JP2017128801A - Non-oriented electromagnetic steel sheet and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-oriented electromagnetic steel sheet having excellent magnetic flux density while avoiding cost increase.SOLUTION: A non-oriented electromagnetic steel sheet has a component composition comprising, in mass%, C: 0.0050% or less, Si: 6.00% or less, Mn: 0.050% or more and 3.00% or less, P: 0.100% or less, S: 0.0050% or less, N: 0.0050% or less, Al: 0.0050% or less and B: 0.00030% or less, and further comprising, in mass%, Sn: 0.05% or more and 0.50% or less and/or Sb: 0.05% or more and 0.50% or less, with the balance being Fe and unavoidable impurities.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-oriented electrical steel sheet and a method for producing the same.

  A non-oriented electrical steel sheet is a kind of soft magnetic material widely used as a core material for motors and the like. In recent years, electric vehicles and hybrid vehicles have been put into practical use, motor drive systems have been developed, and the motor drive frequency tends to increase year by year. At present, the fundamental frequency is generally several hundred to several kHz, and the core loss characteristic of the iron core in a high frequency range is regarded as important. Therefore, conventionally, an iron loss in a high frequency region has been reduced by adding an alloy element such as Si or Al or by reducing a plate thickness.

  However, when the above alloy elements are added, a decrease in magnetic flux density is inevitable. In order to reduce the plate thickness, it is necessary to increase the cold rolling reduction ratio. When the cold rolling reduction ratio is increased, the primary recrystallization texture is accumulated in the {111} direction which is the stable rolling direction, leading to a decrease in magnetic flux density. A decrease in magnetic flux density increases the copper loss of the motor, leading to a decrease in motor efficiency. Therefore, not only a reduction in iron loss in a high frequency region but also an improvement in magnetic flux density is desired at the same time.

  As a method for producing a non-oriented electrical steel sheet having an excellent magnetic flux density, Patent Document 1 describes that 0.1 to 5% by mass of Co is added to steel having 4% by mass or less of Si. However, since Co is very expensive, there is a problem that the manufacturing cost is remarkably increased. Patent Document 2 proposes a method of controlling Al to 0.017 mass% or less, N to 0.0030 mass% or less, and controlling the particle size of the hot-rolled annealed sheet. However, this method requires warm rolling with a plate temperature of about 200 ° C, and the cost increases in order to accommodate the equipment or process management due to production constraints. It becomes a problem.

JP 2000-129410 A JP 2001-316729

  This invention is made | formed in view of such a situation, and it aims at providing the non-oriented electrical steel plate excellent in magnetic flux density, avoiding the increase in cost.

  In order to solve the above-mentioned problems, the inventors made extensive studies focusing on the segregation elements Sn and Sb effective in improving the texture. As a result, it has been found that a steel in which Al is reduced to a very small amount and a large amount of Sn or Sb is added greatly improves the magnetic flux density by reducing B or As, and the effect is large in the cold rolling reduction ratio. As a result, the inventors have further found that it is remarkable, and have come to discover the present invention anew.

Hereinafter, experiments that led to the present invention will be described.
(Experiment 1)
In order to develop a non-oriented electrical steel sheet having excellent magnetic flux density, the inventors have refocused on Sn and Sb, which are effective for improving the texture, and investigated the influence of Al on the magnetic flux density improvement effect of Sn.

C: 0.0020 mass%, Si: 2.70 mass%, Mn: 0.200 mass%, P: 0.020 mass%, S: 0.0020 mass%, Al: 0.3 mass%, N: 0.0020 mass%, As: 0.0020 mass%, and B : Al addition steel containing 0.00010 mass%, C: 0.0020 mass%, Si: 3.00 mass%, Mn: 0.200 mass%, P: 0.020 mass%, S: 0.0020 mass%, Al: 0.001 mass%, N: Based on two types of steel containing 0.0020% by mass, As: 0.0020% by mass, and B: 0.00010% by mass without addition of Al, Sn was added in a range of 0% to 0.26%. A steel ingot was used as a test material. These specimens were hot-rolled into hot-rolled sheets with a thickness of 2.0 mm, and then subjected to hot-rolled sheet annealing at 1000 ° C. for 30 seconds, and then cold-rolled at a reduction rate of 82.5% A 0.35 mm cold-rolled sheet was used. Then, finish annealing was performed at 1000 ° C. for 10 seconds in an atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0005 (10% H ₂ -90% N ₂ atmosphere, dew point -50 ° C.), and the magnetic flux density B _{50 of the} steel plate Was measured with a 25 cm Epstein apparatus.

The relationship between the magnetic flux density B ₅₀ and the Sn amount is shown in FIG. Although the same result as the conventional knowledge that the magnetic flux density B ₅₀ increases when the Sn content increases regardless of whether Al is added or not is obtained, the steel with no Al added has a magnetic flux of Sn content 0.05% or more. It was found that the density was greatly improved. The reason why the increase in magnetic flux density B ₅₀ is different between steel without Al and steel added with Al is not yet clear at present, but steel without Al promotes grain boundary segregation of Sn. It is estimated that

(Experiment 2)
Furthermore, the inventors investigated the influence of the rolling reduction on the effect of improving the magnetic flux density of Sn.
C: 0.0020 mass%, Si: 2.70 mass%, Mn: 0.200 mass%, P: 0.020 mass%, S: 0.0020 mass%, Al: 0.3 mass%, N: 0.0020 mass%, As: 0.0020 mass%, and B : In addition to 0.00010 mass%, Sn: 0.15 mass% or Al added steel containing 0.001 mass%, C: 0.0025 mass%, Si: 3.00 mass%, Mn: 0.200 mass%, P: 0.020 mass%, S : In addition to 0.0020 mass%, Al: 0.001 mass%, N: 0.0020 mass%, As: 0.0020 mass%, and B: 0.00010 mass%, add Al containing Sn: 0.15 mass% or 0.001 mass% Steel ingots with no steel were used as test materials, and these were hot-rolled to a thickness of 2.0 mm, and then subjected to hot-rolled sheet annealing at 1000 ° C. for 30 seconds.

Thereafter, cold rolling is performed at a rolling reduction of 80 to 95% to obtain a cold rolled sheet having a thickness of 0.40 to 0.10 mm. Thereafter, an atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0005 (10% H ₂ -90 Finish annealing was performed at 1000 ° C. for 10 seconds in a% N ₂ atmosphere with a dew point of −50 ° C., and the magnetic flux density B _{50 of the} steel sheet was measured with a 25 cm Epstein apparatus.

The relationship between the magnetic flux density B ₅₀ and the rolling reduction is shown in FIG. The steel added with Al does not change the increase rate of the magnetic flux density B ₅₀ value due to Sn addition even when the rolling reduction increases, but the steel without Al added from 85% reduction rate to the magnetic flux density B ₅₀ value due to Sn addition. It has been found that the rate of increase of becomes higher. That is, it can be seen that when Sn is added to steel to which Al is not added, the rolling reduction can be increased without reducing the magnetic flux density, in other words, the plate thickness can be reduced. The reason why the rate of increase in the magnetic flux density B ₅₀ value when the reduction ratio is high is different between the steel not added with Al and the steel added with Al is not yet clarified at this time. It is presumed that the (111) -oriented grain reduction effect due to Sn increased due to the effect of the steel not added with Al.

(Experiment 3)
Next, the inventors investigated the influence of a small amount of B on the effect of improving the magnetic flux density by Sn.
C: 0.0020 mass%, Si: 3.00 mass%, Mn: 0.200 mass%, P: 0.020 mass%, S: 0.0020 mass%, Al: 0.001 mass%, N: 0.0020 mass%, As: 0.0020 mass%, and Sn A steel ingot containing 0.15% by mass and variously added B in the range of 0.00002 to 0.00126% by mass was used as a test material, and these were hot-rolled to a plate thickness of 2.0 mm. Then, hot-rolled sheet annealing at 1000 ° C. for 30 seconds was performed. Then, reduction ratio 82.5%, or by cold rolling at 90.0%, to get the cold-rolled sheet in each thickness 0.35mm or 0.20 mm, then, the atmosphere oxygen potential PH ₂ O / PH ₂ is 0.0005 (10 Finish annealing was performed at 1000 ° C. for 10 seconds in a% H ₂ -90% N ₂ atmosphere, dew point −50 ° C., and the magnetic flux density B _{50 of the} steel sheet was measured with a 25 cm Epstein apparatus.

The relationship between the magnetic flux density B ₅₀ and B amount and cold rolling reduction rate shown in FIG. It can be seen that when the B content exceeds 0.00030 mass%, the magnetic flux density decreases. The reason why the effect of Sn is suppressed by an increase in the amount of B is not clear at this time, but it is considered that the segregation of Sn grain boundaries was suppressed by segregating B at the grain boundaries.
Since the above results were confirmed even when the As content was more than 0.0050 mass%, it is also important to reduce the As amount in order to obtain the Sn effect.

(Experiment 4)
Next, the adhesiveness of the insulating film after strain relief annealing was investigated for the steel with reduced Al and the magnetic flux density improved by the addition of Sn.
C: 0.0020 mass%, Si: 3.00 mass%, Mn: 0.200 mass%, P: 0.020 mass%, S: 0.0020 mass%, Al: 0.0010 mass%, N: 0.0020 mass%, Sn: 0.10 mass%, B: A steel ingot containing 0.00010% by mass is used as a test material, hot rolled into a hot rolled sheet having a thickness of 2.0 mm, and then subjected to hot rolled sheet annealing at 1000 ° C. for 30 seconds, followed by a rolling reduction of 82.5%. Was cold-rolled to obtain a cold-rolled sheet having a thickness of 0.35 mm. Thereafter, finish annealing was performed at 1000 ° C. for 10 seconds in an atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0005 (10% H ₂ -90% N ₂ atmosphere, dew point −50 ° C.).

At that time, cooling at 700 to 500 ° C. was performed in an atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0001 to 0.005. Thereafter, an insulating coating was applied to the steel plate, and 750 ° C. × 2 hours of strain relief annealing was performed in a 100 vol% N ₂ atmosphere, and the coating adhesion of the obtained steel plate was investigated. Adhesion was evaluated by the peeled area (%) of the coating after the adhesive tape was peeled off at the bent portion after bending 90 ° with 50 mmφ. The conditions such as the material of the adhesive tape and the tape peeling speed were in accordance with JIS Z 0237.

  FIG. 4 shows the relationship between the oxygen potential during cooling and the film adhesion. It can be seen that when the oxygen potential is less than 0.001, the film adhesion sharply decreases. That is, good film adhesion with an oxygen potential of 0.001 or more and a film peeling area of 10% or less can be obtained. The reason why the film adhesion varies depending on the oxygen potential at the time of finish annealing cooling is not clear at present, but the following may be considered. The cause of film peeling is thought to be the segregation of Sn at the interface between the film and the base iron by strain relief annealing, and the formation of an oxide layer on the steel sheet surface layer by finish annealing suppressed the segregation of Sn at the interface. it is conceivable that.

  The effect of improving the magnetic flux density as described above was the same even when Sb was added instead of Sn. From these results, steel with a very small amount of Al and a large amount of Sn or Sb greatly improves the magnetic flux density by reducing B or As, and the effect is large in cold rolling reduction. It turned out that it was so remarkable. However, if a large amount of Sn or Sb is added, the film adhesion after strain relief annealing becomes a problem. Therefore, in order to utilize strain relief annealing, it is preferable to adjust the oxygen potential by cooling the finish annealing.

  The present invention has been made based on the above-described novel findings and has the following configuration.

1. % By mass
C: 0.0050% or less,
Si: 6.00% or less,
Mn: 0.050% to 3.00%,
P: 0.100% or less,
S: 0.0050% or less,
N: 0.0050% or less,
Al: 0.0050% or less and B: 0.00030% or less,
A non-oriented electrical steel sheet characterized by containing Sn: 0.05% or more and 0.50% or less and / or Sb: 0.05% or more and 0.50% or less, with the balance having a component composition consisting of Fe and inevitable impurities.

2. The component composition further includes:
% By mass
The non-oriented electrical steel sheet according to 1 above, containing As: 0.0050% or less.

3. The component composition further includes:
% By mass
Ca: 0.0001% or more and 0.0300% or less,
REM: 0.0001% to 0.0300% and
The non-oriented electrical steel sheet according to 1 or 2 above, which contains one or more selected from Mg: 0.0001% to 0.0300%.

4). % By mass
C: 0.0050% or less,
Si: 6.00% or less,
Mn: 0.050% to 3.00%,
P: 0.100% or less,
S: 0.0050% or less,
N: 0.0050% or less,
Al: 0.0050% or less and B: 0.00030% or less,
A steel slab containing Sn: 0.05% or more and 0.50% or less and / or Sb: 0.05% or more and 0.50% or less, with the balance being composed of Fe and inevitable impurities, hot-rolled into a hot-rolled steel sheet,
Pickling the hot-rolled steel sheet;
The hot-rolled steel sheet subjected to pickling is cold-rolled steel sheet by subjecting the hot-rolled steel sheet to cold rolling twice or more sandwiching one or intermediate annealing,
A method for producing a non-oriented electrical steel sheet that is coated after the cold-rolled steel sheet is subjected to finish annealing,
A method for producing a non-oriented electrical steel sheet, wherein the rolling reduction in cold rolling immediately before the finish annealing is 85% or more.

5. % By mass
C: 0.0050% or less,
Si: 6.00% or less,
Mn: 0.050% to 3.00%,
P: 0.100% or less,
S: 0.0050% or less,
N: 0.0050% or less,
Al: 0.0050% or less and B: 0.00030% or less,
A steel slab containing Sn: 0.05% or more and 0.50% or less and / or Sb: 0.05% or more and 0.50% or less, with the balance being composed of Fe and inevitable impurities, hot-rolled into a hot-rolled steel sheet,
Pickling the hot-rolled steel sheet;
The hot-rolled steel sheet subjected to pickling is cold-rolled steel sheet by subjecting the hot-rolled steel sheet to cold rolling twice or more sandwiching one or intermediate annealing,
A method for producing a non-oriented electrical steel sheet that is coated after the cold-rolled steel sheet is subjected to finish annealing,
The finish annealing is performed by cooling from 700 ° C. to 500 ° C. over 1 to 300 seconds in an oxidizing atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0010 or more. A method of manufacturing a steel sheet.

6). % By mass
C: 0.0050% or less,
Si: 6.00% or less,
Mn: 0.050% to 3.00%,
P: 0.100% or less,
S: 0.0050% or less,
N: 0.0050% or less,
Al: 0.0050% or less and B: 0.00030% or less,
A steel slab containing Sn: 0.05% or more and 0.50% or less and / or Sb: 0.05% or more and 0.50% or less, with the balance being composed of Fe and inevitable impurities, hot-rolled into a hot-rolled steel sheet,
Pickling the hot-rolled steel sheet;
The hot-rolled steel sheet subjected to pickling is cold-rolled steel sheet by subjecting the hot-rolled steel sheet to cold rolling twice or more sandwiching one or intermediate annealing,
A method for producing a non-oriented electrical steel sheet that is coated after the cold-rolled steel sheet is subjected to finish annealing,
The rolling reduction in cold rolling immediately before the finish annealing is 85% or more,
The finish annealing is performed by cooling from 700 ° C. to 500 ° C. over 1 to 300 seconds in an oxidizing atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0010 or more. A method of manufacturing a steel sheet.

7). The component composition further includes:
% By mass
The method for producing a non-oriented electrical steel sheet according to any one of 4 to 6 above, comprising As: 0.0050% or less.

8). The component composition further includes:
% By mass
Ca: 0.0001% or more and 0.0300% or less,
REM: 0.0001% to 0.0300% and
Mg: One or more selected from 0.0001% or more and 0.0300% or less is contained, The method for producing a non-oriented electrical steel sheet according to any one of 4 to 7 above.

  ADVANTAGE OF THE INVENTION According to this invention, the non-oriented electrical steel plate excellent in magnetic flux density can be provided, avoiding the increase in cost.

Is a diagram showing the relationship between the magnetic flux density B ₅₀ of Sn content and the finish annealed sheet. It is a diagram showing the relationship between the magnetic flux density B ₅₀ of annealed sheet finishing the cold rolling reduction rate. It is a diagram showing the relationship between the magnetic flux density B ₅₀ of B amount and cold rolling reduction ratio and finish annealed sheet. It is a diagram showing the relationship between the peeling area of finish annealing cooling during coating of oxygen potential PH ₂ O / PH ₂ and stress relief annealing plate.

  Hereinafter, a non-oriented electrical steel sheet according to an embodiment of the present invention will be described. First, the reasons for limiting the component composition of steel will be described. In the present specification, “%” representing the content of each component element means “% by mass” unless otherwise specified.

C: 0.0050% or less C is limited to 0.0050% or less because it causes magnetic aging in the product plate. Preferably, it is 0.0040% or less.

Si: 6.00% or less
Si is an element that increases the specific resistance of steel and is effective in reducing iron loss. If over 6.00% is added, it becomes extremely brittle and cold rolling becomes difficult, so the upper limit is made 6.00%. Preferably it is 1.00% or more and 5.00% or less of range.

Mn: 0.050% to 3.00%
Since Mn is an element effective for preventing red hot brittleness during hot rolling, it needs to be contained by 0.050% or more. However, if it exceeds 3.00%, the cold rolling property is lowered or the magnetic flux density is lowered, so the upper limit is made 3.00%. Preferably it is 0.100% or more and 2.00% or less of range.

P: 0.100% or less P is an element effective for adjusting the hardness and improving the punching workability because of its excellent solid solution strengthening ability. If it exceeds 0.100%, embrittlement becomes significant, so the upper limit is made 0.100%. Preferably it is 0.050% or less.

S: 0.0050% or less Since S is a harmful element that generates sulfides and increases iron loss, the upper limit is made 0.0050%. Preferably it is 0.0040% or less.

N: 0.0050% or less Since N is a harmful element that generates nitrides and increases iron loss, the upper limit is made 0.0050%. Preferably it is 0.0040% or less.

Al: 0.0050% or less
Al is one of the important elements in the present invention. If the content exceeds 0.0050%, the effect of improving the magnetic flux density by adding Sn or Sb described above cannot be obtained, so the upper limit is made 0.0050%. Preferably it is 0.0030% or less.

B: 0.00030% or less B is one of the important elements in the present invention. If the content exceeds 0.00030%, the effect of improving the magnetic flux density by adding Sn or Sb described above cannot be obtained, so the upper limit is made 0.00030%. Preferably it is 0.00010% or less.

Sn: 0.05% to 0.50% and / or Sb: 0.05% to 0.50%
Sn and Sb are one of the important elements in the present invention. In order to obtain the effect of improving the magnetic flux density according to the present invention, it is necessary to contain 0.05% or more. However, if it exceeds 0.50%, embrittlement becomes significant, so the upper limit is made 0.50%. Preferably they are 0.05% or more and 0.20% or less.

  The basic components of the present invention have been described above. The balance other than the above components is Fe and inevitable impurities, but in addition, the following elements can be appropriately contained as required.

As: 0.0050% or less
When As is contained in excess of 0.0050%, the effect of improving the magnetic flux density by adding Sn or Sb described above cannot be obtained, so the upper limit is made 0.0050%. Preferably it is 0.0030% or less.

Ca: 0.0001% or more and 0.0300% or less, REM: 0.0001% or more and 0.0300% or less, and Mg: 0.0001% or more and 0.0300% or less
Ca, REM, and Mg are elements that are effective in reducing iron loss because they all fix S and suppress fine precipitation of sulfides. In order to acquire this effect, it is necessary to add 0.0001% or more of each. However, even if added over 0.0300%, the above effect is saturated. Therefore, when adding 1 type, or 2 or more types chosen from Ca, REM, and Mg, it is set as 0.0001% or more and 0.0300% or less of each, respectively.

Next, the manufacturing conditions of the grain-oriented electrical steel sheet according to the present invention will be described.
The non-oriented electrical steel sheet of the present invention is a known non-oriented electrical steel sheet manufacturing method as long as the steel material used for the production thereof has a content of Al, Sn, Sb and B within the above-mentioned range. Can be used. For example, the following method, that is, the steel adjusted to the above-mentioned predetermined component composition in a refining process such as a converter or an electric furnace is melted, subjected to secondary refining with a degassing facility, etc., and continuously cast into a steel slab. Then, after hot rolling and hot-rolled sheet annealing as necessary, pickling, cold rolling, finish annealing, and strain relief annealing can be employed.
However, as described later, it is preferable to adjust the rolling reduction in cold rolling immediately before finish annealing to reduce the plate thickness, and to adjust the oxygen potential of the cooling atmosphere of finish annealing to improve film adhesion. preferable.

  Here, it is preferable that the plate | board thickness of the steel plate (hot-rolled plate) after the said hot rolling shall be 1.0-5.0 mm. If the thickness is less than 1.0 mm, hot rolling trouble increases. On the other hand, if the thickness exceeds 5.0 mm, the cold rolling reduction becomes too high and the texture deteriorates.

Moreover, hot-rolled sheet annealing can be performed as needed. When hot-rolled sheet annealing is performed, the soaking temperature is preferably in the range of 900 to 1200 ° C. If the temperature is lower than 900 ° C, the effect of hot-rolled sheet annealing cannot be sufficiently obtained, so the magnetic properties are not improved. On the other hand, if the temperature exceeds 1200 ° C, it is disadvantageous in terms of cost, and scale-induced surface defects are caused. This is because it occurs. The soaking time is preferably 1 to 300 seconds. If it is less than 1 sec, the effect of hot-rolled sheet annealing cannot be sufficiently obtained, and the effect is saturated even if it exceeds 300 sec.
When hot-rolled sheet annealing is not performed, self-annealing can also be performed. Self-annealing is annealing by the heat | fever hold | maintained inside the hot rolling coil after hot rolling.

Further, the cold rolling applied to the hot-rolled sheet or the hot-rolled annealed sheet is preferably performed once or twice or more with the intermediate annealing interposed therebetween. In particular, with regard to the final cold rolling, the effect of improving the magnetic flux density is increased by performing warm rolling in which the plate temperature is rolled at a temperature of about 200 ° C. Therefore, warm rolling is preferable if there is no problem in terms of cost due to equipment and production constraints.
Moreover, it is preferable that the rolling reduction in the cold rolling immediately before the finish annealing is 85% or more.

  The plate thickness (final plate thickness) of the cold-rolled plate is preferably in the range of 0.1 to 1.0 mm. This is because if the thickness is less than 0.1 mm, the productivity decreases, while if it exceeds 1.0 mm, the effect of reducing the iron loss is small. In particular, in the present invention, since the plate thickness can be reduced without reducing the magnetic flux density, the final plate thickness is preferably set to 0.3 mm or less.

  The finish annealing applied to the cold-rolled sheet having the final thickness is preferably soaked at a temperature of 700 to 1200 ° C. for 1 to 300 seconds in a continuous annealing furnace. If the soaking temperature is less than 700 ° C., recrystallization does not proceed sufficiently and it is difficult to obtain good magnetic properties, and the effect of correcting the plate shape in continuous annealing cannot be sufficiently obtained. On the other hand, when the temperature exceeds 1200 ° C., the crystal grains become coarse and the toughness decreases.

  The steel sheet after the finish annealing is preferably formed with an insulating coating on the steel sheet surface in order to increase the inter-layer resistance and reduce the iron loss. In particular, when it is desired to ensure good punchability, it is desirable to apply a semi-organic insulating film containing a resin.

The non-oriented electrical steel sheet with the insulating coating formed thereon may be used after further strain relief annealing, or may be used as it is without being subjected to strain relief annealing. Further, after the punching process, strain relief annealing may be performed. However, when used after applying strain relief annealing, the film adhesion becomes a problem, so cooling at 700-500 ° C in the above-mentioned finish annealing process takes 1-300 seconds in an atmosphere with an oxygen potential of 0.0010 or more. It is preferable to carry out. When the cooling time is less than 1 second, the oxidation of the steel sheet surface layer is not sufficiently promoted. On the other hand, when the cooling time exceeds 300 seconds, the productivity is lowered. When PH ₂ O / PH ₂ exceeds 5, an uneven oxidation called a gas mark occurs on the surface of the steel sheet, and the appearance as a product is impaired, so the upper limit is preferably about 5. The strain relief annealing is generally performed at 750 ° C. for about 2 hours.

Example 1
In the refining process of the converter-vacuum degassing treatment, No. 1 having the component composition shown in Table 1. 1 to 48 steel was melted and made into a slab by a continuous casting method, and then the slab was heated at 1140 ° C. for 1 hour and hot rolled to a thickness of 2.0 mm. Subsequently, the hot rolled sheet was subjected to hot rolled sheet annealing at 1000 ° C. for 30 seconds. Thereafter, the steel sheet was pickled and cold rolled at the rolling reduction shown in Table 1. Thereafter, finish annealing was performed at 1000 ° C. for 10 seconds in an atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0005 (10% H ₂ -90% N ₂ atmosphere, dew point −50 ° C.). At that time, cooling at 700 to 500 ° C. was performed under the conditions shown in Table 1, and an insulating coating was applied to the steel sheet to obtain a non-oriented electrical steel sheet. Thereafter, strain relief annealing was performed at 750 ° C. for 2 hours in a 100 vol% N ₂ atmosphere.

The iron loss W _15/50 and the magnetic flux density B ₅₀ of the finished annealed plate obtained as described above were measured, and the adhesion of the obtained strain relief annealed plate was investigated. Magnetic properties were evaluated by taking a 30mm x 280mm Epstein test piece and evaluated with a 25cm Epstein device. Adhesion was 90mm bend at 50mmφ, and the peeled area (% ). The conditions such as the material of the adhesive tape and the tape peeling speed were in accordance with JIS Z 0237. The results are also shown in Table 1.

(Example 2)
In the refining process of converter-vacuum degassing treatment, No. 1 having the component composition shown in Table 2 After melting steel of 49-67 and making it into a slab by a continuous casting method, the slab was heated at 1140 ° C. for 1 hour and hot rolled to a plate thickness of 2.0 mm. Subsequently, the hot-rolled sheet was subjected to a winding process corresponding to self-annealing at 650 ° C. for 1 hour. Thereafter, the steel sheet was pickled and cold rolled at the rolling reduction shown in Table 2. Thereafter, finish annealing was performed at 1000 ° C. for 10 seconds in an atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0005 (10% H ₂ -90% N ₂ atmosphere, dew point −50 ° C.). At that time, cooling at 700 to 500 ° C. was performed under the conditions shown in Table 2, and an insulating coating was applied to the steel sheet to obtain a non-oriented electrical steel sheet. Thereafter, strain relief annealing was performed at 750 ° C. for 2 hours in a 100 vol% N ₂ atmosphere.

The iron loss W _15/50 and the magnetic flux density B ₅₀ of the finished annealed plate obtained as described above were measured, and the adhesion of the obtained strain relief annealed plate was investigated. Magnetic properties were evaluated by taking a 30mm x 280mm Epstein test piece and evaluated with a 25cm Epstein device. Adhesion was 90mm bend at 50mmφ, and the peeled area (% ). The conditions such as the material of the adhesive tape and the tape peeling speed were in accordance with JIS Z 0237. The results are also shown in Table 2.

  From Table 1 and Table 2, by controlling the component composition of the steel material and the cold rolling reduction ratio within the range of the present invention, it is possible to avoid a significant cost increase and obtain a non-oriented electrical steel sheet having excellent magnetic properties. Recognize.

Claims (8)

% By mass
C: 0.0050% or less,
Si: 6.00% or less,
Mn: 0.050% to 3.00%,
P: 0.100% or less,
S: 0.0050% or less,
N: 0.0050% or less,
Al: 0.0050% or less and B: 0.00030% or less,
A non-oriented electrical steel sheet characterized by containing Sn: 0.05% or more and 0.50% or less and / or Sb: 0.05% or more and 0.50% or less, with the balance having a component composition consisting of Fe and inevitable impurities. The component composition further includes:
% By mass
2. The non-oriented electrical steel sheet according to claim 1, comprising As: 0.0050% or less. The component composition further includes:
% By mass
Ca: 0.0001% or more and 0.0300% or less,
REM: 0.0001% to 0.0300% and
The non-oriented electrical steel sheet according to claim 1 or 2, characterized by containing one or more selected from Mg: 0.0001% or more and 0.0300% or less. % By mass
C: 0.0050% or less,
Si: 6.00% or less,
Mn: 0.050% to 3.00%,
P: 0.100% or less,
S: 0.0050% or less,
N: 0.0050% or less,
Al: 0.0050% or less and B: 0.00030% or less,
A steel slab containing Sn: 0.05% or more and 0.50% or less and / or Sb: 0.05% or more and 0.50% or less, with the balance being composed of Fe and inevitable impurities, hot-rolled into a hot-rolled steel sheet,
Pickling the hot-rolled steel sheet;
The hot-rolled steel sheet subjected to pickling is cold-rolled steel sheet by subjecting the hot-rolled steel sheet to cold rolling twice or more sandwiching one or intermediate annealing,
A method for producing a non-oriented electrical steel sheet that is coated after the cold-rolled steel sheet is subjected to finish annealing,
A method for producing a non-oriented electrical steel sheet, wherein the rolling reduction in cold rolling immediately before the finish annealing is 85% or more. % By mass
C: 0.0050% or less,
Si: 6.00% or less,
Mn: 0.050% to 3.00%,
P: 0.100% or less,
S: 0.0050% or less,
N: 0.0050% or less,
Al: 0.0050% or less and B: 0.00030% or less,
A steel slab containing Sn: 0.05% or more and 0.50% or less and / or Sb: 0.05% or more and 0.50% or less, with the balance being composed of Fe and inevitable impurities, hot-rolled into a hot-rolled steel sheet,
Pickling the hot-rolled steel sheet;
The hot-rolled steel sheet subjected to pickling is cold-rolled steel sheet by subjecting the hot-rolled steel sheet to cold rolling twice or more sandwiching one or intermediate annealing,
A method for producing a non-oriented electrical steel sheet that is coated after the cold-rolled steel sheet is subjected to finish annealing,
The finish annealing is performed by cooling from 700 ° C. to 500 ° C. over 1 to 300 seconds in an oxidizing atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0010 or more. A method of manufacturing a steel sheet. % By mass
C: 0.0050% or less,
Si: 6.00% or less,
Mn: 0.050% to 3.00%,
P: 0.100% or less,
S: 0.0050% or less,
N: 0.0050% or less,
Al: 0.0050% or less and B: 0.00030% or less,
A steel slab containing Sn: 0.05% or more and 0.50% or less and / or Sb: 0.05% or more and 0.50% or less, with the balance being composed of Fe and inevitable impurities, hot-rolled into a hot-rolled steel sheet,
Pickling the hot-rolled steel sheet;
The hot-rolled steel sheet subjected to pickling is cold-rolled steel sheet by subjecting the hot-rolled steel sheet to cold rolling twice or more sandwiching one or intermediate annealing,
A method for producing a non-oriented electrical steel sheet that is coated after the cold-rolled steel sheet is subjected to finish annealing,
The rolling reduction in cold rolling immediately before the finish annealing is 85% or more,
The finish annealing is performed by cooling from 700 ° C. to 500 ° C. over 1 to 300 seconds in an oxidizing atmosphere having an oxygen potential PH ₂ O / PH ₂ of 0.0010 or more. A method of manufacturing a steel sheet. The component composition further includes:
% By mass
The method for producing a non-oriented electrical steel sheet according to any one of claims 4 to 6, comprising As: 0.0050% or less. The component composition further includes:
% By mass
Ca: 0.0001% or more and 0.0300% or less,
REM: 0.0001% to 0.0300% and
The method for producing a non-oriented electrical steel sheet according to any one of claims 4 to 7, comprising Mg: one or more selected from 0.0001% to 0.0300%.

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