KR20160021164A - Non-oriented electrical steel sheets and method for manufacturing the same - Google Patents

Abstract

Disclosed are a non-oriented electrical steel sheet and a manufacturing method thereof. According to the present invention, the non-oriented electrical steel sheet comprises 0.005 wt% or lower of C (does not include 0 wt%), 0.68-1.79 wt% of Si, 0.14-0.82 wt% of Mn, 0.02 wt% or lower of P (does not include 0 wt%), 0.001-0.005 wt% of S, 0.11-0.42 wt% of Al, 0. 005 wt% or lower of N (does not include 0 wt%), 0.005 wt% or lower of Ti (does not include 0 wt%), 0.05-0.2 wt% of at least one among Sn and Sb, and the remainder consisting of Fe and inevitable impurities. Si, Al, and Mn satisfy 0.7<=([Si]+[Al]-[Mn])<=1.7 and [Mn]>=[Al], where [Si], [Al], and [Mn] mean the weight percentages (%) of Si, Al, and Mn, respectively.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-oriented electrical steel sheet,

The present invention relates to a non-oriented electrical steel sheet, and more particularly, to a non-oriented electrical steel sheet having an excellent magnetic property by controlling the composition system optimally.

The nonoriented electric steel sheet is used as an iron core material in rotating devices such as motors, generators, and stationary devices such as small transformers, and plays an important role in determining the energy efficiency of electric devices.

The characteristics of the electric steel sheet include iron loss and magnetic flux density. The iron loss is small and the magnetic flux density is high, which is preferable. When the magnetic field is induced by adding electricity to the iron core, the lower the iron loss, And the higher the magnetic flux density, the larger the magnetic field can be induced with the same energy.

In order to reduce iron loss, Si, Al, Mn, etc., which are alloying elements with high resistivity, are added. This method has a problem that the iron loss is reduced but the saturation magnetic flux density is also decreased.

If the amount of Si added is 4% or more, the workability is lowered, which makes cold rolling difficult, resulting in a decrease in productivity and a large amount of Al and Mn. The more the addition is made, the lower the rolling property is, and the hardness is increased and the workability is lowered.

Disclosure of Invention Technical Problem [8] The present invention has been made to solve the above problems, and it is an object of the present invention to provide a non-oriented electrical steel sheet having a low iron loss and excellent magnetic properties by optimally controlling components of S, Al and Mn among alloying elements of steel.

The non-oriented electrical steel sheet according to one embodiment of the present invention is characterized by containing 0.005% or less of C (not including 0%), 0.68 to 1.79% of Si, 0.14 to 0.82% or less of Mn, 0.14 to 0.82% : Not more than 0.02% (not including 0%), S: 0.001 to 0.005%, Al: 0.11 to 0.42%, N: 0.005% [Si] + [Al] - [Si] and at least one of Sn and Sb is 0.05 to 0.2%, and the balance includes Fe and other inevitably added impurities. Mn]) ≤1.7 and [Mn] ≥ [Al], where [Si], [Al], and [Mn] mean weight percentage (%) of Si, Al and Mn, respectively.

Further, the non-oriented electrical steel sheet may satisfy V _{110} &gt; ₌ 0.2 (where V _{110} represents the fraction of {110}

In addition, to meet the above non-oriented electrical steel sheet is (V + V _{(111) {112})} ≤0.6. (Wherein, V ₍₁₁₁₎ is the fraction of the {111} texture on the sum of the orientation, _{{V 112}} means the fraction of the {112} texture of the sum of all orientations)

The size of the crystal grains in the microstructure of the electrical steel sheet may be 20 to 120 탆.

The contents of Cu, Ni and Cr are added in an amount of 0.05 wt% or less, respectively, and the content of Zr, Mo and V is Each may be added in an amount of 0.01 wt% or less.

A method for producing a non-oriented electrical steel sheet according to an embodiment of the present invention comprises: 0.005% or less (excluding 0%) of C, 0.68 to 1.79% of Si, 0.14 to 0.82% of Mn, , P: not more than 0.02% (not including 0%), S: 0.001 to 0.005%, Al: 0.11 to 0.42%, N: 0.005% (Si) + [Al], and the balance of Fe and other inevitably added impurities, wherein Si, Al and Mn are in the range of 0.7? ([Si] + [Al] - [Mn]) ≤1.7 and [Mn] ≥ [Al], where [Si], [Al], and [Mn] refer to weight percent ; Heating the slab to 1,200 ° C or less and then rolling to produce a hot-rolled steel sheet; Pickling the hot-rolled steel sheet and rolling it to 0.10 to 0.70 mm to produce a cold-rolled steel sheet; And finishing annealing the cold-rolled steel sheet at 850 to 1,100 ° C.

Further, in the step of manufacturing the hot-rolled steel sheet, finish rolling may be characterized in that it finishes in a ferrite single-phase region of {A ₁ temperature (° C) - 70 ° C} or lower.

And further annealing the hot-rolled steel sheet at a temperature of 1,000 to 1,200 ° C, wherein the annealing of the hot-rolled sheet is performed in a single-phase austenite region having an A ₃ temperature (° C) or higher.

Further, the electrical steel sheet after completion of the finish annealing can satisfy V _{110} &gt; ₌ 0.2 (where V _{110} means a fraction of {110}

Further, the electrical steel sheet after completion of the finish annealing can satisfy (V _{111} + V _{112} )? 0.6. (Where V _{111} is the fraction of {111} texture for the sum of all orientations and V _{112} is the fraction of {112} texture of the sum of all orientations)

The size of the crystal grains in the microstructure of the electric steel sheet after finishing annealing is 20 to 120 mu m.

The contents of Cu, Ni and Cr are added in an amount of 0.05 wt% or less, respectively, and the content of Zr, Mo and V is Each may be added in an amount of 0.01 wt% or less.

Non-oriented electrical steel sheet according to the present invention is a S, Al, Mn, Sn, and controls the component of Sb the best iron loss (W _15/50) is 3.1W / Kg or less, the magnetic flux density (B ₅₀₎ at least 1.76T It is possible to produce a non-oriented electrical steel sheet having excellent iron loss reduction ratio and remarkably improved magnetic properties.

Further, the non-oriented electrical steel sheet according to the present invention is controlled by 0.7? ([Si] + [Al] - [Mn])? 1.7 so as to undergo phase transformation during the heat treatment, And the {111}, {112} texture which is disadvantageous to magnetism can be reduced, thereby improving the magnetism.

In addition, the non-oriented electrical steel sheet according to the invention finish rolling-set by subjecting {A ₁ temperature (℃) 70 ℃} and carried out in the ferrite single-phase region hereinafter, the hot-rolled sheet annealing is in the austenite single-phase region or more A ₃ temperature The magnetic properties can be improved by increasing the {100} and {110} texture structures favorable to magnetism by improving the structure and reducing {111} and {112} texture structures unfavorable to magnetism.

It is also possible to optimize the S, Al, and Mn components while minimizing the addition amount of the alloy element by adding the Si content of 2 wt% or less, the Mn content of 0.1-1.0 wt% or less, and the Al content of 0.1-0.5 wt% A non-oriented electrical steel sheet excellent in magnetic flux density and improved in iron loss and a manufacturing method thereof are provided.

In addition, the non-oriented electrical steel sheet produced by the present invention has excellent magnetic properties, so that it is possible to omit additional processes such as decarburization annealing for improving magnetic properties, thereby improving the economical efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a non-oriented electrical steel sheet according to a preferred embodiment of the present invention will be described.

The non-oriented electrical steel sheet according to the preferred embodiment of the present invention is characterized by containing, by weight percent, C: 0.005% or less (excluding 0%), Si: 0.68-1.79, Mn: 0.14-0.82% (Inclusive of 0%), S: 0.001 to 0.005%, Al: 0.11 to 0.42%, N: 0.005% or less ), 0.05 to 0.2% of at least one of Sn and Sb, and the balance contains Fe and other inevitably added impurities,

Wherein [Si], [Al], and [Mn] are Si, Al, and Mn, (%) Of Al and Mn).

The reasons for limiting the content of the non-oriented electrical steel sheet according to the present invention are as follows.

Si: 0.68 to 1.79 wt%

The Si is a main element added to increase the resistivity of the steel to lower the vortex loss in iron loss. However, it is difficult to obtain the characteristics of the high magnetic flux density as the addition amount is increased as the addition amount increases. When Si is more than 1.79 wt% When added, it is preferable to limit the addition amount to 1.79 wt% or less, because the ferrite structure hardly contains phase transformation in the production process and is heat-treated only in the ferrite structure to improve the texture.

Mn: 0.14 to 0.82 wt%

In addition to Si and Al, the Mn is an element that lowers iron loss by increasing resistivity, and is an element that improves the texture. In addition, as the austenite stabilizing elements Si and Al are added to the ferrite stabilizing element, the phase transformation temperature is increased and the phase transformation period is decreased as the addition amount thereof is increased. However, when it is added too much, the phase transformation temperature is lowered and the magnetic flux density is also decreased, so that the addition amount is limited to 0.14 to 0.82 wt%.

Al: 0.11-0.42 wt%

The Al is added because it increases the specific resistance and decreases the iron loss and also reduces the magnetic anisotropy and reduces the magnetization deviation in the rolling direction and in the direction perpendicular to the rolling direction. However, when too much amount is added, the magnetic flux density rapidly drops, so that the addition amount is 0.11-0.42 wt%.

P: not more than 0.02% by weight

It is also known that P plays a role of lowering the iron loss by increasing the specific resistance. However, P plays a role of inhibiting grain growth by segregating into grain boundaries and it is added in an amount of 0.02% or less.

C: 0.005 wt% or less

C increases the austenite area when it is added a lot and increases the phase transformation period. However, it shows an effect of increasing the iron loss by suppressing the crystal growth of ferrite during annealing, and also forming a carbide by binding with Ti etc., When used after processing as a product, the iron loss is increased by magnetic aging, so it should be 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 harmful to the magnetic properties, and therefore it is preferable to add S as low as possible. However, when it is added less than 0.001%, it is rather disadvantageous to formation of aggregate structure and magnetic property is lowered. Therefore, it is contained in an amount of 0.001% or more, and when added in an amount exceeding 0.005%, the magnetic property is increased due to increase of fine sulfides, .

N: 0.005 wt% or less

N is an element which is detrimental to magnetism such as forming a nitride by binding strongly with Al, Ti or the like to inhibit grain growth. Therefore, it is preferable to contain N in a small amount, and in the present invention, N is limited to 0.005 wt% or less.

Ti: 0.005 wt% or less

Ti forms fine carbides and nitrides to inhibit crystal growth. As the amount of Ti is increased, the magnetization becomes poor due to increased carbides and nitrides, resulting in a dislocation of the texture. Therefore, the Ti content is limited to 0.005% or less in the present invention.

Sn or Sb: 0.05 to 0.2 wt%

The Sn and Sb are crystal grain boundaries and inhibit the diffusion of nitrogen through the grain boundaries and inhibit the formation of {111} and {112} texture which are harmful to magnetism and increase the {100} and {110} When Sn or Sb alone or in excess of 0.2% by weight is added, the grain growth is suppressed and magnetic properties are lowered and the rolling property is weakened. Therefore, at least one of Sn and Sb is added in an amount of 0.05 To 0.2% by weight.

Wherein the contents of Cu, Ni and Cr are added in an amount of 0.05 wt% or less, respectively, and the content of Zr, Mo and V is 0.01% by weight or less.

Since the Cu, Ni and Cr are inevitably added in the steel making process, Cu, Ni and Cr react with the impurity elements to form fine sulfides, carbides and nitrides, which are harmful to the magnetic properties. 0.05% by weight or less.

Further, Zr, Mo, V and the like are preferably strong carbonitride-forming elements, so that they are preferably not added, and they are contained in an amount of 0.01 wt% or less.

In addition to the above composition, the remainder include Fe and other unavoidable impurities that can be added in the steel making process.

In the present invention, Si, Al and Mn are controlled as follows.

0.7 [(Si) + [Al] - [Mn]? 1.7 and [Mn]? [Al]

(Here, [Si], [Al], and [Mn] refer to weight percent (%) of Si, Al and Mn, respectively)

When the addition amount of Si and Al is increased as the ferrite stabilizing element, there is no phase transformation in the manufacturing process and heat treatment is performed only in the single phase of ferrite. Therefore, it is difficult to improve the aggregate structure through phase transformation and Mn increases the phase transformation interval when the amount of the austenite stabilizing element is increased .

That is, when (Si] + [Al] - [Mn]) is less than 0.7, the phase transition section is too large and the phase end temperature is low. ([Si] + [Al] - [Mn]) exceeds 1.7, the phase transition region is small and the phase transformation temperature is high.

In addition, although Al lowers iron loss and reduces magnetic anisotropy, it has an effect of significantly lowering the magnetic flux density as compared to Mn, and satisfactory magnetization can be obtained by satisfying the composition formula of [Mn] ≥ [Al].

Further, the non-oriented electrical steel sheet according to the present invention can satisfy V _{110}? 0.2 and (V _{111} + V _{112} )? 0.6. (Wherein, V _{110} is the proportion of the {110} texture on the sum of the bearing, V ₍₁₁₁₎ is (111) the fraction of the aggregate structure, V _{112} to the sum of all the bearings are all bearing (112) &lt; / RTI &gt;&lt; RTI ID = 0.0 &gt;

{100}, {110}, and {111} and {112} are disadvantageous to magnetism.

The size of the crystal grains in the microstructure of the electrical steel sheet may be 20 to 120 탆.

The contents of Cu, Ni and Cr are added in an amount of 0.05 wt% or less, respectively, and the content of Zr, Mo and V is Each may be 0.01% by weight or less.

Hereinafter, a method for manufacturing a non-oriented electrical steel sheet according to another embodiment of the present invention will be described.

A method for producing a non-oriented electrical steel sheet according to the present invention is characterized in that it comprises 0.005% or less of C (not including 0%), 0.68 to 1.79 of Si, 0.14 to 0.82% of Mn, (Inclusive of 0%), S: 0.001 to 0.005%, Al: 0.11 to 0.42%, N: 0.005% or less (Si) + [Al] - [Mn], and at least one of Sn and Sb is 0.05 to 0.2%, and the balance includes Fe and other inevitably added impurities. ) ≤1.7 and [Mn] ≥ [Al], wherein [Si], [Al], and [Mn] refer to the weight percentage (%) of Si, Al and Mn, respectively ;

Heating the slab to 1,200 ° C or less and then rolling to produce a hot-rolled steel sheet;

Pickling the hot-rolled steel sheet and rolling it to 0.10 to 0.70 mm to produce a cold-rolled steel sheet; And finishing annealing the cold-rolled steel sheet at 850 to 1,100 ° C.

0.005% or less (excluding 0%), Si: 0.68-1.79%, Mn: 0.14-0.82%, P: 0.02% or less (not including 0%), S 0.001 to 0.005% of Al, 0.11 to 0.42% of N, 0.005% or less of N (not including 0%), 0.005% or less of Ti (not including 0% (Si) + [Al] - [Mn] ≤1.7 and [Mn] ≥ [Al] ([Mn]) and the balance of Fe and other inevitably added impurities. Here, the slabs satisfying the conditions of [Si], [Al], and [Mn] represent the weight percent (%) of Si, Al and Mn, respectively) are heated to 1,200 ° C or lower and rolled to produce hot rolled steel sheets.

When the heating temperature exceeds 1,200 ° C., the precipitates such as AlN and MnS present in the slab are re-precipitated at the time of hot rolling to suppress the grain growth and decrease the magnetism, so that the reheating temperature is limited to 1200 ° C. or less.

Finishing rolling in hot rolling may finish in a single phase region of ferrite having a temperature of {A ₁ (° C) - 70 ° C} or lower.

The reason why the finishing rolling is performed in the single-phase ferrite region of {A ₁ temperature (° C) - 70 ° C} or less is that when the finishing rolling is performed in the austenite / ferrite region, recrystallization is completed by the phase transformation upon cooling after hot rolling, This is because the effect of improving the texture and improving the magnetic properties by the plate annealing process is reduced.

In addition, the final reduction ratio can be reduced to 20% or less for plate shape calibration.

The heat-hot-rolled steel sheet thus prepared is rolled up at 700 ° C or less and cooled in air.

The wound hot-rolled steel sheet may further include annealing the hot-rolled steel sheet.

The hot-rolled sheet annealing is performed at 1000 to 1200 ° C for improving the magnetic properties, and can be carried out in the austenite single phase region above the A ₃ temperature (° C).

When the hot-rolled sheet annealing is performed in the austenite single-phase region above the A ₃ temperature, the effect of improving the aggregate structure due to the phase transformation can be maximized.

When the annealing temperature of the hot-rolled sheet is lower than 1000 占 폚, grain growth is insufficient and the effect of improving the aggregate structure is small. When the annealing temperature exceeds 1200 占 폚, the productivity is lowered. Surface defects become excessive.

The hot rolled sheet is pickled and cold rolled.

The cold rolling can be finally rolled to a thickness of 0.10 mm to 0.70 mm. If necessary, it can be subjected to primary cold rolling and intermediate annealing, followed by secondary cold rolling, and the final rolling reduction can be in the range of 50 to 95%.

The cold-rolled steel sheet is subjected to cold-rolled sheet annealing (finish annealing). In the step of annealing the cold-rolled sheet, the temperature of the cracking of the cold-rolled sheet during annealing (finish annealing) is 850 to 1100 ° C. If the annealing temperature of the cold rolled sheet is less than 850 캜, the growth of crystal grains is insufficient and the texture of {111} texture, which is harmful to magnetism, increases. When the temperature exceeds 1100 캜, crystal grains are excessively grown, .

The cold rolled annealed sheet may be subjected to an insulating coating treatment.

Hereinafter, a method of manufacturing a non-oriented electrical steel sheet according to the present invention will be described in detail with reference to examples. The following examples are illustrative of the present invention only and are not intended to limit the scope of the present invention.

&Lt; Example 1 >

The effect of the elemental elements and the hot rolling finishing temperature was investigated by varying the amounts of Si, Mn, Al, Sn, and Sb in the steel ingot as shown in Table 1 through vacuum melting. Each steel ingot was heated at 1180 DEG C, hot rolled to a thickness of 2.2 mm, and then wound. The hot-rolled steel sheet taken up in the air and cooled was annealed at 1130 ° C for 80 seconds, pickled, cold-rolled to a thickness of 0.35 mm, and subjected to final annealing at 990 ° C for 120 seconds.

Steel grade C Si Mn P S Al N Ti Sn Sb A ₃ A ₁ X1 0.0016 0.79 0.24 0.008 0.0016 0.19 0.0034 0.0019 0 0.06 1014 956 X2 0.0037 1.67 0.38 0.004 0.0024 0.12 0.0016 0.0037 0.06 0.03 1095 991 X3 0.0041 0.68 0.26 0.016 0.0031 0.24 0.0017 0.0044 0.02 0.07 1015 930 X4 0.0025 1.23 0.67 0.013 0.0019 0.32 0.0026 0.0008 0 0.13 1065 957 X5 0.0019 1.41 0.82 0.008 0.0036 0.35 0.0038 0.0009 0.09 0 1087 969 X6 0.0038 1.7 0.1 0.016 0.0044 0.12 0.0019 0.0017 0.16 0 1125 1025 X7 0.0023 0.66 0.12 0.011 0.0025 0.19 0.0045 0.0022 0.11 0.05 1012 954 X8 0.0034 0.91 0.4 0.01 0.0014 0.57 0.003 0.0036 0.01 0.05 1125 994 X9 0.0046 1.31 0.67 0.013 0.0035 0.42 0.0021 0.0034 0 0.07 1104 961 X10 0.0014 1.13 0.52 0.017 0.0031 0.25 0.0011 0.0028 0.07 0 1045 964 X11 0.0035 0.51 0.33 0.009 0.0027 0.46 0.0014 0.0037 0.04 0.07 1062 954 X12 0.0036 1.52 0.17 0.012 0.0033 0.12 0.0032 0.0034 0.03 0.03 1089 999

Steel grade [Si] + [Al] - [Mn] [Mn] / [Al] Finish rolling
Temperature (℃) V _{110} V _{111} + V _{112} Grain size
(탆) Iron loss W _15/50 Magnetic flux density
B ₅₀ Remarks X1 0.74 1.26 872 0.24 0.5 84 3.04 1.8 Honor X2 1.41 3.17 864 0.22 0.51 83 2.86 1.76 Honor X3 0.66 1.08 883 0.18 0.67 94 3.79 1.74 Comparative Example X4 0.88 2.09 884 0.22 0.56 72 2.91 1.77 Honor X5 0.94 2.34 883 0.23 0.54 69 3.01 1.78 Honor X6 1.72 0.83 895 0.15 0.67 88 3.84 1.73 Comparative Example X7 0.73 0.63 893 0.2 0.61 70 3.93 1.74 Comparative Example X8 1.08 0.70 885 0.16 0.68 81 3.67 1.72 Comparative Example X9 1.06 1.60 871 0.23 0.57 71 2.97 1.77 Honor X10 0.86 2.08 870 0.2 0.56 85 2.85 1.78 Honor X11 0.64 0.72 886 0.12 0.78 77 3.74 1.74 Comparative Example X12 1.47 1.42 899 0.21 0.59 83 3.07 1.79 Honor

1) _Iron loss (W _15/50 ) means the average loss (W / kg) in the rolling direction and the rolling direction perpendicular to the magnetic flux density of 1.5 Tesla at 50 Hz frequency.

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

3) In Table 1, A ₃ , A ₁ is the A ₃ temperature (° C) and A ₁ temperature (° C) according to each composition system.

EBSD and X-ray pole figure test were performed for each specimen, and the fraction of the texture was measured. The grain size was measured using the intercept method.

[Si], [Mn], [Al], [Sn], [Sb] and the Si, Al and Mn of the present invention satisfy 0.7? (Si), [Al], and [Mn] satisfy the amounts of Si, Al, and Mn added (weight%), respectively, and the composition of the [Mn] a ₁ temperature -70 ℃) in the ferrite single-phase steel grade subjected area of less than X1, X2, X4, X5, X9, X10, X12 are texture measured results, in the surface texture after cold-rolled sheet annealing (ACL) V _{110} ≥ 0.2, (V _{111} + V _{112} ) ≤0.6 and the grain size of 20 ~ 120 ㎛. As a result, the iron loss W15 / 50 and the magnetic flux density B50 were excellent.

On the other hand, X3 is Si, Al, Mn, each administration ranges are satisfied, but the formula 0.7≤ ([Si] + [Al ] - [Mn]) was not satisfied even ≤1.7 finish rolling temperature during hot rolling (A ₁ It was not satisfied with the temperature -70 ℃) under the following conditions texture measurement result _{V {110} ≥0.2, (V} {111} + V {112}) failure to meet all of ≤0.6 a result the iron loss and magnetic flux density inferior Respectively.

X6 satisfied the control range of Si, Al and Mn, respectively, but did not satisfy the composition formula 0.7? ([Si] + [Al] - [Mn])? 1.7 and [Mn]? [Al] V _{110} ≥0.2 (V _{111} + V _{112} ) ≤0.6. As a result, iron loss and magnetic flux density were inferior.

X7 satisfied the control range of Si, Al and Mn respectively but did not satisfy the composition formula [Mn] ≥ [Al] and the finish rolling temperature during hot rolling satisfies the condition of {A1 temperature (° C.) - 70 ° C. (V _{111} + V _{112} ) ≤0.6. As a result, core loss and magnetic flux density were inferior.

X8 is Si and Mn was not satisfied with the Al a management range, but satisfies the management range the composition formula [Mn] ≥ was [Al] also does not satisfy the texture measurement result _{V {110} ≥0.2 (V {} 111} + V _{112} ) ≤0.6. As a result, iron loss and magnetic flux density are inferior.

X11 satisfied the control range of Si, Al and Mn, respectively, but did not satisfy the above composition formula 0.7? ([Si] + [Al] - [Mn])? 1.7 and [Mn]? [Al] The rolling finish temperature of the finish was not satisfactory under the condition of {A ₁ temperature (° C) - 70 ° C} or less. The result of the texture measurement showed that all of V _{110} ≥0.2 (V _{111} + V _{112} ) ≤0.6 As a result, iron loss and magnetic flux density were inferior.

&Lt; Example 2 >

A steel ingot was prepared as shown in Table 3 through vacuum melting. The effects of hot rolling finishing temperature, annealing of hot - rolled sheet and annealing temperature of cold - rolled sheet on aggregate texture, grain size and magnetism were investigated. Each steel ingot was heated at 1150 DEG C, hot rolled to a thickness of 2.4 mm, and then wound. The hot-rolled steel sheet obtained by winding and cooling in air was annealed at a temperature shown in Table 4 for 75 seconds, pickled, cold-rolled to a thickness of 0.35 mm, and finally annealed at 800 to 1150 ° C for 100 seconds.

Steel grade C Si Mn P S Al N Ti Sn Sb A ₃ A ₁ Y1 0.0027 1.06 0.18 0.008 0.0016 0.17 0.0034 0.0019 0.06 0.03 1041 970 Y2 0.0034 1.79 0.34 0.0019 0.0038 0.16 0.0021 0.0008 0.06 0 1132 1019 Y3 0.0017 1.52 0.17 0.0015 0.0026 0.11 0.0023 0.0006 0.02 0.07 1088 1016 Y4 0.0041 1.34 0.38 0.0013 0.0021 0.32 0.0037 0.0011 0.09 0.1 1104 985 Y5 0.0035 0.95 0.64 0.0008 0.0034 0.46 0.0019 0.0037 0.12 0.02 1075 950 Y6 0.0022 0.94 0.49 0.0018 0.0036 0.41 0.0014 0.0022 0 0.1 1073 971 Y7 0.0015 0.85 0.22 0.007 0.0044 0.2 0.0016 0.0026 0 0.15 1025 966 Y8 0.0013 1.02 0.25 0.009 0.0015 0.15 0.0037 0.0035 0.04 0.06 1026 969 Y9 0.0027 1.16 0.53 0.006 0.0022 0.43 0.0045 0.003 0.08 0 1101 984 Y10 0.0033 1.33 0.14 0.01 0.0027 0.13 0.0042 0.002 0.07 0 1067 987 Y11 0.0025 1.41 0.29 0.016 0.0033 0.22 0.0024 0.0046 0.05 0.05 1093 1001

Steel grade [Si] + [Al] - [Mn] [Mn] /
[Al] Wrap-up
Rolling
Temperature (℃) Hot-rolled plate
Annealing temperature (캜) Cold rolled plate
Annealing temperature (캜) V _{110} V _{111} + V _{112} Grain size
(탆) Iron loss W _15/50 Magnetic flux density
B ₅₀ Remarks Y1 1.05 1.06 888 1070 990 0.21 0.54 68 3.04 1.8 Honor Y2 1.61 2.13 879 1140 1050 0.23 0.49 88 2.84 1.78 Honor Y3 1.46 1.55 885 1100 1030 0.22 0.48 70 2.88 1.79 Honor Y4 1.28 1.19 877 1060 1000 0.18 0.59 72 3.75 1.75 Comparative Example Y5 0.77 1.39 886 1090 840 0.15 0.74 23 3.59 1.74 Comparative Example Y6 0.86 1.20 891 1090 880 0.2 0.52 42 2.9 1.78 Honor Y7 0.83 1.10 892 1040 960 0.24 0.55 55 2.95 1.79 Honor Y8 0.92 1.67 880 1030 920 0.25 0.56 53 3.02 1.79 Honor Y9 1.06 1.23 872 1080 830 0.14 0.72 18 3.38 1.73 Comparative Example Y10 1.32 1.08 883 1080 1020 0.24 0.54 64 2.82 1.78 Honor Y11 1.34 1.32 892 1040 1120 0.17 0.65 125 3.41 1.74 Comparative Example

1) _Iron loss (W _15/50 ) means the average loss (W / kg) in the rolling direction and the rolling direction perpendicular to the magnetic flux density of 1.5 Tesla at 50 Hz frequency.

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

3) In Table 1, A ₃ , A ₁ is the A ₃ temperature (° C) and A ₁ temperature (° C) according to each composition system.

[Si] + [Al] - [Si], [Mn], [Al], [Sn] and [Sb] (Si), [Al], and [Mn] satisfy the addition amounts (% by weight) of Si, Al, and Mn, respectively, and the hot- A1 temperature (℃) - was performed in the ferrite single phase region of 70 ℃} than a _3-described hot-rolled sheet annealing at a temperature of austenite single phase region, and annealing the cold-rolled sheet at a temperature of 850 ~ 1100 ℃ grades Y1, Y2, Y3 , Y6, Y7, Y8 and Y10 satisfy V _{110} ≥0.2 and (V _{111} + V _{112} ) ≤0.6 in the surface texture after cold rolled sheet annealing (ACL) be satisfied for 20 ~ 120㎛ as a result the iron loss W _15/50 and magnetic flux density B ₅₀ is shown as excellent.

On the other hand, Y4 is a hot-rolled sheet annealing (APL) temperature A ₃ was not satisfy the condition for performing the hot-rolled sheet annealing at a temperature of austenite single phase region failure to satisfy the texture measurement result V _{110} ≥0.2 As a result the iron loss And magnetic flux densities were low.

Y5 is an amount of addition of [Si], [Mn], [Al], [Sn], and [Sb] ] ≥ formula (wherein the [Si], [Al], [Mn] is Si, Al, the addition amount of Mn (wt%) each) {a ₁ temperature (℃) the hot finish rolling, but satisfies the [Al] - 70 (ACL) temperature was too low to satisfy the condition of 850 ~ 1100 ℃, and as a result of the texture measurement, V _{110} ≥0.2, (V _{111} + V _{112} ) _≤0.6. As a result, the iron loss W _15/50 and the magnetic flux density B ₅₀ were inferior.

On the other hand, when Y9 is at least one element selected from the group consisting of [Si], [Mn], [Al], [Sn], [Sb] (A1) (Al) and Mn (Mn) satisfy the composition formula (Si, Al and Mn added amounts of Si, Al and Mn ℃} but performed in the ferrite single-phase region below a ₃ was not satisfied with the conditions that annealing a hot-rolled sheet annealing conditions and cold-rolled sheet to a temperature above the austenite single-phase region at a temperature of 850 ~ 1100 ℃ texture measurement result V _{{110 }} ≥0.2, (V _{111} + V _{112} ) ≤0.6, and the grain size was too small because the cold-rolled sheet annealing temperature was too low. As a result, the iron loss W _15/50 and the magnetic flux density B ₅₀ were _dull appear.

In addition, Y11 is preferably selected from the group consisting of Si, Mn, Al, Sn, Sb and Si, Al and Mn in the range of 0.7? (Si) + [Al] - [Mn] 1.7 and [Mn] ≥ [Al] formula (wherein the [Si], [Al], [Mn] is Si, Al, the addition amount (% by weight) of Mn, respectively) for satisfying the hot finish rolling {a ₁ temperature ( ° C) - 70 ° C}. However, the conditions for annealing the hot-rolled sheet at the austenite single-phase region above the A ₃ temperature and annealing the cold-rolled sheet at the temperature of 850 to 1100 ° C were not satisfied, results _{V {110} ≥0.2, (V} {111} + V {112}) was not satisfied ≤0.6 cold-rolled sheet annealing temperature was too high appeared that the grain size of coarse result the iron loss W _15/50 and the magnetic flux Density B ₅₀ was inferior.

While the present invention has been described in connection with certain exemplary embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims (2)

0.005% or less (excluding 0%), Si: 0.68-1.79%, Mn: 0.14-0.82%, P: 0.02% or less (not including 0%), S 0.001 to 0.005% Al, 0.11 to 0.42% N, 0.005% or less (not including 0%) and Ti: 0.005% or less (not including 0%
Sn alone, Sb alone, or 0.05 to 0.2% by total of Sn and Sb, the balance including Fe and other inevitably added impurities,
The Si, Al, and Mn are
0.7 [(Si) + [Al] - [Mn]? 1.7 and [Mn]? [Al]
(Here, [Si], [Al], and [Mn] refer to weight percent (%) of Si, Al and Mn, respectively)
Providing a slab that satisfies &lt; RTI ID = 0.0 &gt;
Heating the slab to 1,200 ° C or less and then rolling to produce a hot-rolled steel sheet;
Annealing the hot-rolled steel sheet at a temperature of 1,000 to 1,200 ° C;
Pickling the hot-rolled steel sheet and rolling it to 0.10 to 0.70 mm to produce a cold-rolled steel sheet; And
And finishing and annealing the cold-rolled steel sheet at 850 to 1,100 ° C,
The size of the crystal grains in the microstructure of the electric steel sheet after finishing annealing is 20 to 120 탆,
In the step of producing the hot-rolled steel sheet, the finish rolling is finished in a single-phase ferrite phase having a temperature of (A ₁ temperature (° C) - 70 ° C}
The hot-rolled sheet annealing is carried out in a single-phase austenite region above the A ₃ temperature (캜)
Wherein the electric steel sheet after finishing annealing satisfies V _{110}? 0.2 and satisfies (V _{111} + V _{112} )? 0.6.
Where V _{110} is the {110} texture fraction of the sum of all orientations, V _{111} is the fraction of {111} texture relative to the sum of all orientations, and V _{112} Means the fraction of {112} aggregated tissue for the sum) The method according to claim 1,
Wherein the inevitably added impurities include Cu, Ni, Cr, Zr, Mo, and V, and the contents of Cu, Ni, and Cr are each 0.05 wt% or less (do not include 0 wt% Wherein the contents of Zr, Mo and V are respectively 0.01% by weight or less (not including 0% by weight).