Technical field
[0001]
　The present invention includes a high-frequency iron loss is low non-oriented electrical steel sheet, and to a manufacturing method for producing the non-oriented electrical steel sheet with high productivity. More particularly, the present invention relates to a high energy efficiency and small dimensions and high Suitable non-oriented electrical steel sheet iron core material for electrical equipment in power and is required and a manufacturing method thereof. Such electrical equipment, for example, air conditioner compressor motor, hybrid automobiles, electric automobiles, and a drive motor mounted on a fuel cell vehicle, and small generators and the like to be mounted on a motorcycle and household cogeneration system.
　The present application, to March 17, 2015, claiming priority based on Japanese Patent Application No. 2015-053095, filed in Japan, the contents of which are incorporated here.
Background technique
[0002]
　Recently, in order to solve global environmental issues, in a more compact, more output is high, more energy efficiency is required to have high electrical device. Therefore, the non-oriented electrical steel sheet used for the iron core of electrical equipment (steel sheet), both the low iron loss and high magnetic flux density is strongly demanded.
[0003]
　In particular, in the driving motor of a hybrid vehicle or an electric vehicle, in order to compensate for the torque reduction accompanying the miniaturization, thereby increasing the rotational speed of the drive motor. Increasing the rotational speed, the iron loss increases the frequency of the magnetic field applied to the steel sheet is increased. Therefore, the steel sheet, it is required to reduce the iron loss at high frequency (high-frequency iron loss). As means for reducing the high frequency iron loss, the thickness reduction of the increase of the specific resistance, the reduction of impurity elements have been employed. For example, Patent Documents 1-5, by increasing the content of alloying elements such as Si and Al in the steel sheet, thereby increasing the specific resistance of the steel sheet.
[0004]
　However, when the Si and Al added in a large amount in the steel, the productivity and yield become cracked or broken is likely to occur at the time of production of the steel sheet is lowered. To prevent a reduction in the productivity and yield, it is effective to reduce the amount of Si and Al in the steel lowers the hardness of the steel. Meanwhile, in order to further reduce the iron loss, it is necessary to increase the resistivity by increasing the amount of Si and Al in the steel. Al is on the increase in the specific resistance per unit mass effect is almost equal to Si, the effect of Al is on the rise in hardness per unit mass is about 1/3 ~ 1/2 of Si. Therefore, Al has been used as an element effective for lowering the iron loss without deteriorating as much as possible productivity. That is, by further increasing the Al content in the steel, and further reduce the iron loss. Thus, in order to increase the specific resistance, so the content of alloying elements are expected to be further increased, it was necessary to further improve productivity.
[0005]
　For example, Patent Document 1, by mass%, Si: 1.5% ~ 3.5%, Al: contains 0.6% to 3.0%, and (Al / (Si + Al)) 0.3 method of controlling the average grain size and Vickers hardness of the hot-rolled annealed sheet produced from the steel satisfying 0.5 is disclosed. In Patent Document 1, rupture-resistance of the hot-rolled annealed sheet is improved by this method, it is disclosed that can provide non-oriented electrical steel sheet high-frequency iron loss is low without sacrificing productivity . That is, the method disclosed in Patent Document 1 is different from the method disclosed in Patent Documents 2 to 5, and adjusting the ratio of the Al content to the total of the Si content and Al content.
[0006]
　However, the high-frequency iron loss is increased when the ratio of the Al content is above a certain value. This magnetostriction increases with increasing proportion of Al content is believed that this magnetostriction is caused to increase hysteresis loss.
CITATION
Patent Literature
[0007]
Patent Document 1: Japanese Laid-Open Patent Publication No. 2007-247047
Patent Document 2: Japanese Laid-Open Patent Publication No. 2005-200756
Patent Document 3: Japanese Laid-Open Patent Publication No. 2003-253404
Patent Document 4: Japanese Patent Laid-Open 2013-44010 Publication No.
Patent Document 5: Japanese Laid-open Patent Publication No. 2014-210978
Summary of the Invention
Problems that the Invention is to Solve
[0008]
　The present invention has been made in view of the above problems, hitherto to further increase the proportion of Al content by the increase of hysteresis loss to the extent that the high-frequency iron loss had increased (range exceeding a certain limit) also aims at high-frequency iron loss is to be provided a low non-oriented electrical steel sheet with high productivity.
Means for Solving the Problems
[0009]
　The present inventors, in order to solve the above problems, the iron loss in the case of adding various chemical elements in steel containing a predetermined amount of Al, carried out an extensive research in particular changes in the hysteresis loss. As a result, heretofore also increases the proportion of Al content in the steel to the extent that the high-frequency iron loss had increased by an increase in hysteresis loss, be contained by a predetermined amount P in the steel, P is a steel sheet high-frequency iron loss by the effect on the texture is found that does not deteriorate (not increase). Further, if it has the steel texture is within a predetermined range the ratio I {100} / I {111} of the {100} plane intensity I {100} of relative {111} plane intensity I {111} of suppresses deformation twins occurs when the texture punching found that can further reduce high frequency iron loss.
[0010]
　Further, the cold rolling is facilitated by increasing the Al content reduced Si content. However, cold rolling becomes very difficult when the P content increases. Thus, P is is difficult to cold rolling, by appropriately controlled in accordance with an average grain size of the steel sheet immediately before cold rolling to solid solution strengthening parameter R, cold efficiently stably steel found that it is possible to between rolling. It was further found that the I {100} / I {111} by keeping the temperature of the steel sheet at a constant temperature in a predetermined temperature range of the heating process of the final annealing can be controlled to a predetermined range.
[0011]
　The present invention has been made based on these findings, the gist is as follows.
[0012]
　(1) non-oriented electrical steel sheet according to one embodiment of the present invention, in mass%, C: 0% ~ 0.0050 %, Si: 0.50% ~ 2.70%, Mn: 0.10% ~ 3.00%, Al: 1.00% ~ 2.70%, P: 0.050% ~ 0.100%, S: 0% ~ 0.0060%, N: 0% ~ 0.0050%, Ti : 0% to 0.008% V: 0% to 0.008% Nb: 0% to 0.008% Zr: contains 0% to 0.008% the balance being Fe and impurities chemical has a composition, wherein the chemical composition is represented by the following formula (1), satisfies the following formula (2) and the following formula (3), the crystal orientation distribution function of the surface near the pole figure measured by X-ray diffraction method and the plate thickness It is determined to give an average of the crystal orientation distribution function of the center, but the {100} plane intensity as I {100} of the {111} plane intensity I {111} Satisfies serial formula (4), the resistivity at room temperature of 60.0 × 10 -8 is a Omega · m or more, the thickness is 0.05 mm ~ 0.40 mm.
　　0.50 ≦ Al / (Si + Al + 0.5 × Mn) ≦ 0.83
　　(1) 1.28 ≦ Si + Al / 2 + Mn / 4 + 5 × P ≦ 3.90
　　(2) 4.0 ≦ Si + Al + 0.5 × Mn ≦ 7. 0
　　(3) 0.50 ≦ I {100} / I {111} ≦ 1.40 (4)
[0013]
　(2) The method of producing non-oriented electrical steel sheet according to one embodiment of the present invention, in mass%, C: 0% ~ 0.0050 %, Si: 0.50% ~ 2.70%, Mn: 0. 10% ~ 3.00%, Al: 1.00% ~ 2.70%, P: 0.050% ~ 0.100%, S: 0% ~ 0.0060%, N: 0% ~ 0.0050 %, Ti: 0% ~ 0.008 %, V: 0% ~ 0.008%, Nb: 0% ~ 0.008%, Zr: 0% ~ 0.008.%, the balance being Fe and impurities has a chemical composition consisting of, the chemical composition is represented by the following formula (5), the slab satisfying the following formula (6) and the following formula (7), hot rolled to produce a hot-rolled sheet is subjected to hot rolling step a; after said hot rolling step, a cold rolling step of producing a cold-rolled sheet having a thickness of 0.05 mm ~ 0.40 mm and subjected to cold rolling to the hot-rolled sheet After the cold rolling step, said and a recrystallization annealing step performing finish annealing the cold-rolled sheet, in the cold rolling step, an average crystal grain size D of the hot-rolled plate before the cold rolling ([mu] m) and the solid-solution strengthening parameter R represented by the following formula (8) satisfies the following equation (9), in the process of heating the cold-rolled sheet in the finish annealing step, 550 ° C. the temperature of the cold-rolled sheet keep 10 ~ 300 s at a constant temperature in the range of ~ 700 ° C..
　　0.50 ≦ Al / (Si + Al + 0.5 × Mn) ≦ 0.83
　　(5) 1.28 ≦ Si + Al / 2 + Mn / 4 + 5 × P ≦ 3.90
　　(6) 4.0 ≦ Si + Al + 0.5 × Mn ≦ 7. 0
　　(7) R = Si + Al / 2 + Mn / 4 + 5 × P (8)
[0014]
[Number 1]

[0015]
　(3) The method of producing non-oriented electrical steel sheet according to the above (2) is between the cold rolling step and the hot rolling step, hot-rolled sheet subjected to hot-rolled sheet annealing to the hot rolled plate it may further include an annealing step.
Effect of the invention
[0016]
　According to the present invention, by providing an inexpensive non-oriented electrical steel sheet further improved high-frequency iron loss, or the electrical equipment more compact, or it can further enhance the output and energy efficiency of electric equipment. In addition, it is possible to punch the non-oriented electrical steel sheet more easily omitting heated when punching the non-oriented electrical steel sheet, or can reduce the frequency of replacement of the mold due to wear. Therefore, it is possible to reduce the manufacturing cost of the electrical equipment. Further, according to the present invention, even cold rolling became difficult by increasing the resistivity of the non-oriented electrical steel sheet, non-oriented electrical was further improved high-frequency iron loss without lowering the productivity and the yield it can be produced inexpensively and stably to the steel plate. Therefore, the industrial value of the non-oriented electrical steel sheet according to the present invention is very high.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017]
[Figure 1] P content W 10/400 is a graph showing the effect on the relationship between the Al / (Si + Al + 0.5 × Mn).
[Figure 2] and {100} I / I {111} W 10/400 is a graph showing the relationship between.
DESCRIPTION OF THE INVENTION
[0018]
　Hereinafter, the non-oriented electrical steel sheet and a manufacturing method thereof according to an embodiment of the present invention will be described in detail.
[0019]
A. Non-oriented electrical steel sheet
　will be described below each structure in the non-oriented electrical steel sheet according to an embodiment.
[0020]
1. Chemical composition
　will be described first chemical composition of non-oriented electrical steel sheet according to the present embodiment. In the following, the content of each chemical element (%) is indicated in mass%.
[0021]
(1) Si: 0.50% ~
　2.70% Si is to increase the specific resistance of the steel sheet reduces the iron loss of the steel sheet. Therefore, it is necessary that the Si content is 0.50% or more. Further, Si content is preferable to be 1.00% or more, and more preferably is 1.20% or more. On the other hand, there is a possibility that the steel sheet is broken during the cold rolling and the Si content is excessive. Further, in the present embodiment, as described later, thereby increasing the Al content is reduced as much as possible Si content. Furthermore, Si is to prevent the activities of slip system of the steel sheet, to promote the deformation twins development when deformation occurs. This deformation twins, since prevent movement of the domain wall, when after punching deformation twins is large, the hysteresis loss is increased. From these viewpoints, Si content is required to be less 2.70%. Further, Si content is preferable to be less 2.50%, and more preferably is not more than 2.00%. Accordingly, Si content of the non-oriented electrical steel sheet of the present embodiment is 0.50% to 2.70%.
[0022]
(2) Mn: 0.10% ~
　3.00% Mn is to become MnS by combining with S, to prevent the steel embrittlement by S. Therefore, Mn content is required to be 0.10% or more. Moreover, Mn, Si, increases similarly resistivity and Al to reduce the iron loss of the steel sheet. The Mn content and the Si content and compares the two steel different same resistivity, the hardness of the Mn content is high steel is lower than the hardness of the Si content is high steel. Therefore, Mn content is high steel break during cold rolling, compared with the Si content higher steel is unlikely to occur. Therefore, Mn content is preferable to be 0.50% or more, and more preferably 1.00% or more. However, the alloy cost increases the Mn content is excessive. From this point of view, Mn content is required to be less 3.00%. Further, Mn content is preferable to be less 2.50%, and more preferably is not more than 2.00%. Therefore, Mn content of the non-oriented electrical steel sheet of the present embodiment is 0.10% ~ 3.00%
[0023]
(3) Al: 1.00% ~
　2.70% Al is increased similarly resistivity and Si and Mn to reduce the iron loss of the steel sheet. The effect on Al increase specific resistance per unit mass is substantially equal to Si, the effect of Al is on the hardness increase per unit mass is about 1/3 ~ 1/2 of the Si . Therefore, it is possible to achieve both high productivity and high resistivity by increasing the content of Al, Al is an important element in the present embodiment. Therefore, Al content is required to be 1.00% or more. Further, Al content is preferable to be 1.50% or more, and more preferably is 1.60% or more. On the other hand, when the Al content is excessive, the saturation magnetic flux density decreases, also decreases the magnetic flux density at the same excitation conditions. In this respect, Al content is required to be less 2.70%. Further, Al content is preferable to be less 2.50%, and more preferably is 2.40% or less. Therefore, Al content of the non-oriented electrical steel sheet of the present embodiment is 1.00% to 2.70%.
[0024]
(4) P: 0.050% ~ 0.100%
　P improves the texture of the non-oriented electrical steel sheet, to facilitate magnetization. In addition, P is, to improve the workability at the time of punching. Therefore, P content is required to be 0.050% or more. Also, P content is preferable to be 0.055% or more, and more preferably 0.060% or more. However, a large amount of the Si content and the Mn content and the Al content in the high resistivity non-oriented electrical steel sheet, it can occur when the P content exceeds 0.100% breakage during cold rolling there is sex. From this point of view, P content is required to be 0.100% or less. Also, P content is preferable to be less 0.090%, and more preferably a 0.080% or less. Accordingly, P content of the non-oriented electrical steel sheet of the present embodiment is 0.050% to 0.100%.
[0025]
(5) balance
　balance being Fe and impurities.
[0026]
　C is an impurity, C content may be 0%. C content precipitated iron loss increases significantly fine carbides in steel exceeds 0.0050%. Therefore, it is necessary to make the C content 0% to 0.0050%.
[0027]
　S is an impurity, S content may be 0%. S content sulfides such as MnS exceeds 0.0060% increases significantly in many precipitates in the steel core loss. Further, S is finish to inhibit also the grain growth during annealing, there is a case where iron loss is increased can not ensure fair average crystal grain size and a high S content of the steel. Therefore, it is necessary to make the S content to 0% 0.0060%.
[0028]
　N is an impurity, N content may be 0%. N content iron loss is significantly increased by increasing the nitride exceeds 0.0050%. Further, N is finishing to inhibit also the grain growth during annealing, there is a case where iron loss is increased can not ensure fair average crystal grain size and high N content of the steel. Therefore, the N content is required to be 0% to 0.0050%.
[0029]
　Ti, V, Nb, Zr is an impurity, it may be 0%. These Ti, V, Nb, Zr, since an adverse effect on the grain growth during finish annealing, it is desirable to reduce as much as possible. Therefore, Ti content, V content, Nb content, Zr content is required to be 0% to 0.008%, respectively.
[0030]
(6) three chemical elements (Si, Al, Mn) ratio of effect on Al resistivity accounted for the effect on the specific resistance X: 0.50 ~ 0.83
　In the present embodiment, the steel sheet resistivity change amount is Al occupy substantially proportional to the value of (Si + Al + 0.5 × Mn ), Al / (Si + Al + 0.5 × Mn) has three chemical elements (Si, Al, Mn) is effective on the resistivity It shows the proportion of effect on resistivity. When the value of the left Al / maintaining the value (Si + Al + 0.5 × Mn ) of (Si + Al + 0.5 × Mn ) is increased, the specific resistance steel sheet during cold rolling or reduce the load of cold rolling remains equivalent to the steel plate and to prevent the break. Therefore, in the present embodiment, Al / (Si + Al + 0.5 × Mn) is 0.50 or more, i.e., a range indicated by the equation (10). In this range, the increase in hysteresis loss due to the increase in the proportion of Al content relative to the total amount of Si content and Al content, the iron loss had increased in the conventional method. On the other hand, in the present embodiment can also be maintained or decreased iron loss in a range indicated by the equation (10) by controlling the texture and the range of the P content. Further, in the present embodiment, Si content, since Al content and the Mn content is required to be within the aforementioned range, Al / (Si + Al + 0.5 × Mn) is 0.83 or less, i.e., a range indicated by the following equation (11). Therefore, in the present embodiment, Al / (Si + Al + 0.5 × Mn) satisfies the following equation (12). Also, Al / (Si + Al + 0.5 × Mn) may be 0.51 or more, may be 0.80 or less. In the following, as shown by the following formula (13), also it is expressed Al / a (Si + Al + 0.5 × Mn ) and X.
[0031]
　　Al / (Al + 0.5 × Si + Mn) ≧ 0.50
　　(10) Al / (Al + 0.5 × Si + Mn) ≦ 0.83
　　(11) 0.50 ≦ Al / (Al + 0.5 × Si + Mn) ≦ 0.83 (
　　12) X = Al / (Al + 0.5 × Si + Mn) (13)
　ここで,式中の各元素記号は鋼中の各元素の含有量(質量%)を示す.
[0032]
(7) solid-solution strengthening parameter R:
　1.28 ~ 3.90 Si, Al, Mn, and P is a solid solution strengthening ability is high, the steel sheet is steel sheet cold during rolling is excessively containing these chemical elements there is a risk of rupture. Therefore, as shown in the following formula (14), Si, Al, as an index representing the solid solution strengthening ability of Mn, and P, defines the solid solution strengthening parameter R, in the present embodiment, the solid solution strengthening parameter R It is referred to as 3.90 or less. Further, in the present embodiment, Si content, Al content, Mn content, and because the P content is required to be within the range described above, the solid-solution strengthening parameter R is a 1.28 or higher . Therefore, solid solution strengthening parameter R, as shown in the following formula (15), is 1.28 to 3.90. Further, solid-solution strengthening parameter R may be 1.50 or more or 2.00 or more, may be 3.80 or less.
[0033]
　　R = Si + Al / 2 + Mn / 4 + 5 × P
　　(14) 1.28 ≦ R ≦ 3.90 (15)
　wherein each element symbol in the formula have the content of each element in the steel (mass%).
[0034]
2. Specific resistance ρ at room temperature: 60.0 × 10 -8 Omega · m or more
　resistivity at room temperature is determined primarily Si content, Al content and the Mn content. From the viewpoint of securing low core loss in a high frequency, the resistivity at room temperature is 60.0 × 10 -8 It is necessary that the Omega · m or more. The specific resistance at room temperature, 65.0 × 10 -8 When Omega · m or more preferred. Specific resistance at room temperature, 85.0 × 10 -8 Omega · m or less or 70.0 × 10 -8 may be less than or equal Omega · m.
[0035]
　To obtain a specific resistance in the room temperature, as shown in the following formula (16), it is necessary that is 4.0 ~ 7.0 (Si + Al + 0.5 × Mn). The (Si + Al + 0.5 × Mn ) is more preferably is 4.4 to 7.0. Hereinafter, as represented by the following formula (17) may also be expressed this (Si + Al + 0.5 × Mn ) and E.
　The specific resistance at room temperature is measured by a known four-terminal method. Taken at least one sample from a position apart more than 10cm from the edge of the steel sheet, measuring the specific resistivity after removing the insulating coating from the sample. The removal of the insulating coating may be used an alkaline aqueous solution such as for example, 20% aqueous sodium hydroxide.
　　4.0 ≦ Si + Al + 0.5 × Mn ≦ 7.0
　　(16) E = Si + Al + 0.5 × Mn (17)
　wherein each element symbol in the formula have the content of each element in the steel (mass%) .
[0036]
3. The average crystal grain size
　average grain size of the non-oriented electrical steel sheet (average diameter of the crystal grains) is preferably in the range of 30 [mu] m ~ 200 [mu] m. If the average crystal grain size is 30μm or more, the magnetic properties of the individual recrystallized grains is high, the magnetic flux density and iron loss improved. When the average crystal grain size is 200μm or less, eddy current loss is reduced, further iron loss is reduced.
[0037]
　The average crystal grain size of the non-oriented electrical steel sheet ([mu] m) is determined by applying a cutting method with respect to photographs taken through an optical microscope at a magnification of 50 times. Samples are three taken from a position apart more than 10cm from the steel edge. Longitudinal section of the samples; For photos (plane including the plate thickness direction and the rolling direction a plane perpendicular to the sheet width direction) to apply a cutting method. In the cutting method, the average mean value of the grain size of the average value and the rolling direction of the grain size in the thickness direction to determine the average grain size. The number of grains to be measured, it is desirable that the collected sample one per at least 200 or more.
[0038]
4. The ratio of the {100} plane intensity I {100} of the relative intensity I {111} of the {111} plane (I {100} / I { 111}): 0.50 ~ 1.40
　nonoriented according to this embodiment electrical steel sheets, as shown in the following formula (18), the ratio of {100} plane intensity I {100} of relative {111} plane intensity I {111} of (I {100} / I {111}) 0 It has a texture which is .50 to 1.40. As shown in FIG. 2, the I {100} / I {111 } is less than 0.50, not desirable magnetic characteristics are obtained, the iron loss is increased. On the other hand, when the I {100} / I {111 } is greater than 1.40, deformation twins occur grains increases significantly during punching. This deformation twins, to impede the movement of the domain walls, the iron loss is degraded as shown in FIG. Samples are three taken from a position apart more than 10cm from the steel edge. These apply X-ray diffractometry (reflection method) to a transverse plane of the sample (thickness direction perpendicular cross-section). Incidentally, thickness position measuring (position in the thickness direction of the cross section) is the sheet thickness from the surface vicinity (point away from the surface by a distance of thickness of 1/10 of steel) and the thickness center (the surface of the steel sheet 1/2 of the distance is only a remote location). For both of these near surface and thickness center, three pole figure by a reflection method using X-ray diffraction apparatus (X-ray diffraction method) ({200} plane, {110} plane, the pole of the {211} plane Figure) is measured. Obtaining a crystal orientation distribution function with respect to the plate thickness position (ODF) by calculation from these pole figure. Thereafter, the ODF of ODF and the plate thickness center of the near-surface averaged to determine the I {100} and I {111}.
　　0.50 ≦ I {100} / I {111} ≦ 1.40 (18)
[0039]
5. Thickness: 0.05 ~ 0.40 mm
　in the present embodiment, it is assumed that to achieve low iron loss at essentially high frequency. It is possible to obtain a low iron loss and the plate thickness is small at high frequencies, the thickness is required to be less 0.40 mm. Further, the thickness is preferably 0.30mm or less, and more preferably not more than 0.20 mm. On the other hand, flatness is lowered extremely space factor of the steel sheet is deteriorated in the steel sheet when thinning the thickness excessively, the core of productivity sometimes lowered. Therefore, the thickness is required to be 0.05mm or more. Further, the thickness is preferably at least 0.10 mm, more preferably 0.15mm or more.
[0040]
6. Production process
　the non-oriented electrical steel sheet according to the present embodiment, it is preferable to be manufactured by the manufacturing method of the non-oriented electrical steel sheet according view of reducing the production cost in the following embodiments.
[0041]
B. Method for producing a non-oriented electrical steel sheet
　will be described each step in the method for manufacturing a non-oriented electrical steel sheet according to an embodiment.
[0042]
1. Hot rolling step
　in the hot rolling process, the slabs having the chemical composition described above, a hot-rolled sheet is subjected to hot rolling.
[0043]
　Conditions of the hot rolling is not particularly limited. Thickness of hot rolled sheet (finishing thickness) is preferably in the 1.0 mm ~ 2.5 mm. When the plate thickness is less than 1.0mm, less load on the hot rolling machine, a high productivity in the hot rolling process.
[0044]
2. Cold rolling step
　in the cold rolling step, after the hot rolling step, the cold-rolled sheet subjected to cold rolling to hot-rolled sheet.
[0045]
　In cold rolling, it is necessary above formula and the average crystal grain size D of the solid-solution hardening parameter R and the hot-rolled sheet shown in (14) ([mu] m) satisfies the following equation (19). If the average crystal grain size D of the solid-solution strengthening parameters R and hot-rolled sheet ([mu] m) satisfies the following equation (19), can be obtained cold-rolled sheet without causing breakage during cold rolling. On the other hand, the average crystal grain size D of the solid-solution strengthening parameters R and hot-rolled sheet ([mu] m) may not satisfy the following equation (19), which occurs breakage at the time of cold rolling, to obtain the product (non-oriented electrical steel sheet) can not.
[0046]
[Number 2]

[0047]
　The average crystal grain diameter D ([mu] m) is determined by applying a cutting method with respect to photographs taken through an optical microscope at a magnification of 50 times. Samples are three taken from a position apart more than 10cm from the edge of the hot-rolled sheet. Longitudinal section of the samples; For photos (plane including the plate thickness direction and the rolling direction a plane perpendicular to the sheet width direction) to apply a cutting method. In the cutting method, the average mean value of the grain size of the average value and the rolling direction of the grain size in the thickness direction to determine the average grain size. The number of grains to be measured, it is desirable that the collected sample one per at least 200 or more.
[0048]
　Here, the average crystal grain diameter D ([mu] m) is an average particle size of the hot-rolled sheet immediately before cold rolling (directly cold rolled as hot-rolled sheet). That is, "cold rolling immediately before the steel sheet" as immediately after the hot rolling step cold rolling process is followed, meaning hot-rolled sheet obtained by hot-rolling process. As will be described later, when performing hot-rolled sheet annealing step between the hot rolling step and cold rolling step, "cold rolling immediately before the steel sheet" is hot-rolled sheet obtained by hot-rolled sheet annealing step It means annealed sheets (hot-rolled sheet having undergone the hot-rolled sheet annealing).
[0049]
　Rolling reduction in cold rolling is preferably 60% to 95%. When rolling reduction is 60% or more, it is possible to obtain the effect of P has on the texture of the non-oriented electrical steel sheet more stably. Further, when the rolling reduction is less than 95%, the non-oriented electrical steel sheet industrially it can be stably manufactured. In cold rolling, for the reasons described in the above "A. non-oriented electrical steel sheet", the thickness of the cold-rolled sheet and 0.05 mm ~ 0.40 mm.
[0050]
　Temperature of the steel sheet during cold rolling may be at room temperature. Further, cold rolling, the steel sheet temperature may be as warm rolling at 100 ℃ ~ 200 ℃. The steel sheet temperature to heat up to 100 ° C. ~ 200 ° C., to the steel sheet may be preheated, it may be preheated rolls.
[0051]
　Further, the number of passes in the cold rolling is preferably a 3 passes or more. In this cold rolling, the rolling reduction of the first pass is preferably 10% to 25%. Further, preferably the total rolling reduction from the first pass to the second pass (cumulative reduction ratio) is 35% to 55%. Further, the total rolling reduction from the first pass to the last pass (cumulative reduction ratio) is preferably from 60 to 95% as described above. When the first pass of the rolling reduction is 10% or more, high production efficiency of the cold-rolled sheet. Further, when the first pass reduction ratio is less than 25%, the steel sheet can pass between the fast and stable roll. If the total rolling reduction from the first pass to the second pass is 35% or more, the steel sheet can pass between the fast and stable roll. Further, when the first pass from the total reduction rate of up to the second pass is less than 55%, load on the cold rolling mill is small.
[0052]
　3. Recrystallization annealing step
　in the recrystallization annealing step, after the cold rolling step is subjected to a finish annealing the cold-rolled sheet and non-oriented electrical steel sheet.
[0053]
　Finish annealing step includes a heating step of heating the cold-rolled sheet, cooling process of cooling a holding step of holding the temperature of the heated cold-rolled sheet at a constant temperature in a predetermined temperature range, the cold-rolled sheet after the holding step with the door. As I {100} / I {111} of a non-oriented electrical steel sheet is in the range from 0.50 to 1.40 in the heating process, a certain range of the temperature of the cold-rolled sheet 550 ° C. ~ 700 ° C. it is necessary intermediate holding to hold between 10 ~ 300 s at temperature. In the range of this 550 ℃ ~ 700 ℃, (a plane parallel to the surface of the steel sheet, i.e., the plane including the rolling direction and the plate width direction) plate surface to the amount and the plate surface of the crystal grains having a {100} plane to { 111} can control the amount of crystal grains having a face. The time temperature of cold-rolled plate is maintained at a constant temperature in this range is less than 10s, I {100} / I {111} to obtain a texture in the range of 0.50 to 1.40 it can not, crystal grains deformation twins occurs during punching is increased considerably. Meanwhile, the time the temperature of the cold-rolled plate is maintained at a constant temperature in the range is more than 300 s, productivity is low in the non-oriented electrical steel sheet. To enhance the productivity, and more preferably the holding time is 30s or less. Further, in the temperature range exceeding the temperature range and 700 ° C. of less than 550 ° C., even if no matter how controlling the time for maintaining the temperature of the cold-rolled sheet at a constant temperature, is not sufficiently changed I {100} / I {111} Therefore, it is not possible to obtain an appropriate texture. After the intermediate holding, the heating process, the temperature of the cold-rolled sheet is further heat the cold-rolled sheet to a target temperature in excess of 700 ° C.. Thereafter, the holding step to hold the temperature of the cold-rolled plate to a predetermined temperature range including the target temperature. This temperature range is, if it is 1100 ° C. or less, since load on the annealing equipment is small, preferably a 1100 ° C. or less. Moreover, as the average crystal grain size of the non-oriented electrical steel sheet is in the range of 30 [mu] m ~ 200 [mu] m, the temperature of the cold-rolled sheet is held more 1s in the range of more than 950 ° C. preferred. On the other hand, the time that the temperature of the cold-rolled sheet is maintained in the range of more than 950 ° C. is not more than 300 s, productivity is sufficient. From the above, in the holding step, more preferable to hold 1 ~ 300 s within the temperature of the cold-rolled sheet of 950 ~ 1100 ° C.. The final annealing, for the reasons described in the above "A. non-oriented electrical steel sheet", preferably the average grain size of 30 [mu] m ~ 200 [mu] m after final annealing is obtained.
[0054]
4. Hot-rolled sheet annealing step
　in the present embodiment, it may be performed hot rolled sheet annealing step between the hot rolling step and cold rolling step. The hot-rolled sheet annealing step, Al content can further enhance the effect of P has on the texture of the steel sheet is 1.0% or more, it can be secured and a high magnetic flux density and low iron loss more stably. Further, in the hot-rolled sheet annealing step, to release the strain of processing tissue into which they are introduced during hot rolling, reducing the hardness of the hot-rolled sheet. Therefore, the hot rolled sheet annealing, damage to the steel sheet at the time of reduction or cold rolling loads on the cold rolling mill (e.g., the occurrence of ridging) can or reduced. Therefore, it is preferable to perform the hot-rolled sheet annealing step of performing hot-rolled sheet annealing to the hot rolled sheet obtained by the hot rolling process.
[0055]
　The hot-rolled sheet annealing step comprises a heating step of heating the hot-rolled sheet, a holding step of holding the temperature of the heated hot-rolled sheet in a predetermined range, and a cooling process of cooling the hot-rolled sheet after holding step .
[0056]
　The hot-rolled sheet may contain different processed structure according to rolling conditions. Moreover, the hot rolled sheet, since the containing Al 1.0% or more, the temperature recrystallization is completed is in the range of 900 ℃ ~ 950 ℃. Therefore, in order to prevent damage of the steel sheet during cold rolling to obtain a recrystallized structure stably from processed structure it is preferable to anneal the hot rolled sheet at a temperature range of more than 950 ° C.. Further, for the same reason, it is preferable that the annealing time at this temperature range as 30s or more. When the hot rolled sheet is annealed at 1100 ° C. or less, since load on the annealing equipment is small, the annealing temperature is 1100 ° C. or less preferred. Annealing time is not more than 3600s, it is possible to maintain a high productivity, it is preferably not more than 3600s. Further, when the solid solution strengthening parameter R is 3.80 or less, the annealing temperature is 1000 ° C. or higher, it is possible to increase the advantageous effect achieved by the above formula (19). Therefore, the annealing temperature is preferably 1000 ° C. or higher.
[0057]
　Further, in the cooling process, in order to further improve the texture by reducing the grain boundary segregation of P, making the average cooling rate in the temperature range from 950 ° C. to 600 ° C. and 1 ℃ / s ~ 30 ℃ / s It is preferred.
[0058]
　From the above, in the hot-rolled sheet annealing, after holding between 30s ~ 3600s in the range of 950 ° C. ~ 1100 ° C. The temperature of the hot-rolled sheet, the average cooling rate in the temperature range from 950 ° C. to 600 ° C. is 1 ° C. / s ~ more preferable to cool such that the 30 ° C. / s.
[0059]
　The present invention is not limited to the above embodiment. The above embodiments are only specific examples, the technical scope of the present invention include those having the feature points substantially identical feature point described in claims of the present invention.
Example
[0060]
　It will be specifically described an embodiment according to the reference experiment, and the present invention. Incidentally, the column underlined granted in the following table, we show that the condition is not satisfied the required conditions of the present invention.
[0061]
(Reference Experiment 1) Effect of the P content
　of steel having the chemical composition shown in Table 1 No. 1 to 10 is dissolved in vacuo, casting to obtain a slab. The slab was obtained hot-rolled sheet having a thickness of hot rolled 2.0 mm. Then, the hot-rolled sheet annealing, after heating the hot rolled sheet up to 1000 ° C., the temperature of the hot-rolled sheet and 60s held at 1000 ° C., the value of the average cooling rate from 950 ° C. to 600 ° C. is shown in the following Table 2 cooling the hot rolled sheet from 1000 ° C. to room temperature so as to. After hot-rolled sheet annealing, the hot-rolled sheet was cold-rolled to obtain a cold-rolled sheet having a thickness of 0.35 mm. The finish annealing to 1s keeping the temperature of the cold-rolled sheet at 1050 ° C. performed with respect to cold-rolled sheet to obtain a non-oriented electrical steel sheet (sample No.1 ~ 10).
[0062]
　From this non-oriented electrical steel sheets punched veneer specimens 55mm square was measured resistivity ρ [Ω · m] at room temperature of the veneer specimens. Further, the magnetic flux density of 1.0 T, the magnetic flux frequency is 400Hz, in addition to the veneer specimens were magnetized veneer specimens, the high-frequency iron loss W veneer specimens 10/400 [W / kg] It was measured. In addition, a photograph of an edge surface of the veneer specimens (blanked surface) was photographed through an optical microscope at a magnification of 50 times, variations and about 300 crystal grains in this picture, in the about 300 grains bi counted and the number of crystal grains crystallized occurs, was determined proportion of crystal particles deformation twins occurs to the total number of crystal grains (about 300) (twin incidence). Each sample No. Of Ro, W 10/400 show, the twins incidence in Table 2. It should be noted that all of the sample No. In the average grain size of the non-oriented electrical steel sheet was about 100 [mu] m.
[0063]
[Table 1]

[0064]
[Table 2]

[0065]
　Sample No. In the group of 1 ~ 4, P content was about 0.01%. Sample No. In this sample group 2 Sample No. Compared 1, W by an increase in [rho 10/400 is lowered. In addition, sample No. 3 sample No. Compared to 2, [rho despite the same, W due to an increase in X 10/400 increased. Sample No. In the group of 5 ~ 10, P content was about 0.08%. Sample No. In this sample group 7 the sample No. Sample have the same ρ and 7 No. Compared to 6, W in spite X increases 10/400 could be maintained. In addition, sample No. In 5, for solid solution strengthening parameter R is too high, breaking of the hot-rolled plate in cold rolling occurs, the non-oriented electrical steel sheets were not obtained. FIG 1, W in each sample group 10/400 shows the relationship between the Al / (Si + Al + 0.5 × Mn), FIG. 1, P content W 10/400 between the X clearly it represents the effect on the relationship. However, in FIG. 1, Sample No. 5 is excluded. As can be seen from Table 1 and FIG. 1, if the P content is about 0.01%, X is W with increasing X to reach 0.38 10/400 was reduced, the X 0.38 W with the increase of X after more than 10/400 value of has increased. On the other hand, if the P content of about 0.08%, X is lower W be increased 10/400 could be maintained. Thus, when including the steel of 0.05% P Low, W with increasing X 10/400 because there is little increase in, W 10/400 to enhance the work of the steel while maintaining the can.
[0066]
　In addition, sample No. As can be seen from 1-4, to maintain ρ of the non-oriented electrical steel sheet in a high level, the more the Si content is large twin incidence is increased. The ρ Increasing the X reduce the Si content while maintaining a high level and can reduce the twinning incidence. In this case, the movement of the domain wall is facilitated, W 10/400 are expected to be reduced. However, the sample No. In 1 ~ 4, W also to reduce the twin incidence 10/400 could not be reduced. In addition, sample No. 6-8 sample No. Compared to 2-4, twinning incidence was not nearly independent of P content. Therefore, P content is W 10/400 effect on the relationship between the X is not a reduction in the twinning incidence, it can be seen that provided by the improvement of texture due to the increase in the P content .
[0067]
(Reference Experiment 2) Effect of the average grain size D [[mu] m]
　shown in Table 1 Steel No. 1,3,4,5,7, and 8 were dissolved in vacuo to cast to obtain a slab. The slab was obtained hot-rolled sheet having a thickness of hot rolled 2.0 mm. Then, the hot-rolled sheet annealing, after heating to the annealing temperature indicated the hot rolled sheet in the following Table 3, the temperature of the hot-rolled sheet and 60s held at that temperature, the average cooling rate from 950 ° C. to 600 ° C. below the hot-rolled sheet so that the values shown in Table 3 was cooled from the holding temperature to room temperature.
[0068]
　The average crystal grain size of the hot-rolled sheet annealed sheets the surface hardness Hv (Vickers hardness) at (average crystal grain size of the cold-rolled immediately before the steel plate) D [[mu] m] and 1 kgf [-] and was measured. The average crystal grain size D [[mu] m] and a surface hardness Hv [-] is shown in Table 3.
[0069]
　Then, to obtain a hot rolled sheet annealed sheets and cold-rolled cold-rolled sheet of thickness 0.20mm (sample No.1-a ~ 8-d). Number of passes in the cold rolling was 5 paths. The rolling reduction of the first pass 15%, the total reduction ratio from the first pass to the second pass is 40% and the reduction ratio of the total and 90.0%. Table 3 shows the presence or absence of breakage in cold rolling.
[0070]
[table 3]

[0071]
　Sample No. In 5-a ~ 5-d, in addition to the solid solution strengthening parameter R is too high, since this solid solution parameter R and the average crystal grain size D [[mu] m] and did not satisfy the above (19), cold hot-rolled sheet annealing plate was broken during rolling. Sample No. In 7-a, since the solid solubility parameter R mean crystal grain size D [[mu] m] and did not satisfy the above (19), hot-rolled sheet annealing plate was broken during cold rolling. Sample No. 5-a ~ 5-d and the sample No. Sample except 7-a was able to roll the hot-rolled sheet annealed sheets without breaking in cold rolling.
[0072]
(Example 1)
　Steel shown in Table 1 No. 6, 7 and 8 were dissolved in vacuo to cast to obtain a slab. The slab was obtained hot-rolled sheet having a thickness of hot rolled 2.0 mm. Then, the hot rolled sheet annealing, the post-heating hot-rolled sheet up to 1000 ° C., the temperature of the hot-rolled sheet was held between 60s to 1000 ℃, 1 ℃ / s ~ is the average cooling rate from 950 ° C. to 600 ° C. the hot-rolled sheet to be 30 ° C. / s and then cooled to room 1000 ° C.. Thereafter, the hot rolled sheet annealed sheets and cold-rolled to obtain a cold-rolled sheet of thickness 0.35 mm. Subsequently, the final annealing, the cold-rolled sheet was heated to 1050 ° C., after 1s maintaining the temperature of the cold-rolled sheet at 1050 ° C., the cold-rolled sheet was cooled to room 1050 ° C., the non-oriented electrical steel sheet (sample No.6-e ~ 8-f) was obtained. Sample No. In 6-f, 7-f, 8-f, as shown in Table 4, in the heating process of heating the temperature of the cold-rolled sheet to 1050 ° C., and held between the 20s the temperature of the cold-rolled sheet at 600 ° C..
[0073]
　Similar to (Reference Experiment 1), the high frequency core loss of the non-oriented electrical steel sheet obtained W 10/400 [W / kg] and was measured twins incidence. Further, to measure the pole figure near the surface and thickness center of a non-oriented electrical steel sheet by using an X-ray diffraction apparatus. The ODF of ODF and the plate thickness center in the vicinity of the surface of these in the pole figure was calculated and determined I {100} / I {111 } by averaging these ODF. W 10/400 , twin incidence, and the result of I {100} / I {111 } are shown in Table 4. In addition, all of the sample No. In the average grain size of the non-oriented electrical steel sheet was about 100 [mu] m.
[0074]
[Table 4]

[0075]
　For example, sample No. The 7-f sample No. 7-e As can be seen when compared to, X is the steel is 0.50 or more (Steel No.7 and 8), an intermediate holding which holds between 20s the temperature of the cold-rolled plate heating process of final annealing at 600 ° C. When you add a, iron loss is greatly reduced. Further, reduces the I {100} / I {111} by the intermediate holding, twins rate decreased. Is not clear detailed reason twinning incidence decreases, since the deformation twinning occurs along the <111> direction of the {211} plane, the I {100} / I {111} is the occurrence of deformation twins It is considered influential with. As a result, the texture I {100} / I {111} is 0.50 to 1.40 is considered that the occurrence of deformation twins when punching is inhibited.
[0076]
　On the other hand, sample No. 6-f and the sample No. 6-e and as can be seen when comparing the, in steel (Steel No.6) X is less than 0.50, the intermediate holding to hold between 20s to the heating process of the final annealing temperature of cold-rolled plate at 600 ° C. It is added, I {100} / I {111}, twin incidence, iron loss, hardly changed.
[0077]
　Thus, in the heating process of the final annealing, if X is held at a constant temperature between 10 ~ 300 s within the range of the temperature of the cold-rolled sheet 550 ° C. ~ 700 ° C. is 0.50 or more, I {100} / I {111} can be obtained texture is from 0.50 to 1.40. On the other hand, if X does not hold the temperature at or cold-rolled sheet is less than 0.50 at a constant temperature between 10 ~ 300 s in the range of 550 ° C. ~ 700 ° C. is, I {100} / I {111} but it is impossible to obtain a texture which is 0.50 to 1.40.
[0078]
(Example 2)
　Steel having the chemical composition shown in Table 5 and 6 No. 11 to 65 dissolved in a vacuum, casting to obtain a slab. The slab was obtained hot-rolled sheet having a thickness of hot rolled 2.0 mm. Then, the hot-rolled sheet annealing, after heating the hot rolled sheet up to 1000 ° C., the temperature of the hot-rolled sheet and 60s held at 1000 ° C. or 1050 ° C., the average cooling rate following Table from 950 ° C. to 600 ° C. 7 cooling the hot rolled sheet from 1000 ° C. to room temperature and so the values shown in 8. The average crystal grain size of the hot rolled sheet annealed sheets (average crystal grain size of the cold-rolled immediately before the steel plate) D [μm] were measured. The average crystal grain size D of the [[mu] m] shown in Tables 7 and 8.
[0079]
　Then, the hot rolled sheet annealed sheets and cold-rolled to obtain a cold-rolled sheet of thickness 0.35 mm. Number of passes in the cold rolling was six passes. The rolling reduction of the first pass 20%, the total reduction ratio from the first pass to the second pass is 50% and the reduction ratio of the total and 82.5%. Further, in the heating process of the final annealing, the cold-rolled sheet was heated to 600 ° C., the temperature of the cold-rolled sheet and 20s held at 600 ° C., was further heated cold-rolled sheet to 1050 ° C.. Then, in continuation of the course of the final annealing, the heated cold-rolled sheet was 1s maintained at 1050 ° C., to obtain a non-oriented electrical steel sheet (sample No.11 ~ 65).
[0080]
　From this non-oriented electrical steel sheets punched veneer specimens 55mm square was measured resistivity ρ [Ω · m] at room temperature of the veneer specimens. Further, the magnetic flux density B at the magnetizing force of 5000A / m of the single plate specimen 50 [T], and W 10/400 was measured [W / kg]. [rho [Omega · m], B 50 [T], and W 10/400 shows the results of [W / kg] Table 9 and 10. In addition, any of the sample No. But, the average crystal grain size of the non-oriented electrical steel sheet was about 100 [mu] m.
[0081]
[table 5]

[0082]
[Table 6]

[0083]
[Table 7]

[0084]
[Table 8]

[0085]
[Table 9]

[0086]
[Table 10]

[0087]
　Sample No. In 11 ~ 14, Si content, since ρ and E is too small, W 10/400 was higher. Sample No. In 15-18, in addition to Si content is too large, the R does not satisfy the above equation (15), the steel sheet was broken during cold rolling. In addition, sample No. In 19-22, in addition to the Mn content is too high, the X and I {100} / I {111 } did not satisfy the above (12) and (18) respectively, W 10/400 was high . Sample No. In 23-26, since the chemical composition and texture were inadequate, W 10/400 was high. These sample No. In, Mn content is too high, in addition to the Al content is too low, [rho is low, E is small. Furthermore, X and I {100} / I {111 } did not satisfy the above (12) and (18) respectively. Sample No. In 27-30, in addition to the Al content is too high, the I {100} / I {111 } did not satisfy the above equation (18), W 10/400 was high. Sample No. In 31, since the P content was too low, W 10/400 was high.
[0088]
　On the other hand, sample No. In 32 to 65, since the chemical composition and manufacturing conditions of the steel was appropriate, was excellent in manufacturability in cold rolling (productivity and yield). In addition, these sample No. In order specific resistance and texture of the steel sheet was appropriate, W 10/400 was low.
[0089]
　2 shows, sample No. 19 to 22 and 27 were created from data and 30 and 32 - 65, W and {100} I / I {111} 10/400 shows a graph representing the relationship between the. FIG 2 from I {100} / I {111 } is the W in the range of 0.5 to 1.4 10/400 can be reduced to a minimum of.
Industrial Applicability
[0090]
　According to the present invention, it is possible to provide an inexpensive non-oriented electrical steel sheet and a manufacturing method thereof further improved high-frequency iron loss, the industrial applicability of the present invention is great.

claims
[Claim 1]
　By
mass%,
C:
0% ~ 0.0050%, Si: 0.50% ~ 2.70%,
Mn: 0.10% ~ 3.00%, Al: 1.00% ~ 2.70%, P:
0.050 Pasento ～ 0.100 Pasento, S: 0 Pasento ～0.0060 Pasento, N: 0 Pasento ～ 0.0050 Pasento, Ti: 0 Pasento ～ 0.008 Pasento, V: 0 Pasento ～ 0.008 %, Nb: 0% ~ 0.008%, Zr: 0% ~ 0.008%, containing, having a chemical composition the balance being Fe and impurities, 　wherein the chemical composition is represented by the following formula (1), the following satisfies equation (2) and the following formula (3), 　is determined to give an average of the crystal orientation distribution function of the crystal orientation distribution function and the plate thickness center of the surface near the pole figure measured by X-ray diffractometry, {100} plane intensity as I {100} of the {111} plane intensity I {111} satisfies the following formula (4), 　the ratio at room temperature Anticancer 60.0 × 10 -8 is a Omega · m or more, 　the thickness is 0.05 mm ~ 0.40 mm non-oriented electrical steel sheet, characterized in that. 　　0.50 ≦ Al / (Si + Al + 0.5 × Mn) ≦ 0.83 　　(1) 1.28 ≦ Si + Al / 2 + Mn / 4 + 5 × P ≦ 3.90 　　(2) 4.0 ≦ Si + Al + 0.5 × Mn ≦ 7. 0 　　(3) 0.50 ≦ I {100} / I {111} ≦ 1.40 (4)

[Claim 2]
　By
mass%,
C:
0% ~ 0.0050%, Si: 0.50% ~ 2.70%,
Mn: 0.10% ~ 3.00%, Al: 1.00% ~ 2.70%, P:
0.050 Pasento ～ 0.100 Pasento, S: 0 Pasento ～0.0060 Pasento, N: 0 Pasento ～ 0.0050 Pasento, Ti: 0 Pasento ～ 0.008 Pasento, V: 0 Pasento ～ 0.008 %, Nb: 0% ~ 0.008%, Zr: 0% ~ 0.008%, containing, having a chemical composition the balance being Fe and impurities, wherein the chemical composition is represented by the following formula (5), the following equation (6) and the following formula (7) in slab satisfying the hot rolling process for manufacturing a hot-rolled sheet is subjected to hot rolling, 　after the hot rolling step, the cold rolling to the hot-rolled sheet a cold rolling step of producing a cold-rolled sheet having a thickness of 0.05 mm ~ 0.40 mm by applying, 　after said cold rolling step, the annealing finish on the cold-rolled sheet And to finish annealing process has, 　in the cold rolling step, solid solution strengthening parameter represented by the average crystal grain size D of the hot rolled sheet prior to the cold rolling ([mu] m) and the following formula (8) and R satisfies the following equation (9), 　in the process of heating the cold-rolled sheet in the finish annealing step, keep 10 ~ 300 s at a constant temperature in the range temperature of 550 ° C. ~ 700 ° C. of the cold-rolled sheet method for producing a non-oriented electrical steel sheet, characterized in that. 　　0.50 ≦ Al / (Si + Al + 0.5 × Mn) ≦ 0.83 　　(5) 1.28 ≦ Si + Al / 2 + Mn / 4 + 5 × P ≦ 3.90 　　(6) 4.0 ≦ Si + Al + 0.5 × Mn ≦ 7. 0 　　(7) R = Si + Al / 2 + Mn / 4 + 5 × P (8) [Equation 1]

[Claim 3]
　Between the cold rolling step and the hot rolling process, a non-oriented electrical of claim 2, further comprising a hot-rolled sheet annealing step of subjecting the hot-rolled sheet annealing to the hot rolled plate method of manufacturing a steel plate.