KR101665951B1 - Non-oriented electrical steel sheets and method for manufacturing the same - Google Patents

Abstract

A non-oriented electrical steel sheet and a manufacturing method thereof are disclosed. The non-oriented electrical steel sheet according to the present invention contains, by weight%, 0.005% or less of C, 0.86 to 1.75% of Si, 0.01 to 0.08% of Mn, 0.005 to 0.019% of P, , 0.001 to 0.005% of S, 0.005% or less of Al (not including 0%), 0.005% or less of N (not including 0%) and 0.005% or less of Ti , Sn alone, Sb alone, or 0.05 to 0.2% Sn and Sb total, the remainder including Fe and other inevitably added impurities,
The Si and the Mn satisfy 0.7? ([Si] - [Mn])? 1.7 where [Si] and [Mn] represent the weight percent (%) of Si and Mn, respectively.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention 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 component system of the steel sheet.

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.

An object of the present invention is to provide a non-oriented electrical steel sheet having a low iron loss and excellent magnetic properties by optimally controlling components of Si, Mn, Al and P among alloying elements of steel, and a manufacturing method thereof.

The non-oriented electrical steel sheet according to one embodiment of the present invention is characterized by containing, by weight%, 0.005% or less of C, 0.86 to 1.75% of Si, 0.01 to 0.08% of Mn, 0.005 to 0.019%, S: 0.001 to 0.005%, Al: 0.005% or less (not including 0%), N: 0.005% or less (not including 0%), and Ti: 0.005% (Si), Sb alone, or 0.05 to 0.2% Sn and Sb, and the remainder includes Fe and other inevitably added impurities, wherein Si and Mn satisfy 0.7? ([Si ] - [Mn]) < / = 1.7 wherein {Si} and [Mn] represent the weight percentage (%) of Si and Mn, respectively.

The non-oriented electrical steel sheet may satisfy V _{110}? 0.2. (Where V _{110} is the fraction of {110} texture of the sum of all orientations)

The non-oriented electrical steel sheet may satisfy (V _{100} + V _{110} ) / (V _{111} + V _{112} )? Where V _{100} is the fraction of {100} texture of the sum of all orientations, V _{110} is the fraction of {110} texture of the sum of all orientations, V _{111} , And V _{112} is the fraction of the {112} texture of the sum of all the orientations)

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.

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

A method of manufacturing a non-oriented electrical steel sheet according to an embodiment of the present invention includes the steps of: providing a steel sheet containing 0.005% or less of C (not including 0%), 0.86 to 1.75% of Si, 0.01 to 0.08% , 0.005 to 0.019% of P, 0.001 to 0.005% of S, 0.005% or less of Al (not including 0%), 0.005% or less of N (not including 0%) and 0.005% or less of Ti %), Sn, Sb alone, or 0.05 to 0.2% Sn and Sb, and the remainder includes Fe and other inevitably added impurities, wherein Si and Mn satisfy the relationship of 0.7 < ([Si] - [Mn]) < / = 1.7, wherein [Si] and [Mn] each represent a weight percentage (%) of Si and Mn); 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.

In the step of manufacturing the hot-rolled steel sheet, the finish rolling may be characterized by ending in a ferrite single-phase region of {A ₁ temperature (° C) - 40 ° C} or lower.

The hot-rolled steel sheet may further include a step of annealing the hot-rolled steel sheet at 1,000 to 1,200 ° C, and the hot-rolled sheet annealing may be performed in a single-phase austenite region of A ₃ temperature or more.

The electrical steel sheet having completed the finish annealing can satisfy V _{110}? 0.2. (Where V _{110} is the fraction of {110} texture of the sum of all orientations)

The electrical steel sheet after completion of the finish annealing can satisfy (V _{100} + V _{110} ) / (V _{111} + V _{112} )? 0.5. Where V _{100} is the fraction of the texture for the sum of all orientations of {100}, V _{110} is the fraction of {110} texture for the sum of all orientations, V _{111} , And V _{112} is the fraction of the {112} texture of the sum of all the orientations)

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.

The size of the crystal grains in the microstructure of the electric steel sheet after finishing annealing may be 20 to 120 탆.

The non-oriented electrical steel sheet according to the present invention can optimally control the component system of Si, Mn, Al and P to produce a non-oriented electrical steel sheet having excellent iron loss reduction ratio and improved magnetism remarkably.

Further, the non-oriented electrical steel sheet according to the present invention can be controlled in the range of 0.7? ([Si] - [Mn])? 1.7 so as to undergo a phase transformation during the heat treatment process, thereby improving the magnetism by increasing the texture favorable to magnetism.

In addition, the non-oriented electrical steel sheet according to the present invention the finish rolling - and not to be carried {A ₁ temperature (℃) 40 ℃} in the ferrite single-phase region hereinafter, the hot-rolled sheet annealing is magnetic by carrying out in the austenite single-phase region or more A ₃ temperature It is possible to improve the magnetism by increasing the favorable aggregate structure.

The addition amount of Si is less than 2 wt%, the amount of Mn is less than 0.08 wt%, the amount of Al is less than 0.005 wt%, and the amount of P is less than 0.02 wt% A non-oriented electrical steel sheet excellent in magnetic flux density and improved in iron loss, and a method of manufacturing the same 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 be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with 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.

0.005 to 0.019% of P, 0.001 to 0.005% of S, 0.001 to 0.005% of Sn, 0.30 to 0.08% of Mn, 0.01 to 0.08% of Mn, : Not more than 0.005% (not including 0%), N: not more than 0.005% (not including 0%) and Ti: not more than 0.005% (not including 0%), Sn alone, Sb alone, Or 0.05 to 0.2% by total of Sn and Sb, and the remainder comprises Fe and other inevitably added impurities,

The Si and Mn

0.7? ([Si] - [Mn])? 1.7

(Where, [Si] and [Mn] mean the percentages by weight of Si and Mn, respectively)

.

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

Si: 0.86 to 1.75 wt%

The Si is a main element added to increase the resistivity of the steel to lower the vortex loss during iron loss. However, as the addition amount increases, the element decreases the magnetic flux density. It is difficult to obtain the characteristics of the high magnetic flux density as the addition amount increases. When it is added, it is preferable to limit the addition amount to 1.75% by weight or less because the ferrite structure hardly includes phase transformation in the manufacturing process and is heat-treated only in the ferrite structure to improve the texture.

Mn: 0.01 to 0.08 wt%

The Mn is effective not only to increase the resistivity but also to lower the iron loss by addition of Si and Al. However, it is preferable not to add Mn because MnS or MnCuS such as MnS and MnCuS are formed and the magnetism is weakened.

However, it is limited to 0.08% or less in consideration of the amount that is inevitably added in the steelmaking process due to alloying iron and impurities.

Al: 0.005 wt% or less

The Al is added to lower the iron loss as a main element for increasing the specific resistance, but it also serves to decrease the saturation magnetic flux density when added and may also cause the magnetism to be dislocated by forming AlN or the like. Also, it is preferable that Al is not added when the addition amount is increased as in the case of Si, because it affects the ferrite region to enlarge to reduce the phase transformation period.

However, the addition amount thereof is limited to 0.005% or less in consideration of the amount that is inevitably added in the steelmaking process due to alloying iron, impurities and the like.

P: 0.005 to 0.019 wt%

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 suppressing grain growth by segregating in grain boundaries, and it is added in an amount of 0.019 wt% 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 wt%

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 in an amount of less than 0.001% by weight, it is rather disadvantageous to formation of aggregate structure, so that the magnetic property is deteriorated. Therefore, it is contained in an amount of 0.001% by weight or more and when it is added in an amount exceeding 0.005% by weight, To 0.005% by weight.

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, suppressing the diffusion of nitrogen through grain boundaries, suppressing the formation of {111} texture which is harmful to magnetism, and increasing {100} and {110} When Sn or Sb alone or in excess of 0.2% by weight is added, crystal grain growth is suppressed and magnetic properties are lowered and the rolling property is disadvantageously decreased. Therefore, at least one of Sn and Sb is added in an amount of 0.05 to 0.2% Lt; / RTI >

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 and Mn are controlled as follows.

0.7? ([Si] - [Mn])? 1.7

(Where, [Si] and [Mn] mean the percentages by weight of Si and Mn, respectively)

Si is an element stabilizing ferrite. When Si is added 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 texture through phase transformation. Mn increases the phase transformation interval when the amount of the austenite stabilizing element is increased.

That is, when ([Si] - [Mn]) is less than 0.7, there is a problem that the phase transition section is too large and the phase transformation end temperature is low. ([Si] - [Mn]) exceeds 1.7, the phase transition section is small and the phase transformation temperature is high, so that it is difficult to pass the phase transformation section during the heat treatment.

Further, the non-oriented electrical steel sheet according to the present invention can satisfy (V _{100} + V _{110} ) / (V _{111} + V _{112} )? Where V _{100} is the fraction of {100} texture of the sum of all orientations, V _{110} is the fraction of {110} texture of the sum of all orientations, V _{111} , And V _{112} is the fraction of the {112} texture of the sum of all the 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 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 a method for producing a non-oriented electrical steel sheet, which comprises 0.005% or less of C, 0.86 to 1.75% of Si, 0.01 to 0.08% of Mn, 0.005 to 0.019%, S: 0.001 to 0.005%, Al: 0.005% or less (not including 0%), N: 0.005% or less (not including 0%), and Ti: 0.005% ), Sn alone, Sb alone, or 0.05 to 0.2% Sn and Sb in total, the balance including Fe and other inevitably added impurities,

Wherein Si and Mn satisfy 0.7? ([Si] - [Mn])? 1.7 (where [Si] and [Mn] mean the percentages by weight of Si and Mn, respectively) step;

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 to 0.019% of P, 0.001 to 0.005% of S, 0.001 to 0.005% of Sn, 0.30 to 0.08% of Mn, 0.01 to 0.08% of Mn, : Not more than 0.005% (not including 0%), N: not more than 0.005% (not including 0%) and Ti: not more than 0.005% (not including 0%), Sn alone, Sb alone, Or Sn and Sb, and the remainder comprises Fe and other inevitably added impurities, wherein Si and Mn satisfy 0.7? ([Si] - [Mn])? ] And [Mn] respectively denote percentages by weight of Si and Mn) are heated to 1,200 ° C or lower and then rolled to produce a hot-rolled steel sheet.

When the heating temperature exceeds 1,200 ° C., precipitates such as AlN and MnS existing in the slab are reused and then precipitated by the fine rolling during hot rolling to suppress grain growth and decrease magnetism, so that the reheating temperature is limited to 1,200 ° C. or less.

Finishing rolling in hot rolling can be finished in a single phase region of ferrite having a temperature of {A ₁ (° C) - 40 ° C} or lower.

The reason why the finish rolling is performed in a single-phase ferrite region of {A ₁ temperature (占 폚 - 40 占 폚) or less is that when the finish 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.

≪ 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 1150 占 폚, hot rolled to a thickness of 2.5 mm, and then wound. The hot-rolled steel sheet wound and cooled in air was annealed at 1120 占 폚 for 90 seconds, pickled, cold-rolled at a thickness of 0.35 mm, and finally annealed at 990 占 폚 for 100 seconds.

Steel grade C Si Mn P S Al N Ti Sn Sb A ₃ (占 폚) A ₁ (° C) X1 0.0037 0.62 0.02 0.015 0.0019 0.005 0.0016 0.0034 0.04 0.02 961 917 X2 0.0045 0.75 0.04 0.011 0.0049 0.001 0.0027 0.0012 0.09 0 968 915 X3 0.0035 1.67 0.01 0.019 0.0027 0.003 0.0021 0.0027 0.12 0.06 1093 1015 X4 0.0038 1.23 0.08 0.007 0.0013 0.002 0.0039 0.0009 0.01 0.08 1020 957 X5 0.0013 1.75 0.07 0.006 0.0037 0.001 0.0044 0.0034 0.06 0.09 1103 1039 X6 0.0022 1.11 0.03 0.008 0.0031 0.002 0.0017 0.004 0 0.12 1010 968 X7 0.0033 1.39 0.05 0.016 0.0042 0.005 0.0011 0.0015 0.01 0.01 1046 982 X8 0.0048 0.82 0.08 0.013 0.0037 0.003 0.0029 0.0035 0.02 0.03 972 913 X9 0.0015 1.82 0.07 0.004 0.0026 0.002 0.0023 0.0029 0.05 0 1115 1046 X10 0.0026 1.25 0.09 0.005 0.0016 0.008 0.003 0.0014 0 0.07 1025 971 X11 0.0027 1.24 0.03 0.017 0.0022 0.003 0.0016 0.0023 0 0.09 1027 975 X12 0.0037 0.86 0.06 0.018 0.0037 0.002 0.0025 0.0037 0.06 0.03 978 929 X13 0.0023 1.17 0.06 0.006 0.0015 0.004 0.0036 0.0046 0.08 0.04 1016 969

Steel grade [Si] - [Mn] Finish rolling
Temperature (℃) After APL, V _{110} V _{110} after ACL (V _{100} + V _{110} ) /
(V _{111} + V _{112} ) Grain size
(탆) Magnetic flux density
B ₅₀ Remarks X1 0.6 889 0.19 0.16 0.39 64 1.76 Comparative Example X2 0.71 877 0.18 0.19 0.44 55 1.74 Comparative Example X3 1.66 895 0.21 0.24 0.51 67 1.79 Honor X4 1.15 866 0.24 0.23 0.64 86 1.81 Honor X5 1.68 893 0.2 0.21 0.53 51 1.79 Honor X6 1.08 868 0.23 0.26 0.57 59 1.81 Honor X7 1.34 871 0.21 0.18 0.47 78 1.75 Comparative Example X8 0.74 880 0.17 0.19 0.4 60 1.76 Comparative Example X9 1.75 901 0.21 0.19 0.48 75 1.73 Comparative Example X10 1.16 888 0.17 0.14 0.38 77 1.76 Comparative Example X11 1.21 875 0.24 0.25 0.61 81 1.8 Honor X12 0.8 879 0.2 0.22 0.55 90 1.82 Honor X13 1.11 906 0.22 0.21 0.56 77 1.8 Honor

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

2) 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.

As shown in Table 2, the composition formula of [Si], [Mn], [Al], [Sn], [Sb] and 0.7 ], [Mn] is Si, the added amount of Mn (wt%)) to meet and the hot finish rolling {a ₁ temperature (℃) - 40 ℃} each steel type conducted in the ferrite single-phase region below X3, X4, X5, X6 , X11, X12, and X13 were V _{110} ≥0.2 in cross-sectional texture after hot-rolled sheet annealing (APL) and after cold-rolled sheet annealing (ACL) (V _{100} + V _{110} ) / (V _{111} + V _{112} ) ≥0.5 and a grain size of 20 to 120 탆. As a result, the magnetic flux density B ₅₀ was very high.

On the other hand, X1 satisfied the control range of Si and Mn, but did not satisfy the above composition formula, and the finish rolling temperature during hot rolling did not satisfy the condition {A1 temperature (° C) - 40 ° C} (V _{110} + V _{110} ) / (V _{111} + V _{112} ) ≥0.5 after the APL and ACL after V _{110} appear.

X2 and X8 satisfied the composition and the composition formula but the finish rolling temperature did not satisfy the condition of {A ₁ temperature (℃) - 40 ℃} or less during hot rolling, and V _{110} ≥0.2 and ACL (V _{100} + V _{110} ) / (V _{111} + V _{112} ) ≥0.5, resulting in a low magnetic flux density.

X7 satisfied the conditions of Si and Mn addition and Sn and Sb additions. However, after the APL, V _{110} ≥0.2 was satisfied, but V _{110} ≥0.2 and (V _{{ 100}} + V _{110} ) / (V _{111} + V _{112} ) ≥0.5. As a result, the magnetic flux density was low.

X9 was satisfied with Si and Mn but satisfied V _{110} ≥0.2 after APL, but V _{110} ≥0.2 and (V _{100} + V _{110} ) / (V _{111} + V _{112} ) ≥0.5. As a result, the magnetic flux density was low.

X10 was not the Mn and Al satisfies the content range as a result after APL after and after ACL V _{110} ≥0.2 and _{ACL (V {100} + V} {110}) / (V {111} + V {112 _} ) ≥0.5 and the magnetic flux density was low.

≪ 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 1170 DEG C, hot rolled to a thickness of 2.6 mm, and then wound. The hot-rolled steel sheet wound and cooled in air was annealed at 950 to 1100 ° C for 80 seconds, pickled and cold-rolled to a thickness of 0.35 mm, and subjected to final annealing at 800 to 1150 ° C for 110 seconds.

Steel grade C Si Mn P S Al N Ti Sn Sb A3 (占 폚) A1 (占 폚) Y1 0.0018 1.56 0.04 0.016 0.0037 0.002 0.0034 0.0009 0 0.06 1073 1016 Y2 0.0038 0.81 0.06 0.004 0.0044 0.001 0.0018 0.0046 0.04 0.04 973 924 Y3 0.0049 1.38 0.01 0.018 0.0011 0.003 0.0016 0.0037 0.03 0.04 1046 969 Y4 0.0037 1.12 0.07 0.011 0.002 0.002 0.0037 0.0035 0.1 0.02 1007 949 Y5 0.0022 0.95 0.05 0.005 0.0035 0.005 0.0025 0.0019 0 0.11 991 953 Y6 0.0026 1.23 0.06 0.009 0.0021 0.004 0.0016 0.002 0.09 0 1023 972 Y7 0.0019 1.64 0.02 0.013 0.0039 0.005 0.0019 0.0016 0.13 0.02 1089 1027 Y8 0.0038 0.79 0.04 0.015 0.0018 0.003 0.0033 0.0011 0.05 0.02 973 925 Y9 0.0033 1.13 0.08 0.009 0.0013 0.002 0.0046 0.0015 0.08 0 1007 953 Y10 0.0034 0.89 0.04 0.01 0.0024 0.002 0.0015 0.004 0.03 0.03 984 936 Y11 0.0026 1.33 0.05 0.017 0.0031 0.003 0.0034 0.0022 0 0.05 1037 983 Y12 0.0035 1.18 0.03 0.013 0.0037 0.004 0.0029 0.0016 0.04 0.05 1019 962

Steel grade [Si] - [Mn] Wrap-up
Rolling
Temperature (℃) Hot-rolled plate
Annealing temperature (캜) Cold rolled plate
Annealing temperature (캜) After APL
V _{110} After ACL
V _{110} V _{100} + V _{110} ) /
(V _{111} + V _{112} ) Grain size
(탆) Magnetic flux density
B50 Remarks Y1 1.52 867 1100 900 0.24 0.21 0.54 46 1.79 Honor Y2 0.75 890 960 990 0.14 0.17 0.41 84 1.76 Comparative Example Y3 1.37 869 1050 1030 0.23 0.23 0.56 94 1.8 Honor Y4 1.05 881 1040 950 0.21 0.21 0.51 73 1.82 Honor Y5 0.9 891 1030 930 0.22 0.21 0.53 61 1.82 Honor Y6 1.17 903 1070 1010 0.2 0.2 0.52 88 1.81 Honor Y7 1.62 885 1020 980 0.16 0.18 0.43 76 1.74 Comparative Example Y8 0.75 888 1050 830 0.21 0.18 0.48 38 1.76 Comparative Example Y9 1.05 873 1080 1000 0.23 0.21 0.54 80 1.81 Honor Y10 0.85 868 1080 1060 0.22 0.24 0.57 95 1.82 Honor Y11 1.28 872 1010 840 0.17 0.14 0.39 42 1.75 Comparative Example Y12 1.15 860 1070 1120 0.23 0.15 0.45 132 1.75 Comparative Example

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

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

As shown in Table 4, the composition formula of [Si], [Mn], [Al], [Sn], [Sb] and 0.7 ≤ [Si] - [Mn] (APL) and (Mn) were performed in a ferrite single phase region satisfying the hot rolling (A ₁ temperature (° C) - 40 ° C} or less and the hot rolled annealing Y1, Y3, Y4, Y5, Y6, Y9, and Y10, which satisfied the cold rolled sheet annealing (ACL) condition, showed the cross-sectional texture after annealing of hot-rolled sheet (APL) It was in all tissues satisfies V _{110} ≥0.2, after ACL on the surface texture _{(V {100} + V {} 110}) / (V {111} + V {112}) grain size, and also satisfies the ≥0.5 20 to 120 탆, and as a result, the magnetic flux density B50 was very high.

On the other hand, Y2 satisfies the condition that the composition satisfies the composition and the annealing temperature of the cold-rolled steel sheet but the finish rolling temperature (A1 temperature -40 ° C) or less during hot rolling and APL annealing condition in the austenite single- It was not texture measurements APL after ACL and after V _{110} ≥0.2 and ACL then _{(V {100} + V {} 110}) / (V {111} + V {112}) was not satisfied with the ≥0.5 As a result, the magnetic flux density was low.

Y7 satisfied the composition, the above composition formula, the hot rolling finish temperature and ACL annealing condition, but did not satisfy the APL annealing condition in the austenite single phase region above A3 temperature. As a result of the aggregate structure measurement, V _{110} 0.2 and ACL did not satisfy (V _{100} + V _{110} ) / (V _{111} + V _{112} ) ≥0.5, resulting in low magnetic flux density.

On the other hand, Y8 satisfied the composition and composition formula and satisfied the APL annealing condition but did not satisfy the hot rolling finishing temperature and the ACL annealing condition was too low. As a result of collective structure measurement, V _{110} ≥0.2 and (V _{{100 }} + V _{110} ) / (V _{111} + V _{112} ) ≥0.5. As a result, the magnetic flux density was low.

Y11 satisfied the composition and the hot rolling finish temperature condition, but did not satisfy APL and ACL annealing conditions. As a result, V11 ₌ 0.2 after ACL and after ACL, and V ₍₁₀₀₎ + V _{110} ) / (V _{111} + V _{112} ) ≥0.5. As a result, the magnetic flux density was low.

In addition, Y12 satisfied V _{110} ≥0.2 and (V _{100} + V _{110} ) after ACL, because the composition, the composition formula, the hot rolling finish temperature and the APL annealing condition were satisfied, / (V _{111} + V _{112} ) ≥0.5 and the grain size was too large as 132 ㎛ and the magnetic flux density was low as a result.

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 to 0.019% of P, 0.001 to 0.005% of S, 0.001 to 0.005% of Sn, 0.30 to 0.08% of Mn, 0.01 to 0.08% of Mn, : 0.005% or less (does not include 0%), N: 0.005% or less (does not include 0%) and Ti: 0.005% or less (does not include 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 and Mn
0.7? ([Si] - [Mn])? 1.7
(Where, [Si] and [Mn] mean the percentages by weight of Si and Mn, respectively)
Providing a slab that satisfies < RTI ID = 0.0 >
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,
In the step of producing the hot-rolled steel sheet, the finish rolling is finished in a single-phase ferrite phase of {A ₁ temperature (° C) - 40 ° C}
The hot-rolled sheet annealing is carried out in a single-phase austenite region above the A ₃ temperature (캜)
The electrical steel sheet after completion of the finish annealing satisfies V _{110} ≥0.2 and (V _{100} + V _{110} ) ≥ (0.5) x (V _{111} + V _{112}
Wherein the grain size of the grain in the microstructure of the steel sheet subjected to finish annealing is 20 to 120 占 퐉 and the magnetic flux density (B50) is 1.79 to 1.82 T.
Where V _{100} is the fraction of {100} texture of the sum of all orientations, V _{110} is the fraction of {110} texture of the sum of all orientations, V _{111} , And V _{112} is the fraction of the {112} texture of the sum of all the orientations) 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).