KR101353462B1 - Non-oriented electrical steel shteets and method for manufactureing the same - Google Patents

Abstract

The present invention relates to a non-oriented electrical steel sheet and a method for manufacturing the same, in weight percent (%), C: 0.005% or less, Si: 1.0 ~ 4.0%, Al: 0.3 ~ 0.8%, Mn: 0.01 ~ 0.2%, P : 0.02 to 0.3%, N: 0.005% or less, S: 0.001 to 0.005%, Ti: 0.005% or less, the balance includes Fe and other unavoidable impurities, and the component system is [Mn] <[P], By providing a non-oriented electrical steel sheet and a method of manufacturing the same satisfying the following compositional expression,
0.02≤ {[Ti] * ([C] + [N])} / {[Mn] * [S]} ≤10,
(However, [Ti], [C], [N], [Mn], [S], and [P] are the weight percentages of Ti, C, N, Mn, S, and P, respectively.)
Inhibit the formation of fine Ti (C, N) inclusions and form coarse sulfides of (Mn, Cu, Ti) S to control the growth of grains by controlling the number of sulfides of (Mn, Cu, Ti) S containing Ti By smoothly moving the magnetic domain wall can improve the high-frequency magnetism of the non-oriented electrical steel sheet.

Description

Non-oriented electrical steel sheet and manufacturing method {NON-ORIENTED ELECTRICAL STEEL SHTEETS AND METHOD FOR MANUFACTUREING THE SAME}

The present invention relates to a non-oriented electrical steel sheet and a method for manufacturing the same, and more particularly, to control the component system of the electrical steel sheet to suppress the formation of fine inclusions that interfere with grain growth and the movement of the magnetic wall and to produce more coarse inclusions An improved non-oriented electrical steel sheet and a method of manufacturing the same.

In general, non-oriented electrical steel sheet is used as a material for iron cores in rotating devices such as motors and generators and stationary devices such as small transformers, and is used to convert electrical energy into mechanical energy. Therefore, the non-oriented electrical steel sheet plays an important role in determining the energy efficiency of the electrical equipment, and the recent demand for energy saving, miniaturization of the electrical equipment has increased the demand for improving the characteristics of the non-oriented electrical steel sheet. The good magnetic properties of electrical steel mean that the iron loss is small and the magnetic flux density is high. This means that when iron is added to the core to induce a magnetic field, the lower the iron loss, the less energy is lost to heat. This is because the same energy can induce a larger magnetic field.

Among the magnetic properties of non-oriented electrical steel sheet, in order to improve the iron loss at high frequencies, a method of adding Si, Al, Mn, etc., which are alloy elements having a large resistivity, is generally used to increase electrical resistance. However, when the alloying element is added, the iron loss is reduced, but the decrease in the magnetic flux density is also inevitable due to the decrease in the saturation magnetic flux density.

Therefore, in order to lower the iron loss and improve the magnetic flux density, the addition of a trace alloy element increases the {100} texture, which is advantageous to magnetic properties, and reduces the {111} texture, which is harmful, or impurity. Techniques for producing clean steel by minimizing the amount of copper have been used. However, since these technologies cause an increase in manufacturing cost and the difficulty of mass production, it is necessary to have a technology with excellent magnetic improvement effect without increasing the manufacturing cost significantly.

Japanese Laid-Open Patent Publication No. 1997-125144 is characterized in that the rolling amount is terminated on austenite during hot rolling by reducing the amount of alloy, which is disadvantageous in that the texture is inferior to the texture rolled on the ferrite and the grain size is fine. There is a need for a process of adding pass rolling. In addition, U.S. Patent No. 6,531,001 manages Al to 0.1% or less, and there is a problem that impurities such as AlN may worsen the texture.

Embodiments of the present invention by controlling the components of Ti, C, N, Mn, S of the alloy elements of the steel to form Ti with a spherical type sulfide such as (Mn, Cu, Ti) S together with Mn and fine Ti inclusions It is an object of the present invention to provide a non-oriented electrical steel sheet and a method of manufacturing the same to suppress the formation and increase the distribution of coarse inclusions.

In one or more embodiments of the present invention, in weight percent (%), C: 0.005% or less, Si: 1.0-4.0%, Al: 0.3-0.8%, Mn: 0.01-0.2%, P: 0.02-0.3% , N: 0.005% or less, S: 0.001% to 0.005%, Ti: 0.005% or less, the balance includes Fe and other unavoidable impurities, and the component system is [Mn] <[P]. Satisfactory non-oriented electrical steel sheet may be provided.

0.02≤ {[Ti] * ([C] + [N])} / {[Mn] * [S]} ≤10,

(However, [Ti], [C], [N], [Mn], [S], and [P] are the weight percentages of Ti, C, N, Mn, S, and P, respectively.)

In one or more embodiments of the present invention may include 0.01 to 0.2% by weight of at least one of Sn and Sb, the microstructure of the electrical steel sheet may include a sulfide of (Mn, Cu, Ti) S, The number of sulfides is 1/10 ⁴ ㎛ ² ~ 10/10 ⁴ ㎛ ² , the average size is characterized in that more than 0.1㎛.

In addition, in one or more embodiments of the present invention, the weight percentage (%), C: 0.005% or less, Si: 1.0-4.0%, Al: 0.3-0.8%, Mn: 0.01-0.2%, P: 0.02-- 0.3%, N: 0.005% or less, S: 0.001% to 0.005%, Ti: 0.005% or less, the balance includes Fe and other unavoidable impurities, [Mn] <[P], and the following compositional formula Providing a satisfying slab; Reheating the slab to 1200 ° C. or less and rolling the slab to produce a hot rolled steel sheet; Manufacturing a cold rolled steel sheet having a thickness of 0.10 to 0.70 mm after pickling the hot rolled steel sheet; A non-oriented electrical steel sheet manufacturing method for annealing the cold rolled steel sheet at 850 ~ 1100 ℃ can be provided.

0.02≤ {[Ti] * ([C] + [N])} / {[Mn] * [S]} ≤10,

(However, [Ti], [C], [N], [Mn], [S], and [P] are the weight percentages of Ti, C, N, Mn, S, and P, respectively.)

In one or more embodiments according to the present invention, the inevitable added impurities include one or more of Cu, Ni, Cr, Zr, Mo, and V, wherein Cu, Ni, and Cr are each 0.05 weight percent (%). Limited to below, the Zr, Mo, V is characterized in that each limited to less than 0.01% by weight (%).

Embodiments of the present invention inhibit the formation of fine Ti (C, N) inclusions and form coarse sulfides of (Mn, Cu, Ti) S to form Ti sulfides of (Mn, Cu, Ti) S It is possible to improve the high-frequency magnetism of the non-oriented electrical steel sheet by controlling the grain growth and the movement of the magnetic domain wall smoothly.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention, and are not intended to limit the scope of the inventions. I will do it.

In the embodiment according to the present invention, a large amount of Al and P, which are ferrite expansion elements, are added, that is, 0.3 to 0.8% of Al, and P is added to at least Mn. In doing so, the amounts of Mn and Ti, C, S, and N which are impurity elements are strictly controlled. The amount of Mn is 0.01 to 0.2%, Ti, C and N are controlled to 0.005% or less, and S is controlled to 0.001 to 0.005% to suppress the formation of fine Ti (C, N) and the like. In addition, coarse sulfides such as (Mn, Cu, Ti) S were formed to increase the distribution density of coarse inclusions, thereby improving high frequency magnetism.

To this end, in the embodiment according to the present invention by weight percent (%), Si: 1.0 ~ 4.0%, Al: 0.3 ~ 0.8%, Mn: 0.01 ~ 0.2%, P: 0.02 ~ 0.3%, N: 0.005% or less, S: 0.001% to 0.005%, the balance includes Fe and other inevitable impurities, [Mn] <[P], and Mn, Al, P, and S are provided by a non-oriented electrical steel sheet satisfying the following formula: do.

0.02≤ {[Ti] * ([C] + [N])} / {[Mn] * [S]} ≤10 ----------------- (1)

[Mn], [S], [Al], and [P] mean weight percent of Mn, S, Al, and P, respectively.

First, look at the reasons for component limitation in the embodiment according to the present invention.

Si: 1.0 to 4.0 wt%

The Si is a main element added because it increases the specific resistance of the steel and lowers the vortex loss in iron loss, and it is difficult to obtain low iron loss characteristics below 1.0%, and when added in excess of 4.0%, breakage occurs during cold rolling. It is limited to ~ 4.0% by weight.

Mn: 0.01% to 0.2% by weight

The Mn is added for the purpose of improving iron loss because it has an effect of lowering iron loss by increasing specific resistance together with Si and Al. However, as the amount of Mn added increases, the saturation magnetic flux density decreases, so the magnetic flux density decreases. have. Therefore, in order to improve the magnetic flux density and prevent the increase of iron loss by inclusions, the amount of Mn added is limited to 0.01 to 0.2%.

Al: 0.3-0.8 wt%

The above Al is an inevitably added element for steel deoxidation in the steelmaking process, which is a major element for increasing the resistivity. Therefore, it is added in order to lower the iron loss, but also serves to decrease the saturation flux density. In addition, if the amount of Al added is less than 0.3%, the specific resistance is excessively low, and the iron loss is lowered, especially in high frequency steel, and if it is added more than 0.8%, the magnetic flux density is reduced, so the amount of addition is limited to 0.3 ~ 0.8%. do.

P: 0.02 to 0.3 wt%

P is added to increase the resistivity, lower the iron loss and segregate at grain boundaries, thereby inhibiting formation of {111} aggregates that are harmful to magnetism and forming {100}, which is an advantageous texture. Since the improvement effect is reduced, it is preferable to add at 0.02-0.3 weight%. Mn is an element that suppresses the formation of ferrite, while P is an element that expands the ferrite phase, which is more stable during hot rolling and annealing by containing more P content than Mn to satisfy the formula of [Mn] <[P]. Can work on ferrite to improve the desirable texture of magnetism so that the ratio of {100} / {110} is over 1.5

C: 0.005 wt% or less

When C is added a lot, the austenite region is enlarged, the phase transformation period is increased, and ferrite grain growth is suppressed by annealing to increase iron loss, and it is inferior to magnetism by forming carbides in combination with Ti. In order to increase iron loss by self aging, it should be limited to 0.005% or less.

S: 0.001 to 0.005% by weight or less

S is an element which forms sulfides such as MnS, CuS, and (Cu, Mn) S, which are detrimental to magnetic properties. Therefore, it is preferable to add S as low as possible. However, if it is added below 0.001%, the magnetism is deteriorated due to the disadvantage of the formation of aggregates, and if it is added more than 0.001%, the content is more than 0.005% due to the increase of the fine sulfide, which causes the heat to become 0.001 ~ 0.005% It is limited to.

N: 0.005 wt% or less

N is an element which is harmful to magnetism, such as to form nitrides by strongly bonding with Al, Ti and the like to inhibit grain growth, and therefore it is preferable to contain N less than 0.005% by weight or less.

Ti: 0.005 wt% or less

Ti suppresses grain growth by forming fine carbides and nitrides, and as the amount of Ti increases, the carbides and nitrides increase inferior texture due to increased carbides and nitrides.

Sn or Sb: 0.01 to 0.2 wt%

The Sn and Sb are added to improve the magnetic properties by inhibiting the diffusion of nitrogen through the grain boundary as a segregation element in the grain boundary, inhibiting {111} texture harmful to magnetism and increasing the advantageous {100} texture. If Sn or Sb alone or a sum of 0.2% or more is added, the grain growth is suppressed to decrease the magnetism and the rolling property worsens. Therefore, Sn or Sb alone or the sum thereof is added at 0.01 to 0.2%.

In addition to the above elements, Cu, Ni, and Cr, which are inevitably added in the steelmaking process, react with the impurity elements to form fine sulfides, carbides, and nitrides, which have a harmful effect on magnetism. Restrict. In addition, Zr, Mo, and V is also a strong carbonitride-forming element, so it is preferable not to be added as much as possible.

In addition to the above composition, the remainder is composed of Fe and other unavoidable impurities. In the embodiment according to the present invention, P must be added more than Mn, because P affects the texture.

In addition, if the Al content is increased to 0.3% as much as 0.3% or more and the P content is contained at least Mn to satisfy the formula of [Mn] <[P], the fine precipitates are suppressed even when the Mn content is increased, thereby improving the magnetic properties. Can be. Therefore, in the non-oriented electrical steel sheet having 0.3 to 0.8% of Al and 0.001 to 0.005% of S, Mn is contained in 0.01 to 0.2% and P is contained in 0.02 to 0.3%, but satisfies [Mn] <[P]. By adding P higher than Mn, the high frequency magnetism is improved.

Mn is an element that suppresses the formation of ferrite, whereas Al and P are elements that expand the ferrite phase, so that the ferrite forming elements Al and P are increased to work on a stable ferrite phase during hot rolling and annealing, and P is a grain boundary. By segregating in the well-developed {100} texture, which is advantageous for magnetism, the magnetic properties can be improved.

In the embodiment according to the present invention, the element added is Si, Mn, Al, P or Sn, and Sb, and the other elements to be added are impurity elements. However, Ti, C, N, S, etc. must be strictly managed. Inclusions of non-oriented electrical steel sheets include MnS, CuS, or their complex sulfides, AlN, Ti (C, N), etc., and generally have a size of about 0.05 μm, which suppresses grain growth and impedes movement of the magnetic domain walls. It will have a big impact on magnetism. Particularly, Ti (C, N) has a small size and the inclusion shape is a cubic type rather than a spherical type. Therefore, there is a need to suppress the formation of such fine Ti (C, N) inclusions and to increase the frequency of formation of coarse inclusions so as to minimize magnetic deterioration.

To this end, in an embodiment according to the present invention, Ti, C, N, Mn, and S are controlled to satisfy the composition relation (1), so that Ti is formed of fine cubic Ti (C, N) inclusions, unlike Mn, Coarse sulfides such as spherical type (Mn, Cu, Ti) S together with Cu are formed, and the number of sulfides such as (Mn, Cu, Ti) S containing Ti having a size of 0.05 μm to 0.5 μm is 1 number / 10 and ⁴ ㎛ ² ~ ² 10 number / 10 ⁴ ㎛, observed a phenomenon in which the average size, such as the (Mn, Cu, Ti) S contains a Ti having a size of 0.05 ~ 0.5㎛ becomes equal to or greater than 0.1㎛ By adjusting the distribution density of these inclusions, the high-frequency magnetism is improved by lowering iron loss and increasing magnetic flux density of the non-oriented electrical steel sheet.

In the embodiment according to the present invention as a method for analyzing the size, type and distribution of inclusions was used to observe the carbon replica (sample) extracted from the specimen (TEM) by TEM analysis. TEM observation was set at a magnification in which at least 0.01 μm of inclusions were clearly observed in a randomly selected area without bias, and then measured the size, shape, and distribution of all inclusions appearing by taking at least 100 images. The types of inclusions were analyzed by spectrum. In analyzing the size and distribution of inclusions in the embodiment according to the present invention, the inclusions of 0.01 μm or less are not only difficult to observe and measure, but also have a small effect on magnetism, and SiO ₂ , Al ₂ O ₃ and 1 μm or more. The same oxides were also observed but the effect on the magnet was small and was not included in the analyte of the present invention.

In the embodiment according to the present invention, the range of {[Ti] * ([C] + [N])} / {[Mn] * [S]} is limited to the compositional relationship (1), because the Ti and C The amount of, N has a significant effect on the size and distribution of Ti (C, N) inclusions, and the amount of Mn, S is important for determining the distribution and size of inclusions, especially sulfides, and thus affects Ti, C, N The addition ratio of Mn and S has a very important effect in forming distribution and size of inclusions. When the value of the composition relation expression is smaller than 0.02 or larger than 10, Ti is finely formed as Ti (C, N) and the inclusions are not coarsened so that the distribution density of the fine inclusions is increased, thereby suppressing grain growth and moving the domain. It interferes with magnetism such as obstruction.

Hereinafter, look at the manufacturing method of the non-oriented electrical steel sheet according to the present invention.

The non-oriented steel sheet steel slab prepared as described above is reheated to a temperature of 1200 DEG C or less and then hot rolled. If the reheating temperature is more than 1200 ℃ re-heating temperature is limited to less than 1200 ℃ because the precipitates such as AlN, MnS existing in the slab is re-used and fine precipitated during hot rolling to inhibit grain growth and decrease the magnetism. Finishing rolling in hot rolling is finished in ferrite phase and final rolling reduction is 20% or less for plate shape calibrating.

The hot rolled sheet prepared as described above is wound at 700 ° C. or lower and cooled in air. The coiled and cooled hot rolled sheet is subjected to hot rolled sheet annealing and pickling as necessary, followed by cold rolling and finally cold rolled sheet annealing.

The hot rolled sheet annealing is to anneal the hot rolled sheet if necessary to improve the magnetic, the hot rolled sheet annealing temperature is set to 850 ~ 1150 ℃. When the hot-rolled sheet annealing temperature is lower than 850 ° C, grain growth is insufficient. When the hot-rolled sheet annealing temperature is lower than 850 ° C, the grains grow excessively and the surface defects of the plate become excessive, so the annealing temperature is set to 850-1150 ° C.

Thereafter, the hot rolled sheet or the annealed hot rolled sheet pickled by a conventional method is cold rolled.

In the cold rolling step, the final rolling is carried out to a thickness of 0.10 ~ 0.70mm. If necessary, it can be subjected to primary cold rolling and intermediate annealing followed by secondary cold rolling, and the final rolling reduction is in the range of 50 to 95%.

Thereafter, the final cold rolled cold rolled steel sheet is annealed. In the annealing process of the cold rolled steel sheet, the cracking temperature of the cold rolled sheet annealing is 850 ~ 1100 ℃. When the cold-rolled sheet annealing temperature is lower than 850 ℃, the grain growth is insufficient, the ratio of {100} / {110} decreases, and the grains grow excessively above 1100 ℃, which may adversely affect the magnetic properties of the cold-rolled sheet The cracking temperature is set at 850 ~ 1100 ℃.

Hereinafter, embodiments according to the present invention will be described in more detail.

[Example 1]

The steel ingot was prepared as shown in Table 1 to change the amount of Ti, C, N, Mn, S, P to see the effect. Each ingot was heated at 1150 ° C., hot rolled to a thickness of 2.5 mm and wound up. The hot rolled steel sheet wound and cooled in air was annealed at 1060 ° C. for 4 minutes, pickled, and cold rolled to a thickness of 0.35 mm, and the cold rolled sheet annealing was finally annealed at 1060 ° C. for 100 seconds. For each specimen, the number and size of the (Mn, Cu, Ti) S sulfide, texture, iron loss and magnetic flux density were measured and the results are shown in Table 2 below.

Steel grade C Si Mn P S Al N Ti Sn Sb Remarks
A1 0.0021 1.2 0.03 0.20 0.003 0.35 0.0021 0.0016 0.036 Honor A2 0.0025 2.0 0.01 0.25 0.004 0.32 0.0023 0.0019 0.034 Honor A3 0.0029 2.6 0.05 0.08 0.002 0.41 0.002 0.0025 0.015 0.02 Honor A4 0.0025 2.5 0.002 0.08 0.003 0.006 0.0021 0.0015 0.035 Comparative Example A5 0.0021 2.4 0.02 0.05 0.003 1.5 0.0015 0.0025 0.036 0.01 Comparative Example A6 0.0024 2.5 0.06 0.01 0.003 0.27 0.0021 0.0023 0.044 Comparative Example A7 0.0025 2.6 1.5 0.05 0.0005 0.51 0.0021 0.0021 0.02 Comparative Example A8 0.0038 3.4 0.55 0.08 0.003 0.56 0.0017 0.0026 Comparative Example A9 0.0035 3.2 0.01 0.18 0.001 0.45 0.0025 0.0038 Honor A10 0.0025 3.1 0.18 0.20 0.001 0.46 0.0015 0.0015 0.048 Honor A11 0.0026 3.2 0.07 0.25 0.003 0.45 0.0014 0.0021 0.039 Honor A12 0.0028 3.6 0.03 0.12 0.004 0.43 0.0015 0.0026 Honor A13 0.0023 3.9 0.05 0.07 0.002 0.35 0.002 0.0024 0.048 Honor A14 0.0026 3.8 0.06 0.02 0.004 0.4 0.0017 0.0021 0.045 Comparative Example A15 0.0028 3.5 0.03 0.04 0.0005 0.27 0.0019 0.0024 0.03 Comparative Example A16 0.0025 3.1 0.12 0.06 0.003 0.31 0.0021 0.0024 0.041 Comparative Example

Steel grade [Mn] < [P] {[Ti] * ([C] + [N])}
Of
{[Mn] * [S]} Number of (Mn, Cu, Ti) S of 0.05 ~ 0.5μm size
(Piece / 10 ⁴ μm ² ) Iron loss
(W _10/400)
W / kg Magnetic flux
density
(B ₅₀ )
Tesla Remarks A1 O 0.07 2.1 18.1 1.79 Honor A2 O 0.23 2.4 15.5 1.78 Honor A3 O 0.12 1.8 14.3 1.77 Honor A4 O 1.15 0.8 18.8 1.68 Comparative Example A5 O 0.15 0.7 19.4 1.69 Comparative Example A6 X 0.06 0.4 20.3 1.67 Comparative Example A7 X 0.01 0.6 19.5 1.66 Comparative Example A8 X 0.01 0.8 18.9 1.65 Comparative Example A9 O 2.28 2.6 14.3 1.74 Honor A10 O 0.03 4.5 14.5 1.79 Honor A11 O 0.04 3.5 13.5 1.75 Honor A12 O 0.09 3.2 12.9 1.74 Honor A13 O 0.10 2.6 12.5 1.75 Honor A14 X 0.04 0.6 19.5 1.65 Comparative Example A15 O 0.75 0.8 20.8 1.66 Comparative Example A16 X 0.03 0.7 19.4 1.64 Comparative Example

1) _Iron loss (W _10/400 ) is the average loss (W / kg) in the rolling direction and the vertical direction when the magnetic flux density of 1.0 Tesla is induced at 400 Hz.

2) Magnetic flux density (B ₅₀ ) is the magnitude of magnetic flux density (Tesla) induced when a magnetic field of 5000 A / m is added.

As shown in Table 2, [Ti], [C], [N], [Mn], [S], and [P] of the present invention are [Mn] <[P], and 0.02≤ {[Ti] * ([C] + [N])} / {[Mn] * [S]} Steel grades A1 to A3 and A9 to A13 satisfying the compositional formula of (10) are (Mn, Cu, Ti) having a size of 0.05 to 0.5 µm. The number of S (dog / 10 ⁴ μm ² ) was also 1-10, and the average size of (Mn, Cu, Ti) S was 0.1 μm or more. As a result, the iron loss at high frequency was high and the magnetic flux density was high.

In detail, A4, which is a comparative example, has [Mn] <[P], but Al and S do not satisfy the range, A5 has excessive Al content, and A6 has low P and Al. A7 and A8 are [Mn] <[P], and A7 has a low S. A14-16 were [Mn] <[P, and other elements also did not satisfy the scope of the invention, and it was investigated that magnetism was insufficient.

[Example 2]

   By weight, C: 0.0021%, Si: 3.06%, Mn: 0.05%, P: 0.18%, S: 0.0015%, Al: 0.45%, N: 0.0014%, Ti: 0.0017%, remaining Fe and other unavoidable impurities The slab, which was composed of a slab, was reheated to 1170 ° C. and then made into a hot rolled steel sheet having a thickness of 2.0 mm, wound up to 640 ° C., and cooled in air. [Mn] <[P], and the value of {[Ti] * ([C] + [N])} / {[Mn] * [S]} was 0.8. The hot rolled sheet was continuously annealed and pickled for 3 minutes as shown in Table 3, cold rolled to a thickness of 0.2 mm, and the cold rolled sheet was annealed at 70% nitrogen and 30% hydrogen for 1 minute.

The number and size of (Mn, Cu, Ti) S sulfides, high frequency iron loss and magnetic flux density for each specimen are shown in Table 4 below.

division Hot-rolled plate
Temperature (℃) Annealing temperature of cold rolled sheet (℃) Number of (Mn, Cu, Ti) S of 0.05 ~ 0.5μm size (piece / 10 ⁴ μm ² ) Iron loss
(W10 / 400)
(W / kg) Magnetic flux density
B50 N _{s ≥0.1 μm}
/ N _Tot
Remarks B1 1050 950 2.10 9.9 1.70 0.65 Honor B2 1050 1000 2.35 9.5 1.69 0.55 Honor B3 1050 1050 2.70 10.1 1.71 0.58 Honor B4 800 1000 0.75 12.5 1.62 0.45 Comparative Example B5 1050 800 0.91 14.9 1.63 0.35 Comparative Example B6 1200 1050 0.84 13.9 1.64 0.35 Comparative Example

The present invention satisfies [Ti], [C], [N], [Mn], [S], and [P] of the present invention, {Mn} <[P], and satisfies the compositional expression (1). Steel grades B1 to B3 which satisfy the hot rolled sheet annealing temperature and cold rolled sheet annealing temperature are also shown as 1 ~ 10 (Mn, Cu, Ti) S number (10/10 ⁴ ㎛ ² ) of 0.05 ~ 0.5㎛ size. Low and high magnetic flux density.

On the other hand, B4 ~ B6, the hot-rolled sheet annealing temperature and the final annealing temperature is out of the scope of the present invention, the number of (Mn, Cu, Ti) S of 0.05 ~ 0.5㎛ size (10/10 ⁴ ㎛ ² ) is also shown as one or less The average size was also small, indicating that high frequency iron loss and magnetic flux density were inferior.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And all changes to the scope that are deemed to be valid.

Claims (12)

In weight percent (%), C: 0.005% or less (0%), Si: 1.0-4.0%, Al: 0.3-0.8%, Mn: 0.01-0.2%, P: 0.02-0.3%, N : 0.005% or less (does not contain 0%), S: 0.001% to 0.005%, Ti: 0.005% or less (does not contain 0%), and the balance includes Fe and other unavoidable impurities. [Mn] <[P], satisfying the following compositional expression,
0.02≤ {[Ti] * ([C] + [N])} / {[Mn] * [S]} ≤10,
(However, [Ti], [C], [N], [Mn], [S], and [P] are the weight percentages of Ti, C, N, Mn, S, and P, respectively.)
Non-oriented electrical steel sheet, characterized in that the number of (Mn, Cu, Ti) S sulfide in the microstructure of the electrical steel sheet is 1/10 ⁴ ㎛ ² ~ 10/10 ⁴ ㎛ ² . The method of claim 1,
Non-oriented electrical steel sheet containing 0.01 to 0.2% by weight of at least one of Sn and Sb. 3. The method according to claim 1 or 2,
The inevitably added impurities include at least one of Cu, Ni, Cr, Zr, Mo, and V, wherein Cu, Ni, and Cr are each limited to 0.05 weight percent (%) or less, and the Zr, Mo, and V The non-oriented electrical steel sheets are each limited to 0.01% by weight or less. delete delete 3. The method according to claim 1 or 2,
The non-oriented electrical steel sheet, characterized in that the average size of the sulfide is 0.1㎛ or more. In weight percent (%), C: 0.005% or less (0%), Si: 1.0-4.0%, Al: 0.3-0.8%, Mn: 0.01-0.2%, P: 0.02-0.3%, N : 0.005% or less (does not contain 0%), S: 0.001% to 0.005%, Ti: 0.005% or less (does not contain 0%), the balance includes Fe and other unavoidable impurities, [Mn Providing a slab satisfying the following compositional relationship;
0.02≤ {[Ti] * ([C] + [N])} / {[Mn] * [S]} ≤10,
(However, [Ti], [C], [N], [Mn], [S], and [P] are the weight percentages of Ti, C, N, Mn, S, and P, respectively.)
Reheating the slab to 1200 ° C. or less and rolling the slab to produce a hot rolled steel sheet;
Manufacturing a cold rolled steel sheet having a thickness of 0.10 to 0.70 mm after pickling the hot rolled steel sheet;
Final annealing the cold rolled steel sheet at 850 ℃ ~ 1100 ℃,
Method for producing a non-oriented electrical steel sheet, characterized in that the number of sulfides of (Mn, Cu, Ti) S in the microstructure of the finished steel sheet is finished 1/10 ⁴ ㎛ ² ~ 10/10 ⁴ ㎛ ² . The method of claim 7, wherein
Non-oriented electrical steel sheet manufacturing method containing 0.01 to 0.2% by weight of at least one of Sn and Sb. 9. The method according to claim 7 or 8,
The inevitably added impurities include at least one of Cu, Ni, Cr, Zr, Mo, and V, wherein Cu, Ni, and Cr are each limited to 0.05 weight percent (%) or less, and the Zr, Mo, and V The non-oriented electrical steel sheet manufacturing method is added to each 0.01% by weight or less. delete delete 10. The method of claim 9,
Method for producing a non-oriented electrical steel sheet, characterized in that the average size of the sulfide is 0.1㎛ or more.