Rotating electrical machines, electrical steel sheets with non-oriented structure, multi-layer core, rotating electrical machine manufacturing methods and multi-layer core manufacturing methods.

Abstract

The invention relates to a rotating electric machine, which includes a stator, rotor, and a stator and rotor housing, where A is the directional intensity {111} <211> of the base steel plate of the electrical engineering steel plate with non-oriented structure included in the stator is less than 15, B is the oriented strength {111} <211> The base steel plate of the electrical engineering steel plate with an unoriented structure included in the rotor is in the range from 2 to 30, A and B satisfy the relationship B / A > 1.0, C is the oriented strength {411} <011> The base steel plate of the electrical engineering steel plate with an unoriented structure included in the stator ranges from 2 to 50, D is the oriented strength {411} <011> The base steel plate of the electrical engineering steel plate with an unoriented structure included in the rotor ranges from 1 to 40, and C and D satisfy the C / D relationship > 1.0.

Description

Rotating electric machine, non-oriented electrical steel sheet, laminated core, manufacturing method of rotating electric machine, and manufacturing method of laminated core

[0001] The present invention relates to a rotating electric machine, a non-oriented electrical steel sheet, a laminated core, and a method for manufacturing a rotating electric machine and a method for manufacturing a laminated core. This application claims priority based on Japanese Patent Application No. 2021-187952, filed on November 18, 2021, the contents of which are incorporated herein by reference.

[0002] In this specification, the non-oriented electromagnetic steel sheets before lamination that make up the stator core are referred to as the stator core material, the non-oriented electromagnetic steel sheets before lamination that make up the rotor core are referred to as the rotor core material, and the combination of the stator core and rotor core is sometimes referred to as the motor core.

[0003] Electrical steel sheets, particularly non-oriented electrical steel sheets, are used as iron core materials for rotating electrical machines. For example, rotating electrical machines are used as drive motors installed in hybrid vehicles, fuel cell vehicles, electric vehicles, etc. Future vehicle drive motors are required to have both low noise and high torque. Motor noise is mainly caused by uneven magnetic attraction. Furthermore, if the gap between the stator and rotor becomes uneven due to rotor eccentricity, the magnetic attraction force also becomes uneven, causing increased motor noise.

[0004] Patent Document 1 proposes a non-oriented electrical steel sheet with small magnetic anisotropy and high magnetic flux density that is effective in improving the efficiency of an actual motor and reducing noise during rotation. In a motor, magnetic flux flows between the stator and rotor sections through an air gap, and the interaction of this magnetic flux generates torque in the rotor. The stronger the anisotropy of the electrical steel sheet used as the stator material, i.e., the greater the difference in magnetic properties in the in-plane direction of the sheet, the greater the difference in torque at each rotational position of the rotor. It describes how this torque fluctuation during rotation causes rotational irregularities and affects noise.

[0005] Japanese Patent Application Publication No. 2001-49402

[0006] The present invention aims to provide a rotating electric machine that achieves both the low noise and high torque required for automobile drive motors, a non-oriented electrical steel sheet suitable as a material for the rotor or stator of such a rotating electric machine, a laminated core made by laminating non-oriented electrical steel sheets and suitable for use in the stator or rotor of a rotating electric machine, and methods for manufacturing these.

[0007] Motor noise is mainly caused by uneven magnetic attraction between the stator and rotor. When the gap between the stator and rotor becomes uneven due to rotor eccentricity or other reasons, the magnetic attraction also becomes uneven, causing increased noise.

[0008] It has been found that the {111}<uvw> orientation of non-oriented electrical steel sheets has a small anisotropy in the in-plane Young's modulus (the proportional coefficient between elongation and stress in the elastic deformation region). Based on this finding, the inventors conducted further studies and found that using electrical steel sheets (non-oriented electrical steel sheets) enriched in the {111}<211> orientation as the rotor core material of a PM (Permanent Magnet) motor suppresses the anisotropy of the elongation deformation of the steel sheets of the rotor core material due to the centrifugal force during rotor rotation, thereby reducing noise. Generally, the {111}<211> orientation is difficult to magnetize, so its use as a motor core material is avoided. However, for the rotor core material of a PM motor, which ensures magnetization with a permanent magnet, the use of electrical steel sheets enriched in the {111}<211> orientation does not pose a significant disadvantage. On the other hand, it is disadvantageous to use an electromagnetic steel sheet enriched in the {111}<211> orientation as the stator core material, which ensures the magnetization that generates motor torque through the magnetization of the core material. Therefore, the inventors decided to use an electromagnetic steel sheet (non-oriented electromagnetic steel sheet) enriched in the {411}<011> orientation, which has excellent magnetic properties, as the stator core material, and discovered that by using electromagnetic steel sheets enriched in different orientations for the rotor core material and the stator core material, it is possible to achieve both low noise and high torque in a rotating electric machine obtained using these materials. Here, {lmn}<uvw> represents the crystal orientation. {lmn} refers to the Miller indices parallel to the normal direction of the rolling surface, and <uvw> refers to the Miller indices parallel to the rolling direction in the electromagnetic steel sheet manufacturing process. Furthermore, since the present invention is intended to control the rotational torque fluctuations caused by the in-plane anisotropy of the properties of the electrical steel sheet, the strength of the orientation of the grains in the rolling direction is also included in the definition.

[0009] In order to solve the above problems, the present invention provides the following: [1] A rotating electric machine according to one aspect of the present invention includes a stator, a rotor, and a housing that houses the stator and the rotor, wherein the base steel sheet of a non-oriented electrical steel sheet included in the stator has a {111}<211> orientation strength A of less than 15, the base steel sheet of a non-oriented electrical steel sheet included in the rotor has a {111}<211> orientation strength B of 2 to 30, and A and B satisfy the relationship B / A > 1.0, and the base steel sheet of the non-oriented electrical steel sheet included in the stator has a {111}<211> orientation strength B of 2 to 30. The {411}<011> orientation strength C of the base steel sheet of the non-oriented electrical steel sheet included in the rotor is 2 to 50, the {411}<011> orientation strength D of the base steel sheet of the non-oriented electrical steel sheet included in the rotor is 1 to 40, and the C and the D satisfy the relationship C / D>1.0, and the base steel sheets of the non-oriented electrical steel sheets included in the rotor and the stator each contain, in mass %, C: 0.0100% or less, Si: 0.5000 to 4.0000%, sol. The chemical composition includes Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more elements selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: 0.1000 to 5.0000% in total, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 to 0.4000%, Ti: 0 to 0.1000%, Nb: 0 to 0.1000%, Zr: 0 to 0.1000%, V: 0 to 0.1000%, and the balance being Fe and impurities. [2] In the rotating electric machine described in [1] above, in the non-oriented electrical steel sheet included in the rotor, B and E, which is the strength of the {111}<011> orientation, may satisfy the relationship of B / E > 1.0. [3] In the rotating electric machine described in [1] or [2] above, in the non-oriented electrical steel sheet included in the stator, C and F, which is the strength of the {100}<011> orientation, may satisfy the relationship of C / F > 1.0.[4] In the rotating electric machine according to any one of [1] to [3] above, the difference in the total of the Si content, Mn content, and sol. Al content of the base steel sheet between the non-oriented electrical steel sheet included in the stator and the non-oriented electrical steel sheet included in the rotor may be within 0.20 mass%, and the average grain size of the non-oriented electrical steel sheet included in the stator may be larger than the average grain size of the non-oriented electrical steel sheet included in the rotor. [5] In the rotating electric machine according to any one of [1] to [4] above, the Si content, Ti content, and Nb content of the base steel sheet of the non-oriented electrical steel sheet included in the stator may be, in mass%, respectively. ｓ , Ti ｓ , Nb ｓ The Si content, Ti content, and Nb content of the base steel sheet of the non-oriented electrical steel sheet included in the rotor are respectively set to Si ｒ , Ti ｒ , Nb ｒ When this is the case, Si ｓ / Si ｒ >1.0, Ti ｒ / Ti ｓ >1.0, Nb ｒ / Nb ｓ [6] The rotating electric machine according to any one of the above [1] to [5], wherein the base steel sheet of the non-oriented electrical steel sheet included in the stator has a Nb content, a Zr content, a Ti content, a V content, a C content, and a N content, in mass%, of Nb, Zr, Ti, V, C, and N, respectively. ｓ , Zr ｓ , Ti ｓ , V ｓ , C ｓ , N ｓ When 0≧Nb ｓ / 93+Zr ｓ / 91+Ti ｓ / 48+V ｓ / 51-(C ｓ / 12+N ｓ [7] In the rotating electric machine according to any one of the above [1] to [6], the Nb content, Zr content, Ti content, V content, C content, and N content of the base steel sheet of the non-oriented electrical steel sheet included in the rotor may be set to Nb, Zr, Ti, V, C, and N, respectively, in mass %. ｒ , Zr ｒ , Tiｒ , V ｒ , C ｒ , N ｒ When 0<Nb ｒ / 93+Zr ｒ / 91+Ti ｒ / 48+V ｒ / 51-(C ｒ / 12+N ｒ / 14) < 5.0 x 10 －３[8] A non-oriented electrical steel sheet according to another embodiment of the present invention includes a base steel sheet and an insulating coating formed on a surface of the base steel sheet, and the base steel sheet contains, in mass %, C: 0.0100% or less, Si: 0.5000 to 4.0000%, sol. Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more elements selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: 0.1000 to 5.0000% in total, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 up to 0.4000%, Ti: 0-0.1000%, Nb: 0-0.1000%, Zr: 0-0.1000%, V: 0-0.1000%, with the balance being Fe and impurities, and in the base steel sheet, the {111}<211> orientation intensity is less than 15 and the {411}<011> orientation intensity is 2 to 50. [9] A non-oriented electrical steel sheet according to another aspect of the present invention comprises a base steel sheet and an insulating coating formed on the surface of the base steel sheet, and the base steel sheet contains, in mass %, C: 0.0100% or less, Si: 0.5000-4.0000%, sol. Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: 0.1000 to 5.0000% in total, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 to The base steel sheet has a chemical composition comprising 0.4000%, Ti: 0-0.1000%, Nb: 0-0.1000%, Zr: 0-0.1000%, V: 0-0.1000%, and the balance being Fe and impurities, and the {111}<211> orientation intensity is 2-30 and the {411}<011> orientation intensity is 1-40.

[10] A laminated core according to another aspect of the present invention is formed by laminating the non-oriented electrical steel sheets according to the above item [8].

[11] A laminated core according to another aspect of the present invention is formed by laminating the non-oriented electrical steel sheets according to the above item [9].

[12] In the rotating electric machine according to any one of the above items [1] to [7], the non-oriented electrical steel sheets included in the stator may be steel sheets obtained by further subjecting the non-oriented electrical steel sheets included in the rotor to heat treatment at 600°C or higher.

[13] A method for manufacturing a laminated core according to another aspect of the present invention includes a step of processing and laminating the non-oriented electrical steel sheets described in [8] above.

[14] A method for manufacturing a laminated core according to another aspect of the present invention includes a step of processing and laminating the non-oriented electrical steel sheets described in [9] above.

[15] A method for manufacturing a rotating electric machine according to another aspect of the present invention includes a step of assembling the laminated core described in

[10] above and the laminated core described in

[11] above.

[0010] According to the above-described aspects of the present invention, it is possible to provide a rotating electric machine that achieves both low noise and high torque, which are required for automobile drive motors. It is also possible to provide a non-oriented electrical steel sheet suitable as a material for the rotor or stator of such a rotating electric machine. It is also possible to provide a laminated core made of laminated non-oriented electrical steel sheets suitable for use in the stator or rotor of a rotating electric machine. That is, the rotating electric machine according to the above-described aspects of the present invention uses an electrical steel sheet enriched in the {111}<211> orientation as the rotor core material, thereby reducing the anisotropy of the Young's modulus in the in-plane direction of the sheet and suppressing the anisotropy of the radial deformation of the rotor core material due to centrifugal force during rotor rotation. This allows the gap between the stator and rotor to be constant, thereby suppressing motor noise. Furthermore, it is also possible to increase motor torque by using an electrical steel sheet enriched in the {411}<011> orientation as the stator core material. Therefore, the rotating electric machine according to the above-described aspects of the present invention can achieve both low noise and high torque.

[0011] FIG. 2 is a partial plan view of a motor used in the embodiment.

[0012] Below, we will explain a rotating electric machine according to one embodiment of the present invention (a rotating electric machine according to this embodiment), a non-oriented electrical steel sheet according to one embodiment of the present invention (a non-oriented electrical steel sheet according to this embodiment), and a laminated core according to one embodiment of the present invention (a laminated core according to this embodiment), as well as methods for manufacturing these. Unless otherwise specified, the notation "a to b" for the numerical values ​​a and b means "a or more and b or less." In such notation, when a unit is assigned only to the numerical value b, the unit also applies to the numerical value a.

[0013] [Rotating Electric Machine] [Non-oriented Electrical Steel Sheet] The rotating electric machine according to this embodiment has the following configuration. a rotor; and a housing that houses the stator and the rotor, wherein A, which is the {111}<211> orientation strength of a base steel sheet of a non-oriented electrical steel sheet included in the stator, is less than 15, B, which is the {111}<211> orientation strength of a base steel sheet of a non-oriented electrical steel sheet included in the rotor, is 2 to 30, and A and B satisfy the relationship B / A > 1.0, C, which is the {411}<011> orientation strength of a base steel sheet of a non-oriented electrical steel sheet included in the stator, is 2 to 50, D, which is the {411}<011> orientation strength of a base steel sheet of a non-oriented electrical steel sheet included in the rotor, is 1 to 40, and C and D satisfy the relationship C / D > 1.0, and the base steel sheets of the non-oriented electrical steel sheets included in the rotor and the stator are each The chemical composition includes, in mass%, C: 0.0100% or less, Si: 0.5000 to 4.0000%, sol. Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more elements selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: 0.1000 to 5.0000% in total, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 to 0.4000%, Ti: 0 to 0.1000%, Nb: 0 to 0.1000%, Zr: 0 to 0.1000%, V: 0 to 0.1000%, and the balance being Fe and impurities. Of these, the non-oriented electromagnetic steel sheets contained in the rotor (as the rotor core material) and the non-oriented electromagnetic steel sheets contained in the stator (as the stator core material) are each non-oriented electromagnetic steel sheets according to this embodiment.

[0014] The rotating electric machine according to this embodiment has at least a stator, a rotor, and a housing that houses the stator and rotor. The shapes and configurations of the stator, rotor, and housing are not particularly limited, and may have ordinary shapes and configurations.

[0015] <Non-oriented electrical steel sheet> The non-oriented electrical steel sheet according to this embodiment includes a base steel sheet and an insulating coating formed on the surface of the base steel sheet. Among these, the non-oriented electrical steel sheet according to this embodiment is particularly characterized by the chemical composition and texture (orientation strength in each orientation) of the base steel sheet.

[0016] [Orientation Strength of Each Orientation in Base Steel Sheet] The {111}<211> orientation strength of the base steel sheet of a non-oriented electrical steel sheet mainly represents the integrated strength of the {111} orientation, which has a relatively small anisotropy of Young's modulus in the in-plane direction. Considering the reduction of the anisotropy in the in-plane direction of the sheet due to the crystal orientation, it is considered ideal to have a completely random texture. Alternatively, even if it is not completely random, it is considered preferable to strongly integrate in a specific plane orientation and randomize the integration in the in-plane direction related to that plane orientation. For example, it is considered preferable to make the integration strength for v and w uniform in {100}<0vw>, or to make the change in the integration strength in the sheet plane small and random even in the {111} orientation. However, in electrical steel sheets manufactured through general casting, rolling, and annealing (heat treatment), considerable integration in a specific orientation in the base steel sheet is unavoidable, making it difficult to achieve the ideal randomization described above. Given this background, in the non-oriented electrical steel sheet (non-oriented electrical steel sheet according to the present embodiment) included in the rotor and stator of the rotating electrical machine according to the present embodiment, the {111}<211> orientation strength of the base steel sheet is an orientation that must be reliably controlled as intended in general electrical steel sheets, and is a very effective indicator for achieving suppression of the anisotropy of Young's modulus in the sheet's in-plane direction. Furthermore, the {111}<211> orientation strength is also an effective indicator for evaluating the magnetic properties of the stator core material, and in the present embodiment, this orientation is used as a specification for achieving the desired effect. Furthermore, the {411}<011> orientation strength of the base steel sheet of the electrical steel sheet mainly indicates that the easy axis of magnetization is close to the in-plane direction, thereby resulting in excellent magnetic properties. Here, the easy axis of magnetization is the direction in which magnetization is easiest among the magnetic anisotropy of the crystal, and in a bcc structure crystal, it refers to the ridge direction (

[100] ,

[010] , or

[001] direction). Therefore, in this embodiment, this orientation is also used as one of the definitions for obtaining the effect. In this specification, the orientation strength of the base steel sheet of the electrical steel sheet may be simply expressed as the orientation strength of the electrical steel sheet (non-oriented electrical steel sheet), but even in this case, it means the orientation strength of the base steel sheet.

[0017] In this specification, "orientation intensity" indicates how many times the diffraction intensity is compared to when the crystal orientation is random. That is, for example, {111}<211> orientation intensity indicates how many times the diffraction intensity of the {111}<211> orientation measured by EBSD is compared to when the crystal orientation is random. There are various methods for measuring crystal orientation intensity, but the {111}<211> orientation intensity and {411}<011> orientation intensity are measured by first polishing the rolled surface of the base steel sheet of the non-oriented electrical steel sheet that is the stator core material and rotor core material so that the center of the sheet thickness is exposed, and then measuring the polished surface by EBSD (Electron Backscatter Diffraction) at 960,000 μm. 2 Observation was carried out on the above areas. The total area observed was 960,000 μm 2 It is sufficient to observe an area of ​​800 μm × 1200 μm or more, for example. If the area does not fit within the field of view of the measurement magnification, it is possible to perform the measurement in several locations divided into several small sections, for example, an area of ​​200 μm × 600 μm or more may be observed at eight or more locations. The step interval during measurement is preferably 1 μm. The upper limit of the step interval is 1 / 10 of the average crystal grain size. The {111}<211> orientation intensity and {411}<011> orientation intensity are determined from the EBSD observation data.

[0018] The procedure for determining the {111}<211> orientation intensity and the {411}<011> orientation intensity from the EBSD observation data is as follows. 2 The above range is observed, and the number of crystal grains observed is at least 100. The observed data is analyzed using OIM Analysis software (manufactured by TSL) to create an ODF (Orientation Distribution Function), and the {111}<211> orientation intensity and {411}<011> orientation intensity are calculated from the ODF value.

[0019] In the rotating electric machine according to this embodiment, the {111}<211> orientation strength (A) of the base steel sheet of the non-oriented electrical steel sheet that is the iron core material of the stator is in the range of less than 15. If the {111}<211> orientation strength (A) exceeds 15, the magnetic properties deteriorate. The {111}<211> orientation strength (A) is preferably in the range of 1 to 3.

[0020] In the rotating electric machine according to this embodiment, the {111}<211> orientation strength (B) of the base steel sheet of the non-oriented electrical steel sheet that is the iron core material of the rotor is in the range of 2 to 30. If the {111}<211> orientation strength (B) is less than 2, the in-plane anisotropy of the Young's modulus of the sheet increases, resulting in increased noise during rotation. On the other hand, if the {111}<211> orientation strength (B) exceeds 30, the magnetic permeability decreases, resulting in reduced motor efficiency. The orientation strength (B) is preferably in the range of 10 to 30.

[0021] In the rotating electric machine according to this embodiment, the non-oriented electrical steel sheet used as the stator core material and the non-oriented electrical steel sheet used as the rotor core material each must have the {111}<211> orientation strength of the base steel sheet within the above-mentioned range, and the orientation strengths A and B of each steel sheet must satisfy the relationship B / A > 1.0. When A and B satisfy the relationship B / A > 1.0, it is possible to reduce losses generated in the stator core, which is susceptible to the magnetic properties of the core material, and reduce noise generated in the rotor core, which is susceptible to deformation due to centrifugal force associated with rotation, thereby improving motor characteristics. Preferably, B / A > 1.1, and more preferably B / A > 1.2. Conversely, when A and B satisfy the relationship B / A ≦ 1.0, an electrical steel sheet that is unfavorable in terms of deformation due to centrifugal force is used as the rotor core material, and an electrical steel sheet that is unfavorable in terms of magnetic properties is used as the stator core material, resulting in increased motor losses.

[0022] Furthermore, in the rotating electric machine according to this embodiment, the {411}<011> orientation strength (C) of the base steel sheet of the non-oriented electrical steel sheet that is the iron core material of the stator is in the range of 2 to 50. If the orientation strength (C) is less than 2, the magnetic properties deteriorate, and the motor characteristics become poor. On the other hand, if the {411}<011> orientation strength (C) exceeds 50, manufacturing becomes difficult. The orientation strength (C) range is preferably 5 to 30.

[0023] In the rotating electric machine according to this embodiment, the {411}<011> orientation strength (D) of the base steel sheet of the non-oriented electrical steel sheet that is the rotor core material is 1 to 40. If the {411}<011> orientation strength (D) exceeds 40, the in-plane anisotropy of the Young's modulus of the sheet becomes strong, resulting in increased noise. On the other hand, if the orientation strength (D) is less than 1, heat is likely to be generated inside the rotor, the permanent magnets may be demagnetized, and the motor characteristics may deteriorate. The {411}<011> orientation strength (D) is preferably in the range of 3 to 20.

[0024] In the rotating electric machine according to this embodiment, the stator core material and the rotor core material (non-oriented electrical steel sheet) each require a base steel sheet having the above-described {411}<011> orientation strength range, and the orientation strengths C and D, which satisfy the relationship C / D > 1.0. When C and D satisfy the relationship C / D > 1.0, both improvement of the magnetic properties of the stator core, which is easily affected by the magnetic properties of the core material, and reduction of noise generated by the rotor core, which is easily affected by deformation due to centrifugal force during rotation, can be achieved. Preferably, C / D > 1.1, and more preferably C / D > 1.2. Conversely, when C and D satisfy the relationship C / D ≦ 1.0, an electrical steel sheet that is unfavorable in terms of deformation due to centrifugal force is used as the rotor core material, and an electrical steel sheet that is unfavorable in terms of magnetic properties is used as the stator core material, resulting in increased motor loss.

[0025] Here, the orientation strength of the base steel sheet of the iron core material (non-oriented electrical steel sheet) for the stator and rotor will be explained. The {111}<211> orientation strength and {411}<011> orientation strength defined in this embodiment are roughly in a trade-off relationship. For example, in terms of characteristics, the {111}<211> orientation is an unfavorable orientation for magnetic properties, while the {411}<011> orientation is favorable. For this reason, in this embodiment, the non-oriented electrical steel sheet that is the iron core material for the stator is controlled to weaken the {111}<211> orientation strength while simultaneously strengthening the {411}<011> orientation strength. From a metallurgical perspective, changes in texture during the steel sheet manufacturing process by cold rolling and annealing (recrystallization) are observed, for example, depending on changes in the cold rolling reduction rate and annealing temperature. In this context, in this embodiment, for example, in a non-oriented electrical steel sheet serving as a stator core material, the {111}<211> orientation strength (A) of the base steel sheet is weakened and the {411}<011> orientation strength (C) is increased. As a result, A / C<1.0 is likely to be satisfied for the stator core material. From the other perspective, it is preferable for a stator core material to satisfy A / C<1.0. More preferably, A / C<0.8, and even more preferably, A / C<0.6.

[0026] Similarly, in the case of non-oriented electrical steel sheets used as rotor core materials, controlling the {111}<211> orientation strength (B) of the base steel sheet to be stronger and the {411}<011> orientation strength (D) to be weaker makes it easier for the rotor core material to satisfy B / D > 1.0. Looking at it from the other way around, it is preferable for the rotor core material to satisfy B / D > 1.0. More preferably, B / D > 1.5, and even more preferably, B / D > 2.0.

[0027] However, just to be clear, the above-mentioned "trade-off relationship" does not necessarily mean that it is always realized in principle, but rather means that a trade-off relationship often exists, assuming the steel sheet manufacturing process involving cold rolling and annealing (recrystallization) and the magnetic properties required of electrical steel sheets. In other words, this does not deny the phenomenon in which, for example, the {111}<211> orientation and the {411}<011> orientation simultaneously increase or decrease.

[0028] The reason why motor noise is reduced when the {111}<211> orientation strengths (A), (B) and {411}<011> orientation strengths (C), (D) of the base steel sheets for the stator core material and the rotor core material satisfy the relationships B / A > 1.0 and C / D > 1.0, respectively, is thought to be as follows: As mentioned above, the {411}<011> orientation is a favorable orientation for magnetic properties, and therefore, conventional electrical steel sheets for motors have been controlled to increase the strength of this orientation. However, because this orientation has large in-plane anisotropy of Young's modulus, if an electrical steel sheet with a high {411}<011> orientation strength is used as the rotor core material, it will deform anisotropically with respect to the rotating shaft during rotation, generating vibration and increasing noise. As in the rotating electric machine according to this embodiment, non-oriented electrical steel sheets with high strength in the {411}<011> orientation are used only as the iron core material for the stator, and non-oriented electrical steel sheets with relatively low strength in the {411}<011> orientation and increased strength in the {111}<211> orientation, which have small in-plane anisotropy of Young's modulus, are used for the iron core material for the rotor. By using these non-oriented electrical steel sheets, deformation during rotation is isotropic with respect to the rotating shaft, which suppresses vibration and reduces noise.

[0029] The non-oriented electrical steel sheet that is the iron core material of the rotor of the rotating electric machine according to this embodiment preferably further has a {111}<211> orientation strength (B) and a {111}<011> orientation strength (E) that satisfy the relationship B / E>1.0.

[0030] In this embodiment, the {411}<011> orientation, which has a large in-plane anisotropy, and the {111}<211> orientation, which has a small in-plane anisotropy, are controlled. However, with regard to the {111} orientation, in addition to the {111}<211> orientation, the {111}<011> orientation is likely to develop. Considering the overall influence of these orientations on the in-plane anisotropy, the {111}<011> orientation, which has the same in-plane <011> orientation as the {410}<011> orientation, is less advantageous in reducing the overall in-plane anisotropy than the {111}<211> orientation. From this perspective, in the rotating electric machine according to this embodiment, it is preferable that the non-oriented electrical steel sheet included in the rotor has a B / E ratio of > 1.0. More preferably, it is > 1.5, and even more preferably, it is > 2.0.

[0031] In the rotating electric machine according to this embodiment, the non-oriented electrical steel sheet used as the stator core material preferably satisfies the relationship C / F > 1.0 between the {411}<011> orientation strength (C) of the base steel sheet and the {100}<011> orientation strength (F) of the base steel sheet. The {100}<011> orientation increases iron loss significantly with compressive stress. While there are several methods for fixing the stator, most of them apply compressive stress to the stator core. Therefore, it is better to increase the {411}<011> orientation, which has low compressive stress sensitivity. A more preferable C / F ratio is C / F > 1.5, and even more preferable C / F > 2.0.

[0032] [Chemical Composition] The chemical compositions of the base steel sheets of the non-oriented electrical steel sheet used as the stator core material and the non-oriented electrical steel sheet used as the rotor core material of the rotating electric machine according to this embodiment preferably have the following chemical compositions, so that the stator core material and rotor core material that satisfy the strength requirements in each orientation can be obtained from the manufactured non-oriented electrical steel sheet. In the explanation of the chemical composition, "%" means "mass %." In the rotating electric machine according to this embodiment, the chemical compositions of the base steel sheets of the non-oriented electrical steel sheet used as the stator core material and the non-oriented electrical steel sheet used as the rotor core material may be the same or, as will be described later, may be different.

[0033] (C: 0.0100% or less) C is an element that increases iron loss and causes magnetic aging. Therefore, the lower the C content, the better. This phenomenon is significant when the C content exceeds 0.0100%. For this reason, the C content is set to 0.0100% or less. Reducing the C content also contributes to uniformly improving the magnetic properties in all directions within the plate surface. There is no particular lower limit for the C content, but taking into account the cost of decarburization treatment during refining, it is preferable to set it to 0.0005% or more.

[0034] (Si: 0.5000 to 4.0000%) Si is an element that increases electrical resistance, reduces eddy current loss, reduces iron loss, and increases the yield ratio, thereby improving punching workability into iron cores. If the Si content is less than 0.5000%, these effects cannot be fully achieved. Therefore, the Si content is set to 0.5000% or more. The Si content is preferably 0.9000% or more, and more preferably 1.5000% or more. On the other hand, if the Si content exceeds 4.0000%, the magnetic flux density decreases, punching workability decreases due to an excessive increase in hardness, and cold rolling becomes difficult. Therefore, the Si content is set to 4.0000% or less. In addition, Si is an element contained in relatively large amounts in electrical steel sheets, and has a significant effect on the {111}<211> orientation and {411}<011> orientation after cold rolling and recrystallization annealing, which are mainly controlled in this embodiment. In low-Si steel, the {111}<211> orientation is likely to develop, while the {411}<011> orientation is likely to be suppressed. Therefore, it is preferable that the non-oriented electrical steel sheet used for the stator core material has a higher Si content in the base steel sheet than the non-oriented electrical steel sheet used for the rotor core material. In particular, the presence or absence of transformation due to the Si content during the steel sheet manufacturing process can be utilized to control the texture. It is even more preferable that the steel sheet used for the stator core material has a high-Si, non-transformation chemical composition and the steel sheet used for the rotor core material has a low-Si, transformation chemical composition.

[0035] (sol. Al: 0.0001 to 1.0000%) Al is an element that increases electrical resistance, reduces eddy current loss, and reduces iron loss. Al also contributes to improving the relative magnitude of magnetic flux density B50 relative to saturation magnetic flux density. If the sol. Al (acid-soluble Al) content is less than 0.0001%, these effects cannot be fully obtained. Al also has the effect of promoting desulfurization in steelmaking. Therefore, the sol. Al content is set to 0.0001% or more. On the other hand, if the sol. Al content exceeds 1.0000%, the magnetic flux density decreases, the yield ratio decreases, and punching workability decreases. Therefore, the sol. Al content is set to 1.0000% or less.

[0036] Here, the magnetic flux density B50 is the magnetic flux density in a magnetic field of 5000 A / m.

[0037] (S: 0.0100% or less) S is not an essential element, but is contained in steel as an impurity, for example. S precipitates as fine MnS, inhibiting recrystallization and grain growth during annealing. Therefore, the lower the S content, the better. Such an increase in iron loss and a decrease in magnetic flux density due to the inhibition of recrystallization and grain growth are significant when the S content exceeds 0.0100%. For this reason, the S content is set to 0.0100% or less. There is no particular lower limit for the S content, but it is preferably set to 0.0003% or more, taking into account the cost of desulfurization treatment during refining.

[0038] (N: 0.0100% or less) Like C, N is an element that deteriorates magnetic properties. Therefore, the lower the N content, the better. If the N content exceeds 0.0100%, the adverse effects become significant, so the N content is set to 0.0100% or less. There is no particular lower limit for the N content, but in consideration of the cost of denitrification treatment during refining, it is preferably set to 0.0010% or more.

[0039] (One or more elements selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: 0.1000 to 5.0000% in total) At least one or more of Mn, Ni, Co, Pt, Pb, Cu, and Au must be contained in a total amount of 0.1000% or more. From the viewpoint of increasing electrical resistance and reducing iron loss, the content of at least one or more of these elements is more preferably 0.2000% or more in total. More preferably, the content is 1.0000% or more in total. On the other hand, if the content of these elements exceeds 5.0000% in total, costs may increase and the magnetic flux density may decrease. Therefore, the content of at least one of these elements is set to 5.0000% or less in total. Preferably, it is 4.0000% or less.

[0040] (Cr: 0 to 2.0000%) Cr is an element that improves corrosion resistance, high-frequency characteristics, and texture. Cr does not need to be contained, and the lower limit of the Cr content is 0%. The effects of Cr inclusion can be obtained even with a small amount, but to ensure the effects of inclusion, the content is preferably 0.0010% or more, more preferably 0.0020% or more, even more preferably 0.0200% or more, and even more preferably 0.1000% or more. On the other hand, if the Cr content exceeds 2.0000%, Cr forms carbonitrides, which refine the crystal grain size and increase iron loss. Therefore, the Cr content is set to 2.0000% or less.

[0041] (Sn: 0-0.4000%, Sb: 0-0.4000%, P: 0-0.4000%) Sn and Sb are elements that improve the texture after cold rolling and recrystallization, thereby increasing the magnetic flux density. Therefore, these elements can be added as needed. To improve magnetic properties, it is preferable to contain one or more elements selected from the group consisting of 0.0200-0.4000% Sn, 0.0200-0.4000% Sb, and 0.0200-0.4000% P. On the other hand, excessive Sn and Sb embrittle the steel. Therefore, the Sn content and Sb content are both set to 0.4000% or less. Furthermore, P can be added to ensure the hardness of the steel sheet after recrystallization, but excessive P content can embrittle the steel. Therefore, the P content is set to 0.4000% or less.

[0042] (Ti: 0 to 0.1000%, Nb: 0 to 0.1000%) Ti and Nb are elements that fix and reduce solute C and N as precipitates, thereby changing the texture after cold rolling and recrystallization. Their inclusion increases the strength of the {111}<211> orientation and decreases the strength of the {411}<011> orientation. To fully achieve this effect, it is preferable to add Ti and Nb in amounts equivalent to or greater than the C and N contents. Generally, Ti and Nb are added in amounts of 0.0200% or more, and more preferably 0.0400% or more, respectively. However, the Ti and Nb contents are both limited to 0.1000% or less. As described above, their inclusion increases the strength of the {111}<211> orientation and decreases the strength of the {411}<011> orientation. Therefore, it is preferable to add Ti and Nb in larger amounts to the non-oriented electrical steel sheet used as the rotor core material. However, as described below, when Ti and / or Nb are contained in an amount of 0.0100% or more, sufficient properties cannot be obtained in the final annealing step unless the temperature rise rate in the final annealing is increased to 100°C / s or more. Failure to achieve such a temperature rise rate is undesirable because the {411}<011> orientation does not develop. In other words, the inclusion of Ti and / or Nb reduces manufacturability. Therefore, from this perspective, it is preferable that the Ti content be less than 0.0100% and the Nb content be less than 0.0100%. More preferably, the total of the Ti content, Nb content, V content, and Zr content, which will be described later, is less than 0.0100%.

[0043] Zr: 0 to 0.1000% V: 0 to 0.1000% In addition to the above elements, the chemical composition of the base steel sheet of the non-oriented electrical steel sheet according to this embodiment may further contain V and / or Zr as optional elements. Zr and V are both elements that have the effect of suppressing recrystallization, increasing the strength of the {111}<211> orientation, and decreasing the strength of the {411}<011> orientation. To achieve this effect, the Zr content and V content are each preferably 0.0100% or more. On the other hand, if the Zr content or V content exceeds 0.1000%, the steel becomes brittle. Therefore, the Zr content and V content are both set to 0.1000% or less. Preferably, they are 0.0500% or less, more preferably less than 0.0100%.

[0044] In the rotating electric machine according to this embodiment, the Nb content, Zr content, Ti content, V content, C content, and N content in mass % of the base steel sheet of the non-oriented electrical steel sheet included in the stator are ｓ , Zr ｓ , Ti ｓ , V ｓ , C ｓ , N ｓ When 0≧Nb ｓ / 93+Zr ｓ / 91+Ti ｓ / 48+V ｓ / 51-(C ｓ / 12+N ｓ / 14) is preferably satisfied. In this case, the effect of increasing the {411}<011> orientation strength is obtained. The lower limit is not particularly limited, but for example, Nb ｓ / 93+Zr ｓ / 91+Ti ｓ / 48+V ｓ / 51-(C ｓ / 12+N ｓ / 14) ≧-1.55×10 －３ The Nb content, Zr content, Ti content, V content, C content, and N content in mass % of the base steel sheet of the non-oriented electrical steel sheet included in the rotor may be set to Nb ｒ , Zr ｒ , Ti ｒ , V ｒ , C ｒ , N ｒ When 0<Nb ｒ / 93+Zr ｒ / 91+Ti ｒ / 48+V ｒ / 51-(C ｒ / 12+N ｒ / 14) < 5.0 x 10 －３ In this case, the effect of increasing the {111}<211> orientation strength can be obtained.

[0045] The remainder of the chemical composition other than those described above is Fe and impurities. In this embodiment, impurities refer to elements that are mixed in from raw materials or during the manufacturing process and do not clearly affect the characteristics of the rotating electric machine according to this embodiment. In addition to the elements described above, examples of impurities include B, O, Mg, Ca, Nd, Bi, W, Mo, Nb, and Y. The content of each of these elements is preferably 0.10% or less, for example. Furthermore, the total content of all impurities is preferably 5.00% or less, and more preferably 1.00% or less.

[0046] In the rotating electric machine according to this embodiment, the chemical composition of the base steel sheet of the non-oriented electrical steel sheet included in the stator and the chemical composition of the base steel sheet of the non-oriented electrical steel sheet included in the rotor may be the same, but considering the above effects, the Si content, Ti content, and Nb content of the base steel sheet of the non-oriented electrical steel sheet included in the stator are set to Si, Ti, and Nb in mass %, respectively. ｓ , Ti ｓ , Nb ｓ The Si content, Ti content, and Nb content of the base steel sheet of the non-oriented electrical steel sheet included in the rotor are respectively set to Si ｒ , Ti ｒ , Nb ｒ When this is the case, Si ｓ / Si ｒ >1.0, Ti ｒ / Ti ｓ >1.0, Nb ｒ / Nb ｓ It is preferable that Si satisfies any of the following conditions: ｓ / Si ｒ >1.0, Ti ｒ / Ti ｓ >1.0, Nb ｒ / Nb ｓ > 1.0, the effect of further reducing motor loss can be obtained.

[0047] In the rotating electric machine according to this embodiment, it is preferable that the difference in the total Si content, Mn content, and sol. Al content of the base steel sheet between the non-oriented electrical steel sheet included in the stator and the non-oriented electrical steel sheet included in the rotor is within 0.20 mass% (the absolute value of the difference is 0.20 mass% or less). This has the advantage of reducing work efficiency and costs, including when the stator and rotor are manufactured from the same material.

[0048] The chemical composition of the base steel sheet is determined using the following method. The entire surface of the test material is polished using a grinder or similar tool, washed with acetone, and then cut using a nibbler or similar tool to prepare a sample. C and S are measured using the combustion-infrared absorption method. N is measured using the inert gas fusion-thermal conductivity method. Sol-C Al is measured using acid dissolution-ICP atomic emission spectroscopy. O is measured using the inert gas fusion-non-dispersive infrared absorption method. Other elements are measured using ICP atomic emission spectroscopy. Here, the surface insulating coating may be removed by mechanical processing such as polishing, as described above, or chemically using hot alkali. Furthermore, when determining the chemical composition of the base steel sheet of the non-oriented electrical steel sheet contained in the stator or rotor of a rotating electrical machine, the rotating electrical machine can be disassembled, the non-oriented electrical steel sheet removed from the stator or rotor, and the chemical composition measured as described above. The detailed method for dismantling a rotating electric machine varies depending on the actual machine. To give an example, first, the rotating electric machine is removed from the machine in which it is housed. Then, a portion of the rotating electric machine's housing (case) is removed by machining. The stator and rotor are then separated. If the rotor has a permanent magnet, it is desirable to insert a spacer, such as a plastic sheet, between the stator and rotor due to magnetic attraction. The stator is then removed from the housing. Since the stator has windings, the windings are removed or partially cut. The topmost steel plate of the stator lamination or any steel plate damaged when the windings were cut is excluded, and samples are taken from other locations. In many cases, laminations are fastened together by crimping or welding. In the case of crimping, laminations can be separated by inserting a cutter blade into the gap between the laminated steel plates. In the case of welding, laminations can be separated by cutting the welded portion with a hand grinder. The rotor coil ends are often made of materials other than electromagnetic steel. Therefore, the rotor is machined using a non-magnetic blade near the longitudinal center to separate it into two pieces.Then, the laminations are peeled off in the same way as the stator described above.At this time, it is desirable to remove any areas affected by the machining.

[0049] [Average grain size of base steel sheet] In the rotating electric machine according to this embodiment, the average grain size of the base steel sheet of the non-oriented electrical steel sheet included in the stator is preferably larger than the average grain size of the base steel sheet of the non-oriented electrical steel sheet included in the rotor. In this case, the rotor has a higher strength in the {111}<211> orientation, and the stator has a higher strength in the {411}<011> orientation.

[0050] The average crystal grain size can be determined by the following method. The average crystal grain size can be determined by using the average value of crystal grain sizes measured by a sectioning method in the thickness direction and rolling direction of a longitudinal cross-sectional structural photograph. An optical microscope photograph can be used as this longitudinal cross-sectional structural photograph, and for example, a photograph taken at a magnification of 50 times can be used. In the thickness direction, it is preferable to count by drawing 20 or more line segments the entire length of the thickness. In the rolling direction, it is preferable to count by drawing 2 mm long line segments parallel to 1 / 4, 1 / 2, and 3 / 4 of the thickness. However, if an unrecrystallized region is included, the above method can be used to calculate only the recrystallized region.

[0051] Furthermore, in the rotating electric machine according to this embodiment, it is preferable that the non-oriented electrical steel sheet contained in the stator is a steel sheet obtained by further heat treating the non-oriented electrical steel sheet contained in the rotor at 600° C. or higher. In this case, the magnetic properties are improved by removing the strain introduced by processing, and the magnetic properties of the stator, which are easily affected by the magnetic properties of the iron core material, are improved, thereby improving the motor properties.

[0052] [Thickness of Base Steel Sheet] Next, the thickness of the base steel sheet of the non-oriented electrical steel sheet according to this embodiment will be described. The thickness of the base steel sheet of the non-oriented electrical steel sheet according to this embodiment is not necessarily limited, but is preferably 0.50 mm or less. If the thickness exceeds 0.50 mm, it is difficult to obtain excellent high-frequency iron loss. From the viewpoint of iron loss, a thinner sheet thickness is advantageous, so the thickness is preferably 0.35 mm or less, more preferably 0.20 mm or less, and even more preferably 0.15 mm or less. On the other hand, from the viewpoint of ease of production, the thickness of the base steel sheet of the non-oriented electrical steel sheet according to this embodiment is preferably 0.10 mm or more.

[0053] [Insulating Coating] In the non-oriented electrical steel sheet according to this embodiment, an insulating coating is formed on the surface of the base steel sheet. This insulating coating may be a known coating. For example, Al ２ O ３ An example of the coating is a coating made of:

[0054] <Laminated Core> The laminated core according to this embodiment includes a base steel plate and an insulating coating formed on the surface of the base steel plate. The base steel plate contains, in mass %, C: 0.0100% or less, Si: 0.5000 to 4.0000%, sol. Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: 0.1000 to 5.0000% in total, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 to 0.4000%, Ti: 0 to 0.1000%, Nb: 0 to 0.1000%, Zr: 0 to 0.1000%, V: 0 to 0.1000%, and the balance a laminated core (stator core) formed by laminating non-oriented electrical steel sheets (non-oriented electrical steel sheets according to the present embodiment) in which the non-oriented electrical steel sheets have a chemical composition consisting of Fe and impurities, the {111}<211> orientation strength is less than 15, and the {411}<011> orientation strength is 2 to 50, or a laminated core (stator core) comprising a base steel sheet and an insulating coating formed on the surface of the base steel sheet, the base steel sheet containing, in mass %, C: 0.0100% or less, Si: 0.5000 to 4.0000%, sol. Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more elements selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: 0.1000 to 5.0000% in total, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 to 0.4000%, Ti: 0 to 0.100 The present invention relates to a laminated core (rotor core) that does not include laminated non-oriented electrical steel sheets (non-oriented electrical steel sheets according to the present embodiment), and has a chemical composition containing 0%, Nb: 0-0.1000%, Zr: 0-0.1000%, V: 0-0.1000%, and the balance being Fe and impurities, and has a {111}<211> orientation strength of 2-30 and a {411}<011> orientation strength of 1-40. The laminated core is manufactured by punching, laminating, and bonding the non-oriented electrical steel sheets according to the present embodiment. The chemical composition and texture do not change during this process. Therefore, the non-oriented electrical steel sheets included in the laminated core have the same chemical composition and texture as the non-oriented electrical steel sheets according to the present embodiment described above.As can be seen from this, the chemical composition and texture of the laminated core described above are the same as those of the base steel sheet of the non-oriented electrical steel sheet. Furthermore, by combining this stator core and rotor core, a motor core can be made.

[0055] [Manufacturing Method] A method for manufacturing the non-oriented electrical steel sheet according to this embodiment, the laminated core according to this embodiment, and the rotating electrical machine according to this embodiment will be described.

[0056] <Method for manufacturing non-oriented electrical steel sheet> First, as a method for manufacturing a non-oriented electrical steel sheet according to this embodiment, a method for manufacturing a non-oriented electrical steel sheet as a rotor core material and a non-oriented electrical steel sheet as a stator core material will be described. A non-oriented electrical steel sheet having a predetermined {111}<211> orientation strength and {411}<011> orientation strength (the non-oriented electrical steel sheet as a rotor core material and the non-oriented electrical steel sheet as a stator core material have different preferred orientation strength ranges) can be obtained by controlling various conditions in the manufacturing process.

[0057] As a first example, we will explain an example of a manufacturing method for selectively producing non-oriented electrical steel sheets suitable for stator core materials and non-oriented electrical steel sheets suitable for rotor core materials by varying the manufacturing conditions after hot rolling using slabs of the same chemical composition. The non-oriented electrical steel sheet according to this embodiment is manufactured by hot rolling, cold rolling, and, if necessary, intermediate annealing, skin-pass rolling, finish annealing, and stress relief annealing to produce a base steel sheet, and then forming an insulating coating on the surface of the base steel sheet after any of the above processes. Non-oriented electrical steel sheets with predetermined {111}<211> orientation strength and {411}<011> orientation strength can be obtained by controlling various conditions in the manufacturing process, and the selective production of non-oriented electrical steel sheets suitable for stator core materials and non-oriented electrical steel sheets suitable for rotor core materials can be achieved by whether or not to perform intermediate annealing, skin-pass rolling, finish annealing, etc. Here, intermediate annealing refers to annealing performed between cold rolling and skin-pass rolling, and finish annealing refers to annealing performed after skin-pass rolling. This finish annealing may be performed by a steel sheet manufacturer or by a motor manufacturer (processing manufacturer) after punching out the iron core.

[0058] First, a steel material having the above-mentioned chemical composition is heated and hot-rolled. The steel material is, for example, a slab produced by ordinary continuous casting. The heating temperature of the steel material is not limited, but a standard condition of 1000 to 1350°C can be adopted. The rough rolling and finish rolling of the hot rolling are carried out by A r1 In other words, the temperature at the time of passing the final pass of the finish rolling (finishing temperature) is A r1 It is preferable to perform hot rolling so that the temperature is equal to or higher than the above temperature. As a result, subsequent cooling transforms austenite (γ iron) into ferrite (α iron), thereby refining the crystal structure. If cold rolling is then performed in a state in which the crystal structure has been refined, bulging recrystallization (a phenomenon in which recrystallized grains grow so as to bulge outward from non-recrystallized portions, hereinafter sometimes referred to as "bulging") is likely to occur, and it is possible to facilitate the growth of {411}<011> oriented crystal grains, which are normally difficult to grow. In the non-oriented electrical steel sheet according to this embodiment,r1 The temperature is A ｃ３ It is determined from the change in thermal expansion of the steel material (base steel plate) during cooling at an average cooling rate of 1°C / second after heating to a temperature. c1 The temperature (temperature at which the steel transforms into the γ phase) is determined from the change in thermal expansion of the steel material (steel sheet) during heating at an average heating rate of 1°C / second. However, if the chemical composition is non-transformation, the finishing temperature is preferably 850°C or higher. This is because if the finishing temperature is lower than 850°C, it becomes difficult to control the shape of the steel sheet during hot rolling.

[0059] Thereafter, the hot-rolled steel sheet is coiled without being annealed. If hot-rolled steel sheet annealing is performed, the {411}<011> orientation cannot be enriched in subsequent processes. The coiling temperature is not limited, but is preferably greater than 250°C and less than 700°C. By coiling the hot-rolled steel sheet after hot rolling at greater than 250°C and less than 700°C, the crystal structure before cold rolling can be refined, and the {411}<011> orientation, which has excellent magnetic properties, can be enriched during recrystallization. The coiling temperature is more preferably 400 to 600°C, and even more preferably 400 to 480°C.

[0060] Thereafter, the hot-rolled steel sheet is pickled and then cold-rolled. In cold rolling, the reduction ratio is preferably 80.0 to 92.0%. The higher the reduction ratio, the more likely it is that crystal grains of the {411}<011> orientation will grow due to subsequent recrystallization. On the other hand, if the reduction ratio exceeds 92.0%, the load during cold rolling will be high, resulting in increased costs. The reduction ratio in cold rolling is determined taking into account skin-pass rolling, which will be described later, so that the product plate thickness required after skin-pass rolling will be achieved.

[0061] After the cold rolling is completed, intermediate annealing is performed. However, intermediate annealing is not necessary. If intermediate annealing is performed, the temperature of the intermediate annealing is set to A c1 By controlling the temperature of the intermediate annealing to less than the temperature, the recrystallization rate is set to 1 to 99%, preferably 50 to 99%. If the temperature of the intermediate annealing is too low, there is a concern that bulging will not occur sufficiently and crystal grains of the {411}<011> orientation will not grow sufficiently. Therefore, the temperature of the intermediate annealing is preferably 600°C or higher. c1If the temperature is higher than this, austenite transformation occurs during annealing, and the frequency of occurrence of crystal grains having crystal orientations other than the {411}<011> orientation increases, which may impair the effect of the present invention. c1 When the chemical composition is non-transformation type, the intermediate annealing temperature is set to 800° C. or less. The time for such intermediate annealing is preferably 5 to 60 seconds.

[0062] It is preferable that the recrystallization rate is 50% or more after intermediate annealing, since this makes it easier for {411}<011> oriented grains to grow after finish annealing and stress relief annealing.

[0063] The recrystallization rate of a steel sheet (a cold-rolled steel sheet that serves as the base steel sheet for a non-oriented electrical steel sheet) after intermediate annealing can be determined by the following procedure. First, a sample taken from the steel sheet is polished from the surface so that the sheet thickness is reduced to half (so that the center of the sheet thickness is exposed), and the polished surface is observed using electron backscatter diffraction (EBSD). Grains that satisfy either one of the following conditions (a) or (b) are determined to be unrecrystallized portions, and the unrecrystallization rate is calculated as the area of ​​the unrecrystallized portion divided by the area of ​​the entire observation field. (a) Grains with a grain size of more than 300 μm. (b) Grains with an aspect ratio of more than 2, i.e., (length in the rolling direction) / (length in the direction 90 degrees from the rolling direction)>2.

[0064] After intermediate annealing is completed, skin-pass rolling is performed. Skin-pass rolling is not necessarily required. If intermediate annealing is not performed, skin-pass rolling is performed after cold rolling. Skin-pass rolling increases the strength in the {111}<211> orientation, resulting in a non-oriented electrical steel sheet suitable for use as a rotor core material.

[0065] The preferred range of the skin-pass rolling reduction can be determined assuming that the steel sheet that has undergone skin-pass rolling and then undergoes finish annealing is used as the stator core material, as described below. As described above, if a steel sheet that has experienced bulging undergoes light rolling and then further annealing, the {411}<011> oriented crystal grains that developed during bulging will grow further. This is an example of a phenomenon commonly known as strain-induced grain boundary migration (hereinafter sometimes referred to as SIBM). To utilize this phenomenon, the skin-pass rolling reduction is set to 5 to 25%. If the skin-pass rolling reduction is less than 5%, the amount of strain accumulated in the steel sheet is small, so SIBM does not occur. On the other hand, if the skin-pass rolling reduction is more than 25%, the strain is too great, resulting in recrystallization nucleation rather than SIBM. Nucleation increases the frequency of {111}<211> crystal grains, so if this steel sheet is used as a stator core material, the magnetic properties of the stator will deteriorate. From this perspective, in order to fully obtain the effect, it is more preferable to set the skin-pass rolling reduction to 5 to 15%. Furthermore, it is preferable to adjust the skin-pass rolling reduction ratios so that, where Rm is the cold rolling reduction ratio (%) and Rs is the skin-pass rolling reduction ratio (%), the following relationships are satisfied: 86<Rm+0.2×Rs<92 and 5<Rs<20.

[0066] The steel sheet after skin-pass rolling is subsequently subjected to finish annealing. Finish annealing is not necessary. If intermediate annealing or skin-pass rolling is not performed, finish annealing is performed on the steel sheet after cold rolling or after intermediate annealing. To obtain the effect of finish annealing, it is preferable to perform finish annealing on the steel sheet after skin-pass rolling. In this case, finish annealing can be performed at a temperature and time that releases the strain imparted by skin-pass rolling and causes recrystallization by SIBM. The higher the annealing temperature, the shorter the processing time that is possible. However, α → γ transformation should be avoided, and the upper limit of the temperature is A c1 It is preferable that the temperature is less than 600 to 600 A. c1 The temperature is less than 700°C, and the time is more than 0 seconds and less than 100 hours. c1Less than ℃, 1 to 300 seconds, if batch annealing furnace, 600 to A c1 Examples of suitable holding temperatures include less than 100°C and 20 to 1200 minutes. By appropriately controlling the holding temperature and time, the strain introduced by skin-pass rolling can be sufficiently released by SIBM, suppressing warpage when punching into complex shapes. At the same time, excessive coarsening of the crystal grains can be avoided, suppressing a decrease in punching accuracy due to sagging during punching. In other words, the workability of the non-oriented electrical steel sheet can be improved. If skin-pass rolling is not performed, the strain can be sufficiently released by finish annealing, so workability does not deteriorate in the first place. After finish annealing, the steel sheet has increased strength in the {411}<011> orientation, making it a non-oriented electrical steel sheet suitable for use as a stator core material. The temperature rise rate for finish annealing is preferably 30°C / sec or higher in order to increase strength in the {411}<011> orientation. More preferably, it is 100°C / sec or higher, or 200°C / sec or higher. The heating rate may also be 300° C. / sec or more, further 400° C. / sec or more, or 500° C. / sec or more. In particular, when the base steel sheet contains 0.010% or more of Ti, Nb, V, or Zr in total, if the heating rate in the finish annealing is less than 100° C. / sec, the effect of reducing the {411}<011> orientation strength is significant, and therefore the heating rate is preferably 100° C. / sec or more.

[0067] In general stress relief annealing, even if stress relief annealing is performed only on the stator, the {411}<011> orientation strength does not increase significantly, but the {111}<011> orientation strength increases. Therefore, it is difficult to satisfy the relationship B / A > 1.0 between the {111}<211> orientation strength (A) of the intended stator core material and the {111}<211> orientation strength (B) of the rotor core material, and the relationship C / D > 1.0 between the {411}<011> orientation strength (C) of the stator core material and the {411}<011> orientation strength (D) of the rotor core material. On the other hand, in the above-mentioned method utilizing bulging and SIBM, by annealing only the stator, the {411}<011> orientation grows by encroaching on the {111}<211> orientation, which is very advantageous for satisfying the desired relationships of B / A > 1.0 and C / D > 1.0.

[0068] When the non-oriented electrical steel sheet according to this embodiment is used for a motor core, it is subjected to forming processing (e.g., punching) to form it into a desired core member shape. Then, stress relief annealing may be performed to remove strains caused by the forming processing. The above-mentioned finish annealing may be performed as stress relief annealing for a stator core. It is preferable that the stress relief annealing temperature is, for example, about 800°C, and the stress relief annealing time is about 2 hours.

[0069] In the non-oriented electrical steel sheet according to this embodiment, an insulating coating is formed on the surface of the base steel sheet after the last of the steps of cold rolling, intermediate annealing, skin-pass rolling, and finish annealing, and before or after stress relief annealing. The conditions for forming the insulating coating may be the same as those for forming an insulating coating on a conventional non-oriented electrical steel sheet.

[0070] Another example of separate production of non-oriented electrical steel sheets for rotor cores and hot-rolled non-oriented electrical steel sheets for stator cores is a method in which slabs with the same chemical composition are hot-rolled, cold-rolled, intermediate-annealed, and skin-pass rolled under the same conditions (as the same sheet), and then the two are separated by whether or not finish annealing and stress relief annealing are performed. In this method, a steel sheet manufacturer produces and ships steel sheets that have undergone the skin-pass process. A motor manufacturer (processing manufacturer) then punches (commonly referred to as one-piece punching) the rotor core material and the stator core material from the same steel sheet. The rotor core is used without stress relief annealing, while the stator core is used after stress relief annealing, thereby manufacturing the rotating electric machine of the present invention. Because the rotor core material and the stator core material are separately produced during stress relief annealing, the final step in motor core production, this method is advantageous in terms of logistics, steel sheet handling, and steel sheet yield, making it an industrially desirable method. That is, for example, the non-oriented electrical steel sheet contained in the stator may be a steel sheet obtained by further subjecting the non-oriented electrical steel sheet contained in the rotor to heat treatment (finish annealing or stress relief annealing) at 600° C. or higher. In this way, an iron core material applicable to the rotating electrical machine according to this embodiment can be obtained.

[0071] The non-oriented electrical steel sheet that is the material for the rotor core of the rotating electric machine according to this embodiment and the hot-rolled non-oriented electrical steel sheet that is the material for the stator core may be separately produced by methods other than those described above. For example, they may be produced using steel materials with different chemical compositions, and they may be separately produced by changing the hot-rolling conditions, cold-rolling conditions, etc.

[0072] As for the conditions not explained above, known conditions can be appropriately adopted.

[0073] The electromagnetic steel sheet (non-oriented electromagnetic steel sheet) manufactured in this manner is suitable as a stator core material or rotor core material for the rotating electric machine according to this embodiment. Basically, a steel sheet manufactured so that the accumulation in the {111}<211> orientation is suppressed and the accumulation in the {411}<011> orientation is promoted is a suitable electromagnetic steel sheet for a stator core material, and a steel sheet manufactured so that the accumulation in the {111}<211> orientation is promoted is a suitable electromagnetic steel sheet for a rotor core material. Furthermore, when stress relief annealing is performed on the motor core, a steel sheet that takes into account the change in crystal orientation due to stress relief annealing can be applied. The rotating electric machine according to this embodiment can be obtained by selecting and using steel sheets so that the orientation strengths (A), (B), (C), (D), (E), and (F) of each core material satisfy a predetermined relationship. The method of using two types of steel sheets with different textures created by the chemical composition, hot rolling conditions, hot-rolled sheet heat treatment conditions, cold rolling conditions, finish annealing conditions, etc. as the stator core material and rotor core material, respectively, does not involve so-called one-piece punching, and therefore it must be noted that this method may be disadvantageous in terms of steel sheet yield compared to the aforementioned method of punching the stator core material and rotor core material from one type of steel sheet. However, because it is possible to completely independently control the texture of each steel sheet, if the steel sheets are selected appropriately, it can also be advantageous in terms of the magnitude of the effect.

[0074] <Method for Manufacturing Laminated Core> The laminated core according to this embodiment is manufactured by using, as the material for the stator core, a non-oriented electrical steel sheet having a {111}<211> orientation strength of less than 15 and a {411}<011> orientation strength of 2 to 50, among the non-oriented electrical steel sheets according to this embodiment described above. Alternatively, the laminated core is manufactured by using, as the material for the rotor core, a non-oriented electrical steel sheet having a {111}<211> orientation strength of 2 to 30 and a {411}<011> orientation strength of 1 to 40. Specifically, separate non-oriented electrical steel sheets are prepared for the stator and the rotor, and each is punched and laminated. Alternatively, the same electrical steel sheets may be punched and laminated for the stator and rotor, with stress relief annealing being performed only on the stator. Known methods may be used for punching and laminating.

[0075] <Method for manufacturing a rotating electric machine> The rotating electric machine according to this embodiment is manufactured by assembling the laminated core by a known method after manufacturing the laminated core described above, by winding the laminated core, and then inserting the laminated core into a housing. In this case, the order of winding and inserting the laminated core into the housing may be reversed.

[0076] Hereinafter, the embodiments of the present invention will be further described using examples. The conditions used in the examples are merely examples for confirmation, and the present invention is not limited to these examples. Various conditions may be adopted as long as they do not deviate from the present invention and the object of the present invention is achieved.

[0077] (Manufacturing of Electrical Steel Sheets) Molten steel was cast to produce ingots, which were then subjected to hot rolling, pickling, and cold rolling, and in some cases, one or more steps of intermediate annealing, skin pass rolling, and finish annealing to produce electrical steel sheets (non-oriented electrical steel sheets). The chemical composition and transformation temperature of each steel type of the obtained electrical steel sheets are shown in Table 1. In the chemical composition, the content of impurities not specified in the table was 0.0010% or less, and 0.10% or less in total. A r1 (°C) is the temperature at which the alloy transforms into the α phase, c1 (°C) indicates the temperature at which the alloy transforms into the γ phase. For chemical compositions that do not undergo α-γ transformation (non-transformation system), "-" is entered in the column for the phase transformation temperature. １）The column shows the calculation results of Nb / 93 + Zr / 91 + Ti / 48 + V / 51 - (C / 12 + N / 14) using the mass % contents of Nb, Zr, Ti, V, C, and N. Various manufacturing conditions are shown in Tables 2-1 and 2-2. In addition, when a known Al was applied to the surface of the electrical steel sheet obtained by the above method, ２ O ３ The thickness of the insulating coating was 0.5 μm. The final thickness in Table 2 is the thickness of the base steel sheet after the steps in Table 2 were completed.

[0078]

[0079]

[0080]

[0081] (Motor manufacturing and evaluation) Next, the obtained electromagnetic steel sheets were used to manufacture the stator core and rotor core used in the above-mentioned evaluation motor. At that time, as shown in Tables 3-1 to 3-4, some of the cores were subjected to stress relief annealing at 800°C for 2 hours. These cores were then combined to manufacture an evaluation motor, and motor loss and noise were measured.

[0082] (Evaluation Motor) FIG. 1 is a partial plan view of the motor. The motor 300 is an IPM motor manufactured based on the Institute of Electrical Engineers of Japan (IEICE) Model D. The outer diameter of the stator core 3 is 112 mm (= 54 mm + 0.5 mm × 2 + 28.5 mm × 2), the outer diameter of the rotor 302 is 54 mm, and the stack height of the stator core 3 is 100 mm. There are 24 slots. The stator core 3 is fixed to the housing 301 by shrink fitting. The inner diameter of the stator core 3 is 55 mmφ, and the gap between the rotor 302 and the stator core 3 is 0.5 mm. The stator core has 24 slots, the number of turns per phase of the copper wire wound around the teeth of the stator core is 35, and the magnetic flux density Br of the rotor magnet is 1.25 T.

[0083] (Motor Loss) (Noise) In this example, the loss (motor loss (W)) and noise generated in the motor when the motor was driven for 60 minutes at a rotation speed of 1500 RPM with a winding current of peak value 3 A flowing at a phase angle of 30 degrees were determined. The motor loss was calculated by calculating the power (W) required under the above operating conditions and the motor's workload (W), and then subtracting the workload from the power. The power was measured using a wattmeter. The workload was calculated by attaching a torque meter to the end of the motor and multiplying the torque by the rotation speed. The noise measurement was carried out in an anechoic chamber with a background noise of 16 dBA, with the sound level meter positioned 0.3 m from the surface of the iron core, and A-weighting was used for hearing correction. For noise, Test No. The noise generated during operation of motors No. 1, 16, 21, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, and 61 was used as the standard, and the difference compared to a standard using the same steel type was evaluated. The orientation strength of the core material for each core, along with the motor loss and noise (relative values), are shown in Tables 3-1 to 3-8. If stress relief annealing was performed after the core was made, the orientation strength shown here is the measurement value for the core material after stress relief annealing.

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092] The effects of the present invention are evaluated in terms of relative values ​​to the motor loss and noise of a motor in which the stator core material and rotor core material are made of the same steel plate. An example of the invention is when a motor in which the stator core material and rotor core material are made of different steel plates has smaller motor loss and noise than a motor made of the same steel plate (steel plate of the same steel type and manufacturing conditions).

[0093] Test Nos. 1, 16, 21, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, and 61 in Tables 3-1 to 3-8 are examples in which the stator and rotor core materials were made of the same steel type and steel sheets were subjected to the same stress relief annealing conditions. These are referred to as Comparative Example (Standard A), Comparative Example (Standard B), Comparative Example (Standard D), Comparative Example (Standard F), Comparative Example (Standard G), Comparative Example (Standard H), Comparative Example (Standard I), Comparative Example (Standard J), Comparative Example (Standard K), Comparative Example (Standard L), Comparative Example (Standard M), Comparative Example (Standard N), Comparative Example (Standard O), Comparative Example (Standard P), Comparative Example (Standard Q), Comparative Example (Standard R), Comparative Example (Standard S), Comparative Example (Standard T), and Comparative Example (Standard U), respectively. Test Nos. 1 to 15 are examples in which steel type A listed in Table 1 was used. Nos. 1 to 15 are invention examples. It can be seen that Tests Nos. 2 to 7, 10, 11, and 15 had lower motor losses and noise than the comparative example (reference A), which served as the standard. Tests Nos. 16 to 18 are examples using component B listed in Table 1. Inventive Example No. 17 was an example in which the cold rolling reduction ratio was changed, and Inventive Example No. 18 was an example in which the {111}<211> orientation strength of the stator core material was weakened and the {411}<011> orientation strength was increased by changing the heating rate. Test No. 19 was an example in which a steel plate containing Nb was used as the rotor core material to increase the {111}<211> orientation strength. It can be seen that Inventive Examples 17 to 19 had lower motor losses and noise than the comparative example (reference B), which served as the standard. Tests Nos. 21 to 25 are examples in which component D listed in Table 1 was used. Inventive Example No. It can be seen that Test No. 22 to 25 have lower motor loss and noise than Test No. 21 (Comparative Example (Standard D)), which was used as the standard.

[0094] Test No. 26 is a combination of the stator (D1) and rotor (E1) steel sheets. The rotor core material was a steel sheet containing Ti to enhance the {111}<211> orientation strength, resulting in lower motor loss and noise than Test No. 21 (Comparative Example (Standard D)). Invention Examples Nos. 28, 29, and 30 are combinations of the stator (A1) and rotor (D1), rotor (V1), or rotor (W1). In these examples, a transformation-type material (low-Si steel) was used for the rotor core material, enhancing the {111}<211> orientation strength, resulting in lower motor loss and noise than Test No. 21 (Comparative Example (Standard D)).

[0095] Test Nos. 31 and 32 are examples using steel type F listed in Table 1. It can be seen that Test No. 32, an example of the invention, had lower motor loss and noise than Test No. 31 (comparative example (reference F)), which was used as the standard. Test Nos. 33 and 34 are examples using steel type G listed in Table 1. It can be seen that Test No. 34, an example of the invention, had lower motor loss and noise than Test No. 33 (comparative example (reference G)), which was used as the standard.

[0096] Similarly, Test Nos. 36 to 62 are examples in which steel types H to U listed in Table 1 were used. It can be seen that Test Nos. 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, and 62 each had lower motor loss and noise than Test Nos. 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, and 61, which were benchmarks using similar steel types.

[0097] On the other hand, in Test Nos. 8, 9, 12, 14, 20, and 27, the predetermined directional strength was not obtained, and the motor loss and noise were inferior to the standards.

[0098] The rotating electric machine according to the present invention has excellent characteristics in terms of motor loss and noise by using different steel sheets for the stator core material and the rotor core material, each of which has its chemical composition, hot rolling conditions, cold rolling conditions, and annealing conditions appropriately controlled.

[0099] The present invention can provide a rotating electric machine that is excellent in motor loss and noise, and is therefore extremely useful in industry.

[0100] 3 stator core 300 motor 301 housing 302 rotor

Claims

1. A rotating electrical machine comprising a stator, a rotor, and a housing that houses the stator and the rotor, wherein A, which is the {111}<211> orientation strength of the base steel sheet of the non-oriented electrical steel sheet included in the stator, is less than 15; B, which is the {111}<211> orientation strength of the base steel sheet of the non-oriented electrical steel sheet included in the rotor, is 2 to 30, and A and B satisfy the relationship B / A > 1.0; C, which is the {411}<011> orientation strength of the base steel sheet of the non-oriented electrical steel sheet included in the stator, is 2 to 50; D, which is the {411}<011> orientation strength of the base steel sheet of the non-oriented electrical steel sheet included in the rotor, is 1 to 40, and C and D satisfy the relationship C / D > 1.0; and the base steel sheets of the non-oriented electrical steel sheets included in the rotor and the stator each have a chemical composition containing, in mass%, C: 0.0100% or less, Si: 0.5000 to 4.0000%, sol.Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: a total of 0.1000 to 5.0000%, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 to 0.4000%, Ti: 0 to 0.1000%, Nb: 0 to 0.1000%, Zr: 0 to 0.1000%, V: 0 to 0.1000%, with the balance being Fe and impurities.

2. The rotating electrical machine according to claim 1, wherein in the non-oriented electrical steel sheet included in the rotor, B and E, which is the {111}<011> orientation strength, satisfy the relationship B / E > 1.

0.

3. The rotating electrical machine according to claim 1, wherein in the non-oriented electrical steel sheet included in the stator, C and F, which is the {100}<011> orientation strength, satisfy the relationship C / F > 1.

0.

4. The difference in the total of the Si content, Mn content, and sol. Al content in the base steel sheet between the non-oriented electromagnetic steel sheet included in the stator and the non-oriented electromagnetic steel sheet included in the rotor is within 0.20% by mass, and the average crystal grain size of the non-oriented electromagnetic steel sheet included in the stator is larger than the average crystal grain size of the non-oriented electromagnetic steel sheet included in the rotor. The rotating electrical machine according to any one of claims 1 to 3, characterized in that.

5. The Si content, Ti content, and Nb content of the base steel sheet of the non-oriented electromagnetic steel sheet included in the stator are represented by Si ｓ , Ti ｓ , Nb ｓ in % by mass, respectively, and the Si content, Ti content, and Nb content of the base steel sheet of the non-oriented electromagnetic steel sheet included in the rotor are represented by Si ｒ , Ti ｒ , Nb ｒ in % by mass, respectively. When Si ｓ / Si ｒ > 1.0, Ti ｒ / Ti ｓ > 1.0, Nb ｒ / Nb ｓ > 1.0 is satisfied. The rotating electrical machine according to any one of claims 1 to 3, characterized in that.

6. The Nb content, Zr content, Ti content, V content, C content, and N content of the base steel sheet of the non-oriented electromagnetic steel sheet included in the stator are represented by Nb ｓ , Zr ｓ , Ti ｓ , V ｓ , C ｓ , N ｓ in % by mass, respectively. When 0 ≧ Nb ｓ / 93 + Zr ｓ / 91 + Ti ｓ / 48 + V ｓ / 51 - (C ｓ / 12 + N ｓ / 14) is satisfied. The rotating electrical machine according to any one of claims 1 to 3, characterized in that.

7. The Nb content, Zr content, Ti content, V content, C content, and N content of the base steel sheet of the non-oriented electromagnetic steel sheet included in the rotor are represented by Nbｒ , Zr ｒ , Ti ｒ , V ｒ , C ｒ , N ｒ When it is as follows, 0 < Nb ｒ / 93 + Zr ｒ / 91 + Ti ｒ / 48 + V ｒ / 51 - (C ｒ / 12 + N ｒ / 14) < 5.0×10 －３ The rotating electric machine according to any one of claims 1 to 3, characterized in that it satisfies this.

8. It includes a base steel plate and an insulating film formed on the surface of the base steel plate. The base steel plate contains, by mass%, C: 0.0100% or less, Si: 0.5000 to 4.0000%, sol.Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: a total of 0.1000 to 5.0000%, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 to 0.4000%, Ti: 0 to 0.1000%, Nb: 0 to 0.1000%, Zr: 0 to 0.1000%, V: 0 to 0.1000%, and the balance consists of Fe and impurities. In the base steel plate, the {111}<211> orientation intensity is less than 15, and the {411}<011> orientation intensity is 2 to 50. Non-oriented electromagnetic steel sheet.

9. An isotropic electromagnetic steel sheet comprising a base steel sheet and an insulating film formed on the surface of the base steel sheet, wherein the base steel sheet has, by mass%, C: 0.0100% or less, Si: 0.5000 to 4.0000%, sol.Al: 0.0001 to 1.0000%, S: 0.0100% or less, N: 0.0100% or less, one or more selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: a total of 0.1000 to 5.0000%, Cr: 0 to 2.0000%, Sn: 0 to 0.4000%, Sb: 0 to 0.4000%, P: 0 to 0.4000%, Ti: 0 to 0.1000%, Nb: 0 to 0.1000%, Zr: 0 to 0.1000%, V: 0 to 0.1000%, and the balance consists of Fe and impurities, and in the base steel sheet, the {111}<211> orientation intensity is 2 to 30, and the {411}<011> orientation intensity is 1 to 40.

10. A laminated core formed by laminating the isotropic electromagnetic steel sheet according to claim 8.

11. A laminated core formed by laminating the isotropic electromagnetic steel sheet according to claim 9.

12. The rotating electrical machine according to any one of claims 1 to 3, wherein the isotropic electromagnetic steel sheet included in the stator is a steel sheet obtained by further performing heat treatment at 600 °C or higher on the isotropic electromagnetic steel sheet included in the rotor.

13. A method for manufacturing a laminated core, comprising a step of processing and laminating the isotropic electromagnetic steel sheet according to claim 8.

14. A method for manufacturing a laminated core, comprising a step of processing and laminating the isotropic electromagnetic steel sheet according to claim 9.

15. A method for manufacturing a rotating electrical machine, comprising a step of assembling the laminated core according to claim 10 and the laminated core according to claim 11.

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