U.S. patent application number 13/812430 was filed with the patent office on 2013-06-13 for method of producing non-oriented electrical steel sheet.
This patent application is currently assigned to JFE STEEL CORPORATION. The applicant listed for this patent is Masaaki Kohno, Yoshihiko Oda, Yoshiaki Zaizen. Invention is credited to Masaaki Kohno, Yoshihiko Oda, Yoshiaki Zaizen.
Application Number | 20130146187 13/812430 |
Document ID | / |
Family ID | 45772713 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130146187 |
Kind Code |
A1 |
Zaizen; Yoshiaki ; et
al. |
June 13, 2013 |
METHOD OF PRODUCING NON-ORIENTED ELECTRICAL STEEL SHEET
Abstract
Disclosed is a method for producing a non-oriented magnetic
steel sheet, wherein a steel slab that consists of 0.01-0.1 mass %
of C, 4 mass % or less of Si, 0.05-3 mass % of Mn, 3 mass % or less
of Al, 0.005 mass % or less of S, 0.005 mass % or less of N and the
balance made up of Fe and unavoidable impurities is subjected to
hot rolling, cold rolling and final annealing. By carrying out the
final annealing, while setting the average heating rate during the
heating to 100.degree. C./sec or more and setting the soaking
temperature within the temperature range of 750-1100.degree. C., a
non-oriented magnetic steel sheet that has extremely increased
magnetic flux density in the rolling direction of the steel sheet
is advantageously produced.
Inventors: |
Zaizen; Yoshiaki; (Tokyo,
JP) ; Oda; Yoshihiko; (Tokyo, JP) ; Kohno;
Masaaki; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Zaizen; Yoshiaki
Oda; Yoshihiko
Kohno; Masaaki |
Tokyo
Tokyo
Tokyo |
|
JP
JP
JP |
|
|
Assignee: |
JFE STEEL CORPORATION
Tokyo
JP
|
Family ID: |
45772713 |
Appl. No.: |
13/812430 |
Filed: |
August 25, 2011 |
PCT Filed: |
August 25, 2011 |
PCT NO: |
PCT/JP2011/069136 |
371 Date: |
January 25, 2013 |
Current U.S.
Class: |
148/645 |
Current CPC
Class: |
C21D 8/1255 20130101;
C22C 38/00 20130101; C22C 1/02 20130101; C21D 8/0205 20130101; C21D
8/1244 20130101; C21D 8/12 20130101; C21D 8/1272 20130101; C21D
2201/05 20130101 |
Class at
Publication: |
148/645 |
International
Class: |
C21D 8/02 20060101
C21D008/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2010 |
JP |
2010-191714 |
Claims
1. A method of producing a non-oriented electrical steel sheet by
subjecting a steel slab comprising C: 0.01-0.1 mass %, Si: not more
than 4 mass %, Mn: 0.05-3 mass %, Al: not more than 3 mass %, S:
not more than 0.005 mass %, N: not more than 0.005 mass % and the
remainder being Fe and inevitable impurities to hot rolling, cold
rolling and finish annealing, characterized in that the finish
annealing is conducted under conditions that an average temperature
rising rate during the heating is not less than 100.degree. C./sec
and a soaking temperature is a temperature range of
750-1100.degree. C.
2. A method of producing a non-oriented electrical steel sheet
according to claim 1, wherein the steel slab further contains at
least one of Sn and Sb in an amount of 0.005-0.1 mass %,
respectively.
3. A method of producing a non-oriented electrical steel sheet
according to claim 1, wherein decarburization annealing is
conducted after the finish annealing.
4. A method of producing a non-oriented electrical steel sheet
according to claim 2, wherein decarburization annealing is
conducted after the finish annealing.
Description
TECHNICAL FIELD
[0001] This invention relates to a method of producing a
non-oriented electrical steel sheet, and more particularly to a
method of producing a non-oriented electrical steel sheet with an
excellent magnetic flux density in a rolling direction of the steel
sheet.
RELATED ART
[0002] Recently, it is strongly required to render electric
equipments into higher efficiency and downsizing in universal
current of reducing energy inclusive of power. As a result, even in
non-oriented electrical steel sheets widely used as a core material
or the like of the electric equipment, it becomes an essential
agenda to improve magnetic property or to attain a higher magnetic
flux density and a lower iron loss for achieving the downsizing and
high efficiency of the electric equipment.
[0003] For such requirements on the non-oriented electrical steel
sheet, it has hitherto been attempted to make the magnetic flux
density higher by selecting appropriate alloying elements to be
added and further increasing a crystal grain size before cold
rolling or optimizing a cold rolling reduction, while it has been
attempted to make the iron loss lower by adding an element for
increasing electrical resistance or reducing a sheet thickness.
[0004] In a driving motor for hybrid automobiles and so on, a
segment core is adopted from a viewpoint of an improved yield. The
segment core is formed by dividing the core into several parts
instead that the core is punched out as a single part from a raw
steel sheet as usual, and punching these parts so as to render a
longitudinal direction of a teeth in each part into a rolling
direction of the steel sheet and assembling the punched parts into
a core. In the segment core, the longitudinal direction of the
teeth concentrating the magnetic flux is the rolling direction of
the electrical steel sheet, so that the properties of the
electrical steel sheet in the rolling direction become very
important for attaining the improvement of properties of the
motor.
[0005] As a material enhancing the magnetic flux density in the
rolling direction is mentioned a grain oriented electrical steel
sheet having a Goss orientation aligned in the rolling direction.
However, the grain oriented electrical steel sheet is produced
through a secondary recrystallization process, so that the
production cost is high and the sheet is not substantially used as
the segment core actually. Therefore, it is considered that it
allows to use cheap, non-oriented electrical steel sheets as an
optimum material for the segment core if the magnetic flux density
in the rolling direction thereof can be improved.
[0006] As a technique responding such a requirement, for example,
Patent Document 1 discloses a method of producing a non-oriented
electrical steel sheet comprising hot rolling a steel having C: not
more than 0.002 mass %, Si: not less than 0.1 mass % but less than
0.8 mass %, Al: 0.3-2.0 mass %, Mn: 0.1-1.5 mass % and Si+2Al-Mn:
not less than 2%, subjecting a hot band annealing to render an
average crystal grain size into not less than 300 .mu.m, performing
a single cold rolling at a rolling reduction of 85-95% for a final
sheet thickness and then performing a finish annealing at
700-950.degree. C. for 10 seconds to 1 minute.
[0007] Also, Patent Document 2 discloses a non-oriented electrical
steel sheet for a segment core having a thickness of 0.15-0.3 mm
formed by subjecting a hot rolled steel sheet having C: not more
than 0.005 mass %, Si: 2-4 mass % and Al: more than 1 mass % but
not more than 2 mass % to an annealing, a single cold rolling and
further a recrystallization annealing to provide a
recrystallization structure having an average crystal grain size of
40-200 .mu.m and magnetic property satisfying a relationship of a
magnetic flux density B.sub.50(C) in 90.degree. direction
(C-direction) relative to the rolling direction (L-direction), a
magnetic flux density B.sub.50(X) in 45.degree. direction
(X-direction) relative to the rolling direction (L-direction) and a
thickness t (mm) of the following equation:
B.sub.50(C)/B.sub.50(X).gtoreq.-0.5333.times.t.sup.2+0.3907.times.t+0.94-
5.
PRIOR ART DOCUMENTS
Patent Documents
[0008] Patent Document 1: JP-A-2004-332042
[0009] Patent Document 2: JP-A-2008-127600
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0010] According to the method of Patent Document 1, a magnetic
steel sheet having excellent magnetic property in the rolling
direction and vertical direction thereof can be obtained by
controlling the crystal grain size after the hot band annealing and
the rolling reduction in the cold rolling. However, this method has
problems in the productivity and cost because it is required to
reduce impurity content in steel remarkably and to conduct the hot
band annealing at a higher temperature (for example,
1000-1050.degree. C.) for obtaining a crystal grain size before the
cold rolling of not less than 300 .mu.m . The method of Patent
Document 2 has problems in the productivity and cot because the
temperature of the hot band annealing is necessary to be high
(higher than 900.degree. C., for example, 920-1100.degree. C.) and
also it is required to add a greater amount of Al.
[0011] The invention is made in view of the above-mentioned
problems of the conventional techniques and is to propose an
advantageous method of producing a non-oriented electrical steel
sheet which can increase the magnetic flux density in the rolling
direction of the steel sheet considerably.
Means for Solving Problems
[0012] The inventors have made various studies for solving the
above problems. As a result, it has been found that the magnetic
property in the rolling direction of the steel sheet are
considerably improved by heating a cold rolled steel sheet
containing an adequate amount or more of C and rolled to a final
thickness at a rate faster than a temperature rising rate in the
conventional finish annealing, and the invention has been
accomplished.
[0013] That is, the invention is a method of producing a
non-oriented electrical steel sheet by subjecting a steel slab
comprising C: 0.01-0.1 mass %, Si: not more than 4 mass %, Mn:
0.05-3 mass %, Al: not more than 3 mass %, S: not more than 0.005
mass %, N: not more than 0.005 mass % and the remainder being Fe
and inevitable impurities to hot rolling, cold rolling and finish
annealing, characterized in that the finish annealing is conducted
under conditions that an average temperature rising rate during the
heating is not less than 100.degree. C./sec and a soaking
temperature is a temperature range of 750-1100.degree. C.
[0014] The steel slab used in the production method of the
invention is preferable to further contain at least one of Sn and
Sb in an amount of 0.005-0.1 mass %, respectively.
[0015] In the production method of the invention, it is preferable
to conduct decarburization annealing after the finish
annealing.
Effect of the Invention
[0016] According to the invention, there can be provided
non-oriented electrical steel sheets having excellent magnetic
property in the rolling direction of the steel sheet. Therefore,
the invention largely contributes to improve the efficiency of
motor or transformer by applying the steel sheet to applications
such as segment core, core for transformer and the like requiring
excellent magnetic property in the rolling direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a graph showing an influence of a temperature
rising rate in finish annealing (horizontal axis: .degree. C./sec)
on a magnetic flux density B.sub.50-L in rolling direction
(vertical axis: T).
[0018] FIG. 2 is a graph showing an influence of a C content
(horizontal axis: mass %) on a magnetic flux density B.sub.50-L in
rolling direction (vertical axis: T).
EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0019] At first, the invention will be described with respect to
experiments for the development of the invention.
[0020] In order to research an influence of a temperature rising
rate in the heating for finish annealing on a magnetic flux density
in a rolling direction of a steel sheet, a non-oriented electrical
steel sheet is prepared by heating a steel slab containing C:
0.0025 mass % or 0.02 mass % and further having a fundamental
composition of Si: 3.3 mass %, Mn: 0.1 mass %, Al: 0.001 mass %, N:
0.0019 mass % and S: 0.0010 mass % at 1100.degree. C. for 30
minutes and hot rolling it to form a hot rolled sheet having a
thickness of 2.6 mm, subjecting a hot band annealing at
1000.degree. C. for 30 seconds, subjecting to a single cold rolling
to form a cold rolled sheet having a final thickness of 0.35 mm,
heating the cold rolled sheet at a temperature rising rate of
30-300.degree. C./sec in a direct power heating furnace to conduct
finish annealing of 900.degree. C..times.10 seconds, and then
conducting decarburization annealing at 850.degree. C. in an
atmosphere having a dew point of 30.degree. C. for 30 seconds.
[0021] From each of the thus obtained non-oriented electrical steel
sheets is cut out a specimen of 180 mm in rolling direction
(L-direction).times.30 mm in vertical direction to the rolling
direction (C-direction), and a magnetic flux density in L-direction
B.sub.50-L of the specimen is measured by a single sheet magnetic
test to obtain results shown in FIG. 1. It can be seen from FIG. 1
that the magnetic flux density in the rolling direction can be
increased by heating the cold rolled sheet containing C: 0.02 mass
% at a temperature rising rate of not less than 100.degree. C./sec
to conduct finish annealing.
[0022] In order to research an influence of a C content on a
magnetic flux density in a rolling direction of a steel sheet, a
non-oriented electrical steel sheet is prepared by heating a steel
slab containing C: 0.005-0.5 mass %, Si: 3.3 mass %, Mn: 0.15 mass
%, Al: 0.001 mass %, N: 0.0022 mass %, S: 0.0013 mass % at
1100.degree. C. for 30 minutes, hot rolling to form a hot rolled
sheet having a thickness of 2.3 mm, subjecting a hot band annealing
at 1000.degree. C. for 30 seconds and further to a single cold
rolling to form a cold rolled sheet having a final thickness of
0.35 mm, heating the cold rolled sheet at a temperature rising rate
of 20.degree. C./sec or 300.degree. C./sec in a direct power
heating furnace to conduct finish annealing of 950.degree.
C..times.10 seconds, and thereafter subjecting to a decarburization
annealing at 850.degree. C. in an atmosphere having a dew point of
30.degree. C. for 30 seconds.
[0023] From each of the thus obtained non-oriented electrical steel
sheets is cut out a specimen of 180 mm in rolling direction
(L-direction).times.30 mm in vertical direction to the rolling
direction (C-direction), and a magnetic flux density in L-direction
B.sub.50-L of the specimen is measured in the same manner as in the
above experiment to obtain results shown in FIG. 2. It can be seen
from FIG. 2 that the magnetic flux density in the rolling direction
can be increased by heating the cold rolled sheet containing not
less than 0.01 mass % of C at a temperature rising rate of not less
than 100.degree. C./sec to conduct finish annealing.
[0024] Although the above reason is not clear at the current
moment, it is considered that solute C content is increased by
making C content to not less than 0.01 mass %, which is easy to
form a deformation band in the cold rolling and develops Goss
structure after the annealing, and further that development of
(111) orientation is suppressed by conducting rapid heating and
hence a crystal structure of (110) orientation or (100) orientation
is developed in the rolling direction to improve the magnetic flux
density in the rolling direction. As seen from this result, it is
necessary that in order to increase the magnetic flux density in
the rolling direction, the temperature rising rate in the heating
for finish annealing is not less than 100.degree. C./sec and
further C content in the raw steel sheet is not less than 0.01 mass
% from a viewpoint of ensuring solute C before the finish
annealing.
[0025] This invention is made as a result of further consideration
to the above knowledge.
[0026] The reason on the limitation of the element composition in
the non-oriented electrical steel sheet of the invention will be
described below.
[0027] C: 0.01-0.1 mass %
[0028] C solid-soluted in steel pins dislocation introduced in the
cold rolling to easily form a deformation band. This deformation
band has an effect of improving magnetic property in the rolling
direction because Goss orientation {110}<001> is
preferentially grown by recrystallization in the finish annealing.
In order to obtain the effect of solute C, it is necessary that the
C content in the steel sheet before the cold rolling is not less
than 0.01 mass %. On the other hand, if solute C in a steel sheet
product is large, magnetic aging is caused to deteriorate magnetic
property, so that it is necessary that decarburization is conducted
at the annealing step after the cold rolling to reduce C content to
not more than 0.005 mass %. However, if C content in steel exceeds
0.1 mass %, there is a fear that the decarburization can not be
conducted sufficiently by the above decarburization annealing.
Therefore, the C content is a range of 0.01-0.1 mass %. Preferably,
it is a range of 0.015-0.05 mass %. A more preferable lower limit
is 0.02 mass %. Moreover, the decarburization annealing may be
conducted at any time after the rapid heating.
[0029] Si: not more than 4 mass %
[0030] Si is an element added for enhancing a specific resistance
of steel to improve a property on iron loss. In order to obtain
such an effect, it is preferable to be added in an amount of not
less than 1.0 mass %. On the other hand, the addition of more than
4 mass % hardens steel to make rolling difficult, so that the upper
limit is 4 mass %. Preferably, it is a range of 1.0-4.0 mass %. A
more preferable lower limit is 1.5 mass %.
[0031] Mn: 0.05-3 mass %
[0032] Mn is an element required for preventing cracking in the hot
rolling due to S. In order to obtain such an effect, the addition
of not less than 0.05 mass % is necessary. On the other hand, the
addition of more than 3 mass % brings about the increase of cost of
raw materials. Therefore, Mn is a range of 0.05-3 mass %. A more
preferable upper limit is 2.5 mass %. Moreover, since Mn rises a
specific resistance, if it is intended to proceed further iron
loss, it is preferable to be not less than 1.5 mass %, while if the
workability and productivity are important, it is preferable to be
not more than 2.0 mass %.
[0033] Al: not more than 3 mass %
[0034] Al has an effect of enhancing a specific resistance of steel
to improve a property on iron loss likewise Si, so that it is an
element added if necessary. However, the addition of more than 3
mass % deteriorates the rolling property, so that the upper limit
is 3 mass %. More preferably, it is not more than 2.5 mass %. Also,
Al is preferable to be not less than 1.0 mass % if the iron loss is
more important, and not more than 2.0 mass % if the workability and
productivity are more important. Moreover, the addition of Al is
not essential, but if Al is not added, it is usually present
slightly as an inevitable impurity.
[0035] S: not more than 0.005 mass %, N: not more than 0.005 mass
%
[0036] S and N are impurity elements inevitably incorporated into
steel. If each of them exceeds 0.005 mass %, the magnetic property
are deteriorated. In the invention, therefore, each of S and N is
limited to not more than 0.005 mass %.
[0037] The non-oriented magnet steel sheet according to the
invention may contain Sn and Sb within the following ranges in
addition to the above essential ingredients.
[0038] Sn: 0.005-0.1 mass %, Sb: 0.005-0.1 mass %
[0039] Sn and Sb are elements having an effect of not only
improving the texture after the finish annealing to increase the
magnetic flux density in the rolling direction but also preventing
oxidation or nitriding of surface layer in the steel sheet to
suppress the formation of fine grains in the surface layer of the
steel sheet and prevent the deterioration of the magnetic property.
In order to develop such an effect, at least one of Sn and Sb is
preferable to be added in an amount of not less than 0.005 mass %.
However, if the content of each of these elements exceeds 0.1 mass
%, the growth of crystal grains is inhibited and these is rather a
fear of deteriorating the magnetic property. Therefore, each of Sn
and Sb is preferable to be added within a range of 0.005-0.1 mass
%.
[0040] In the non-oriented electrical steel sheet according to the
invention, the remainder other than the above ingredients is Fe and
inevitable impurities. However, it is not refused that elements
other than the above ingredients are contained unless they do not
damage the effects of the invention and also that the
abovementioned optional ingredients are contained in an amount of
less than the above lower limit as an impurity.
[0041] The production method of the non-oriented electrical steel
sheet according to the invention will be described below.
[0042] The production method of the non-oriented electrical steel
sheet according to the invention is preferable to be a method
wherein steel having the aforementioned element composition
adaptable for the invention is melted by a usually well-known
refining process using a converter, an electric furnace, a vacuum
degassing apparatus or the like and shaped into a steel slab by a
continuous casting method or an ingot making-slabbing method and
thereafter the steel slab is hot rolled by a usually well-known
method, subjected to a hot band annealing if desired and cold
rolled to form a cold rolled sheet having a final thickness and
then the cold rolled sheet is subjected to finish annealing and
decarburization annealing and further to the formation of various
insulating coatings, if necessary, to provide a product. In this
production method, the process up to the cold rolling is not
particularly limited except that the element composition of the raw
materials is adapted to that of the invention, so that the usually
well-known production process can be adopted. Also, the hot band
annealing is not necessarily conducted at a higher temperature and
is sufficient at about 850-1000.degree. C., but the hot band
annealing outside the above range is not excluded.
[0043] The production method subsequent to the cold rolling will be
described below.
[0044] Cold rolling
[0045] The cold rolling may be a single cold rolling or may be two
or more cold rollings through an intermediate annealing. Moreover,
if the rolling reduction in the production of the non-oriented
electrical steel sheet is usual (not less than about 50%), the
introduction of the deformation band is ensured by the
aforementioned element composition.
[0046] Finish Annealing
[0047] The finish annealing is necessary to be conducted by heating
from 300.degree. C. to 800.degree. C. at a temperature rising rate
of not less than 100.degree. C./sec. Because, the texture of (111)
orientation undesirable to the magnetic property is developed at a
temperature rising rate of less than 100.degree. C./sec.
Preferably, it is not less than 200.degree. C./sec. The upper limit
is not particularly defined, but is practical to be not more than
about 500.degree. C./sec.
[0048] Also, the soaking temperature is necessary to be a range of
750-1100.degree. C. The lower limit temperature may be a
temperature above a recrystallization temperature, but is necessary
to be not lower than 750.degree. C. for causing the sufficient
recrystallization in the continuous annealing. While, if the
soaking temperature exceeds 1100.degree. C., the recrystallized
grains become coarsened or the burden of the annealing furnace
becomes larger. Preferably, it is a range of 800-1050.degree.
C.
[0049] Also, the soaking time may be a time of sufficiently
proceeding the recrystallization, and may be, for example, not less
than 5 seconds. While, if it exceeds 120 seconds, the effect is
saturated, so that it is preferable to be not more than 120
seconds.
[0050] Moreover, the cooling condition after the annealing is
sufficient to be usual conditions, and is not particularly limited.
Also, the method of making the temperature rising rate in the
heating for finish annealing to not less than 100.degree. C./sec is
not particularly limited, and a direct power heating method, a
dielectric heating method or the like may be used preferably.
[0051] Decarburization annealing
[0052] The finish-annealed steel sheet is subjected to
decarburization annealing to reduce solute C content and prevent
magnetic aging, so that it is preferable to reduce C content in
steel to not more than 0.0050 mass %. If the C content exceeds
0.0050 mass %, it is feared to cause magnetic aging of a steel
sheet product. The conditions of the decarburization annealing may
be commonly well-known conditions. For example, it can be conducted
under conditions of 800-850.degree. C..times.10-30 seconds in an
oxidizing atmosphere having a dew point of not lower than
30.degree. C.
[0053] Moreover, the decarburization annealing may be conducted
continuously followed by the finish annealing, or may be separately
conducted in another line. The steel sheet after the
decarburization annealing is preferable to be rendered into a
product by subsequently forming various insulating coatings, if
desired.
EXAMPLES
[0054] Each of steels Nos. 1-29 having an element composition shown
in Table 1 is melted by a usually well-known refining process and
continuously cast into a raw steel material (slab), and the slab is
heated at 1080.degree. C. for 30 minutes and then hot rolled to
form a hot rolled sheet having a thickness of 2.4 mm Then, the hot
rolled sheet is subjected to an annealing at 900.degree. C. for 30
seconds and to a single cold rolling to form a cold rolled sheet
having a final thickness of 0.35 mm. Thereafter, the cold rolled
sheet is heated at various temperature rising rates of not less
than 30.degree. C./sec in a direct power heating furnace and soaked
at a temperature shown in Table 1 for 10 seconds to conduct finish
annealing, and then subjected to decarburization annealing of
850.degree. C..times.30 seconds (dew point: 30.degree. C.) to
prepare a non-oriented electrical steel sheet.
[0055] Next, a L-direction test specimen of L: 180 mm.times.C: 30
mm is cut out from each of the thus obtained non-oriented
electrical steel sheets, which is subjected to a single sheet test
to measure a magnetic flux density in L direction B.sub.50
(magnetic flux density as magnetized at 5000 A/m). The measured
results are also shown in Table 1. It can be seen from the results
of Table 1 that all of steel sheets obtained by subjecting steel
sheet adapted to the element composition of the invention to finish
annealing under conditions adapted to the invention have a high
magnetic flux density because B.sub.50 in L direction (B.sub.50-L)
is not less than 1.75 T.
TABLE-US-00001 TABLE 1 Finish annealing conditions Chemical
composition (mass %) Temperature rising rate Annealing temperature
B.sub.50-L No. C Si Mn Al S N Sn Sb (.degree. C./sec) (.degree. C.)
(T) Remarks 1 0.003 3.0 0.15 0.001 0.0012 0.0016 0.001 0.001 150
950 1.72 Comparative Example 2 0.005 3.0 0.15 0.001 0.0013 0.0020
0.001 0.001 150 950 1.73 Comparative Example 3 0.010 3.0 0.10 0.001
0.0010 0.0018 0.001 0.001 200 950 1.78 Invention Example 4 0.020
3.0 0.15 0.001 0.0014 0.0015 0.001 0.001 200 950 1.79 Invention
Example 5 0.050 0.5 0.15 0.001 0.0012 0.0017 0.001 0.001 300 800
1.88 Invention Example 6 0.100 1.5 0.15 0.001 0.0014 0.0015 0.001
0.001 300 850 1.84 Invention Example 7 0.030 3.7 0.15 0.001 0.0018
0.0015 0.001 0.001 300 1025 1.76 Invention Example 8 0.020 4.5 0.15
0.001 0.0014 0.0015 0.001 0.001 Breakage during cold rolling
Comparative Example 9 0.020 3.0 0.15 0.020 0.0014 0.0015 0.001
0.001 120 950 1.78 Invention Example 10 0.020 3.0 0.15 0.10 0.0014
0.0015 0.001 0.001 120 1000 1.77 Invention Example 11 0.070 2.5
0.15 0.50 0.0014 0.0015 0.001 0.001 150 950 1.77 Invention Example
12 0.020 2.0 0.15 1.20 0.0014 0.0015 0.001 0.001 150 950 1.77
Invention Example 13 0.040 1.8 0.15 2.50 0.0014 0.0015 0.001 0.001
200 900 1.77 Invention Example 14 0.020 1.0 0.10 4.50 0.0015 0.0021
0.001 0.001 Breakage during cold rolling Comparative Example 15
0.020 3.0 0.07 0.001 0.0014 0.0015 0.001 0.001 250 900 1.80
Invention Example 16 0.015 2.5 1.00 0.001 0.0016 0.0015 0.001 0.001
250 900 1.78 Invention Example 17 0.020 2.0 2.50 0.001 0.0014
0.0017 0.001 0.001 250 900 1.77 Invention Example 18 0.020 3.0 4.00
0.001 0.0014 0.0015 0.001 0.001 300 900 1.73 Comparative Example 19
0.020 3.0 0.15 0.001 0.0090 0.0015 0.001 0.001 300 1000 1.70
Comparative Example 20 0.020 3.0 0.15 0.001 0.0014 0.0080 0.001
0.001 300 1000 1.71 Comparative Example 21 0.060 3.0 0.15 0.001
0.0014 0.0015 0.050 0.001 350 1030 1.80 Invention Example 22 0.030
3.0 0.15 0.001 0.0014 0.0015 0.001 0.050 350 1030 1.80 Invention
Example 23 0.020 3.0 0.07 0.001 0.0014 0.0015 0.030 0.030 350 1000
1.79 Invention Example 24 0.020 3.0 0.15 0.001 0.0014 0.0015 0.008
0.001 250 1000 1.78 Invention Example 25 0.020 3.0 0.15 0.001
0.0014 0.0015 0.001 0.008 250 1000 1.78 Invention Example 26 0.030
3.0 0.16 0.001 0.0017 0.0014 0.001 0.001 30 950 1.71 Comparative
Example 27 0.030 3.0 0.16 0.001 0.0013 0.0024 0.001 0.001 80 950
1.71 Comparative Example 28 0.020 3.0 0.15 0.001 0.0014 0.0015
0.050 0.001 250 1000 1.78 Invention Example 29 0.020 3.0 0.15 0.001
0.0014 0.0015 0.001 0.050 250 1000 1.78 Invention Example
INDUSTRIAL APPLICABILITY
[0056] According to the invention, there can be provided
non-oriented electrical steel sheets having excellent magnetic
property in the rolling direction of the steel sheet. Therefore,
the invention largely contributes to improve the efficiency of
motor or transformer by applying the steel sheet to applications
requiring excellent magnetic property in the rolling direction such
as segment core, core for transformer and the like.
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