Technical field
[0001]
The present invention relates to a non-oriented electrical steel sheet.
The present application, to 01 May 16, 2017, claiming priority based on Japanese Patent Application No. 2017-005212, filed in Japan, the contents of which are incorporated here.
BACKGROUND
[0002]
　In recent years, attention has been focused on global environmental problems, a need for a commitment to energy conservation, have been increasing more. Among them, high-efficiency electrical equipment, there has been a strong demand in recent years. Therefore, even in the non-oriented electrical steel sheet is widely used as a core material such as a motor or a generator or a transformer, demand for improvement in the magnetic properties are further strengthened. Recently, electric vehicles and motors and generators for hybrid vehicle efficiency progresses, and, in the motor compressor, the tendency is remarkable.
[0003]
　In order to improve the magnetic properties of non-oriented electrical steel sheet, increasing the electrical resistance of the steel sheet by adding alloying elements in the steel, it is effective to reduce the eddy current loss. Therefore, for example, as disclosed in Patent Documents 1 and 2 below, Si, Al, and addition of an element having an effect of increasing the electrical resistance such as Mn, reduction of improving the magnetic properties (iron loss, it has been performed to achieve an increase) in the magnetic flux density.
CITATION
Patent Document
[0004]
Patent Document 1: WO 2016/027565
Patent Document 2: Japanese Patent 2016-130360 JP
Patent Document 3: WO 2016/136095
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　When considering that the same content (mass%) is added alloy elements, except for the large P of adverse cold rolling property, Si is easily increase the electrical resistance, the reduction of iron loss it is an effective element. Therefore, in Patent Document 1 discloses that the Si content is 6 wt% or less, in the above-described Patent Document 2 discloses that a Si-content 5.0 wt% or less, Patent Document 3, it is disclosed to the Si content of 8.0 mass% or less.
　In Patent Document 1 and Patent Document 2, the Al content is set to 0.0050% or less, by increasing the electrical resistance in Si and Mn, it is also disclosed to reduce the iron loss.
[0006]
　However, as a result of inventors studied, the steel plate shown in Patent Documents 1 to 3, W 10/400 reduction of high-frequency iron loss, such as was not sufficient. The reason is that, although the reduction of the high-frequency iron loss is essential highly alloyed, in Patent Documents 1 to 3 not been studied high-frequency iron loss, the alloy amount required for the high-frequency iron loss reduction and the lower limit value, Si, Al, since the allocation of the proper amount of Mn is not taken into consideration, W 10/400 reduction of high-frequency iron loss such as is considered not sufficient.
[0007]
　The present invention was made in view of the above problems. An object of the present invention, the cold rolling property is good, the magnetic properties, particularly excellent high-frequency iron loss, is to provide a non-oriented electrical steel sheet.
Means for Solving the Problems
[0008]
　In order to solve the above problems, the present inventors have conducted extensive studies. As a result, (i) to the Al content is less than a predetermined value, (ii) contributes to the increase of the electrical resistance, that the Mn adversely less to cold rolling property is included together with Si, and (iii) la, Ce, Pr, possible to further contain one or more and the Ti of Nd, by, while ensuring a good cold rollability, improving the magnetic characteristics by preventing a decrease in grain growth to obtain a knowledge that it is possible, thereby completing the present invention.
　Summary of the completed invention based on the above findings, as follows.
[0009]
(1) non-oriented electrical steel sheet according to one embodiment of the present invention, the chemical composition, in mass%, C: 0%, greater than 0.0050% or less, Si: 3.0% ~ 4.0%, Mn : 1.2% ~ 3.3%, P: 0% greater than, less than 0.030%, S: 0% greater than, 0.0050% or less, sol. Al: 0%, greater than 0.0040% or less, N: 0%, greater than 0.0040% or less, La, Ce, Pr, Nd 1 or more kinds of 0.0005% in total - 0.0200% , Ca: 0.0005% ~ 0.0100%, Ti: 0.0005% ~ 0.0100%, Sn: 0% ~ 0.10%, Sb: 0% ~ 0.10%, Mg: 0% ~ 0.0100%, contain, the balance being Fe and impurities, Si-0.5 × Mn: is 2.0% or more, Si + 0.5 × Mn: at 3.8% or more.
[0010]
(2) In the non-oriented electrical steel sheet according to (1), the chemical composition, Sn: 0.005% ~ 0.10%, Sb: 0.005% ~ 0.10%, selected from 1 it may contain species or two.
[0011]
(3) In the non-oriented electrical steel sheet according to (1) or (2), the chemical composition, Mg: may contain 0.0005% - 0.0100%.
Effect of the invention
[0012]
　According to this aspect of the present invention, good cold rollability, and is non-oriented electrical steel sheet having excellent magnetic characteristics can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
FIG. 1 is a diagram of the structure of non-oriented electrical steel sheet schematically showing according to an embodiment of the present invention.
Is a diagram showing an example of the flow of FIG. 2] The method for producing a non-oriented electrical steel sheet according to the embodiment.
DESCRIPTION OF THE INVENTION
[0014]
　With reference to the drawings will be described in detail one form of a preferred embodiment of the present invention. In the present specification and drawings, components having substantially the same function and structure, and repeated explanation is omitted referring to the figures.
[0015]
(Non-oriented Electromagnetic steel sheets)
　in the non-oriented electrical steel sheet, as described prior, in order to reduce high frequency iron loss, in general, the electrical resistance of the steel sheet by containing alloy elements in steel raised, to reduce the eddy current loss. Here, when considering that the inclusion of alloying elements of the same content (mass%), Si is because easy to increase the electrical resistance, which is an element effective in reducing iron loss. However, the result of the examination by the present inventors, when the Si content exceeds 4.0 mass%, it has been found that cold rolling of non-oriented electrical steel sheet is remarkably lowered.
[0016]
　Further, Al is also an alloying element indicating the increasing effect of the same electrical resistance and the Si. However, the result of the examination by the present inventors, Al also revealed that lowering the cold rolling property as with Si. Also, the Al content is increased, the magnetic properties tend to decrease hysteresis loss is deteriorated. Therefore, in the non-oriented electrical steel sheet, be contained a large amount of Al as an alloying element is difficult. In non-oriented electrical steel sheet, in order to suppress the deterioration of the magnetic properties due to the deterioration of the hysteresis loss, Al content is preferably less. On the other hand, the present inventors have conducted extensive studies, the steel having a reduced Al content decreases the grain growth, the magnetic properties became also clear that decrease.
[0017]
　The present inventors have found that even when a reduced Al content, it is possible to suppress a decrease in grain growth, were intensively studied capable of improving both the cold rolling resistance and magnetic properties methods. As a result, the Mn adversely less to cold rolling property on which contains together with Si, further effective La, Ce, Pr, one or more and Ti of Nd be contained in a complex manner It was found that there.
[0018]
　In the following, with reference to FIG. 1, the non-oriented electrical steel sheet according to an embodiment of the present invention (non-oriented electrical steel sheet according to the present embodiment) will be described in detail.
[0019]
　Figure 1 is a diagram of the structure of non-oriented electrical steel sheet according to the present embodiment shown schematically. Non-oriented electrical steel sheet 10 according to this embodiment, as schematically shown in FIG. 1, it has a base iron 11 having a predetermined chemical composition. Non-oriented electrical steel sheet according to the present embodiment may comprise only the base steel 11, but the surface of the base steel 11 preferably further has an insulating coating 13.
[0020]
　In the following, first, the base steel 11 of the non-oriented electrical steel sheet 10 according to the present embodiment will be described in detail.
[0021]

　base iron 11 of the non-oriented electrical steel sheet 10 according to this embodiment, by mass%, C: 0%, greater than 0.0050% or less, Si: 3.0% ~ 4. 0%, Mn: 1.2% ~ 3.3%, P: 0% greater than, less than 0.030%, S: 0% greater than, 0.0050% or less, sol. Al: 0%, greater than 0.0040% or less, N: 0%, greater than 0.0040% or less, La, Ce, Pr, Nd 1 or more kinds of 0.0005% in total - 0.0200% , Ca: 0.0005% ~ 0.0100% , Ti: 0.0005% ~ 0.0100%, Sn: 0% ~ 0.10%, Sb: 0% ~ 0.10%, Mg: 0% ~ containing 0.0100% the balance being Fe and impurities, Si content, and, by using the Mn content, when calculating the value represented by "Si + 0.5 × Mn" 3.8 not less than%, Si content, and, by using the Mn content, when calculating the value represented by "Si-0.5 × Mn", is 2.0% or more.
[0022]
　Further, the base iron 11 of the non-oriented electrical steel sheet 10 according to this embodiment, Sn: 0.005% to 0.10%, Sb: at least one selected from 0.005% to 0.10% it is preferable to.
[0023]
　Further, the base iron 11 of the non-oriented electrical steel sheet 10 according to this embodiment, Mg: preferably contains 0.0005% - 0.0100%.
[0024]
　In the following, the reason why the chemical composition of the base steel 11 of the present embodiment is defined as above, will be described in detail. In the following, unless otherwise specified, according to the chemical composition "%" represents "% by mass".
[0025]
[C: 0%, greater than 0.0050% or
　less] C (carbon), together with an element which is inevitably contained, an element that causes iron loss deterioration (increase in iron loss). If the C content exceeds 0.0050%, the iron loss deteriorates in non-oriented electrical steel sheet is produced, it is impossible to obtain good magnetic properties. Accordingly, in the non-oriented electrical steel sheet according to the present embodiment, the C content is 0.0050% or less. C content is preferably not more than 0.0040%, more preferably 0.0030% or less.
　C content is preferably as small as possible, C is an element inevitably contained, the lower limit is 0 percent. Further, when the C content to try to reduce than 0.0005%, a significant increase in cost. Therefore, C content may be 0.0005% or more.
[0026]
[Si: 3.0% ~
　4.0%] Si (silicon) elevates the electrical resistance of the steel to reduce the eddy current loss, which is an element to improve the high-frequency iron loss. Also, Si, since a large solid-solution strengthening ability is an effective element in increasing the strength of non-oriented electrical steel sheet. In non-oriented electrical steel sheet, high strength, it is necessary from the viewpoint of suppressing deformation and fatigue fracture suppression at the time of high speed rotation of the motor. In order to sufficiently exert such effects, it is necessary to the Si content 3.0% or more. Si content is preferably 3.1% or more, more preferably 3.2% or more.
　On the other hand, when the Si content exceeds 4.0%, the workability is remarkably deteriorated, it becomes difficult to implement a cold-rolled, steel sheet or broken in the course of cold rolling (i.e. , cold rolling is lowered). Therefore, Si content is 4.0% or less. Si content is preferably not more than 3.9%, more preferably at most 3.8%.
[0027]
[Mn: 1.2% ~
　3.3%] Mn (manganese) is to reduce the eddy current loss by increasing electrical resistance, which is an element effective for improving the high-frequency iron loss. Moreover, Mn, although solid-solution strengthening ability than Si is small, without deteriorating the workability, an element which can contribute to higher strength. In order to sufficiently exhibit the effect, it is necessary that the Mn content is 1.2% or more. Mn content is preferably 1.3% or more, more preferably 1.4% or more, further preferably 1.5% or more.
　On the other hand, when the Mn content exceeds 3.3%, a reduction in magnetic flux density becomes remarkable. Therefore, Mn content is 3.3% or less. Mn content is preferably not more than 3.2%, more preferably not more than 3.1%, more preferably not more than 3.0%.
[0028]
[P: 0% greater, than
　0.030%] P (phosphorus), in Si and Mn content is more high alloy steel, is an element significantly workability is deteriorated difficult cold rolling. Accordingly, P content is less than 0.030% or. P content is preferably not more than 0.020% or, more preferably, 0.010% or less.
　P content is better the less, P is an element inevitably contained, the lower limit is 0 percent. When the P content to try to less than 0.001% leads to a significant increase in cost. Therefore, it is preferable that the lower limit of 0.001% or more. More preferably 0.002% or more.
[0029]
[S: 0%, greater than 0.0050% or
　less] S (sulfur) is an element which is inevitably contained. Further, S is increase the iron loss by forming fine precipitates of MnS, which is an element degrading the magnetic properties of non-oriented electrical steel sheet. Therefore, S content should be 0.0050% or less. S content is preferably not more than 0.0040%, more preferably not more than 0.0035%.
　S content is preferably as small as possible, S is an element inevitably contained, the lower limit is 0 percent. When the S content to try to reduce than 0.0001% leads to a significant increase in cost. Thus, S content is preferably made 0.0001% or more.
[0030]
[Sol. Al: 0%, greater than 0.0040% or less]
　Al (aluminum), when a solid solution state in the steel, to reduce the eddy current loss by increasing electrical resistance of the non-oriented electrical steel sheet, high-frequency iron loss it is an element to improve. However, in the non-oriented electrical steel sheet according to the present embodiment, positively to contain Mn is an element to increase the electric resistance without deteriorating the workability than Al. Therefore, it is not necessary to contain actively Al. In addition, sol. When Al (acid soluble Al) content exceeds 0.0040% fine nitrides in the steel is precipitated to inhibit grain growth in the hot-rolled sheet annealing and finish annealing, the magnetic properties deteriorate . Therefore, sol. Al content, and 0.0040%. sol. Al content is preferably 0.0030% or less, more preferably 0.0020%.
　Meanwhile, Al is an element inevitably contained, the lower limit is 0 percent. In addition, sol. When the Al content to try to reduce than 0.0001% leads to a significant increase in cost. Therefore, sol. Al content may be 0.0001% or more.
[0031]
[N: 0%, greater than 0.0040% or
　less] N (nitrogen) is an element which is inevitably contained. Further, N represents, to form fine nitride in steel increases the iron loss, is an element which deteriorates the magnetic properties of non-oriented electrical steel sheet. Therefore, N content is required to be 0.0040%. N content is preferably not more than 0.0030% or, more preferably 0.0020%.
　Meanwhile, N is an element inevitably contained, the lower limit is 0 percent. Moreover, the N content is better the less, when the N content to try to reduce than 0.0001% leads to a significant increase in cost. Therefore, N content may be 0.0001% or more. More preferably 0.0003% or more.
[0032]
[Ti: 0.0005% ~
　0.0100%] Ti (titanium) is inevitably contained in raw materials of the Mn and Si. Element Ti is the C in the base steel, N, O, etc. combine with TiN, TiC, to form a fine precipitate, such as Ti oxides, deteriorating the magnetic properties to inhibit grain growth during annealing it is. Therefore, conventionally, in order to minimize the Ti content in the base steel, it has been practiced to use a raw material of highly purified Mn and Si.
　However, the present inventors have conducted studies, La described below, Ce, 1 kind of Pr and Nd or two or more, by compositely be contained together with Ti, the growth of crystal grains during annealing without inhibition it was found to be capable of retaining the grain growth. Although the cause is not yet clear, the resulting TiN, TiC, fine precipitates such as Ti oxides La, Ce, are coarsened by combined with one or more compounds of Pr and Nd, It does not inhibit the growth of crystal grains, presumably because became larger precipitates. That will reduce the fine precipitates that inhibit grain growth by coarse precipitates are produced, it is considered to decrease the grain growth is suppressed.
　Furthermore, conventionally, in order to minimize the Ti content in the base steel, Ti by the high purity of the raw materials has been achieved, the La, Ce, to contain one or more of Pr and Nd since it is possible to avoid adverse effects, it becomes better without achieved excessive purity of the raw materials. As a result, it is possible to manufacture at a lower cost higher performance non-oriented electrical steel sheet.
[0033]
　The non-oriented electrical steel sheet according to the present embodiment, La, Ce, by containing one or more of Pr and Nd, the grain growth even Ti is mixed from raw material can be ensured. Therefore, it is not necessary to make an excessive purity of the raw materials. Consider using Mn or Si raw material containing Ti in terms of cost, Ti content is 0.0005% or more. However, if the Ti content exceeds 0.0100%, the maximum amount of La to be acceptable, Ce, even be contained one or more of Pr and Nd, to prevent the adverse effect of Ti It becomes difficult. Therefore, Ti content is 0.0005% or more and 0.0100% or less. La, Ce, the effect of improving the grain growth due to be compositely contained with one or more of Pr and Nd reliably expressed, and in order to achieve cost reduction, Ti content, preferably 0.0015% or more, or less 0.0080%, more preferably 0.0025% or more, 0.0060% or less.
[0034]
[La, Ce, Pr and Nd 1, two or more of:
　0.0005% - 0.0200% in total] La, Ce, Pr, Nd is coarse sulfide combines with S, sulfates or to suppress the precipitation of fine MnS by forming both of these, is an element which promotes grain growth during annealing. Moreover, La, Ce, Pr, Nd is, TiN is generated due to Ti, TiC, fine precipitates such as Ti oxides, La, Ce, Pr, sulfides Nd or sulfates or both of these by complex precipitated improve grain growth in an element that improves the magnetic properties. In order to obtain such an effect, La, Ce, 1 or two or more of the content of Pr and Nd, it is necessary that the total is less than 0.0005%. Meanwhile, La, Ce, when one or two or more of the content of Pr and Nd exceeds 0.0200% in total, the upper coarsening effect of fine precipitates such as described above is saturated, economical It is not preferable because it is disadvantageous to. Accordingly, La, Ce, Pr and one or more of the content of Nd is a 0.0200% or less in total. La, Ce, 1 or two or more of the content of Pr and Nd is 0.0010% or more preferably in total not more than 0.0150%, more preferably in total 0.0020% or more, 0. it is 0,100% or less.
[0035]
[Ca: 0.0005% ~
　0.0100%] Ca (calcium) is to suppress the precipitation of that the fine MnS which combines with S to form a coarse compound to promote grain growth in annealing it is an element. Moreover, La, Ce, Pr, the combined content of one or more of Nd, is an element effective to avoid nozzle clogging of the resulting oxide during continuous casting. To obtain such effects, Ca content is required to be 0.0005% or more. Preferably, it is 0.0010% or more.
　On the other hand, if the Ca content exceeds 0.0100%, the grain growth improving effect and the effect of suppressing nozzle clogging in the above is saturated, which is economically disadvantageous. Therefore, Ca content, and 0.0100% or less. Ca content is preferably not more than 0.0080%, more preferably 0.0060% or less.
[0036]
[Sn:
0% ~ 0.10%] [Sb: 0% ~
　0.10%] Sn (tin) and Sb (antimony), by segregated on the surface to prevent oxidation and nitridation during annealing, low it is a useful element to ensure the core loss. Accordingly, in the non-oriented electrical steel sheet according to the present embodiment, in order to obtain the above effect, at least one of Sn or Sb, it may be contained in the base steel. In order to sufficiently exhibit the above effect, the content of Sn or Sb, it is preferable to respectively 0.005% or more. More preferably 0.010% or more.
　On the other hand, if the content of Sn or Sb is more than 0.10%, respectively, there is a possibility that the ductility of the steel matrix is difficult to cold rolling reduction. Therefore, the content of Sn or Sb, even if to be contained, it is preferable that 0.10%, respectively less. More preferably, 0.05% or less, respectively.
　Sn, Sb is any element, since it is not always necessary to contain, the lower limit is 0%.
[0037]
[Mg: 0% ~
　0.0100%] Mg (Makuneshiumu) combines with S to form a coarse compound. When coarse compounds of Mg and S are formed, is suppressed precipitation of fine MnS, the crystal grain growth during annealing is promoted, it is advantageous to ensure a low core loss. Accordingly, in the non-oriented electrical steel sheet according to the present embodiment, in order to obtain the above effect, it may contain Mg. In order to sufficiently exhibit the effect, the Mg content is preferably set to 0.0005% or more. On the other hand, if the Mg content exceeds 0.0100%, the effect of improving the grain growth property is saturated, so is economically disadvantageous undesirable. Thus, Mg content is preferably set to 0.0100% or less. In case of containing Mg in the base steel, Mg content is more preferably is 0.0050% or less.
　Mg is optional element, since it is not always necessary to contain, the lower limit is 0%.
[0038]
　Non-oriented electrical steel sheet according to the present embodiment includes the above elements, and the balance basically in that it consists of Fe and impurities. However, in the non-oriented electrical steel sheet according to the present embodiment, other than the elements described above Ni (nickel), Cr (chromium), Cu (copper), and may further contain an element such as Mo (molybdenum) . Also contain these elements of 0.50% or less, respectively, the effect of the non-oriented electrical steel sheet according to the present embodiment is not impaired.
[0039]
　Further, in addition to the above elements, Pb (lead), Bi (bismuth), V (vanadium), As (arsenic), element may further contain such B (boron). Even if these elements are included 0.0050%, respectively, the effect of the non-oriented electrical steel sheet according to the present embodiment is not impaired.
[0040]
　Non-oriented electrical steel sheet according to the present embodiment, after controlling the content of each element as described above, requires that the Si content and Mn content and is controlled so as to satisfy a predetermined relationship is there.
[0041]
[Si + 0.5 × Mn: 3.8 % or more]
　iron loss, especially the non-oriented electrical steel sheet according to the present embodiment W aims 10/400 frequency iron loss reducing (improving) as in the case , it is effective to increase the electrical resistance of the high alloyed steel sheets. Specifically, by incorporating Si, Mn, as Si + 0.5 × Mn is 3.8% or more, it is possible to further reduce the high frequency iron loss. Therefore, the Si + 0.5 × Mn and 3.8% or more. Si + 0.5 × Mn is preferably 3.9% or more, more preferably 4.0% or more, more preferably 4.4% or more.
　Substantial upper limit of the Si + 0.5 × Mn is a value calculated from the upper limit of the content of Si and Mn.
[0042]
: [Si-0.5 × Mn 2.0 % or more]
　In non-oriented electrical steel sheet according to the present embodiment, La, which is contained, Ce, Pr, Nd, Ca is, S as sulfide or oxysulfide fixed. In this case, the accelerated oxidation or nitriding of the surface of the steel sheet, magnetic properties may be deteriorated.
　However, by a Si-0.5 × Mn ≧ 2.0, it is possible to suppress the deterioration of the magnetic properties. The reason is not clear, by a Si-0.5 × Mn ≧ 2.0, when the heating of the finishing annealing, dense SiO 2 thin oxide layer having occurs easily on the surface of the steel sheet, the finish annealing soaking presumably because oxidation and nitridation of a thermal process is suppressed.
[0043]
　Moreover, Si is a ferrite phase formation promoting elements (so-called ferrite former element). On the other hand, Mn is an austenite phase formation promoting elements (so-called austenite former element). Thus, depending on the content of each Si and Mn, the non-oriented electrical steel sheet metal structure changes, non-oriented electrical steel sheet, or a component system having a transformation point, and no component of the transformation point or it becomes. The non-oriented electrical steel sheet according to the present embodiment, it is required to appropriately increase the average crystal grain size in the base steel, be no component of the transformation point, in order to increase the crystal grain size It becomes an effective means of. Therefore, so as not to have component system the transformation point, the content of each of Si and Mn, it is preferable to satisfy a predetermined relationship.
[0044]
　According to the studies of the present inventors, (in other words, the effect of canceling the ferrite phase formation promoting ability) austenite formation promoting ability of Mn it is believed to 0.5 times the ferrite phase formation promoting ability of Si. Therefore, equal amounts of ferrite phase formation promoting ability in the present embodiment, based on the content of Si, can be expressed as "Si-0.5 × Mn".
[0045]
　If the value of the Si-0.5 × Mn is less than 2.0%, the non-oriented electrical steel sheet, it becomes a component system having a transformation point. As a result, there is a concern that the steel sheet of the metal structure during the process of producing high-temperature treatment is not a ferrite single phase, the magnetic properties of non-oriented electrical steel sheet is lowered. Therefore, the value of the Si-0.5 × Mn is 2.0% or more. Preferably is 2.1% or more.
　On the other hand, the upper limit of the Si-0.5 × Mn is particularly not intended to define, from the range of the Si content and the Mn content of the non-oriented electrical steel sheet according to the present embodiment, Si-0.5 × the value of Mn can not be more than 3.4%. Therefore, the upper limit of the Si-0.5 × Mn is essentially made 3.4%.
[0046]
　Although the chemical composition of the base steel in the non-oriented electrical steel sheet according to the present embodiment has been described in detail.
[0047]
　The chemical composition of the base steel in the non-oriented electrical steel sheet, in the case of post-measure, it is possible to utilize various known measurement methods. For example, spark discharge optical emission spectrometry, ICP emission spectrometry, and further, C, combustion in the case of measuring accurately the S - infrared absorption method, O, in the case of N to accurately measure the inert gas fusion - Red outer absorption method / thermal conductivity method may be appropriately used.
[0048]

　thickness of the base steel 11 in the non-oriented electrical steel sheet 10 according to the present embodiment (the thickness in Fig. 1 t), in order to reduce high-frequency iron loss by reducing the eddy current loss , is preferably not greater than 0.40 mm. On the other hand, if the thickness t of the base steel 11 is less than 0.10mm, there is a possibility that the sheet passage of annealing line for sheet thickness is thin becomes difficult. Therefore, the thickness t of the base steel 11 in the non-oriented electrical steel sheet 10, or 0.10 mm, is preferably not greater than 0.40 mm. Thickness t of the base steel 11 in the non-oriented electrical steel sheet 10, more preferably, 0.15 mm or more and 0.35mm or less.
[0049]
　Although the base steel 11 of the non-oriented electrical steel sheet 10 according to this embodiment has been described in detail.
[0050]

　Next, the it is preferred insulating coating 13 which non-oriented electrical steel sheet 10 of the present embodiment has will be described briefly.
[0051]
　In order to improve the magnetic properties of non-oriented electrical steel sheet, it is important to reduce the iron loss. Iron loss, and a eddy current loss and hysteresis loss. By the surface of the base steel 11 providing the insulating film 13, it becomes possible to reduce the eddy current loss of the core to inhibit conduction between the electromagnetic steel plates stacked as core, of the non-oriented electrical steel sheet 10 Furthermore it is possible to improve the practical magnetic properties.
[0052]
　Here, the insulating film 13 to the non-oriented electrical steel sheet 10 according to this embodiment is provided, as long as it can be used as an insulating film of non-oriented electrical steel sheet, is not particularly limited, a known insulating film it is possible to use. As such an insulating film, for example, an inorganic material as a main component, may be mentioned more complex insulation coating containing an organic material. Here, the composite insulating coating, for example, chromic acid metal salts, phosphoric acid metal salts or colloidal silica, Zr compound, as a main component at least one of inorganic Ti compound or the like, particles of fine organic resin is dispersed it is there insulating coating. In particular, from the viewpoint of the production time of reducing environmental burden has increased with recent demand, the coupling agent of the phosphoric acid metal salt and Zr, or Ti, or an insulating film using these carbonates or ammonium salts as starting materials preferably used.
[0053]
　Adhesion amount of the above-mentioned insulating coating 13 is not particularly limited, for example, 0.1 g / m per side 2 or 2.0 g / m 2 preferably be on the order or less, per side 0.3g / m 2 or more 1.5 g / m 2 and more preferably at most. By forming the insulating film 13 so that the above-described deposition amount, it becomes possible to retain good uniformity. The coating weight of the insulation coating 13, in the case of post-measure, it is possible to use various known measurement methods. Adhesion amount of the insulating coating 13, for example, a non-oriented electrical steel sheet 10 forming the insulating film 13 to remove only the insulating film 13 by immersing the hot alkaline solution, calculated from the mass difference before and after removal of the insulating coating 13 it is possible to.
[0054]

　non-oriented electrical steel sheet 10 according to this embodiment, by having the above structure, exhibits excellent magnetic properties. Here, various magnetic properties of showing the non-oriented electrical steel sheet 10 according to this embodiment, Epstein method, defined in JIS C2550, veneer magnetic property measuring method specified in JIS C2556 (Single Sheet Tester: SST ) to with reference, it is possible to measure.
[0055]
　Above with reference to FIG. 1, the non-oriented electrical steel sheet 10 according to this embodiment has been described in detail.
[0056]
(Method of manufacturing the non-oriented electrical steel sheet)
　Next, referring to FIG. 2, a preferred method for producing a non-oriented electrical steel sheet 10 according to the present embodiment as described above will be briefly described.
　Figure 2 is a diagram showing an example of the flow of the manufacturing method of the non-oriented electrical steel sheet according to the present embodiment.
[0057]
　In the method of manufacturing the non-oriented electrical steel sheet 10 according to this embodiment, with respect to the steel ingot having a predetermined chemical composition as described above, hot rolling, hot-rolled sheet annealing, pickling, cold rolling, finish to implement the annealing in order. In the case of forming the insulating film 13 on the surface of the base steel 11, formation of the insulating film after the final annealing is performed. Hereinafter, each step carried out by the method for producing a non-oriented electrical steel sheet 10 according to the present embodiment will be described in detail.
[0058]

　In the method of manufacturing the non-oriented electrical steel sheet according to the present embodiment, first, heating a steel ingot (slab) having the above chemical composition, the hot rolled against the heated steel ingot go and get the hot-rolled steel sheet (step S101). The heating temperature of the steel ingot when subjected to hot rolling is not particularly intended to define, for example, preferably set to 1050 ℃ ~ 1300 ℃. The heating temperature of the steel ingot is more preferably 1050 ℃ ~ 1250 ℃.
　As for the thickness of the hot-rolled steel sheet after hot rolling is not particularly intended to define, in consideration of the final thickness of the base steel, e.g., is preferably about 1.6 mm ~ 3.5 mm . Hot rolling step is preferably ended in the temperature of the steel sheet is in the range of 700 ℃ ~ 1000 ℃. End temperature of hot rolling is more preferably 750 ℃ ~ 950 ℃.
[0059]

　After the hot rolling, hot-rolled sheet annealing (annealing for hot-rolled steel sheet) is performed (step S103). In the case of continuous annealing, to the hot-rolled steel sheet, for example, at 750 ° C.-1200 ° C., it is preferred to carry out the annealing comprising soaking 10 seconds to 10 minutes. Also, in the case of box annealing, with respect to hot-rolled steel sheet, for example, at 650 ° C.-950 ° C., it is preferred to carry out the annealing comprising soaking 30 minutes to 24 hours.
　Although the magnetic properties as compared with the case of carrying out the hot-rolled sheet annealing process will be slightly inferior, to reduce costs, it may be omitted hot-rolled sheet annealing step.
[0060]

　after the hot rolled sheet annealing step, the pickling is carried out (step S105). Thus, formed on the surface of the steel sheet during hot-rolled sheet annealing, the scale layer consisting mainly of oxide are removed. If hot rolled sheet annealing is box annealing, from the viewpoint of descaling property, pickling step is preferably carried out before hot-rolled sheet annealing.
[0061]

　After the pickling step (if hot-rolled sheet annealing is carried out in box annealing, when the after hot-rolled sheet annealing step also.), The relative hot rolled steel sheet, cold rolling is performed (step S107). In cold rolling, at a reduction ratio as final thickness is less than 0.40mm or 0.10mm of the base steel, it is preferable to roll the pickled plate removed scales.
[0062]

　After the cold rolling step, to cold-rolled steel sheet obtained by cold rolling, finish annealing is performed (step S109). In the method of manufacturing the non-oriented electrical steel sheet according to the present embodiment, the Atsushi Nobori process of the final annealing, it is preferable that the rapid heating. By performing rapid heating of the temperature raising process, the base steel 11, advantageously recrystallized texture to magnetic properties is formed. If the Atsushi Nobori process of the final annealing and rapid heating, final annealing is preferably performed by continuous annealing.
[0063]
　Specifically, in the heating process, it is preferable that the average heating rate between 1 ° C. / sec ~ 2000 ° C. / sec. Moreover, the atmosphere in the furnace during heating, H 2 H ratio of from 10 vol% to 100 vol% 2 and N 2 mixed atmosphere (i.e., H 2 + N 2 and = 100 vol%), the atmosphere it is preferable that the dew point and 30 ° C. or less. The average heating rate is more preferably in the 5 ° C. / sec - 1500 ° C. / sec, H in the atmosphere 2 ratio of is more preferably from 15 vol% to 90 vol%, dew point of the atmosphere, more preferably, it is not 20 ° C. or less, still more preferably 10 ° C. or less. The average heating rate above, for example, by or using direct heating or radiant tube or using an indirect heating using a known heating method such as electrical heating or induction heating, etc. to others in the case of heating by gas burning , it can be realized.
[0064]
　The soaking process after the heating process, the soaking temperature, and 700 ° C.-1100 ° C., soaking time, 1 second to 300 seconds, atmosphere, H 2 ratio of 10 vol% to 100 vol% H is 2 and N 2 mixed atmosphere (i.e., H of 2 + N 2 = 100 vol%), and it is preferable that the dew point of the atmosphere to 20 ° C. or less. Soaking temperature is more preferably from 750 ° C.-1050 ° C., H in the atmosphere 2 ratio of is more preferably from 15 vol% to 90 vol%, dew point of the atmosphere, more preferably, 10 ° C. or less, still more preferably 0 ℃ less.
[0065]
　In the cooling process after soaking process, it is preferable to cool the average cooling rate to 200 ° C. or less at 1 ° C. / sec ~ 50 ° C. / sec. The average cooling rate is more preferably from 5 ° C. / sec ~ 30 ° C. / sec.
[0066]
　According to the manufacturing method including the steps described above, it is possible to produce a non-oriented electrical steel sheet 10 according to this embodiment.
[0067]

　After the final annealing, if necessary, the formation process of the insulating coating are performed (step S111). The step of forming the insulating film, is not particularly limited, using known insulation coating treatment solution as described above may be carried out coating and drying of the treatment liquid by a known method.
[0068]
　Surface of the base steel which insulating film is formed, prior to applying the treatment solution, etc. or by degreasing alkali, hydrochloric, sulfuric, etc. pickling treatment with phosphoric acid and the like, may be subjected to any pretreatment may be the surface remains after annealing finish without performing these pre-treatment.
[0069]
　Above with reference to FIG. 2, a method for manufacturing the non-oriented electrical steel sheet according to the present embodiment has been described in detail.
Example
[0070]
　Hereinafter, while showing Examples, the non-oriented electrical steel sheet according to the present invention will be specifically described. Examples shown below is a mere example of a non-oriented electrical steel sheet according to the present invention, the non-oriented electrical steel sheet according to the present invention is not limited to the following examples.
[0071]
(Experimental Example 1)
　contains a composition shown in Table 1 below, a steel slab balance being Fe and impurities, was heated to 1150 ° C., was rolled to 2.0mm thick by hot rolling. Subsequently, the hot rolled steel sheet in the annealing furnace of a continuous annealing type, after the soaking temperature is soaking time at 1000 ° C. was hot-rolled sheet annealing of 40 seconds, of 0.25mm thickness by performing cold rolling cold It was rolled steel sheet. The cold-rolled steel sheet to, soaking time at a soaking temperature of 1000 ° C. is performed finish annealing of 15 seconds. Thereafter, further mainly of phosphoric acid metal salts, by applying and baking a solution containing an emulsion of acrylic resin on both surfaces of the steel sheet to produce a non-oriented electrical steel sheet by forming a composite insulating coating.
[0072]
　The above finish annealing, the temperature raising process, the soaking process, a dew point of -30 ° C., H 2 ratio of 30% by volume of H 2 and N 2 were carried out in a mixed atmosphere of. The average heating rate of 20 ° C. / sec in the temperature elevation process at the time of final annealing, the average cooling rate in the cooling process was 20 ° C. / sec. After the finish annealing was cooled to 200 ℃ or less.
[0073]
　In Table 1, "Tr." Represents that which does not contain intended the appropriate elements. The underlined indicates that is out of the scope of the present invention.
[0074]
　Then, for each of the non-oriented electrical steel sheet produced by Epstein method specified in JIS C2550, the magnetic flux density B 50 and the iron loss W 10/400 was assessed. The results obtained are shown together in Table 1.
[0075]
[Table 1]

[0076]
　As is apparent from Table 1, La, Ce, total content and the Ca content of Pr and Nd is the test number 1, Ti content outside the lower than the range of the present invention deviated higher than the present invention range test No. 8, La, Ce, the total content of Pr and Nd test No. 11 deviated to lower than the present invention range, iron loss and magnetic flux density was inferior. Also, Test No. 9 for Ca content outside the lower than the range of the present invention, since the nozzle clogging occurs during continuous casting, abandoned production. On the other hand, Test Nos 2,3,4,5,6,7 and 10 are within the scope of the chemical composition of the steel sheet present invention, and the iron loss and magnetic flux density were both excellent.
[0077]
(Experimental Example 2)
　containing the composition shown in Table 2, the steel slab and the balance being Fe and impurities, was heated to 1150 ° C., was rolled to 2.0mm thick by hot rolling. Then, after annealing the hot rolled sheet in annealing furnace of a continuous annealing formula under the conditions of hot-rolled steel sheet soaking temperature soaking time of 40 seconds at 1000 ° C., of 0.25mm thickness by performing cold rolling cold to obtain a rolled steel sheet. Then, to this cold-rolled steel sheet, soaking time at a soaking temperature of 1000 ° C. is carried out finish annealing under conditions of 15 seconds. Thereafter, further mainly of phosphoric acid metal salts, by applying and baking a solution containing an emulsion of acrylic resin on both surfaces of the steel sheet to produce a non-oriented electrical steel sheet by forming a composite insulating coating.
[0078]
　Here, finish annealing the above, in the heating process and the soaking process, dew point is -30 ° C., H 2 ratio of 20% by volume of H 2 and N 2 were carried out in a mixed atmosphere of. The average heating rate of 20 ° C. / sec in the temperature elevation process at the time of final annealing, the average cooling rate in the cooling process was 20 ° C. / sec. After the finish annealing was cooled to 200 ℃ or less.
[0079]
　In Table 2, the "Tr." Represents that which does not contain intended the appropriate elements. The underlined indicates that is out of the scope of the present invention.
[0080]
　Then, for each of the non-oriented electrical steel sheet produced by Epstein method specified in JIS C2550, the magnetic flux density B 50 and the iron loss W 10/400 was assessed. The results obtained are shown together in Table 2.
[0081]
[Table 2]

[0082]
　P content and test No. 14, deviated higher than the scope of the present invention, Test No. 23 deviated to be higher than the range of the Si content present invention, because of the break in the cold-rolling, could not magnetometry . Range in which the test numbers 12,13,15,16,18,19,20,24,25 chemical composition of the steel sheet present invention, and 26 is capable of cold rolling, the iron loss and magnetic flux density It was excellent. On the other hand, sol. Test Al content is out to enhance the scope of the present invention No. 17, sol. Iron loss was inferior as compared with Test No. 16 within the scope of the invention that are substantially the same composition except al. Further, Mn content Test No. 22 deviated to be higher than the range of the present invention was inferior and the iron loss and magnetic flux density. Further, Si-0.5 × Mn test No. 21 deviated to lower than the range of the present invention was inferior and the iron loss and magnetic flux density.
[0083]
(Experimental Example 3)
　containing the composition shown in the following Table 3, the steel slab balance being Fe and impurities, was heated to 1150 ° C., it was rolled to 2.0mm thick by hot rolling. Subsequently, the hot rolled steel sheet soaking temperature is 1000 ° C., it was annealed hot-rolled sheet in the annealing furnace of a continuous annealing expression under conditions soaking time of 40 seconds, of 0.25mm thickness by performing cold rolling cold to obtain a rolled steel sheet. Then, the cold-rolled steel sheet, the soaking temperature is 800 ° C., was finish annealing under conditions soaking time of 15 seconds. Then, as a main component a phosphoric acid metal salt, and coating and baking a solution containing an emulsion of acrylic resin on both surfaces of the steel sheet to produce a non-oriented electrical steel sheet by forming a composite insulating coating. Then, with respect to the steel sheets were subjected to stress relief annealing of 750 ° C. × 2 hr.
[0084]
　Here, finish annealing the above, in the heating process and the soaking process, dew point is -30 ° C., H 2 ratio of 20% by volume of H 2 and N 2 were carried out in a mixed atmosphere of. The average heating rate 15 ° C. / sec in the temperature elevation process at the time of final annealing, the average cooling rate in the cooling process was 15 ° C. / sec. After the finish annealing was cooled to 200 ℃ or less.
[0085]
　In Table 3, the "Tr." Represents that which does not contain intended the appropriate elements. The underlined indicates that is out of the scope of the present invention.
[0086]
　Then, for each of the non-oriented electrical steel sheet produced by Epstein method specified in JIS C2550, the magnetic flux density B 50 and the iron loss W 10/400 was assessed. The results obtained are shown together in Table 3.
[0087]
[table 3]

[0088]
　The magnetic properties of non-oriented electrical steel sheet of each test number in Experimental Example 3, by carrying out the stress relief annealing, if compared with the absence of the stress relief annealing, although enhancing overall, in particular, chemical composition of the steel sheet test No. 27, 28, 31 in the range of the present invention, and 32, were excellent in iron loss and magnetic flux density. Meanwhile, La, Ce, Pr, the total content of Nd, and, Test No. 29 Ca content outside the lower from the scope of the present invention, La, Ce, Pr, Nd, at substantially the same composition except for Ca and the iron loss and magnetic flux density was inferior as compared with the one test No. 27. Also, Test No. 30 Si + 0.5 × Mn falls off low, the iron loss was inferior. As described above, even when performing the stress relief annealing, the non-oriented electrical steel sheet according to the present invention, it became clear that the magnetic characteristics are improved.
[0089]
　Having described in detail preferred embodiments of the present invention with reference to the accompanying drawings, the present invention is not limited to the above examples. It would be appreciated by those skilled in the relevant field of technology of the present invention, within the scope of the technical idea described in the claims, it is intended to cover various changes and modifications , also such modifications are intended to fall within the technical scope of the present invention.
Industrial Applicability
[0090]
　According to the present invention, good cold rollability, and excellent since non-oriented electrical steel sheet having a magnetic property can be obtained, it has high industrial applicability.
DESCRIPTION OF SYMBOLS
[0091]
　10 non-oriented electrical steel sheets
　11 base steel
　13 insulation coating

The scope of the claims
[Requested item 1]
　Chemical composition, in
　mass%, C: 0%, greater than 0.0050% or
　less,
　Si: 3.0% ~ 4.0%, Mn: 1.2% ~
　3.3%, P: 0% greater, less than Pasento
　0.030, S: 0 Pasento than, 0.0050% or
　less, Sol. Al: 0%, greater than 0.0040% or
　less, N: 0%, greater than 0.0040% or
　less, La, Ce, Pr, Nd 1 or more kinds of 0.0005% in total - 0.0200% ,
　Ca:
　0.0005% ~
　0.0100%, Ti: 0.0005% ~ 0.0100%,
　Sn: 0% ~ 0.10%, Sb: 0% ~
　0.10%, Mg: 0% ~ 0.0100%,
contain, the balance being Fe and
　impurities, Si-0.5 × Mn: is 2.0% or
　more, Si + 0.5 × Mn: at 3.8% or more
and wherein the non-oriented electrical steel sheet to be.
[Requested item 2]
　The chemical
　composition,
　Sn: 0.005% ~ 0.10%, Sb: 0.005% ~ 0.10%,
containing one or two substituents selected from
and wherein the claim 1 non-oriented electrical steel sheet.
[Requested item 3]
　The chemical
　composition, Mg: 0.0005% ~ 0.0100%
containing
non-oriented electrical steel sheet according to claim 1 or 2, characterized in that.