JP2703468B2 - Stable manufacturing method of high magnetic flux density unidirectional electrical steel sheet - Google Patents
Stable manufacturing method of high magnetic flux density unidirectional electrical steel sheetInfo
- Publication number
- JP2703468B2 JP2703468B2 JP4290671A JP29067192A JP2703468B2 JP 2703468 B2 JP2703468 B2 JP 2703468B2 JP 4290671 A JP4290671 A JP 4290671A JP 29067192 A JP29067192 A JP 29067192A JP 2703468 B2 JP2703468 B2 JP 2703468B2
- Authority
- JP
- Japan
- Prior art keywords
- annealing
- secondary recrystallization
- hot
- rolling
- sheet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Manufacturing Of Steel Electrode Plates (AREA)
- Soft Magnetic Materials (AREA)
- Metal Rolling (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は、軟磁性材料として電気
機器の鉄心に用いられる、磁束密度の高い一方向性電磁
鋼板を連続鋳造片を出発材料として安定的に製造する方
法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for stably producing a unidirectional magnetic steel sheet having a high magnetic flux density, which is used as a soft magnetic material for an iron core of electric equipment, using a continuous cast piece as a starting material. .
【0002】[0002]
【従来の技術】一方向性電磁鋼板は軟磁性材料として変
圧器あるいは発電機の鉄心として使用され、磁気特性と
して磁化特性と鉄損特性が良好でなければならない。磁
化特性の良否はかけられた一定の磁場で鉄心内に誘起さ
れる磁束密度(B8で代表)の大小により決まる。磁束
密度の大きい材料は電気機器を小さくできるので望まし
い。2. Description of the Related Art A grain-oriented electrical steel sheet is used as an iron core of a transformer or a generator as a soft magnetic material, and must have good magnetizing properties and iron loss properties as magnetic properties. Quality of magnetic properties is determined by the magnitude of the magnetic flux density induced in the core at a constant magnetic field exerted (represented by B 8). A material having a high magnetic flux density is desirable because it can reduce the size of an electric device.
【0003】鉄損(W17/50で代表)は鉄心に所定
の交流磁場をかけた場合に熱として消費される電力損失
である。鉄損の良否に対しては磁束密度、板厚、不純物
量、比抵抗、結晶粒大きさの影響がある。最近、省エネ
ルギー動向を反映してこの鉄損の少ない一方向性電磁鋼
板の要求が大きくなっている。[0003] Iron loss (represented by W17 / 50 ) is a power loss consumed as heat when a predetermined alternating magnetic field is applied to an iron core. The quality of iron loss is influenced by the magnetic flux density, plate thickness, impurity amount, specific resistance, and crystal grain size. Recently, there has been an increasing demand for a grain-oriented electrical steel sheet with a small iron loss reflecting the trend of energy saving.
【0004】一方向性電磁鋼板は熱延と冷延により最終
板厚になった鋼板を仕上高温焼鈍することにより、{1
10}〈001〉方位を有する一次再結晶粒が選択的に
優先成長する、いわゆる二次再結晶によって得られる。
二次再結晶を生じさせるには、仕上高温焼鈍前の鋼板中
に微細なMnS,AlN等の析出物を存在させることに
より、仕上高温焼鈍中の{110}〈001〉方位以外
の一次再結晶粒成長を抑える(インヒビター効果)必要
がある。[0004] Unidirectional electrical steel sheets are prepared by subjecting a steel sheet having a final thickness obtained by hot rolling and cold rolling to finish high-temperature annealing to obtain a # 1 magnetic steel sheet.
Primary recrystallized grains having a 10} <001> orientation are obtained by so-called secondary recrystallization in which preferentially growing preferentially.
In order to cause secondary recrystallization, fine precipitates such as MnS and AlN are present in the steel sheet before finish high-temperature annealing, so that primary recrystallization other than the {110} <001> orientation during finish high-temperature annealing is performed. It is necessary to suppress grain growth (inhibitor effect).
【0005】二次再結晶を安定的に行わせる金属組織的
な条件として二次再結晶発現前の鋼板は、微細な析出
物(インヒビター)が均一、微細に存在する、結晶粒
が均一である、適切な一次再結晶集合組織を持つ、で
あることが知られている。[0005] As a metallographic condition for stably performing the secondary recrystallization, the steel sheet before the appearance of the secondary recrystallization has fine precipitates (inhibitors) uniformly and finely present, and the crystal grains are uniform. Having an appropriate primary recrystallization texture.
【0006】このような二次再結晶挙動を制御すること
により、正確な{110}〈001〉方位粒の割合を多
くすることによって磁束密度を高めることができる。磁
束密度の高い製品は電気機器の小型化と同時に鉄損の改
善も可能にするので、高磁束密度一方向性電磁鋼板の製
造技術の確立が重要である。代表技術として田口悟等に
よる特公昭40−15644号公報、及び特公昭51−
13469号公報記載の方法がある。[0006] By controlling such secondary recrystallization behavior, the magnetic flux density can be increased by increasing the ratio of accurate {110} <001> orientation grains. Since products with high magnetic flux density can reduce the size of electrical equipment and improve iron loss at the same time, it is important to establish a manufacturing technology for high magnetic flux density unidirectional magnetic steel sheets. As representative technologies, Japanese Patent Publication No. 40-15644 by Satoru Taguchi et al.
There is a method described in JP-A-13469.
【0007】ところで、現行の鉄鋼製品の製造におい
て、連続鋳造法はほぼ100%適用されており、方向性
電磁鋼板の製造においても同様である。しかしながら、
連続鋳造スラブを1280℃以上の高温に加熱後、熱延
により製造した鋼板を出発素材として得た成品には、し
ばしば圧延方向に連続した二次再結晶不良部(線状二次
再結晶不良と略称する)が発生し、磁性の劣る場合があ
った。By the way, in the current production of steel products, the continuous casting method is applied almost 100%, and the same applies to the production of grain-oriented electrical steel sheets. However,
After the continuous cast slab is heated to a high temperature of 1280 ° C. or higher, a product obtained by using a steel sheet manufactured by hot rolling as a starting material often has a secondary recrystallization defect portion continuous in the rolling direction (a linear secondary recrystallization defect). Abbreviation), and the magnetism was sometimes poor.
【0008】これらの対策として、M.F.Littm
anは特開昭48−53919号公報に連続鋳造スラブ
から2回の熱延工程を経て熱延板を作る技術を提案して
いる。さらに板倉昭等は特公昭50−37009号公報
において、高磁束密度一方向性珪素鋼板の製造に際して
連続鋳造したスラブから2回の熱延工程を経て熱延板を
作る技術を提案している。As a countermeasure against these, M. F. Littlem
An in Japanese Patent Application Laid-Open No. 48-53919 proposes a technique for producing a hot rolled sheet from a continuously cast slab through two hot rolling steps. Further, Akira Itakura et al. In Japanese Patent Publication No. 50-37009 proposes a technique for producing a hot-rolled sheet from a continuously cast slab through two hot-rolling steps in the production of a high magnetic flux density unidirectional silicon steel sheet.
【0009】しかしながら、これら先行技術は、いずれ
も2回の熱延工程を経て熱延板を得る技術であり、連続
鋳造による利点を充分に生かした技術とは言えない。そ
の後、連続鋳造スラブを用いた製造法として、塩崎守雄
等の特開昭53−19913号公報、松本文夫等の特開
昭54−120214号公報に示された技術が提案され
た。しかしながら、これらの技術はいずれも設備の対応
措置を新たに講ずる必要がある。However, each of these prior arts is a technique for obtaining a hot rolled sheet through two hot rolling steps, and cannot be said to be a technique that makes full use of the advantages of continuous casting. After that, as a production method using a continuously cast slab, the techniques disclosed in JP-A-53-19913 by Morio Shiozaki and JP-A-54-120214 by Fumio Matsu were proposed. However, all of these technologies require new measures for equipment.
【0010】また、これらの対策を行っても線状二次再
結晶不良の発生を完全に解決するに到っていない。すな
わち、最近では省エネルギーを目的とした低鉄損一方向
性電磁鋼板の要求が高まっているが、これに応えるため
には磁束密度を高めること、Si含有量を高めることが
重要である。[0010] Even if these measures are taken, the occurrence of linear secondary recrystallization failure has not been completely solved. That is, recently, there has been an increasing demand for low iron loss unidirectional electrical steel sheets for the purpose of energy saving. To meet this demand, it is important to increase the magnetic flux density and the Si content.
【0011】特に特公昭40−15644号公報による
技術は1回圧延法であるため製造コストが安く、高磁束
密度の一方向性電磁鋼板が得られるので、高Si化が可
能になれば、鉄損向上が大である。しかるに、この方法
においてSi含有量を高めると二次再結晶不良の発生が
急激に増加し、特にこのような高Siの場合において、
連続鋳造スラブを用いた際に発生する線状二次再結晶不
良は一層増加するため、Si量が3.0%を超えると工
業的な安定生産が極めて困難になっていた。In particular, the technique disclosed in Japanese Patent Publication No. 40-15644 is a single rolling method, so that the manufacturing cost is low and a unidirectional magnetic steel sheet with a high magnetic flux density can be obtained. Great improvement in loss. However, when the Si content is increased in this method, the occurrence of secondary recrystallization defects rapidly increases, and especially in the case of such high Si,
Since the linear secondary recrystallization failure generated when using the continuously cast slab further increases, if the Si content exceeds 3.0%, industrially stable production has been extremely difficult.
【0012】これは、板倉昭等による特開昭48−51
852号公報に述べられているようにSi含有量を増や
すと二次再結晶の発生に適切なAlNの確保が難しくな
り、特に連続鋳造スラブを用いた場合にはこの不適切な
AlNによる二次再結晶の不良がより顕著になるためと
考えられていた。This is disclosed in JP-A-48-51 by Akira Itakura et al.
As described in Japanese Patent Publication No. 852, if the Si content is increased, it becomes difficult to secure AlN suitable for the occurrence of secondary recrystallization. In particular, when a continuous cast slab is used, the secondary It was thought that the recrystallization failure became more prominent.
【0013】[0013]
【発明が解決しようとする課題】本発明は、最終冷延を
強圧下率で行う高磁束密度一方向性電磁鋼板の製造方法
において、連続鋳造スラブを用いた場合に発生する線状
二次再結晶不良を完全に防止し、特に低鉄損を狙ってS
i含有量を上げると一層増加する線状二次再結晶不良を
解決することを目的とする。SUMMARY OF THE INVENTION The present invention relates to a method for producing a high magnetic flux density unidirectional magnetic steel sheet in which final cold rolling is performed at a high rolling reduction, and a method for producing a linear secondary reusable steel sheet generated when a continuous cast slab is used. Completely prevent crystal defects, especially for low iron loss
It is an object of the present invention to solve a linear secondary recrystallization defect which is further increased when the i content is increased.
【0014】[0014]
【課題を解決するための手段】連続鋳造スラブを用いた
一方向性電磁鋼板の製造方法において発生する線状二次
再結晶不良の原因は、特開昭48−53919号公報で
指摘されているように、熱延に先だって行われるスラブ
加熱により結晶粒が過大に成長し、熱延板に大きな延伸
粒が残存することであるとされている。The cause of the linear secondary recrystallization defect which occurs in the method for producing a grain-oriented electrical steel sheet using a continuously cast slab has been pointed out in Japanese Patent Application Laid-Open No. 48-53919. As described above, it is said that crystal grains grow excessively by slab heating performed prior to hot rolling, and large stretched grains remain in the hot rolled sheet.
【0015】そして、この考え方を踏襲した対策が高磁
束密度一方向性電磁鋼板についても、特公昭50−37
009号公報で提案された。本発明者等は、このように
考えられていた線状二次再結晶不良の原因の他に新たな
発生要因を見いだし、以下の発明を完成した。Measures following this concept have been applied to high magnetic flux density unidirectional electrical steel sheets.
No. 009 was proposed. The present inventors have found a new cause of occurrence in addition to the cause of the linear secondary recrystallization defect considered as described above, and have completed the following invention.
【0016】即ち、本発明の要旨は以下の通りである。That is, the gist of the present invention is as follows.
【0017】重量で、Si:3.05〜4.60%、
C:0.023〜0.095%、Mn:0.03〜0.
17%、S:0.014〜0.037%、酸可溶性A
l:0.018〜0.048%、total N:0.
0050〜0.0095%、残部:Fe及び不可避的不
純物を含む溶鋼を連続鋳造し、鋳片を1320℃以上に
加熱し、熱延し、850〜1150℃の温度域で短時間
の焼鈍を行い、圧下率80%以上の強冷延をし、脱炭焼
鈍を行い、仕上高温焼鈍時の焼き付き防止を目的とした
焼鈍分離剤を塗布し、二次再結晶を主目的とした仕上高
温焼鈍を行う一方向性電磁鋼板の製造方法において、連
続鋳造時のバルジング割れに起因する0.050%以上
のSの濃厚偏析部を少なくとも鋳片の片側については、
製品板厚の表面から53μmに対応する位置から内側に
制御した連続鋳造片を用いることを特徴とする高磁束密
度一方向性電磁鋼板の安定製造方法。Si: 3.05 to 4.60% by weight;
C: 0.023 to 0.095%, Mn: 0.03 to 0.
17%, S: 0.014-0.037%, acid soluble A
l: 0.018-0.048%, total N: 0.
Molten steel containing 0050 to 0.0095%, balance: Fe and unavoidable impurities is continuously cast, the slab is heated to 1320 ° C or higher, hot rolled, and annealed in a temperature range of 850 to 1150 ° C for a short time. The steel sheet is subjected to strong cold rolling at a rolling reduction of 80% or more, decarburization annealing, and application of an annealing separator for the purpose of preventing seizure at the time of high-temperature annealing for finishing, and high-temperature annealing for finishing mainly for secondary recrystallization. In the method for producing a grain-oriented electrical steel sheet to be performed, the concentrated segregated portion of 0.050% or more of S caused by bulging cracks during continuous casting is provided on at least one side of the slab.
A method for stably producing a high magnetic flux density unidirectional magnetic steel sheet, comprising using a continuous cast piece controlled inward from a position corresponding to 53 μm from a surface of a product sheet thickness.
【0018】連続鋳造片を、熱延に先だって加熱する
に際し、バルジング割れに起因するS濃厚偏析部を製品
板厚の表面から53μmに対応する位置から内側に制御
した鋳造側の面を加熱炉の上面側に置くことを特徴とす
る1記載の安定製造方法。When the continuous cast piece is heated prior to hot rolling, the S-rich segregated portion caused by bulging cracks is controlled inward from a position corresponding to 53 μm from the surface of the product plate, and the surface on the casting side is heated by a heating furnace. 2. The stable production method according to 1, wherein the stable production method is provided.
【0019】熱延板焼鈍の前に圧下率45%以下の冷
延を行い、かつ最終冷延後の製品板厚が0.23mm以
下であることを特徴とする1又は2記載の安定製造方
法。3. The method according to 1 or 2, wherein cold rolling is performed at a rolling reduction of 45% or less before hot-rolled sheet annealing, and the product thickness after final cold rolling is 0.23 mm or less. .
【0020】熱延板を850〜1120℃で焼鈍する
ことを特徴とする3記載の安定製造方法。The stable production method according to claim 3, wherein the hot-rolled sheet is annealed at 850 to 1120 ° C.
【0021】以下、本発明について詳細に説明する。本
発明者等は連続鋳造スラブを用いた高磁束密度一方向性
電磁鋼板の製造において発生する線状二次再結晶不良の
原因を詳細に調査し、その一部については、鉄と鋼,6
7(1981),S1201で報告した。この報告以
来、さらに研究を続けた結果、新たな知見を得て本発明
を完成した。Hereinafter, the present invention will be described in detail. The present inventors have investigated in detail the cause of linear secondary recrystallization defects that occur in the production of high magnetic flux density unidirectional magnetic steel sheets using a continuously cast slab.
7 (1981), S1201. As a result of further research since this report, the present inventors have obtained new findings and completed the present invention.
【0022】以下に本発明を詳述する。 C:0.06%、Si:3.0%、Mn:0.08%、
S:0.025%、酸可溶性Al:0.027%、T.
N:0.008%を含有する250mm厚の連続鋳造ス
ラブを約1400℃に加熱後に2.3mm厚の熱延板と
し、1120℃で3minの焼鈍後、室温まで急冷却を
行い、0.3mm厚まで冷延を行い、湿水素雰囲気で8
50℃で3minの脱炭焼鈍を行い、MgOを塗布し、
1200℃で20hrの仕上高温焼鈍を行った。Hereinafter, the present invention will be described in detail. C: 0.06%, Si: 3.0%, Mn: 0.08%,
S: 0.025%, acid-soluble Al: 0.027%,
N: A 250 mm thick continuous cast slab containing 0.008% is heated to about 1400 ° C., then turned into a 2.3 mm thick hot rolled sheet, annealed at 1120 ° C. for 3 minutes, rapidly cooled to room temperature, and cooled to 0.3 mm. Cold rolled to a thickness of 8 mm in a wet hydrogen atmosphere.
Perform decarburization annealing at 50 ° C for 3 minutes, apply MgO,
A high-temperature finish annealing at 1200 ° C. for 20 hours was performed.
【0023】線状二次再結晶不良は図1に示すように圧
延方向に連続して発生する。そこで調査として、その成
品のマクロ組織が図1に示すように正常部、線状二次再
結晶部に対応する圧延方向に隣接した脱炭焼鈍板につい
て、金属組織、集合組織を比較し、図2に結果を示す。The linear secondary recrystallization defects occur continuously in the rolling direction as shown in FIG. Therefore, as a survey, the microstructure and texture of the decarburized annealed sheet adjacent to the normal part and the linear secondary recrystallization part in the rolling direction corresponding to the normal part and the linear recrystallization part were compared as shown in FIG. 2 shows the results.
【0024】さらに仕上焼鈍の途中で試料を引き出し、
二次再結晶進行過程について金属組織の変化を観察し、
図3に結果を示す。図3に示されるように、又既に知ら
れているように、二次再結晶は表面部から発生する。Further, during the finish annealing, the sample is pulled out,
Observe the change in the metal structure during the secondary recrystallization process,
FIG. 3 shows the results. As shown in FIG. 3 and as is already known, secondary recrystallization occurs from the surface.
【0025】発生した二次再結晶粒は正常部では板厚方
向に速やかに、円滑に成長するが、線状二次再結晶不良
部では板厚1/4近傍の位置で成長が止まっている。焼
鈍がさらに進むと正常部では二次再結晶粒が一次再結晶
粒の全域を喰い、二次再結晶が完了する。The generated secondary recrystallized grains grow quickly and smoothly in the plate thickness direction in the normal portion, but stop growing at a position near the plate thickness of 1/4 in the linear secondary recrystallization defective portion. . As the annealing proceeds further, in the normal part, the secondary recrystallized grains eat the entire area of the primary recrystallized grains, and the secondary recrystallization is completed.
【0026】線状二次再結晶不良部では二次再結晶粒の
成長が遅れている間に、ゴス方位粒とは限らない表面粒
が粒成長し、最終段階まで二次再結晶粒に喰われずに残
るために二次再結晶不良になると考えられる。このよう
に、線状二次再結晶不良の直接の原因は板厚1/4近傍
の位置で成長が止まることであるので、その位置に対応
した脱炭焼鈍板での特異点を調査した。While the growth of the secondary recrystallized grains is delayed in the linear secondary recrystallization defective portion, surface grains not necessarily Goss-oriented grains grow, and are eaten by the secondary recrystallized grains until the final stage. It is considered that secondary recrystallization failure occurs because it remains without being removed. As described above, the direct cause of the linear secondary recrystallization defect is that growth stops at a position near the plate thickness of 1/4. Therefore, a singular point in the decarburized annealed plate corresponding to the position was investigated.
【0027】図2に示されるように、線状二次再結晶不
良対応部は正常部に比べ板厚1/4近傍での一次再結晶
粒径が大きく、{111}面方位粒の少ない集合組織に
なっていることが分かる。一般に、{110}方位二次
再結晶粒が成長するに際し、喰われる一次再結晶粒は小
さく、集合組織としては{111}面方位粒であること
が、その速やかな成長に有利である。従って、板厚1/
4近傍位置での一次再結晶粒径が大きく、{111}面
方位粒が少ない線状二次再結晶不良部で、二次再結晶粒
の成長が遅れることが理解できる。As shown in FIG. 2, the portion corresponding to the linear secondary recrystallization defect has a larger primary recrystallized grain size in the vicinity of 1/4 thickness and a smaller number of {111} plane orientation grains than the normal portion. You can see that it is an organization. In general, when the {110} oriented secondary recrystallized grains grow, the eaten primary recrystallized grains are small, and the {111} plane oriented grains are advantageous for the rapid growth. Therefore, the sheet thickness 1 /
It can be understood that the growth of the secondary recrystallized grains is delayed in the linear secondary recrystallization defective portion where the primary recrystallized grain size is large near the position 4 and the {111} plane orientation grains are small.
【0028】この板厚1/4近傍での金属結晶粒組織の
二つの特徴をもたらす原因を調査した。その結果、線状
二次再結晶対応部は正常部に比べ、熱延板の集合組織
として、{100}面方位が強く、{111}面方位が
弱い、延板での析出物であるMnSが大きく、かつ分
散が疎である、ことが分かった。The causes of the two characteristics of the metal grain structure in the vicinity of the plate thickness of 1/4 were investigated. As a result, as compared to the normal part, the linear secondary recrystallization corresponding part has a strong {100} plane orientation and a weak {111} plane orientation as a texture of the hot-rolled sheet. Is large and the dispersion is sparse.
【0029】特に、このMnS分散状態が疎であること
は一次再結晶粒が大きくなる原因でもあり、極めて興味
があり、連続鋳造スラブを用いた高磁束密度一方向性電
磁鋼板の製造で発生する線状二次再結晶不良原因に関す
る新規な現象である。In particular, the sparse dispersion state of MnS is also a cause of an increase in the size of primary recrystallized grains, and is extremely interesting, and is generated in the production of a high magnetic flux density unidirectional magnetic steel sheet using a continuously cast slab. This is a novel phenomenon related to the cause of linear secondary recrystallization failure.
【0030】これを実験結果で以下に示す。図4は脱炭
焼鈍板の板厚方向でのMnS分散状態の電子顕微鏡観察
結果を示す。図5は熱延板の板厚方向での集合組織を示
す。This is shown below in the experimental results. FIG. 4 shows the results of electron microscopic observation of the state of dispersion of MnS in the thickness direction of the decarburized annealed sheet. FIG. 5 shows the texture of the hot-rolled sheet in the thickness direction.
【0031】図5から線状二次再結晶不良に対応した熱
延板の集合組織で圧延方位である{100}面方位が強
く、再結晶方位である{111}面方位が弱いことか
ら、熱延板→熱延板焼鈍→冷延→脱炭焼鈍の工程で処理
した場合の脱炭焼鈍板において、再結晶がし難く、再結
晶方位である{111}面方位粒が少なくなることはよ
く理解できる。FIG. 5 shows that the {100} plane orientation, which is the rolling orientation, is strong and the {111} plane orientation, which is the recrystallization orientation, is weak in the texture of the hot rolled sheet corresponding to the linear secondary recrystallization defect. In the decarburized annealed sheet processed in the process of hot-rolled sheet → hot-rolled sheet annealing → cold rolling → decarburizing annealing, recrystallization is difficult to occur, and the number of {111} plane orientation grains, which is the recrystallization orientation, is reduced. Can understand well.
【0032】さらに、MnSの分散が疎でかつ、大きい
ことから脱炭焼鈍板での一次再結晶粒が大きくなること
も分かる。以上の研究から、線状二次再結晶不良の原因
として新たに判明した熱延板1/4近傍でのMnSが疎
で、かつ大きい原因に注目して、種々検討した。Further, it is also understood that the primary recrystallized grains in the decarburized annealed sheet are large because the dispersion of MnS is sparse and large. From the above research, various investigations were made by paying attention to the cause of the sparse and large MnS in the vicinity of the hot-rolled sheet 1/4 newly found as the cause of the linear secondary recrystallization failure.
【0033】その結果、連続鋳造スラブで、いわゆるバ
ルジングによる割れ発生に起因してSの偏析が生じ、そ
の高S領域が熱延時の加熱で溶体化しないためにMnS
の均一・微細化ができないことが分かった。As a result, segregation of S occurs in the continuously cast slab due to cracking caused by so-called bulging, and the high S region does not become a solution by heating during hot rolling, so that MnS
It was found that uniformity and fineness could not be achieved.
【0034】図6に鋳造スラブ組織と、その組織につい
てSの存在量をEPMAで測定した後に画像処理を行っ
たSの分布図を示した。FIG. 6 shows a cast slab structure and a distribution diagram of S obtained by performing image processing after measuring the abundance of S in the structure by EPMA.
【0035】これから分かるように、鋳造スラブに割れ
は見られないが、全厚1/4近傍にSの濃厚偏析帯があ
る。この部分のS量は0.050%を超えている。熱延
時の加熱で極めて溶体化し難く、たとえば本発明で限定
している最小のMnである0.03%でもMnSは溶体
化せず、熱延板のMnSは大きく、疎になる。As can be seen from the figure, no crack is observed in the cast slab, but there is a dense segregation zone of S in the vicinity of 1/4 of the total thickness. The S content in this portion exceeds 0.050%. It is extremely difficult to form a solution by heating during hot rolling. For example, even at the minimum Mn of 0.03% defined in the present invention, MnS does not form a solution, and the MnS of the hot rolled sheet becomes large and sparse.
【0036】本発明者の調査によれば、このSの濃厚偏
析は連続鋳造時にいわゆるバルジング現象(スラブ表面
が凝固し、中心部に溶鋼が残存した状態において、溶鋼
圧力により発生した既凝固部分の割れ)を起因(割れ部
分のSの濃縮した中心部の未凝固鋼が入り込む)とする
セミ・マクロ偏析である。このセミ・マクロ偏析以外
に、中心部には一般的なSの中心偏析がある。According to the investigation by the present inventor, this S segregation is caused by the so-called bulging phenomenon during continuous casting (in the state where the slab surface is solidified and the molten steel remains in the central part, the solidified portion generated by the molten steel pressure is generated). This is semi-macro segregation caused by cracking (unconsolidated steel in the central part where S in the cracked portion is concentrated enters). In addition to the semi-macro segregation, there is general central segregation of S in the center.
【0037】上記の図2の金属組織と、図4の析出物
(MnS)で示したように、板厚1/4近傍の組織が正
常部と線状二次再結晶部とで異なるので、線状二次再結
晶不良を解消するためには、成品と位置関係が一致する
セミ・マクロ偏析を適切に制御することが有効であると
考えられた。As shown by the metal structure in FIG. 2 and the precipitate (MnS) in FIG. 4, the structure in the vicinity of 板 of the plate thickness is different between the normal part and the linear secondary recrystallized part. In order to eliminate linear secondary recrystallization defects, it was considered effective to appropriately control semi-macro-segregation in which the positional relationship with the product is consistent.
【0038】特に、二次再結晶の粒成長挙動の結果か
ら、表面近傍から発生した二次再結晶粒が板厚中心側に
スムースに成長すれば線状二次再結晶不良とはならない
と考えられたので、Sの濃厚偏析帯を板厚中心側に寄せ
る条件で連続鋳造した。In particular, from the results of the grain growth behavior of the secondary recrystallization, it is considered that if the secondary recrystallized grains generated from the vicinity of the surface grow smoothly toward the center of the sheet thickness, linear secondary recrystallization failure does not occur. Therefore, continuous casting was performed under the condition that the concentrated segregation zone of S was moved toward the center of the sheet thickness.
【0039】なお、中心部にもS濃厚偏析帯はあるが、
線状二次再結晶部の結晶粒が正常部より大きいこともな
く、又集合組織的にも{222}方位が少ないこともな
いので、これが線状二次再結晶不良の原因とは考えられ
ない。Although there is an S-rich segregation zone in the center,
Since the crystal grains in the linear secondary recrystallization portion are not larger than the normal portion, and the {222} orientation is not small in texture, it is considered that this is the cause of the linear secondary recrystallization failure. Absent.
【0040】以上の考えに沿った、バルジングによるセ
ミ・マクロ偏析帯の位置は、鋳造後の冷却速度を制御す
ることにより表面側の凝固厚を調節し、溶鋼圧との関係
で変えることができる。そこで、冷却速度を調節する
に、最も一般的な鋳造速度を変えて以下の試験を行っ
た。Based on the above idea, the position of the semi-macro segregation zone due to bulging can be changed in relation to the molten steel pressure by controlling the cooling rate after casting to adjust the solidification thickness on the surface side. . Therefore, in order to adjust the cooling rate, the following tests were performed while changing the most common casting rate.
【0041】C:0.065%、Si:3.37%、M
n:0.075%、S:0.025%、酸可溶性Al:
0.030%、total N:0.00835%、残
部:Fe及び不可避的不純物、を含む溶鋼を250mm
厚のスラブに連続鋳造した。この鋳造時の引き抜き速度
を0.7,1.0m/minの2種類変えた。C: 0.065%, Si: 3.37%, M
n: 0.075%, S: 0.025%, acid-soluble Al:
250 mm of molten steel containing 0.030%, total N: 0.00835%, and balance: Fe and inevitable impurities.
It was continuously cast into thick slabs. The drawing speed at the time of casting was changed between two types, 0.7 and 1.0 m / min.
【0042】このスラブを1410℃に加熱後、2.3
mm厚の熱延板とし、1120℃で60sec焼鈍し、
急冷後、酸洗した。次に、0.30mm厚に冷延し、8
50℃で180secの脱炭焼鈍を行い、1200℃で
20hrの二次再結晶を主目的とした高温焼鈍を行っ
た。After heating this slab to 1410 ° C., 2.3
mm thick hot rolled sheet and annealed at 1120 ° C for 60 seconds,
After quenching, it was pickled. Next, cold-rolled to a thickness of 0.30 mm,
Decarburization annealing was performed at 50 ° C. for 180 seconds, and high-temperature annealing was performed at 1200 ° C. for 20 hours mainly for secondary recrystallization.
【0043】この試験では本発明の大きな狙いの一つで
ある高Siにすることにより、低鉄損を達成するために
高磁束密度一方向性電磁鋼板の製造方法としては高いS
i量である3.37%を含有させた。表1に、鋳造スラ
ブのSのセミ・マクロ偏析帯の位置と、線状二次再結晶
不良の発生状況を示した。In this test, by setting high Si, which is one of the major aims of the present invention, in order to achieve low iron loss, a high magnetic flux density unidirectional magnetic steel sheet manufacturing method is used.
3.37% which is i amount was contained. Table 1 shows the position of the semi-macro segregation zone of S in the cast slab and the occurrence state of the linear secondary recrystallization failure.
【0044】[0044]
【表1】 [Table 1]
【0045】引き抜き速度が0.7m/minであった
ものは、線状二次再結晶不良もなく良好な二次再結晶が
得られたが、1.0m/minのものは線状二次再結晶
不良が発生し、磁気特性も悪かった。この時の鋳片のS
のセミ・マクロ偏析帯は成品厚0.30mmの表面から
ほぼ37〜65μmに対応する位置となり、表面から発
生した二次再結晶粒の成長を阻害したものと思われる。
一方、0.7m/minの場合は58〜102μmの位
置となり、二次再結晶粒の成長を大きく抑制することも
なかったものと考えられる。When the drawing speed was 0.7 m / min, good secondary recrystallization was obtained without linear secondary recrystallization failure, but when the drawing speed was 1.0 m / min, the linear secondary recrystallization was good. Recrystallization failure occurred and the magnetic properties were poor. S of the slab at this time
Is located at a position corresponding to approximately 37 to 65 μm from the surface having a product thickness of 0.30 mm, which seems to have inhibited the growth of secondary recrystallized grains generated from the surface.
On the other hand, in the case of 0.7 m / min, the position is 58 to 102 μm, and it is considered that the growth of secondary recrystallized grains was not largely suppressed.
【0046】表面近傍での二次再結晶発現挙動は以下の
ように考えられる。二次再結晶発現前の綱板の結晶粒
(脱炭焼鈍板)は12〜18μm程度であるが、平均的
に最表面粒の1個下の粒から二次再結晶粒が発生し、さ
らにその二次再結晶粒の下の1個の粒が二次再結晶粒に
喰われるものとすると、表面から3個の粒の下から内側
(36〜54μm)に、Sの偏析帯に起因する二次再結
晶粒の成長抑制となる一次再結晶粒組織を調整すること
により二次再結晶が安定すると考えると、研究結果をよ
く説明できる。The secondary recrystallization onset behavior near the surface is considered as follows. The crystal grain (decarburized annealed sheet) of the steel sheet before the onset of the secondary recrystallization is about 12 to 18 μm, but secondary recrystallized grains are generated from the grain one below the outermost surface grain on average. Assuming that one grain below the secondary recrystallized grain is eaten by the secondary recrystallized grain, the grain is caused by the segregation zone of S from the bottom to the inside (36 to 54 μm) of three grains from the surface. The study results can be well explained by considering that secondary recrystallization is stabilized by adjusting the primary recrystallized grain structure that suppresses the growth of secondary recrystallized grains.
【0047】以上に解明した線状二次再結晶不良の発生
原因と、その発生原因を制御することにより発生の有・
無を作りだした実験結果から本発明はなされた。その実
施態様は以下の内容である。The cause of the linear secondary recrystallization failure clarified as described above, and the occurrence of the secondary recrystallization failure can be controlled by controlling the cause.
The present invention has been made based on the results of experiments that created nothing. The embodiment is as follows.
【0048】まず本発明の鋼成分の限定理由について述
べる。本発明で溶鋼は、転炉、電気炉等その溶製方法は
問わないが成分含有量は次の範囲に入る必要がある。C
は0.023%未満になると二次再結晶が不安定にな
り、かつ二次再結晶した場合でも磁束密度が悪いので、
0.023%以上とした。一方、Cが多くなり過ぎると
脱炭焼鈍時間が長くなり、経済的でないので0.095
%以下とした。First, the reasons for limiting the steel components of the present invention will be described. In the present invention, the molten steel is not limited to a smelting method such as a converter or an electric furnace, but the component content must be within the following range. C
Is less than 0.023%, the secondary recrystallization becomes unstable, and the magnetic flux density is poor even after the secondary recrystallization.
0.023% or more. On the other hand, if C is too large, the decarburization annealing time will be long, and it is not economical.
% Or less.
【0049】Siは4.60%を超えると冷延時の割れ
が著しくなるので4.60%以下とした。又、3.05
%未満では製品厚0.30mmでW17/50が1.0
5W/kg以下の最高級の鉄損が得られないので、本発
明での最高級一方向性電磁鋼板を得る目的に合致する
3.05%以上を範囲とした。望ましくは3.20%以
上である。If the Si content exceeds 4.60%, cracking during cold rolling becomes remarkable, so the content is set to 4.60% or less. 3.05
%, W 17/50 is 1.0 at a product thickness of 0.30 mm.
Since the highest iron loss of 5 W / kg or less cannot be obtained, the range is set to 3.05% or more, which meets the purpose of obtaining the highest grade unidirectional electrical steel sheet in the present invention. Desirably, it is at least 3.20%.
【0050】本発明では二次再結晶に必要な析出物とし
て、MnSとAlNを用いる。従って、必要最小限のM
nSを確保するためにMnが0.03%以上、Sが0.
014%以上、酸可溶性Alが0.018%以上必要で
ある。In the present invention, MnS and AlN are used as precipitates required for secondary recrystallization. Therefore, the necessary minimum M
In order to secure nS, Mn is 0.03% or more and S is 0.1%.
014% or more, and acid-soluble Al must be 0.018% or more.
【0051】Nについては0.0050%未満ではイン
ヒビターとしてのAlNが不足し二次再結晶が生じない
ので下限として0.0050%が必要であり、0.00
95%を超えるとブリスターと呼ばれる鋼板表面のふく
れが発生するので0.0095%以下とした。If N is less than 0.0050%, AlN as an inhibitor becomes insufficient and secondary recrystallization does not occur. Therefore, the lower limit is required to be 0.0050%.
If it exceeds 95%, blisters on the surface of the steel plate called blisters occur, so the content was made 0.0095% or less.
【0052】Mnが0.17%、そして酸可溶性Alが
0.048%を超えると熱延板のMnS,AlNが不適
切になり、二次再結晶が不安定になるので、Mnを0.
17%以下、酸可溶性Alを0.048%以下とした。
残りはFe及び不可避的不純物である。When Mn exceeds 0.17% and acid-soluble Al exceeds 0.048%, MnS and AlN of the hot-rolled sheet become inappropriate and secondary recrystallization becomes unstable.
17% or less, and acid-soluble Al was set to 0.048% or less.
The balance is Fe and inevitable impurities.
【0053】なお、本発明の狙いであるS濃厚偏析帯の
位置制御に影響しない元素としてSn,Sb等を添加す
ることは差し支えない。以上に述べた範囲の成分を含む
溶鋼を連続鋳造によりスラブとする。本発明の一つの目
的が連続鋳造スラブを用いることによる利点の適用にあ
るので、連続鋳造スラブが限定範囲になる。It should be noted that Sn, Sb, etc. may be added as an element which does not affect the position control of the S-rich segregation zone, which is the object of the present invention. Molten steel containing the components in the above-described ranges is formed into a slab by continuous casting. One object of the present invention is to apply the advantages of using continuous cast slabs, so that continuous cast slabs are of limited scope.
【0054】この連続鋳造スラブについて、鋳造時のバ
ルジングに起因するSのセミ・マクロ偏析帯の存在位置
を少なくとも鋳片の片側については、製品板厚の表面か
ら53μmに対応する部位から内側に制御する必要があ
る。そして、濃厚偏析帯と限定するS量は、0.03%
Mnを含む連続鋳造スラブを1320℃以上で加熱した
時に溶体化が困難な量として0.050%を規定した。In this continuous casting slab, the position of the semi-macro segregation zone of S caused by bulging during casting is controlled at least on one side of the slab to be inward from a portion corresponding to 53 μm from the surface of the product sheet thickness. There is a need to. The amount of S limited to the thick segregation zone is 0.03%
0.050% was defined as the amount of solution hardening when the continuous cast slab containing Mn was heated at 1320 ° C. or higher.
【0055】ところで、バルジングに影響する鋳造因子
は一般によく知られている。本発明で目的とするバルジ
ング位置を鋳片の中心側に制御するためには、例えば、
引き抜き速度を遅くする方法、冷却により表面の凝固厚
を調節し、合わせて溶鋼圧を小さくする方法等が採用さ
れる。Incidentally, casting factors affecting bulging are generally well known. In order to control the bulging position aimed at in the present invention to the center side of the slab, for example,
A method of reducing the drawing speed, a method of adjusting the solidified thickness of the surface by cooling, and a method of reducing the molten steel pressure in combination are adopted.
【0056】本発明では、表1で用いた成分とほぼ同等
の溶鋼を、上記方法で調節して、バルジング起因のS濃
厚偏析帯位置を変化させた250mm厚の連続鋳造スラ
ブを作成した。このスラブを1410℃で加熱後、2.
3mm,2.0mm,1.8mm厚の熱延板とし、11
20℃で60sec焼鈍し、急冷後、酸洗した。In the present invention, a continuous cast slab having a thickness of 250 mm was prepared by changing the position of the S-rich segregation zone caused by bulging by adjusting the molten steel substantially equal to the components used in Table 1 by the above method. After heating this slab at 1410 ° C., 2.
3mm, 2.0mm, 1.8mm thick hot rolled sheet, 11
Annealing was performed at 20 ° C. for 60 seconds, quenched, and then pickled.
【0057】次に、2.3mm厚材は0.30mm厚
に、2.0mm厚材は0.27mm厚に、1.8mm厚
材は0.23mm厚に冷延し、850℃で0.30mm
厚材は180sec、0.27mm厚材は160se
c、0.23mm厚材は120secの脱炭焼鈍を行
い、1200℃で20hrの二次再結晶を主目的とした
高温焼鈍を行った。Next, the 2.3 mm thick material is cold rolled to 0.30 mm thickness, the 2.0 mm thick material is cold rolled to 0.27 mm thickness, and the 1.8 mm thick material is cold rolled to 0.23 mm thickness. 30mm
180sec for thick material, 160sec for 0.27mm thick material
c, The 0.23 mm thick material was decarburized and annealed for 120 sec, and was subjected to high-temperature anneal at 1200 ° C. for 20 hours mainly for secondary recrystallization.
【0058】この成品の線状二次再結晶不良発生程度と
バルジング起因のS濃厚偏析位置(S濃厚偏析帯は幅を
持っているが、表面近傍で二次再結晶粒と最初に干渉し
あう表面側での位置を成品の表面からの距離で示す。成
品板厚が変化しても、最表面粒と二次再結晶粒と二次再
結晶粒に喰われる粒の3個の粒を足し合わせた距離は一
定であり、その距離より内側にS濃厚偏析帯があるか、
否かが線状二次再結晶不良の発生に影響するので、成品
の表面からの位置として表示した。)との関係を図7に
示した。The degree of occurrence of linear secondary recrystallization failure of this product and the position of S-rich segregation due to bulging (the S-rich segregation zone has a width, but first interferes with the secondary recrystallized grains near the surface. The position on the surface side is indicated by the distance from the surface of the product.Even if the thickness of the product changes, three grains of the top surface grain, the secondary recrystallized grain, and the grain eaten by the secondary recrystallized grain are added. The combined distance is constant, and there is an S-rich segregation zone inside the distance,
Since the presence or absence affects the occurrence of linear secondary recrystallization failure, it is indicated as a position from the surface of the product. 7) is shown in FIG.
【0059】この図から成品板厚が薄くなるほど線状二
次再結晶不良の発生が増大するが、S濃厚偏析帯位置を
表面から53μmの位置より内側に調節すれば、線状二
次再結晶不良の発生もなく良好な二次再結晶が得られ
る。From this figure, the occurrence of linear secondary recrystallization defects increases as the thickness of the product sheet decreases, but if the position of the S-rich segregation zone is adjusted inward from the position of 53 μm from the surface, the linear secondary recrystallization will occur. Good secondary recrystallization can be obtained without occurrence of defects.
【0060】ところで二次再結晶初期における{11
0}〈001〉粒の成長挙動は板厚の表と裏で等価で行
われる。従って、連続鋳造スラブとしては最低限、表と
裏のどちらかのS濃厚偏析帯を調節し、{110}〈0
01〉粒の円滑な成長を計ればよい。By the way, in the early stage of the secondary recrystallization, # 11
The growth behavior of 0} <001> grains is equivalent on the front and back of the plate thickness. Therefore, as a continuous casting slab, at least the S-rich segregation zone on either the front or the back is adjusted, and {110} <0
01> Smooth growth of grains may be measured.
【0061】次に、この連続鋳造スラブを加熱後、熱延
により熱延板とする。スラブ加熱の温度は低すぎると、
析出分散相が固溶しないため二次再結晶が不安定にな
り、さらには磁束密度が低くなるので、下限を1320
℃とした。なお、上限については加熱設備が工業的に耐
える範囲で高いほうが二次再結晶に有利であるが、設備
的に1420℃前後が限界である。Next, the continuous cast slab is heated and then hot-rolled into a hot-rolled sheet. If the slab heating temperature is too low,
Since the precipitated dispersed phase does not form a solid solution, the secondary recrystallization becomes unstable and the magnetic flux density becomes low.
° C. As for the upper limit, the higher the heating equipment is in a range that can be industrially endured, the more advantageous the secondary recrystallization is, but the upper limit is about 1420 ° C. in terms of equipment.
【0062】なお、この加熱に際しS濃厚偏析帯位置を
調節した側を温度の高くなり易い加熱炉上側にすること
は、析出物のより完全な固溶ができるため高B8が得ら
れ、望ましい。以上のようにして得られた熱延板は85
0〜1150℃の範囲で短時間の連続焼鈍を行う。焼鈍
温度が850℃未満では高磁束密度が得られず、115
0℃を超えると二次再結晶が不完全となる。It should be noted, that the side to adjust the S concentrated segregation zone located higher becomes easy furnace top temperature upon heating, high B 8 for a more complete solid solution can be a precipitate obtained, desired . The hot rolled sheet obtained as described above is 85
Short-time continuous annealing is performed in the range of 0 to 1150 ° C. If the annealing temperature is lower than 850 ° C., a high magnetic flux density cannot be obtained, and 115
If it exceeds 0 ° C., secondary recrystallization becomes incomplete.
【0063】焼鈍時間として30分を超えると生産能率
が極めて悪くなることは勿論、二次再結晶不良が発生す
る。そして、30sec未満では熱処理の効果がほとん
どなくなる。熱延板の連続焼鈍後、冷延を行う。本発明
では高磁束密度一方向性電磁鋼板を得ることを目的とし
ているので冷延圧下率として80%以上の強圧下率が必
要である。90%前後が安定して高磁束密度を得るのに
最適であり、略93%を超えると二次再結晶が不安定に
なり、また得られた二次再結晶板の磁束密度は悪くな
る。If the annealing time exceeds 30 minutes, the production efficiency becomes extremely poor, and the secondary recrystallization failure occurs. If the time is less than 30 seconds, the effect of the heat treatment is hardly obtained. After continuous annealing of the hot rolled sheet, cold rolling is performed. The purpose of the present invention is to obtain a high magnetic flux density unidirectional magnetic steel sheet, so that a cold rolling reduction of 80% or more is required as a cold rolling reduction. About 90% is optimal for stably obtaining a high magnetic flux density, and when it exceeds about 93%, secondary recrystallization becomes unstable, and the magnetic flux density of the obtained secondary recrystallized plate becomes poor.
【0064】この冷延で製品厚を作るに際し、鉄損の良
好な製品を得るために板厚を薄くすると、熱延板の板厚
も薄くせざるをえず、熱延での鋼板形状の確保が困難に
なる。また、各種製品板厚を製造するために、数多くの
板厚の熱延板を在庫として保管する必要があり不経済で
ある。In making the product thickness by this cold rolling, if the thickness is reduced in order to obtain a product with good iron loss, the thickness of the hot rolled sheet must be reduced, and the shape of the hot rolled steel sheet has to be reduced. It becomes difficult to secure. In addition, in order to manufacture various product sheet thicknesses, it is necessary to store hot-rolled sheets having a large number of sheet thicknesses as inventory, which is uneconomical.
【0065】そこで、最終製品板厚にする冷延の前段階
として、最適な最終冷延率になる板厚まで予備冷延を行
い、その後に前述の連続焼鈍を行い、そして最終冷延を
行う方法が採用できる。なお、この予備冷延としては圧
延率を高くするとその後の連続焼鈍で再結晶が完全に進
み、最終冷延の高圧下率の影響がそがれ、高磁束密度が
得られないので、圧下率として45%を超えない必要が
ある。Therefore, as a pre-stage of the cold rolling to the final product sheet thickness, preliminary cold rolling is performed to a sheet thickness at which an optimal final cold rolling rate is obtained, and then the above-described continuous annealing is performed, and final cold rolling is performed. The method can be adopted. When the rolling reduction is increased in this preliminary cold rolling, the recrystallization completely proceeds in the subsequent continuous annealing, and the influence of the high-pressure reduction rate of the final cold rolling is reduced, and a high magnetic flux density cannot be obtained. % Must not be exceeded.
【0066】ところで、熱延板は圧延長手方向で温度履
歴が異なり、結晶組織に差がある。このような熱延板に
圧延を行い、さらに焼鈍を行うと結晶組織の差がむしろ
拡大された状態で残る。そこで、予備冷延を行う際は、
均一な特性を持つ製品を得るために、850〜1120
℃の短時間の連続焼鈍を行い結晶組織を均一にすること
が望ましい。The hot rolled sheet has different temperature histories in the longitudinal direction of rolling, and has a difference in crystal structure. When such a hot-rolled sheet is rolled and further annealed, the difference in crystal structure remains in a rather enlarged state. Therefore, when performing preliminary cold rolling,
850 to 1120 to obtain a product with uniform properties
It is desirable to carry out continuous annealing at a low temperature for a short time to make the crystal structure uniform.
【0067】以上のようにして最終板厚になった鋼板は
湿水素雰囲気中で脱炭焼鈍を行う。脱炭焼鈍後の鋼板表
面には仕上高温焼鈍時の焼き付きを防止するための焼鈍
分離剤を塗布する。引き続いて二次再結晶を主目的とす
る仕上高温焼鈍を行い成品とする。The steel sheet having the final thickness as described above is subjected to decarburizing annealing in a wet hydrogen atmosphere. An annealing separator is applied to the surface of the steel sheet after the decarburizing annealing to prevent seizure at the time of finishing high-temperature annealing. Successively, finish high-temperature annealing mainly for secondary recrystallization is performed to obtain a product.
【0068】以上、詳述したように、本発明は安価に製
造でき、かつ成品長手方向の成分均一による磁性均一と
いう工業的安定生産が可能である連続鋳造スラブを出発
素材とするに際し、発生する線状二次再結晶不良(特
に、鉄損を下げるためにSiを高めると一層発生し易く
なり、高級一方向性電磁鋼板を製造するうえで問題であ
った。)を防止し、これにより高Si、高磁束密度を達
成することにより、最近の省エネルギー動向に合致した
低鉄損一方向性電磁鋼板を得ることを可能にした。As described in detail above, the present invention is generated when a continuous cast slab is used as a starting material, which can be manufactured at a low cost and can be industrially manufactured with uniform magnetic properties due to uniform components in the longitudinal direction of the product. It is possible to prevent linear secondary recrystallization defects (especially, when Si is increased to reduce iron loss, it is more likely to occur, which is a problem in producing high-grade grain-oriented electrical steel sheets). By achieving Si and high magnetic flux density, it has become possible to obtain a low iron loss unidirectional electrical steel sheet that matches the recent trend of energy saving.
【0069】[0069]
(実施例1) C:0.07%、Si:3.20%、Mn:0.07
%、S:0.025%、酸可溶性Al:0.025%、
total N:0.0082%、残部:Fe及び不可
避的不純物を含有する250mm厚の連続鋳造スラブを
水冷却条件を制御した引き抜き速度0.50m/min
と、0.90m/min条件で鋳造後、1400℃で加
熱後に、2.3mm厚、2.0mm厚の計4種類の熱延
板とした。(Example 1) C: 0.07%, Si: 3.20%, Mn: 0.07
%, S: 0.025%, acid-soluble Al: 0.025%,
Total N: 0.0082%, balance: Fe and 250% thick continuous cast slab containing unavoidable impurities, withdrawal speed of 0.50 m / min under controlled water cooling conditions.
After casting under the conditions of 0.90 m / min and heating at 1400 ° C., a total of four types of hot-rolled sheets having a thickness of 2.3 mm and 2.0 mm were obtained.
【0070】1120℃で3minの焼鈍後、室温まで
急冷却を行い、2.3mm厚材は0.30mmに、2.
0mm厚材は0.27mmと0.23mmまで冷延し
た。さらに、湿水素雰囲気で850℃で3minの脱炭
焼鈍を行い、MgOを塗布し、1200℃で20hrの
仕上高温焼鈍を行い成品とした。After annealing at 1120 ° C. for 3 minutes, the material was rapidly cooled to room temperature, and the thickness of the 2.3 mm thick material was reduced to 0.30 mm.
The 0 mm thick material was cold rolled to 0.27 mm and 0.23 mm. Further, decarburizing annealing was performed at 850 ° C. for 3 minutes in a wet hydrogen atmosphere, MgO was applied, and finishing high-temperature annealing was performed at 1200 ° C. for 20 hours to obtain a product.
【0071】これら鋳造スラブのS濃厚偏析帯位置と、
成品特性としてのB8と線状二次再結晶不良の発生状況
を表2に示した。The position of the S-rich segregation zone of these cast slabs,
The occurrence of B 8 and the linear secondary recrystallization defect as finished product characteristics are shown in Table 2.
【0072】[0072]
【表2】 [Table 2]
【0073】本発明範囲にある(A)条件では線状二次
再結晶不良の発生もなく良好な磁性が得られた。比較例
の(B)条件では線状二次再結晶不良が発生し、特に成
品厚が薄くなるほど発生大であった。Under the condition (A) within the range of the present invention, good magnetism was obtained without occurrence of linear secondary recrystallization defects. Under the condition (B) of the comparative example, linear secondary recrystallization failure occurred, and the occurrence was particularly large as the product thickness was reduced.
【0074】(実施例2)成分として略、C:0.07
%、Si:3.20%、Mn:0.07%、S:0.0
25%、酸可溶性Al:0.025%、total
N:0.0082%、残部:Fe及び不可避的不純物を
含有する250mm厚の連続鋳造スラブを2種類の連鋳
機で鋳造した。その際の表面の水冷却は比較的に緩やか
にし、引き抜き速度は0.65m/minで行った。(Example 2) As a component, C: 0.07
%, Si: 3.20%, Mn: 0.07%, S: 0.0
25%, acid-soluble Al: 0.025%, total
A continuous casting slab having a thickness of 250 mm containing N: 0.0082%, balance: Fe and inevitable impurities was cast by two types of continuous casting machines. At that time, the surface was cooled with water slowly, and the drawing speed was 0.65 m / min.
【0075】連鋳機は(A)垂直型であり、両表面は同
じ鋳造条件になる。(B)湾曲型であり、曲げ内側は外
側に比べ柱状晶が発生し、バルジング起因のSの濃厚偏
析帯も中心側に寄る。The continuous casting machine is (A) a vertical type, and both surfaces have the same casting conditions. (B) It is a curved type, and columnar crystals are generated on the inside of the bend as compared with the outside, and the dense segregation zone of S due to bulging is also closer to the center side.
【0076】次に、(A)スラブはそのままの(B)ス
ラブについては、(1)曲げ内側面を熱延加熱炉の上面
側、(2)曲げ内側面を熱延加熱炉の下面側、にして加
熱後、2.3mm厚の熱延板とした。Next, for (A) the slab as it is (B), for the slab, (1) the inner side of the bend is the upper side of the hot-rolling furnace, (2) the inner side of the bend is the lower side of the hot-rolling furnace, After heating, a hot-rolled sheet having a thickness of 2.3 mm was obtained.
【0077】さらに、1120℃で3minの焼鈍後、
室温まで急冷却を行い、0.27mm厚まで冷却し、湿
水素雰囲気で850℃で3minの脱炭焼鈍を行い、M
gOを塗布し、1200℃で20hrの仕上高温焼鈍を
行い成品とした。Further, after annealing at 1120 ° C. for 3 minutes,
Cool rapidly to room temperature, cool to 0.27 mm thickness, perform decarburization annealing at 850 ° C. for 3 minutes in a wet hydrogen atmosphere,
gO was applied and subjected to a high-temperature finish annealing at 1200 ° C. for 20 hours to obtain a finished product.
【0078】これら鋳造スラブのS濃厚偏析帯位置と、
成品特性としてのB8と線状二次再結晶不良の発生状況
を表3に示した。The position of the S-rich segregation zone of these cast slabs,
The occurrence of B 8 and the linear secondary recrystallization defect as finished product characteristics are shown in Table 3.
【0079】[0079]
【表3】 [Table 3]
【0080】S濃厚偏析帯が鋳造スラブの両面とも本発
明範囲にある(A)では良好な成品特性であった。一
方、S濃厚偏析帯が片面のみ本発明範囲にある(B)で
は、その面をスラブ加熱炉の上面にした場合、良好な成
品特性を得たが、これに比べてスラブ加熱炉の下面にし
た場合、成品特性は若干悪い。(A), in which the S-rich segregation zone was within the range of the present invention on both sides of the cast slab, had good product properties. On the other hand, in the case of (B) in which only one surface of the S-rich segregation zone is within the range of the present invention, when the surface was set on the upper surface of the slab heating furnace, good product characteristics were obtained. If so, the product characteristics are slightly poor.
【0081】(実施例3)実施例1で用いた鋳造時の引
き抜き速度0.50m/minで板厚2.3mmの熱延
板について、(1)焼鈍なし、(2)950℃×3mi
nを行い、さらに(1)冷延なし、(2)20%圧下冷
延、(3)45%圧下冷延し((1)の場合は、この前
の950℃×3minの焼鈍をしない)、次に1120
℃で3minの焼鈍後、室温まで急冷却を行い、0.2
3mm厚に冷延し、850℃で2minの脱炭焼鈍を行
い、MgOを塗布し、1200℃で20hrの仕上高温
焼鈍を行い成品とした。この成品の磁気特性を表4に示
した。Example 3 The hot-rolled sheet having a thickness of 2.3 mm at a drawing speed of 0.50 m / min used in Example 1 used in Example 1 was (1) no annealing, (2) 950 ° C. × 3 mi.
n) and further (1) no cold rolling, (2) 20% cold rolling, and (3) 45% cold rolling (in the case of (1), do not perform annealing at 950 ° C. × 3 min before). And then 1120
After annealing for 3 min at ℃, quenched to room temperature
The product was cold-rolled to a thickness of 3 mm, decarburized annealing at 850 ° C. for 2 minutes, coated with MgO, and subjected to finishing high-temperature annealing at 1200 ° C. for 20 hours to obtain a product. Table 4 shows the magnetic properties of this product.
【0082】[0082]
【表4】 [Table 4]
【0083】いずれについても、線状二次再結晶不良の
発生はなかった。B8については、1回目冷延を25%
圧下率を行った場合に最も高い値であったが、これは最
終冷延率が最適であったためである。さらに1回目冷延
前に焼鈍を行うことにより、B8は改善されている。In each case, no linear secondary recrystallization failure occurred. For B 8, the first cold-rolled 25%
The highest value was obtained when the rolling reduction was performed, because the final cold rolling reduction was optimal. Further, by performing the annealing in the first cold rolling before, B 8 is improved.
【図1】(a)及び(b)は正常部と線状二次再結晶不
良部の成品マクロ組織を示す写真である。FIGS. 1 (a) and 1 (b) are photographs showing the macrostructures of a normal part and a defective linear secondary recrystallization part.
【図2】(a)及び(b)は一次再結晶組織の結晶粒組
織を示す写真と、板厚方向における集合組織の図表であ
る。FIGS. 2A and 2B are a photograph showing a grain structure of a primary recrystallization structure and a chart of a texture in a plate thickness direction.
【図3】二次再結晶進行過程を示す結晶粒組織の変化の
写真である。FIG. 3 is a photograph of a change in a grain structure showing a progress of secondary recrystallization.
【図4】脱炭焼鈍板の板厚方向での析出物(インヒビタ
ー)の写真である。FIG. 4 is a photograph of a precipitate (inhibitor) in a thickness direction of a decarburized annealed sheet.
【図5】熱延板の板厚方向における集合組織の図表であ
る。FIG. 5 is a chart of a texture in a thickness direction of a hot-rolled sheet.
【図6】(a)は鋳造スラブのマクロ組織、(b)及び
(c)はSの濃度(0.05%以上)分布を示す結晶構
造の写真である。FIG. 6 (a) is a macrostructure of a cast slab, and FIGS. 6 (b) and (c) are crystal structures showing the distribution of S concentration (0.05% or more).
It is a photo of the structure
【図7】線状二次再結晶不良の発生程度に及ぼすS濃厚
偏析帯の成品対応の表面からの位置の影響の図表であ
る。FIG. 7 is a chart showing the influence of the position of the S-rich segregation zone from the surface corresponding to the product on the degree of occurrence of linear secondary recrystallization defects.
Claims (4)
し、鋳片を1320℃以上に加熱し、熱延し、850〜
1150℃の温度域で短時間の焼鈍を行い、圧下率80
%以上の強冷延をし、脱炭焼鈍を行い、仕上高温焼鈍時
の焼き付き防止を目的とした焼鈍分離剤を塗布し、二次
再結晶を主目的とした仕上高温焼鈍を行う一方向性電磁
鋼板の製造方法において、連続鋳造時のバルジング割れ
に起因する0.050%以上のSの濃厚偏析部を少なく
とも鋳片の片側については、製品板厚の表面から53μ
mに対応する位置から内側に制御した連続鋳造片を用い
ることを特徴とする高磁束密度一方向性電磁鋼板の安定
製造方法。1. Si: 3.05 to 4.60%, C: 0.023 to 0.095%, Mn: 0.03 to 0.17%, S: 0.014 to 0.037 by weight %, Acid-soluble Al: 0.018-0.048%, total N: 0.0050-0.0095%, balance: continuous casting of molten steel containing Fe and unavoidable impurities, and heating the slab to 1320 ° C. or more And hot rolled, 850-
Short-time annealing at a temperature range of 1150 ° C and reduction of 80%
% Cold rolling, decarburization annealing, applying an annealing separator to prevent seizure during high temperature annealing, and performing high temperature annealing mainly for secondary recrystallization In the method for manufacturing an electromagnetic steel sheet, the concentrated segregation portion of S of 0.050% or more due to bulging cracks during continuous casting is at least 53 μm from the surface of the product sheet thickness at least on one side of the slab.
A method for stably producing a high magnetic flux density unidirectional magnetic steel sheet, comprising using a continuous cast piece controlled inward from a position corresponding to m.
に際し、バルジング割れに起因するS濃厚偏析部を製品
板厚の表面から53μmに対応する位置から内側に制御
した鋳造側の面を加熱炉の上面側に置くことを特徴とす
る請求項1記載の安定製造方法。2. A method for heating a continuous cast piece prior to hot rolling, in which a surface on the casting side is controlled such that an S-rich segregated portion caused by bulging cracks is controlled inward from a position corresponding to 53 μm from the surface of the product sheet thickness. 2. The stable production method according to claim 1, wherein the method is placed on the upper surface side of the furnace.
延を行い、かつ最終冷延後の製品板厚が0.23mm以
下であることを特徴とする請求項1又は2記載の安定製
造方法。3. The method according to claim 1, wherein before the hot-rolled sheet annealing, cold-rolling is performed at a rolling reduction of 45% or less, and the product sheet thickness after final cold-rolling is 0.23 mm or less. Stable production method.
ことを特徴とする請求項3記載の安定製造方法。4. The stable production method according to claim 3, wherein the hot-rolled sheet is annealed at 850 to 1120 ° C.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4290671A JP2703468B2 (en) | 1992-09-17 | 1992-09-17 | Stable manufacturing method of high magnetic flux density unidirectional electrical steel sheet |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4290671A JP2703468B2 (en) | 1992-09-17 | 1992-09-17 | Stable manufacturing method of high magnetic flux density unidirectional electrical steel sheet |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH06172860A JPH06172860A (en) | 1994-06-21 |
JP2703468B2 true JP2703468B2 (en) | 1998-01-26 |
Family
ID=17758993
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4290671A Expired - Lifetime JP2703468B2 (en) | 1992-09-17 | 1992-09-17 | Stable manufacturing method of high magnetic flux density unidirectional electrical steel sheet |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2703468B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112605122B (en) * | 2020-12-15 | 2023-01-10 | 首钢智新迁安电磁材料有限公司 | Processing method for improving edge quality of silicon steel hot rolled plate |
-
1992
- 1992-09-17 JP JP4290671A patent/JP2703468B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPH06172860A (en) | 1994-06-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP2782086B2 (en) | Manufacturing method of grain-oriented electrical steel sheet with excellent magnetic and film properties | |
JPS6160896B2 (en) | ||
JP2022542380A (en) | Highly magnetically inductive oriented silicon steel and its manufacturing method | |
JPS6250529B2 (en) | ||
JPH03219020A (en) | Production of nonoriented silicon steel sheet | |
JPS6160895B2 (en) | ||
US5330586A (en) | Method of producing grain oriented silicon steel sheet having very excellent magnetic properties | |
EP0475710A2 (en) | Method of manufacturing an oriented silicon steel sheet having improved magnetic characteristics | |
KR100831756B1 (en) | Process for the control of inhibitors distribution in the production of grain oriented electrical steel strips | |
JPH08269571A (en) | Production of grain-oriented silicon steel strip | |
JP2703468B2 (en) | Stable manufacturing method of high magnetic flux density unidirectional electrical steel sheet | |
CN117460851A (en) | Method for producing oriented electrical steel sheet | |
JP3359385B2 (en) | Manufacturing method of unidirectional electrical steel sheet | |
WO2024204818A1 (en) | Method for producing grain-oriented electrical steel sheet, production facility line for grain-oriented electrical steel sheet, and hot rolled sheet for grain-oriented electrical steel sheet | |
JPH06212274A (en) | Production of grain-oriented silicon steel sheet having extremely low iron loss | |
JPH02259016A (en) | Production of grain-oriented silicon steel sheet free from surface blister defect | |
JP2647323B2 (en) | Manufacturing method of grain-oriented electrical steel sheet with low iron loss | |
JP2784661B2 (en) | Manufacturing method of high magnetic flux density thin unidirectional magnetic steel sheet | |
JPH08157963A (en) | Production of grain oriented silicon steel sheet | |
JP2580403B2 (en) | Hot rolling method for continuous cast slab for unidirectional electrical steel sheet. | |
JP3336172B2 (en) | Method for producing unidirectional silicon steel sheet with excellent magnetic properties | |
JPH08269553A (en) | Production of grain-oriented silicon steel sheet excellent in magnetic property | |
JPH02263924A (en) | Production of grain-oriented silicon steel sheet excellent in magnetic property | |
KR970007162B1 (en) | Making method of oriented electrical steel sheet having excellent from loss properties | |
JPH06212262A (en) | Production of grain-oriented silicon steel sheet having extremely low core loss |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 19970902 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20071003 Year of fee payment: 10 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081003 Year of fee payment: 11 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091003 Year of fee payment: 12 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101003 Year of fee payment: 13 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101003 Year of fee payment: 13 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111003 Year of fee payment: 14 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111003 Year of fee payment: 14 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121003 Year of fee payment: 15 |
|
EXPY | Cancellation because of completion of term |