JP6973369B2

JP6973369B2 - Directional electromagnetic steel plate and its manufacturing method

Info

Publication number: JP6973369B2
Application number: JP2018245508A
Authority: JP
Inventors: 博貴井上; 誠司岡部; 健大村
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2018-12-27
Filing date: 2018-12-27
Publication date: 2021-11-24
Anticipated expiration: 2038-12-27
Also published as: JP2020105589A

Description

本発明は、変圧器などの鉄心材料に好適な方向性電磁鋼板およびその製造方法に関するものである。 The present invention relates to a grain-oriented electrical steel sheet suitable for an iron core material such as a transformer and a method for manufacturing the same.

鉄の磁化容易軸である＜００１＞方位が鋼板の圧延方向に高度に揃った結晶組織を有する方向性電磁鋼板は、特に電力用変圧器の鉄心材料として用いられている。かかる電力用変圧器は、その鉄心構造から積鉄心変圧器と巻鉄心変圧器に大別される。 A grain-oriented electrical steel sheet having a crystal structure whose <001> orientation, which is an axis for easily magnetizing iron, is highly aligned in the rolling direction of the steel sheet, is particularly used as an iron core material for a power transformer. Such power transformers are roughly classified into stacked iron core transformers and wound iron core transformers according to their iron core structures.

積鉄心変圧器とは、所定の形状に切断した鋼板を積層することによって鉄心を形成するものである。一方、巻鉄心変圧器は、鋼板を巻き重ねて鉄心を形成するものである。変圧器鉄心として要求される特性は種々あるが、特に重要なのは鉄損が小さいことである。 A product core transformer is a transformer that forms an iron core by laminating steel plates cut into a predetermined shape. On the other hand, a wound iron core transformer is one in which steel plates are wound to form an iron core. There are various characteristics required for a transformer core, but the most important one is that the iron loss is small.

その観点から、鉄心素材である方向性電磁鋼板に要求される特性として、鉄損値が小さいことが挙げられ、この特性は重要である。ここで、鉄損を下げるための技術の一つとして、鋼板表面にレーザビーム、プラズマビームまたは電子ビーム等を照射することによって周期的な歪みを導入し、磁区を細分化して鉄損を低減する技術がある。 From this point of view, a characteristic required for grain-oriented electrical steel sheets, which is an iron core material, is that the iron loss value is small, and this characteristic is important. Here, as one of the techniques for reducing iron loss, periodic strain is introduced by irradiating the surface of the steel sheet with a laser beam, plasma beam, electron beam, etc., and the magnetic domain is subdivided to reduce iron loss. There is technology.

例えば、特許文献１には、最終製品板にレーザビームを照射し、鋼板表層に高転位密度領域を導入し、磁区幅を狭くすることで、鋼板の鉄損を低減する技術が提案されている。また、特許文献２には、電子ビーム照射により方向性電磁鋼板の圧延方向と交差する向きに点列に熱歪みを導入するに当たり、照射点間隔や照射エネルギーを適正化することで、鉄損を低減する技術が記載されている。これらの技術は、主磁区を細分化するだけでなく、鋼板内部に還流磁区と呼ばれる新たな磁区構造を形成することで、低鉄損を実現するものである。 For example, Patent Document 1 proposes a technique for reducing iron loss in a steel sheet by irradiating the final product plate with a laser beam, introducing a high dislocation density region into the surface layer of the steel sheet, and narrowing the magnetic domain width. .. Further, in Patent Document 2, when introducing thermal strain into a point array in a direction intersecting the rolling direction of a grain-oriented electrical steel sheet by electron beam irradiation, iron loss is caused by optimizing the irradiation point interval and irradiation energy. Techniques for reduction are described. These techniques not only subdivide the main magnetic domain, but also realize low iron loss by forming a new magnetic domain structure called a reflux magnetic domain inside the steel sheet.

ここで、鋼板の鉄損特性を表す代表的な指標は、周波数50 Hz、最大磁束密度1.7Tにおける鉄損W_17/50の値であり、鋼板はその大きさによりグレード分けされている。また、近年の環境規制の強化によって、変圧器の効率化がより求められる結果、1.7Tよりも低い磁束密度での磁化領域で鋼板が使われるケースも多くなってきている。さらに、近年増えた太陽光発電等に接続された小規模系統で使われる変圧器では、励磁突入電流への対応も必要であり、それには、高い磁化領域における磁束密度、すなわち磁化力800A/mにおける磁束密度B₈といった磁気特性にも優れる必要がある。 _{Here, a typical index showing the iron loss characteristics of the steel sheet is the value of the iron loss W 17/50 at} a frequency of 50 Hz and a maximum magnetic flux density of 1.7 T, and the steel sheets are graded according to their size. In addition, as a result of the recent tightening of environmental regulations, the efficiency of transformers is required to be improved, and as a result, steel plates are often used in the magnetization region with a magnetic flux density lower than 1.7T. Furthermore, in transformers used in small-scale systems connected to solar power generation, which has increased in recent years, it is also necessary to cope with the excitation inrush current, which is the magnetic flux density in the high magnetization region, that is, the magnetization force of 800 A / m. It is also necessary to have excellent magnetic characteristics such as the magnetic flux density B _{8 in.}

特公昭５７−２２５２号公報Special Publication No. 57-2252 特開２０１２−０３６４５０号公報Japanese Unexamined Patent Publication No. 2012-036450

前述したように、最近では、最大磁束密度1.7Tといった鋼板グレードを決める磁化領域での鉄損W_17/50が小さいだけでなく、1.0〜1.5Tといった低い磁束密度となるように低い磁化力で磁化した領域（以下、単に低い磁化領域という）での鉄損に優れ、かつ磁化力800A/mといった高い磁化力で磁化した領域（以下、単に高い磁化領域という）における磁束密度B₈といった磁気特性にも優れる方向性電磁鋼板が求められている。 _{As mentioned above, recently, not only is the iron loss W 17/50} in the magnetization region that determines the steel plate grade, such as the maximum magnetic flux density of 1.7 T, small, but also with a low magnetization force so that the magnetic flux density is as low as 1.0 to 1.5 T. Excellent iron loss in the magnetized region (hereinafter simply referred to as low magnetization region), and magnetic characteristics such as magnetic _{flux density B 8} in the region magnetized with a high magnetization force of 800 A / m (hereinafter simply referred to as high magnetization region). There is also a demand for an excellent directional electromagnetic steel plate.

低い磁化領域での磁気特性を向上させるためには、1.0〜1.5Tにおける鉄損を小さくすればよい。ここで、かかる領域での鉄損を小さくするためには、ビーム照射により導入される歪み量を増やし、磁区細分化効果を強くすれば良い。しかし、導入する歪み量を増やすと、B₈といった高い磁化領域における磁束密度が劣化するという問題があった。 In order to improve the magnetic properties in the low magnetization region, the iron loss at 1.0 to 1.5T may be reduced. Here, in order to reduce the iron loss in such a region, the amount of strain introduced by beam irradiation may be increased to strengthen the magnetic domain subdivision effect. However, when the amount of strain to be introduced is increased, there is a problem that the magnetic flux density in a high magnetization region such as _{B 8 deteriorates.}

本発明は、上記の問題を克服し、低い磁化領域から高い磁化領域までの磁気特性に優れた方向性電磁鋼板を提供することを目的とする。また、本発明は、かかる磁気特性に優れた方向性電磁鋼板の製造方法を併せて提供することを目的とする。 An object of the present invention is to overcome the above-mentioned problems and to provide a grain-oriented electrical steel sheet having excellent magnetic properties from a low magnetization region to a high magnetization region. Another object of the present invention is to provide a method for manufacturing a grain-oriented electrical steel sheet having excellent magnetic properties.

鉄損や磁束密度といった磁気特性に影響を与えるのは、磁区細分化処理をする際に、ビーム照射等により与えられる歪み体積の大小やその分布であることが知られている。 It is known that what affects the magnetic characteristics such as iron loss and magnetic flux density is the magnitude and distribution of the strain volume given by beam irradiation or the like during the magnetic domain subdivision process.

ここで、鋼板単位面積当たりに導入される歪み体積を増やすこと、すなわち、線状歪みの列間隔を狭めたりすることや、ビーム出力を上げる等でそれぞれの線状歪みの体積を増やしたりすることで、主磁区はより細分化される。
そして、主磁区が細分化された場合、低い磁化領域では、主磁区の180°磁壁移動により磁化が進行するので、主磁区の磁区幅が狭い程、磁壁の移動距離は小さくなり、磁壁の移動速度が小さくなる。その結果、渦電流損が減少し、鉄損は減少する。しかしながら、高い磁化領域では、主磁区の180°磁壁移動だけでは磁化が進行できなくなる。そのため、磁化回転は生じるものの、増えた歪みが磁化回転を阻害する。その結果、高い磁化領域での鉄損や磁束密度といった磁気特性は劣化してしまう。 Here, increasing the strain volume introduced per unit area of the steel sheet, that is, narrowing the column spacing of the linear strain, increasing the beam output, etc., to increase the volume of each linear strain. So, the main magnetic domain is further subdivided.
When the main magnetic domain is subdivided, in the low magnetization region, the magnetization progresses due to the 180 ° domain wall movement of the main magnetic domain. Therefore, the narrower the magnetic domain width of the main magnetic domain, the smaller the domain wall movement distance and the movement of the domain wall. The speed decreases. As a result, the eddy current loss is reduced and the iron loss is reduced. However, in the high magnetization region, magnetization cannot proceed only by the 180 ° domain wall movement of the main magnetic domain. Therefore, although the magnetization rotation occurs, the increased strain hinders the magnetization rotation. As a result, magnetic properties such as iron loss and magnetic flux density in a high magnetization region deteriorate.

すなわち、単純に歪み体積やその分布を制御するだけでは、低い磁化領域から高い磁化領域までの磁気特性に優れた鋼板を作製することはできない。そこで、発明者らは、ビーム照射により与えられる歪み導入体積やその分布だけではなく、その歪み導入体積の分布の変化に着目して、磁区細分化を制御することを試みた。 That is, it is not possible to produce a steel sheet having excellent magnetic properties from a low magnetization region to a high magnetization region by simply controlling the strain volume and its distribution. Therefore, the inventors attempted to control the subdivision of the magnetic domain by paying attention not only to the change in the strain introduction volume and its distribution given by beam irradiation but also to the change in the distribution of the strain introduction volume.

従来の磁区細分化処理を行った鋼板は、図１に示すとおり、一定の歪み体積を持つ線状歪み領域が周期的な間隔で並んでいる。そこで、低い磁化領域と高い磁化領域での磁気特性の両立を検討するため、発明者らは、図２に示すように、線状歪み領域中の歪みの体積が各線状歪みごとに異なるように制御することを試みた。 As shown in FIG. 1, in the conventional steel sheet subjected to the magnetic domain subdivision treatment, linear strain regions having a constant strain volume are arranged at periodic intervals. Therefore, in order to examine both the low magnetization region and the high magnetization region, the inventors set the strain volume in the linear strain region to be different for each linear strain, as shown in FIG. I tried to control it.

その結果、発明者らは、以下の条件を満たすように線状歪み領域を導入すると、低い磁化領域と高い磁化領域での磁気特性が両立できることを知見した。
(1)導入された線状歪み領域は圧延方向断面積が異なる２種以上存在すること
(2)(1)の圧延方向断面積が最大のものと最小のものとで20％以上90％以下の範囲で異なること
好ましくは、
(3)(2)の圧延方向断面積の異なる線状歪み領域が圧延方向に交互に並ぶこと
である。 As a result, the inventors have found that when the linear strain region is introduced so as to satisfy the following conditions, the magnetic properties in the low magnetization region and the high magnetization region can be compatible with each other.
(1) There are two or more types of introduced linear strain regions with different rolling direction cross-sectional areas.
(2) It is preferable that the cross-sectional area in the rolling direction of (1) differs between the maximum one and the minimum one in the range of 20% or more and 90% or less.
(3) The linear strain regions having different cross-sectional areas in the rolling direction of (2) are alternately arranged in the rolling direction.

次に、本発明を導くに至った実験結果について説明する。
＜実験１＞
方向性電磁鋼板（0.23mm厚、ビーム照射前のB₈：1.935T）に、電子ビーム照射装置を用いて、表１に示す照射間隔（列間隔）、加速電圧、ビーム電流、ビーム径および走査速度の各条件で、磁区細分化処理を施した。その際に、図３に示すように交互に並ぶ領域Iおよび領域IIの線状歪み領域で照射条件を変えて、導入する歪み体積を異なるようにした場合と、同一の照射条件とした場合の鋼板とを作製し、磁気特性をそれぞれ測定して比較した。その際の磁気特性評価は、鋼板を幅500mm×長さ500mmに剪断し、JIS C 2556に規定されている単板磁気特性試験によって行った。なお、低い磁化領域での磁気特性としてW_13/50、高い磁化領域での磁気特性としてB₈、さらに鋼板グレードを決める特性であるW_17/50をそれぞれ評価した。図４に電子ビームの照射条件毎の鋼板のW_13/50の値、図５に電子ビームの照射条件毎の鋼板のB₈の値、図６に電子ビームの照射条件毎の鋼板のW_17/50の値をそれぞれ示す。 Next, the experimental results that led to the present invention will be described.
<Experiment 1>
Irradiation interval (row interval), acceleration voltage, beam current, beam diameter and scanning shown in Table 1 are used on a directional electromagnetic steel plate ( _{0.23 mm thickness, B 8: 1.935 T before beam irradiation) using an electron beam irradiation device.} Magnetic domain subdivision processing was performed under each condition of speed. At that time, as shown in FIG. 3, the irradiation conditions are changed in the linear strain regions of the regions I and II that are alternately arranged so that the strain volume to be introduced is different, and the irradiation conditions are the same. Steel plates were prepared, and their magnetic properties were measured and compared. At that time, the magnetic characteristics were evaluated by shearing the steel plate to a width of 500 mm and a length of 500 mm and performing a single plate magnetic characteristics test specified in JIS C 2556. Incidentally, it was evaluated low W _13/50 as the magnetic properties of the magnetization region, B ₈ as the magnetic properties at high magnetization region, the W _17/50 is a characteristic that further define the steel grade, respectively. _{Fig. 4 shows the value of W 13/50} of the steel sheet for each electron beam irradiation condition, Fig. 5 shows the value of B ₈ of the steel sheet for each electron beam irradiation condition, and Fig. 6 shows the value of the steel sheet for each electron beam irradiation condition W _{17 The values of / 50} are shown respectively.

ビーム電流が大きい(歪み導入量が多い)照射条件のみで歪を導入した条件1,4,7では、低い磁化領域での磁気特性W_13/50や、鋼板グレードを決める特性W_17/50はいずれも良好なものの、高い磁化領域での磁気特性B₈値は劣った。逆に、ビーム電流が小さい(歪み導入量が少ない)照射条件のみで歪を導入した条件3,6,9では、高い磁化領域での磁気特性B₈は良好なものの、低い磁化領域での磁気特性W_13/50、鋼板グレードを決める特性W_17/50は劣った。一方、ビーム電流が大きい(歪み導入量が多い)照射条件で歪を導入した領域（領域I）とビーム電流が小さい(歪み導入量が少ない)照射条件で歪を導入した領域（領域II）とが導入された条件2,5,8は、低い磁化領域での磁気特性W_13/50、鋼板グレードを決める特性W_17/50、高い磁化領域での磁気特性B₈について、いずれも良好な結果になった。 In condition 1,4,7 introduced strain only by the beam current is large (distortion introduced amount is large) irradiation conditions, the magnetic characteristics W _13/50 and at a low magnetization region, characteristic W _17/50 determining the steel grade All were good, but the magnetic property B ₈ value in the high magnetization region was inferior. On the contrary, under the conditions 3, 6 and 9 where the strain is introduced only under the irradiation condition where the beam current is small (the amount of strain introduced is small), the magnetic property B ₈ in the high magnetization region is good, but the magnetism in the low magnetization region is good. characteristics W _13/50, characteristics W _17/50 to determine the steel grade is inferior. On the other hand, the region where the strain is introduced under the irradiation condition where the beam current is large (the amount of strain introduced is large) (region I) and the region where the strain is introduced under the irradiation condition where the beam current is small (the amount of strain introduced is small) (region II). results There conditions 2,5,8 introduced, the magnetic characteristics of a low magnetization region W _13/50, characteristics W _17/50 decide steel grade, the magnetic properties B ₈ at high magnetization region, both good Became.

上記実験結果より、異なる歪み体積を有する線状歪み領域を並べることで、低い磁化領域と高い磁化領域での磁気特性が両立することが可能であることが示唆された。そこで、発明者らは、異なる歪み体積を有する線状歪み領域を如何に並べれば良いのか検討を行った。 From the above experimental results, it was suggested that by arranging the linear strain regions having different strain volumes, it is possible to achieve both the magnetic characteristics in the low magnetization region and the magnetic characteristics in the high magnetization region. Therefore, the inventors examined how to arrange linear strain regions having different strain volumes.

まず、各線状歪み領域が有する歪み体積を定量化することを試みた。その結果、指標として、以下に定義される線状歪み領域の圧延方向断面積を用いることが好ましいことを見出した。
［線状歪み領域の圧延方向断面積］＝［歪み領域の圧延方向幅］×［歪み領域の板厚方向深さ］ First, we tried to quantify the strain volume of each linear strain region. As a result, it was found that it is preferable to use the rolling direction cross-sectional area of the linear strain region defined below as an index.
[Rolling direction cross-sectional area of linear strain region] = [Rolling direction width of strain region] x [Depth in plate thickness direction of strain region]

上記式中の歪み領域の圧延方向幅は、歪み領域に形成する還流磁区の圧延方向幅とする。すなわち、本発明では、磁性コロイドを利用して磁区パターンの可視化が可能なマグネットビュアーによって歪み領域に形成する還流磁区を観察し、その幅を計測して歪み領域の圧延方向幅とする。 The rolling direction width of the strained region in the above equation is the rolling direction width of the reflux magnetic domain formed in the strained region. That is, in the present invention, a recirculated magnetic domain formed in a strained region is observed by a magnet viewer capable of visualizing a magnetic domain pattern using a magnetic colloid, and the width thereof is measured to obtain the rolling direction width of the strained region.

また、上記式中の歪み領域の板厚方向深さは、以下の方法によって測定される塑性歪み深さとする。この方法は、歪み領域を有する鋼板を、化学研磨や電解研磨等で減厚すると、塑性歪み領域の最深部まで削れた段階で、歪み領域の還流磁区が消失することを利用する。すなわち、まず、鋼板を少しずつ減厚して、還流磁区が存在するかをマグネットビュアーで観察する。ついで、減厚量(研磨量)を徐々に増やしていき、還流磁区が観察できなくなった時点での研磨深さを塑性歪み深さとする。なお、本発明では、歪み領域の断面積が矩形でない場合も矩形と見做す。図７は、本発明に従う歪み領域の板厚方向深さの定義の概念図を示している。 Further, the depth of the strain region in the above equation in the plate thickness direction is the plastic strain depth measured by the following method. This method utilizes the fact that when a steel sheet having a strained region is thinned by chemical polishing, electrolytic polishing, or the like, the reflux magnetic domain in the strained region disappears at the stage where the deepest part of the plastic strained region is scraped. That is, first, the thickness of the steel sheet is gradually reduced, and the presence of the reflux magnetic domain is observed with a magnet viewer. Then, the thickness reduction amount (polishing amount) is gradually increased, and the polishing depth at the time when the reflux magnetic domain cannot be observed is defined as the plastic strain depth. In the present invention, even if the cross-sectional area of the strained region is not rectangular, it is regarded as rectangular. FIG. 7 shows a conceptual diagram of the definition of the depth in the plate thickness direction of the strain region according to the present invention.

＜実験２＞
方向性電磁鋼板（0.23mm厚、磁区細分化処理前B₈：1.935T）に、電子ビーム照射装置を用いて磁区細分化処理を行い、表２−１に示す照射条件で磁区細分化し、様々に異なる歪み体積の組み合わせの線状歪み領域を交互に並べた鋼板を作製した。各線状歪み領域が有する歪み体積として、上記した線状歪み領域の圧延方向断面積を指標とした。実験１と同様に、500ｍｍ角の試料にて単板磁気測定を行い、低い磁化領域での磁気特性W_13/50、鋼板グレードを決める特性W_17/50、高い磁化領域での磁気特性B₈をそれぞれ評価した。 <Experiment 2>
A directional electromagnetic steel sheet (0.23 mm thick, before magnetic domain subdivision treatment B ₈ : 1.935T) was subjected to magnetic domain subdivision processing using an electron beam irradiation device, and was subdivided into magnetic domains under the irradiation conditions shown in Table 2-1. A steel plate in which linear strain regions of combinations of different strain volumes were alternately arranged was produced. As the strain volume of each linear strain region, the cross-sectional area in the rolling direction of the linear strain region described above was used as an index. As in Experiment 1, performs a single plate magnetic measurements in a sample of 500mm square, the magnetic characteristics of a low magnetization region W _13/50, characteristics W _17/50 decide steel grade, magnetic properties B ₈ at high magnetization region We evaluated each.

表２−２に、磁気特性の測定結果を記載する。低い磁化領域と高い磁化領域での磁気特性が両立しているかの判定を、以下の条件で整理した。
"◎"：W_13/50≦0.38W/kgかつB₈≧1.930TかつW_17/50≦0.70 W/kg
"○"：◎の判定を満たさないかつW_13/50≦0.40W/kgかつB₈≧1.925TかつW_17/50≦0.72W/kg
"×1"：W_13/50＞0.40W/kg
"×2"：B₈＜1.925T Table 2-2 shows the measurement results of the magnetic characteristics. Judgment as to whether the magnetic characteristics in the low magnetization region and the high magnetization region are compatible is summarized under the following conditions.
_{"◎": W 13/50 ≦ 0.38W} / kg and B ₈ ≧ 1.930T and W _17/50 ≦ 0.70 W / kg
"○": ◎ Not satisfy the judgment and W _13/50 ≦ 0.40W / kg and B ₈ ≧ 1.925T and W _17/50 ≦ 0.72W / kg
_{"× 1": W 13/50>} 0.40W / kg
"× 2": B ₈ <1.925T

上記の判定のうち、◎または○の判定を得られた条件は、低い磁化領域と高い磁化領域での磁気特性が両立しており、優れた条件である。×1の判定となった条件は、歪み導入体積が少なく、十分な磁区細分化効果が得られていない。一方、×2の判定となった条件は、歪み導入体積が多く、高い磁化領域での磁気特性に劣っている。 Of the above judgments, the condition in which the judgment of ⊚ or ◯ is obtained is an excellent condition because the magnetic characteristics in the low magnetization region and the high magnetization region are compatible. The condition for determining × 1 is that the strain introduction volume is small and a sufficient magnetic domain subdivision effect is not obtained. On the other hand, the condition of determining × 2 is that the strain introduction volume is large and the magnetic characteristics in the high magnetization region are inferior.

上記実験中、◎、○の判定を得られた条件では、領域IとIIの歪み領域の圧延方向断面積が20％以上90％以下の範囲で異なっており、さらに◎の判定を得られた条件は、領域IとIIの歪み領域の圧延方向断面積が30％以上80％以下の範囲で異なっていた。 During the above experiment, under the conditions where the judgments of ◎ and ○ were obtained, the cross-sectional areas in the rolling direction of the strained areas of regions I and II differed in the range of 20% or more and 90% or less, and further, the judgment of ◎ was obtained. The conditions differed in the range where the rolling direction cross-sectional area of the strained regions of regions I and II was 30% or more and 80% or less.

以上の実験から、鋼板の片面に導入された線状歪み領域の圧延方向断面積が少なくとも２種あり、かつかかる圧延方向断面積が20％以上90％以下異なっている線状歪み領域が圧延方向に並ぶ方向性電磁鋼板であることが、低い磁化領域と高い磁化領域での磁気特性が両立できる方向性電磁鋼板であることが明らかになり、本発明の完成にいたった。 From the above experiments, there are at least two types of rolling direction cross-sectional areas of the linear strain region introduced on one side of the steel plate, and the linear strain regions in which the rolling direction cross-sectional areas differ by 20% or more and 90% or less are the rolling directions. It has been clarified that the directional electromagnetic steel sheets that are lined up in the same direction are directional electromagnetic steel sheets that can achieve both magnetic properties in a low magnetization region and a high magnetization region, and the present invention has been completed.

前述のように、異なる圧延方向断面積を有する線状歪み領域を圧延方向に並べることで、低い磁化領域と高い磁化領域での磁気特性が両立できる理由については必ずしも明確に言えないが、発明者らは以下のように推定している。
すなわち、線状歪み領域においては、その導入歪によって、歪み線と平行方向（圧延方向を横切る方向）に強い圧縮応力が働くため、その結果として歪み領域同士の間には引張応力が働くこととなる。しかしながら、隣りあう歪み領域同士の歪み導入量が異なる場合は、それぞれの歪み領域に働く圧縮応力が不均衡となる。その結果、歪み領域同士の間には、かかる不均衡により生じる応力も加味されてより強い引張応力が発生すると考えられる。 As described above, it is not always clear why the magnetic properties in the low magnetization region and the high magnetization region can be achieved by arranging the linear strain regions having different rolling direction cross-sectional areas in the rolling direction, but the inventor Et al. Estimate as follows.
That is, in the linear strain region, strong compressive stress acts in the direction parallel to the strain line (direction crossing the rolling direction) due to the introduced strain, and as a result, tensile stress acts between the strain regions. Become. However, when the amount of strain introduced between adjacent strain regions is different, the compressive stress acting on each strain region becomes imbalanced. As a result, it is considered that stronger tensile stress is generated between the strained regions in consideration of the stress caused by such imbalance.

ここで、高い磁化領域での磁気特性を歪み導入により劣化させないためには、磁区細分化効果を十分得られる範囲で、なるべく歪み導入量を減らす必要があるが、上述したように、歪み領域同士の間により強い引張応力が働けば、より強い磁気弾性効果により磁区細分化効果が大きくなって、少ない歪み導入量でも十分な磁区細分化効果が得られる。よって、本発明では、異なる歪み体積を有する線状歪み領域を圧延方向に並べることで、歪み領域同士の間に働く引張応力を高め、少ない歪み導入量かつ強い磁区細分化効果の両立を図ることができると考えている。 Here, in order not to deteriorate the magnetic characteristics in the high magnetization region by strain introduction, it is necessary to reduce the strain introduction amount as much as possible within the range where the magnetic domain subdivision effect can be sufficiently obtained. If a stronger tensile stress acts between them, the magnetic domain subdivision effect becomes larger due to the stronger magnetic elastic effect, and a sufficient magnetic domain subdivision effect can be obtained even with a small amount of strain introduced. Therefore, in the present invention, by arranging linear strain regions having different strain volumes in the rolling direction, the tensile stress acting between the strain regions is increased, and both a small amount of strain introduction and a strong magnetic domain subdivision effect are achieved. I think I can do it.

本発明は上記の知見に基づき得られたものであり、本発明の要旨構成は次のとおりである。
１．鋼板片面に、圧延方向を横切る向きに線状に延びかつ圧延方向に間隔を置いて並ぶ、複数本の線状歪み領域を有する方向性電磁鋼板であって、
上記線状歪み領域は、圧延方向断面積の異なる少なくとも２種を有し、上記線状歪み領域において、最も大きい圧延方向断面積をＡ（mm²）および最も小さい圧延方向断面積をＢ（mm²）とするとき、｛（Ａ−Ｂ）／Ａ｝×１００が20％以上90％以下である方向性電磁鋼板。 The present invention has been obtained based on the above findings, and the gist structure of the present invention is as follows.
1. 1. A grain-oriented electrical steel sheet having a plurality of linear strain regions extending linearly in a direction crossing the rolling direction and arranging at intervals in the rolling direction on one side of the steel sheet.
The linear strain region has at least two types having different rolling direction cross-sectional areas, and in the linear strain region, the largest rolling direction cross-sectional area is A (mm ² ) and the smallest rolling direction cross-sectional area is B (mm). ² ), a directional electromagnetic steel plate in which {(AB) / A} × 100 is 20% or more and 90% or less.

２．前記面積Ａを有する線状歪み領域および前記面積Ｂを有する線状歪み領域を圧延方向に交互に繰り返して備える前記１に記載の方向性電磁鋼板。 2. 2. The grain-oriented electrical steel sheet according to 1 above, wherein the linear strain region having the area A and the linear strain region having the area B are alternately and repeatedly provided in the rolling direction.

３．前記１または２に記載の方向性電磁鋼板を製造する方法であって、レーザビーム照射あるいは電子ビーム照射により、鋼板片面に、圧延方向を横切る向きに線状に延びかつ圧延方向に間隔を置いて並ぶ、複数本の線状歪み領域を導入するに際し、上記線状歪み領域として圧延方向断面積の異なる少なくとも２種を導入し、かつ上記線状歪み領域において、最も大きい圧延方向断面積をＡ（mm²）および最も小さい圧延方向断面積をＢ（mm²）とするとき、｛（Ａ−Ｂ）／Ａ｝×１００が20％以上90％以下の範囲となる、上記レーザビーム照射あるいは電子ビーム照射の照射を行う方向性電磁鋼板の製造方法。 3. 3. The method for manufacturing a directional electromagnetic steel plate according to 1 or 2 above, wherein the directional electromagnetic steel plate is linearly extended on one side of the steel plate in a direction crossing the rolling direction and spaced in the rolling direction by laser beam irradiation or electron beam irradiation. When introducing a plurality of linear strain regions that are lined up, at least two types having different rolling direction cross-sectional areas are introduced as the linear strain regions, and the largest rolling direction cross-sectional area is A (in the linear strain regions). When mm ² ) and the smallest rolling direction cross-sectional area are B (mm ² ), {(AB) / A} × 100 is in the range of 20% or more and 90% or less. A method for manufacturing a directional electromagnetic steel plate to be irradiated.

４．前記面積Ａを有する線状歪み領域および前記面積Ｂを有する線状歪み領域を圧延方向に交互に繰り返して鋼板片面に備えるよう前記レーザビーム照射あるいは電子ビーム照射の条件を制御する前記３に記載の方向性電磁鋼板の製造方法。 4. 3. The above 3 is described in which the conditions of laser beam irradiation or electron beam irradiation are controlled so that the linear strain region having the area A and the linear strain region having the area B are alternately repeated in the rolling direction on one side of the steel sheet. Manufacturing method of directional electromagnetic steel sheet.

本発明によれば、低い磁化領域から高い磁化領域までの広範囲において、磁気特性に優れた方向性電磁鋼板を提供することができる。また、併せて、その方向性電磁鋼板を効果的に得られる製造方法を提供することができる。 According to the present invention, it is possible to provide a grain-oriented electrical steel sheet having excellent magnetic properties in a wide range from a low magnetization region to a high magnetization region. In addition, it is possible to provide a manufacturing method for effectively obtaining the grain-oriented electrical steel sheet.

従来の磁区細分化処理を行った鋼板の線状歪み領域を示す図である。It is a figure which shows the linear strain region of the steel sheet which performed the conventional magnetic domain subdivision processing. 本発明で検討した磁区細分化処理を行った鋼板の線状歪み領域を示す図である。It is a figure which shows the linear strain region of the steel sheet which performed the magnetic domain subdivision processing examined in this invention. 交互に並ぶ領域Iおよび領域IIの線状歪み領域で照射条件を変えて、導入する歪み体積を異なるように磁区細分化処理を行った鋼板の線状歪み領域を示す図である。It is a figure which shows the linear strain region of the steel sheet which performed the magnetic domain subdivision treatment so that the irradiation condition is changed in the linear strain region of the region I and the region II which are arranged alternately, and the strain volume to be introduced is different. 電子ビームの照射条件毎の鋼板のW_13/50の値を示した図である。It is the figure which showed the value _{of W 13/50} of a steel plate for each irradiation condition of an electron beam. 電子ビームの照射条件毎の鋼板のB₈の値を示した図である。It is the figure which showed the value _{of B 8} of the steel plate for each irradiation condition of an electron beam. 電子ビームの照射条件毎の鋼板のW_17/50の値を示した図である。It is the figure which showed the value _{of W 17/50} of a steel plate for each irradiation condition of an electron beam. 本発明に従う歪み領域の板厚方向深さの定義の概念図である。It is a conceptual diagram of the definition of the depth in the plate thickness direction of the strain region according to the present invention.

以下、本発明の詳細を説明する。
前述の通り、低い磁化領域から高い磁化領域までの磁気特性に優れた方向性電磁鋼板には、以下の条件で、鋼板片面に、圧延方向を横切る向きに線状に延びかつ圧延方向に間隔を置いて並ぶ、複数本の線状歪み領域を有することが重要である。
(1)導入された線状歪み領域は圧延方向断面積が異なる２種以上存在すること
(2)(1)の圧延方向断面積が最大のものと最小のものとで20％以上90％以下の範囲で異なること
好ましくは、
(3)(2)の圧延方向断面積の異なる線状歪み領域が圧延方向に交互に並ぶこと
より好ましくは、
(4)上記圧延方向断面積の異なる範囲が30％以上80％以下であること
(5)上記線状歪み領域は、圧延方向に対して６０〜１２０°の角度で周期的に線状に延びること
である。 Hereinafter, the details of the present invention will be described.
As described above, for grain-oriented electrical steel sheets with excellent magnetic properties from the low magnetization region to the high magnetization region, they extend linearly on one side of the steel sheet in the direction crossing the rolling direction and are spaced in the rolling direction under the following conditions. It is important to have multiple linear strain areas that are lined up side by side.
(1) There are two or more types of introduced linear strain regions with different cross-sectional areas in the rolling direction.
(2) It is preferable that the cross-sectional area in the rolling direction of (1) differs between the maximum one and the minimum one in the range of 20% or more and 90% or less.
(3) It is more preferable that linear strain regions having different cross-sectional areas in the rolling direction of (2) are alternately arranged in the rolling direction.
(4) The range of different cross-sectional areas in the rolling direction is 30% or more and 80% or less.
(5) The linear strain region periodically extends linearly at an angle of 60 to 120 ° with respect to the rolling direction.

本発明に従う線状歪み領域を有する方向性電磁鋼板で、上記線状歪み領域の圧延方向断面積を少なくとも２種（例えば領域IとII）とし、該圧延方向断面積の大きい領域IをＡ（mm²）、小さい領域IIをＢ（mm²）とするとき、ＡとＢの比率（％）が20％以上90％以下（＝｛（Ａ−Ｂ）／Ａ｝×１００）（本発明において断面積差ともいう）とする。好ましくは、面積Ａを有する線状歪み領域と面積Ｂを有する線状歪み領域とを圧延方向に交互に繰り返す。また、上記圧延方向断面積の異なる、すなわち断面積差を有する歪み領域は２，３種が好ましい。
なお、本発明において、ＡとＢの比率（％）は20％以上90％以下の範囲とするが、低い磁化領域と高い磁化領域での磁気特性が効果的に両立できるからである。好ましくは、上記比率で30％以上80％以下である。 In a directional electromagnetic steel plate having a linear strain region according to the present invention, the rolling direction cross-sectional area of the linear strain region is at least two types (for example, regions I and II), and the region I having a large rolling direction cross-sectional area is A (for example, region I and II). mm ² ), where B (mm ² ) is the small area II, the ratio (%) of A and B is 20% or more and 90% or less (= {(AB) / A} × 100) (in the present invention). (Also called cross-sectional area difference). Preferably, the linear strain region having the area A and the linear strain region having the area B are alternately repeated in the rolling direction. Further, it is preferable that there are two or three types of strain regions having different cross-sectional areas in the rolling direction, that is, differences in cross-sectional area.
In the present invention, the ratio (%) of A and B is in the range of 20% or more and 90% or less, because the magnetic properties in the low magnetization region and the high magnetization region can be effectively compatible. Preferably, the above ratio is 30% or more and 80% or less.

本発明において、線状の歪みの圧延方向断面積は、前述したように、以下の通りに定義し測定する。
［線状歪み領域の圧延方向断面積］＝［歪み領域の圧延方向幅］×［歪み領域の板厚方向深さ］
［歪み領域の圧延方向幅］は、歪み領域に形成する還流磁区の圧延方向幅で定義する。磁性コロイドを利用して磁区パターンの可視化が可能なマグネットビュアーにより歪み領域に形成する還流磁区を観察し、その幅を計測し、歪み領域の圧延方向幅とする。
なお、上記歪み領域の圧延方向幅は、板幅方向全幅のうち５か所の頻度でサンプリングすれば、本発明の［歪み領域の圧延方向幅］の値として用いることができる。 In the present invention, the rolling direction cross-sectional area of linear strain is defined and measured as follows, as described above.
[Rolling direction cross-sectional area of linear strain region] = [Rolling direction width of strain region] x [Depth in plate thickness direction of strain region]
[Rolling direction width of strain region] is defined by the rolling direction width of the reflux magnetic domain formed in the strain region. Observe the reflux magnetic domain formed in the strained region with a magnet viewer capable of visualizing the magnetic domain pattern using magnetic colloid, measure the width, and use it as the rolling direction width of the strained region.
The rolling direction width of the strain region can be used as the value of the [rolling direction width of the strain region] of the present invention by sampling at a frequency of 5 points out of the total width in the plate width direction.

［歪み領域の板厚方向深さ］は、前述したように、以下の方法によって測定される塑性歪み深さで定義される。歪み領域を有する鋼板を化学研磨や電解研磨等で減厚していくと、塑性歪み領域の最深部まで削れた段階で、歪み領域の還流磁区は消失する。そこで、本発明では、鋼板を少しずつ減厚し、還流磁区が存在するかをマグネットビュアーで観察しながら減厚量(研磨量)を増やしていき、還流磁区が観察できなくなった時点での研磨深さを塑性歪み深さとする。
なお、上記歪み領域の圧延方向深さは、板幅方向全幅のうち５か所の頻度でサンプリングすれば、本発明の［歪み領域の圧延方向深さ］の値として用いることができる。 [Depth in the plate thickness direction of the strain region] is defined by the plastic strain depth measured by the following method, as described above. When a steel sheet having a strained region is thinned by chemical polishing, electrolytic polishing, or the like, the reflux magnetic domain in the strained region disappears at the stage where the deepest part of the plastic strained region is scraped. Therefore, in the present invention, the steel plate is gradually reduced in thickness, and the thickness reduction amount (polishing amount) is increased while observing the existence of the reflux magnetic domain with a magnet viewer, and polishing is performed when the reflux magnetic domain cannot be observed. Let the depth be the plastic strain depth.
The depth of the strained region in the rolling direction can be used as the value of [depth of the strained region in the rolling direction] of the present invention by sampling at a frequency of 5 points out of the total width in the plate width direction.

ここで、本発明の周期的とは、圧延方向に所定の間隔で圧延方向に対して６０〜１２０°の角度で線状に延びることや、鋼板の９５％以上の面積で本発明の条件を満足している場合も含むものとする。いずれの場合も、本発明の効果が得られるからである。 Here, the term "periodic" of the present invention means that the periodicity extends linearly at an angle of 60 to 120 ° with respect to the rolling direction at predetermined intervals in the rolling direction, and the conditions of the present invention are applied to an area of 95% or more of the steel sheet. It also includes cases where you are satisfied. This is because the effect of the present invention can be obtained in either case.

［［歪み導入方法］］
本発明に用いる高エネルギービーム照射装置としては、レーザビームまたは電子ビーム照射装置が挙げられる。これらの装置は、既に幅広く普及しており、一般的な照射装置をいずれも好適に使用することができる。レーザの光源としては、連続波レーザ、パルスレーザのいずれでもよく、ＹＡＧレーザやＣＯ_２レーザ等は問題なく使用することができる。特に、電子ビームは、物質を透過する能力が高いので、板厚方向への歪み導入量を大きく変化させることが可能である。そのため、本発明のように歪み分布を制御する場合には、歪み分布の範囲を制御しやすいため好ましい。 [[Distortion introduction method]]
Examples of the high energy beam irradiating device used in the present invention include a laser beam or electron beam irradiating device. These devices are already widely used, and any general irradiation device can be preferably used. As the light source of the laser, either a continuous wave laser or a pulse laser _{may be used, and a YAG laser, a CO 2} laser, or the like can be used without any problem. In particular, since the electron beam has a high ability to pass through a substance, it is possible to greatly change the amount of strain introduced in the plate thickness direction. Therefore, when controlling the strain distribution as in the present invention, it is preferable because it is easy to control the range of the strain distribution.

［［装置の台数］］
さまざまな要因によって高エネルギービームの走査速度や高エネルギービームの走査幅が制約され、１台の装置ではコイル全面に磁区細分化処理を施すことが困難な場合が多々ある。この場合、板幅方向に複数台の照射装置を用いてコイル全面に高エネルギービームの照射が施される。また本発明では、複数の歪み体積を有する線状歪みを導入するため、複数台の高エネルギービーム照射装置を、コイル進行方向に並べて、高エネルギービーム照射装置毎に条件を変えることが好ましい。 [[Number of devices]]
The scanning speed of the high-energy beam and the scanning width of the high-energy beam are restricted by various factors, and it is often difficult to perform magnetic domain subdivision processing on the entire surface of the coil with one device. In this case, the entire surface of the coil is irradiated with a high energy beam by using a plurality of irradiation devices in the plate width direction. Further, in the present invention, in order to introduce linear strain having a plurality of strain volumes, it is preferable to arrange a plurality of high energy beam irradiation devices in the coil traveling direction and change the conditions for each high energy beam irradiation device.

［［電子ビーム照射条件］］
電子ビーム（以下単にビームともいう）を照射する場合は、その条件、すなわち、加速電圧Ｅ（Ｖ）、ビーム電流Ｉ（Ａ）、走査速度Ｖ（m/s）およびビーム径ｄ(mm)等に特に制限はなく、本発明のパラメータを充足するように組み合わせればよい。歪み領域の圧延方向幅はビーム径の大きさ、歪領域の板厚方向深さは主にビームを走査する単位長さ当たりのエネルギー入熱量（Ｅ×Ｉ/Ｖ）で制御することができる。また、磁区細分化効果を十分に得るために、エネルギー入熱量（Ｅ×Ｉ/Ｖ）は２W・s/mより大きいことが好ましい。また、電子ビーム照射時の真空度は２Pa以下であることが望ましい。これより真空度が悪い（２Pa超の）場合、電子銃から鋼板までの間に存在する残存ガスによって、電子ビーム品質が劣化し、鋼板に導入されるエネルギーが小さくなり、期待通りの磁区細分化効果が得られなくなるためである。
なお、電子ビームの照射は鋼板に連続状に照射しても、点列状に照射しても良い。点列に歪みを導入する方法は、ビームを素早く走査しながら所定の時間間隔で停止し、本発明の要件に適合する時間、その点でビームを照射しつづけた後、また走査を開始するというプロセスを繰り返すというものが挙げられる。電子ビーム照射でこのプロセスを実現するには、容量の大きなアンプを用いて、電子ビームの偏向電圧を変化させれば良い。点列状に照射する際の、点間の間隔は、広すぎると磁区細分化効果が小さくなるので、0.01〜1.0mmが好適である。 [[Electron beam irradiation conditions]]
When irradiating an electron beam (hereinafter, also simply referred to as a beam), the conditions, that is, acceleration voltage E (V), beam current I (A), scanning speed V (m / s), beam diameter d (mm), etc. Is not particularly limited, and may be combined so as to satisfy the parameters of the present invention. The rolling direction width of the strain region can be controlled by the size of the beam diameter, and the depth in the plate thickness direction of the strain region can be controlled mainly by the energy input amount (E × I / V) per unit length of scanning the beam. Further, in order to sufficiently obtain the magnetic domain subdivision effect, the energy input amount (E × I / V) is preferably larger than 2 W · s / m. Further, it is desirable that the degree of vacuum at the time of electron beam irradiation is 2 Pa or less. If the degree of vacuum is worse than this (more than 2 Pa), the residual gas existing between the electron gun and the steel sheet deteriorates the electron beam quality, the energy introduced into the steel sheet becomes smaller, and the magnetic domain is subdivided as expected. This is because the effect cannot be obtained.
The electron beam may be continuously irradiated on the steel plate or may be irradiated in a dot sequence. The method of introducing distortion into a point sequence is to quickly scan the beam, stop at predetermined time intervals, continue to irradiate the beam at that point for a time that meets the requirements of the present invention, and then start scanning again. The process can be repeated. To realize this process with electron beam irradiation, the deflection voltage of the electron beam may be changed by using a large-capacity amplifier. When irradiating in a dot sequence, if the distance between the points is too wide, the magnetic domain subdivision effect will be small, so 0.01 to 1.0 mm is preferable.

［［レーザビーム照射条件］］
レーザビーム（以下単にレーザともいう）を照射する場合は、その条件、すなわち、鋼板に照射するレーザの平均出力Ｐ（W）やレーザの走査速度Ｖ（m/s）、レーザの径ｄ（mm）などは特に制限はなく、本発明のパラメータを充足するように組み合わせればよい。歪み領域の圧延方向幅はレーザの径の大きさ、歪領域の板厚方向深さは主にレーザを走査する単位長さ当たりのエネルギー入熱量（Ｐ/Ｖ）で制御することができる。さらに、磁区細分化効果を十分に得るためには、エネルギー入熱量（Ｐ/Ｖ）は２W・s/mより大きいことが好ましい。また、鋼板へのレーザ照射は線状に連続照射しても、点列状にパルス照射してもよい。なお、パルス間隔としては0.01〜1.0mmが好適である。 [[Laser beam irradiation conditions]]
When irradiating a laser beam (hereinafter, also simply referred to as a laser), the conditions are that the average output P (W) of the laser irradiating the steel plate, the scanning speed V (m / s) of the laser, and the diameter d (mm) of the laser. ) Etc. are not particularly limited and may be combined so as to satisfy the parameters of the present invention. The rolling direction width of the strain region can be controlled by the size of the diameter of the laser, and the depth in the plate thickness direction of the strain region can be controlled mainly by the energy input amount (P / V) per unit length of scanning the laser. Further, in order to sufficiently obtain the magnetic domain subdivision effect, the energy input amount (P / V) is preferably larger than 2 W · s / m. Further, the laser irradiation on the steel sheet may be continuous linear irradiation or pulse irradiation in a dotted line. The pulse interval is preferably 0.01 to 1.0 mm.

上記したレーザおよび電子ビームのスポット径は、より好ましくは、0.01〜0.4mm程度である。また、圧延方向の繰り返し間隔は３〜15mm程度、照射方向は、鋼板の圧延方向に対して、60〜120°程度の角度が好ましく、より好ましくは85〜95°である。 The spot diameter of the above-mentioned laser and electron beam is more preferably about 0.01 to 0.4 mm. The repeating interval in the rolling direction is preferably about 3 to 15 mm, and the irradiation direction is preferably an angle of about 60 to 120 ° with respect to the rolling direction of the steel sheet, more preferably 85 to 95 °.

以下、本発明に用いる鋼板の好適成分組成および本発明に用いて好ましい製造方法について述べる。なお、本発明の方向性電磁鋼板を製造する方法のうち、上記磁区細分化処理に直接関係しない条件については特に限定されない。 Hereinafter, a suitable composition of the steel sheet used in the present invention and a preferable manufacturing method used in the present invention will be described. Of the methods for manufacturing grain-oriented electrical steel sheets of the present invention, the conditions that are not directly related to the magnetic domain subdivision treatment are not particularly limited.

［成分組成］
本発明において、方向性電磁鋼板用スラブの成分組成は、二次再結晶が生じる成分組成であればよい。また、インヒビターを利用する場合、例えばAlＮ系インヒビターを利用する場合であればAlおよびＮを、またMnＳ・MnSe系インヒビターを利用する場合であればMnとSeおよび／またはＳを適量含有させればよい。勿論、両インヒビターを併用してもよい。この場合におけるAl、Ｎ、ＳおよびSeの好適含有量は、それぞれ、Al：0.01〜0.065質量％、Ｎ：0.005〜0.012質量％、Ｓ：0.005〜0.03質量％、Se：0.005〜0.03質量％である。なお、仕上げ焼鈍においてAl、Ｎ、ＳおよびSeは純化され、それぞれ不可避的不純物程度の含有量に低減される。 [Ingredient composition]
In the present invention, the component composition of the slab for grain-oriented electrical steel sheets may be any component composition that causes secondary recrystallization. Further, when an inhibitor is used, for example, when an AlN-based inhibitor is used, Al and N are contained, and when an MnS / MnSe-based inhibitor is used, Mn and Se and / or S are contained in appropriate amounts. good. Of course, both inhibitors may be used in combination. In this case, the preferable contents of Al, N, S and Se are Al: 0.01 to 0.065% by mass, N: 0.005 to 0.012% by mass, S: 0.005 to 0.03% by mass and Se: 0.005 to 0.03% by mass, respectively. be. In the finish annealing, Al, N, S and Se are purified and each of them is reduced to the content of unavoidable impurities.

さらに、本発明は、Al、Ｎ、ＳおよびSeの含有量を制限した、インヒビターを使用しない方向性電磁鋼板にも適用することができる。この場合、Al、Ｎ、ＳおよびSe量はそれぞれ、Al：100質量ppm以下、Ｎ：50質量ppm以下、Ｓ：50質量ppm以下およびSe：50質量ppm以下に抑制することが好ましい。 Furthermore, the present invention can also be applied to grain-oriented electrical steel sheets that do not use inhibitors and have limited contents of Al, N, S and Se. In this case, the amounts of Al, N, S and Se are preferably suppressed to Al: 100 mass ppm or less, N: 50 mass ppm or less, S: 50 mass ppm or less and Se: 50 mass ppm or less, respectively.

その他の基本成分および任意添加成分について述べると、次のとおりである。
Ｃ：0.08質量％以下
Ｃ量が0.08質量％を超えると製造工程中に磁気時効の起こらない50質量ppm以下までＣを低減することが困難になるため、0.08質量％以下とすることが好ましい。なお、下限に関しては、Ｃを含まない素材でも二次再結晶が可能であるので特に設ける必要はなく、０質量％でよい。なお、脱炭焼鈍においてＣは鋼中から除去され、不可避的不純物程度の含有量に低減される。 The other basic components and optional additive components are as follows.
C: 0.08% by mass or less If the amount of C exceeds 0.08% by mass, it becomes difficult to reduce C to 50% by mass or less, which does not cause magnetic aging during the manufacturing process. Therefore, it is preferably 0.08% by mass or less. As for the lower limit, since secondary recrystallization is possible even with a material containing no C, it is not necessary to provide it in particular, and 0% by mass may be used. In decarburization annealing, C is removed from the steel and the content is reduced to the extent of unavoidable impurities.

Si：2.0〜8.0質量％
Siは、鋼の電気抵抗を高め、鉄損を改善するのに有効な元素であるが、含有量が2.0質量％に満たないと十分な鉄損低減効果が達成できず、一方、8.0質量％を超えると加工性が著しく低下し、また磁束密度も低下するため、Si量は2.0〜8.0質量％の範囲とすることが好ましい。 Si: 2.0-8.0% by mass
Si is an element effective in increasing the electrical resistance of steel and improving iron loss, but if the content is less than 2.0% by mass, a sufficient iron loss reduction effect cannot be achieved, while 8.0% by mass. If it exceeds, the workability is remarkably lowered and the magnetic flux density is also lowered. Therefore, the amount of Si is preferably in the range of 2.0 to 8.0% by mass.

Mn：0.005〜1.0質量％
Mnは、熱間加工性を良好にする上で必要な元素であるが、含有量が0.005質量％未満ではその添加効果に乏しく、一方1.0質量％を超えると製品板の磁束密度が低下するため、 Mn量は0.005〜1.0質量％の範囲とすることが好ましい。 Mn: 0.005 to 1.0% by mass
Mn is an element necessary for improving hot workability, but if the content is less than 0.005% by mass, its addition effect is poor, while if it exceeds 1.0% by mass, the magnetic flux density of the product plate decreases. , The amount of Mn is preferably in the range of 0.005 to 1.0% by mass.

上記の基本成分以外に、磁気特性改善成分として、次に述べる元素を適宜含有させることができる。
Ni：0.03〜1.50質量％、Sn：0.01〜1.50質量％、Sb：0.005〜1.50質量％、Cu：0.03〜3.0質量％、Ｐ：0.03〜0.50質量％、Mo:0.005〜0.10質量％およびCr:0.03〜1.50質量％のうちから選んだ少なくとも１種 In addition to the above basic components, the following elements can be appropriately contained as magnetic property improving components.
Ni: 0.03 to 1.50% by mass, Sn: 0.01 to 1.50% by mass, Sb: 0.005 to 1.50% by mass, Cu: 0.03 to 3.0% by mass, P: 0.03 to 0.50% by mass, Mo: 0.005 to 0.10% by mass and Cr: At least one selected from 0.03 to 1.50% by mass

Niは、熱延板組織を改善して磁気特性を向上させるために有用な元素である。しかしながら、含有量が0.03質量％未満では磁気特性の向上効果が小さく、一方1.50質量％を超えると二次再結晶が不安定になり磁気特性が劣化する。そのため、Ni量は0.03〜1.50質量％の範囲とするのが好ましい。 Ni is an element useful for improving the hot-rolled plate structure and improving the magnetic properties. However, if the content is less than 0.03% by mass, the effect of improving the magnetic characteristics is small, while if it exceeds 1.50% by mass, the secondary recrystallization becomes unstable and the magnetic characteristics deteriorate. Therefore, the amount of Ni is preferably in the range of 0.03 to 1.50% by mass.

また、Sn、Sb、Cu、Ｐ、MoおよびCrはそれぞれ磁気特性の向上に有用な元素であるが、いずれも上記した各成分の下限に満たないと、磁気特性の向上効果が小さい。一方、上記した各成分の上限量を超えると、二次再結晶粒の発達が阻害される。そのため、それぞれ上記の範囲で含有させることが好ましい。なお、上記成分以外の残部は、製造工程において混入する不可避的不純物およびFeである。 Further, Sn, Sb, Cu, P, Mo and Cr are each useful elements for improving the magnetic properties, but if all of them do not meet the lower limit of each of the above-mentioned components, the effect of improving the magnetic properties is small. On the other hand, if the upper limit of each component described above is exceeded, the development of secondary recrystallized grains is inhibited. Therefore, it is preferable to contain each in the above range. The rest other than the above components are unavoidable impurities and Fe mixed in the manufacturing process.

次に、本発明の方向性電磁鋼板の製造方法について説明する。
［加熱］
上記した成分組成を有するスラブは、常法に従い加熱する。加熱温度は、1150〜1450℃の範囲が好ましい。 Next, the method for manufacturing the grain-oriented electrical steel sheet of the present invention will be described.
[heating]
The slab having the above-mentioned composition is heated according to a conventional method. The heating temperature is preferably in the range of 1150 to 1450 ° C.

［熱間圧延］
上記加熱後に、熱間圧延を行う。鋳造後、加熱せずに直ちに熱間圧延を行ってもよい。薄鋳片の場合には、直ちに熱間圧延を行うこととしてもよく、あるいは、熱間圧延を省略することとしてもよい。
熱間圧延を実施する場合は、粗圧延最終パスの圧延温度を900℃以上、仕上げ圧延最終パスの圧延温度を700℃以上で実施することが好ましい。 [Hot rolling]
After the above heating, hot rolling is performed. After casting, hot rolling may be performed immediately without heating. In the case of thin slabs, hot rolling may be performed immediately, or hot rolling may be omitted.
When hot rolling is carried out, it is preferable to carry out the rolling temperature of the rough rolling final pass at 900 ° C. or higher and the rolling temperature of the finish rolling final pass at 700 ° C. or higher.

［熱延板焼鈍］
熱間圧延後、必要に応じて熱延板焼鈍を施す。このとき、ゴス組織を製品板において高度に発達させるためには、熱延板焼鈍温度として800〜1100℃の範囲が好適である。熱延板焼鈍温度が800℃未満であると、熱間圧延でのバンド組織が残留し、整粒した一次再結晶組織を実現することが困難になり、二次再結晶の発達が阻害される。一方、熱延板焼鈍温度が1100℃を超えると、熱延板焼鈍後の粒径が粗大化しすぎるために、整粒した一次再結晶組織の実現が極めて困難となる。 [Annealed hot-rolled plate]
After hot rolling, hot-rolled sheet is annealed as necessary. At this time, in order to develop the Goth structure in the product plate to a high degree, the hot-rolled plate annealing temperature in the range of 800 to 1100 ° C. is suitable. When the hot-rolled plate annealing temperature is less than 800 ° C., the band structure in hot rolling remains, it becomes difficult to realize a sized primary recrystallization structure, and the development of secondary recrystallization is hindered. .. On the other hand, when the hot-rolled plate annealing temperature exceeds 1100 ° C., the particle size after hot-rolled plate annealing becomes too coarse, and it becomes extremely difficult to realize a sized primary recrystallized structure.

［冷間圧延］
熱間圧延または熱延板焼鈍後、１回または中間焼鈍を挟む２回以上の冷間圧延を施す。中間焼鈍温度は800℃以上1150℃以下が好適である。また、中間焼鈍時間は、10〜100sec程度とすることが好ましい。 [Cold rolling]
After hot rolling or hot rolling plate annealing, cold rolling is performed once or two or more times with intermediate annealing sandwiched between them. The intermediate annealing temperature is preferably 800 ° C or higher and 1150 ° C or lower. The intermediate annealing time is preferably about 10 to 100 sec.

［脱炭焼鈍］
冷間圧延後、脱炭焼鈍を行う。脱炭焼鈍では、焼鈍温度：750〜900℃、酸化性雰囲気PH₂O/PH₂：0.25〜0.60および焼鈍時間：50〜300sec程度とすることが好ましい。 [Decarburization annealing]
After cold rolling, decarburization annealing is performed. For decarburization annealing, it is preferable that the annealing temperature is 750 to 900 ° C., the oxidizing atmosphere PH ₂ O / PH ₂ : 0.25 to 0.60, and the annealing time is about 50 to 300 sec.

［焼鈍分離剤の塗布］
脱炭焼鈍後、焼鈍分離剤を塗布する。焼鈍分離剤は、主成分をMgOとし、塗布量を8〜15g/m²程度とすることが好適である。 [Applying annealing separator]
After decarburization and annealing, an annealing separator is applied. It is preferable that the main component of the annealing separator is MgO and the coating amount is ^{about 8 to 15 g / m 2.}

［仕上げ焼鈍］
焼鈍分離剤の塗布後、二次再結晶およびフォルステライト被膜の形成を目的として仕上げ焼鈍を施す。かかる仕上げ焼鈍は常法によればよいが、焼鈍温度は1100℃以上、焼鈍時間は30分以上とすることが好ましい。 [Finishing annealing]
After the application of the annealing separator, finish annealing is performed for the purpose of secondary recrystallization and formation of a forsterite film. Such finish annealing may be carried out by a conventional method, but it is preferable that the annealing temperature is 1100 ° C. or higher and the annealing time is 30 minutes or longer.

［平坦化処理および絶縁コーティング］
最終の仕上げ焼鈍後には、平坦化焼鈍を行って形状を矯正することが有効である。平坦化焼鈍は、焼鈍温度：750〜950℃および焼鈍時間：10〜200sec程度で実施するのが好ましい。
なお、本発明では、平坦化焼鈍前または後に、鋼板表面に絶縁コーティングを施す。ここでの絶縁コーティングとは、鉄損低減のために、鋼板に張力を付与するコーティング（張力コーティング）を意味する。張力コーティングとしては、シリカを含有する無機系コーティングや、物理蒸着法、化学蒸着法等によるセラミックコーティング等が挙げられる。 [Flatration and insulation coating]
After the final finish annealing, it is effective to perform flattening annealing to correct the shape. The flattening annealing is preferably carried out at an annealing temperature of 750 to 950 ° C. and an annealing time of about 10 to 200 sec.
In the present invention, an insulating coating is applied to the surface of the steel sheet before or after flattening and annealing. The insulating coating here means a coating (tension coating) that applies tension to a steel sheet in order to reduce iron loss. Examples of the tension coating include an inorganic coating containing silica and a ceramic coating by a physical vapor deposition method, a chemical vapor deposition method, or the like.

［磁区細分化処理］
以上の工程の後に、本発明の特徴の１つである磁区細分化処理を施す。かかる磁区細分化処理の条件は、前述したとおり、本発明で規定する条件に従うことが肝要である。
特に、レーザ照射あるいは電子ビーム照射により、鋼板片面に、圧延方向を横切る向きに線状に延びかつ圧延方向に間隔を置いて並ぶ、複数本の線状歪み領域を導入するに際し、上記線状歪み領域を圧延方向断面積の異なる少なくとも２種とし、上記線状歪み領域において、最も大きい圧延方向断面積をＡ（mm²）および最も小さい圧延方向断面積をＢ（mm²）とするとき、｛（Ａ−Ｂ）／Ａ｝×１００が20％以上90％以下の範囲となるようにかかるレーザ照射あるいは電子ビーム照射の照射条件を制御することが重要である。
また、前記面積Ａを有する線状歪み領域および前記面積Ｂを有する線状歪み領域を圧延方向に交互に繰り返して鋼板片面に備えるようレーザ照射あるいは電子ビーム照射の条件を制御することが好ましい。 [Magnetic domain subdivision processing]
After the above steps, a magnetic domain subdivision process, which is one of the features of the present invention, is performed. As described above, it is important that the conditions for the magnetic domain subdivision treatment follow the conditions specified in the present invention.
In particular, when introducing a plurality of linear strain regions extending linearly in a direction crossing the rolling direction and lining up at intervals in the rolling direction on one surface of a steel plate by laser irradiation or electron beam irradiation, the above linear strain is introduced. When there are at least two regions with different rolling direction cross-sectional areas, and the largest rolling direction cross-sectional area is A (mm ² ) and the smallest rolling direction cross-sectional area is B (mm ² ) in the linear strain region, { It is important to control the irradiation conditions of such laser irradiation or electron beam irradiation so that (AB) / A} × 100 is in the range of 20% or more and 90% or less.
Further, it is preferable to control the conditions of laser irradiation or electron beam irradiation so that the linear strain region having the area A and the linear strain region having the area B are alternately repeated in the rolling direction to be provided on one side of the steel sheet.

（実施例１）
Si:3.4質量％、Mn:0.1質量％、Ni:0.2質量％、Al:240質量ppm、Ｓ:20質量ppm、Ｃ: 0.07質量％、Ｎ:90質量ppmおよびSe：180質量ppmを含有し、残部はFeおよび不可避的不純物の組成からなる鋼スラブを、連続鋳造にて製造し、1430℃に加熱後、熱間圧延により板厚：2.4mmの熱延板としたのち、1100℃で20秒の熱延板焼鈍を施した。かかる熱延板焼鈍後の鋼板を、冷間圧延により中間板厚：0.40mmとし、酸化度PH₂O/PH₂=0.40、温度：1000℃、時間：70秒の条件で中間焼鈍を実施した。その後、かかる中間焼鈍後の鋼板を、塩酸酸洗により表面のサブスケールを除去したのち、再度、冷間圧延を実施して、板厚：0.23mmの冷延板とした。ついで、該冷延板を、酸化度PH₂O/PH₂=0.44、均熱温度：820℃で300秒保持する脱炭焼鈍を施した後、MgOを主成分とする焼鈍分離剤を塗布し、二次再結晶、フォルステライト被膜形成および純化を目的とした最終仕上げ焼鈍を1160℃で10h保持する条件で実施した。そして、かかる最終仕上げ焼鈍後の鋼板に、60％のコロイダルシリカとリン酸アルミニウムからなる絶縁コートを塗布、850℃にて焼付けた。このコーティング塗布処理は、平坦化焼鈍も兼ねている。
上記の手順で得た方向性電磁鋼板コイルの磁気特性を調査したところ、W_13/50:0.45W/kg、B₈:1.925TおよびW_17/50:0.83 W/kgであった。
次に、表３−１に示す照射条件にて、電子ビーム照射による、磁区細分化処理を行った。コイル幅1200mmに対して電子ビーム照射装置４台を１列とした装置セットを、２列コイル進行方向に並べ、それぞれの列で照射条件を調整した。
500ｍｍ角の試料にて単板磁気測定を行い、低い磁化領域での磁気特性W_13/50、鋼板グレードを決める特性W_17/50、高い磁化領域での磁気特性B₈をそれぞれ測定した。 (Example 1)
Contains Si: 3.4% by mass, Mn: 0.1% by mass, Ni: 0.2% by mass, Al: 240% by mass, S: 20% by mass, C: 0.07% by mass, N: 90% by mass and Se: 180% by mass. A steel slab consisting of Fe and unavoidable impurities is manufactured by continuous casting, heated to 1430 ° C, hot-rolled to make a hot-rolled plate with a thickness of 2.4 mm, and then 20 at 1100 ° C. The heat-rolled plate was annealed for a second. The steel sheet after such hot-rolled sheet annealing was subjected to intermediate annealing under the conditions of an intermediate sheet thickness of 0.40 mm by cold rolling, an oxidation degree of PH ₂ O / PH ₂ = 0.40, a temperature of 1000 ° C., and a time of 70 seconds. .. Then, the surface subscale of the steel sheet after the intermediate annealing was removed by pickling with hydrochloric acid, and then cold rolling was performed again to obtain a cold-rolled sheet having a plate thickness of 0.23 mm. Then, the cold-rolled plate was _{subjected to decarburization annealing by holding it at an oxidation degree of PH 2} O / PH ₂ = 0.44 and a soaking temperature of 820 ° C for 300 seconds, and then an annealing separator containing MgO as a main component was applied. The final finish annealing for the purpose of secondary recrystallization, forsterite film formation and purification was carried out at 1160 ° C. under the condition of holding for 10 hours. Then, an insulating coat made of 60% colloidal silica and aluminum phosphate was applied to the steel sheet after the final finish annealing, and baked at 850 ° C. This coating coating process also serves as flattening annealing.
When checking magnetic properties of grain-oriented electrical steel sheet coil obtained in the above _{procedure, W 13/50: 0.45W / kg,} B 8: 1.925T and W _17/50: was 0.83 W / kg.
Next, the magnetic domain subdivision treatment was performed by electron beam irradiation under the irradiation conditions shown in Table 3-1. A device set in which four electron beam irradiation devices were arranged in one row for a coil width of 1200 mm was arranged in the traveling direction of the two-row coil, and the irradiation conditions were adjusted in each row.
Performed veneer magnetic measurements in a sample of 500mm square, the magnetic characteristics of a low magnetization region W _13/50, characteristics W _17/50 decide steel grade, magnetic characteristics were measured B ₈ at high magnetization regions, respectively.

表３−２に、磁気測定結果を記載する。なお、低い磁化領域と高い磁化領域での磁気特性が両立しているかの判定として、以下の条件で整理した。
"◎"：W_13/50≦0.38W/kgかつB₈≧1.920TかつW_17/50≦0.73W/kg
"○"：◎の判定を満たさないかつW_13/50≦0.40W/kgかつB₈≧1.915TかつW_17/50≦0.75W/kg
"×1"：W_13/50＞0.40W/kg
"×2"：B₈＜1.915T Table 3-2 shows the magnetic measurement results. In addition, as a judgment as to whether the magnetic characteristics in the low magnetization region and the high magnetization region are compatible, the following conditions are arranged.
_{"◎": W 13/50 ≦ 0.38W} / kg and B ₈ ≧ 1.920T and W _17/50 ≦ 0.73W / kg
"○": ◎ Not satisfy the judgment and W _13/50 ≦ 0.40W / kg and B ₈ ≧ 1.915T and W _17/50 ≦ 0.75W / kg
_{"× 1": W 13/50>} 0.40W / kg
"× 2": B ₈ <1.915T

歪み領域IとII（歪み領域IをＡ、歪み領域IIをＢとする）のビ―ム照射条件が同じ条件１〜３では、低い磁化領域あるいは高い磁化領域の磁気特性が劣り、低い磁化領域と高い磁化領域の磁気特性を両立できていない。また、領域Iと領域IIの圧延方向の断面積差が、20％を下回っている条件４では高い磁化領域の磁気特性が劣り、90％を超えている条件12では低い磁化領域の磁気特性が劣り、いずれも低い磁化領域と高い磁化領域の磁気特性を両立できていない。
一方、本発明に適合する条件５〜11では、いずれの条件も、低い磁化領域および高い磁化領域の磁気特性に優れ、低い磁化領域と高い磁化領域の磁気特性を両立できていた。 Under conditions 1 to 3 where the beam irradiation conditions of the strain region I and II (the strain region I is A and the strain region II is B) are the same, the magnetic characteristics of the low magnetization region or the high magnetization region are inferior, and the low magnetization region is inferior. And the magnetic characteristics in the high magnetization region cannot be achieved at the same time. Further, under the condition 4 where the cross-sectional area difference between the region I and the region II in the rolling direction is less than 20%, the magnetic characteristics of the high magnetization region are inferior, and under the condition 12 where the difference is more than 90%, the magnetic characteristics of the low magnetization region are poor. Inferior, neither of them can achieve both the magnetic characteristics of the low magnetization region and the magnetic characteristics of the high magnetization region.
On the other hand, under the conditions 5 to 11 suitable for the present invention, the magnetic characteristics of the low magnetization region and the high magnetization region were excellent, and the magnetic characteristics of the low magnetization region and the high magnetization region could be compatible with each other.

（実施例２）
実施例1と同様の手順で得られた方向性電磁鋼板コイルに対し、表４−１に示す照射条件にて、レーザ照射による、磁区細分化処理を行った。コイル幅1200mmに対してレーザ照射装置２台を１列とした装置セットを、２列コイル進行方向に並べ、それぞれの列で照射条件を調整した。
500ｍｍ角の試料にて単板磁気測定を行い、低い磁化領域での磁気特性W_13/50、鋼板グレードを決める特性W_17/50、高い磁化領域での磁気特性B₈をそれぞれ測定した。 (Example 2)
The grain-oriented electrical steel sheet coil obtained by the same procedure as in Example 1 was subjected to magnetic domain subdivision treatment by laser irradiation under the irradiation conditions shown in Table 4-1. A device set in which two laser irradiation devices were arranged in one row for a coil width of 1200 mm was arranged in the traveling direction of the two-row coil, and the irradiation conditions were adjusted in each row.
Performed veneer magnetic measurements in a sample of 500mm square, the magnetic characteristics of a low magnetization region W _13/50, characteristics W _17/50 decide steel grade, magnetic characteristics were measured B ₈ at high magnetization regions, respectively.

表４−２に、上記磁気測定結果を記載する。なお、低い磁化領域と高い磁化領域での磁気特性が両立しているかの判定として、以下の条件で整理した。
"◎"：W_13/50≦0.38W/kgかつB₈≧1.920TかつW_17/50≦0.73W/kg
"○"：◎の判定を満たさないかつW_13/50≦0.40W/kgかつB₈≧1.915TかつW_17/50≦0.75W/kg
"×1"：W_13/50＞0.40W/kg
"×2"：B₈＜1.915T Table 4-2 shows the magnetic measurement results. In addition, as a judgment as to whether the magnetic characteristics in the low magnetization region and the high magnetization region are compatible, the following conditions are arranged.
_{"◎": W 13/50 ≦ 0.38W} / kg and B ₈ ≧ 1.920T and W _17/50 ≦ 0.73W / kg
"○": ◎ Not satisfy the judgment and W _13/50 ≦ 0.40W / kg and B ₈ ≧ 1.915T and W _17/50 ≦ 0.75W / kg
_{"× 1": W 13/50>} 0.40W / kg
"× 2": B ₈ <1.915T

歪み領域IとII（歪み領域IをＡ、歪み領域IIをＢとする）のレーザ照射条件が同じ条件１〜３では、低い磁化領域あるいは高い磁化領域の磁気特性が劣り、低い磁化領域と高い磁化領域の磁気特性を両立できていない。また、領域Iと領域IIの圧延方向の断面積差が、20％を下回っている条件４では高い磁化領域の磁気特性が劣り、90％を超えている条件12では低い磁化領域の磁気特性が劣り、いずれも低い磁化領域と高い磁化領域の磁気特性を両立できていない。
一方、本発明に適合する条件５〜11では、低い磁化領域および高い磁化領域の磁気特性に優れ、低い磁化領域と高い磁化領域の磁気特性を両立できていた。

Under conditions 1 to 3 where the laser irradiation conditions of the strain region I and II (the strain region I is A and the strain region II is B) are the same, the magnetic characteristics of the low magnetization region or the high magnetization region are inferior, and the low magnetization region and the high magnetization region are high. The magnetic properties in the magnetization region cannot be compatible. Further, under the condition 4 where the cross-sectional area difference between the region I and the region II in the rolling direction is less than 20%, the magnetic characteristics of the high magnetization region are inferior, and under the condition 12 where the difference is more than 90%, the magnetic characteristics of the low magnetization region are poor. Inferior, neither of them can achieve both the magnetic characteristics of the low magnetization region and the magnetic characteristics of the high magnetization region.
On the other hand, under the conditions 5 to 11 suitable for the present invention, the magnetic characteristics of the low magnetization region and the high magnetization region were excellent, and the magnetic characteristics of the low magnetization region and the high magnetization region could be compatible with each other.

Claims

鋼板片面に、圧延方向を横切る向きに線状に延びかつ圧延方向に間隔を置いて並ぶ、複数本の線状歪み領域を有する方向性電磁鋼板であって、
上記線状歪み領域は、圧延方向断面積の異なる少なくとも２種を有し、上記線状歪み領域において、最も大きい圧延方向断面積をＡ（mm²）および最も小さい圧延方向断面積をＢ（mm²）とするとき、｛（Ａ−Ｂ）／Ａ｝×１００が20％以上90％以下であって、かつ前記面積Ａを有する線状歪み領域および前記面積Ｂを有する線状歪み領域を圧延方向に交互に繰り返して備える方向性電磁鋼板。 A grain-oriented electrical steel sheet having a plurality of linear strain regions extending linearly in a direction crossing the rolling direction and arranging at intervals in the rolling direction on one side of the steel sheet.
The linear strain region has at least two types having different rolling direction cross-sectional areas, and in the linear strain region, the largest rolling direction cross-sectional area is A (mm ² ) and the smallest rolling direction cross-sectional area is B (mm). when a ^2), the {(a-B) / a } × I 100 20% to 90% der, and linear distortion region having a linear strain region and the area B having the area a A directional electromagnetic steel plate that is repeatedly prepared in the rolling direction.

請求項１に記載の方向性電磁鋼板を製造する方法であって、
レーザビーム照射あるいは電子ビーム照射により、鋼板片面に、圧延方向を横切る向きに線状に延びかつ圧延方向に間隔を置いて並ぶ、複数本の線状歪み領域を導入するに際し、
上記線状歪み領域として圧延方向断面積の異なる少なくとも２種を導入し、かつ上記線状歪み領域において、最も大きい圧延方向断面積をＡ（mm²）および最も小さい圧延方向断面積をＢ（mm²）とするとき、｛（Ａ−Ｂ）／Ａ｝×１００が20％以上90％以下の範囲とし、前記面積Ａを有する線状歪み領域および前記面積Ｂを有する線状歪み領域を圧延方向に交互に繰り返して鋼板片面に備えるよう上記レーザビーム照射あるいは電子ビーム照射の照射を行う方向性電磁鋼板の製造方法。 The method for manufacturing a grain-oriented electrical steel sheet according to claim 1.
When introducing a plurality of linear strain regions on one side of a steel sheet by laser beam irradiation or electron beam irradiation, which extend linearly in a direction crossing the rolling direction and are lined up at intervals in the rolling direction.
At least two types having different rolling direction cross-sectional areas are introduced as the linear strain region, and in the linear strain region, the largest rolling direction cross-sectional area is A (mm ² ) and the smallest rolling direction cross-sectional area is B (mm). ² ), {(AB) / A} × 100 is in the range of 20% or more and 90% or less, and the linear strain region having the area A and the linear strain region having the area B are rolled. A method for manufacturing a directional electromagnetic steel sheet in which the above-mentioned laser beam irradiation or electron beam irradiation is performed so as to prepare one side of the steel sheet by repeating it alternately in the direction.