JP2017166023A - Electromagnetic steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic steel sheet with excellent magnetic properties, mechanical properties, and dimensional accuracy during a punching process.SOLUTION: There is provided an electromagnetic steel sheet containing, by mass%, C: 0.005% or less, Si: 3.0% to 4.0%, Mn: 3.0% or less, S: 0.004% or less, sol.Al: 0.1% to 1.5%, P: 0.03% to 0.15% and the balance Fe with impurities with 3.5%≤Si+sol.Al+0.5×Mn≤5.0% and having yield strength of 400 MPa or more and peak half-width of a (211) surface in an X ray diffraction profile measured on a steel sheet surface of 0.16° or less.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrical steel sheet effective for improving the performance of a rotating machine such as a motor and a generator.

  In recent years, global warming issues, environmental pollution issues, and energy issues have gained increasing interest. In order to solve these problems, it is an important issue to improve the efficiency of motors and generators used in many electrical devices. Specifically, there is a demand for improvement in the magnetic properties of electrical steel sheets that are the core material of motors and generators.

  In addition, with the progress of power electronics, those that utilize the drive frequency of motors and generators to a high frequency range exceeding the conventional commercial frequency range are increasing. For this reason, in the electrical steel sheet used for the iron core material, there is an increasing demand for products with low iron loss not only in the low frequency range but also in the high frequency range. In particular, a compressor motor of an air conditioner and a refrigerator, or a drive motor or a generator of a hybrid vehicle (Hybrid Electric Vehicle: HEV) and an electric vehicle (Electric: Vehicle: EV) has a low iron loss in a high frequency range and a high magnetic flux density. An electrical steel sheet is desired. Furthermore, the demand for the material strength of the electrical steel sheet that can withstand high-speed rotation during high-frequency driving has also increased.

  In order to reduce iron loss (particularly, high-frequency iron loss), for example, it is effective to make a magnetic alloy high alloy and reduce eddy current loss by increasing the specific resistance. Moreover, the solid solution strengthening by high alloying also contributes to the strength increase of the electrical steel sheet. However, since the increase in the amount of alloy of the electromagnetic steel sheet decreases the magnetic flux density, it is difficult to achieve both a low iron loss and high strength and a high magnetic flux density.

  In order to solve the above problems, for example, in Patent Document 1 below, Si: 2.5% to 4.5% and Mn: 0.005% to 1.0% in mass%. An electrical steel sheet having an Al content of 200 ppm or less, S, N and O contents of 30 ppm or less, and the balance being substantially Fe, and an average crystal grain size of 0.05 mm The area ratio of crystal grains having an orientation difference from the {110} <001> orientation within 20 ° is 25% to 75%, and the tensile strength is 400 MPa or more. An electromagnetic steel sheet for motor cores excellent in high-frequency magnetic characteristics and mechanical strength characteristics has been proposed.

  In addition, in Patent Document 1, in addition to the above characteristics, P: 0.005% to 0.20%, Ni: 0.01% to 3.50%, Sn: 0.01% to 0 in mass%. 20%, at least one selected from Sb: 0.005% to 0.50%, Cu: 0.01% to 0.50%, and Cr: 0.01% to 1.50%. An electrical steel sheet further containing elements has also been proposed.

In Patent Document 2 below, Si: 0.8% to 2.5%, Mn: 0.1% to 2.5%, sol. Al: 1.5% or less, P: 0.005% to 0.30%, or Ni: 0.05% to 1.5%, further containing at least one, with the balance being Fe And the product of the mass fraction of Fe and the density of the steel is 7.35 or more, the magnetic flux density is 1.50 T or more at B ₅₀ , the yield strength is 300 MPa or more, and the thickness is 0.15 mm. A non-oriented electrical steel sheet characterized by being 0.40 mm or less has been proposed.

JP 2002-146491 A JP 2002-371340 A

  However, the electromagnetic steel sheet disclosed in Patent Document 1 has a large variation in magnetic properties because of its low Al content. Further, when the strength of the electrical steel sheet was increased, the dimensional accuracy during the punching process was not at a satisfactory level.

  Moreover, in the electrical steel sheet disclosed in Patent Document 2, since the Si content is small, the high-frequency iron loss and the mechanical properties cannot be satisfied at a satisfactory level. Further, when the strength of the electrical steel sheet was increased, the dimensional accuracy during the punching process was not at a satisfactory level.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide an electromagnetic wave with low iron loss, high magnetic flux density and high strength, and excellent dimensional accuracy during punching. It is to provide a steel sheet.

  The inventors of the present invention have added an effect of reducing iron loss by increasing electric resistance and adding Si having a high solid solution strengthening ability in an amount of 3.0% by mass or more and 4.0% by mass or less. P is added in an amount of 0.03% by mass or more and 0.15% by mass or less, and an appropriate amount of Al and Mn is further added, so that 3.5% by mass ≦ Si + Al + 0.5 × Mn ≦ 5.0% by mass. By using a high alloy material, it was understood that improvement in high-frequency iron loss and increase in strength could be achieved while suppressing reduction in magnetic flux density.

  However, since it was found that the magnetic steel sheet having a yield strength of 400 MPa or more has poor dimensional accuracy at the time of punching, further investigation was made including the correspondence to the dimensional accuracy at the time of punching. As a result, in the X-ray diffraction profile measured on the surface of the steel sheet, by controlling the peak half-value width of the (211) plane to 0.16 ° or less, it is possible to obtain a plan for improving the dimensional accuracy during the punching process. I found it. By referring to these findings, the present inventors have found that an electrical steel sheet excellent in magnetic properties, mechanical properties and dimensional accuracy can be obtained.

  The summary of this invention completed based on the said knowledge is as follows.

  (1) By mass%, C: 0.005% or less, Si: 3.0% or more and 4.0% or less, Mn: 3.0% or less, S: 0.004% or less, sol. Al: 0.1% or more and 1.5% or less, P: 0.03% or more and 0.15% or less, with the balance being Fe and impurities, 3.5% ≦ Si + Al + 0.5 × Mn ≦ 5. An electrical steel sheet having 0%, yield strength of 400 MPa or more, and a peak half-value width of (211) plane in an X-ray diffraction profile measured on the steel sheet surface of 0.16 ° or less.

  (2) By mass%, C: 0.005% or less, Si: 3.0% or more and 4.0% or less, Mn: 3.0% or less, S: 0.004% or less, sol. 2. Al: 0.1% or more and 1.5% or less, P: 0.03% or more and 0.15% or less, Sn: 0.001 to 0.15%, with the balance being Fe and impurities. 5% ≦ Si + Al + 0.5 × Mn ≦ 5.0%, the yield strength is 400 MPa or more, and the peak half-value width of the (211) plane of the X-ray diffraction profile measured on the steel sheet surface is 0.16 ° or less. A magnetic steel sheet.

  As described above, according to the present invention, it is possible to provide an electrical steel sheet that has high magnetic flux density, low high-frequency iron loss, high strength, and good dimensional accuracy during punching.

It is a schematic diagram explaining the peak half-value width in an X-ray diffraction profile. It is a graph which shows the influence of the yield strength with respect to the dimensional accuracy at the time of a punching process, and the peak half value width of (211) plane.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  The inventors have succeeded in obtaining an electrical steel sheet having excellent magnetic properties, mechanical properties, and workability by radically reviewing the chemical composition and the shape of the X-ray diffraction profile measured on the steel plate surface. .

  The electrical steel sheet according to one embodiment of the present invention is as follows. Specifically, the electrical steel sheet according to the present embodiment is a non-oriented electrical steel sheet having the following characteristics.

  (1) By mass%, C: 0.005% or less, Si: 3.0% or more and 4.0% or less, Mn: 3.0% or less, S: 0.004% or less, sol. Al: 0.1% or more and 1.5% or less, P: 0.03% or more and 0.15% or less, with the balance being Fe and impurities, 3.5% ≦ Si + Al + 0.5 × Mn ≦ 5. An electrical steel sheet having 0%, yield strength of 400 MPa or more, and a peak half-value width of (211) plane in an X-ray diffraction profile measured on the steel sheet surface of 0.16 ° or less.

  (2) By mass%, C: 0.005% or less, Si: 3.0% or more and 4.0% or less, Mn: 3.0% or less, S: 0.004% or less, sol. Al: 0.1% to 1.5%, P: 0.03% to 0.15%, Sn: 0.001% to 0.15%, with the balance being Fe and impurities, 3.5% ≦ Si + Al + 0.5 × Mn ≦ 5.0%, the yield strength is 400 MPa or more, and the peak half-value width of the (211) plane in the X-ray diffraction profile measured on the steel sheet surface is 0.16 °. The electrical steel sheet which is the following.

<1. About the chemical composition of steel>
Below, the chemical composition of the steel of the electromagnetic steel plate which concerns on this embodiment is demonstrated in detail first. Hereinafter, unless otherwise specified, the notation “%” represents “mass%”. Moreover, in the chemical composition of the steel of the electrical steel sheet according to the present embodiment, the balance other than the elements described below consists of Fe and impurities.

[C: 0.005% or less]
C (carbon) is an element that causes iron loss deterioration. Therefore, in the electrical steel sheet according to the present embodiment, the upper limit of the C content is set to 0.005%. When the C content exceeds 0.005%, iron loss deterioration occurs in the magnetic steel sheet, and good magnetic properties cannot be obtained. The C content is desirably 0.004% or less, and more desirably 0.003% or less. Note that the lower the C content, the better. The lower limit of the C content is not particularly limited, but is, for example, 0.0001%.

[Si: 3.0% to 4.0%]
Si (silicon) is an element that increases the electrical resistance of steel, reduces eddy current loss, and improves high-frequency iron loss. Moreover, since Si has a large solid solution strengthening ability, it is an element effective for increasing the strength of electrical steel sheets. In order to fully exhibit these effects, it is necessary to contain 3.0% or more of Si. However, when the Si content exceeds 4.0%, the workability of the electrical steel sheet is remarkably deteriorated, so that, for example, cold rolling of the electrical steel sheet becomes difficult. Therefore, the upper limit of the Si content is 4.0%. The Si content is desirably 3.1% or more and 3.9% or less, and more desirably 3.2% or more and 3.8% or less.

[Mn: 3.0% or less]
Mn (manganese) is an effective element for increasing the electrical resistance of steel, reducing eddy current loss, and improving high-frequency iron loss. However, when the Mn content exceeds 3.0%, the magnetic flux density is significantly reduced. Therefore, the upper limit of the Mn content is 3.0%. The Mn content is desirably 2.6% or less, and more desirably 2.2% or less. Even when the content of Mn is small, if the electric resistance is increased by increasing the content of Si and Al, the high-frequency iron loss of the electrical steel sheet can be reduced, so the lower limit value of the Mn content is particularly limited. For example, it is 0.01%.

[Sol. Al (acid-soluble Al): 0.1% to 1.5%]
Al (aluminum) is an effective element for reducing eddy current loss and improving high-frequency iron loss by increasing the electrical resistance of the electrical steel sheet. sol. When the content of Al (also simply referred to as Al) is less than 0.1%, the effect of increasing electrical resistance is small, and since AlN precipitates finely in the electrical steel sheet, the crystal grains become fine. Adversely affects iron loss reduction. Therefore, the lower limit of the Al content is 0.1%. On the other hand, when the Al content exceeds 1.5%, the magnetic flux density of the electrical steel sheet is significantly reduced. Therefore, the Al content is set to 0.1% to 1.5%. The Al content is desirably 0.2% to 1.4%, and more desirably 0.3% to 1.3%.

[P: 0.03% to 0.15%]
P (phosphorus) has a large solid solution strengthening ability and, in addition, has an effect of increasing the {100} texture, which is advantageous for improving magnetic properties, and is extremely effective in achieving both high strength and high magnetic flux density. It is an element. Further, since the increase in {100} texture contributes to reducing the anisotropy of mechanical properties in the plane of the steel plate, P is an effect of improving the dimensional accuracy at the time of punching the electromagnetic steel plate. Also have. In order to obtain the effect of improving such strength, magnetic characteristics, and dimensional accuracy, it is necessary to contain 0.03% or more of P in the electromagnetic steel sheet. However, when the P content exceeds 0.15%, the ductility of the electrical steel sheet is remarkably lowered, so the upper limit of the P content is 0.15%. The P content is desirably 0.04% or more and 0.14% or less, and more desirably 0.05% or more and 0.13% or less.

[S: 0.004% or less]
S (sulfur) is an element that degrades the magnetic properties of the electrical steel sheet by forming MnS. Therefore, the content of S is set to 0.004% or less. The S content is desirably 0.003% or less, and more desirably 0.002% or less. The smaller the S content, the better. The lower limit of the S content is not particularly limited, and is, for example, 0.0001%.

[Sn: 0.001% to 0.15%]
Sn (tin) is an element that improves magnetic properties by suppressing nitridation and oxidation of the surface layer portion of the electrical steel sheet during finish annealing. Therefore, the steel constituting the electromagnetic steel sheet according to this embodiment may further contain Sn. In addition, in order to acquire said effect, content of Sn needs to be 0.001% or more. On the other hand, when the Sn content exceeds 0.15%, the above effect is saturated. Therefore, when Sn is contained in the electrical steel sheet according to the present embodiment, the content of Sn is set to be 0.001% or more and 0.15% or less. The Sn content is desirably 0.005% or more and 0.14% or less, and more desirably 0.01% or more and 0.13% or less.

[Si + Al + 0.5 × Mn: 3.5% to 5.0%]
In order to reduce iron loss (particularly high-frequency iron loss), it is effective to increase the electrical resistance by adding alloy elements (Si, Al and Mn). Therefore, in the electrical steel sheet according to the present embodiment, it is important that the sum of the contents of alloy elements (Si, Al, and Mn) is within the above range. Note that the amount of increase in electrical resistance per Mn content (unit%) was about half that of Si and Al, so Si + Al + 0.5 × Mn was used as an index of alloy addition. When Si + Al + 0.5 × Mn is less than 3.5%, sufficient electrical resistance cannot be obtained, so that it is difficult for the electromagnetic steel sheet to achieve satisfactory high-frequency iron loss. On the other hand, when Si + Al + 0.5 × Mn exceeds 5.0%, there are too many alloy elements, so the magnetic flux density of the electrical steel sheet is significantly reduced. Therefore, Si + Al + 0.5 × Mn is 3.5% or more and 5.0% or less. Si + Al + 0.5 × Mn is desirably 3.6% or more and 4.9% or less, and more desirably 3.7% or more and 4.8% or less.

  In the electrical steel sheet according to the present embodiment, the content of elements such as Ni (nickel), Cr (chromium), Cu (copper), and Mo (molybdenum) other than the elements described above is not particularly specified. The electrical steel sheet according to the present embodiment has no particular problem even if these elements are contained at 0.3% or less. Moreover, in order to promote the crystal grain growth during the finish annealing of the electrical steel sheet, the electrical steel sheet according to the present embodiment may contain Ca (calcium) in a range of 30 ppm or less, and rare earth elements (Rare Earth Metal: REM) may be contained in the range of 100 ppm or less. Furthermore, the electrical steel sheet according to the present embodiment may contain any element as an impurity as long as the effects of the present invention are not hindered.

<2. About Yield Strength>
[Yield strength: 400 MPa or more]
Next, the yield strength of the electrical steel sheet according to this embodiment will be described.

  In recent years, the number of rotations of a motor has been increasing more and more due to miniaturization and higher output of the motor. Since a large centrifugal force and repeated stress are applied to the rotor core that rotates at high speed, the possibility of deformation and fatigue failure of the rotor core has increased.

  In order to suppress such deformation and fatigue failure of the rotor core, the yield strength of the electrical steel sheet according to this embodiment is set to 400 MPa or more. The yield strength of the electrical steel sheet according to the present embodiment is desirably 410 MPa or more, and more desirably 420 MPa or more. From the viewpoint of further suppressing deformation and fatigue failure of the rotor core, the upper limit of the yield strength of the electromagnetic steel sheet is not particularly defined. However, when the yield strength of the electrical steel sheet exceeds 800 MPa, the manufacturing cost increases, which is not desirable.

  In order to increase the yield strength of the electrical steel sheet and make it within the scope of the present invention, for example, increase the content of elements having high solid solution strengthening ability such as Si or P, and refine the crystal grain size of the electrical steel sheet What is necessary is just to use. However, when the crystal grain size is excessively refined, the iron loss is deteriorated. Therefore, the crystal grain size needs to be controlled to an appropriate grain size in which both strength and iron loss are compatible.

  The yield strength can be measured, for example, by using a method described in JIS Z 2241. For example, the upper yield point of a magnetic steel sheet or the 0.2% yield strength that is the yield strength when causing a permanent elongation of 0.2% may be obtained and used.

<3. Peak half-width in X-ray diffraction profile>
[(211) plane peak half width: 0.16 ° or less]
Then, with reference to FIG. 1, the shape of the X-ray-diffraction profile of the electromagnetic steel plate which concerns on this embodiment is demonstrated. FIG. 1 is a schematic diagram for explaining the peak half-value width in an X-ray diffraction profile.

  The half width is, for example, a peak width at an intensity (Ip / 2) that is half the peak intensity Ip in the peak of the X-ray diffraction profile as shown in FIG. It is known that the peak half width in the X-ray diffraction profile increases in correlation with the occurrence of plastic strain. Although the above correlation is observed in various diffraction planes, the present inventors have intensively studied at the peak of the (211) plane, and it is important that the upper limit value of the peak half width is as described above. I found out.

  Specifically, by mass%, C: 0.002%, Si: 3.12%, Mn: 0.26%, P: 0.082%, S: 0.001%, sol. Al: 0.65%, Sn: 0.03% Containing 0.30mm thick electrical steel sheet with the balance being Fe and impurities, and by mass, C: 0.002%, Si: 3.10% , Mn: 0.24%, P: 0.010%, S: 0.001%, sol. A 0.30 mm thick electrical steel sheet containing Al: 0.62% and Sn: 0.03%, the balance being Fe and impurities, was punched, and the dimensional accuracy of the rotor core after punching was investigated. .

  The yield strength of the former electrical steel sheet is controlled in the range of 425 MPa to 435 MPa and the yield strength of the latter electrical steel sheet is controlled in the range of 385 MPa to 395 MPa by adjusting the temperature, tension, and cooling rate of the finish annealing. did. Moreover, the electromagnetic steel sheet was manufactured by changing the peak half width of the (211) plane, respectively, and punching was performed.

  The result is shown in FIG. FIG. 2 is a graph showing the influence of the yield strength on the dimensional accuracy during punching and the peak half width of the (211) plane.

  As shown in FIG. 2, it was found that in the electrical steel sheet having a yield strength of around 430 MPa, when the half width exceeds 0.16 °, the dimensional accuracy of the iron core varies greatly. On the other hand, in the electrical steel sheet having a yield strength of around 390 MPa, a large difference in dimensional accuracy was not recognized depending on the half width. That is, the peak half width of the (211) plane in X-ray diffraction is considered to be an index indicating the magnitude of non-uniform strain applied to the electrical steel sheet after finish annealing.

  For electrical steel sheets with high yield strength, the load at the time of punching increases, but for electrical steel sheets with a large half-value width, the applied uneven strain is large, so the load changes at the place where the mold hits. growing. Thereby, it is considered that there is a possibility that a difference in dimensional accuracy during punching may occur in an electromagnetic steel sheet having a high yield strength and a large half width.

  Therefore, in the present invention, the upper limit of the peak half-value width of the (211) plane in the X-ray diffraction profile of the electrical steel sheet is set to 0.16 °. The peak half width of the (211) plane is desirably 0.15 ° or less, and more desirably 0.14 ° or less. Although the lower limit of the peak half-value width of the (211) plane is not particularly defined, the peak half-value width of the (211) plane even when the magnetic steel sheet is subjected to strain annealing at 750 ° C. for 2 hours after finish annealing. Did not become less than 0.05 °. Therefore, the lower limit of the peak half-value width of the (211) plane may be 0.05 °, for example.

  In addition, the peak half width of the (211) plane in the X-ray diffraction profile of the electromagnetic steel sheet can be controlled by, for example, the furnace tension or thermal history of finish annealing. For example, it is possible to reduce the peak half-value width of the (211) plane of the electrical steel sheet by lowering the furnace tension and the cooling rate of finish annealing.

  The conditions for the punching of the rotor core are as follows. The shape of the rotor core to be punched was the shape of the rotor core of an 8-pole embedded permanent magnet motor, and was a disk shape having an outer diameter of 160 mm. The punching die clearance was 8% of the thickness of the electromagnetic steel sheet to be punched. After punching, measure the outer diameter of the punched rotor core, and consider the maximum difference between the target outer diameter of 160 mm and the measured outer dimension as the outer diameter variation of the rotor core. It was.

  The electromagnetic steel sheet according to the present embodiment has been described in detail above.

  In addition, it does not specifically limit about the manufacturing method of the electromagnetic steel plate which concerns on this embodiment, It is possible to apply the manufacturing process of a general electromagnetic steel plate. That is, hot-rolling a steel slab containing the above-described components, hot-rolled sheet as it is after hot-rolling, or hot-rolled, cold-rolled hot-rolled sheet annealed, The magnetic steel sheet according to this embodiment can be manufactured by applying an insulating film after finish annealing. Note that the cold rolling may be performed by one cold rolling or by two cold rolling sandwiching the intermediate annealing.

  Hereinafter, the electrical steel sheet according to one embodiment of the present invention will be described more specifically with reference to experimental examples. In addition, the experimental example shown below is only an example of the electrical steel sheet according to the present embodiment, and the electrical steel sheet according to the present embodiment is not limited to the experimental example shown below.

Here, a method for measuring magnetic properties such as magnetic flux density B ₅₀ and iron loss W _10/800 shown below is not particularly limited, and for example, a method based on an Epstein test defined in JIS C 2550 Alternatively, a known method such as a single sheet magnetic property test method (SST) defined in JIS C 2556 can be used. The magnetic flux density B ₅₀ is a magnetic flux density at a magnetizing force of 5000 A / m, and the iron loss W _10/800 is an iron loss at a high frequency of 1.0 T and 800 Hz.

  In the following examples, the magnetic properties (for example, magnetic flux density and iron loss) of an electromagnetic steel sheet were evaluated by single-plate magnetic measurement (SST) using a test piece punched into a 55 mm square. In the motor core, magnetic flux flows in various directions on the plate surface of the electromagnetic steel sheet. Therefore, in order to evaluate the magnetic characteristics in the motor core, 0 °, 22.5 °, 45 °, 67. The magnetic properties in 5 directions of 5 ° and 90 ° were measured, and the magnetic properties of the entire circumference were calculated by the following formula. That is, the better the magnetic properties represented by the following formula, the better the non-oriented electrical steel sheet, and the more suitable as the motor iron core.

  Magnetic characteristics = (0 ° characteristics + 2 × 22.5 ° characteristics + 2 × 45 ° characteristics + 2 × 67.5 ° characteristics + 90 ° characteristics) / 8

(Experimental example 1)
A steel slab containing the composition shown in Table 1 below, the balance being Fe and impurities, was heated to 1150 ° C. and then rolled to a thickness of 2.0 mm by hot rolling. Subsequently, the hot-rolled sheet was subjected to hot-rolled sheet annealing at 1000 ° C. for 40 seconds and then rolled to a thickness of 0.25 mm by cold rolling. After the cold-rolled plate was soaked at 1000 ° C. for 1 second, finish annealing was performed at a cooling rate to 900 ° C. of 1 ° C./second or 30 ° C./second. Furthermore, a magnetic steel sheet was manufactured by applying and baking a solution containing an acrylic resin emulsion mainly on a metal phosphate on both surfaces of the steel sheet after the finish annealing to form a composite insulating film.

  For the finish annealing, a floating type continuous annealing furnace capable of running the steel sheet in a levitated state with a furnace floater was used. In this experimental example, the peak half-value width in the X-ray diffraction of the electrical steel sheet was controlled by changing the cooling rate of the finish annealing. Since a steel plate of 900 ° C. or higher has low strength, a low cooling rate at which a temperature difference is less likely to occur within the steel plate surface is less likely to add distortion to the steel plate, and a low peak half width can be secured in X-ray diffraction. . In order to achieve the peak half-value width of the electrical steel sheet according to the present embodiment, the cooling rate of finish annealing is desirably 20 ° C./second or less, and more desirably 15 ° C./second or less.

  In Table 1, “Tr.” Represents that the corresponding element was not intentionally added.

Thereafter, the manufactured electrical steel sheet was punched into 55 mm squares, and the magnetic flux density B ₅₀ and the iron loss W _10/800 were evaluated by single plate magnetic measurement (SST). Regarding the evaluation of dimensional accuracy, as described above, the manufactured magnetic steel sheet was punched into the shape of a rotor core having an outer diameter of 160 mm, and the outer diameter dimension of the punched rotor core and the target outer diameter dimension of 160 mm were The maximum value of the difference between the two was defined as the outer diameter variation of the rotor core. The clearance of the punching die was set to 8% of the thickness of the electromagnetic steel sheet to be punched. When the outer diameter variation was 32 μm or less, the dimensional accuracy was evaluated as good (◯), and when the outer diameter variation was more than 32 μm, the dimensional accuracy was evaluated as poor (x). The obtained results are shown in Table 2 below.

  As shown in Table 2, the test numbers 1, 3, 6, 7, and 9 to 11 in which the composition, peak half width, and yield strength of the steel sheet are within the scope of the present invention are excellent in both iron loss and magnetic flux density. It was found that the dimensional accuracy during punching was good. On the other hand, even though the chemical composition of the steel sheet is within the range of the present invention, the test numbers 2 and 4 in which the peak half-value width of the (211) plane deviates from the range of the present invention is excellent, but the punching process is performed. It was found that the dimensional accuracy was poor. Moreover, it is found that test number 5 in which the Si content of the steel sheet and the Si + Al + 0.5 × Mn content are lower than the range of the present invention and the yield strength is lower than the range of the present invention is inferior in iron loss. It was.

(Experimental example 2)
A steel slab containing the composition shown in Table 3 below, the balance being Fe and impurities, was heated to 1100 ° C. and then rolled to 1.8 mm thickness by hot rolling. Next, the hot-rolled sheet was subjected to hot-rolled sheet annealing at 975 ° C. for 40 seconds and then cold-rolled to a thickness of 0.20 mm. Subsequently, after the cold-rolled plate was soaked at 950 ° C. for 80 seconds, finish annealing was performed at a cooling rate of up to 900 ° C. at 2 ° C./second. Furthermore, a magnetic steel sheet was manufactured by applying and baking a solution containing an acrylic resin emulsion mainly on a metal phosphate on both surfaces of the steel sheet after the finish annealing to form a composite insulating film. For the final annealing, the same floating type continuous annealing furnace as in Experimental Example 1 was used.

  Note that Experimental Example 2 is an experimental example in which the eddy current loss is small and the iron loss is smaller because the magnetic steel sheet is thinner than Experimental Example 1. Referring to Experimental Example 2, it can be seen that the magnetic steel sheet according to one embodiment of the present invention can improve the magnetic properties, mechanical strength, and dimensional accuracy during punching regardless of the plate thickness.

  In Table 3, “Tr.” Represents that the corresponding element was not intentionally added.

Thereafter, the manufactured electrical steel sheet was punched into 55 mm square, and magnetic flux density B ₅₀ and iron loss W _10/800 were evaluated by single-plate magnetic measurement (SST) in the same manner as in Experimental Example 1. Further, the electromagnetic steel plate was punched by the same method as in Experimental Example 1, and the dimensional accuracy was evaluated in the same manner as in Experimental Example 1. The results obtained are shown in Table 4 below.

  As shown in Table 4, test numbers 13, 14 and 15 in which the steel sheet composition, peak half width, and yield strength are within the scope of the present invention are excellent in both iron loss and magnetic flux density, and have dimensional accuracy during punching. Was found to be good. On the other hand, it was found that the test number 12 in which the content of Si + Al + 0.5 × Mn deviated lower than the range of the present invention was inferior in iron loss.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

Claims (2)

In mass%, C: 0.005% or less, Si: 3.0% or more and 4.0% or less, Mn: 3.0% or less, S: 0.004% or less, sol. Al: 0.1% or more and 1.5% or less, P: 0.03% or more and 0.15% or less, with the balance being Fe and impurities,
3.5% ≦ Si + sol. Al + 0.5 × Mn ≦ 5.0%,
The yield strength is 400 MPa or more,
An electrical steel sheet having a peak half width of (211) plane of 0.16 ° or less in an X-ray diffraction profile measured on the steel sheet surface. In mass%, C: 0.005% or less, Si: 3.0% or more and 4.0% or less, Mn: 3.0% or less, S: 0.004% or less, sol. Al: 0.1% to 1.5%, P: 0.03% to 0.15%, Sn: 0.001% to 0.15%, with the balance being Fe and impurities,
3.5% ≦ Si + Al + 0.5 × Mn ≦ 5.0%,
The yield strength is 400 MPa or more,
An electrical steel sheet having a peak half width of (211) plane of 0.16 ° or less in an X-ray diffraction profile measured on the steel sheet surface.

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