JPH0730395B2 - Manufacturing method of grain-oriented electrical steel sheet without surface bulge defect - Google Patents
Manufacturing method of grain-oriented electrical steel sheet without surface bulge defectInfo
- Publication number
- JPH0730395B2 JPH0730395B2 JP1082233A JP8223389A JPH0730395B2 JP H0730395 B2 JPH0730395 B2 JP H0730395B2 JP 1082233 A JP1082233 A JP 1082233A JP 8223389 A JP8223389 A JP 8223389A JP H0730395 B2 JPH0730395 B2 JP H0730395B2
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- Prior art keywords
- annealing
- steel sheet
- slab
- hot
- electrical steel
- Prior art date
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Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は表面脹れ欠陥の無い一方向性電磁鋼板を工業的
に安定してかつ安価に製造する方法に関するものであ
る。Description: TECHNICAL FIELD The present invention relates to a method for industrially producing a grain-oriented electrical steel sheet having no surface bulging defects that is stable and inexpensive.
（従来の技術） 一方向性電磁鋼板は鋼板面が｛110｝面で、圧延方向が
〈100〉軸を有するいわゆるゴス方位〔ミラー指数で｛1
10｝〈001〉方位と表す〕を持つ結晶粒から構成されて
おり、軟磁性材料として変圧器、および発電機用の鉄心
に使用される。(Prior Art) A unidirectional electrical steel sheet has a so-called Goss orientation having a {110} plane in the steel sheet plane and a <100> axis in the rolling direction [Mirror index {1
It is composed of crystal grains having a 10} <001> orientation] and is used as a soft magnetic material for transformers and iron cores for generators.
この鋼板は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
の磁場力で鉄心内に誘起される磁束密度の大小で決ま
り、その磁束密度の大きさは鋼板結晶粒の方位を｛11
0｝〈001〉に高度に揃えることによって達成出来る。鉄
損は鉄心に所定の交流磁場を与えた場合に熱エネルギー
として消費される電力損失であり、その良否に対し磁束
密度，板厚，不純物量，比抵抗，結晶粒の大きさ等、が
影響する。特に、磁束密度の大きい鋼板は電気機器を小
さく出来、また鉄損も少なくなるので望ましい。This steel sheet must have good magnetic properties and iron loss properties. The quality of the magnetization characteristics is determined by the magnitude of the magnetic flux density induced in the iron core by the applied constant magnetic field force.
This can be achieved by aligning with 0} <001>. Iron loss is the power loss consumed as thermal energy when a given AC magnetic field is applied to the iron core, and the magnetic flux density, plate thickness, amount of impurities, specific resistance, size of crystal grains, etc. affect its quality. To do. In particular, a steel sheet with a high magnetic flux density is desirable because it can make electrical equipment small and reduce iron loss.
ところで一方向性電磁鋼板は熱間圧延と冷間圧延と焼鈍
との適切な組合せ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、｛110｝〈001〉方位を有する一
次再結晶粒が選択成長するいわゆる二次再結晶によって
得られる。二次再結晶は二次再結晶前の鋼板中に微細な
析出物、例えばMnS,AlN,MnSe等、が存在すること、ある
いはSn,Sb,P,等の粒界存在型の元素が存在することによ
って達成される。これら析出物及び粒界存在型の元素は
メイ アンド ターンブル（J.E May and D.Turnbull）
（トランスアクションズ・メタラジカル・ソサイエティ
・エーアイエムイー Trans.Met.Soc.AIME212（1958）p
769/781）によって説明されているように、仕上高温焼
鈍中の｛110｝〈001〉方位以外の一次再結晶粒の成長を
抑え、｛110｝〈001〉方位粒を選択的に成長させる機能
を持つ。このような粒成長の抑制作用を、一般的にはイ
ンヒビター効果と呼んでいる。したがって当該分野の研
究開発の重点課題は、如何なる種類の析出物あるいは粒
界存在型の元素を用いて二次再結晶を安定させるか、そ
して正確な｛110｝〈001〉方位粒の存在割合を高めるた
めにそれらの適切な存在状態をいかに達成するかにあ
る。析出物の種類として、エム・エフ・リットマン（M.
F.Littmann）は特公昭30-3651号公報に、メイ アンド
ターンブルはトランスアクションズ・メタラジカル・
ソサイエティ・エーアイエムイー212（1958）p769/781
にMnSを、田中、板倉は特公昭33-4710号公報にAlNを、
フィードラーはトランスアクションズ・メタラジカル・
ソサイエティ・エーアイエムイー221（1961）p1201/120
5にVNを、今中らは特公昭51-13469号公報にMnSeを、フ
ァストはフィリップ リサーチレポート（1956）11.p49
0にSi3N4を述べており、その他TiS,CrS,CrC,NbC,SiO2等
も公表されている。又、粒界存在型の元素として、日本
金属学会誌27（1963）p186、（斉藤達雄）にAs,Sn,Sb等
が述べられているが、工業生産においては、これら元素
単独で使用される例は無く、いずれも析出物と共存させ
て、その補助的効果を狙って使用される。したがって、
一方向性電磁鋼板の製造に当って、いかなる種類の析出
物を利用するかが、高度に｛110｝〈001〉方位に揃え、
かつ工業的に安定生産を可能にすることの鍵となる。By the way, a unidirectional electrical steel sheet is a primary recrystallized grain having a {110} <001> orientation obtained by finishing high temperature annealing of a steel sheet having a final thickness obtained by an appropriate combination of hot rolling, cold rolling and annealing. Are obtained by so-called secondary recrystallization in which selective growth is performed. Secondary recrystallization is the presence of fine precipitates in the steel sheet before secondary recrystallization, for example, MnS, AlN, MnSe, or the presence of grain boundary type elements such as Sn, Sb, P, etc. To be achieved. These precipitates and grain boundary type elements are JE May and D. Turnbull
(Transactions Meta Radical Society AIM Trans.Met.Soc.AIME212 (1958) p
769/781), the function to suppress the growth of primary recrystallized grains other than the {110} <001> orientation during the finishing high temperature annealing and selectively grow the {110} <001> orientation grains. have. Such an effect of suppressing grain growth is generally called an inhibitor effect. Therefore, the focus of research and development in this field is to determine what kind of precipitate or grain boundary existence type element is used to stabilize the secondary recrystallization, and to determine the exact proportion of {110} <001> oriented grains. It is how to achieve their proper presence to enhance. As a kind of deposit, M. F. Littmann (M.
F. Littmann) in Japanese Examined Patent Publication No. 30-3651, and May and Turnbull in Transactions Metaradical.
Society AIM 212 (1958) p769 / 781
MnS, Tanaka and Itakura AlN in Japanese Patent Publication No. 33-4710.
Fiedler is Transactions Metaradical
Society AIM221 (1961) p1201 / 120
5, VN, Konaka et al., MnSe in JP-B-51-13469, and Fast in Philip Research Report (1956) 11.p49.
0 describes Si 3 N 4 , and other TiS, CrS, CrC, NbC, SiO 2, etc. are also announced. As elements of grain boundary existence type, As, Sn, Sb, etc. are described in Journal of Japan Institute of Metals 27 (1963) p186, (Tatsuo Saito), but these elements are used alone in industrial production. There is no example, and both are used with the purpose of co-existing with the precipitate and its auxiliary effect. Therefore,
In the production of unidirectional electrical steel sheet, what kind of precipitate is used is highly aligned in the {110} <001> direction.
And it is the key to enabling industrially stable production.
上記要約からも明らかなように高磁束密度（｛110｝〈0
01〉方位の高集積度）を得るためには、析出物を微細で
均一、かつ多量に仕上高温焼鈍前の鋼板中に存在させる
ことが必要である。このために、今までにも多くの技術
が開示され、その中で素材成分、および熱処理条件が制
御されて来た。さらに、高磁束密度材を得るためには、
析出物の制御と同時に、その析出物の特性に合致すべく
圧延、熱処理の適切な組合せにより二次再結晶前の一次
再結晶組織の性状を制御することが重要である。As is clear from the above summary, high magnetic flux density ({110} 〈0
In order to obtain a high degree of 01> orientation accumulation, it is necessary that fine precipitates are present in the steel sheet before finishing high temperature annealing in a fine, uniform and large amount. For this reason, many techniques have been disclosed so far, and the material components and heat treatment conditions have been controlled therein. Furthermore, in order to obtain a high magnetic flux density material,
At the same time as controlling the precipitate, it is important to control the properties of the primary recrystallization structure before secondary recrystallization by an appropriate combination of rolling and heat treatment so as to match the characteristics of the precipitate.
（発明が解決しようとする課題） 現在、工業生産されている代表的な一方向性電磁鋼板製
造法として３種類ある。(Problems to be Solved by the Invention) Currently, there are three types of typical unidirectional electrical steel sheet production methods that are industrially produced.
第１の技術はエム・エフ・リットマンによる特公昭30-3
651号公報に示された。MnSを用いた二回冷延工程であ
り、第２の技術は田口、板倉による特公昭40-15644号公
報に示されたAlN＋MnSを用いた最終冷延工程を80％以上
の強冷延率とする工程であり、第３の技術は今中等によ
る特公昭51-13469号公報に示されたMnS（または、およ
びMnSe）＋Sbを用いた二回冷延工程である。上記技術は
いずれもが、析出物を微細、均一に制御する手段として
熱間圧延に先立つスラブ加熱温度を第１の技術では1260
℃以上、第２の技術では特開昭48-51852号公報に示すよ
うに素材Si量によるが３％Siの場合で1350℃、第３の技
術では特開昭51-20716号公報に示されるように1230℃以
上、高磁束密度の得られる実施例では1320℃といった極
めて高い温度にすることによって粗大に存在する析出物
を一旦固溶し、その後の熱間圧延中、あるいは熱延板焼
鈍処理中に微細に析出させている。スラブ加熱温度を上
げることはスラブ加熱時の使用エネルギーの増大、ノロ
の発生による歩留低下および補修費の増大、さらには特
公昭57-41526号公報に示されるように二次再結晶不良が
発生するために連続鋳造スラブが使用出来ない、等低コ
スト製造工程を実現する上で解決すべき本質的な課題を
抱えている。最近、特公昭62-45285号公報は１回冷延法
をベースに最終冷延後の窒化処理で、（Al,Si）Ｎ析出
物を形成させ、これを二次再結晶に対するインヒビター
として機能させることにより、高温スラブ加熱を不用と
する技術を開示した。これは、低コスト製造プロセスへ
の新しい展開をもたらすものである。この技術をベース
に、更に低コストにするための一つの方法は、特公昭62
-45285号公報に開示されているように、熱延板焼鈍工程
を省略することである。しかしながら、この熱延板焼鈍
工程を省略し、熱延板を直接に冷延すると磁束密度が劣
化することは勿論、最終成品に表面脹れ欠陥が発生し、
製品にならないという致命的問題が生じる。The first technique is M. F. Littmann's Japanese Patent Publication Sho 30-3
No. 651 publication. It is a double cold rolling process using MnS. The second technology is the final cold rolling process using AlN + MnS disclosed in Japanese Patent Publication No. 40-15644 by Taguchi and Itakura with a strong cold rolling rate of 80% or more. The third technique is a double cold rolling process using MnS (or MnSe) + Sb disclosed in Japanese Patent Publication No. 51-13469. In all of the above techniques, the slab heating temperature prior to hot rolling is set to 1260 in the first technique as a means for finely and uniformly controlling precipitates.
℃ or higher, as shown in Japanese Patent Laid-Open No. 48-51852, it depends on the amount of Si in the material, but it is 1350 ° C. when 3% Si, and in the third technique, Japanese Patent Laid-Open No. 51-20716. As described above, the precipitates that are coarsely present are once solid-dissolved by raising the temperature to an extremely high temperature of 1230 ° C. or higher, or 1320 ° C. in the example in which a high magnetic flux density is obtained, and then during hot rolling or hot rolled sheet annealing treatment. Finely deposited inside. Increasing the slab heating temperature increases the energy used during slab heating, lowers the yield due to the generation of slag, and increases repair costs, as well as secondary recrystallization defects as shown in Japanese Patent Publication No. 57-41526. Therefore, there is an essential problem to be solved in order to realize a low cost manufacturing process such as the continuous casting slab cannot be used. Recently, Japanese Examined Patent Publication No. 62-45285 discloses a nitriding treatment after final cold rolling based on a single cold rolling method to form an (Al, Si) N precipitate, which serves as an inhibitor for secondary recrystallization. In this way, a technique that does not require high temperature slab heating has been disclosed. This brings new developments to low cost manufacturing processes. Based on this technology, one way to reduce the cost is
No. 45285, the hot-rolled sheet annealing step is omitted. However, if this hot-rolled sheet annealing step is omitted and the hot-rolled sheet is directly cold-rolled, the magnetic flux density is deteriorated, and surface swelling defects occur in the final product,
The fatal problem of not becoming a product occurs.
本発明は、窒化処理によって形成させた（Al,Si）Ｎを
利用する一回冷延工程において、熱延板焼鈍工程を省略
し、直接に冷延した場合に発生する最終成品の表面脹れ
欠陥を解消し、さらに磁束密度劣化の改善をしようとす
るものである。INDUSTRIAL APPLICABILITY According to the present invention, in the single cold rolling process using (Al, Si) N formed by the nitriding treatment, the hot rolling sheet annealing process is omitted, and the surface expansion of the final product occurs when directly cold rolling. It is intended to eliminate defects and further improve deterioration of magnetic flux density.
（課題を解決するための手段） 本発明者等は最終成品の表面脹れ欠陥の発生原因、さら
に、磁束密度の劣化の主な原因が線状二次再結晶不良の
発生によることを明らかにし、この両者は冷間圧延ロー
ル直径を一定以上の大きさにすることによって解消する
ことを見い出した。冷間圧延ロール直径と表面脹れ欠陥
そして線状二次再結晶不良との関係を以下に説明する。(Means for Solving the Problem) The present inventors have clarified that the cause of the surface bulge defect of the final product and the main cause of the deterioration of the magnetic flux density are the occurrence of linear secondary recrystallization defects. It has been found that both of them are solved by increasing the diameter of the cold rolling roll to a certain size or more. The relationship between the diameter of the cold rolling roll, the surface swelling defect, and the linear secondary recrystallization defect will be described below.
重量比でC:0.045％,Si:3.30％,Mn:0.14％,P:0.022％,S:
0.007％，酸可溶性Al:0.031％,T.N:0.0078％，残部:Fe
および不可避的不純物から成る連続鋳造スラブを1150℃
に加熱後、2.3mmの熱延板とし、酸洗し、0.30mmまで冷
間圧延し、850℃×120sec間、湿水素中で脱炭焼鈍し、M
gO＋３％TiO2＋７％窒化フェロマンガンを塗布し、乾燥
し、1200℃×20hrの仕上高温焼鈍を行った。この時の冷
間圧延時のロール直径を60mm,100mm,150mm,270mm,490mm
として、それぞれのロールを用いて冷間圧延した時の成
品の表面脹れ欠陥と、線状二次再結晶不良との発生程度
を第１図に示した。第１図から分かるように、冷間圧延
ロール直径が150mm以上では、表面脹れ欠陥と線状二次
再結晶不良のいずれもが解消する。C: 0.045%, Si: 3.30%, Mn: 0.14%, P: 0.022%, S:
0.007%, acid soluble Al: 0.031%, TN: 0.0078%, balance: Fe
And continuous slabs consisting of inevitable impurities at 1150 ℃
After heating to 2.3 mm, it is hot rolled to 2.3 mm, pickled, cold-rolled to 0.30 mm, decarburized and annealed in wet hydrogen for 850 ° C × 120 sec.
gO + 3% TiO 2 + 7% ferromanganese nitride was applied, dried, and subjected to finish high-temperature annealing at 1200 ° C. × 20 hr. Roll diameter during cold rolling at this time is 60 mm, 100 mm, 150 mm, 270 mm, 490 mm
As a result, FIG. 1 shows the degree of occurrence of surface swelling defects and linear secondary recrystallization defects in the product when cold rolled using each roll. As can be seen from FIG. 1, when the diameter of the cold rolling roll is 150 mm or more, both the surface swelling defect and the linear secondary recrystallization defect are eliminated.
本発明者等は次にこれら欠陥発生原因を解明するために
工程処理途中の鋼板金属組織を調査した。The present inventors next investigated the steel sheet metal structure during the process treatment in order to elucidate the cause of these defects.
第２図はロール直径100mmの場合の成品の鋼板表面マク
ロ組織である。図中央の円で囲んだ部分が表面脹れ欠陥
であり、さらにその圧延方向延長部分に並んで線状二次
再結晶不良も発生している。この表面脹れ部の延長上
（第２図の矢印部）に隣接した冷延板、脱炭焼鈍板の圧
延方向と直角断面の顕微鏡組織をそれぞれ第３図
（Ａ），（Ｂ）に示す。冷延板の板厚中心近傍に黒く見
えるのは微少な割れであり、この部分が脱炭焼鈍板では
若干大きくなっている。このような割れ部が著しい場合
に最終成品では表面脹れとなり、その軽度の場合に線状
二次再結晶不良の原因になるものと思われる。なお、第
１図に示した表面脹れ欠陥、線状二次再結晶不良の発生
は、冷延前に1120℃×2minの熱延板焼鈍を行なうことに
より、ロール直径の大きさに拘らず、全く無い。Fig. 2 shows the steel sheet surface macrostructure of the product when the roll diameter is 100 mm. The portion surrounded by a circle in the center of the figure is a surface swelling defect, and linear secondary recrystallization defects also occur alongside the extended portion in the rolling direction. The microstructures of the cold-rolled sheet and the decarburized and annealed sheet adjacent to the extension of the surface bulge (the arrow in FIG. 2) are shown in FIGS. 3 (A) and 3 (B), respectively. . It is a slight crack that appears black near the center of the thickness of the cold rolled sheet, and this portion is slightly larger in the decarburized annealed sheet. It is considered that when such cracks are remarkable, surface swelling occurs in the final product, and when the cracks are slight, they cause defective linear secondary recrystallization. The occurrence of surface swelling defects and linear secondary recrystallization defects shown in Fig. 1 was irrespective of the roll diameter by performing hot-rolled sheet annealing at 1120 ° C for 2 min before cold rolling. , Not at all.
このように、本発明は、スラブ加熱温度の低い熱延板を
素材として、熱延板焼鈍なしで直接に強冷延する一方向
性電磁鋼板製造工程において、最終成品に表面脹れ欠陥
及び線状二次再結晶不良が発生することを初めて知見
し、その原因究明と解決手段を開示するものである。As described above, the present invention is a unidirectional electrical steel sheet manufacturing process in which a hot rolled sheet having a low slab heating temperature is used as a raw material and directly subjected to strong cold rolling without annealing the hot rolled sheet. It is the first time to discover that a secondary recrystallization defect occurs, and to investigate the cause and to disclose a solution.
以下、本発明の構成要件の限定理由を実施態様に基づい
て説明する。Hereinafter, the reasons for limiting the constituent features of the present invention will be described based on the embodiments.
本発明で用いる溶鋼は転炉、電気炉等その溶製方法を問
わないが、成分として次の含有量範囲にある必要があ
る。The molten steel used in the present invention may be produced by a converter, an electric furnace, or the like, regardless of its melting method, but it is necessary that the content of the molten steel be within the following range.
Siは1.5％未満では仕上高温焼鈍時にα→γ変態がある
ため、結晶方位が破壊されるので、1.5％以上とした。S
i量は多くなると鉄損は減少して望ましいが、磁束密度
はむしろ減少する。約6.65％前後で最高鉄損となり、そ
れ以上増やしてもむしろ磁束密度が劣化するので上限を
6.7％迄とした。Si量が増加すると脆性が著しく、4.5％
前後以上で特に冷延割れは増加するが、圧延時の鋼板温
度を衝撃試験の遷移温度、例えば6.5％で280℃前後、以
上で行なえば、基本的には可能である。If the Si content is less than 1.5%, the crystal orientation is destroyed due to the α → γ transformation during finish high temperature annealing, so the content was made 1.5% or more. S
As the amount of i increases, the iron loss decreases, which is desirable, but the magnetic flux density decreases rather. The maximum iron loss is around 6.65%, and even if the iron loss is increased beyond that, the magnetic flux density deteriorates.
Up to 6.7%. As the Si content increases, brittleness becomes remarkable, 4.5%
Although cold-rolling cracks increase especially before and after, it is basically possible if the steel sheet temperature during rolling is about 280 ° C at the transition temperature of impact test, for example, 6.5%.
本発明では二次再結晶に必要な析出分散相として（Al,S
i）Ｎを主に用い、必要に応じてAlNを補助とする。従っ
て、必要析出分散相量を確保するために酸可溶性Alとし
て0.012％以上を含有させる。酸可溶性Alが0.040％を超
えると二次再結晶の発現が不安定になる。In the present invention, (Al, S
i) N is mainly used, and AlN is supplemented as needed. Therefore, 0.012% or more is contained as the acid-soluble Al in order to secure the required amount of precipitated dispersed phase. When the acid-soluble Al content exceeds 0.040%, the onset of secondary recrystallization becomes unstable.
Ｔ（total）.Nについては、0.0095％を超えると鋼板表
面にブリスターと呼ばれる脹れ状の欠陥が発生するので
0.0095％以下とした。T.Nの下限については、その量が
少ない場合には途中工程処理条件、例えば窒化量、を調
節する事で対処可能であるので、特に限定しない。しか
し、通常の溶製法で特別な処理を付加しない場合、不純
物として0.0025％程度含有される。As for T (total) .N, if it exceeds 0.0095%, blistering defects called blister will occur on the steel plate surface.
It was set to 0.0095% or less. The lower limit of TN is not particularly limited, because when the amount is small, it can be dealt with by adjusting the treatment condition in the intermediate process, for example, the nitriding amount. However, if no special treatment is added by the usual melting method, it is contained as an impurity in an amount of about 0.0025%.
Ｓについては、本発明がインヒビターとしてMnSの利用
を考えていないので、特に限定する必要は無く、むしろ
MnSが存在すると、後工程での窒化処理による（Al,Si）
Ｎの析出核となり、粗大になるので影響を有効に活かす
ためには、低い方が望ましい。特にスラブ加熱温度の高
い場合に、MnSが全体に密に存在することになるので、
（Al,Si）Ｎの析出制御が困難になり望ましくない。Ｓ
が0.014％以下になると、MnSとしての影響は小さくな
り、B8（θ/m）が1.88Tesla以上になり望ましい。Regarding S, since the present invention does not consider the use of MnS as an inhibitor, there is no particular need to limit it, but rather
If MnS is present, it will be treated by nitriding in the later process (Al, Si)
Since it becomes N precipitation nuclei and becomes coarse, the lower one is preferable in order to effectively utilize the effect. Especially when the slab heating temperature is high, MnS will be densely present in the whole, so
It is not desirable because it becomes difficult to control the precipitation of (Al, Si) N. S
Is 0.014% or less, the effect as MnS is small, and B 8 (θ / m) is 1.88 Tesla or more, which is desirable.
なお、Ｃについては0.025％以上でより高磁束密度とな
るが、それ未満で行なっても充分に二次再結晶する。む
しろ、Ｃが0.025％未満になると、表面脹れ欠陥が著る
しくなり、本発明で採用する冷間圧延条件でないと、ほ
とんど製品とならず、本発明の効果は顕著である。It should be noted that when C is 0.025% or more, the magnetic flux density becomes higher, but even if it is less than that, secondary recrystallization is sufficiently performed. On the contrary, when C is less than 0.025%, the surface swelling defect becomes remarkable, and almost no product is obtained unless the cold rolling conditions adopted in the present invention are used, and the effect of the present invention is remarkable.
上記限定成分以外は残部Feおよび不可避的不純物である
が、本発明の主旨を変えない条件であれば、他目的での
元素添加は差支えない。Other than the above-mentioned limited components, the balance is Fe and inevitable impurities, but addition of elements for other purposes may be made under the conditions that do not change the gist of the present invention.
次に、このような成分範囲にある珪素鋼スラブを熱延板
とする。Next, a silicon steel slab having such a composition range is used as a hot rolled sheet.
本発明は、後工程で窒化処理により形成させた（Al,S
i）Ｎを二次再結晶に対するインヒビターとして利用す
る技術を基盤とするので、AlとＮとを完全には溶体化し
ない温度域にスラブ加熱することを必須とする。特に、
本発明は、今迄にない低コストでの製造を目的としてい
る事から、スラブ加熱時にノロ発生の全く無い1280℃未
満が望ましい。このような低温スラブ加熱による本発明
は、当然次のような方法で熱延板を作ることも可能であ
る。最近の連続鋳造技術の進歩により連続鋳造の生産性
が連続熱延機の能力に匹敵するほど大きくなったため、
連続鋳造機と連続熱延機と直結して材料を流しても、熱
延機の材料待ち時間が無くなった。そこで、連続鋳造後
にスラブを冷却することなく、スラブ顕熱を利用して直
接に熱延する方法、あるいはスラブ温度特に表面温度が
若干下がった場合には復熱炉に装入した後に熱延する方
法を容易に採用出来る。このようにして得られた熱延板
は、熱延板焼鈍なしに、酸洗等により表面スケール除去
後に、直接最終製品厚に冷間圧延される。冷延率が80％
以上で高磁束密度となるが、本発明では特に限定しな
い。この時の冷間圧延ロール直径が150mm以上で、完全
に表面脹れ欠陥が解消する。すなわち、鋼中Ｃ量が低い
場合、熱延時のスラブ加熱温度が低い場合、に特に表面
脹れ欠陥が著しいが、このような場合でも150mm以上の
ロール直径であれば問題無い。このロール直径の効果は
冷間圧延の初期に大きく、例えば冷間圧延率でほぼ35％
を超えた圧下範囲では冷間圧延ロール直径が大きくて
も、小さくても表面脹れ欠陥発生程度に殆んど差がなく
なる。The present invention is formed by a nitriding treatment in the subsequent process (Al, S
i) Since the technology is based on the use of N as an inhibitor for secondary recrystallization, it is essential to perform slab heating to a temperature range where Al and N are not completely dissolved. In particular,
Since the present invention is aimed at manufacturing at a low cost which has never been achieved, it is desirable that the temperature is less than 1280 ° C. at which no slag is generated when the slab is heated. In the present invention by such low temperature slab heating, it is of course possible to produce a hot rolled sheet by the following method. Due to the recent advances in continuous casting technology, the productivity of continuous casting has increased to a level comparable to that of continuous hot rolling machines.
Even if the continuous casting machine and the continuous hot rolling machine were directly connected to flow the material, the material waiting time of the hot rolling machine was eliminated. Therefore, without continuously cooling the slab after continuous casting, a method of directly performing hot rolling using slab sensible heat, or when the slab temperature, in particular the surface temperature, drops slightly after being placed in a reheat furnace The method can be easily adopted. The hot-rolled sheet thus obtained is directly cold-rolled to the final product thickness after the surface scale is removed by pickling without annealing the hot-rolled sheet. Cold rolling rate is 80%
Although a high magnetic flux density is obtained as above, the present invention is not particularly limited. At this time, when the diameter of the cold rolling roll is 150 mm or more, the surface expansion defect is completely eliminated. That is, when the C content in the steel is low and the slab heating temperature during hot rolling is low, the surface swelling defect is particularly remarkable, but even in such a case, there is no problem if the roll diameter is 150 mm or more. The effect of this roll diameter is large at the initial stage of cold rolling, for example, the cold rolling rate is approximately 35%.
In the rolling reduction range exceeding 0.15 mm, there is almost no difference in the degree of surface swelling defect generation even if the diameter of the cold rolling roll is large or small.
かくして得られた冷延板は次いで脱炭焼鈍される。脱炭
焼鈍工程は一次再結晶及び脱炭を行わせると同時に、成
品表面のフォルステライト系絶縁皮膜の形成に必要なSi
O2を含む酸化膜を生成させる役割を持っている。The cold-rolled sheet thus obtained is then decarburized and annealed. In the decarburization annealing process, the primary recrystallization and decarburization are performed, and at the same time, the Si required for forming the forsterite type insulation film on the surface of the product is
It has a role of forming an oxide film containing O 2 .
脱炭焼鈍後の鋼板表面には仕上高温焼鈍時における焼付
防止、及びフォルステライト系絶縁皮膜形成のためにMg
Oを主成分とする焼鈍分離剤を塗布・乾燥する。引き続
いて、仕上高温焼鈍を行なう。この工程は二次再結晶、
フォルステライト系皮膜形成および純化を目的としてお
り、通常1100℃以上、5hr以上水素又は水素を含んだ混
合雰囲気中で行なう。After decarburization annealing, the surface of the steel sheet is coated with Mg to prevent seizure during finishing high temperature annealing and to form a forsterite type insulation film.
Apply an annealing separator containing O as a main component and dry. Subsequently, high temperature finishing annealing is performed. This process is a secondary recrystallization,
For the purpose of forming and purifying a forsterite film, it is usually performed at 1100 ° C or higher for 5 hours or longer in hydrogen or a mixed atmosphere containing hydrogen.
本発明は以上の構成に加え、脱炭焼鈍から仕上高温焼鈍
の二次再結晶開始前迄のいずれかの過程で窒化処理する
事を必須条件とする。すなわち、本発明では、二次再結
晶配向度制御に必要な析出分散相は冷間圧延後の窒化処
理により形成されるものであり、この方法によって、始
めて熱延板焼鈍なしでも高磁束密度一方向性電磁鋼板の
製造が可能になる。これに対し、高温スラブ加熱をベー
スとする従来の技術では、この熱延板焼鈍によりAlN析
出物制御を必須とするので、本発明の目的である熱延板
焼鈍の省略は不可能である。In addition to the above-mentioned constitution, the present invention requires that the nitriding treatment is performed in any process from the decarburization annealing to the start of secondary recrystallization of finishing high temperature annealing. That is, in the present invention, the precipitation-dispersed phase required for the secondary recrystallization orientation degree control is formed by the nitriding treatment after cold rolling, and by this method, the high magnetic flux density 1 It enables the production of grain-oriented electrical steel sheets. On the other hand, in the conventional technique based on high-temperature slab heating, the control of AlN precipitates is indispensable by this hot-rolled sheet annealing, and thus it is impossible to omit the hot-rolled sheet annealing which is the object of the present invention.
窒化処理は、冷延後の脱炭焼鈍雰囲気に窒化能のあるア
ンモニアを添加する、脱炭焼鈍完了後に窒化雰囲気で追
加焼鈍する、焼鈍分離剤中に窒化能のある化合物、例え
ば窒化フェロマンガン，窒化フェロクロムを添加する、
さらには仕上高温焼鈍の二次再結晶発現までの加熱中に
窒化を促進する雰囲気条件とする、等いずれも有効であ
る。The nitriding treatment includes adding ammonia having a nitriding ability to the decarburizing annealing atmosphere after cold rolling, additionally annealing in the nitriding atmosphere after completion of the decarburizing annealing, a compound having a nitriding ability in the annealing separator, for example, ferromanganese nitride. Add ferrochrome nitride,
Furthermore, it is effective to use an atmosphere condition that promotes nitriding during the heating until the secondary recrystallization in the high-temperature annealing for finishing.
（実施例） （実施例１） C:0.043％,Si:3.27％,Mn:0.13％.P:0.012％,S:0.007
％，酸可溶性Al:0.029％,T.N:0.0082％，残部:Feおよび
不可避的不純物から成る連続鋳造スラブを1150℃と1350
℃にそれぞれ加熱後、2.3mmの熱延板とし、酸洗し、ロ
ール直径100mmと150mmの冷間圧延ロールで0.30mmに冷間
圧延し、850℃×120secにて、湿水素中で脱炭焼鈍し、M
gO＋３％TiO2＋７％窒化フェロマンガンを塗布し、乾燥
し、1200℃×20hrの仕上高温焼鈍を行なった。この成品
の表面脹れ欠陥と線状二次再結晶不良の発生程度と磁束
密度を第１表に示す。(Example) (Example 1) C: 0.043%, Si: 3.27%, Mn: 0.13% .P: 0.012%, S: 0.007
%, Acid-soluble Al: 0.029%, TN: 0.0082%, balance: Fe and unavoidable impurities at 1150 ℃ and 1350 ℃
After heating to ℃ each, to make a hot rolled 2.3mm plate, pickled, cold rolled to 0.30mm by cold rolling rolls with roll diameters of 100mm and 150mm, and decarburized in wet hydrogen at 850 ℃ × 120sec. Annealed, M
gO + 3% TiO 2 + 7% ferromanganese nitride was applied, dried, and subjected to finish high-temperature annealing at 1200 ° C. × 20 hr. Table 1 shows the degree of occurrence of surface bulging defects, linear secondary recrystallization defects, and magnetic flux density of this product.
第１表から分かるように、スラブ加熱温度が高い場合に
表面脹れ欠陥は発生し難く、低い場合は発生し始める
が、冷間圧延ロール直径が150mmでは発生しない。又、
磁性はスラブ加熱温度が低く、ロール直径150mmの場合
が優れている。 As can be seen from Table 1, when the slab heating temperature is high, surface swelling defects are less likely to occur, and when the slab heating temperature is low, they begin to occur, but they do not occur when the cold rolling roll diameter is 150 mm. or,
Magnetism is excellent when the slab heating temperature is low and the roll diameter is 150 mm.
（実施例２） 実施例１のスラブ加熱温度1150℃の熱延板について、酸
洗し、 （Ａ）ロール直径150mmで15％だけ冷間圧延後、ロール
直径60mmで0.30mmまで冷間圧延 （Ｂ）ロール直径150mmで40％だけ冷間圧延後、ロール
直径60mmで0.30mmまで冷間圧延 （Ｃ）ロール直径60mmで0.30mmまで冷間圧延、 の３種類の冷間圧延後、850℃×120secにて、湿水素中
で脱炭焼鈍し、MgO＋３％TiO2＋７％窒化フェロマンガ
ンを塗布し、乾燥し、1200℃×20hrの仕上高温焼鈍を行
なった。この成品の表面脹れ欠陥の発生程度と磁束密度
を第２表に示す 第２表から分かるように、（Ｂ）条件のように直径の大
きいロールで40％の冷間圧延後に小径ロールで最終板厚
まで仕上げた成品は表面脹れ欠陥も無く、磁性も良好で
あるが、（Ａ）条件のように大径ロールでの冷間圧延が
15％で、その後小径ロールで最終板厚まで仕上げた成
品、又（Ｃ）条件のように最初から最後まで小径ロール
で冷間圧延したものは表面脹れ欠陥が発生し、磁束密度
も悪い。(Example 2) The hot-rolled sheet having a slab heating temperature of 1150 ° C of Example 1 was pickled, and (A) cold-rolled at a roll diameter of 150 mm by 15%, and then cold-rolled at a roll diameter of 60 mm to 0.30 mm ( B) Cold rolling with roll diameter 150 mm by 40%, then cold rolling with roll diameter 60 mm to 0.30 mm (C) Cold rolling with roll diameter 60 mm to 0.30 mm, 850 ℃ × At 120 seconds, decarburization annealing was performed in wet hydrogen, MgO + 3% TiO 2 + 7% ferromanganese nitride was applied, dried, and subjected to finishing high temperature annealing at 1200 ° C. × 20 hr. Table 2 shows the degree of occurrence of surface swelling defects and the magnetic flux density of this product. As can be seen from Table 2, the product obtained by cold rolling 40% with a roll having a large diameter and finishing with a roll having a small diameter to the final plate thickness as in the condition (B) has no surface bulging defect and has good magnetism. However, cold rolling with large-diameter rolls like the condition (A)
A product having a diameter of 15% and finished with a small-diameter roll to the final plate thickness or cold-rolled with a small-diameter roll from the beginning to the end as in the condition (C) has surface swelling defects and poor magnetic flux density.
（実施例３） C:0.046％,Si:3.32％,Mn:0.12％,P:0.022％，酸可溶性A
l:0.029％,T.N:0.0082％，残部Feおよび不可避的不純物
を含み、さらにＳをそれぞれ0.013％と0.021％とを含む
２種類の連続鋳造スラブを鋳造後、表面温度1040℃の段
階で熱延し、2.3mmの熱延板とし、酸洗し、ロール直径2
70mmで0.30mmまで冷間圧延し、830℃×120secにて湿水
素中で脱炭焼鈍し、アンモニア含有水素雰囲気中で窒化
焼鈍をし、MgO＋３％TiO2を塗布し、乾燥し、1200℃×2
0hrの仕上高温焼鈍を行なった。この成品の表面脹れ欠
陥の発生程度と磁束密度を第３表に示す。(Example 3) C: 0.046%, Si: 3.32%, Mn: 0.12%, P: 0.022%, acid-soluble A
l: 0.029%, TN: 0.0082%, balance Fe and unavoidable impurities, and two types of continuous casting slabs containing 0.013% and 0.021% of S respectively, and then hot rolled at a surface temperature of 1040 ° C. , Hot rolled 2.3 mm plate, pickled, roll diameter 2
Cold rolled 70 mm to 0.30 mm, decarburized annealed in wet hydrogen at 830 ° C x 120 sec, nitrided annealed in hydrogen atmosphere containing ammonia, coated with MgO + 3% TiO 2 , dried, 1200 ° C x 2
A high temperature finishing high temperature annealing was performed for 0 hr. Table 3 shows the degree of occurrence of surface swelling defects and the magnetic flux density of this product.
第３表から分かるように鋼中Ｓのいずれについても表面
脹れ欠陥の発生の無いが、鋼中Ｓの0.021％と多い場合
は磁束密度が鋼中Ｓの低いものに比べ劣る。 As can be seen from Table 3, surface swelling defects do not occur in any of S in steel, but when the content of S in steel is as large as 0.021%, the magnetic flux density is inferior to that of S in steel that is low.
（発明の効果） 以上、詳述したように、本発明に従い、低温スラブ加熱
による製造技術を基盤に、熱延板焼鈍を省略して、直接
に冷間圧延する製造工程で表面脹れ欠陥がなく、しかも
磁束密度の劣化のほとんどない成品を、工業的に極めて
低コストで製造することができるので、本発明は工業的
に極めて有用である。(Effects of the Invention) As described in detail above, according to the present invention, on the basis of the manufacturing technology by low-temperature slab heating, hot-rolled sheet annealing is omitted, and surface swelling defects are generated in the manufacturing process of directly cold rolling. The present invention is extremely useful industrially because it can be manufactured industrially at a very low cost without any deterioration of the magnetic flux density.
第１図はC:0.045％,Si:3.30％,Mn:0.14％,P:0.022％,S:
0.007％，酸可溶性Al:0.031％,T.N:0.0078％，残部:Fe
および不可避的不純物から成る連続鋳造スラブを1150℃
に加熱後、2.3mmの熱延板とし、酸洗し、ロール直径が
それぞれ60mm,100mm,150mm,270mm,490mmである冷間圧延
ロールで0.30mmまで冷間圧延し、850℃×120secにて湿
水素中で脱炭焼鈍し、MgO＋３％TiO2＋７％窒化フェロ
マンガンを塗布し、乾燥し、1200℃×20hrの仕上高温焼
鈍を行なった時の成品の表面脹れ欠陥と線状二次再結晶
不良の発生程度をロール直径との関係で示す図である。 第２図は第１図中の冷間圧延ロール直径が100mmの場合
の成品の鋼板表面マクロ金属組織を示す写真図である。 第３図（Ａ），（Ｂ）は第２図の表面脹れ欠陥の圧延方
向延長上に隣接した冷延板、および脱炭焼鈍板の顕微鏡
金属組織を示す写真図である。Fig. 1 shows C: 0.045%, Si: 3.30%, Mn: 0.14%, P: 0.022%, S:
0.007%, acid soluble Al: 0.031%, TN: 0.0078%, balance: Fe
And continuous slabs consisting of inevitable impurities at 1150 ℃
After heating to 2.3 mm hot rolled plate, pickled, cold rolled to 0.30 mm with cold rolling rolls having roll diameters of 60 mm, 100 mm, 150 mm, 270 mm, and 490 mm, respectively, at 850 ° C x 120 sec Decarburization annealing in wet hydrogen, MgO + 3% TiO 2 + 7% ferromanganese nitride coated, dried, 1200 ° C x 20hr finish high temperature annealing It is a figure which shows the generation | occurrence | production degree of a crystal defect in relation with a roll diameter. FIG. 2 is a photograph showing the steel plate surface macro-metallographic structure of the product when the diameter of the cold rolling roll in FIG. 1 is 100 mm. FIGS. 3 (A) and 3 (B) are photographic views showing the microscopic metallographic structures of the cold-rolled sheet and the decarburized annealed sheet which are adjacent to each other in the rolling direction extension of the surface swelling defect of FIG.
Claims (4)
2〜0.040％,N≦0.0095％、残部Feおよび不可避的不純物
からなる珪素鋼スラブをスラブ中のAlとＮが完全には溶
体化しない温度域で加熱し、熱間圧延し、１回の冷間圧
延工程により最終板厚とし、次いで湿水素中で脱炭焼鈍
し、焼鈍分離剤を塗布し、二次再結晶と純化を目的とし
た仕上高温焼鈍を行なうことからなり、しかしてその
際、さらに脱炭焼鈍から二次再結晶開始迄のいずれかの
過程で窒化処理を行なう一方向性電磁鋼板の製造法にお
いて、冷間圧延を、熱延板焼鈍することなく直接に行な
い、その時の冷間圧延ロールの直径を150mm以上とする
ことを特徴とする表面脹れ欠陥の無い一方向性電磁鋼板
の製造法。1. Si: 1.5-6.7% by weight, acid-soluble Al: 0.01
2 to 0.040%, N ≤ 0.0095%, balance Fe and unavoidable impurities in the silicon steel slab is heated in a temperature range where Al and N in the slab are not completely solution-treated, hot rolled, and cooled once. The final plate thickness by the hot rolling process, followed by decarburizing annealing in wet hydrogen, applying an annealing separator, and performing secondary high temperature annealing for the purpose of secondary recrystallization and purification, in which case, Furthermore, in the manufacturing method of unidirectional electrical steel sheet in which nitriding is performed in any process from decarburization annealing to the start of secondary recrystallization, cold rolling is performed directly without hot-rolled sheet annealing, and the cold rolling at that time is performed. A method for producing a grain-oriented electrical steel sheet without surface bulging defects, characterized in that the diameter of the hot rolling roll is 150 mm or more.
温度で行なう請求項１記載の表面脹れ欠陥の無い一方向
性電磁鋼板の製造法。2. The method for producing a grain-oriented electrical steel sheet having no surface bulging defects according to claim 1, wherein the slab heating during hot rolling is performed at a temperature of less than 1280 ° C.
熱を利用して直接熱間圧延する請求項１記載の表面脹れ
欠陥の無い一方向性電磁鋼板の製造法。3. The method for producing a grain-oriented electrical steel sheet having no surface bulging defects according to claim 1, wherein the cast slab is directly hot-rolled by utilizing slab sensible heat without cooling.
下とする請求項１〜３の何れかに記載の表面脹れ欠陥の
無い一方向性電磁鋼板の製造法。4. The method for producing a grain-oriented electrical steel sheet having no surface swelling defect according to claim 1, wherein the S content of the silicon steel slab is 0.014% or less by weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1082233A JPH0730395B2 (en) | 1989-03-31 | 1989-03-31 | Manufacturing method of grain-oriented electrical steel sheet without surface bulge defect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1082233A JPH0730395B2 (en) | 1989-03-31 | 1989-03-31 | Manufacturing method of grain-oriented electrical steel sheet without surface bulge defect |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02259016A JPH02259016A (en) | 1990-10-19 |
| JPH0730395B2 true JPH0730395B2 (en) | 1995-04-05 |
Family
ID=13768691
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1082233A Expired - Lifetime JPH0730395B2 (en) | 1989-03-31 | 1989-03-31 | Manufacturing method of grain-oriented electrical steel sheet without surface bulge defect |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0730395B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010116936A1 (en) * | 2009-04-06 | 2010-10-14 | 新日本製鐵株式会社 | Method for treating steel for directional electromagnetic steel plate and method for producing directional electromagnetic steel plate |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0486707B1 (en) * | 1990-06-20 | 1998-12-23 | Nippon Steel Corporation | A Process for Producing an Ultrahigh Silicon, Grain-Oriented Electrical Steel Sheet and Steel Sheet obtainable with said Process |
| CN103695619B (en) | 2012-09-27 | 2016-02-24 | 宝山钢铁股份有限公司 | A kind of manufacture method of high magnetic strength common orientation silicon steel |
| JP5831435B2 (en) * | 2012-12-11 | 2015-12-09 | Ｊｆｅスチール株式会社 | Method for producing grain-oriented electrical steel sheets with excellent magnetic properties |
-
1989
- 1989-03-31 JP JP1082233A patent/JPH0730395B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010116936A1 (en) * | 2009-04-06 | 2010-10-14 | 新日本製鐵株式会社 | Method for treating steel for directional electromagnetic steel plate and method for producing directional electromagnetic steel plate |
| JP4673937B2 (en) * | 2009-04-06 | 2011-04-20 | 新日本製鐵株式会社 | Method for processing steel for grain-oriented electrical steel sheet and method for producing grain-oriented electrical steel sheet |
| US8202374B2 (en) | 2009-04-06 | 2012-06-19 | Nippon Steel Corporation | Method of treating steel for grain-oriented electrical steel sheet and method of manufacturing grain-oriented electrical steel sheet |
| KR101346537B1 (en) * | 2009-04-06 | 2013-12-31 | 신닛테츠스미킨 카부시키카이샤 | Method for treating steel for directional electromagnetic steel plate and method for producing directional electromagnetic steel plate |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02259016A (en) | 1990-10-19 |
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