JPH1192891A - Silicon steel sheet for electric automobile motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a silicon steel sheet capable of giving low iron loss over a wide range of frequency zone, having high magnetic flux density, and accordingly suitable for use in an electric automobile motor. SOLUTION: This steel sheet has a composition consisting of, by weight, <=0.005% C, 1.5-3.0% Si, 0.05-1.5% Mn, <=0.2% P, <=0.005% (including 0%) N, 0.1-1.0% Al, <=0.001% (including 0%) S, Sb and Sn in the amounts satisfying Sb+Sn/2=0.001 to 0.05%, and the balance essentially Fe and satisfying Si+Al<=3.5%. Further, sheet thickness is regulated to 0.1-0.35 μm, and the average crystalline grain size of the crystalline grains in the steel sheet is regulated to 70-200 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

2. Description of the Related Art Motors for electric vehicles are used in a very wide frequency range of several hundreds to 1 KHz. For this reason, excellent magnetic characteristics are required from a low frequency range to a high frequency range. However, conventionally, an electromagnetic steel sheet that can obtain excellent characteristics in a high frequency range of about 1 KHz has been used. In magnetic steel sheets for such high-frequency applications, from the viewpoint of reducing eddy current loss,
The steel sheet is made thinner, the specific resistance is increased, and the crystal grains are made finer.

[0002] As such an example, Japanese Patent Application Laid-Open No. Hei 3-2234 has been disclosed.
No. 45 discloses that the Si + Al content is set to 2.0 to 4.0% and the plate thickness is set to 0.1 to 4.0%.
The invention of a high-frequency non-oriented electrical steel sheet used at 700 Hz or higher with a crystal grain size of 0.25 mm and a crystal grain size of 5 to 60 μm is disclosed.

[0003]

However, in the present invention,
In order to obtain good iron loss in the high frequency range of about 700 Hz, the crystal grain size is about 5 to 60 μm, so there is a problem that good iron loss cannot be obtained in the low and medium frequency range of about 50 to 200 Hz. is there. Therefore, such an electromagnetic steel sheet is not suitable as a core material for a motor of an electric vehicle that requires excellent iron loss characteristics from a low frequency range to a high frequency range.

[0004] Further, in the conventional method of increasing the specific resistance by increasing the amounts of Si and Al to about 4% to reduce the iron loss, the iron loss reduction effect in a wide frequency range can be obtained. In addition, since the saturation magnetic flux density decreases, it is not desirable for a motor requiring torque, such as a motor for an electric vehicle.

As described above, it is difficult to obtain a material having a high magnetic flux density and a low iron loss in a wide frequency range in the prior art.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has a low iron loss in a wide frequency band and a high magnetic flux density. Therefore, the present invention is used for a motor of an electric vehicle. It is an object of the present invention to provide an electromagnetic steel sheet that is suitable for use.

[0007]

The gist of the present invention is that S ≦ 0.0
01%, and further, by adding a predetermined amount of Sb or Sn to a steel sheet having a thickness of 0.1 to 0.35 mm and, in addition, by setting the average grain size of the crystal grains in the steel sheet to a predetermined range, the electric vehicle motor is required. To obtain an electromagnetic steel sheet having a high magnetic flux density and a low iron loss in a wide frequency range.

[0008] That is, the above-mentioned problem is that C: 0.
005% or less, Si: 1.5-3.0%, Mn: 0.05-1.5%, P: 0.
2% or less, N: 0.005% or less (including 0), Al: 0.1 to 1.0
%, Si + Al ≦ 3.5%, S: 0.001% or less (including 0), Sb +
Sn / 2 = 0.001 to 0.05%, the balance is substantially Fe, the thickness of the steel sheet is 0.1 to 0.35 mm, and the average grain size of the crystal grains in the steel sheet is 70 to 200 μm. Solved by magnetic steel sheets.

In addition, the range of Sb + Sn / 2 is set to 0.001 to 0.005%.
By limiting to, a steel sheet with lower iron loss can be obtained.

Here, "the balance is substantially Fe" means that in addition to unavoidable impurities, those containing trace amounts of other elements within the range not impairing the effects of the present invention are also included in the present invention. It is included in the range.

In the present specification, unless otherwise specified,% indicating an element contained in a steel sheet indicates weight%, and ppm means weight p.
Indicates pm.

(Circumstances leading to the invention) The present inventors first investigated the effect of the amount of S on iron loss.
26%, Si: 2.80%, Mn: 0.21%, P: 0.01%, Al: 0.32
%, N: 0.0015% and the S amount was changed in the range of tr. To 15 ppm. The steel was vacuum melted in a laboratory, hot rolled, pickled, and then 75% H _2.
The hot rolled sheet was annealed at 830 ° C. for 3 hours in a -25% N ₂ atmosphere.

Subsequently, the hot-rolled annealed sheet was made to have a sheet thickness of 0.5
Was cold rolled to 0.35 mm, 90 with 10% H ₂ -90% N ₂ atmosphere
Finish annealing was performed at 0 ° C for 2 minutes. The magnetic measurement was performed by the 25 cm Epstein method.

In general, an electric vehicle is excited at about 1.5 T because a torque is required in a low frequency range of about 50 Hz, and is driven at about 1.0 T because a torque is not so required in a high frequency range of about 400 Hz. You. For this reason, at a frequency of 50 Hz, the iron loss W when magnetized to 1.5 T
Evaluation was performed at _15/50 , and at a frequency of 400 Hz, evaluation was performed using iron loss W _10/400 when magnetized to _{1.0 T.} Figure 1 shows the thickness of 0.5mm
2 shows the relationship between the S content of the material _{No. 1} and the iron _losses W _15/50 and W _10/400 .

FIG. 1 shows that the iron loss W _15/50 at a frequency of 50 Hz in a 0.5 mm material is significantly reduced when S ≦ 10 ppm.

On the other hand, it can be seen that the iron loss W _{10/400 at} 400 Hz increases when the S content decreases. In order to investigate the cause of the change in iron loss due to the decrease in the amount of S, the structure was observed with an optical microscope. As a result, it was clarified that the crystal grains were as coarse as about 100 μm when S ≦ 0.001%. This is considered to be because the MnS in the steel was reduced.

From this structural change, the S content dependence of iron loss at frequencies of 50 Hz and 400 Hz can be understood as follows.
Generally, iron loss can be divided into hysteresis loss and eddy current loss. It is known that when the crystal grain size increases, the hysteresis loss decreases and the eddy current loss increases. At a frequency of 50 Hz, the hysteresis loss is a dominant factor of the iron loss. Therefore, the hysteresis loss is reduced due to the reduction of S and the resulting coarsening of the crystal grains, and the iron loss is reduced. On the other hand, at a frequency of 400 Hz, the eddy current loss is the dominant factor of the iron loss. Therefore, the reduction in S and the coarsening of the crystal grains resulting therefrom increase the eddy current loss and increase the iron loss.

From the above, it can be seen that reducing S in a 0.5 mm material is effective in reducing iron loss in a low frequency range, but is counterproductive in reducing iron loss in a high frequency range.

FIG. 2 shows the relationship between the S content of 0.35 mm material and iron loss. From Fig.2, iron loss W at a frequency of 50Hz in 0.35mm material
_It can be seen that _15/50 is significantly reduced when S ≦ 10 ppm, like the 0.5 mm material.

However, unlike the result of the 0.5 mm material, it can be seen that the iron loss W _{10/400 at} 400 Hz also decreases when the S content decreases. This is because the eddy current loss is significantly reduced in 0.35 mm material compared to 0.5 mm material due to the reduced thickness, and 400 Hz
This is because the reduction in hysteresis loss due to coarsening of the crystal grain size also reduces the total iron loss.

From the above, it can be seen that at a plate thickness of 0.35 mm or less, the reduction of S significantly reduces iron loss from a low frequency range to a high frequency range. For this reason, in the present invention, the range of the amount of S is 10 ppm or less, the plate thickness is 0.35 mm or less,
Each is limited.

Further, the decrease in iron loss from the low frequency range to the high frequency range due to the reduction of S was remarkably recognized as the thickness became thinner in an electromagnetic steel sheet having a thickness of 0.35 mm or less. But,
If the sheet thickness is less than 0.1 mm, it becomes difficult to perform cold rolling, and furthermore, the labor required for laminating steel sheets increases, so the sheet thickness is set to 0.1 mm or more in the present invention.

Next, a method for further reducing iron loss in a 0.35 mm material was examined. As a method for reducing iron loss, it is generally effective to increase the amounts of Si and Al and increase the specific resistance. However, in a motor for an electric vehicle, an increase in Si and Al is not desirable because it leads to a decrease in torque. Therefore, a method other than increasing Si and Al was examined.

In FIG. 2, when the amount of S is 10 ppm or less, the iron loss decreases gradually. Even if the amount of S is further reduced, the iron loss is about ₁₅ W / ₅₀ at _2.3 W / kg and W _10/400.
Only about 18.5W / kg.

The inventors of the present invention have considered that the reason why the reduction of iron loss is inhibited by the extremely low S material of S ≦ 10 ppm may be due to unknown factors other than MnS, and observed the structure with an optical microscope. Was. As a result, a remarkable nitride layer was recognized on the surface layer of the steel sheet in the region of S ≦ 10 ppm. In contrast, in the region where S> 10 ppm, the nitrided layer was slight. It is considered that this nitrided layer was formed during hot rolled sheet annealing and finish annealing performed in a nitriding atmosphere.

The cause of the acceleration of the nitridation reaction accompanying the reduction of S is considered as follows. That is, since S is an element which is easily concentrated on the surface and the grain boundaries, S> 10 ppm
It is probable that S was concentrated on the steel sheet surface in the region of (1) and suppressed the adsorption of nitrogen during annealing, while in the region of S ≦ 10 ppm, the effect of suppressing the adsorption of nitrogen by S was reduced.

The present inventors have considered that the nitride layer which is remarkably generated in this extremely low S material may suppress the decrease in iron loss. Under such a concept, the present inventors have found that if an element capable of suppressing nitrogen adsorption and adding an element that does not hinder the excellent grain growth of the ultra-low S material can be added, the iron of the ultra-low S material With the idea that losses could be further reduced,
As a result of various studies, it was found that the addition of Sb and Sn was effective.

FIG. 3 shows that the components of the sample shown in FIG.
The results of a test performed under the same conditions for a sample to which Sb of ppm was added are shown. Focusing on the iron loss reduction effect of Sb,
In the region of S> 10 ppm, iron loss is reduced to W _15/50 by adding Sb.
Although it decreases only about _0.2 to 0.3 W / kg at about ₀₂ to 0.04 W / kg and W _10/400 , in the region of S ≦ 10 ppm, the iron loss is about 0.20 to 0.30 W / kg at W _15/50 by adding Sb. , 1.5 for W _10/400
When the amount of S is small, the iron loss reducing effect of Sb is remarkably recognized. In this sample, no nitrided layer was observed regardless of the S content. This is probably because Sb concentrated in the surface layer of the steel sheet and suppressed the adsorption of nitrogen.

From the above, the extremely low S material having a thickness of 0.35 mm can be obtained.
It has been clarified that the addition of Sb makes it possible to significantly reduce iron loss over a wide frequency range without lowering the magnetic flux density.

Next, to investigate the optimum amount of Sb, C:
0.0026%, Si: 2.75%, Mn: 0.30%, P: 0.02%, Al:
0.35%, S: 0.0004%, N: 0.0020%, Sb amount tr. ~ 700p
The steel changed in the range of pm was melted in a laboratory in vacuum, hot-rolled, and then pickled. 75% H ₂ -25
% N subjected to hot band annealing of 830 ° C. × 3 hr in ₂ atmosphere, the thickness
Was cold rolled to 0.35 mm, 90 with 10% H ₂ -90% N ₂ atmosphere
Finish annealing was performed at 0 ° C for 2 minutes. FIG. 4 shows the Sb content and the iron loss W _15/50 and W of the sample thus obtained.
_It shows the _10/400 relationship.

FIG. 4 shows that iron loss decreases in the region where the amount of Sb added is 10 ppm or more, and W _15/50 = 2.0 W / kg and W _10/400 = 17 W /
It can be seen that kg is achieved. However, when Sb is further added and Sb> 50 ppm, the iron loss increases gradually with the increase in the amount of Sb.

In order to investigate the cause of the increase in iron loss in the region where Sb> 50 ppm, the structure was observed with an optical microscope. As a result, although no surface nitride layer was observed, the average crystal grain size was slightly smaller. Although the cause is not clear, it is considered that since Sb is an element that is easily segregated at the grain boundary, the grain growth property is reduced by the grain boundary drag effect of Sb.

However, even when Sb is added up to 700 ppm, the iron loss is better than that of Sb-free steel. From the above, Sb is 10
ppm or more, and the upper limit is set to 500 ppm due to cost issues.
From the viewpoint of iron loss, the content is desirably 10 ppm or more and 50 ppm or less, and more desirably 20 ppm or more and 40 ppm or less.

Since Sn is also an element that segregates on the surface like Sb,
It is considered that the same nitriding suppression effect as that of Sb can be obtained.
Therefore, to investigate the optimum amount of Sn, C: 0.0020
%, Si: 2.85%, Mn: 0.31%, P: 0.02%, Al: 0.30
%, S: 0.0003%, N: 0.0015% and the amount of Sn was changed in the range of tr. To 1400 ppm.
Pickling was performed. Subsequently, 75% H ₂ -25% N ₂
Hot rolled sheet annealing at 830 ° C x 3hrs in atmosphere, 0.35m thick
cold rolled to 900 m in a 10% H ₂ -90% N ₂ atmosphere
Finish annealing was performed for 2 minutes.

FIG. 5 shows the sample thus obtained.
It shows the relationship between the amount of Sn and W _15/50 and W _10/400 .

FIG. 5 shows that iron loss decreases in the region where the amount of Sn added is 20 ppm or more, and W _15/50 = 2.0 W / kg and W _10/400 = 17 W /
It can be seen that kg is achieved. However, when Sn is further added and Sn> 100 ppm, the iron loss also increases gradually with an increase in the amount of Sn. However, Sn is 1400pp
Even when added up to m, the iron loss is better than that of Sn-free steel.

The difference between the effects of Sn and Sb on iron loss can be understood as follows. That is, since Sn has a segregation coefficient smaller than that of Sb, an amount about twice as large as that of Sb is required to suppress nitriding by surface segregation. For this reason, Sn is 20p
The addition of pm or more will reduce iron loss. on the other hand,
The addition amount at which iron loss starts to increase due to the drag effect due to the grain boundary segregation of Sn is also about twice, since the segregation coefficient of Sn is smaller than that of Sb. For this reason, iron loss will increase moderately by addition of 100 ppm or more of Sn.

From the above, Sn is set to 20 ppm or more, and the upper limit is set to 1000 ppm from the viewpoint of cost. From the viewpoint of iron loss, the content is desirably 20 ppm or more and 100 ppm or less, and more desirably 30 ppm or more and 90 ppm or less.

As described above, the mechanism by which Sb and Sn suppress nitriding is the same. For this reason, even when Sb and Sn are added simultaneously, the same nitriding suppression effect can be obtained.
However, in order for Sn to exhibit the same effect as Sb, 2
A double addition amount is required. Therefore, when Sb and Sn are added simultaneously, the content of Sb + Sn / 2 is set to 0.001% or more and 0.05% or less, and more preferably 0.001% or more and 0.005% or less.

Next, in order to investigate the optimum grain size of the crystal grains of the steel sheet having the component system of the present invention, C: 0.0026%, S:
i: 2.65%, Mn: 0.18%, P: 0.01%, Al: 0.30%,
Steel containing 0.0004% of S, 0.0015% of N, and 0.004% of Sb was melted in a laboratory in a vacuum, hot-rolled, and then pickled. Subsequently, the hot-rolled sheet was annealed at 830 ° C. for 3 hours in 75% H ₂ -25% N ₂ and cold-rolled to a sheet thickness of 0.35 mm. Then, the finish annealing at 750 to 1100 ° C. for 2 minutes in 10% H ₂ -90% N ₂ greatly changed the crystal grain size after the finish annealing.

[0041] Figure 6 illustrates the manner relation average particle diameter and the iron loss W _15/50 and W _10/400 samples obtained. As shown in FIG. 6, when the average particle size is less than 70 μm, the _iron loss value W _15/50 at a frequency of 50 Hz sharply increases, while when the average particle size exceeds 200 μm, the _iron loss value W _{10/400 at a} frequency of 400 Hz is _obtained.
It can be seen that increases rapidly. From this, in the present invention, the average crystal grain size of the crystal grains of the steel sheet is 70 ~ 200μ
m. More preferably, the average crystal grain size is 100 to 180 μm.

(Reasons for Limiting Other Components) Next, reasons for limiting other components will be described. C was made 0.005% or less because of the problem of magnetic aging. Since Si is an element effective for increasing the specific resistance of the steel sheet, 1.5% or more is added. On the other hand, if it exceeds 3.0%, the magnetic flux density decreases with a decrease in the saturation magnetic flux density, so the upper limit was made 3.0%. Mn is
In order to prevent red hot brittleness during hot rolling, 0.05% or more is necessary. However, when it exceeds 1.5%, the magnetic flux density is reduced. P is an element necessary for improving the punching property of the steel sheet, but if added in excess of 0.2%, the steel sheet becomes brittle, so P was set to 0.2% or less. N is set to 0.005% or less because the precipitation amount of AlN increases when the content is large, and even when AlN becomes coarse, the grain growth decreases and the iron loss increases. When Al is added in a small amount, fine AlN is generated and the magnetic characteristics are deteriorated. Therefore, it is necessary to set the lower limit to 0.1% and coarsen AlN. on the other hand,
If it exceeds 1.0%, the magnetic flux density decreases, so the upper limit is 1.0
% Or less. However, when the amount of Si + Al exceeds 3.5%, the magnetic flux density decreases and the exciting current increases. Therefore, the content of Si + Al is set to 3.5% or less.

(Production method) In the present invention, S, Sb, S
As long as n is within a predetermined range, the manufacturing method may be an ordinary method for manufacturing an electromagnetic steel sheet. That is, the molten steel blown in the converter is degassed, adjusted to a predetermined component, and subsequently cast,
Hot rolling is performed. The finish annealing temperature and the winding temperature at the time of hot rolling do not need to be particularly defined, and may be ordinary temperatures. In addition, hot-rolled sheet annealing after hot-rolling may be performed, but is not essential. Next, a final annealing is performed after a predetermined thickness is obtained by one cold rolling or two or more cold rollings including an intermediate annealing. The crystal grain size defined in the present invention is obtained by changing the temperature of the final annealing.

[0044]

EXAMPLES Using the steel shown in Table 1, after degassing by blowing in a converter, the steel was adjusted to predetermined components and cast.
After the slab was heated at 1150 ° C. for 1 hour, hot rolling was performed to a thickness of 2.0 mm. The hot rolling finishing temperature was 750 ° C, and the winding temperature was 610 ° C. Next, the hot-rolled sheet was pickled and subjected to hot-rolled sheet annealing under the conditions shown in Tables 2 and 3. The hot rolled sheet annealing atmosphere was 75% H ₂ -25% N ₂ . After that, the plate thickness 0.1-0.5mm
Cold rolling was performed until the finish annealing conditions shown in Tables 2 and 3 were reached. Finish annealing atmosphere is 10% H ₂ -90% N ₂
And

The magnetic measurement was performed on a 25 cm Epstein test piece (L +
C) / 2. Tables 2 and 3 also show the magnetic properties of each steel sheet. In Tables 1 to 3, No. indicates the steel sheet number, which is common to each table.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3]

In Tables 1 to 3, the steel sheets No. 1 to No. 31 have a thickness of 0.35 mm, and the steel sheets No. 33 to No. 36 have a thickness of 0.3 mm.
The thickness of the steel plates of 20 mm, No. 36 to No. 38 is 0.50 mm. When compared at the same sheet thickness, for those having a sheet thickness of 0.35 mm, the steel sheets of No. 1 to No. ₁₆ which are examples of the present invention all have iron losses W _15/50 and W _10/400. Is low.

On the other hand, the steel sheet of No. 17 has a higher W _15/50 value than the steel of the present invention because the crystal grain size is below the range of the present invention. Also, No. 18 steel plate
Since the crystal grain size exceeds the range of the present invention, the iron loss W
The value of _10/400 is higher than the steel of the present invention.

The steel sheet No.19 is, S, Sb + Sn / 2 , the crystal grain size is outside the scope of the present invention, the iron loss W _15/50 and W
_10/400 is higher. In the steel sheet No. 20, since Sb + Sn / 2 is out of the range of the present invention, iron loss W _15/50 and W
_10/400 is higher. Since the steel sheet No. 21 has a crystal grain size of Sb + Sn / 2 out of the range of the present invention, the iron loss W
_15/50 and W _10/400 are higher.

In the steel sheet No. 22, since Si + Al and Sb + Sn / 2 are out of the range of the present invention, the iron _losses W _15/50 and W _10/400
At the same time is high, the magnetic flux density B ₅₀ is small. The steel sheet No. 23 has high iron _losses W _15/50 and W _10/400 because Si is below the range of the present invention. In the steel sheet No. 24, since Si and Si + Al are beyond the range of the present invention, the iron _losses W _15/50 and W _10/400 are low, but the magnetic flux density B ₅₀ is small. No.25 steel plate is Si + Al
_Exceeds the range of the present invention, the iron _losses W _15/50 and W _10/400 are low, but the magnetic flux density B ₅₀ is low.

Since the steel sheet of No. 26 has Al and the crystal grain size outside the range of the present invention, not only the iron loss W _15/50 and W _10/400 are increased but also the magnetic flux density B ₅₀ Is getting smaller. In the steel sheet No. 27, since Al and Si + Al are out of the range of the present invention, the iron _losses W _15/50 and W _10/400 are low, but the magnetic flux density B ₅₀ is small. The steel sheet No. 28 has high core loss W _15/50 and W _10/400 because the crystal grain size is out of the range of the present invention. In addition, since Mn is lower than the range of the present invention, there is a problem of red hot brittleness during hot rolling. N
steel o.29, since Mn is higher than the range of the present invention, the magnetic flux density B ₅₀ is small.

The steel sheet No. 30 has high core loss W _15/50 and W _10/400 because the crystal grain size is out of the range of the present invention. Since the range of C is out of the range of the present invention, there is a problem of magnetic aging. In the steel sheet No. 31, since N and the crystal grain size are out of the range of the present invention, the iron loss W
_15/50 and W _10/400 are higher.

Regarding the steel sheet having a thickness of 0.20 mm, the steel sheets of the present invention No. 32 and No. 33 have the iron loss W _15/50 and the iron loss W _15/50 compared with the comparative steels No. 34 and No. 35. W _10/400 is low. No. 34 steel sheet, S, Sb + Sn / 2, and crystal grain size are all out of the range of the present invention, and No. 35 steel sheet Sb + Sn / 2 is out of the range of the present invention. Also iron loss W _15/50 and W _10/400
Is high.

The steel sheets No. 36 to No. 38, each having a thickness of 0.5 mm, have high iron losses W _15/50 and W _10/400 .

[0057]

As described above, in the present invention, the components of the steel sheet are expressed by weight%, C: 0.005% or less, Si:
1.5-3.0%, Mn: 0.05-1.5%, P: 0.2% or less, N: 0.
005% or less, Al: 0.1 to 1.0%, Si + Al ≦ 3.5%, S: 0.001
% Or less, Sb + Sn / 2 = 0.001 to 0.05%, the balance is specified to be substantially Fe, and the plate thickness is 0.1 to 0.35 mm.
And the average grain size of the crystal grains in the steel sheet is 70
Since the thickness is defined to be about 200 μm, it is possible to obtain a steel sheet having a high magnetic flux density and a low iron loss in a wide frequency range, which is suitable for a motor core material for an electric vehicle. In addition, lower iron loss can be obtained by limiting the range of Sb + Sn / 2 to 0.001 to 0.005%.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the amount of S in a 0.5 mm material and iron loss after finish annealing.

FIG. 2 is a graph showing the relationship between the amount of S in a 0.35 mm material and iron loss after finish annealing.

FIG. 3 is a diagram showing the relationship between the amounts of S and Sb and iron loss after finish annealing.

FIG. 4 is a graph showing the relationship between the amount of Sb and iron loss after finish annealing.

FIG. 5 is a graph showing the relationship between the amount of Sn and iron loss after finish annealing.

FIG. 6 is a diagram showing a relationship between an average crystal grain size and iron loss after finish annealing.

Claims (2)

[Claims] (1) C: 0.005% or less by weight, Si: 1.5 to
3.0%, Mn: 0.05-1.5%, P: 0.2% or less, N: 0.005%
The following (including 0): Al: 0.1 to 1.0%, Si + Al ≦ 3.5%,
S: 0.001% or less (including 0), Sb + Sn / 2 = 0.001 to 0.05
%, The balance being substantially Fe, and having a thickness of 0.1 to 0.3.
Electromagnetic steel sheet for motors of electric vehicles, which is 5 mm and has an average crystal grain size of 70 to 200 μm in the steel sheet. 2. C: 0.005% or less in weight%, Si: 1.5 to
3.0%, Mn: 0.05-1.5%, P: 0.2% or less, N: 0.005%
The following (including 0): Al: 0.1 to 1.0%, Si + Al ≦ 3.5%,
S: 0.001% or less (including 0), Sb + Sn / 2 = 0.001 to 0.005
%, The balance being substantially Fe, and having a thickness of 0.1 to 0.3.
Electromagnetic steel sheet for motors of electric vehicles, which is 5 mm and has an average crystal grain size of 70 to 200 μm in the steel sheet.