding in stress-relief annealing is considered to be that a coating formed on the surface of the steel sheet in stress-relief annealing consists of compounds such as oxides containing, for example, Zn, Al, or similar elements. In the invention, therefore, it is an essential requirement that the concentration of N within the 1 / 20 thickness layer of the steel sheet after stress-relief annealing not exceed 0.0100% by mass. The inventors then studied a method for suppressing nitriding on the surface of steel sheet during stress-relief annealing, distinct from the method of adding Zn to the steel raw material. As a result, they discovered that including at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and B1 in the insulating coating that will form on the surface of the steel sheet before stress-relief annealing enables the insulating coating to possess nitriding-suppression capabilities. Specifically, including the aforementioned element(s) in the insulating coating or in mixtures containing the element(s) improves the density and adhesiveness of the insulating coating, resulting in a significant improvement in its nitriding-suppression capabilities. Stress-relief annealing, particularly stress-relief annealing performed at a high immersion temperature of at least 800°C, is expected to improve iron loss properties by relieving processing stress and lubricating the crystal grains. However, it can cause nitriding on the surface layer of the steel sheet and impair its magnetic properties. To address this, adding an appropriate amount of zinc to the steel raw material (sheet) and incorporating a nitriding inhibitor into the insulating coating can more effectively suppress nitriding during stress-relief annealing.In other words, it has been discovered that the addition of Zn to the steel material and the addition of the element that has a nitriding suppressive effect to the insulating coating to suppress nitriding in stress relief annealing are not sufficient when used alone, and the nitriding suppressive effect can be further increased when both are adopted. Second Modality As described above, the first embodiment of the present invention is characterized by including a suitable amount of Zn in the steel material and also by including an element that has a nitriding suppressive effect on the insulating coating, i.e., by imparting a nitriding suppressive capability to the insulating coating so as to suppress nitriding in the layer Rccann / zznz / E / YiAi surface of the steel sheet in stress relief annealing. Meanwhile, the second embodiment of the present invention is characterized by forming, instead of the insulating coating of the first embodiment, an intermediate layer containing an element having a nitriding suppressive effect between the insulating coating and an iron matrix surface of the steel sheet (hence the insulating coating does not contain any element having a nitriding suppressive effect), thereby suppressing nitriding on the surface layer of the steel sheet in stress relief annealing at an elevated temperature. The inventors fabricated a product sheet by immersing the steel sheet, after the final annealing produced in Experiment 1, in a zinc phosphate treatment bath (PB-L47 manufactured by Nihon Parkerizing Co., Ltd.) for 30 seconds, washing it with water, drying it with hot air, forming an intermediate layer on the front and back faces of the steel sheet, and then applying an insulating coating over the intermediate layer. The weight of the intermediate layer coating is determined so that the coating thickness on one side is 30 nm.The insulating coating is formed by mixing silica sol (ST-C manufactured by Nissan Chemical Corporation) and acrylic resin (EFD-5560 manufactured by DIC Corporation) to have a solid content ratio of 90:10% by mass, adjusting the solid content concentration of the mixture to 10% by mass using deionized water to form an application liquid, applying the application liquid to both sides of the steel sheet by means of a roller coater so that the coating weight on each side is 0.5 g / m2, and baking the steel sheet in a hot air oven with the condition that the maximum sheet temperature of 280°C is reached in 30 seconds (the immersion temperature is 0 seconds). Next, test samples with a length of 280 mm and a width of 30 mm are cut in the rolling direction (L direction) and in the direction (C direction) perpendicular to the rolling direction of the product sheet coated with the insulating coating. These samples are then subjected to a heat treatment simulating stress-relief annealing at 830°C for 1 hour in an atmosphere of 100% N₂ by volume. The high-frequency W10 / 800 iron loss is then measured in the (L+C) direction using the Epstein test. As shown in Figure 2 from Experiment 2, the iron loss value decreases when the Zn content is in the range of 0.0005 to 0.005% by mass, and the iron loss value is lower than the reference iron loss value. The insulating coating is removed from the surface of the steel sheet after stress-relief annealing, where the concentration of N (N as AlN) present as AlN in the 1 / 20 sheet thickness layer is analyzed by the electrolytic extraction method. The result shows that, as in Figure 4, all steel sheets with an iron loss W10 / 800 not exceeding the reference value have an N as AlN not exceeding 100 ppm by mass (0.0100% by mass). As can be seen from these results, the formation of the intermediate layer containing the Rccann / zznz / E / YiAi less one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb and Bi, each of which has a nitriding suppressive effect, between the iron matrix surface of the steel sheet and the insulating coating can provide the same nitriding suppressive effect as that caused by the inclusion of the element or elements having a nitriding suppressive effect in the insulating coating. In the second method, since the intermediate layer has nitriding suppression capabilities, it is possible to provide the insulating coating with an insulating or similar effect other than nitriding suppression. Although it is necessary to reinforce the bond of the insulating coating itself to improve its adhesion and scratch resistance, the bond tends to weaken when the coating contains a large number of elements, as in the first method. In the second method, however, the insulating coating does not need to have such a novel function as nitriding suppression, and it is possible to limit the number of elements contained in the coating, thus maintaining the coating's strong bond. In the second mode, the coating layer on the surface of the steel sheet has a multi-layer structure composed of the insulating coating and the intermediate layer formed between the iron matrix surface of the steel sheet and the insulating coating. This can result in a secondary effect of improved corrosion and moisture resistance. Furthermore, the intermediate layer is expected to have an insulating effect in addition to suppressing nitriding. Therefore, the total thickness of the intermediate and insulating coatings can be thinner than the thickness of the insulating coating alone in the first mode. Consequently, the intermediate layer increases the rolling factor (magnetic flux density of the core). The composition of the components of a steel raw material (plate) used to produce a non-oriented electrical steel sheet according to the invention will be explained. There is no difference in the composition of the steel raw material used between the first and second embodiments of the invention. C: no more than 0.0050% by mass Carbon (C) content in steel product sheets is a harmful element that forms carbide, causing magnetic aging and impairing iron loss properties. Therefore, the upper limit for C content in steelmaking raw materials is limited to 0.0050% by mass, preferably no more than 0.0040% by mass. The lower limit for C is not specifically defined, but is preferably around 0.0001% by mass to minimize decarburization costs in the steelmaking process. Yes: 2.8 to 6.5% by mass Silicon has the effect of increasing a specific strength of steel to reduce iron loss and also has the effect of increasing the strength of steel by strengthening the Rcconn / zznz / E / YiAi solid solution, and therefore contains no less than 2.8% by mass. On the other hand, a Si content exceeding 6.5% by mass causes embrittlement of the steel, hindering rolling; therefore, the upper limit for Si is set at 6.5% by mass. It is preferable for the Si content to be within the range of 3.0 to 6.0% by mass. Mn: 0.1 to 2.0% by mass Like silicon, manganese (Mn) is a useful element for increasing the specific strength and toughness of steel. Mn fixes sulfur to improve hot brittleness and is therefore contained at no less than 0.1% by mass. On the other hand, additions exceeding 2.0% by mass cause cracking of the plate and similar materials and impair workability in steelmaking; therefore, the upper limit is set at 2.0% by mass. Mn is preferably contained in the range of 0.2 to 1.5% by mass. In particular, when Mn is contained at no less than 0.2% by mass, MnS is preferentially formed to prevent the formation of ZnS, thus improving the formation of a coating composed of zinc oxide-containing compounds. Q: no more than 0.10% by mass Phosphorus (P) is an element that increases the specific strength of steel and has a significant effect on reducing eddy current losses. P has a high solid solution strengthening capacity and can therefore be added accordingly. However, excessive addition of P leads to steel brittleness and deterioration of cold-rolling properties; therefore, the upper limit is 0.10% by mass, preferably no more than 0.05% by mass. S: no more than 0.0050% by mass Sulfur (S) is converted to sulfide, forming precipitates or inclusions and impairing the productivity (hot rolling properties) and magnetic properties of the product sheet; therefore, a lower content is preferable. Thus, the upper limit for S content is 0.0050% by mass, preferably no more than 0.0030% by mass. Al: 0.3 to 2.0% by mass Aluminum (Al) has a similar effect to silicon (Si) on increasing the specific strength of steel and reducing iron loss. However, when the Al content exceeds 2.0% by mass, the steel becomes embrittled, making rolling difficult; therefore, the upper limit is 2.0% by mass. Conversely, when the Al content is below 0.3% by mass, a fine nitride forms and precipitates, significantly impairing the iron loss properties; therefore, the lower limit is set at 0.3% by mass. It is preferable for the Al content to be within the range of 0.4 to 1.5% by mass. N: no more than 0.0050% by mass N is an element that forms a nitride which must be precipitated and therefore deteriorates magnetic properties, so the N content is limited to no more than 0.0050% by mass, preferably no more than 0.0040% by mass. Rcconn / zznz / E / YiAi Ti: not more than 0.0030% by mass, Nb: not more than 0.0030% by mass Titanium (Ti) and niobium (Nb) are elements that form fine precipitates, increasing iron loss. When each content exceeds 0.0030% by mass, the adverse effect becomes noticeable; therefore, each upper limit is set at 0.0030% by mass, preferably 0.0020% by mass. Or: no more than 0.0050% by mass Oxygen is an element that forms oxide when it remains as an inclusion in steel and deteriorates magnetic properties, so the oxygen content is limited to no more than 0.0050% by mass, preferably no more than 0.0040% by mass. Zn: 0.0005 to 0.0050% by mass Zinc (Zn) is one of the most important elements of the invention. Because it suppresses nitriding during stress-relief annealing, Zn is contained in an amount not less than 0.0005% by mass. On the other hand, when Zn is added in amounts greater than 0.0050% by mass, sulfide is formed, which increases iron loss. Therefore, the Zn content is limited to no more than 0.0050% by mass. The Zn content is preferably in the range of 0.001 to 0.004% by mass. The steel raw material used in the present invention contains Fe and unavoidable impurities as a remainder apart from the aforementioned component composition and may contain, in addition to the aforementioned component composition, at least one group of components selected from the following Groups A to D: Group A: one or two of Sn: 0.005 to 0.20% by mass and Sb: 0.005 to 0.20% by mass Both tin (Sn) and antimony (Sb) have a recrystallization texture-enhancing effect and improve magnetic flux density and iron-loss properties. To achieve these effects, it is preferable to contain one or two of the elements at no less than 0.005% by mass each. However, an addition greater than 0.20% by mass leads to saturation of the effect. Therefore, when adding one or two of Sn and Sb, each addition should be in the range of 0.005 to 0.20% by mass, more preferably in the range of 0.01 to 0.1% by mass. Group B: one or two or more of Ca, Mg and REM by 0.0005 to 0.020% by mass in total Calcium, magnesium, and REM have a stable sulfide-forming effect and improve grain growth properties in stress-relief annealing. To achieve this effect, it is preferable to add these elements at a total of no less than 0.0005% by mass. On the other hand, when the element or elements are added exceeding 0.020% by mass, the aforementioned effect becomes saturated. Therefore, when one, two, or more of these elements are added, the total addition is preferably in the range of 0.0005 to 0.020% by mass. More preferably, it is in the range of 0.001 to 0.008% by mass. Group C: one or two or more selected from Cu, Ni, Cr and Co in 0.01 to 1.0% by mass in total Rccann / zznz / E / YiAi Copper (Cu), nickel (Ni), chromium (Cr), and cobalt (Co) have specific strength-enhancing effects on steel, reducing iron loss and increasing its strength. To achieve these effects, it is preferable to add one or two or more of these elements, selected from Cu, Ni, Cr, and Co, in a total proportion of no less than 0.01% by mass. However, additions exceeding 1% by mass increase costs. Therefore, when adding one or two or more of these elements, the proportion should preferably be between 0.01% and 1.0% by mass, and more preferably between 0.1% and 0.5% by mass. Group D: one or two selected from Mo: 0.001 to 0.1% by mass and W: 0.001 to 0.1% by mass Molybdenum (Mo) and tungsten (W) are effective elements for suppressing surface defects (scaling). Since the steel sheet of the present invention is a high-alloy steel and readily oxidizes on the surface, there is a concern that scaling will occur as a result of surface cracking. However, cracking can be suppressed by adding a minimal amount of Mo and W, which are elements that increase high-temperature strength. This effect is insufficient when the Mo and W content is less than 0.001% by mass, while it becomes saturated with additions exceeding 0.1% by mass, which only leads to increased raw material costs. Therefore, when adding at least one of Mo and W, it is preferable that the content of each be within the aforementioned range. More preferably, each content is in the range of 0.0050 to 0.050% by mass. A method for producing an electrically non-oriented steel sheet in accordance with the invention will now be described. An electrically non-oriented steel sheet according to the invention can be produced by a series of processes comprising: producing a steel raw material (plate) with the component composition described above; hot rolling the plate to form a hot-rolled sheet; subjecting the hot-rolled sheet to a hot-strip annealing step as required; cold rolling the sheet to form a cold-rolled sheet of a final thickness (product sheet thickness); performing a finish annealing on the cold-rolled sheet; and forming an insulating coating thereon. Note that it is the process of forming an insulating coating on the steel sheet after the finish annealing that differs between the first and second embodiments of the present invention. The details will be described below. The steel raw material (plate) used in the production of a non-oriented electrical steel sheet according to the invention can be produced by melting steel having the aforementioned component composition according to the invention by a well-known refining process using a converter, an electric furnace, a vacuum degassing device, or the like, and then by performing a conventional method such as a continuous casting method or an ingot-making method. Note that a thin plate with a thickness not exceeding 100 mm Rcconn / zznz / E / YiAi can be produced by a direct casting method. The slab is then hot-rolled to obtain a hot-rolled sheet using a well-established process. The slab is typically reheated to a specific temperature in a heating furnace before hot-rolling, but it can also be hot-rolled immediately after casting without reheating. If a thin slab is used, it can either be hot-rolled or proceed directly to the next step without hot-rolling. It is preferable that hot strip annealing following hot rolling be performed at an immersion temperature between 800 and 1100°C. When the immersion temperature is below 800°C, the effect of hot strip annealing is too small to achieve a sufficient improvement in magnetic properties. On the other hand, when it exceeds 1100°C, the crystal grains become oily, promoting brittle fracture (sheet breakage) during cold rolling or becoming a disadvantage in terms of production costs. Ideally, the immersion time should not exceed 3 minutes to ensure productivity. Even better, an immersion temperature of 850 to 1000°C and an immersion time of no more than 1 minute are preferable. Hot-rolled steel sheet, or hot-annealed steel sheet, is subjected to one or more cold rolls with an intermediate annealing between each roll to form a cold-rolled sheet of a specified final thickness. The final thickness (final sheet thickness) in cold rolling is not specifically limited, but is preferably in the range of 0.10 to 0.35 mm. When the final sheet thickness is less than 0.10 mm, productivity decreases. Conversely, when it exceeds 0.35 mm, iron loss increases, as shown in Figure 4. Next, the cold-rolled sheet, now of the final thickness, undergoes a final annealing process. This final annealing is preferably continuous immersion annealing at a temperature of 700 to 900°C for 1 to 300 seconds. When the immersion temperature is below 700°C, recrystallization does not progress sufficiently, preventing the achievement of good magnetic properties and a sufficient form correction effect during continuous annealing. Conversely, when the immersion temperature exceeds 900°C, the crystal grain size increases, reducing the strength of the steel sheet. To ensure the required strength after the final annealing of a rotor core, it is desirable to perform the final annealing at a lower temperature for a shorter time, as far as possible while still allowing for form correction. A coating agent that will be an insulating coating is finally applied to at least one side surface of the steel sheet subjected to a finishing annealing, heated and baked to form the insulating coating on it, thereby producing a product sheet. Rcconn / zznz / E / YiAi The insulating coating is not specifically limited to one type, but it preferably contains an inorganic material, or an organic resin and an inorganic material as solid content. The inorganic material ensures weldability and heat resistance, while the organic resin improves conformability by pressing; therefore, it is preferable to select either one depending on the application. Furthermore, if organic resin is included in the insulating coating, the ratio of organic resin to solid content after baking should preferably not exceed 70% by mass. This is because an organic resin content exceeding 70% by mass leads to a deterioration of heat resistance. The organic resin is not particularly limited to a specific type and may preferably be a well-known, conventionally used resin, such as acrylic resin, alkyd resin, styrene resin, polyolefin resin, epoxy resin, phenol resin, urethane resin, polyester resin, or melamine resin. The inorganic material is also not particularly limited to a specific type and may be selected from one or more oxides, hydroxides, carbonates, carbides, or similar compounds of Si, Al, Ti, Zr, or Cr. The coating agent of the insulating coating may also contain other components, such as antioxidants, surfactants, lubricants, antifoaming agents, oxidation inhibitors, and similar substances added to enhance the properties and uniformity of the insulating coating. It may also contain a known color pigment, an extender pigment, or a functional pigment. These components may be present as long as the performance of the insulating coating is not diminished, and specifically, not exceeding 5% by mass of the solid content after baking. The insulating coating can be formed using various methods, such as roller coating, flow coating, knife coating, spraying, etc. The coating weight of the coating agent to be applied is determined by ensuring sufficient insulation properties and adequate nitriding suppression. Specifically, the insulating coating is applied so that the coating weight after baking is preferably not less than 0.1 g / m², and more preferably not less than 0.2 g / m² per side.Furthermore, with the increase in coating weight, the costs of the coating material increase and the lamination factor, when formed on an iron core, decreases, and consequently, the upper limit of the coating weight on a lateral surface is preferably 10 g / m2, more preferably no more than 5 g / m2, more preferably no more than 2 g / m2. The baking method after applying the coating agent is not particularly limited, and any commonly used baking method such as hot air, infrared heating, or induction heating can be used. Furthermore, the baking temperature only needs to be within a commonly used range, for example, Rcconn / zznz / E / YiAi is preferably such that the highest temperature reached by the steel sheet is from 80 to 350°C. Furthermore, the heating time from the start to the end of heating is preferably in the range of 0.1 to 60 seconds, more preferably from 1 to 30 seconds. In the invention, the most important aspect is forming the coating layer (nitriding suppressor layer) on the surface of the steel sheet after finishing annealing. The method of forming the coating layer differs between two methods: the first, in which the nitriding suppression capability is imparted to the insulating coating formed on the surface of the iron matrix of the steel sheet; and the second, in which the intermediate layer with the nitriding suppression capability is formed between the surface of the iron matrix of the steel sheet and the insulating coating. A detailed explanation will follow. First Modality The first embodiment of the present invention consists of using an insulating coating formed on the iron matrix surface of a steel sheet after finishing annealing as a coating layer that has nitriding suppression capabilities, and is characterized by containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and B1 in the insulating coating to impart the nitriding suppression capability. By containing these elements in the insulating coating, the density and adhesiveness of the insulating coating are improved to impart the nitriding suppression effect to the insulating coating. The method for incorporating at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and B1 into the insulating coating is not particularly restricted and may employ a method of dissolving or dispersing the element as an inorganic compound in a coating agent. Elements that are soluble in the coating agent are dissolved, while those that are difficult to dissolve are mixed and dispersed. The inorganic compound may be of any form, including oxide, carbide, hydroxide, carbonate, chromate, and phosphate. The composition of these elements is preferably at least 0.001% by elemental ratio in the coating after baking. However, excessive addition can impair the coating's corrosion resistance and adhesion, so the upper limit is preferably around 10% by mass. Second Modality The second embodiment of the present invention consists of forming an insulating coating on the surface of the steel sheet after finishing annealing and an intermediate layer having a nitriding suppression capacity between the insulating coating and the surface of the iron matrix Rcconn / zznz / E / YiAi of the steel sheet, and is characterized by containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and B1 in the intermediate layer. By containing these elements in the intermediate layer, not only can a nitriding suppression effect be provided to the intermediate layer, but an insulating and antioxidant effect can also be expected. In addition, the total thickness of the intermediate layer and the insulating coating can be made thinner than the thickness of the insulating coating of the first modality, thus improving the rolling factor (core magnetic flux density). It is necessary to reinforce the bond within the insulating coating itself to achieve better scratch resistance during core production. The bond tends to weaken as the insulating coating contains a greater number of elements. However, in the second method, since the insulating coating does not need nitriding suppression capabilities, the number of elements it contains can be minimized, thus maintaining a strong bond and resulting in excellent scratch resistance. The method for forming the intermediate layer, which includes at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and Bi, is not particularly restricted. For example, a method could be used whereby a treatment solution containing the elements is applied to the surface of the steel sheet by immersion or spraying, or by roller coating or similar means, and then dried. The conditions for forming the intermediate layer (temperature and time) are not limited; however, considering productivity, it is preferable to select a method that can be processed within 10 seconds to 10 minutes at room temperature. Other methods that may be used include plating or dry processing using CVD or PVD. Furthermore, the intermediate layer formed may consist of two or more layers. The following will explain an engine core and an engine core production procedure. The core of a motor typically consists of a rotor core, which must have high strength, and a stator core, which must have low iron loss and high magnetic flux density. Generally, the rotor core is formed by stamping a steel sheet with an insulating coating applied after final annealing into a core shape, and then rolled into a fixed core for the motor. The stator core, on the other hand, is formed from a steel sheet with an insulating coating applied after final annealing. This core is then stamped, rolled, fixed, and subsequently undergoes stress-relief annealing to improve its magnetic properties. Stress-relief annealing is preferably performed at a temperature of 800 to 950°C for 0.5 to 3 hours in an inert gas atmosphere such as argon gas, nitrous oxide, or similar gases. When the stress-relief annealing temperature is below 800°C or the annealing time is less than 0.5 hours, the following procedure should be followed: For stress-relief annealing, the effect on crystal grain growth from stress-relief annealing is too small to achieve a sufficient improvement in iron loss, potentially causing the iron loss after stress-relief annealing to not meet the reference iron loss value defined by the formula described above (2). On the other hand, when the stress-relief annealing temperature exceeds 950°C or the annealing time exceeds 3 hours, it becomes difficult to ensure insulation between the rolled steel sheets. The most preferable condition for stress-relief annealing is 800 to 875°C for 1 to 2 hours. Since the steel sheet subjected to stress-relief annealing contains a suitable amount of Zn added to the steel raw material and has a coating layer capable of suppressing nitriding on the surface, the concentration of N present as AlN (N as AlN) in the surface layer to 1 / 20 of the sheet thickness after stress-relief annealing can be reduced to no more than 100 ppm by mass (no more than 0.0100% by mass). As a result, the steel sheet of the present invention can suppress the increase in iron loss caused by precipitated AlN in the 1 / 20-thick layer of the sheet and thus meet the reference iron loss value defined by the following formula (2) after stress-relief annealing: W10 / 800 = 15 + 80xt ...(2). Example 1 The plates, which have various component compositions shown in Table 1 and the remainder being Fe impurities and unavoidable, are heated to a temperature of 1120°C for 30 minutes, hot rolled to form each of them a hot rolled sheet with a sheet thickness of 2.0 mm, subjected to hot strip annealing at 930°C for 30 seconds, pickled to descale and cold rolled to form a cold rolled sheet with the final sheet thickness shown in Table 2.The cold-rolled sheet is then subjected to a finish annealing at 820°C for 10 seconds under an atmosphere of H2:N2 = 20:80 in % by volume ratio, coated with an insulating coating agent prepared by combining components A to G indicated in Table 3 in the configurations indicated in Table 2 on both sides of the steel sheet by means of a roller coater so that the weight of the coating on one side has the value indicated in Table 2, and baked in a hot air drying oven under the conditions indicated in Table 2 to produce a product sheet. Test samples with a length of 280 mm and a width of 30 mm are taken from the rolling direction (L direction) and from the direction perpendicular to the rolling direction (C direction) of the product sheet thus obtained coated with the insulating coating, and each of them is subjected to stress-relief annealing under the conditions indicated in Table 2 in a Rcconn / zznz / E / YiAi N2 atmosphere = 100% by volume under the conditions indicated in Table 2 to measure the W10 / 800 iron loss by means of the Epstein test. In addition, the steel sheet after stress relief annealing is subjected to an electrolytic extraction method to analyze the concentration of N present as AlN (N as AlN) in the 1 / 20 thickness layer of the sheet. Two test samples, 100 mm wide and 200 mm long, are taken from the lamination direction (L direction) of the product sheet coated with the insulating coating, with the length direction being measured under each condition. The two test samples are stacked on top of each other, slid at a relative speed of 2 cm / s for 10 seconds while a pressure of 1 kg / cm² is applied, and visually inspected for the presence or absence of scratching on the surface. Scratch resistance is then evaluated according to the assessment criteria below. Scratch Resistance Evaluation Criteria ©: Almost no scratching observed (acceptable) or: Some scratching observed (acceptable) x; Clear scratching observed (rejected). Additionally, two sample pieces, 100 mm wide and 200 mm long, are taken in the rolling direction (L direction) from the product sheet coated with the insulating coating as the length direction for each condition. A cellophane adhesive tape is applied to the surface to be tested, and the steel sheet is subjected to a 180° bend using a 5 mm diameter round bar with the surface to be tested as the compression side. The cellophane adhesive tape is then removed, and the peeled coating surface is measured to evaluate the coating's adhesiveness according to the following criteria. Coating adhesion evaluation criteria ©: Peeled area of ​​coating < 5% (acceptable) or: 5% < peeled area of ​​coating < 10% (acceptable) x; Peeled area of ​​coating > 10% (rejected) Rccann / zznz / E / YiAi Table 1 Comments Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Comparative steel | too δ Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | O i á O o δ Comparative steel | Inventive steel | Inventive steel | Comparative steel | Inventive steel | Inventive steel | Comparative steel | Inventive steel | Inventive steel | Inventive steel | Composition of components (°o mass) | Mo, WI 1 1 1 1 1 1 [ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Cu, Ni, Cr, Co I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Ca, Mg, REM I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 p 1 1 1 1 1 1 1 0.05 | a ω 0.03 0.03 0.03 | 0.03 0.03 Ϊ0Ό 0.03 | 1 1 1 1 1 1 3 0.04 | 0.03 £0'0 1 1 0.03 0.03 | S 0.03 0.03 £0'0 1 z 0.0022 0.0022 0.0022 0.0022 0.0022 0.0022 0.0022 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0019 OcOOO 0.0022 0.0022 0.0027 0.0027 0.0022 0.0024 0.0024 0.0022 0.0021 0.0021 0.0021 o 0.0024 0.0024 0.0024 | 0.0024 0.0024 0.0024 0.0024 | 0.0025 0.0025 0.0025 0.0025 0.0025 0.0021 1 ΙΤΟΟΟ 0.0024 0.0024 61000 6100'0 0.0024 0.0028 | 0.0028 0.0024 0.0027 0.0027 0.0027 Nb 6000° 6000'0 | 6000° 6000° 0.0009 6000° 0.0009 | P00° 0.0011 P00° | P00° P00° P00° 0.0012 0.0012 6000° 6000° 0.0012 0.0012 6000° 0.0013 | 0.0013 0.0009 t-IOO'O 0.0014 0.0009 | H I100Ο 1100'0 0.0011 0.0011 P00Ο II00Ο P00Ο 0.0013 0.0013 0.0013 0.0013 0.0013 0.0008 8000'0 0.0011 II00Ο t-IOO'O 0.0014 II00Ο I100Ο I100Ο 0.0011 9100'0 9100'0 0.0012 0.0021 0.0021 0.0021 | 0.0021 0.0021 0.0058 0.0003 0.0029 0.0007 0.0043 0.0029 0.0029 0.0029 0.0024 0.0024 0.0021 0.0021 0.0026 0.0027 0.0021 0.0032 | 0.0032 0.0021 0.0024 0.0024 0.0021 | 7? Os as as as as as Os Ó ρ pppppr 1 CO OS ci 2 2 Os pp OS OS o OS <Λ 8100Ο 8Ι00Ο 1 SI000 SIOO'O 8100Ο 8100'0 0.001S 1 0.0019 0.0019 6100Ο | 6Ι00Ο 0.0019 6100Ο 0.0024 0.0024 0.0018 8100Ο 0.0015 0.0015 8100 0 0.0026 | 0.0026 81000 61000 0.0019 0.0015 | CU 0.01 0.01 0-01 gg 0.01 g Ι0Ό s 0.01 10Ό 0.01 0.01 10'0 o Ι0Ό p 10'0 Ι0Ό o1 o1 0.01 0-01 0-010 0-1 M oo-01 Ι / Ί '<1 <Λ> '<1 WITH CO r-í or 2 ooooori with ripc·*; p in pc**¡ pr**¡ p cr¡ p ci pc<¡ co CO Ci CO in CO f*-¡ CO r <i p 0ί>r¡ 1 r< o -rpc <i -r cr¡ o-i c<>o 0.0025 0.0025 0.0025 | 0.0025 0.0025 0.0025 0.0025 | 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.002S 0.0028 0.0025 0.0025 6100'0 0.0019 0.0025 0.0021 | 0.0021 0.0025 0.0024 0.0024 1 8100'0 Steel T amine Ns r-1 T ' / Ί Ό r-· OO Os o ri 22 2 Yi Ό r-- CO Os <1 Cl r| c**ir 1 T rl ca Ό ri Rcconn / zznz / E / YiAi Table 1-2 ​Comparative Steel Comments | Comparative Steel | I Comparative Steel 1 Comparative Steel | I Comparative Steel 1 Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | I Inventive Steel 1 Inventive Steel | I Inventive Steel 1 Inventive Steel | Inventive Steel 1 Inventive Steel | Inventive Steel | Inventive Steel | I Composition of components (% by mass) I or I l 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 l 1 1 1 1 Cu, Ni, Cr, Co I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Cu: 0.05 | | ro :na Cu: 0.5 | 1 6 0 :n3| Ca, Mg, REM I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Ca: 0.0032 | 5200 0 REM: 0.0065 | Ca: 0.0021, Ms: 0.0032 Ca: 0.0015, REM: 0.0025 |Ma :0.0015, REM: 0.0035 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 or Ti 0.015 | 1 1 1 1 1 1 1 1 1 1 c ίΛ 0.03 o 1 0.03 0.03 0.03 0.03 s 2 0.03 s 0.03 p Ξ g 0.015 1 1 1 1 1 1 s 0.03 s 0.03 7. 0.0022 0.0022 I 0.0022 I 0.0022 0.0065 0.0022 0.0022 0.0022 0.0023 0.0023 0.0023 0.0031 0.0022 0.0022 0.0022 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 I 0.0022 0.0022 0.0022 0.0022 O 0.0024 0.0024 I 0.0024 1 0.0064 0.0024 0.0023 0.0023 0.0023 0.0021 0.0021 0.0021 0.0032 0.0024 0.0024 0.0024 0.0025 0.0025 0.0025 0.0025 0.0025 0.0025 I 0.0023 0.0023 0.0023 0.0023 Nb | 6000'0 | 6000 0 I 0.0038 I | 60000 | 6000'0 | 0.0013 | 0.0013 | 0.0013 0.0012 | 0.0012 | 0.0012 | 0.0013 | | 6000 0 0.0009 | | 60000 | 11000 11000 | 11000 0.0011 0.0011 | 1100'0 0.0013 | 0.0013 | 0.0013 | 0.0013 | H 1100'0 0.0041 11 ioo'o | 0.0011 0.0011 0.0012 | 0.0012 8100'0 0.0018 0.0018 0.0013 11000 0.0011 11000 0.0013 0.0013 0.0013 0.0013 0.0013 0.00131 0.0012 0.0012 0.0012 0.0012 a N 0.0021 0.0021 I 0.0021 I 0.0021 0.0021 0.0024 0.0024 0.0024 0.0019 61000 61000 0.0021 0.0021 0.0021 0.0021 0.0029 0.0029 0.0029 0.0029 0.0029 0.0029 I 0.0024 0.0024 0.0024 0.0024 σχ σχ ox σχ Ó O Ó 00 σχ σχ o Ó Ó 0.6 0.6 OOOO 00 0.0059 | 0.001 s 0.001 s I 1 8100 0 0.001 s 0.0023 | 0.0023 | 0.0023 0.0026 | 0.0026 | 0.0026 | 0.0021 | 1 81000 0.0018 1 1 8100 0 | 6100 0 6100Ό 1 61000 61000 61000 | 6100 0 0.0023 | 0.0023 | 0.0023 | 0.0023 | 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Ó 0.01 Ó 0-01 0-01 0-01 roo 0.01 0.01 0-01 0-01 0-01 O 0.01 o-o 0-0 0.4 oo Ti 5 Ti 0.9 σχ ó σχ with OO K0 Ti O Ti 5 Ti Ti o Ti o Ti o 'PO 'P -i -r 'T. 'T xo CO with CO with CO CO -r -r -r -ro 0.0025 | 0.0025 | I 0.0025 I 0.0025 | 0.0025 0.0021 | 0.0021 | 0.0021 0.0026 | 0.0026 | 0.0026 | 0.0025 | 0.0025 | 0.0025 | 0.0025 | 0.0021 | | 12000 0.0021 | 0.0021 0.0021 0.0021 I 0.0021 | 0.0021 | 0.0021 | 0.0021 | Steel sheet Ns C<0 f1 σχ rl O £ ri £ 3 Steel- CO σχ O ri 3 4 Turquoise. Rcconn / zznz / E / YiAi Table 1-3 Comments Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Composition of components (° or in mass) | Mo, WI 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 or Mo: 0.05 SV: 0.0025 SV: 0.06 Mo: 0.0025, SV: 0.0025 Mo: 0.0025 Mo: 0.0025 Cu, Ni, Cr, Co O Ti U Os or U Ni: 0.05 ΓΟΐί or Z Ni: 0.9 Co: 0.05 Co:0.1 1 C0:OD| Os or O Cu: 0.3, Ni: 0.3 Cr: 0.3, Co: 0.3 Ni: 0.3, Co: 0.3 Cu: 0.3, Co: 0.3 1 1 1 1 1 1 1 Ca, Mg, REM I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 tCOO O :e3 KOO'O^OI 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 CO) 0.04 0.04 too o § ooo 0.03 0.03 0-03 § t-0'0 0.04 § ooo 0.03 § 0.03 § 1 Z 6100'0 6Ι00Ό 61000 6Ι00Ό 0.0023 0.0023 0.0023 0.0023 0.0021 0.0021 0.0021 0.0021 0.0020 0.0020 0.0020 0.0020 0.0022 0.0022 0.0022 0.0022 0.0022 r | O 0.0022 o 0.0021 1Γ00I 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.0027 ¿'OO'O ¿'OO'O ¿200'0 0.0021 0.0021 0.0021 0.0021 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 Nb 0.0012 0.0012 0.0012 0.0012 0.0012 0.0012 0.0012 0.0012 0.0014 0.0014 0.0014 0.0014 0.0012 0.0012 0.0012 0.0012 6000'0 6000'0 6000'0 6000'0 6000'0 6000'0 6000'0 £8000'0 SOOO'O 8000'0 8000'0 0.0018 8100'0 81000 8100'0 91000 9100'0 9100'0 9100'0 0.0008 8000'0 8000'0 8000'0 0.0011 0.0011 0.0011 0.0011 0.0011 0.0011 0.0011 Zn 0.0024 0.0024 0.0024 0.0024 0.0019 6100Ό 0.0019 0.0019 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0021 0.0021 0.0021 0.0021 0.0021 1200'0 0.0021 3 f 1 Cl C| rj TT 0.9 Cb Cb os cq CO CO O Os 0.9 Os Os Os 0.9 üO 0.0024 0.0024 0.0024 0.0024 0.0026 0.0026 0.0026 0.0026 6100Ό 6100'0 6100'0 61000 0.0024 0.0024 0.0024 0.0024 8100'0 8100'0 8100'0 81000 1 8100'0 81000 8100'0 cu 0.01 0.01 0-01 ooo O o 0.01 o-oi 0-01 0.01 oo o-oi o O o 0.01 o 0.01 § 0.01 Mn co co CO CO Cb Cb Cb Cb r-| rir 1 r | 00 CO CO GO 2 o 0.4 oo 0.4 0.4 J5 CJ T -r -r TT -r -r -r rq pppp PO 0.0028 0.0028 0.0028 0.0028 0.0026 0.0026 0.0026 0.0026 0.0024 0.0024 0.0024 0.0024 0.0028 oo y 0.0028 0.0028 0.0025 0.0025 0.0025 0.0025 0.0025 0.0025 0.0025 Lámina de acero Xs ri $ Ti jo Ti TTS 5 y S 3 3 5 Cb 1? r-~ ri r-> £. Rcconn / zznz / E / YiAi Table 2-1 Inventive Example | I Inventive Example 1 Inventive Example | Inventive Example | Inventive Example 1 I Comparative Example 1 Comparative Example | Inventive Example 1 Inventive Example I Inventive Example | Inventive Example | I Comparative Example 1 Inventive Example I Inventive Example 1 Inventive Example | Comparative Example | I Comparative Example 1 I Inventive Example 1 Inventive Example I Comparative Example 1 Inventive Example | Inventive Example | I Comparative Example 1 I Inventive Example 1 Inventive Example I Inventive Example | Comment! steel amine Coating adhesiveness evaluation ooo 0 o 0 ooo 0 o 0 ooo 0 oo 0 oo 0 0 o nj ip C •O °1 je et: í r / i O ώ w efe 1; scratch resistance ooooooooooooooo • oo 1 oo 1 ooo Iron loss I? co r| or | 0'tt r- i Os ri r- | 33.8 40.1 os 30.4 30.2 os r| 39.8 co r· 1 Os -r • rj os r-1 • co CO Os ios?; (Wkgi Iron loss ref. value 15+8O*tp 1 0 sf 39.0 31.0 0c 1 oy? | 35.0 1 os-f TÍ Osf 31.0 1 35.0 I 35.0 1 9^ 0 <f O T¡ TÍ 39.0 31.0 • 1 os-í TÍ 36.6 £ a) en „ 8 Ό <Li I 0.0042 I o e o (% en mas una capa 120 de es¡ de lámu después« recocido alivio d tensiói 0.003: o 0.0033 O 0.0031 0.0141 0.002: 0.003S 0.0031 0.002: 0.003$ 0.0041 0.004$ 0.004: 0.006: 0.006: 0.003$ 0.003S 0.003$ 0.004: 0.002$ iones de 1 ido de alivio de tensión Tiempo (hr) --1 —1 -- --1 1-1 --1 —· -- - r i —· --1 —· --1 — Condici recocí Temp. CO co Ti ώ co co co co Ti f 1 CO e i co Ti ri CO •Ί CO s s co Ti r i co ΓΊ co s Os 8 Os rj CO r-4 co co ώ r 1 CO υ o Temp.c homeac (:C) rq O + 4 o rq n r4 + 4 Γ4 + 4 <"4 <"4 ^4 o -4 N • >-4 + 4 <-4 rd C4 ?4 + 4 Baking time (s) ΓΊ rj ΓΊ Γ4 ΓΓΊΊ r ΓΊ r) ΓΊ ΓΊ ΓΊ ΓΊ ΓΊ ri ri ( ΓΊ ΓΊ ΓΊ Insulating coating Weight of the slow coating (gm:) >ri Ti τ· Ti Ti Ti Ti Ti Ti Ti Tien Ti Ti Ti Ti of Ti Ti) Concentration of Ti Do2 Concentration 2 2 2 2 2 • 2 2 Other O 2 2 2 2 2 • 2 2 2 Other OOOOO oa Uh • • OO o OOOW ooooooooooo • Q 1 1 • • • iou • • • • • - 5 ooooooo Thickness ¿nal of the sheet t (mm) r ί ri Ó 0.30 | 1 gold Ti r 1 Π 1 0.20 | FH Ó FH 1-1 r 1 r ¡ r ΐ 1 ofo 0.20 | r ί f í rj Steel sheet Xa r| -t Ti Ό r- CO Os 2 r4 2 2 2 ·"· co Os Γ4 rl Γ4 r^j Γ4 O Γ4 1” The rc OJ — Λ 1) rc K rc 1» rc or rc o (U tu c (U Rccann / zznz / E / YiAi Table 2-2 ​Comments Comparative Example | Comparative Example | Comparative Example | I Comparative Example 1 I Comparative Example 1 Inventive Example 1 pi á 0 iw Inventive Example 1 Inventive Example 1 Inventive Example | Inventive Example 1 Inventive Example | Inventive Example | Inventive Example | I Inventive Example 1 Inventive Example I Inventive Example 1 Inventive Example | Inventive Example 1 Inventive Example I Inventive Example | Inventive Example | Inventive Example | Inventive Example II Inventive Example 1 Inventive Example I Steel Sheet Properties Evaluation of Coating Adhesiveness ooooooooooooooooooooo oooo Evaluation of Scratch Resistance ooooooooooooooooooooo oooo Iron Loss w105M (Wke) Actual Value 'Cl 3 3 Os 1 44.6 I CN eq cq 1 32.0 I r 1 Os r| r 1 oq co c-.| oo rrq Os r-' rq Os rq rq r 1 rq rq rl CNC 1 Os 24.8 1 24.8 I CN Iron loss rei value 15+80*1 35.0 35.0 35.0 1 35.0 I 1 35.0 I 1 31.0 I 35.0 1 39.0 I rq 31.0 35.0 35.0 35.0 1 35.0 I 35.0 1 35.0 I 35.0 1 35.0 I one layer of 1 20 sheet thickness after strain relief annealing 0 0045 0.0041 0.0043 | | Ι800Ό | I 0.0051 I 0.0053 0.0059 I 0.0054 0.0051 0.0053 0.0052 ΙΪ00Ό I 0.0032 I 0.0032 I 0.0024 I 0.00020 I4 0.0024 0.0051 0.0051 I 0.0051 I 0.0051 Stress relief annealing conditions Time (hr) ·- --1 .-1 5 rq --1 .-1 —· Temp. CO 8 co 8 co 8 00 I 8 00 2 oo oo oo 8 CN 00 CN 00 CN OO CN OO CN CO sss Insulating coating Temp. of baked goods 00 CN CN gold) cN o cn dry goods ^1 N good good old days old £q CN good old Baking time(s) γί O r | θ ri Cl Cl ri ri Weight of coating (g m2) ooo O 'Ci o ir.oooo O ifi O Ó ooooooooo Concentration of solids content (°oen mass) ooo OOO 2 2 2 2 2 2 2 OOO 2 2 2 2 oo 2 2 OI Other I ooo OOOOO Organic 1 oOo O oooo O oooo • • oO 1 Q • • o • • □Q oooo 0 o O ooooo • • ooooooooo Final sheet thickness t (mm) C 1 Cl r) riri I 0.20 I Γ j 0.30 I0 •Ζ. in C 1 recurrence 1 rq C 1 0.20 | | 02Ό I 0.20 I 0.20 | Steel sheet Xs this OO this Os this 3 C*-! rq cn Cn r Rcconn / zznz / E / YiAi Table 2-3 ​Comments Inventive Example | Inventive Example | Inventive Example | I Inventive Example 1 I Inventive Example 1 I Inventive Example 1 I Inventive Example 1 Inventive Example | I Inventive Example 1 I Inventive Example II Inventive Example 1 I Inventive Example 1 I Inventive Example 1 Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example 1 Inventive Example | Inventive Example | I Inventive Example 1 I Inventive Example 1 Inventive Example | Props. of the steel sheet Evaluation of the adhesiveness of the coating ooo 0 o 0 o 0 ooooo OOOOOOOOOO Evaluation of the scratch resistance ooooooooooooo 0 0 0 0 0 0 0 0 0 0 Iron loss w10S,: (Wkg) Actual value N oí n oí n Os c 1 ri Γ4 ΓΊ ΓΊ ri ΓΊ ΓΊ γί nf| N ΓΊ o. o ΓΊ ΓΊ co <> ΓΊ Os 'O ΓΊ ri T» ΓΊ ci T» r-4 ri Ti 32.0 1 31.9 I r-4 C4 Ref. of iron loss 15-SO*t 36.6 | 36.6 | 1 9-9L 1 1 1 ost 1 1 Off 1 1 ost 1 Ti 1 ost 1 1 oTt Ti Ti 1 1 0·^ 1 0·^ 1 0·^ 39.0 | 39.0 I 39.0 | 1 1 0'6í 1 1 39.0 I 39.0 | N as A1N (° or en masa) in a capa de 1 20 de lamina thicknesses after the removal of voltage supply | 0.0049 | 0.0049 | 0.0049 I 0.0049 1 1 0.0053 I 0.0053 1 0.0053 0.0053 0.0039 0.0039 0.0039 I 0.0039 I 0.0045 | 0.0045 | 0.0045 | 0.0045 | 0.0032 0.0032 | 0.0032 0.0032 0.0032 0.0032 | 0.0032 Condiciones de recocido de alivio de tensión Tiempo (hr) -1 -1 - -1 -1 -1 —' - —· -1 -1 -1 -1 -1 - 1 Temp. eo ri co ri co rJ OO rJ OO co ώ ώ ώ ώ o co ώ co r| CO Γ Ί CO ri CO ri CO & ώ ώ 00 ώ Recubrimiento aislante Temp.of baked goods ΓΊ Baking time (s) θ θ θ θ θ θ F; R θ Γ4 θ rj rj Γ4 Γ4 Weight of the recubnment (gm;) Ti Ti Ti t Tit Weight Τι Solids Content Concentration (% by mass) ^-1 O i O 2 2 Other | 0 • Earring Ο OOO - • • w OOOOOOOOO 0 O 0 0 0 o 0 OOO Inorganic Q • • • • • • CQ oooo • - • • • ooo 1 0.27 rq ¿4 Γ4 ¿4 ¿4 <ί ΓΊ r-4 / 4 Γ4 / 4 ¿4 1 0.30 0.30 0.30 1 0.30 0 0-3 r-4 · / ·» Ti t Tl Ti Ό Ti Ti OO ΤΊ Os ΤΊ S 5 3 3 3 OO 5 CO 0 δ 0 r-· r-- ΓΊ -1-. Table 3 Product Name Monomagnesium Phosphate manufactured by Taihei Chemical Industrial Co., Ltd. A-2550 manufactured by Nissan Chemical Corporation T0058 manufactured by Tokyo Chemical Industry Co., Ltd.: ST-C (silica sol) manufactured by Nissan Chemical Corporation = 1:15 (mixture) 1980352 manufactured by Fujifilm Wako Pure Chemical Corporation: STC (silica sol) manufactured by Nissan Chemical Corporation = 1:30 (mixture) EFD-5S60 manufactured by DIC Corporation R-966 manufactured by Kusumoto Chemicals Ltd. SURFYNOL400 manufactured by Nissin Chemical Industry Ltd. Classification Inorganic material containing P Inorganic material containing Sb Inorganic material containing Sn Inorganic material containing Se Organic resin Organic resin Other component Name Monomagnesium Phosphate: Mg1H1PO2 Antimony Pentoxide Sol: Sb2O; Tetrabutyltin: (CrHsLSn Selenium dioxide powder: SeO; Aqueous acrylic resin Aqueous polyether resin Surface active agent No. < PQ u Q w 0 Rcconn / zznz / E / YiAi The results are also shown in Table 2. The result shows that the steel sheets produced under conditions adapted to the present invention all have excellent iron loss, scratch resistance and coating adhesion properties. Example 2 The plates, which have various component compositions shown in Table 4 and the remainder being unavoidable Fe impurities, are heated to a temperature of 1120°C for 30 minutes, hot rolled to form each of them a hot rolled sheet with a sheet thickness of 2.0 mm, subjected to hot strip annealing at 930°C for 30 seconds, pickled to descale, and cold rolled to form a cold rolled sheet with the final sheet thickness shown in Table 5. The cold rolled sheet is then subjected to finish annealing at 820°C for 10 seconds under an atmosphere of H2:N2 = 20:80 in % by volume ratio, coated with a treatment agent A or B shown in Table 6, and dried to form an intermediate layer having a coating thickness of 5 to 100 nm after drying.A coating agent for the insulating coating prepared by combining components C to G shown in Table 6 in the configurations shown in Table 5 is applied to both sides of the steel sheet by means of a roller coater so that the coating weight on one side has the value shown in Table 5, and is baked in a hot air drying oven under the conditions shown in Table 5 to produce a product sheet. Test samples, 280 mm long and 30 mm wide, are taken from the rolling direction (L direction) and the direction perpendicular to the rolling direction (C direction) of the resulting product sheet, which has the intermediate layer and insulating coating. These samples are then subjected to stress-relief annealing under the conditions shown in Table 5 in a 100% vol. N₂ atmosphere to measure the W10 / 800 iron loss using the Epstein test. In addition, the steel sheet after stress-relief annealing is subjected to an electrolytic extraction method to analyze the concentration of N₂ present as Al₂ (N₂ as Al₂) in the 1 / 20-thick layer of the sheet. Two test sample pieces with a width of 100 mm and a length of 200 mm are taken in the lamination direction (L direction) of the product sheet having the intermediate layer and the insulating coating as the length direction in each condition, as in Example 1. The two test samples are stacked on top of each other, slid at a relative speed of 2 cm / s for 10 seconds while a pressure of 1 kg / cm2 is applied and visually observed to determine the presence or absence of scratching on the surface of the test samples, from which the scratch resistance is evaluated according to the evaluation criteria below. Scratch resistance evaluation criteria ©: Almost no scratching is observed (acceptable) or: Some scratching is observed (acceptable) Rcconn / zznz / E / YiAi χ: A clear (rejected) scratch pattern is observed In addition, two sample pieces, 100 mm wide and 200 mm long, are taken along the rolling direction (L direction) of the product sheet coated with the insulating coating under each condition. A cellophane adhesive tape is applied to the surface to be tested, and the steel sheet is subjected to a 180° bend using a 5 mm diameter round bar, with the surface to be tested as the compression side. The cellophane adhesive tape is then removed, and the peeled coating surface area is measured to evaluate the coating's adhesiveness according to the following criteria. Coating adhesion evaluation criteria ©: Peeled area of ​​coating < 5% (acceptable) or: 5% < peeled area of ​​coating < 10% (acceptable) χ: Peeled area of ​​coating > 10% (rejected) Rcconn / zznz / E / YiAi Table 4-1 IL O iao (J Inventive steel | Inventive steel | Inventive steel | Inventive steel | | OAHEIEdnioD ojaoy Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel | Inventive steel 1 Comparative steel | | oAHEJEdmoa oraov Inventive steel | Inventive steel | Comparative steel | Inventive steel | Inventive steel | Comparative steel | Inventive steel 1 Inventive steel | Inventive steel | Composition of components (° or by mass) | Mo, WI 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Cu, Ni, Cr. Co I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Ca, Mg, REM I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 (Λ I 1 1 1 1 1 1 1 1 1 1 1 1 o 1 1 1 1 1 1 1 0-05 al / ) 0.03 | 0.03 0.03 £0'0 δ 1 1 1 1 0.04 | 3 1 1 1 1 1 0.03 δ 90 0 δ 0.03 1 % 0.0022 0.0022 0.0022 0.0022 0.0022 0.0024 0.0024 0.0024 0.0024 0.0019 0.0020 0.0028 0.0021 0.0027 0.0027 0.0028 0.0024 0.0024 0.0024 0.0021 0.0021 0.0021 or 0.0024 0.0024 0.0024 0.0024 0.0024 0.0025 0.0025 0.0025 0.0025 0.0021 0.0021 0.0021 0.0021 0.0019 0.0019 C 1 o 0.0028 0.0028 0.0028 0.0027 0.0027 0.0027 Nb 6000'0 6000'0 60000 60000 60000 0.0011 0.0011 0.0011 1100'0 0.0012 0.0012 0.0011 0.0011 0.0012 0.0012 0.0011 0.0013 0.0013 0.0013 0.0014 0.0014 60000 P 0.0011 0.0011 II0000 0.0011 1100'0 0.0013 0.0013 0.0013 0.0013 S000 0 SOOO'O 0.0008 SOOO'O 0.0014 0.0014 SOOO'O 0.0011 0.0011 0.0011 91000 9100'0 0.0012 tN 0.0021 0.0021 0.0021 0.0021 0.0003 0.0029 0.0029 0.0029 0.0029 0.0024 0.0024 0.0021 0.0015 0.0026 0.0027 0.0038 0.0032 0.0032 0.0025 0.0024 0.0024 0.0021 O\ O, Oh O; <2 ri CO Ti Ti Ti Ti Oh Oh Oh C- Oh < / ) 0.001S SI000 SIOO'O SIOO’O SIOO'O 61000 0.0019 61000 61000 0.0024 0.0024 I 0.0024 0.0024 I <100'0 <100'0 0.0024 0.0026 0.0026 0.0026 I 6100 0 6100Ό 0.0015 Oh 0.01 10'0 0 01 ó 0.01 0.01 0-01 0.01 0.01 ooi 0-01 O O 0-01 001 o 001 o.oi r\ 0-01 0.01 0.01 Mn t'0 t'0 f'O t-'O t-'O Ti Ti Ti Ti OO CO ó Ti Ti ei Γ0 O O Cj co Cl <75 e Ti τ «¡ OO OO CO OO Ti c-| r-1 £ C I Ti r l -r r 1 -r Ti Ti O 0.0025 0.0025 0.0025 0.0025 0.0025 0.0021 0.0021 0.0021 0.0021 0.0028 0.0028 0.0029 0.0025 6100'0 0.0019 0.0022 0.0021 40.0021 40.00021 SIOO'O Steel sheet ΤΊ or CO σι ori δ 1 Ό CO Os c-| C 1. Rcconn / zznz / E / YiAi Table 4-2 Commentaries | | oATiEieduioa ojaay Comparative Maple | Comparative Maple 1 Comparative Maple | Comparative Maple | Inventive Maple | Inventive Maple | Inventive Maple | Inventive Maple | Inventive Maple | I Inventive Maple 1 Inventive Maple | Inventive Maple | Inventive Maple 1 Inventive Maple | Inventive Maple | Inventive Maple | Inventive Maple | Inventive Maple | Inventive Maple | Inventive Maple | Inventive Maple | Composition of components (° or in mass) | Mo, \V 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Cu, Nl Cr, Co 1 1 1 1 1 1 ll 1 1 1 1 1 1 1 1 ll Cu: 0.05 Cu: 0.1 u Cu: 0.9 Ca Mg, REM 1 1 1 1 1 1 1 1 1 1 1 1 Ca: 0.0032 Mg: 0.0023 REM: 0.0065 Ca: 0.0021, Mg: 0.0032 Ca: 0.0015, REM: 0.0025 Mg: 0.0015, REM: 0.0035 1 1 1 1 ω 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 cgggpoopo 2 PPP 1 1 1 1 1 1 P goi Z 0.0026 0.0026 0.0026 0.0026 0.0065 0.0022 1 or <1 or 0.0023 0.0023 0.0023 I 0.0031 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0022 0.0022 0.0022 ri or O 0.0029 0.0029 0.0029 0.0064 0.0021 0.0023 0.0023 0.0023 0.0021 0.0021 0.0021 0.0021 2 0.0025 0.0025 2 0.0025 0.0025 0.0023 0.0023 0.0023 0.0013 0.0013 0.0038 0.0011 1100'0 0.0013 0.0013 0.0013 0.0012 0.0012 1 0.0001 0.0011 0.0011 0.0011 1100'0 1100'0 0.0013 0.0013 0.0013 0.0013 8Ι00Ό 0.0041 0.0007 0.0007 2 0.007 0.0012 8Ι00Ό 0.001 s 0.001 s I 0.0013 0.0013 0.0013 0.0013 0.0013 0.0013 0.0013 0.0012 060012 0.00012 0.00012 0.0012 0.0021 0.0021 0.0021 0.0021 0.0024 0.0024 0.0024 61000 0.0019 61000 0.0021 0.0029 0.0029 90.0029 0.00029 0.0024 0.0024 0.0024 0.0024 3 o 'Al Ti OO r*-- O -r -r -ro Ó MO o s© 1. oo r- ( / ) 0.0059 I 0.0015 0.0015 0.0015 0.0015 0.0023 0.0023 0.0026 0.0026 0.0026 I 0.0021 6Ι00Ό 6100'0 0.0019 0.0019 0.0019 6100'0 0.00023 0.0023 0.00023 0.00023 oooc> § ( o TH ooooo 1 o TH o TH o á so r! r! r! ot> T> t> Os Os oo Ti Ti t> τ· 'Γι 'Γι0021 0.0021 0.0021 0.0026 0.0026 0.0026 I 2 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 í-8 § ·- 3 r. t kJ S rt -r O Γ-- CO Oso 2 2 jo 2 CO O. orj T T. Rcconn / zznz / E / YiAi Table 4-3 Comments | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | oio Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | Inventive Steel | | oatjuoaut ojaoy Component composition (% by mass) | For, W 1 1 1 1 1 1 1 1 1 1 1 1 1 1 For:0.0025 ,ó |W:0.0025 W:0.06 € | ,p ΓΊ o ó ,Q ,q Cu, Ni Cr, Co Cr:0.05 u T) U Cb O Ni:0.05 5 Ti Z Cb 2 Co:0.05 Co:0.1 - 9'°Á Cb 6 UC**iu ί*Ί O ó, O £ 1 , Ca 1 u 1 u 3 REM | 0.04 § 0-03 o 0-03 § 0-03 o 0.04 0.04 0.04 | θ-04 ó ooo 0.03 ó 1 z 6Ι00Ό 6Ι00Ό 0.0019 6100'0 0.0023 0.0023 0.0023 0.0023 0.0021 0.0020 0.0020 I 0.0020 0.0022 0.0022 0.0022 0.0022 0.0022 | 0.0022 0.0022 o 0.0021 0.0021 0.0021 0.0021| 0.0021 0.0021 0.0021 0.0021 0.0027 0.0027 Cl § 0.0027 0.0021 0.0021 0.00211 0.0021 0.0024 0.0024 0.0024 0.0024 0.00241 0.0024 0.0024 Nb 0.0012 0.0012 0.0012 0.0012 0.0012 0.0012 0.0012 0.0012 0.0014 0.0014 0.0014 0.0014 0.0012 0.0012 0.0012 0.0012 6000'0 6000'0 6000'0 6000 0 6000'0 6000'0 6000'0 H 8000 0 8000'0 8000 0 8000'0 0.0018 81000 8100'0 81000 | 9100 0 91000 91000 91000 8000 0 0.0008 | 8000'0 8000 0 0.0011 II00Ο P00Ο 0.0011 | Π00Ό 0.0011 Π00Ό a N 0.0024 0.0024 0.0024 0.0024 6Ι00Ι 6I00Ι 6100'0 6100'0 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0024 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 0.0021 rjrjcirj -r -r -r 'T 0-9 Cb 0.9 Cb 00 oo CO co <*l Cb Cb Cb 0-9 O. 00 0.0024 0.0024 0.0024 0.0024 0.0026 0.0026 0.0026 0.0026 0.0019 0.0019 0.0019 0.0019 0.0024 0.0024 0.0024 0.0024 8100Ε 0.0018 8100'0 0.0018 0.0018 0.0018 0.0018 CL O 0.01 0.01 0.01 0.01 0.01 0.01 § 0.01 0.01 0.01 0.01 § o 0.01 0.01 Ó 0.01 oo 0.01 O 0.01 Mn co co 00 co Cb Cb Cb Cb Cl c 1 ri ΓΊ 00 OO CO co o ó OO oo ó 'cZ Γ I risk -r -T -f -r T rl ri ri rl 9'8 0.0028 0.0026 0.0026 0.0026 0.0026 0.0024 0.0024 0.0024 0.0024 0.0028 0.0028 0.0028 | 0.0028 0.0025 0.0025 0.0025 in O 0.0025 | 0.0025 0.0025 Steel sheet No O rf -r CO τ Ti r-| You t! .7. t! T You CO S 5 s 3 OR Rccann / zznz / E / YiAi Table 5-1 Comments Inventive Example | Inventive Example | I Inventive Example 1 Inventive Example | Comparative Example | Inventive Example | Inventive Example | Comparative Example | Inventive Example | Inventive Example | Inventive Example | Comparative Example | Comparative Example | Inventive Example | Inventive Example | Comparative Example | Inventive Example | Inventive Example | Inventive Example | Steel Sheet Props Coating Adhesiveness Evaluation © © © © © © © © O o OO o O o O © © © © © O Scratch Resistance Evaluation © © © © © © © © o 0 oooo 0 o © © © © © O Iron Loss WIOsH (W kg) Actual Value co r 1 $ co oi <4 o CO oj Ch OJ co Os 04 r~. 04 O 4 04 mD 04 oí CO 04 -r cd 04 cd 04 ay co Ref. value. iron loss 15+80*t 35.0 oi / 4 35.0 s O-YES 0- <f Q Q O-Sf Q OOP 30.0 O-Sf 35.0 Olf N as A1X (°« in bulk) in a 1 20 sheet thickness layer after stress relief annealing 0.0035 0.0032 0.0034 0.0037 0.0140 0.0024 0.0024 0.0039 0.0041 0.0049 0.0045 S9000 0.0064 0.0039 0.0038 0.0039 0.0045 0.0029 Stress relief annealing conditions or S Ή 2 o - - - OI - -- - - - - - d. ay £ ώ co co co co 00 co g Γ-- g co co co g Os g Ch 00 t / > co co co co Insulating coating Temp.de horneado (:C) rq ^4 04 04 04 OI 04 04 04 04 04 04 oí oí 04 04 o 04 04 04 r4 Tiempo (s) de hornead 0 ri ri ri ΓΙ OI OI O) rí eí OI OI ΓΊ OI OI O) rí OI OI rj OI ri rj Peso del recubrimi ento (gm:) 5 ó 5 5 ó Oí 5 5 5 ifi 5 5 o 5 o 5 Oí o 5 2 0 5 Concentración del contenido de sólidos (°oen masa) ooo O o OO ooo O o 2 O 2 OO 2 O 0 0 O Otros oooo • OO - 0 Orgánico u- • • • • oo 0 0 0 0 UJ oooooooooooooooo • Inorgánico Q • • - • O o 0 oooooooooo 0 oooo 0 ooo O 0 0 O Capa intermedia £0 • oooooooo • 0 oooooooo • • • oo 0 0 0 Espesor final de la lamina t (mm) o ó ó 04 0.20 04 04 04 04 04 ó 0.30 o ó 04 04 r 4 Tu mi na de acero .Ve f 4 1 / 1 O r- CO Os oo 4 fO| Ol 2 co 0 ri OI r 1 rj. *: No can produce nos. 12. 13 and 17 due to the adjustment of the plancha. No can produce no. 19 Due to the rota of the lamina in the laminado in freezing. Table 5-2 Comments Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example Inventive Example! Inventive Example! Inventive Example! Inventive Example! Inventive Example! Inventive Example! pio 9· S w' I Inventive Example] Inventive Example] Inventive Example] Inventive Example] Inventive Example] Inventive Example] Inventive Example] Inventive Example] Steel Sheet Properties Coating Adhesiveness Evaluation o O © © © ooo © ooo © © © © © oo O o Scratch Resistance Evaluation o O © © © oooaooo ¢3) <í¡> © í>) © © oooo Iron Loss Wi;sw (Wkg) Actual Value $ 3 4 40.9 44.6 r 1 c| ri C| oo ri r 1 ' / •1 c| r| rU r-| Γ1 r.| CI 01c -rr 1 -rr 1 -r 1 -r r.| Ice loss rei value 15-S0*t 35.0 35.0 35.0 35.0 35.0 30.0 OS£ 40.0 c·; 30.0 35.0 0<£ 0S£ 1 35.0 1 35.0 35.0 35.0 p 30.0 30.0 30.0 30.0 i JM t । S „ .·§ § | 0.0045 | i 0.0044 180ΟΌ 0.0051 | 0.0053 0.0059 | 0.0054 | 0.0051 | 0.0053 | 0.0052 | 0.0024 | 1 0.0024 1 0.0024 | 0.0024 | 0.0024 | 1 0.0024 I 0.0051 | 0.0051 | 0.0051 | 0.0051 | 8 -8 g -S 3 .g 3 § r | g ε 3 $ ω 3 Time (hr) TH TH tH ' / −1 c| — T— rH TH r—f Si OO S oo oo oo oo oo § oo oo f· I oo c- i oo cu oo oo CJ oo oo oo oo Insulating coating Baking temperature (Ό baked θ θ θ θ θ this θ θ Cl CU θ Cl this Cl ΓΙ θ this Weight of coating (gm;) o < / Ί Γι i^i o O o o ' / ~l r O IC| 'Γι ir. o O O <Γι o •r>oo Concentration of solids content ( i bulk) OOOO o OO ooo O 2 o OO o 2 O Others 0 • o O oo • oo O o Organic • • oooo • ooo O o o oooo • • • oo • O oooo O • Inorganic Q oooooooooooooo 1 oooooooooooooo ooooooooooo Intermediate layer CQ oooooooooooo • oooooooooooo Final sheet thickness t (mm) c ΐ c-ΐ cj CU C ί 0.20 Cj 0.30 | 0.20 CI cu cu cu cu cu<?> CJ CJ 0.20 0.20 Steel sheet 4. Rccann / zznz / E / YiAi Table 5-3 Comments Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | I Inventive Roll 1 | 0ΛΠΠ3ΛΙΙΙ ojdtuaíq Inventive Roll 1 I Inventive Roll 1 Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | Inventive Example | I Inventive Roll 1 Inventive Example | Props. of the steel sheet| Evaluation of coating adhesiveness oooo © © © © © © © © oooo © © © © © © © Evaluation of scratch resistance oooo © © © © © © © oooo © © © © © © © Iron loss Wnscc OVkg) Actual value oí ci ri ri C 4 ni oí CI G3 fl riri SO ΓΊ go ri r*- r 1 Γ*- ΓΊ fl oí ri oí CI oí CI oí ri 32.6 32.6 in Ref. value. of iron loss 15-80"t 1 0« 1 37.0 | 37.0 | rj n| rJ rj 1 o?? 1 1 o?? 1 1 1 1 1 1 37.0 | | 00t 40.0 | 40.0 | 40.0 | 1 o-ot I 40.0 1 40.0 | lo -g ! i U lililí £ θ’. 8 3 s 3 0.0049 | 0.0049 | 0.0049 | 0.0049 | 0.0054 | 0.0054 | 0.0054 | 0.0054 | I 0.0039 I 0.0039 | 0.0039 I I 0.0039 I 0.0049 | 0.0049 | 0.0049 0.0049 | 0.0032 | 0.0032 0.0032 | 0.0032 | 0.0032 | I 0.0032 1 0.0032 | Condiciones de recocido de alivio de tensión Tiem po (hr) t-H t-H T-H T-H t-H r-H T-H t-H t-H t-H t-H v-H t-H r-H T-H T-< T-H r—< t-H t-H T-4 Temp.CO • O rj GO Ti GO r} GO Ti GO s co c2 go ώ ώ η 1 GO Ti GO r-| GO r 1 OO GO ώ GO GO ώ GO GO Insulating coating | t-8 l'-sg Η Λ ni ηΊ O n 1 o <*- | n1 ηΊ O and ηΊ r-1 n 1 O <*- | o O 1 r-1 Baking time (s) do rj CJ O ΓΝ CJ FH ni ΓΊ CJ rn CJ CJ ni ΓΝ θ FH ni ΓΊ FH FH rj CJ ni Weight of the coating (gm;) Baking Time (s) 1 sfoooooooooooooooooo Other 0 Organic o OO ooooo • M ooooo O ooo O O ooo Inorganic Q oooo - • • - O oooo • ooooooooooooooo Inteimedia layer ooooooooo- CQooooooooo Final thickness of the sheet t (mm) e- ' ?co r- i e-! You You You You n 1 r 1 F-| FH 0.27 | t-1 Is U0 c1 0.30 | 0.30 0.30 | 0.30 | 0.30 | I 0.30 1 0.30 | We swim steel .Vs '4 r- oo O. Ti r-1 Ti Ti •ΓΊ T Ti oo Ti € 5 rj s© SO 3 3 8 SO. Rccann / zznz / E / YiAi Table 6 Product Name | PB-L47 manufactured by Nihon Parkerizing Co., Ltd. Sputtering Target manufactured by Advantec Co., Ltd. ST-C by Nissan Chemical Corporation. | AS-200 manufactured by Nissan Chemical Corporation EFD-5560 by DIC Corporation R-966 manufactured by Kusumoto Chemicals Ltd. | SURFYNOL400 manufactured by Nissin Chemical Industry Ltd. Classification Pretreatment agent containing P (chemical conversion treatment) Pretreatment agent containing Sn (high-frequency sputtering method) Inorganic Material Inorganic Material Organic Resin Organic Resin Other Component Name Manganese Phosphate: Ma;(POj(OH) )?(PO4):· 4H2O Metal Sn Silica Sol Alumina Sol Aqueous Acrylic Resin Aqueous Polyether Resin Surface Active Agent or < u Q w U-. O The results are also shown in Table 5. The results show that the steel sheets produced under conditions adapted to the present invention all have excellent iron loss properties. Furthermore, compared to Table 2, the scratch resistance and adhesion of the coating are further improved by providing the intermediate layer that has a nitriding-suppressing effect between the insulating coating and the iron matrix surface of the steel sheet. The invention of the present invention has an effect on increasing the strength of the insulating coating and can be applied not only to the field of non-oriented electrical steel sheets, but also to grain-oriented electrical steel sheets. ​

Claims

CLAIMS 1. A non-oriented electrical steel sheet having a component composition comprising: C: not more than 0.0050% by mass, Si: 2.8 to 6.5% by mass, Mn: 0.1 to 2.0% by mass, P: not more than 0.10% by mass, S: not more than 0.0050% by mass, Al: 0.3 to 2.0% by mass, N: not more than 0.0050% by mass, Zn: 0.0005 to 0.0050% by mass, Ti: not more than 0.0030% by mass, Nb: not more than 0.0030% by mass, O: not more than 0.0050% by mass, the remainder being Fe and unavoidable impurities, and having a coating layer containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb and B¡ on the surface of the steel sheet.

2. The non-oriented electrical steel sheet according to claim 1, wherein the non-oriented electrical steel sheet contains, in addition to the component composition described above, at least one composition group selected from the following Groups A to D: Group A: one or two selected from Sn: 0.005 to 0.20% by mass and Sb: 0.005 to 0.20% by mass; Group B: one or two or more selected from Ca, Mg and REM between 0.0005 and 0.020% by mass in total; Group C: one or two or more selected from Cu, Ni, Cr and Co in 0.01 to 1.0% by mass in total; and Group D: one or two selected from Mo: 0.001 to 0.1% by mass and W: 0.001 to 0.1% by mass.

3. The non-oriented electrical steel sheet according to claim 1 or 2, wherein the coating layer is an insulating coating formed on an iron matrix surface of the steel sheet.

4. The non-oriented electrical steel sheet according to claim 1 or 2, wherein the coating layer comprises an insulating coating formed in an upper layer on the surface of the steel sheet and an intermediate layer formed between the insulating layer and the iron matrix surface of the steel sheet, and the intermediate layer contains at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb, and B1. Rcconn / zznz / E / YiAi 5. A method for producing a non-oriented electrical steel sheet comprising subjecting a steel plate to hot rolling, cold rolling, and finish annealing, characterized in that the steel plate has a component composition comprising C: not more than 0.0050% by mass, Si: 2.8 to 6.5% by mass, Mn: 0.1 to 2.0% by mass, P: not more than 0.10% by mass, S: not more than 0.0050% by mass, Al: 0.3 to 2.0% by mass, N: not more than 0.0050% by mass, Zn: 0.0005 to 0.0050% by mass, Ti: not more than 0.0030% by mass, Nb: not more than 0.0030% by mass, O: not more than 0.0050% by mass, the remainder being Fe and unavoidable impurities, and a coating layer containing At least one selected element of Sn, Sb, P, S, Se, As, Te, B, Pb and B1 is formed on the surface of the steel sheet after finishing annealing.

6. The method for producing a non-oriented electrical steel sheet according to claim 5, wherein the steel sheet contains at least one composition group selected from the following Groups A to D: Group A: one or two selected from Sn: 0.005 to 0.20% by mass and Sb: 0.005 to 0.20% by mass; Group B: one or two or more selected from Ca, Mg and REM between 0.0005 and 0.020% by mass in total; Group C: one or two or more selected from Cu, Ni, Cr and Co in 0.01 to 1.0% by mass in total; and Group D: one or two selected from Mo: 0.001 to 0.1% by mass and W: 0.001 to 0.1% by mass.

7. The method for producing a non-oriented electrical steel sheet according to claim 5 or 6, wherein a coating agent containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb and B1 is applied to an iron matrix surface of the steel sheet after finish annealing to form, as a coating layer, an insulating coating with nitriding suppression capability.

8. The method for producing a non-oriented electrical steel sheet according to claim 5 or 6, wherein a treatment agent containing at least one element selected from Sn, Sb, P, S, Se, As, Te, B, Pb and B1 is applied to an iron matrix surface of the steel sheet after finish annealing to form, as a coating layer, an intermediate layer with nitriding suppression capability and over the intermediate layer an insulating coating is formed which does not contain the elements Rcconn / zznz / E / YiAi described above.

9. A motor core comprising a rotor core formed by laminating core material processed from any of the non-oriented electrical steel sheets according to claims 1 to 4 into a core shape and a stator core formed by laminating core material processed from the same non-oriented electrical steel sheet as the former into a core shape and performing a stress-relief annealing thereon, wherein the steel sheet forming the stator core has an iron loss Wio / soo (W / kg) satisfying the following equation (1) with respect to the sheet thickness t (mm): W10 / 8OO 15 + 80 x t.....(1) and the N present as AIN (N as AIN) in a layer from a lateral surface to 1 / 20 of the steel sheet thickness after stress-relief annealing is not greater than 0.0100% by mass.

10. A method for producing a motor core comprising a stator core and a rotor core comprising processing a non-oriented electrical steel sheet produced by any of the methods according to claims 5 to 8 into a core shape, rolling the core-shaped material to assemble a stator core and a rotor core, subjecting the stator core to stress-relief annealing, wherein the stress-relief annealing is performed under an atmosphere comprising a gas selected from nitrogen, hydrogen, and a rare gas or a mixture of two or more of the gases at an immersion temperature of 800 to 950°C for an immersion time of 0.5 to 3.0 h.

11. A method for producing a motor core according to claim 10, wherein the steel sheet after stress-relief annealing has an iron loss Ww / soo (W / kg) satisfying the following equation (1) with respect to the sheet thickness t (mm): W10 / 800 < 15 + 80 x t.....(1) and the N present as AIN (N as AIN) in a layer from a side surface to 1 / 20 of the thickness of the steel sheet after stress-relief annealing is not greater than 0.0100% by mass.