JP3456352B2 - Grain-oriented electrical steel sheet with excellent iron loss characteristics and method of manufacturing the same - Google Patents

Grain-oriented electrical steel sheet with excellent iron loss characteristics and method of manufacturing the same

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Publication number
JP3456352B2
JP3456352B2 JP27813696A JP27813696A JP3456352B2 JP 3456352 B2 JP3456352 B2 JP 3456352B2 JP 27813696 A JP27813696 A JP 27813696A JP 27813696 A JP27813696 A JP 27813696A JP 3456352 B2 JP3456352 B2 JP 3456352B2
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JP
Japan
Prior art keywords
temperature
iron loss
annealing
rolling
steel 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 - Fee Related
Application number
JP27813696A
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Japanese (ja)
Other versions
JPH10121213A (en
Inventor
道郎 小松原
哲雄 峠
健一 定広
厚人 本田
邦浩 千田
Original Assignee
Jfeスチール株式会社
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Priority to JP27813696A priority Critical patent/JP3456352B2/en
Priority claimed from US08/954,504 external-priority patent/US6039818A/en
Publication of JPH10121213A publication Critical patent/JPH10121213A/en
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Publication of JP3456352B2 publication Critical patent/JP3456352B2/en
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Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/147Alloys characterised by their composition
    • H01F1/14766Fe-Si based alloys
    • H01F1/14775Fe-Si based alloys in the form of sheets
    • H01F1/14783Fe-Si based alloys in the form of sheets with insulating coating

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【発明の属する技術分野】この発明は、発電機や変圧器
の鉄心に利用される方向性電磁鋼板のなかでも、特に小
型発電機の鉄心やEIコアなどに用いて有利な鉄損特性
に優れる方向性電磁鋼板とその製造方法を提案するもの
である。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in iron loss characteristics particularly advantageous among grain-oriented electrical steel sheets used for iron cores of generators and transformers, especially for iron cores and EI cores of small generators. It proposes a grain-oriented electrical steel sheet and its manufacturing method.

【0002】Siを含有し、かつ、結晶方位が(110)
〔001〕方位や(100)〔001〕方位に配向した
方向性電磁鋼板は、優れた軟磁気特性を有することから
商用周波数域での各種鉄心材料として広く用いられてい
る。この時、電磁鋼板に要求される特性としては、一般
に50Hzの周波数で1.7 Tに磁化させた場合の損失である
W17/50 (W/kg)で表わされる鉄損が低いことが重要
で、大型変圧器の鉄心や巻鉄心の鉄損は W17/50 の値が
低い材料が実機での特性も優れているという結果を得て
いる。しかし、小型発電機の鉄心や小型変圧器であるE
Iコアなどの鋼板内部を流れる磁束が複雑な場合は、材
料の W17/50 であらわす鉄損と実機での鉄損特性が一致
しないという問題があった。
It contains Si and has a crystal orientation of (110)
The grain-oriented electrical steel sheet oriented in the [001] orientation or the (100) [001] orientation is widely used as various iron core materials in the commercial frequency range because it has excellent soft magnetic properties. At this time, the characteristic required for the electromagnetic steel sheet is generally the loss when magnetized to 1.7 T at a frequency of 50 Hz.
It is important that the iron loss expressed by W 17/50 (W / kg) is low, and the iron loss of large transformer cores and wound iron cores has a low value of W 17/50. The result is that However, E, which is a small generator core or small transformer,
When the magnetic flux flowing inside the steel plate such as the I-core is complicated, there was a problem that the iron loss represented by W 17/50 of the material and the iron loss characteristics in the actual machine did not match.

【0003】近年エネルギー危機の進行とともに変圧器
中で無駄に失うエネルギーの低減が要請され、実機の鉄
損を低減する努力がなされているなか、上記の場合材料
の W 17/50 では正当な評価が得られず、材料の選定にし
ばしば困難をきたしていた。
With the progress of the energy crisis in recent years, transformers
It is required to reduce energy lost in vain,
While efforts are being made to reduce losses, in the above cases materials
W 17/50In that case, a proper evaluation cannot be obtained.
It was sometimes difficult.

【0004】[0004]

【従来の技術】一般に材料の鉄損を低減するには、渦電
流損を低下させるために有効なSiを含有させ電気抵抗を
高める方法、鋼板板厚を低減する方法、結晶粒径を低減
する方法、さらに結晶方位の集積度を高めて磁束密度を
向上させる方法などが知られている。
2. Description of the Related Art Generally, in order to reduce iron loss of a material, a method of increasing electric resistance by containing Si which is effective for reducing eddy current loss, a method of reducing a steel plate thickness, and a grain size are reduced. A method, a method of improving the magnetic flux density by further increasing the degree of integration of crystal orientations, and the like are known.

【0005】これらのうち、磁束密度を向上させる手法
についてはこれまで数多く研究されてきており、例え
ば、特公昭51−2290号公報(高磁束密度一方向性
電磁鋼板の熱間圧延方法)には鋼中にインヒビター成分
としてAlを添加し、1300℃以上の高温でスラブ加熱し、
熱間仕上げ圧延を高温短時間で行い、980 ℃以上の熱間
圧延終了温度で熱間圧延を行う技術が、また、特公昭4
6−23820号公報(高磁束密度電磁鋼板の熱処理
法)には、鋼中にAlを添加し、熱間圧延後1000〜1200℃
と高温での熱延板焼鈍とそれに伴う急冷処理によって微
細なAlN を析出させ、80〜95%の高圧下率を施す技術が
開示され、これによって、B10にて1.95Tと極めて高い
磁束密度と低鉄損の材料を得ている。
Among these, many methods have been studied so far for improving the magnetic flux density, and for example, Japanese Patent Publication No. 51-2290 (hot rolling method for high magnetic flux density unidirectional electrical steel sheet). Add Al as an inhibitor component to steel and heat the slab at a high temperature of 1300 ° C or higher,
A technique for performing hot finish rolling at high temperature in a short time and hot rolling at a hot rolling finish temperature of 980 ° C or higher is also disclosed in JP-B-4.
No. 6-23820 (heat treatment method for high magnetic flux density magnetic steel sheet), Al is added to the steel and 1000-1200 ° C. after hot rolling.
Very high magnetic flux density and to precipitate a fine AlN by hot-rolled sheet annealing and quenching process associated therewith at high temperatures, is disclosed a technique of applying a high pressure ratio of 80% to 95%, whereby at B 10 and 1.95T And have obtained a material with low iron loss.

【0006】しかしながら、 W17/50 の低減の際に従来
から追究されてきた通常の結晶方位を揃え磁束密度を向
上させる手法は、EIコアや小型発電機の鉄心の鉄損特
性を向上させるには有効な手法とはいえなかった。
However, when reducing W 17/50 , the conventional method of aligning the normal crystal orientations and improving the magnetic flux density is to improve the iron loss characteristics of the EI core and the iron core of a small generator. Was not an effective method.

【0007】[0007]

【発明が解決しようとする課題】前記したようなことか
ら、磁束密度を向上させる手法にかわるものとして、Si
含有量を増加させる手法、鋼板板厚を低減する手法、結
晶粒径を低減する手法を検討したが、このうち、Si含有
量を増加させる手法についてはSiを過度に含有させると
圧延性や加工性を劣化させるので好ましくなく限界があ
り、また鋼板板厚を低減する方法も極端な製造コストの
増大をもたらすので自ずから限界があった。
From the above, as an alternative to the method for improving the magnetic flux density, Si
We examined methods of increasing the content, methods of reducing the steel plate thickness, and methods of reducing the crystal grain size. Among these, the method of increasing the Si content was found to contain too much Si for rollability and workability. There is not preferable limitations because degrading the sex, also there is a limit from the self not a in the a method of reducing the steel sheet thickness results in an increase in the extreme manufacturing cost.

【0008】そこで、この発明のうち請求項1ないし2
の発明は、製品の結晶粒径分布およびフォルステライト
質被膜の成分組成を最適化することによる鉄損特性、特
に磁束密度1.7 Tの高磁場に比し磁束密度1.0 Tの低磁
場の鉄損特性に優れる方向性電磁鋼板を提案することを
目的とするものであり、請求項3ないし5の発明はその
方向性電磁鋼板の製造方法を提案することを目的とする
ものである。
Therefore, the invention according to claim 1 or 2
Of the present invention, the iron loss characteristics by optimizing the grain size distribution of the product and the component composition of the forsterite coating ,
It is an object of the present invention to propose a grain-oriented electrical steel sheet which is excellent in iron loss characteristics in a low magnetic field having a magnetic flux density of 1.0 T as compared with a high magnetic field having a magnetic flux density of 1.7 T. The purpose of the present invention is to propose a method for manufacturing a magnetic electrical steel sheet.

【0009】なお、従来から広く知られている方向性電
磁鋼板の結晶粒径の制御技術は、例えば、特公昭59−
20745号公報(鉄損の極めて低い一方向性珪素鋼板
とその製造方法)に平均結晶粒径を1〜6mmとする薄手
の方向性電磁鋼板の製造方法が、特公昭62−5692
3号公報(鉄損の少ない一方向性珪素鋼板の製造方法)
には粒径が2mm以下の結晶粒の個数比率を15〜70%とし
鉄損を低減する手法が、さらに、特公平6−80172
号公報(鉄損の低い方向性けい素鋼板およびその製造方
法)には粒径が1.0 mm以上2.5 mm以下の微細粒を混粒状
に存在させることにより鉄損を低減する技術が、それぞ
れ提案開示されているが、これらはいずれも磁束密度1.
7 Tの高磁場での鉄損 W17/50 の低減を目的としたもの
であり、低磁場での鉄損について検討されたものではな
い。
A well-known technique for controlling the crystal grain size of grain-oriented electrical steel sheets is disclosed in, for example, Japanese Patent Publication No.
A method for manufacturing a thin grain-oriented electrical steel sheet having an average crystal grain size of 1 to 6 mm is disclosed in Japanese Patent Publication No. 62-5692.
Publication No. 3 (Method for manufacturing unidirectional silicon steel sheet with low iron loss)
In order to reduce iron loss, the number ratio of crystal grains with a grain size of 2 mm or less should be 15-70%.
Japanese Patent Publication (oriented silicon steel sheet with low iron loss and method of manufacturing the same) proposes technologies for reducing iron loss by allowing fine particles with a grain size of 1.0 mm or more and 2.5 mm or less to exist in a mixed grain form. However, these are all magnetic flux density 1.
The purpose is to reduce the iron loss W 17/50 in a high magnetic field of 7 T, and the iron loss in a low magnetic field has not been studied.

【0010】[0010]

【課題を解決するための手段】発明者らは鋭意研究の結
果、高磁場での鉄損 W17/50 を増加し、低磁場での鉄損
W10/50 を低減する、すなわち、 W10/50 / W17/50
値を低減すること、そのためには、製品の金属組織の結
晶粒径分布として、一定値以下の微細粒と粗大粒の個数
比率を適格に制御すること、および鋼板表面にAl、Tiお
よびBを適量含有するフォルステライトを主成分とする
被膜を形成させることにより達成できることを新規に見
い出しこの発明に至ったものである。すなわち、この発
明の要旨とするところは以下のとおりである。
[Means for Solving the Problems] As a result of diligent research, the inventors increased iron loss W 17/50 in a high magnetic field and increased iron loss in a low magnetic field.
To reduce W 10/50 , that is, to reduce the value of W 10/50 / W 17/50 , in order to reduce the grain size distribution of the metal structure of the product, fine grains and coarse grains below a certain value The present invention has been newly found out that this can be achieved by appropriately controlling the number ratio of the above, and by forming a film containing forsterite as a main component containing Al, Ti and B in appropriate amounts on the surface of the steel sheet. . That is, the gist of the present invention is as follows.

【0011】 Si:1.5 〜7.0 wt%およびMn:0.03〜
2.5 wt%を含有し、C,SおよびNの含有量をそれぞれ
C:0.003 wt%以下、S:0.002 wt%以下およびN:0.
002wt%以下とし、残部Feおよび不可避的不純物からな
電磁鋼板であって、該鋼板の板厚方向に貫通する結晶
粒の鋼板面内方向の粒径の個数比率が、1mm未満:25〜
98%、4mm以上7mm未満:45%以下および7mm以上:10
%以下であり、該鋼板表面にはフォルステライト質被膜
を有し、その被膜中にAl:0.5 〜15wt%、Ti:0.1 〜10
wt%およびB:0.01〜0.8 wt%を含有していることを特
徴とする鉄損特性に優れる方向性電磁鋼板(第1発
明)。
Si: 1.5-7.0 wt% and Mn: 0.03-
It contains 2.5 wt% and the contents of C, S and N are C: 0.003 wt% or less, S: 0.002 wt% or less and N: 0.
002wt% or less , the balance Fe and unavoidable impurities
An electromagnetic steel sheet according to claim 1, wherein the number ratio of grain sizes of crystal grains penetrating in the plate thickness direction in the steel plate in-plane direction is less than 1 mm: 25 to
98%, 4 mm or more and less than 7 mm: 45% or less and 7 mm or more: 10
% Or less, a forsterite coating is provided on the surface of the steel sheet, and Al : 0.5 to 15 wt% and Ti: 0.1 to 10% in the coating.
wt% and B: 0.01 to 0.8 wt% are contained in the grain-oriented electrical steel sheet having excellent iron loss characteristics (first invention).

【0012】 さらにSb:0.0010〜0.080 wt%を含有
することを特徴とする第1発明に記載の鉄損特性に優れ
る方向性電磁鋼板(第2発明)。
Further, Sb: 0.0010 to 0.080 wt% is contained
The grain-oriented electrical steel sheet having excellent iron loss characteristics according to the first aspect of the invention (second aspect of the invention).

【0013】 C:0.005 〜0.070 wt%、 Si:1.5 〜7.0 wt%、 Mn:0.03〜2.5 wt%、 Al:0.005 〜0.017 wt%および N:0.0030〜0.0100wt% を含み、かつ、Ti,Nb,BまたはSbのうちから選ばれる
1種または2種以上をそれぞれ Ti:0.0005〜0.0020wt% Nb:0.0010〜0.010 wt% B:0.0001〜0.0020wt%および Sb:0.0010〜0.080 wt% で含有し、残部Feおよび不可避的不純物からなる溶鋼を
鋳造してけい素鋼スラブとなし、該スラブを素材として
1250℃以下の温度に加熱して熱間圧延を行うかもしくは
直接熱間圧延して800 〜970 ℃の温度範囲で仕上げ圧延
を終了したのち、10℃/s以上の冷却速度で急冷して67
0 ℃以下の温度でコイルに巻取り、その後、昇温速度:
5〜25℃/sの範囲で昇温し800 〜950 ℃の温度範囲で
100 秒間以下保持する熱延板焼鈍を施したのち、タンデ
ム圧延機により圧下率:80〜95%の冷間圧延後、1次再
結晶焼鈍を施し、Ti化合物:1〜20wt%およびB:0.04
〜1.0 wt%を含有する焼鈍分離剤を塗布してから、昇温
途中の少なくとも850 ℃以上の温度からはH2 を含有す
る雰囲気中で昇温・保持する最終仕上げ焼鈍を施すこと
を特徴とする鉄損特性に優れる方向性電磁鋼板の製造方
法(第3発明)。
C: 0.005-0.070 wt%, Si: 1.5-7.0 wt%, Mn: 0.03-2.5 wt%, Al: 0.005-0.017 wt% and N: 0.0030-0.0100 wt%, and Ti, Nb , B or Sb selected from the group consisting of Ti: 0.0005 to 0.0020 wt% Nb: 0.0010 to 0.010 wt% B: 0.0001 to 0.0020 wt% and Sb: 0.0010 to 0.080 wt% , respectively. Molten steel consisting of balance Fe and unavoidable impurities is cast into a silicon steel slab, and the slab is used as a raw material.
After heating to a temperature of 1250 ° C or lower for hot rolling or direct hot rolling to finish rolling in the temperature range of 800 to 970 ° C, quenching is performed at a cooling rate of 10 ° C / s or more to 67
The coil is wound at a temperature of 0 ° C or less, and then the heating rate:
In the temperature range of 800 to 950 ℃, the temperature is raised in the range of 5 to 25 ℃ / s.
After hot-rolled sheet annealing for 100 seconds or less, cold rolling with a tandem rolling mill at a rolling reduction of 80 to 95%, primary recrystallization annealing, and Ti compound: 1 to 20 wt% and B: 0.04
It is characterized in that after applying an annealing separator containing 1.0 wt% to 1.0 wt%, a final finish annealing is performed in which the temperature is raised and held in an atmosphere containing H 2 from a temperature of at least 850 ° C. or higher during heating. Method for producing a grain-oriented electrical steel sheet having excellent iron loss characteristics (third invention).

【0014】 溶鋼が、さらにCrまたはSnの1種また
は2種を、 Cr:0.0010〜0.30wt%および Sn:0.0010〜0.30wt% で含有することを特徴とする第3発明に記載の高磁場に
比し低磁場の鉄損特性に優れる方向性電磁鋼板の製造方
法(第4発明)。
In the high magnetic field according to the third invention, the molten steel further contains one or two kinds of Cr or Sn at Cr: 0.0010 to 0.30 wt% and Sn: 0.0010 to 0.30 wt%. In comparison, a method for producing a grain-oriented electrical steel sheet which is excellent in iron loss characteristics in a low magnetic field (fourth invention).

【0015】 鋳造時に電磁攪拌を施すことを特徴と
する第3または第4発明に記載の高磁場に比し低磁場の
鉄損特性に優れる方向性電磁鋼板の製造方法(第5発
明)。
A method for manufacturing a grain-oriented electrical steel sheet having excellent iron loss characteristics in a low magnetic field as compared with a high magnetic field according to the third or fourth invention, which is characterized by performing electromagnetic stirring during casting (fifth invention).

【0016】ここで、焼鈍分離剤に含有させるTi化合物
とは、 TiO2 , TiS, MgTiO3 などTiを含む化合物を意味
し、Bとしては、MgO 中に固溶している状態や、nMgO・
B2O 3 等の化合物でMgO 中に存在している状態のほか、
焼鈍分離剤へ添加物として含有させることもよい。
Here, the Ti compound contained in the annealing separator.
And is TiO2, TiS, MgTiO3Means compounds containing Ti, etc.
However, as B, the state of solid solution in MgO or nMgO.
 B2O 3In addition to the state existing in MgO with compounds such as
It may be added as an additive to the annealing separator.

【0017】[0017]

【発明の実施の形態】まず、この発明に至った実験例に
ついて以下に述べる。
BEST MODE FOR CARRYING OUT THE INVENTION First, experimental examples that have led to the present invention will be described below.

【0018】予備実験として、実機の小型発電機の鉄心
やEIコアの鉄損について材料評価のよい指標について
検討したところ、表1に示すように高磁場での鉄損の劣
化を許容し低磁場での鉄損が良好なこと、すなわち、 W
10/50 (1.0 Tの磁束密度における鉄損:W/kg)/ W
17/50 の値と実機の特性とがよい相関を有することが判
明した。
As a preliminary experiment, a good index for material evaluation of the iron core of the small generator of the actual machine and the iron loss of the EI core was examined. As shown in Table 1, deterioration of the iron loss in a high magnetic field was allowed and a low magnetic field was allowed. Good iron loss at W
10/50 (Iron loss at 1.0 T magnetic flux density: W / kg) / W
It was found that the value of 17/50 and the characteristics of the actual machine have a good correlation.

【0019】[0019]

【表1】 [Table 1]

【0020】この理由は、実機の場合鋼板内を流れる磁
束の分布が不均一であるため、低磁場での鉄損がより重
要で、高磁場での鉄損はむしろ高い方が実機全体におけ
る磁束の流れがより均一化する方向に改善され、結果的
に実機の鉄損を低減することになるためと思われる。ま
た、表1において良好な実機特性を示した材料aおよび
bについて調査したところ、結晶組織が細粒になってい
ることがわかった。
The reason for this is that, in the case of an actual machine, the distribution of the magnetic flux flowing in the steel sheet is non-uniform, so iron loss in a low magnetic field is more important, and iron loss in a high magnetic field is rather high. It is thought that this is because the flow of is improved to be more uniform, and as a result, the iron loss of the actual machine is reduced. Further, when the materials a and b which showed good actual machine properties in Table 1 were investigated, it was found that the crystal structure was fine grain.

【0021】ここで、従来より鉄損の低減に結晶粒径が
小さい方が有利であるという知識はあっても、前記した
ように、これまではすべてが材料の高磁場での鉄損 W
17/50の低減に関する研究であって、EIコアなどの鉄
損を低減するといった小型電気機器類の実機特性を向上
させるという観点からの研究はなく、とくに、鉄損 W17
/50 の増加を許容し鉄損 W10/50 や W10/50 / W17/50
の値を低減するといった観点から、結晶粒径を如何なる
サイズと分布に制御すべきかといった研究は皆無であ
り、そのための適正な結晶粒径の分布は明確にはなって
いなかった。
Here, although it is known that it is advantageous to reduce the crystal grain size to reduce the iron loss as compared with the prior art, as described above, all of the iron loss W of the material in the high magnetic field has been described so far.
There is no research from the viewpoint of improving the actual machine characteristics of small electric devices such as reducing iron loss such as EI core, especially iron loss W 17
Allowing an increase of / 50 , iron loss W 10/50 or W 10/50 / W 17/50
There has been no research on what size and distribution of the crystal grain size should be controlled from the viewpoint of reducing the value of, and the proper distribution of the crystal grain size for that purpose has not been clarified.

【0022】この予備実験結果をもとに、製品での鉄損
ならびに W10/50 および W10/50 /W17/50 の値を低減
するための鋼板結晶粒径分布やその製造条件などについ
て種々実験・検討を行った。
Based on the results of this preliminary experiment, the steel grain size distribution and manufacturing conditions for reducing the iron loss in products and the values of W 10/50 and W 10/50 / W 17/50 Various experiments and studies were conducted.

【0023】実験1(Al含有量、熱間圧延条件および熱
延板焼鈍条件の検討) 表2に示した鋼記号Iの成分組成になるスラブ10本を、
表3に示した記号a〜jの条件でそれぞれ熱間圧延し板
厚:2.4 mmの熱延板コイルとし、従来の製造法として表
2の鋼記号III の成分組成になるスラブを表3の記号h
に示した条件で熱間圧延し同じく板厚:2.4 mmの熱延板
コイルとした。
Experiment 1 (Study of Al content, hot rolling conditions and hot rolled sheet annealing conditions) Ten slabs having the chemical composition of steel symbol I shown in Table 2 were prepared.
Hot-rolled sheets having a thickness of 2.4 mm were hot-rolled under the conditions of symbols a to j shown in Table 3, and slabs having the composition of steel symbol III in Table 2 as a conventional manufacturing method are shown in Table 3. Symbol h
Hot-rolling was performed under the conditions shown in (1) to obtain a hot-rolled sheet coil with a sheet thickness of 2.4 mm.

【0024】[0024]

【表2】 [Table 2]

【0025】[0025]

【表3】 [Table 3]

【0026】なお、熱間圧延終了時からコイル巻取りま
での間の冷却は全て、冷却速度:25.3〜28.6℃/sの範
囲の急冷とした。
All the cooling from the end of hot rolling to the coil winding was done by quenching at a cooling rate of 25.3 to 28.6 ° C./s.

【0027】その後、これらのコイルは全て2分割し、
一方は900 ℃・60秒間、他方は1050℃・60秒間の熱延板
焼鈍を施したのち、酸洗し、タンデム圧延機により150
℃の温度で板厚:0.34mmに温間圧延後、脱脂処理を行い
850 ℃・2分間の脱炭焼鈍を施し、0.1 %のBを含有す
るMgO 中に TiO2 を5%添加した焼鈍分離剤を塗布して
から、昇温時600 ℃の温度までをN2 単独の雰囲気、そ
の後、1050℃の温度まではN2 :25%、H2 :75%の混
合雰囲気、以後、H2 単独の雰囲気で1200℃の温度まで
昇温後5時間保持する最終仕上げ焼鈍を施したのち、そ
れぞれ未反応焼鈍分離剤を除去した。
After that, these coils are all divided into two,
One is hot-rolled sheet annealing at 900 ° C for 60 seconds and the other at 1050 ° C for 60 seconds, then pickled, and then tandem
After hot rolling at a temperature of ℃ to a thickness of 0.34 mm, degreasing is performed.
After decarburization annealing at 850 ° C for 2 minutes and applying an annealing separator containing 5% of TiO 2 in MgO containing 0.1% of B, N 2 alone is heated up to a temperature of 600 ° C. Atmosphere, then a mixed atmosphere of N 2 : 25% and H 2 : 75% up to a temperature of 1050 ° C., and then a final finishing annealing in which H 2 alone is heated to a temperature of 1200 ° C. and held for 5 hours. After the application, the unreacted annealing separator was removed.

【0028】ついで、これらの鋼板に40%のコロイダル
シリカを含有するりん酸マグネシウムを主成分とする絶
縁コーテイングを塗布し800 ℃の温度で焼付けそれぞれ
製品とした。
Next, an insulating coating containing magnesium phosphate containing 40% of colloidal silica as a main component was applied to these steel sheets and baked at a temperature of 800 ° C. to obtain respective products.

【0029】しかるのち、上記の未反応焼鈍分離剤を除
去した各鋼板をマクロエッチして結晶粒径分布をそれぞ
れ測定するとともに、各製品より圧延方向に沿ってエプ
スタインサイズの試験片を切り出し800 ℃の温度で3時
間の歪取り焼鈍を施したのち、1.0 Tおよび1.7 Tの磁
束密度における鉄損 W10/50 および W17/50 ならびに磁
束密度B8 をそれぞれ測定した。また、各製品からEI
コア用の鉄心を打抜き、歪取り焼鈍を施したのち、積み
加工、銅線の巻加工などによってEIコアをそれぞれ作
製し、これらのEIコアの鉄損特性についても調査し
た。これらの調査結果を表4にまとめて示す。
Thereafter, the steel plates from which the above unreacted annealing separator has been removed are macro-etched to measure the grain size distribution, and Epstein-sized test pieces are cut out from each product along the rolling direction at 800 ° C. After the strain relief annealing was performed at the temperature of 3 hours, the iron loss W 10/50 and W 17/50 and the magnetic flux density B 8 at the magnetic flux densities of 1.0 T and 1.7 T were measured, respectively. Also, from each product, EI
The cores for cores were punched out, subjected to strain relief annealing, and then EI cores were produced by stacking, copper wire winding, etc., and the iron loss characteristics of these EI cores were also investigated. The results of these investigations are summarized in Table 4.

【0030】[0030]

【表4】 [Table 4]

【0031】表4より、従来例の成分組成のスラブ(鋼
記号III)を素材とし、従来例の熱間圧延条件(記号h)
で製造した仕上げ焼鈍後の鋼板は(結晶粒径分布は仕上
げ焼鈍後絶縁コーティングを焼付けて製品にしても変化
しない)、粒径が7mm以上の粗大結晶粒の個数比率が大
きく、かつ、磁束密度B8 も1.96Tと高い製品である
が、鉄損特性について見ると、高磁場での鉄損 W17/50
が極めて小さいのに対し、低磁場での鉄損 W10/50 が比
較的大きく、したがって、 W10/50 / W17/50 の値が大
きく低磁場での鉄損に優れているとはいえない。
From Table 4, the slab (steel symbol III) having the composition of the conventional example is used as the material, and the hot rolling conditions (symbol h) of the conventional example are used.
The steel sheet after finish annealing manufactured in (the grain size distribution does not change even after baking the insulating coating after finish annealing) has a large number ratio of coarse crystal grains with a grain size of 7 mm or more, and the magnetic flux density. B 8 is also a high product of 1.96 T, but looking at the iron loss characteristics, iron loss in high magnetic field W 17/50
Is extremely small, but the iron loss W 10/50 in the low magnetic field is relatively large, and therefore the value of W 10/50 / W 17/50 is large and it can be said that the iron loss in the low magnetic field is excellent. Absent.

【0032】これに対し、Nbを微量添加し、かつAl含有
量の少ないこの発明に適合する成分組成のスラブ(鋼記
号I)を素材とし、スラブ加熱温度:1200℃以下、熱間
圧延終了温度:950 ℃以下(800 ℃以上)、熱延板焼鈍
温度:900 ℃として製造した製品(表4中の備考欄に良
好と記したもの)は、高磁場での鉄損は大きいが、低磁
場での鉄損が低く、したがって W10/50 / W17/50 の値
も小さく、かつEIコアとしての鉄損も極めて良好であ
る。これらの製品の結晶組織の特徴は結晶粒径が従来製
法のものより小さい点にあり、4mm未満特に1mm未満の
微細粒の個数比率が大きいことがわかる。
On the other hand, a slab (steel code I) having a composition that complies with the present invention and containing a small amount of Nb and a small Al content is used as a material, and the slab heating temperature is 1200 ° C. or less and the hot rolling end temperature is : Products manufactured at 950 ° C or lower (800 ° C or higher) and hot-rolled sheet annealing temperature: 900 ° C (marked as good in the remarks column in Table 4) have large iron loss in high magnetic fields, but low magnetic fields The core loss is low and therefore the value of W 10/50 / W 17/50 is also small, and the core loss as an EI core is also very good. The characteristic of the crystal structure of these products is that the crystal grain size is smaller than that of the conventional manufacturing method, and it is understood that the number ratio of fine grains of less than 4 mm, particularly less than 1 mm is large.

【0033】この点について実験・検討を進めた結果、
1mm未満の粒径の結晶粒の個数比率を25%以上とするこ
とが必要であることがわかった。ただし、このような微
細粒の過剰な存在は磁気特性を大きく劣化させ W10/50
の値そのものを劣化させることも明らかとなった。ちな
みに、表4のこの発明に適合する鋼(鋼記号I)を素材
として、熱間圧延終了温度が低く過ぎたり高過ぎたり、
あるいは熱延板焼鈍温度が高過ぎた条件で製造した製品
などで、1mm未満の粒径の微細結晶粒の個数比率が98%
を超える場合には、 W10/50 および W10/50 / W17/50
の値が著しく劣化し、EIコアとしての鉄損特性も劣っ
ている。したがって、粒径が1mm未満の結晶粒の個数比
率としては25〜98%に制御することが必要になる。
As a result of conducting experiments and studies on this point,
It was found that it is necessary to set the number ratio of crystal grains having a grain size of less than 1 mm to 25% or more. However, the excessive presence of such fine particles significantly deteriorates the magnetic properties and W 10/50
It also became clear that it deteriorates the value of. By the way, using a steel (steel symbol I) compatible with the invention of Table 4 as a material, the hot rolling end temperature is too low or too high,
Alternatively, for products manufactured under conditions where the hot-rolled sheet annealing temperature is too high, the number ratio of fine crystal grains with a grain size of less than 1 mm is 98%.
W 10/50 and W 10/50 / W 17/50
Value is significantly deteriorated, and the iron loss characteristics of the EI core are also inferior. Therefore, it is necessary to control the number ratio of crystal grains having a grain size of less than 1 mm to 25 to 98%.

【0034】さらに、1mm以上の粒径の結晶粒について
もできるだけ細粒とすることが重要で、粗大な結晶粒の
出現を抑制し、結晶粒径分布を適格な範囲に制御するこ
とが肝要であることがわかった。
Further, it is important to make the crystal grains having a grain size of 1 mm or more as fine as possible, and it is important to suppress the appearance of coarse crystal grains and control the grain size distribution within a proper range. I knew it was.

【0035】ついで、上記したように微細結晶粒の個数
比率を高め、結晶粒径分布を適正化することにより、良
好な低磁場での鉄損特性が得られた理由について、さら
に種々の検討を加えた。
Next, various studies will be further conducted on the reason why good iron loss characteristics in a low magnetic field were obtained by increasing the number ratio of fine crystal grains and optimizing the crystal grain size distribution as described above. added.

【0036】まず、第1にインヒビターとしてのAlN の
析出方法が新規であり、極めて微細かつ均一にAlN を分
散できた点が挙げられる。そして、これにより1mm未満
の結晶粒を存在させつつも安定して2次再結晶をさせる
ことかできたものと考えられる。
First, the method of precipitating AlN as an inhibitor is novel, and it is possible to disperse AlN extremely finely and uniformly. It is considered that, as a result, the secondary recrystallization could be stably performed even though the crystal grains of less than 1 mm were present.

【0037】従来より行われていたAlN の析出方法は、
前掲特公昭46−23820号公報に開示されているよ
うに、熱延板焼鈍においてAlN を固溶状態とし、熱延板
焼鈍の冷却過程で再析出させ、その際の冷却速度を制御
することによりAlN の析出サイズを制御する方法であ
る。これに対し、この実験で良好な結果を得たAlN の析
出方法は、熱間圧延まではAlN を固溶状態に保ち、熱延
板焼鈍の昇温過程においてAlNを析出させる斬新な方法
である。
The AlN precipitation method which has been conventionally performed is as follows.
As disclosed in Japanese Examined Patent Publication No. 46-23820, by making AlN into a solid solution state in hot-rolled sheet annealing, re-precipitating in the cooling process of hot-rolled sheet annealing, and controlling the cooling rate at that time. This is a method to control the precipitation size of AlN. On the other hand, the AlN precipitation method that has obtained good results in this experiment is a novel method of keeping AlN in a solid solution state until hot rolling and precipitating AlN in the temperature rising process of hot-rolled sheet annealing. .

【0038】かかる方法において、AlN を微細に析出さ
せるためには、AlN の溶解度積を低下させるため、Al含
有量を従来の好適な値より少なくし、AlN の析出温度を
低温化して熱間圧延工程で析出しにくくし、かつ、熱間
圧延終了温度を800 ℃以上、熱延板コイル巻取り温度を
670 ℃以下としAlN の熱間圧延工程での析出を抑制する
ことが必要になる。なお、コイル巻取り温度を低温に保
つ必要性は、巻取り温度が高い場合過飽和状態のAlN が
析出するので、これを抑制するためである。
In such a method, in order to finely precipitate AlN, the solubility product of AlN is lowered, so that the Al content is made smaller than the conventional suitable value, the precipitation temperature of AlN is lowered, and hot rolling is performed. Prevents precipitation during the process, sets the hot rolling finish temperature to 800 ° C or more, and sets the hot-rolled coil winding temperature.
It is necessary to suppress the precipitation of AlN in the hot rolling process at 670 ° C or lower. The need to keep the coil winding temperature low is to suppress the supersaturated AlN 3 that precipitates when the coiling temperature is high.

【0039】さらに、熱間圧延後の過飽和状態にあるAl
N の析出を抑制するためには、当然熱間圧延終了後から
コイル巻取りまでの間の冷却速度も速いことが要求さ
れ、この目的のためには、冷却速度として10℃/s以上
が必要であることがわかった。
Further, Al in a supersaturated state after hot rolling
In order to suppress the precipitation of N, it is naturally required that the cooling rate from the end of hot rolling to the coil winding is also high. For this purpose, a cooling rate of 10 ° C / s or more is required. I found out.

【0040】また、熱延板焼鈍としては、1150℃の温度
といったAlN の固溶を狙った従来のような高温の焼鈍は
ことのほか有害であり、加えて昇温過程で析出させた微
細なAlN のオストワルド成長をも抑制するためには焼鈍
温度としては950 ℃以下と従来では全く不適とされてい
た極めて低い温度が適合する結果となった。
Further, as the hot-rolled sheet annealing, the conventional high-temperature annealing such as the temperature of 1150 ° C. which aims at the solid solution of AlN is extremely harmful, and in addition, the fine particles precipitated during the temperature rising process are added. In order to suppress the Ostwald growth of AlN as well, the annealing temperature was 950 ° C or less, which is extremely low, which was completely unsuitable in the past.

【0041】第2の革新的技術としては、好適な2次再
結晶を得るための1次再結晶組織の改善である。従来よ
り2次再結晶粒の急激な成長のためには蚕食される1次
再結晶粒のサイズが均一で小さいことが有利であること
が知られている。さらに1次再結晶粒のサイズが増大す
る原因および不均一性が増大する原因としては、熱間圧
延や冷間圧延前の段階での鋼材の結晶粒の粗大化が原因
であることも従来より良く知られていることである。し
かしながら、熱間圧延前では、インヒビターの固溶のた
めに高温スラブ加熱を行うことが必然であり、これに伴
って熱間圧延前鋼材の結晶粒径は当然のことながら増大
する。このため、インヒビターの粒成長抑制力が弱い場
合は1次再結晶粒径は当然のこととして増大し、例えば
特開平6−172861号公報(磁気特性の優れた厚い
板厚の一方向性電磁鋼板の製造方法)に示されているよ
うに、1次再結晶粒径は18〜35μm といった粗大なもの
になる。
The second innovative technique is to improve the primary recrystallization structure to obtain a suitable secondary recrystallization. It has been conventionally known that it is advantageous that the size of the primary recrystallized grains that are eroded by the silkworm is uniform and small in order to rapidly grow the secondary recrystallized grains. Further, as a cause of increasing the size of primary recrystallized grains and a cause of increasing non-uniformity, coarsening of crystal grains of steel material in a stage before hot rolling or cold rolling is also a cause. It is well known. However, before hot rolling, high temperature slab heating is inevitable for solid solution of the inhibitor, and of course, the crystal grain size of the steel material before hot rolling increases. Therefore, the primary recrystallized grain size naturally increases when the inhibitor grain growth suppressing force is weak, and for example, JP-A-6-172861 (a thick unidirectional electrical steel sheet having excellent magnetic properties). Production method), the primary recrystallized grain size becomes as coarse as 18 to 35 μm.

【0042】かかる点からも、上記実験で良好な低磁場
での鉄損特性を得た条件が、1200℃前後といった低温の
スラブ加熱温度、900 ℃前後といった低温の熱延板焼鈍
条件にしめされるように、これらは、熱間圧延前や冷間
圧延前の鋼材の結晶粒の成長を抑え1次再結晶組織の細
粒化および均一化を得るためには絶好の条件であり、画
期的な技術といえる。
From this point of view, the conditions for obtaining the good iron loss characteristics in the low magnetic field in the above experiment are indicated by the slab heating temperature as low as around 1200 ° C. and the annealing condition of the hot rolled sheet as low as around 900 ° C. As described above, these are the best conditions for suppressing the growth of crystal grains of the steel material before hot rolling or cold rolling to obtain the finer and more uniform primary recrystallization structure. It can be said to be a technical technology.

【0043】さらに、熱間圧延前鋼材の結晶粒を粗大化
させないという観点からは、鋼の鋳造組織が細かいこと
がより効果的であり、例えば、鋳造中の溶湯に電磁攪拌
処理を施して柱状晶の発達を抑制する方法は、その効果
が絶大である。また、スラブを加熱しないで直接圧延す
る方法もこの観点から好ましい。
Further, from the viewpoint of not coarsening the crystal grains of the steel material before hot rolling, it is more effective that the cast structure of the steel is fine. For example, the molten metal during casting is subjected to electromagnetic stirring treatment to form a columnar shape. The method of suppressing the growth of crystals has a great effect. A method of directly rolling the slab without heating it is also preferable from this viewpoint.

【0044】実験2(AlN 析出核生成成分の影響および
熱延板昇温速度の影響) 熱延板焼鈍の昇温過程におけるAlN の微細析出に関する
実験・検討を行った。前掲表2に示した鋼記号XIの成分
組成になるスラブ6本および鋼記号Vの成分組成になる
スラブ1本を、それぞれ前掲表3の記号bに示した条件
で熱間圧延し、板厚:2.4 mmの熱延板コイルとした。こ
のとき、熱間圧延終了時からコイル巻取り時までの間の
冷却速度は26.5℃/sとした。
Experiment 2 (Influence of AlN Precipitating Nucleation Component and Effect of Hot Rolling Rate of Hot Rolled Sheet) Experiments and studies were carried out on fine precipitation of AlN in the temperature rising process of hot rolled sheet annealing. Six slabs having the composition of the steel symbol XI shown in Table 2 above and one slab having the composition of the steel symbol V were hot-rolled under the conditions shown in the symbol b of the above Table 3 to obtain the sheet thickness. : A 2.4 mm hot rolled sheet coil was used. At this time, the cooling rate from the end of hot rolling to the coil winding was 26.5 ° C / s.

【0045】これらの熱延板に900 ℃・60秒間の熱延板
焼鈍を施したが、このとき鋼記号XIのスラブを用いた熱
延板については、2.5, 3.7, 5.4, 12.7, 23 および28℃
/sとそれぞれ昇温速度を変更し、鋼記号Vのスラブを
用いた熱延板については、12.2℃/sの昇温速度とし
た。
These hot-rolled sheets were subjected to hot-rolled sheet annealing at 900 ° C. for 60 seconds. At this time, regarding the hot-rolled sheets using the slab of steel symbol XI, 2.5, 3.7, 5.4, 12.7, 23 and 28 ° C
The heating rate was changed to / s, and for the hot-rolled sheet using the slab with the steel symbol V, the heating rate was 12.2 ° C / s.

【0046】その後、これらの焼鈍板を酸洗し、タンデ
ム圧延機により100 〜160 ℃の温度範囲で板厚:0.34mm
に温間圧延したのち、脱脂処理を施し、850 ℃・2分間
の脱炭焼鈍後、0.05%のBを含有するMgO 中に7%の T
iO2 を添加した焼鈍分離剤を塗布してから、昇温時500
℃の温度までをN2 単独の雰囲気、その後、850 ℃の温
度まではN2 :25%、H2 :75%の混合雰囲気、以後H
2 単独の雰囲気で1180℃の温度まで昇温後5時間保持す
る最終仕上げ焼鈍を施したのち、それぞれ未反応焼鈍分
離剤を除去した。
After that, these annealed plates were pickled, and the thickness was 0.34 mm in a temperature range of 100 to 160 ° C. by a tandem rolling mill.
After hot rolling, degreasing treatment was performed, and after decarburization annealing at 850 ° C for 2 minutes, 7% T was added to MgO containing 0.05% B.
After applying the annealing separator containing iO 2 ,
An atmosphere of N 2 alone up to a temperature of ℃, then a mixed atmosphere of N 2 : 25% and H 2 : 75% up to a temperature of 850 ° C, and thereafter H
After subjected to final annealing and holding for 5 hours after heating to a temperature of 1180 ° C. in 2 alone atmosphere to remove unreacted annealing separator, respectively.

【0047】さらに、これらの鋼板に40%のコロイダル
シリカを含有するりん酸マグネシウムを主成分とする絶
縁コーティングを塗布し800 ℃の温度で焼付けそれぞれ
製品とした。
Further, these steel sheets were coated with an insulating coating containing 40% colloidal silica as a main component of magnesium phosphate and baked at a temperature of 800 ° C. to obtain respective products.

【0048】しかるのち、実験1と同様の要領で、未反
応焼鈍分離剤除去後の各鋼板の結晶粒径分布、各製品の
磁気特性および各製品を用いて作製したEIコアの鉄損
などをそれぞれ調査した。これらの調査結果を表5にま
とめて示す。
Then, in the same manner as in Experiment 1, the grain size distribution of each steel sheet after removal of the unreacted annealing separator, the magnetic properties of each product, and the iron loss of the EI core produced using each product were determined. Each was investigated. The results of these investigations are summarized in Table 5.

【0049】[0049]

【表5】 [Table 5]

【0050】表5より、成分組成としてTi,Nb,Bある
いはSbなどがこの発明に適合しないスラブ(鋼記号V)
を素材とした製品板は粒径が1mm以下の微細結晶粒の個
数比率が98%超えて大きく、かつ、磁束密度B8 も1.68
Tと低く、低磁場および高磁場での鉄損はおしなべて劣
悪である。
From Table 5, a slab (steel code V) in which Ti, Nb, B, Sb or the like as a component composition does not conform to the present invention
The product plate made from is large with the number ratio of fine crystal grains of 1 mm or less exceeding 98%, and the magnetic flux density B 8 is 1.68.
It is as low as T, and the iron loss in low and high magnetic fields is generally poor.

【0051】これに対し、Bを微量添加したこの発明に
適合するスラブ(鋼記号XI) を素材とした製品について
は、熱延板焼鈍での昇温速度を5〜25℃/sの範囲とし
た場合に優れた低磁場での鉄損、優れたEIコアでの鉄
損が得られている。昇温速度が上記範囲外の場合にはや
はり粒径が1mm未満の微細結晶粒の個数比率が98%を超
えて増大しており低磁場での鉄損などが劣っている。し
たがって、良好な低磁場特性が得られる条件としては、
粒径が1mm未満の結晶粒の個数比率が一定範囲内にある
ことが必要になる。
On the other hand, in the case of a product made of a slab (steel code XI) conforming to the present invention with a slight amount of B added, the rate of temperature rise during hot-rolled sheet annealing is in the range of 5 to 25 ° C./s. In that case, excellent iron loss in a low magnetic field and excellent iron loss in the EI core were obtained. When the rate of temperature rise is out of the above range, the number ratio of fine crystal grains having a grain size of less than 1 mm increases to more than 98%, and iron loss in a low magnetic field is poor. Therefore, the conditions for obtaining good low magnetic field characteristics are:
It is necessary that the number ratio of crystal grains having a grain size of less than 1 mm is within a certain range.

【0052】かかる結果を得た原因について調査した結
果、熱延板焼鈍の昇温後の析出AlNの分布に大きな差が
あることがわかった。すなわち、良好な磁気特性と結晶
粒分布を得た条件(素材を含む)の熱延板焼鈍の昇温直
後の析出AlN については1.0〜5.0 nmの極めて微細なも
のが高密度に存在していたのに対し、鋼記号Vを素材と
するものや昇温速度が28℃/sと速いものについてはAl
N の析出量が不十分であり、昇温速度が2.5 ℃/sや3.
7 ℃/sと遅いものについては析出AlN が5.0〜20nmと
粗大化していた。このようなインヒビターの析出状態の
違いが2次再結晶に影響を及ぼし製品の結晶組織を変化
させたものと考える。
As a result of investigating the cause of obtaining such a result, it was found that there is a large difference in the distribution of precipitated AlN after the temperature rise of the hot rolled sheet annealing. That is, as for the precipitated AlN immediately after the temperature rising of the hot-rolled sheet annealing under the conditions (including the material) that provided good magnetic properties and crystal grain distribution, extremely fine particles of 1.0 to 5.0 nm existed at high density. On the other hand, for those made of the steel symbol V and those with a high heating rate of 28 ° C / s, Al
The amount of N precipitation is insufficient, and the heating rate is 2.5 ° C / s or 3.
For the slower 7 ° C / s, the precipitated AlN was coarser at 5.0 to 20 nm. It is considered that such a difference in the precipitation state of the inhibitor affects the secondary recrystallization and changes the crystal structure of the product.

【0053】よって、熱延板焼鈍の昇温過程で微細かつ
高密度の状態にAlN の析出制御を行うには昇温速度の制
御が重要で、この速度が遅過ぎる場合はAlN が粗大に析
出し、逆に速度が速過ぎる場合はAlN の析出量が不十分
となる。
Therefore, it is important to control the heating rate in order to control the precipitation of AlN in a fine and high-density state during the heating process of hot-rolled sheet annealing. If this rate is too slow, the AlN precipitates coarsely. On the contrary, if the speed is too fast, the precipitation amount of AlN will be insufficient.

【0054】また、AlN の析出制御のためには昇温速度
の制御のみならず、素材鋼中の微量成分や熱間圧延温度
も重要になる。すなわち、Ti, Nb, BやSbの存在によっ
てAlN の析出核が増加することがわかった。これらのう
ち、Ti, NbおよびBについては、熱間仕上げ圧延におい
て極めて微細な析出物が形成され、これを析出の核とし
て熱延板焼鈍の昇温過程でAlN が析出すること、Sbにつ
いては、結晶粒界にSbが偏析することにより結晶粒界へ
のAlN の粗大析出を抑制し結晶粒内における固溶Alと固
溶Nの実質的濃度を高めてAlN の析出核の生成頻度を高
めることなどがわかった。
For controlling the precipitation of AlN, not only the control of the heating rate but also the trace components in the raw steel and the hot rolling temperature are important. That is, it was found that the presence of Ti, Nb, B and Sb increases AlN precipitation nuclei. Of these, for Ti, Nb and B, extremely fine precipitates are formed during hot finish rolling, and AlN precipitates during the temperature rise process of hot-rolled sheet annealing using these as nuclei for precipitation. , Sb segregates at the grain boundaries to suppress coarse precipitation of AlN at the grain boundaries and increase the substantial concentration of solid solution Al and solid solution N in the crystal grains to increase the frequency of formation of precipitation nuclei of AlN. I understood that.

【0055】このためには、熱間圧延終了温度を970 ℃
以下とすることが必要になる。熱間圧延終了温度が高い
場合は、AlN の析出核となるこれらの極微細析出物すら
析出しなくなり、熱延板焼鈍の昇温過程でのAlN の均一
微細析出ができなくなる。
For this purpose, the hot rolling end temperature is set to 970 ° C.
You will need to: When the hot rolling finish temperature is high, even these ultrafine precipitates that become AlN precipitation nuclei do not precipitate, and uniform fine precipitation of AlN cannot be achieved during the temperature rising process of hot-rolled sheet annealing.

【0056】以上のように、この発明のインヒビター析
出制御は、 1)低Al含有量によるAlN 析出温度の低下とそれに伴う
スラブ加熱温度の低下、 2)AlN 析出核生成成分の微量添加と熱間仕上げ圧延温
度の低温化( 熱間圧延終了温度の上限規制)による析出
核の生成、 3)熱間圧延終了温度の下限規制、熱間圧延終了時から
コイル巻取り時までの冷却速度の下限規制およびコイル
巻取り温度の上限規制による熱間圧延でのAlN 析出の制
御、 4)熱延板焼鈍の昇温速度の制御による昇温過程でのAl
N の微細かつ均一な析出、 5)熱延板焼鈍温度の上限規制によるAlN の再固溶やオ
ストワルド成長による結晶粒の粗大化の抑制、 といったこれまでにない革新的な技術思想とその手段か
らなる。
As described above, the inhibitor precipitation control of the present invention is carried out by 1) decreasing the AlN precipitation temperature due to the low Al content and the accompanying decrease in the slab heating temperature, and 2) adding a small amount of the AlN precipitation nucleation component and performing hot work. Generation of precipitation nuclei by lowering the finish rolling temperature (upper limit of hot rolling end temperature), 3) Lower limit of hot rolling end temperature, lower limit of cooling rate from the end of hot rolling to coil winding And control of AlN precipitation during hot rolling by controlling the upper limit of coil winding temperature, 4) Al in the heating process by controlling the heating rate of hot-rolled sheet annealing
Fine and uniform precipitation of N, 5) Reinforcing solid solution of AlN by controlling the upper limit of annealing temperature of hot rolled sheet, and suppressing coarsening of crystal grains due to Ostwald growth. Become.

【0057】実験3(冷間圧延方法の検討) 良好な結果を得るための冷間圧延技術のもととなった実
験について述べる。前掲表2に示した鋼記号VIIIの成分
組成になるスラブ4本を、前掲表3に示した記号bの条
件で熱間圧延し、それぞれ板厚:2.4 mmの熱延板コイル
とした。このとき、熱間圧延終了時からコイル巻取り時
までの間の冷却速度は17.5℃/sとした。これらの熱延
板に昇温速度を7.8 ℃/sとして900 ℃・30秒間の熱延
板焼鈍を施し、酸洗後、それぞれ板厚:0.34mmに冷間圧
延した。
Experiment 3 (Study of Cold Rolling Method) An experiment which is the basis of the cold rolling technique for obtaining good results will be described. Four slabs having the chemical composition of steel symbol VIII shown in Table 2 above were hot-rolled under the conditions of symbol b shown in Table 3 above to obtain hot rolled sheet coils each having a plate thickness of 2.4 mm. At this time, the cooling rate from the end of hot rolling to the coil winding was 17.5 ° C / s. These hot-rolled sheets were annealed at 900 ° C. for 30 seconds at a heating rate of 7.8 ° C./s, pickled, and then cold-rolled to a sheet thickness of 0.34 mm.

【0058】このとき、第1の焼鈍板はタンデム圧延機
により120 〜180 ℃の温度範囲での温間圧延を施し、第
2の焼鈍板はタンデム圧延機によりクーラントを多量に
被圧延材表面に噴射して50〜80℃の範囲の鋼板温度での
圧延を施し、第3の焼鈍板はリバース式圧延機により圧
延パス間で150 〜220 ℃の温度範囲での時効処理を行っ
て圧延し、第4の焼鈍板はリバース圧延機によりクーラ
ントを多量に被圧延材表面に噴射し50〜80℃の範囲の鋼
板温度での圧延を施した。
At this time, the first annealed plate was subjected to warm rolling in the temperature range of 120 to 180 ° C. by the tandem rolling mill, and the second annealed plate was subjected to a large amount of coolant on the surface of the material to be rolled by the tandem rolling mill. It is jetted and rolled at a steel plate temperature in the range of 50 to 80 ° C., and the third annealed plate is subjected to an aging treatment in the temperature range of 150 to 220 ° C. between rolling passes by a reverse rolling mill and rolled. The fourth annealed plate was subjected to rolling at a steel plate temperature in the range of 50 to 80 ° C. by injecting a large amount of coolant onto the surface of the material to be rolled by a reverse rolling mill.

【0059】その後、各冷延板は脱脂処理後、 850℃・
2分間の脱炭処理を施し、0.05%のBを含有するMgO に
7%のTiO2を添加した焼鈍分離剤を鋼板表面に塗布して
から、昇温時 700℃の温度までをN2 単独の雰囲気、そ
の後、 850℃の温度まではN 2 :25%、H2 :75%の混
合雰囲気、以後H2 単独の雰囲気で1180℃の温度まで昇
温後5時間保持する最終仕上げ焼鈍を施したのち、それ
ぞれ未反応焼鈍分離剤を除去した。
After that, each cold-rolled sheet was degreased at 850 ° C.
It was decarburized for 2 minutes and converted to MgO containing 0.05% B.
7% TiO2Apply the annealing separator with added to the steel plate surface
To 700 ° C when the temperature is raised2Alone atmosphere, that
After that, until the temperature of 850 ℃, N 2: 25%, H2: 75% mixed
Combined atmosphere, then H2Raises the temperature to 1180 ℃ in a single atmosphere
After performing final finishing annealing that keeps for 5 hours after warming,
Each unreacted annealing separator was removed.

【0060】さらに、これらの鋼板に60%のコロイダル
シリカを含有するりん酸マグネシウム主成分とする絶
縁コーティングを塗布し 800℃の温度で焼付けそれぞれ
製品とした。しかるのち、実験1と同様の要領で、未反
応焼鈍分離剤除去後の各鋼板の結晶粒径分布、各製品の
磁気特性および各製品を用いて作製したEIコアの鉄損な
どについてそれぞれ調査した。これらの調査結果を表6
にまとめて示す。
[0060] In addition, the respective baked products at temperatures of applying an insulating coating composed mainly of magnesium phosphate containing 60% colloidal silica in these steel plates 800 ° C.. Then, in the same manner as in Experiment 1, the grain size distribution of each steel sheet after removal of the unreacted annealing separator, the magnetic properties of each product, and the iron loss of the EI core produced using each product were investigated. . Table 6 shows these survey results.
Are shown together.

【0061】[0061]

【表6】 [Table 6]

【0062】表6に示すように、リバース圧延機を用い
た場合に比し、タンデム圧延機を用いて圧延した場合
は、低磁場鉄損W10/50 、高磁場と低磁場との鉄損比 W
10/50/ W17/50 およびEIコアでの鉄損が良好で、特
に 120〜180 ℃の温度範囲で温間圧延した場合は、50〜
80℃の温度範囲で圧延した場合に比しW10/50 は多少高
めであるがW10/50 /W17/50 の値は小さくEIコアの鉄
損にも優れており、また、結晶粒径分布も適切である。
As shown in Table 6, in the case of rolling using the tandem rolling mill, as compared with the case of using the reverse rolling mill, low magnetic field iron loss W 10/50 , iron loss of high magnetic field and low magnetic field Ratio W
Good iron loss at 10/50 / W 17/50 and EI core, especially 50 ~ 50% when warm-rolled in the temperature range of 120-180 ℃.
W 10/50 is slightly higher than that when rolled in the temperature range of 80 ° C, but the value of W 10/50 / W 17/50 is small and it is excellent in iron loss of EI core. The diameter distribution is also appropriate.

【0063】一般に温間圧延や圧延工程での時効処理
は、結晶の圧延変形集合組織を変える働きがあり、圧延
再結晶後の1次再結晶組織中に2次再結晶の核となる
(110)〔001〕方位の結晶粒の生成密度を高める
ことが知られている。このためには、特公昭54−13
846号公報(特性の優れた高磁束密度一方向性珪素鋼
板を得る冷間圧延方法)に開示されているように、従来
はゼンジマ−ミルなどリバース式の圧延機による圧延パ
ス間での時効処理によりCの拡散を図ることが適切とさ
れていた。
Generally, the aging treatment in the warm rolling or rolling process has a function of changing the rolling deformation texture of the crystal, and becomes a nucleus of secondary recrystallization in the primary recrystallization structure after rolling recrystallization (110). ) It is known to increase the production density of crystal grains in the [001] orientation. To this end, Japanese Patent Publication No. 54-13
As disclosed in Japanese Patent No. 846 (cold rolling method for obtaining a high magnetic flux density unidirectional silicon steel sheet having excellent characteristics), conventionally, an aging treatment between rolling passes by a reverse type rolling mill such as a Sendzimer mill. Therefore, it has been considered appropriate to diffuse C.

【0064】しかしながら、この実験結果に示されるよ
うにリバース圧延によるパス間での時効処理は有効でな
く、タンデム圧延機による圧延が有効であった。これら
両者の差異について考察すると、リバース圧延によるパ
ス間時効処理では圧延時の歪速度が相対的に小さく、ま
た圧延パス間に十分時間がありその間に加工歪に起因し
て発生した熱により必然的にCの転位への拡散現象によ
る静的時効が起きるのに対し、タンデム圧延では圧延時
の歪速度が相対的に大きく、また圧延パス間の時間が極
めて短いため静的時効は起こりにくく、圧延パス中、転
位が増殖されつつ同時にCの転位への拡散による動的歪
時効が起こる点にある。
However, as shown in this experimental result, the aging treatment between the passes by the reverse rolling was not effective, but the rolling by the tandem rolling mill was effective. Considering the difference between the two, the strain rate during rolling is relatively small in the inter-pass aging treatment by reverse rolling, and there is sufficient time between rolling passes, which inevitably occurs due to the heat generated due to processing strain during that time. On the other hand, static aging occurs due to the diffusion phenomenon of C to dislocations, whereas in tandem rolling, the strain rate during rolling is relatively high, and the time between rolling passes is extremely short, so static aging does not easily occur. During the pass, dislocations are proliferated and at the same time, dynamic strain aging occurs due to diffusion of C into dislocations.

【0065】この実験結果は、タンデム圧延方式がリバ
ース圧延方式より優れることおよびタンデム圧延におい
て温間圧延は常時圧延に比し優れること、さらには、リ
バース圧延方式ではパス間時効処理が有害なことを示し
ている。したがって、大きい歪速度および動的歪時効は
有効に作用するが、静的時効は有害な作用を及ぼすこと
を示している。
[0065] The results of this experiment, it tandem rolling method having excellent than the warm rolling is always rolled in it and tandem rolling superior reverse rolling method, furthermore, that the path between the aging treatment is detrimental in the reverse rolling system Shows. Thus, high strain rate and dynamic strain aging work effectively, while static aging has a detrimental effect.

【0066】これらのことより、この発明の最終冷間圧
延法としては、タンデム方式が最も優れているといえ
る。さらに、動的歪時効の効果をより向上させるために
は、タンデム圧延方式での圧延温度を90℃以上とするこ
とがよい。
From these, it can be said that the tandem system is the most excellent as the final cold rolling method of the present invention. Furthermore, in order to further improve the effect of dynamic strain aging, the rolling temperature in the tandem rolling system is preferably 90 ° C. or higher.

【0067】実験4(適正なフォルステライト質被膜の
検討) この発明の被膜に関する実験について述べる。前掲表2
に示した鋼記号IXのスラブ9本を、、前掲表3に示した
記号bの条件で熱間圧延し、板厚:2.4mm の熱延板コイ
ルとした。このとき、熱間圧延終了時からコイル巻取り
時までの間の冷却速度は14.5℃/sとした。
Experiment 4 (Study of Appropriate Forsterite Coating) An experiment relating to the coating of the present invention will be described. Table 2 above
Nine slabs of steel symbol IX shown in Table 1 were hot-rolled under the condition of symbol b shown in Table 3 above to obtain a hot-rolled sheet coil having a sheet thickness of 2.4 mm. At this time, the cooling rate from the end of hot rolling to the coil winding was 14.5 ° C / s.

【0068】これらの熱延板に昇温速度を 6.5℃/sと
して 900℃・30秒間の熱延板焼鈍を施し、酸洗後、タン
デム圧延機により 120〜160 ℃の温度範囲で板厚:0.34
mmに温間圧延したのち、脱脂処理し、 850℃・2分間の
脱炭処理をそれぞれ施した。
These hot-rolled sheets were annealed at 900 ° C. for 30 seconds at a temperature rising rate of 6.5 ° C./s, pickled, and then tandem-rolled in a temperature range of 120 to 160 ° C. 0.34
After hot rolling to mm, it was degreased and decarburized at 850 ° C for 2 minutes.

【0069】その後、これらの脱炭処理鋼板に表7に示
す異なる配合の焼鈍分離剤を塗布したのち同じく表7に
示す雰囲気で、1180℃の温度まで30℃/sの昇温速度で
昇温し7時間保持後降温するヒートパターンでそれぞれ
最終仕上げ焼鈍を施したのち、未反応焼鈍分離剤を除去
した。
Thereafter, these decarburized steel sheets were coated with annealing separators having different compositions shown in Table 7, and then heated in the atmosphere shown in Table 7 to a temperature of 1180 ° C. at a heating rate of 30 ° C./s. After performing final finishing annealing in a heat pattern of keeping the temperature for 7 hours and then lowering the temperature, the unreacted annealing separator was removed.

【0070】[0070]

【表7】 [Table 7]

【0071】このとき、鋼板表面には、脱炭焼鈍時に鋼
板表層に生成したSiO2と焼鈍分離剤の主成分であるMgO
が最終仕上げ焼鈍時に反応してフォルステライト(Mg2Si
O4)を主成分とする被膜を形成しているが、これらの鋼
板の被膜中のB,TiおよびAlの含有量を測定した。
At this time, on the surface of the steel sheet, SiO 2 generated in the surface layer of the steel sheet during decarburization annealing and MgO which is the main component of the annealing separator are used.
Reacts during the final annealing and forsterite (Mg 2 Si
Although a coating film containing O 4 ) as a main component is formed, the contents of B, Ti and Al in the coating films of these steel sheets were measured.

【0072】未反応焼鈍分離除去後の各鋼板は、更に60
%のコロイダルシリカを含有するりん酸マグネシウムを
主成分とする絶縁コーティングを塗布し 800℃の温度で
焼付けそれぞれ製品とした。
After the unreacted annealing separation and removal, each steel plate is further 60
% Of colloidal silica was applied as an insulating coating containing magnesium phosphate as a main component, and the product was baked at a temperature of 800 ° C.

【0073】しかるのち、実験1と同様の要領で、未反
応焼鈍分離剤除去後の各鋼板の結晶粒径分布、各製品板
の磁気特性および各製品板を用いて作製したEIコアの鉄
損などについてそれぞれ調査した。これらの調査結果を
表8にまとめて示す。
After that, in the same manner as in Experiment 1, the grain size distribution of each steel sheet after removal of the unreacted annealing separator, the magnetic properties of each product sheet, and the iron loss of the EI core produced using each product sheet were measured. And so on. The results of these investigations are summarized in Table 8.

【0074】[0074]

【表8】 [Table 8]

【0075】表8に示すように、結晶粒径分布はいずれ
もこの発明の適正範囲内にあるが、低磁場での鉄損特性
は、被膜中のAl, TiおよびBの含有量に明らかに依存し
ており、これらの含有量が多いほど鉄損特性は優れてい
る。なお、被膜中のAl, TiおよびBの含有量は、焼鈍分
離剤中のこれらの含有量と最終仕上げ焼鈍雰囲気条件に
よって変化している。
As shown in Table 8, the crystal grain size distributions are all within the proper range of the present invention, but the iron loss characteristics in a low magnetic field clearly show the contents of Al, Ti and B in the coating film. The higher the content, the better the iron loss characteristics. The contents of Al, Ti and B in the coating film vary depending on the contents of these in the annealing separator and the conditions of the final finish annealing atmosphere.

【0076】このように、被膜中のこれらの成分の増加
によって低磁場での鉄損が向上する理由としては、おそ
らくかかる成分が窒化物や酸化物といった形態をとって
存在し、総体としての被膜の熱膨張係数を低下させ、結
果的に張力効果を向上させていることによるものと考え
られる。
As described above, the reason why the iron loss in a low magnetic field is improved by increasing the amount of these components in the coating film is that such components are present in the form of nitride or oxide, and the coating film as a whole is probably present. It is thought that this is due to the fact that the coefficient of thermal expansion is decreased and, as a result, the tension effect is improved.

【0077】最終仕上げ焼鈍における窒素雰囲気は、か
かる被膜中の酸化物や窒化物の形成に重要な働きをして
おり、焼鈍の中期から後期においては特に還元性を強め
ておくことが重要である。
The nitrogen atmosphere in the final finish annealing plays an important role in the formation of oxides and nitrides in the coating film, and it is important to enhance the reducibility especially in the middle to the latter stages of the annealing. .

【0078】すなわち、還元性の強いH2 を雰囲気中に
含有させることによって鋼中窒化物の分解を促進し、被
膜中のAl含有量を増加させることができ、同時に還元性
雰囲気によって被膜形成を促進し、被膜中のTiやB量も
増加させることができる。なお、Alは焼鈍分離剤中に特
に添加しなくとも、鋼中からAlが移行するので、この発
明のように最終仕上げ焼鈍雰囲気を制御して、被膜中へ
のAlの移行を促進し、かつ未反応焼鈍分離剤中へ移行す
るAlを抑制できればよいことになる。
That is, by containing H 2 having a strong reducing property in the atmosphere, the decomposition of the nitride in the steel can be promoted and the Al content in the film can be increased. At the same time, the film formation can be performed in the reducing atmosphere. It can promote and increase the amount of Ti and B in the coating. Incidentally, Al does not need to be particularly added to the annealing separator, since Al migrates from the steel, the final finish annealing atmosphere is controlled as in the present invention to promote the migration of Al into the coating, and It is only necessary to suppress the Al that migrates into the unreacted annealing separator.

【0079】また、鋼中に含有する成分がN2 雰囲気で
施される最終仕上げの冷却過程、絶縁コーティングの焼
付け焼鈍および歪取り焼鈍において重要な作用を有する
ことの知見も得た。すなわち、N2 雰囲気での焼鈍によ
る鋼の窒化の悪影響を、鋼中に存在するTi, BやSbによ
って抑制できる利点がある。TiやBは地鉄と接する被膜
界面に濃縮しBNやTiN を生成し鋼中(地鉄)へのNの侵
入を抑制し被膜強度も高め、Sbは被膜と地鉄との界面に
濃縮して窒化を抑制する作用を有する。
Further, it was also found that the components contained in the steel have important functions in the cooling process of final finishing performed in an N 2 atmosphere, baking annealing and strain relief annealing of the insulating coating. That is, there is an advantage that the adverse effects of nitriding of steel due to annealing in an N 2 atmosphere can be suppressed by Ti, B and Sb existing in the steel. Ti and B are concentrated at the coating interface in contact with the base iron to form BN and TiN, which suppresses the penetration of N into the steel (base iron) and enhances the coating strength. Sb is concentrated at the interface between the coating and the base iron. Has the effect of suppressing nitriding.

【0080】このように、鋼中に存在するTi, BやSb等
の成分は製造工程中の焼鈍のみならず、製品の歪取り焼
鈍においても有利に作用し、被膜の張力強化や地鉄の窒
化抑制に有効な働きをして製品の低磁場鉄損の低減に寄
与していることが、この実験結果を考察することにより
判明した。
As described above, the components such as Ti, B and Sb existing in the steel have an advantageous effect not only in the annealing during the manufacturing process but also in the strain relief annealing of the product, strengthening the tension of the coating and the It was clarified by considering the results of this experiment that it works effectively to suppress nitriding and contributes to the reduction of iron loss in the low magnetic field of the product.

【0081】以上実験1〜4から得られた結果を図1〜
3にまとめて示す。図1は、粒径が1mm未満の結晶粒の
個数比率とEIコアの鉄損および製品の鉄損比W10/50
17/50 との関係を示すグラフである。この図から明ら
かなように粒径が1mm未満の結晶粒の個数比率が25〜98
%の範囲で良好な値が得られている。
The results obtained from the above Experiments 1 to 4 are shown in FIG.
It shows collectively in 3. Figure 1 shows the ratio of the number of crystal grains with a grain size of less than 1 mm, the iron loss of the EI core, and the iron loss ratio of the product W 10/50 /
It is a graph which shows the relationship with W17 / 50 . As is clear from this figure, the number ratio of crystal grains with a grain size of less than 1 mm is 25-98.
Good values are obtained in the range of%.

【0082】図2は、4mm以上、7mm未満の結晶粒の個
数比率および7mm以上の結晶粒の個数比率とEIコアの鉄
損との関係を示すグラフである。この図から明らかなよ
うに、4〜7mmの結晶粒の個数比率が45%を超える場
合、7mm以上の結晶粒の個数比率が10%を超える場合
は、ともにEIコアでの良好な鉄損が得られる可能性はな
い。
FIG. 2 is a graph showing the relationship between the number ratio of crystal grains of 4 mm or more and less than 7 mm and the number ratio of crystal grains of 7 mm or more and the iron loss of the EI core. As is clear from this figure, when the number ratio of crystal grains of 4 to 7 mm exceeds 45% and when the number ratio of crystal grains of 7 mm or more exceeds 10%, good iron loss in the EI core is observed. There is no chance of getting it.

【0083】図3は、種々行った実験の製品のなかで、
結晶粒径分布がこの発明の範囲に適合するものについ
て、フォルステライト質被膜中のAl, TiおよびBの含有
量とEIコアの鉄損との関係を示したグラフである。この
図から明らかなようにAl, TiおよびBの含有量のいずれ
もがこの発明の構成要件を満たしている時のみEIコアで
の優れた鉄損が得られている。
FIG. 3 shows the products of various experiments.
3 is a graph showing the relationship between the content of Al, Ti and B in the forsterite coating and the iron loss of the EI core when the crystal grain size distribution is within the range of the present invention. As is clear from this figure, excellent iron loss in the EI core is obtained only when all of the contents of Al, Ti and B satisfy the constituent requirements of the present invention.

【0084】以上述べてきたような実験と調査をもとに
鋭意研究の結果この発明は完成されたものである。
As a result of earnest research based on the experiments and investigations as described above, the present invention has been completed.

【0085】つぎに、この発明の効果を得るための必須
条件および好適条件とそれらの作用について述べる。ま
ず、この発明の高磁場に比し低磁場での鉄損特性に優れ
る方向性電磁鋼板の構成要件について記す。
Next, the essential and preferred conditions for obtaining the effects of the present invention and their actions will be described. First, the constitutional requirements of the grain-oriented electrical steel sheet of the present invention, which has excellent iron loss characteristics in a low magnetic field as compared with a high magnetic field, will be described.

【0086】この発明の方向性電磁鋼板は下記の成分組
成を必須成分および好適成分として含有させる。
The grain-oriented electrical steel sheet of the present invention contains the following component compositions as essential and preferred components.

【0087】Si:1.5 〜7.0 wt%(以下単に%であらわ
す) Siは、製品の電気抵抗を高め鉄損を低減するのに有効な
成分であり、このためには 1.5%以上含有させるが 7.0
%を超えて含有させると硬度が高くなり製造や加工が困
難になる。したがって、その含有量は 1.5%以上、 7.0
%以下とする。
Si: 1.5 to 7.0 wt% (hereinafter simply expressed as%) Si is an effective component for increasing the electrical resistance of the product and reducing the iron loss.
If it is contained in excess of%, the hardness becomes high and manufacturing and processing become difficult. Therefore, its content is more than 1.5%, 7.0
% Or less.

【0088】Mn:0.3 〜2.5 % Mnは、Siと同じく電気抵抗を高める作用があり、また、
製造時熱間加工を容易にする作用がある。このためには
0.03%以上含有させる必要があるが、2.5 %を超えて含
有させると熱処理時にγ変態を誘起して磁気特性を劣化
させるので、その含有量は0.03%以上、2.5 %以下とす
る。
Mn: 0.3-2.5% Mn has a function of increasing electric resistance like Si, and
It has the function of facilitating hot working during manufacturing. For this
It is necessary to contain 0.03% or more, but if it exceeds 2.5%, γ-transformation is induced during the heat treatment to deteriorate the magnetic properties, so the content should be 0.03% or more and 2.5% or less.

【0089】また、不純物としてCは 0.003%以下、よ
り好ましくは 0.001%以下、SおよびNはともに 0.002
%以下、より好ましくは 0.001%以下に低減することが
必須である。これらの不純物はこの値を超えると磁気特
性上有害な作用があり、特に鉄損を劣化させる。
As impurities, C is 0.003% or less, more preferably 0.001% or less, and both S and N are 0.002%.
% Or less, more preferably 0.001% or less is essential. When these impurities exceed this value, they have a detrimental effect on the magnetic properties and particularly deteriorate iron loss.

【0090】これらの成分のほか必要に応じて下記の成
分を含有させることは可能である。すなわち、インヒビ
ター成分として鋼中に添加するB,Sb, Ge, P, Sn, C
u, Cr, Pb, ZnおよびInや、組織改善のために鋼中に添
加されるMo, NiおよびCoといった成分は2次再結晶を良
好に進行させるために添加されるものであるが、製造後
も製品中に残留する。さらに、TiやBなどの成分の微量
の含有は、被膜と地鉄との界面に窒化物、酸化物を生成
し、低磁場における磁気特性上も有利になる。
In addition to these components, the following components can be contained if necessary. That is, B, Sb, Ge, P, Sn, C added to steel as an inhibitor component
Components such as u, Cr, Pb, Zn and In, and Mo, Ni and Co that are added to the steel to improve the microstructure are added to promote good secondary recrystallization. It remains in the product afterwards. Furthermore, the inclusion of a small amount of components such as Ti and B produces nitrides and oxides at the interface between the coating and the base iron, which is also advantageous in terms of magnetic properties in a low magnetic field.

【0091】ここで、特に、Sbの含有は歪取り焼鈍等の
際に地鉄の窒化抑制効果を有するので好ましく、この目
的のためには、0.0010%以上含有させることが肝要であ
るが、 0.080%を超えて含有させると鋼板の靱性が劣化
し加工が困難となるので、その含有量は0.0010〜0.080
%の範囲が適切である。
Here, in particular, the inclusion of Sb is preferable because it has the effect of suppressing the nitriding of the base iron during stress relief annealing, and for this purpose, it is essential to contain 0.0010% or more. %, The toughness of the steel sheet deteriorates and it becomes difficult to process. Therefore, the content is 0.0010 to 0.080.
The appropriate range is%.

【0092】かかる方向性電磁鋼板の表面は絶縁物を存
在させた状態で使用され、最終仕上げ焼鈍時に形成され
るフォルステライト(Mg2SiO4) を主成分とする絶縁被膜
が用いられるが、この絶縁被膜の上にさらに上塗りコー
ティングを被成させてもよい。
The surface of such a grain-oriented electrical steel sheet is used in the presence of an insulating material, and an insulating coating containing forsterite (Mg 2 SiO 4 ) as a main component formed during final finishing annealing is used. A topcoat may also be applied over the insulating coating.

【0093】さらに、このフォルステライト質被膜中の
微量成分を制御することが、この発明の必須構成要件の
ひとつである。すなわち、被膜中にAl, TiおよびBを含
有させることが必要である。これらの成分を含有させる
ことにより、被膜の張力効果が高まり製品の低磁場領域
での鉄損が向上する。この効果を得るためには、Al:0.
5 %以上、Ti:0.1 %以上およびB:0.01%以上の含有
が必要である。しかし、Al:15%超え、Ti:10%超えお
よびB:0.8 %超えの過剰な量の含有は、被膜の硬度を
過度に増加し逆に被膜の密着性を劣化させるので不適で
ある。よって、Al:0.5 〜15%、Ti:0.1 〜10%および
B:0.01〜0.8 %の範囲で被膜中に含有させることが必
要である。
Further, controlling the trace components in the forsterite coating is one of the essential constituents of the present invention. That is, it is necessary to include Al, Ti and B in the coating. By including these components, the tension effect of the coating is enhanced and the iron loss in the low magnetic field region of the product is improved. To obtain this effect, Al: 0.
It is necessary to contain 5% or more, Ti: 0.1% or more and B: 0.01% or more. However, the inclusion of excessive amounts of Al: more than 15%, Ti: more than 10% and B: more than 0.8% is not suitable because the hardness of the coating is excessively increased and the adhesion of the coating is deteriorated. Therefore, it is necessary to contain Al: 0.5 to 15%, Ti: 0.1 to 10% and B: 0.01 to 0.8% in the coating film.

【0094】ここで、被膜中のこれらの成分の濃度測定
法について記す。鋼板表面にフォルステライト質被膜の
みが存在する状態にして、鋼板の酸素含有量 (fO) 、Al
含有量 (fAl)、Ti含有量(fTi)およびB含有量(fB) を
分析し、つづいて、フォルステライト質被膜を 酸洗に
より除去したのち、再び鋼板の酸素含有量 (sO) 、Al含
有量 (sAl)、Ti含有量 (sTi)およびB含有量 (sB) を分
析する。かくして、フォルステライト質被膜量はほぼ、
f=(fO-sO)×Mg2SiO4 ÷04 = (fO-sO)×140.6 ÷64
の式で算出できるので、 被膜中のAl含有量は (fAl-sAl)÷f×100 (%) 被膜中のTi含有量は (fTi-sTi)÷f×100 (%) 被膜中のB含有量は (fB-sB)÷f×100 (%) で、それぞれ算出できる。
Here, the method for measuring the concentrations of these components in the coating will be described. The oxygen content (fO) of the steel sheet, Al
The content (fAl), Ti content (fTi) and B content (fB) were analyzed, and then the forsterite coating was removed by pickling, and then the oxygen content (sO) and Al content of the steel sheet were again detected. The amount (sAl), Ti content (sTi) and B content (sB) are analyzed. Thus, the amount of forsterite coating is almost
f = (fO-sO) × Mg 2 SiO 4 ÷ 0 4 = (fO-sO) × 140.6 ÷ 64
As the Al content in the coating is (fAl-sAl) ÷ f × 100 (%), the Ti content in the coating is (fTi-sTi) ÷ f × 100 (%) B content in the coating The amount can be calculated by (fB-sB) ÷ f × 100 (%).

【0095】ついで、この発明の方向性電磁鋼板を構成
する結晶粒についての各必須要件とその作用について記
述する。
Next, each essential requirement for the crystal grains constituting the grain-oriented electrical steel sheet of the present invention and its action will be described.

【0096】この発明の方向性電磁鋼板において対象と
する結晶粒は、板厚方向に貫通しているものを対象とす
る。そして、結晶粒の粒径とは鋼板表面における結晶粒
の面積と同一の面積を有する円の直径(円相当径)をも
ってあらわし、平均結晶粒径は、一定面積中に含まれる
結晶粒の個数で該面積を除し、この値の円相当径をもっ
て平均結晶粒径とする。
In the grain-oriented electrical steel sheet of the present invention, the target crystal grains are those penetrating in the plate thickness direction. The grain size of the crystal grain is represented by the diameter of a circle having the same area as the area of the crystal grain on the surface of the steel sheet (equivalent circle diameter), and the average grain size is the number of crystal grains contained in a certain area. The area is divided, and the equivalent circle diameter of this value is taken as the average crystal grain size.

【0097】このような結晶粒の鋼板面内方向の結晶粒
径として1mm未満の結晶粒の個数比率が25〜98%、4mm
以上、7mm未満の結晶粒の個数比率が45%以下および7
mm以上の結晶粒の個数比率が10%以下であることが必要
である。
The ratio of the number of crystal grains having a grain size in the in-plane direction of the steel sheet of less than 1 mm is 25 to 98%, 4 mm
As a result, the number ratio of crystal grains of less than 7 mm is 45% or less and 7
It is necessary that the number ratio of crystal grains of mm or more is 10% or less.

【0098】7mm以上の結晶粒は高磁場に比し低磁場で
の鉄損を増加させる作用があり、実機特性の向上のため
には10%以下の個数比率に抑制し、同様に4mm以上、7
mm未満の結晶粒の個数比率を45%以下に抑制することが
必須である。4mm未満の結晶粒の個数比率、特に1mm未
満の結晶粒の個数比率を増加させることが低磁場での鉄
損の向上に極めて有効で、1mm未満の結晶粒の個数比率
は25%以上とすることが必要であるが、98%を超えると
逆に低磁場での鉄損が増大し実機特性の劣化をもたらす
ので、その上限は98%とする。
A crystal grain of 7 mm or more has an effect of increasing iron loss in a low magnetic field as compared with a high magnetic field, and in order to improve the characteristics of an actual machine, it is suppressed to a number ratio of 10% or less. 7
It is essential to suppress the number ratio of crystal grains less than mm to 45% or less. Increasing the number ratio of crystal grains of less than 4 mm, especially the number ratio of crystal grains of less than 1 mm is extremely effective in improving iron loss in a low magnetic field, and the number ratio of crystal grains of less than 1 mm should be 25% or more. However, if it exceeds 98%, the iron loss in a low magnetic field increases conversely, resulting in deterioration of actual machine characteristics, so the upper limit is made 98%.

【0099】高磁場での鉄損を増大し低磁場での鉄損を
低減して実機特性の向上をはかるためには、このように
結晶粒径を極微細化し一定範囲内に揃えることが肝要
で、4mm未満の結晶粒、特に1mm未満の結晶粒を増加さ
せることが必須の技術となる。
In order to increase the iron loss in the high magnetic field and reduce the iron loss in the low magnetic field to improve the characteristics of the actual machine, it is important to make the crystal grain size extremely fine and align it within a certain range. Therefore, increasing the number of crystal grains of less than 4 mm, especially less than 1 mm is an essential technique.

【0100】こうした結晶粒の制御と併せて、前記した
被膜中のAl, TiおよびBの含有量の調整により、高磁場
に比し低磁場での鉄損特性に優れる製品とすることが可
能となる。
By adjusting the contents of Al, Ti and B in the coating film together with the control of the crystal grains, it is possible to obtain a product having excellent iron loss characteristics in a low magnetic field as compared with a high magnetic field. Become.

【0101】つぎに、この発明の高磁場に比し低磁場で
の鉄損特性に優れる方向性電磁鋼板の製造方法の構成要
件として、限定条件、好適条件とその理由について述べ
る。まず、素材の成分組成について述べる。
Next, limiting conditions, preferable conditions and the reasons therefor will be described as constituents of the method for producing a grain-oriented electrical steel sheet of the present invention which is excellent in iron loss characteristics in a low magnetic field as compared with a high magnetic field. First, the composition of ingredients will be described.

【0102】C:0.005 〜0.070 % Cは、含有量を 0.070%以下とすることをこの発明の特
徴とする。すなわち、0.070 %を超えるとγ変態量が過
剰となり、熱間圧延中のAlの分布が不均一になり、熱延
板焼鈍の昇温過程で析出するAlN の分布も不均一となり
低磁場における良好な磁気特性が得られなくなる。一
方、含有量が 0.005%未満では組織の改善効果が得られ
ず2次再結晶が不完全となり同じく磁気特性が劣化す
る。したがって、その含有量は 0.005〜0.070 %の範囲
に限定する。
C: 0.005-0.070% C is a feature of the present invention in that the content of C is 0.070% or less. That is, if it exceeds 0.070%, the amount of γ-transformation becomes excessive, the distribution of Al during hot rolling becomes non-uniform, and the distribution of AlN precipitated during the temperature rising process of hot-rolled sheet annealing becomes non-uniform and good at low magnetic fields. Magnetic properties cannot be obtained. On the other hand, if the content is less than 0.005%, the effect of improving the structure cannot be obtained, and the secondary recrystallization becomes incomplete, and the magnetic properties also deteriorate. Therefore, its content is limited to the range of 0.005 to 0.070%.

【0103】Si:1.5 〜7.0 % Siは、電気抵抗を増加させ鉄損を低減するために必須の
成分であり、このためには 1.5%以上含有させることが
必要であるが、7.0 %を超えて含有させると加工性が劣
化し製造や製品の加工が極めて困難になる。したがっ
て、その含有量は1.5 〜7.0 %の範囲とする。
Si: 1.5-7.0% Si is an essential component for increasing electric resistance and reducing iron loss. For this purpose, it is necessary to contain 1.5% or more, but more than 7.0%. If it is contained as a component, the workability is deteriorated and it becomes extremely difficult to manufacture or process the product. Therefore, its content should be in the range of 1.5 to 7.0%.

【0104】Mn:0.03〜2.5 % Mnは、Siと同じく電気抵抗を高め、また、製造時の熱間
加工性を向上させるので必要な成分である。このために
は、0.03%以上含有させることが必要であるが、2.5 %
を超えて含有させるとγ変態を誘起して磁気特性が劣化
するので、その含有量は0.03〜2.5 %の範囲とする。
Mn: 0.03 to 2.5% Mn is a necessary component because it raises the electrical resistance like Si and improves the hot workability during manufacturing. For this purpose, it is necessary to contain 0.03% or more, but 2.5%
If it is contained in excess of 0.1%, γ-transformation is induced and the magnetic properties are deteriorated, so the content is made 0.03 to 2.5%.

【0105】素材の鋼中にはこれらの成分のほかに良好
な2次再結晶を誘起させるためのインヒビター成分を含
有させることが必要で、AlおよびNを含有させることを
必須とする。
In addition to these components, it is necessary to contain an inhibitor component for inducing good secondary recrystallization in the material steel, and it is essential to contain Al and N.

【0106】Al: 0.005〜0.017 %、N:0.0030〜0.01
00% Alは、含有量が 0.005%未満では熱延板焼鈍の昇温過程
で析出するAlN の量が不足する。逆に、0.017 %を超え
ると1200℃の温度前後でのスラブの低温加熱において A
lNの固溶が困難となり、また、AlN の固溶温度が上昇す
るため、熱間圧延工程でAlN が析出してしまい、この発
明の特徴の一つである熱延板焼鈍の昇温過程でのAlN の
微細析出が不能となり、低磁場での良好な鉄損特性が得
られなくなる。なお、この不備を解消するため1400℃の
温度前後の高温でスラブ加熱を行うと、製品の結晶粒径
が粗大化して高磁場での鉄損が低減し低磁場での鉄損が
増大する結果となり、実機での鉄損が劣化する。したが
って、Alは0.005 〜0.017%の範囲で含有させることが
必要である。
Al: 0.005-0.017%, N: 0.0030-0.01
If the content of 00% Al is less than 0.005%, the amount of AlN precipitated during the temperature rising process of hot-rolled sheet annealing is insufficient. On the other hand, if it exceeds 0.017%, it will be
Since solid solution of lN becomes difficult and the solid solution temperature of AlN rises, AlN precipitates in the hot rolling process, which is one of the features of this invention in the temperature rising process of hot-rolled sheet annealing. As a result, fine precipitation of AlN becomes impossible and good iron loss characteristics cannot be obtained in a low magnetic field. If slab heating is performed at a high temperature around 1400 ° C in order to eliminate this deficiency, the crystal grain size of the product becomes coarser, the iron loss in the high magnetic field decreases, and the iron loss in the low magnetic field increases. And the iron loss in the actual machine deteriorates. Therefore, it is necessary to contain Al in the range of 0.005 to 0.017%.

【0107】一方Nは、AlN を構成する成分であるの
で、0.0030%以上含有させることが必要である。しかし
ながら、0.0100%を超えて含有させると鋼中でガス化し
ふくれなどの欠陥をもたらすので、その含有量は0.0030
〜0.0100%の範囲とする。さらに、この発明では、Ti,
Nb, BまたはSbのうちから選ばれる1種または2種以上
を含有させることが必須の構成要件となる。
On the other hand, N is a component constituting AlN, so it is necessary to contain 0.0030% or more. However, if the content exceeds 0.0100%, it is gasified in the steel and causes defects such as blistering, so its content is 0.0030%.
The range is to 0.0100%. Furthermore, in this invention, Ti,
It is essential to include one or more selected from Nb, B or Sb.

【0108】これらの成分は、熱間圧延において微細な
析出物を形成し、次工程の熱延板焼鈍の昇温過程におけ
るAlN の析出核を増加させる作用を有するものである。
かかる作用効果を得るためのそれぞれの含有量として
は、Ti:0.0005%以上、Nb:0.0010%以上、B:0.0001
%以上およびSb:0.0010%%以上を必要とする。しか
し、Ti:0.0020%超え、Nb:0.010 %超え、B:0.0020
%超えおよびSb:0.080 %超えで含有した場合には製品
のベンド特性など機械的特性が劣化する。したがってこ
れらの含有量はそれぞれ、Tiは0.0005〜0.0020%の範
囲、Nbは0.0010〜0.010 %の範囲、Bは0.0001〜0.0020
%の範囲およびSbは0.0010〜0.080 %の範囲とする。
These components have a function of forming fine precipitates in the hot rolling and increasing AlN precipitation nuclei in the temperature rising process of the hot rolling annealing in the next step.
The respective contents for obtaining such action and effect are as follows: Ti: 0.0005% or more, Nb: 0.0010% or more, B: 0.0001
% And Sb: 0.0010 %% or more is required. However, Ti: 0.0020% over, Nb: 0.010% over, B: 0.0020
% And Sb: If contained in excess of 0.080%, mechanical properties such as bend properties of the product will deteriorate. Therefore, the contents of Ti are 0.0005 to 0.0020%, Nb is 0.0010 to 0.010%, and B is 0.0001 to 0.0020%.
% And Sb are in the range of 0.0010 to 0.080%.

【0109】その他の添加成分については、高磁場に比
し低磁場での鉄損特性の良好な方向性電磁鋼板を得るた
めに必ずしも必要とされるものではないが、例えばMoの
添加などは鋼板の表面性状を改善する効果があるので含
有させることはよく、また、BiやTeなどを適宜含有させ
ることも可能である。
Other additional components are not necessarily required to obtain a grain-oriented electrical steel sheet having a good iron loss characteristic in a low magnetic field as compared with a high magnetic field. Since it has the effect of improving the surface properties of the above, it is preferable to contain it, and it is also possible to appropriately contain Bi, Te and the like.

【0110】つづいて、製造工程条件について記す。常
法により上記の成分組成に調整された鋼は、通常スラブ
加熱に供されたのち熱間圧延により熱延板コイルとされ
るが、このスラブ加熱温度を1250℃以下の温度にするこ
とがこの発明の重要な構成要件である。すなわち、高温
でスラブ加熱を行った場合、製品での結晶粒の分布につ
き、7mm以上の粗大な結晶粒の比率が増大し、低磁場で
の鉄損が増大する。このようなことから良好な結晶粒分
布と磁気特性を得るためにはスラブ加熱温度は1250℃以
下の温度となる。さらに、近年、スラブ加熱を行わずに
連続鋳造後、直接熱間圧延を行う方法が開発されている
が、この方法はスラブ温度がほとんど上昇しないので、
当然のこととしてこの発明の方向性電磁鋼板の製造方法
として適した方法である。
Next, the manufacturing process conditions will be described. Steel adjusted to the above component composition by a conventional method is usually hot-rolled sheet coil by hot rolling after being subjected to slab heating, this slab heating temperature can be 1250 ℃ or less It is an important constituent of the invention. That is, when slab heating is performed at a high temperature, the ratio of coarse crystal grains of 7 mm or more increases in the distribution of crystal grains in the product, and iron loss in a low magnetic field increases. From the above, the slab heating temperature is 1250 ° C or lower in order to obtain good grain distribution and magnetic properties. Furthermore, in recent years, a method of directly hot rolling after continuous casting without performing slab heating has been developed, but since the slab temperature hardly rises in this method,
As a matter of course, the method is suitable as a method for manufacturing the grain-oriented electrical steel sheet of the present invention.

【0111】熱間圧延においては熱間圧延終了温度を 8
00〜970 ℃の範囲にすることが必須の条件である。熱間
圧延終了温度が 800℃未満である場合、鋼中にAlN が析
出し磁気特性の劣化をもたらし、逆に、970 ℃の温度を
超える場合は鋼中にAlN 析出のための核生成サイトとな
る析出物の生成量と分布が不充分となり磁気特性が劣化
する。
In the hot rolling, the hot rolling end temperature is set to 8
It is an essential condition that the temperature is in the range of 00 to 970 ° C. When the hot rolling finish temperature is lower than 800 ° C, AlN precipitates in the steel and causes deterioration of magnetic properties. Conversely, when the temperature exceeds 970 ° C, nucleation sites for AlN precipitation are formed in the steel. The amount and distribution of these precipitates become insufficient and the magnetic properties deteriorate.

【0112】熱間圧延終了後は10℃/s以上の冷却速度
で冷却することが必要である。これは、10℃/s未満の
冷却速度では、冷却中にAlN が析出し磁気特性が劣化す
ることによる。さらにコイル巻取り温度を 670℃以下の
温度に制御することが必須となる。これもまた、巻取り
温度が 670℃を超える場合はやはりAlN が析出し磁気特
性の劣化を招くことによる。
After completion of hot rolling, it is necessary to cool at a cooling rate of 10 ° C./s or more. This is because at a cooling rate of less than 10 ° C / s, AlN precipitates during cooling and the magnetic properties deteriorate. Furthermore, it is essential to control the coil winding temperature to 670 ° C or lower. This is also because when the coiling temperature exceeds 670 ° C, AlN precipitates and deteriorates the magnetic properties.

【0113】かかる制御によって、熱間圧延でのAlN の
析出を抑制した熱延板コイルに、熱延板焼鈍を施すが、
この熱延板焼鈍を極めて低温で行うことがこの発明の独
創的なところである。この熱延板焼鈍の温度と時間の適
合条件は、800 〜950 ℃の温度範囲で保持時間 100秒間
以内とすることである。すなわち、熱延板焼鈍温度が95
0 ℃を超える場合や焼鈍時間が 100秒間を超える場合に
は、冷間圧延前鋼板の結晶粒が粗大化し、結果として1
次再結晶粒径が増大するため2次再結晶不良となり、熱
延板焼鈍温度が 800℃未満の場合は昇温過程における A
lNが析出が不十分となる。
By the above control, the hot rolled sheet coil in which precipitation of AlN in the hot rolling is suppressed is subjected to hot rolled sheet annealing.
It is the originality of this invention that this hot-rolled sheet annealing is performed at an extremely low temperature. The temperature and time compatibility conditions for this hot-rolled sheet annealing are that the holding time is within 100 seconds in the temperature range of 800 to 950 ° C. That is, the hot-rolled sheet annealing temperature is 95
If the temperature exceeds 0 ° C or if the annealing time exceeds 100 seconds, the grain size of the steel sheet before cold rolling becomes coarse, resulting in 1
If the annealing temperature of the hot-rolled sheet is less than 800 ℃, the A
lN becomes insufficiently precipitated.

【0114】さらにこの熱延板の昇温過程でAlN を析出
させる点がこの発明の最も新しい技術であるが、かかる
焼鈍の昇温速度を5〜25℃/sの範囲に制御することも
必須の条件となる。すなわち、これは、昇温速度が5℃
/s未満の場合はAlN が粗大に析出して磁気特性の劣化
を招き、逆に25℃/sを超える場合はAlN の析出量が不
十分となり、同様に磁気特性の劣化を招くからである。
Furthermore, the point that AlN is precipitated during the temperature rising process of this hot rolled sheet is the newest technology of the present invention, but it is also essential to control the temperature rising rate of such annealing within the range of 5 to 25 ° C / s. It becomes the condition of. That is, this is because the heating rate is 5 ° C.
If it is less than / s, AlN coarsely precipitates and causes deterioration of magnetic properties. On the other hand, if it exceeds 25 ° C / s, the amount of AlN precipitates becomes insufficient and similarly deteriorates magnetic properties. .

【0115】熱延焼鈍後は、1回の冷間圧延によって最
終冷延板厚とされるが、このときタンデム圧延機による
冷間圧延とすることが必須の条件となる。
After the hot rolling annealing, the final cold rolled sheet thickness is obtained by one cold rolling. At this time, cold rolling by a tandem rolling mill is an essential condition.

【0116】ここで、タンデム圧延機とは、ロール対の
間を通板し圧延する圧延機を通板方向に連続配設し、鋼
板の一方向通板に対し連続して圧延することを可能とし
たものをいう。
[0116] Here, the tandem rolling mill is a rolling mill for rolling by rolling between a pair of rolls, which is continuously arranged in the rolling direction, and is capable of rolling continuously on one direction of rolling. It means that.

【0117】かかるタンデム圧延機での圧延によって圧
延パス間における有害な静的時効を抑制することが可能
であるとともに歪速度を増大させ良好な圧延集合組織を
得ることが可能となる。すなわち、これにより1次再結
晶集合組織が2次再結晶の粒成長を促進する方向へと改
善され、微細結晶粒の核生成と成長を促進し、製品での
1mm未満の粒径の結晶粒や1〜4mmの粒径の結晶粒の安
定した発生を促す。この際、圧延中の鋼板温度を高める
ことによって動的歪時効をじゃっ起し、さらに好ましい
効果を得ることも可能である。このための圧延温度とし
ては鋼板の温度で90〜300 ℃の範囲が適切である。
By rolling with such a tandem rolling mill, it is possible to suppress harmful static aging between rolling passes, and increase the strain rate to obtain a good rolling texture. That is, by this, the primary recrystallization texture is improved in the direction of promoting the secondary recrystallization grain growth, promoting the nucleation and growth of fine crystal grains, and the grain size of the product is less than 1 mm. Promotes stable generation of crystal grains with a grain size of 1 to 4 mm. At this time, by raising the temperature of the steel sheet during rolling, it is possible to induce dynamic strain aging and obtain a more preferable effect. A suitable rolling temperature for this purpose is a steel sheet temperature in the range of 90 to 300 ° C.

【0118】ゼンジマー圧延機などのリバース方式の圧
延の場合、必然的に静的時効を伴い、2次再結晶粒の成
長性に劣る1次再結晶組織が生成して1mm未満の結晶粒
の個数比率が過度に増大し、製品での鉄損を高磁場鉄損
のみならず低磁場鉄損をも劣化させ、実機での鉄損特性
が不良となる。
In the case of reverse rolling such as a Zenzimer rolling mill, static aging is inevitably accompanied, and a primary recrystallized structure which is inferior in the growth property of secondary recrystallized grains is formed and the number of crystal grains less than 1 mm. If the ratio is excessively increased, the iron loss in the product is deteriorated not only in the high magnetic field iron loss but also in the low magnetic field iron loss, and the iron loss characteristic in the actual machine becomes poor.

【0119】さらに、かかる冷間圧延の圧下率を80〜95
%とする。これは、圧下率が80%未満の場合、製品の1
mm未満の結晶粒の個数比率が低減し、高磁場鉄損の低減
の割に低磁場鉄損が増大して実機での鉄損特性が不良と
なり、逆に圧下率が95%を超える場合は製品の1mm未満
の結晶粒の個数比率が過大となり、低磁場鉄損が増大
し、やはり実機での鉄損特性が不良となるからである。
Further, the reduction ratio of the cold rolling is 80 to 95.
%. This is one of the products when the rolling reduction is less than 80%.
When the ratio of the number of crystal grains less than mm is reduced and the high magnetic field iron loss is reduced, the low magnetic field iron loss increases and the iron loss characteristics in the actual machine become poor. Conversely, when the rolling reduction exceeds 95%, This is because the ratio of the number of crystal grains of less than 1 mm in the product becomes excessively large, the low magnetic field iron loss increases, and the iron loss characteristics in the actual machine also become poor.

【0120】冷間圧延後は、1次再結晶焼鈍を施し、そ
の後Ti化合物を1〜20%およびBを0.04〜1.0 %含有す
る焼鈍分離剤を塗布してから、昇温途中の少なくとも 8
50℃以上の温度からはH2 を含有する雰囲気で最終仕上
げ焼鈍を施す。ここで、1次再結晶焼鈍時および最終仕
上げ焼鈍時の鋼板の窒化は極力抑制することが重要であ
る。
After cold rolling, primary recrystallization annealing was performed, and then an annealing separator containing 1 to 20% of Ti compound and 0.04 to 1.0% of B was applied.
From the temperature of 50 ° C. or higher, final finish annealing is performed in an atmosphere containing H 2 . Here, it is important to suppress nitriding of the steel sheet during primary recrystallization annealing and final finish annealing as much as possible.

【0121】焼鈍分離剤中にTi化合物およびBを含有さ
せ、最終仕上げ焼鈍の昇温途中の少なくとも 850℃以上
の温度からH2 を含有する雰囲気を用いる理由は、これ
によって、AlN の分解を促進したり、最終仕上げ焼鈍後
に形成されるフォルステライト質被膜中のTiやBの含有
量を増加させ、被膜の張力効果を高めて低磁場領域にお
ける鉄損を向上させるためである。
The reason why an atmosphere containing H 2 from a temperature of at least 850 ° C. or higher during the temperature rising of the final finish annealing is used because of the inclusion of the Ti compound and B in the annealing separator is to accelerate the decomposition of AlN. Or for increasing the Ti and B contents in the forsterite coating formed after the final finish annealing to enhance the tension effect of the coating and improve the iron loss in the low magnetic field region.

【0122】このためには、Ti化合物を1%以上、Bを
0.04%以上含有させる必要がある。すなわち、これらの
値未満の場合、最終仕上げ焼鈍昇温途中の雰囲気制御に
よっても被膜中に含有せしめるTiやB量が不足し、所期
の磁気特性が得られなくなり、逆にTi化合物が20%超え
およびBが1.0 %超えで含有する場合は、被膜の硬度が
過度に高まり、被膜の密着性が劣化する。
For this purpose, 1% or more of the Ti compound and B are added.
It is necessary to contain 0.04% or more. That is, when the amount is less than these values, the amount of Ti and B contained in the coating is insufficient even by controlling the atmosphere during the temperature increase in final finish annealing, and the desired magnetic properties cannot be obtained. When the content of B exceeds 1.0% and the content of B exceeds 1.0%, the hardness of the coating is excessively increased and the adhesion of the coating is deteriorated.

【0123】さらに、最終仕上げ焼鈍の昇温途中で850
℃の温度を超えてN2単味の雰囲気で焼鈍を行った場合、
AlN の分解が遅滞し地鉄から被膜へのAlの速やかな移行
がなされず、また、被膜形成反応も遅滞し、被膜中への
TiやBの濃化が起きず、所定の磁気特性が得られなくな
る。
Further, during the temperature rising of the final finish annealing, 850
When annealing is performed in an atmosphere of N 2 above the temperature of ℃,
Decomposition of AlN is delayed, Al is not rapidly transferred from the base steel to the film, and the film formation reaction is also delayed, and
The concentration of Ti and B does not occur, and the desired magnetic characteristics cannot be obtained.

【0124】最終仕上げ焼鈍後は、必要に応じて絶縁コ
ーティングを塗布・焼付け、さらに平坦化焼鈍を施し製
品とする。
After the final finish annealing, an insulating coating is applied and baked if necessary, and further flattening annealing is performed to obtain a product.

【0125】[0125]

【実施例】【Example】

実施例1 前掲表2に示した鋼記号IからXVまでの成分組成の溶鋼
を電磁攪拌を行いながら連続鋳造してスラブとなし、各
1 本ずつを前掲表3 に示した条件で熱間圧延し、それぞ
れ2.4 mmの厚みの熱延板コイルとした。また、熱間圧延
終了時からコイル巻取りまでの間の冷却速度としては1
5.3〜18.6℃/sの急冷とした。この後これらのコイル
は全て2分割し、一方は900 ℃の温度で60秒間、他方は
1050℃の温度で60秒間の熱延板焼鈍を施した。さらに、
これらのコイルは酸洗後150 ℃の温度でタンデム圧延機
によってそれぞれ0.34mmの厚みに圧延した。
Example 1 Molten steel having the composition of steel symbols I to XV shown in Table 2 above was continuously cast into a slab while electromagnetic stirring was performed.
Each piece was hot-rolled under the conditions shown in Table 3 above to form hot-rolled sheet coils each having a thickness of 2.4 mm. The cooling rate from the end of hot rolling to the coil winding is 1
The cooling rate was 5.3 to 18.6 ° C / s. After this, these coils were all divided into two, one at a temperature of 900 ° C for 60 seconds and the other
The hot-rolled sheet was annealed at a temperature of 1050 ° C for 60 seconds. further,
Each of these coils was pickled and then rolled at a temperature of 150 ° C by a tandem rolling mill to a thickness of 0.34 mm.

【0126】その後、脱脂処理を行い850 ℃の温度で2
分間の脱炭焼鈍を施し、0.12%のBを含有するMgO 中に
7%のTiO2を添加した焼鈍分離剤を鋼板表面に塗布し、
昇温時500 ℃の温度までN2 単独の雰囲気、つづいて10
50℃の温度までをN2 :25%、H2 :75%の混合雰囲
気、以後H2 単独雰囲気で1200℃の温度まで昇温後5時
間保持する最終仕上げ焼鈍を施したのち、未反応焼鈍分
離剤をそれぞれ除去した。これらのコイルはさらに40%
のコロイダルシリカを含有するりん酸マグネシウムを主
成分とする絶縁コーティングを塗布し800 ℃の温度で焼
付けそれぞれ製品とした。
After that, degreasing treatment is performed at a temperature of 850 ° C. for 2 hours.
Decarburization annealing for 1 minute, apply the annealing separator with 7% TiO 2 in MgO containing 0.12% B,
At the time of heating up to a temperature of 500 ° C, an atmosphere of N 2 alone, then 10
After a final atmosphere of up to 50 ° C mixed atmosphere of N 2 : 25% and H 2 : 75%, and then a temperature of 1200 ° C for 5 hours in a single atmosphere of H 2 and then a final finishing annealing, unreacted annealing Each separating agent was removed. 40% more for these coils
An insulating coating containing magnesium phosphate as a main component containing colloidal silica was applied and baked at a temperature of 800 ° C to obtain each product.

【0127】しかるのち、未反応焼鈍分離剤を除去した
各鋼板についてフォルステライト質被膜中の、Al:Tiお
よびBの含有量を分析し、鋼板をマクロエッチし結晶粒
径の分布をそれぞれ測定した。また各製品より圧延方向
に沿ってエプスタインサイズの試験片を切り出し800 ℃
の温度で3時間の歪取焼鈍を施したのち、1.0 Tおよび
1.7 Tの磁束密度における鉄損の値 W10/50 、 W17/50
および磁束密度B8 をそれぞれ測定した。さらに、各製
品からEIコア用の鉄芯を打抜き、歪取焼鈍を施し積み
加工、銅線の巻加工などによってEIコアそれぞれ作製
しこれらのEIコアの鉄損特性についても調査した。こ
れらの調査結果を表9にまとめて示す。
Then, the content of Al: Ti and B in the forsterite coating of each steel sheet from which the unreacted annealing separator was removed was analyzed, and the steel sheet was macro-etched to measure the distribution of crystal grain size. . Epstein-sized test pieces were cut from each product along the rolling direction at 800 ° C.
After performing stress relief annealing for 3 hours at the temperature of 1.0T and
Iron loss values at magnetic flux density of 1.7 T W 10/50 , W 17/50
And the magnetic flux density B 8 were measured. Further, iron cores for EI cores were punched out from each product, strain relief annealing was performed, stacking work, copper wire winding work, etc. were respectively made, and the iron loss characteristics of these EI cores were also investigated. The results of these investigations are summarized in Table 9.

【0128】[0128]

【表9】 [Table 9]

【0129】表9に示すようにこの発明に適合する方向
性電磁鋼板は高磁場特性に比較して低磁場での鉄損特性
に優れ、実機での鉄損が極めて良好である。
As shown in Table 9, the grain-oriented electrical steel sheet conforming to the present invention is superior to the high magnetic field characteristic in the iron loss characteristic in the low magnetic field, and the iron loss in the actual machine is very good.

【0130】実施例2 前掲表2に示した鋼記号XII の成分組成の溶鋼を電磁攪
拌を行いながら連続鋳造機で鋳込みスラブとなし、該ス
ラブ6本を前掲表3の記号bに示した条件で熱間圧延
し、それぞれ2.2 mmの厚みの熱延板コイルとした。この
時熱間圧延終了時からコイル巻取りまでの間の冷却速度
を4.7 、8.8 、11.6、15.6、26.5、55.8℃/sと変更し
た。これらの熱延板コイルは900 ℃の温度で30秒間の熱
延板焼鈍を行ったが、このとき昇温速度は12.6℃/sと
した。その後これらのコイルは酸洗し100 〜160 ℃の温
度でタンデム圧延機によって0.29mmの厚みにそれぞれ温
間圧延した。
Example 2 Molten steel having the chemical composition of steel symbol XII shown in Table 2 above was cast into a slab by a continuous casting machine while performing electromagnetic stirring, and the six slabs were subjected to the conditions shown by symbol b in Table 3 above. Were hot-rolled to obtain hot-rolled sheet coils each having a thickness of 2.2 mm. At this time, the cooling rate from the end of hot rolling to the coil winding was changed to 4.7, 8.8, 11.6, 15.6, 26.5 and 55.8 ° C / s. These hot-rolled sheet coils were annealed at a temperature of 900 ° C. for 30 seconds, and the heating rate was 12.6 ° C./s. Then, these coils were pickled and warm-rolled at a temperature of 100 to 160 ° C. by a tandem rolling mill to a thickness of 0.29 mm.

【0131】その後、脱脂処理を行い850 ℃の温度で2
分間の脱炭焼鈍を施し、0.05%のBを含有するMgO 中に
4%の TiO2 を添加した焼鈍分離剤を鋼板表面に塗布
し、昇温時500 ℃の温度までN2単独の雰囲気、その後85
0 ℃の温度まではN2:25%、H 2 :75%の混合雰囲気、
以後H2 単独雰囲気で1180℃の温度まで昇温後5時間保
持する最終仕上げ焼鈍を施したのち、未反応焼鈍分離剤
をそれぞれ除去した。これらのコイルはさらに50%のコ
ロイダルシリカを含有するりん酸マグネシウムを主成分
とする絶縁コーティングを塗布し800 ℃の温度で焼付け
それぞれ製品とした。
After that, degreasing treatment is performed at a temperature of 850 ° C. for 2 hours.
After decarburization annealing for 1 minute, it was added to MgO containing 0.05% B.
4% TiO2Applying an annealing separator with added to the steel plate surface
The temperature rises to 500 ° C2Alone atmosphere, then 85
N up to a temperature of 0 ° C2: 25%, H 2 : 75% mixed atmosphere,
After that H2 Hold for 5 hours after raising the temperature to 1180 ℃ in a single atmosphere
After carrying out the final finishing annealing, the unreacted annealing separator
Were removed respectively. These coils have an additional 50%
The main component is magnesium phosphate containing a colloidal silica
Apply an insulating coating and bake at a temperature of 800 ° C
Each product.

【0132】しかるのち、実施例1と同様の要領で、未
反応焼鈍分離剤を除去した鋼板でのフォルステライト質
被膜中のAl、TiおよびBの定量分析と結晶粒径分布、製
品の磁気特性および各製品を用いて作製したEIコアの鉄
損などをそれぞれ調査した。これらの調査結果を表10に
まとめて示す。
Thereafter, in the same manner as in Example 1, quantitative analysis of Al, Ti and B in the forsterite coating and the crystal grain size distribution of the steel sheet from which the unreacted annealing separator was removed and the magnetic properties of the product were obtained. And the iron loss etc. of the EI core produced using each product were investigated respectively. The results of these surveys are summarized in Table 10.

【0133】[0133]

【表10】 [Table 10]

【0134】表10に示すように熱間圧延終了後からコイ
ル巻取りまでの間の冷却速度が10℃/s以上のこの発明
の構成要件を満足する方向性電磁鋼板は高磁場特性に比
較して低磁場での鉄損特性に優れ、実機での鉄損が極め
て良好である。
As shown in Table 10, the grain-oriented electrical steel sheets satisfying the constitutional requirements of the present invention having a cooling rate of 10 ° C./s or more from the end of hot rolling to the coil winding are compared with high magnetic field characteristics. And excellent iron loss characteristics in low magnetic fields, and extremely good iron loss in actual equipment.

【0135】実施例3 前掲表2に示した鋼記号XIV の成分組成の溶鋼を電磁攪
拌を行いながら鋳込んだスラブ4本と電磁攪拌を中止し
て鋳込んだスラブ1本のうち、電磁攪拌をした4本のス
ラブは前掲表3に示したa,b、eおよびfの条件でそ
れぞれ熱間圧延し、2.6 mmの厚みの熱延板コイルとした
が電磁攪拌をしなかったスラブについては表3の条件e
で熱間圧延を行った(板厚:2.6 mm)。このとき、熱間
圧延終了時からコイル巻取りまでの間の冷却速度として
は21.6〜26.2℃/sの急冷とした。その後これらのコイ
ルは全て2分割し、一方は900 ℃の温度で60秒間、他方
は1050℃の温度で60秒間の熱延板焼鈍を施した。さら
に、これらのコイルは酸洗後120 ℃の温度でタンデム圧
延機によってそれぞれ0.26mmの厚みに温間圧延した。
Example 3 Of the four slabs in which molten steel having the chemical composition of steel symbol XIV shown in Table 2 above was cast while performing electromagnetic stirring and one slab cast after the electromagnetic stirring was stopped, electromagnetic stirring was performed. The four slabs that were subjected to hot rolling under the conditions of a, b, e, and f shown in Table 3 above were hot rolled sheet coils with a thickness of 2.6 mm. Condition e in Table 3
Was hot-rolled (sheet thickness: 2.6 mm). At this time, the cooling rate from the end of hot rolling to the coil winding was 21.6 to 26.2 ° C./s. Thereafter, all of these coils were divided into two, one of which was subjected to hot-rolled sheet annealing at a temperature of 900 ° C. for 60 seconds and the other of which at a temperature of 1050 ° C. for 60 seconds. Further, these coils were pickled and warm-rolled to a thickness of 0.26 mm by a tandem rolling mill at a temperature of 120 ° C.

【0136】その後、脱脂処理を行い850 ℃の温度で2
分間の脱炭焼鈍を施し、0.1 %のBを含有するMgO 中に
5%のTiO2を添加した焼鈍分離剤を鋼板表面に塗布し、
昇温時800 ℃の温度までN2 単独の雰囲気、その後1050
℃の温度まではN2 :25%、H2 :75%の混合雰囲気、
以後H2 単独雰囲気で1200℃の温度まで昇温後5時間保
持する最終仕上げ焼鈍を施したのち、未反応焼鈍分離剤
をそれぞれ除去した。これらのコイルはさらに60%のコ
ロイダルシリカを含有するりん酸マグネシウムを主成分
とする絶縁コーティングを塗布し800 ℃の温度で焼付け
それぞれ製品とした。
After that, degreasing treatment is performed at a temperature of 850 ° C. for 2 hours.
Decarburization annealing for 1 minute, and then applying an annealing separator containing 5% TiO 2 in MgO containing 0.1% B to the steel sheet surface,
At the time of temperature rise, an atmosphere of N 2 alone up to a temperature of 800 ° C, then 1050
Up to ℃ temperature, mixed atmosphere of N 2 : 25%, H 2 : 75%,
After that, after performing final finish annealing in which the temperature was raised to 1200 ° C. in a single atmosphere of H 2 and held for 5 hours, the unreacted annealing separator was removed. Each of these coils was further coated with an insulating coating containing magnesium phosphate as a main component containing 60% of colloidal silica, and baked at a temperature of 800 ° C to obtain each product.

【0137】しかるのち、実施例1と同様の要領によ
り、未反応焼鈍分離剤を除去した鋼板でのフォルステラ
イト質被膜中のAl、TiおよびBの定量分析、結晶粒径分
布、製品の磁気特性および各製品を用いて作製したEI
コアの鉄損などをそれぞれ調査した。これらの調査結果
を表11にまとめて示す。
Then, in the same manner as in Example 1, quantitative analysis of Al, Ti and B in the forsterite coating on the steel sheet from which the unreacted annealing separator was removed, the grain size distribution, and the magnetic properties of the product were obtained. And EI made using each product
The iron loss of the core was investigated. The results of these surveys are summarized in Table 11.

【0138】[0138]

【表11】 [Table 11]

【0139】表11に示すようにスラブ加熱温度が1250℃
以下でかつ熱延板焼鈍温度が900 ℃のこの発明構成要件
を満足する方向性電磁鋼板は高磁場特性に比較して低磁
場での鉄損特性に優れ、実機での鉄損が極めて良好であ
る。
As shown in Table 11, the slab heating temperature is 1250 ° C.
The grain-oriented electrical steel sheet which satisfies the requirements of this invention with the hot-rolled sheet annealing temperature of 900 ° C or less is excellent in the iron loss characteristics in the low magnetic field as compared with the high magnetic field characteristics, and the iron loss in the actual machine is extremely good. is there.

【0140】実施例4 前掲表2に示した鋼記号VIIIの成分組成の溶鋼を電磁攪
拌を行いながら連続鋳造機でスラブに鋳込んだ。このス
ラブを7本、前掲表3の記号bに示した条件で熱間圧延
し、それぞれ(a)2.0mm、(b)2.2mm、(c)2.5mm、(d)2.7m
m、(e)3.2mm、(f)3.6mm、(g)13 mmの厚みの熱延板コイ
ルとした。この時、熱間圧延終了時からコイル巻取り時
までの間の冷却速度は27.5℃/sとした。これらの熱延
板コイルは昇温速度7.8 ℃/sで、かつ900 ℃の温度で
30秒間の熱延板焼鈍を行い、酸洗後、冷間圧延によりそ
れぞれ0.49mmの厚みに圧延した。したがって(a) のコイ
ルの圧下率は76%、(b) のコイルの圧下率は78%、(c)
のコイルの圧下率は80%、(d) のコイルの圧下率は82
%、(e) のコイルの圧下率は85%、(f) のコイルの圧下
率は86%、(g) のコイル圧下率は96%である。このと
き、これらのコイルは120〜180 ℃の温度でタンデム圧
延機による温間圧延を施した。
Example 4 Molten steel having a component composition of steel symbol VIII shown in Table 2 above was cast into a slab by a continuous casting machine while performing electromagnetic stirring. Seven of these slabs were hot-rolled under the conditions indicated by the symbol b in Table 3 above, and respectively (a) 2.0 mm, (b) 2.2 mm, (c) 2.5 mm, (d) 2.7 m
m, (e) 3.2 mm, (f) 3.6 mm, (g) 13 mm thick hot rolled sheet coil. At this time, the cooling rate from the end of hot rolling to the coil winding was 27.5 ° C / s. These hot-rolled sheet coils have a heating rate of 7.8 ° C / s and a temperature of 900 ° C.
The hot-rolled sheet was annealed for 30 seconds, pickled, and then cold-rolled to a thickness of 0.49 mm. Therefore, the coil reduction rate of (a) is 76%, the coil reduction rate of (b) is 78%, and (c)
The coil rolling ratio is 80%, and the coil rolling ratio in (d) is 82%.
%, The coil rolling reduction of (e) is 85%, the coil rolling reduction of (f) is 86%, and the coil rolling reduction of (g) is 96%. At this time, these coils were subjected to warm rolling by a tandem rolling mill at a temperature of 120 to 180 ° C.

【0141】その後、各コイルは脱脂処理を行い850 ℃
の温度で2分間の脱炭焼鈍を施し、0.08%のBを含有す
るMgO 中に7%のTiO2を添加した焼鈍分離剤を鋼板表面
に塗布し、昇温時700 ℃の温度までN2 単独の雰囲気、
その後850 ℃の温度まではN 2 :25%、H2 :75%の混
合雰囲気、以後H2 単独雰囲気で1200℃の温度まで昇温
後5時間保持する最終仕上げ焼鈍を施し、その後未反応
焼鈍分離剤をそれぞれ除去した。これらのコイルはさら
に60%のコロイダルシリカを含有するりん酸マグネシウ
ムを主成分とする絶縁コーティングを塗布し800 ℃の温
度で焼付け製品とした。
After that, each coil is degreased at 850 ° C.
Decarburization annealing for 2 minutes at the temperature of 0.08% B
7% TiO in MgO2Annealing agent with added
Applied to N and up to a temperature of 700 ° C2 Single atmosphere,
After that, N up to a temperature of 850 ℃ 2 : 25%, H2 : 75% mixed
Combined atmosphere, then H2 Temperature rises to 1200 ℃ in a single atmosphere
After final finishing annealing of holding for 5 hours, then unreacted
The annealing separator was removed respectively. These coils are even more
Magnesium phosphate containing 60% colloidal silica
Apply an insulating coating consisting mainly of
The product was baked at a certain degree.

【0142】しかるのち、実施例1と同様の要領で、未
反応焼鈍分離剤を除去した鋼板でのフォルステライト質
被膜中のAl、TiおよびBの定量分析と結晶粒径分布、製
品の磁気特性および各製品を用いて作製したEIコアの
鉄損などをそれぞれ調査した。これらの調査結果を表12
にまとめて示す。
After that, in the same manner as in Example 1, quantitative analysis of Al, Ti and B in the forsterite coating on the steel sheet from which the unreacted annealing separator was removed, the grain size distribution, and the magnetic properties of the product were obtained. And the iron loss of the EI core produced using each product was investigated. The results of these surveys are shown in Table 12.
Are shown together.

【0143】[0143]

【表12】 [Table 12]

【0144】表12に示すように冷間圧延の圧下率を80〜
95%としたこの発明構成要件を満足する方向性電磁鋼板
は高磁場特性に比較して低磁場での鉄損特性に優れ、実
機での鉄損が極めて良好である。
As shown in Table 12, the reduction ratio of cold rolling was 80 to
The grain-oriented electrical steel sheet satisfying the constituent requirements of the present invention of 95% is superior to the high magnetic field characteristic in the iron loss characteristic in the low magnetic field, and the iron loss in the actual machine is extremely good.

【0145】実施例5 前掲表2に示した鋼記号Iの成分組成を有する溶鋼を連
続鋳造機で電磁攪拌を行いながらスラブに鋳込んだ。こ
のスラブ9本を、前掲表3の記号bに示した条件で熱間
圧延し、それぞれ2.4mm の厚みの熱延板コイルとした。
このとき、熱間圧延終了時からコイル巻取り時までの間
の冷却速度は14.5℃/sとした。これらの熱延板コイル
は昇温速度6.5 ℃/sで、かつ900 ℃の温度で30秒間の
熱延板焼鈍を行い、酸洗後、タンデム圧延機により170
〜220 ℃の温度で温間圧延を施し、それぞれ0.34mmの厚
みに圧延した。
Example 5 Molten steel having the chemical composition of steel symbol I shown in Table 2 above was cast into a slab while performing electromagnetic stirring with a continuous casting machine. Nine of these slabs were hot-rolled under the conditions indicated by the symbol b in Table 3 above to obtain hot-rolled sheet coils each having a thickness of 2.4 mm.
At this time, the cooling rate from the end of hot rolling to the coil winding was 14.5 ° C / s. These hot-rolled sheet coils were subjected to hot-rolled sheet annealing at a temperature rising rate of 6.5 ° C / s and at a temperature of 900 ° C for 30 seconds, pickled, and then cooled to 170 by a tandem rolling mill.
Warm rolling was performed at a temperature of ~ 220 ° C, and each was rolled to a thickness of 0.34 mm.

【0146】その後、各コイルは脱脂処理を行い850 ℃
の温度で2分間の脱炭焼鈍を施したのち、前掲表6に示
した組成の焼鈍分離剤と焼鈍雰囲気条件によって各コイ
ルに最終仕上げ焼鈍を施した。最終仕上げ焼鈍は、1180
℃の温度まで30℃/sの昇温速度で昇温し7時間保持し
たのち降温するヒートパターンとした。その後未反応焼
鈍分離剤を除去した。これらのコイルはさらに60%のコ
ロイダルシリカを含有するりん酸マグネシウムを主成分
とする絶縁コーティングを塗布し800 ℃の温度で焼付け
製品とした。
After that, each coil is degreased at 850 ° C.
After performing decarburization annealing at the temperature of 2 minutes, each coil was subjected to final finish annealing by using the annealing separator having the composition shown in Table 6 and the annealing atmosphere conditions. Final finish annealing is 1180
A heat pattern was used in which the temperature was raised to 30 ° C. at a heating rate of 30 ° C., held for 7 hours, and then lowered. After that, the unreacted annealing separator was removed. These coils were further coated with an insulating coating composed mainly of magnesium phosphate containing 60% colloidal silica and baked at a temperature of 800 ° C.

【0147】しかるのち、実施例1と同様の要領で、未
反応焼鈍分離剤を除去した鋼板でのフォルステライト質
被膜中のAl、TiおよびBの定量分析と結晶粒径分布、製
品の磁気特性および各製品を用いて作製したEIコアの鉄
損などをそれぞれ調査した。これらの調査結果を表13に
まとめて示す。
Then, in the same manner as in Example 1, quantitative analysis of Al, Ti and B in the forsterite coating and the crystal grain size distribution of the steel sheet from which the unreacted annealing separator was removed and the magnetic properties of the product were obtained. And the iron loss etc. of the EI core produced using each product were investigated respectively. The results of these surveys are summarized in Table 13.

【0148】[0148]

【表13】 [Table 13]

【0149】表13に示すように焼鈍分離剤の組成と最終
仕上げ焼鈍の雰囲気条件をこの発明構成要件を満足する
ものとした方向性電磁鋼板は高磁場特性に比較して低磁
場での鉄損特性に優れ、実機での鉄損が極めて良好であ
る。
As shown in Table 13, the grain-oriented electrical steel sheet in which the composition of the annealing separator and the atmosphere condition of the final finish annealing satisfy the constituent requirements of the invention has iron loss in a low magnetic field as compared with high magnetic field characteristics. Excellent properties and extremely good iron loss in actual equipment.

【0150】[0150]

【発明の効果】この発明のうち請求項1ないし2の発明
は、結晶粒径分布およびフォルステライト質被膜の組成
を特定する方向性電磁鋼板であり、請求項3ないし5の
発明は、成分組成を特定した素材を用い、熱間圧延条
件、冷間圧延条件、焼鈍分離剤組成および最終仕上げ焼
鈍条件を特定して方向性電磁鋼板を製造するものであ
り、これらの発明の方向性電磁鋼ならびにその製造方法
に従えば、高磁場に比し低磁場での鉄損特性に優れる方
向性電磁鋼板となり、これを鉄心として用いた小型の発
電機や変圧器など実機の鉄損特性を大幅に向上できる。
EFFECTS OF THE INVENTION Of the present invention, the inventions of claims 1 and 2 are grain-oriented electrical steel sheets which specify the grain size distribution and composition of the forsterite coating. Using the specified material, hot rolling conditions, cold rolling conditions, annealing separator composition and final finishing annealing conditions are specified to produce the grain-oriented electrical steel sheet, and the grain-oriented electrical steels of these inventions and According to its manufacturing method, it becomes a grain-oriented electrical steel sheet that excels in iron loss characteristics in a low magnetic field compared to a high magnetic field, and greatly improves the iron loss characteristics of actual machines such as small generators and transformers that use this as an iron core. it can.

【図面の簡単な説明】[Brief description of drawings]

【図1】粒径が1mm未満の結晶粒径の個数比率とEIコ
アの鉄損および鉄損比W10/50/W17/50 との関係を示
すグラフである。
FIG. 1 is a graph showing the relationship between the number ratio of crystal grain sizes having a grain size of less than 1 mm and the iron loss of the EI core and the iron loss ratio W 10/50 / W 17/50 .

【図2】粒径が4mm以上、7mm未満の結晶粒の個数比率
および7mm以上の結晶粒の個数比率とEIコアの鉄損と
の関係を示すグラフである。
FIG. 2 is a graph showing the relationship between the number ratio of crystal grains having a grain size of 4 mm or more and less than 7 mm, the number ratio of crystal grains having a grain size of 7 mm or more, and the iron loss of the EI core.

【図3】結晶粒径分布がこの発明の範囲に適合するもの
について、フォルステライト質被膜中のAl, TiおよびB
含有量とEIコアの鉄損との関係を示すグラフである。
FIG. 3 shows Al, Ti and B in a forsterite coating for a crystal grain size distribution which conforms to the scope of the present invention.
It is a graph which shows the relationship between content and the iron loss of EI core.

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 FI C22C 38/06 C22C 38/06 H01F 1/16 H01F 1/16 B (72)発明者 本田 厚人 岡山県倉敷市水島川崎通1丁目(番地な し) 川崎製鉄株式会社 水島製鉄所内 (72)発明者 千田 邦浩 岡山県倉敷市水島川崎通1丁目(番地な し) 川崎製鉄株式会社 水島製鉄所内 (56)参考文献 特開 平7−268470(JP,A) 特開 平5−304016(JP,A) 特開 昭52−153827(JP,A) 特開 昭60−145382(JP,A) 特開 昭60−59045(JP,A) (58)調査した分野(Int.Cl.7,DB名) C22C 38/00 303 B21B 3/02 C21D 8/12 C21D 9/46 501 C22C 38/04 C22C 38/06 H01F 1/16 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 7 Identification symbol FI C22C 38/06 C22C 38/06 H01F 1/16 H01F 1/16 B (72) Inventor Atsuto Honda Atsushi Mizushima Kawasaki, Kurashiki City, Okayama Prefecture 1-chome (without street number) Kawasaki Steel Co., Ltd. Mizushima Steel Works (72) Inventor Kunihiro Senda 1-chome (without street number) Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture Kawasaki Steel Co., Ltd. Mizushima Steel Works (56) References 7-268470 (JP, A) JP 5-304016 (JP, A) JP 52-153827 (JP, A) JP 60-145382 (JP, A) JP 60-59045 (JP, A) (58) Fields investigated (Int.Cl. 7 , DB name) C22C 38/00 303 B21B 3/02 C21D 8/12 C21D 9/46 501 C22C 38/04 C22C 38/06 H01F 1/16

Claims (5)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】 Si:1.5 〜7.0 wt%およびMn:0.03〜2.
5 wt%を含有し、C,SおよびNの含有量をそれぞれ
C:0.003 wt%以下、S:0.002 wt%以下およびN:0.
002 wt%以下とし、残部Feおよび不可避的不純物からな
電磁鋼板であって、 該鋼板の板厚方向に貫通する結晶粒の鋼板面内方向の粒
径の個数比率が、1mm未満:25〜98%、4mm以上7mm未
満:45%以下および7mm以上:10%以下であり、 該鋼板表面にはフォルステライト質被膜を有し、その被
膜中にAl:0.5 〜15wt%、Ti:0.1 〜10wt%およびB:
0.01〜0.8 wt%を含有していることを特徴とする鉄損特
性に優れる方向性電磁鋼板。
1. Si: 1.5 to 7.0 wt% and Mn: 0.03 to 2.
5% by weight, and the contents of C, S and N were C: 0.003 wt% or less, S: 0.002 wt% or less and N: 0.
002 wt% or less , with no balance of Fe and unavoidable impurities
Which is a magnetic steel sheet, wherein the number ratio of grain sizes of crystal grains penetrating in the thickness direction of the steel sheet in the in-plane direction of the steel sheet is less than 1 mm: 25 to 98%, 4 mm or more and less than 7 mm: 45% or less and 7 mm or more : 10% or less, the surface of the steel sheet has a forsterite coating, and Al : 0.5 to 15 wt%, Ti: 0.1 to 10 wt% and B:
A grain-oriented electrical steel sheet with excellent iron loss characteristics, characterized by containing 0.01 to 0.8 wt%.
【請求項2】 さらにSb:0.0010〜0.080 wt%を含有す
ることを特徴とする請求項1に記載の鉄損特性に優れる
方向性電磁鋼板。
2. Sb: 0.0010 to 0.080 wt% is further contained.
The grain- oriented electrical steel sheet having excellent iron loss characteristics according to claim 1 .
【請求項3】C:0.005 〜0.070 wt%、 Si:1.5 〜7.0 wt%、 Mn:0.03〜2.5 wt%、 Al:0.005 〜0.017 wt%および N:0.0030〜0.0100wt% を含み、かつ、Ti,Nb,BまたはSbのうちから選ばれる
1種または2種以上をそれぞれ Ti:0.0005〜0.0020wt% Nb:0.0010〜0.010 wt% B:0.0001〜0.0020wt%および Sb:0.0010〜0.080 wt% で含有し、残部Feおよび不可避的不純物からなる溶鋼を
鋳造してけい素鋼スラブとなし、該スラブを素材として
1250℃以下の温度に加熱して熱間圧延を行うかもしくは
直接熱間圧延して800 〜970 ℃の温度範囲で仕上げ圧延
を終了したのち、10℃/s以上の冷却速度で急冷して67
0 ℃以下の温度でコイルに巻取り、その後、昇温速度:
5〜25℃/sの範囲で昇温し800 〜950 ℃の温度範囲で
100 秒間以下保持する熱延板焼鈍を施したのち、タンデ
ム圧延機により圧下率:80〜95%の冷間圧延後、1次再
結晶焼鈍を施し、Ti化合物:1〜20wt%およびB:0.04
〜1.0 wt%を含有する焼鈍分離剤を塗布してから、昇温
途中の少なくとも850 ℃以上の温度からはH2 を含有す
る雰囲気中で昇温・保持する最終仕上げ焼鈍を施すこと
を特徴とする鉄損特性に優れる方向性電磁鋼板の製造方
法。
3. C: 0.005-0.070 wt%, Si: 1.5-7.0 wt%, Mn: 0.03-2.5 wt%, Al: 0.005-0.017 wt% and N: 0.0030-0.0100 wt%, and Ti , Nb, B or Sb selected from the group consisting of one or more selected from Ti: 0.0005 to 0.0020 wt% Nb: 0.0010 to 0.010 wt% B: 0.0001 to 0.0020 wt% and Sb: 0.0010 to 0.080 wt% Then, a molten steel consisting of the balance Fe and unavoidable impurities is cast into a silicon steel slab, and the slab is used as a raw material.
After heating to a temperature of 1250 ° C or lower for hot rolling or direct hot rolling to finish rolling in the temperature range of 800 to 970 ° C, quenching is performed at a cooling rate of 10 ° C / s or more to 67
The coil is wound at a temperature of 0 ° C or less, and then the heating rate:
In the temperature range of 800 to 950 ℃, the temperature is raised in the range of 5 to 25 ℃ / s.
After hot-rolled sheet annealing for 100 seconds or less, cold rolling with a tandem rolling mill at a rolling reduction of 80 to 95%, primary recrystallization annealing, and Ti compound: 1 to 20 wt% and B: 0.04
It is characterized in that after applying an annealing separator containing 1.0 wt% to 1.0 wt%, a final finish annealing is performed in which the temperature is raised and held in an atmosphere containing H 2 from a temperature of at least 850 ° C. or higher during heating. Method for producing grain-oriented electrical steel sheet with excellent iron loss characteristics.
【請求項4】 溶鋼が、さらにCrまたはSnの1種または
2種を、 Cr:0.0010〜0.30wt%および Sn:0.0010〜0.30wt% で含有することを特徴とする請求項3に記載の鉄損特性
に優れる方向性電磁鋼板の製造方法。
4. The iron according to claim 3, wherein the molten steel further contains one or two kinds of Cr or Sn at Cr: 0.0010 to 0.30 wt% and Sn: 0.0010 to 0.30 wt%. A method for manufacturing a grain-oriented electrical steel sheet having excellent loss characteristics.
【請求項5】 鋳造時に電磁攪拌を施すことを特徴とす
る請求項3または4に記載の鉄損特性に優れる方向性電
磁鋼板の製造方法。
5. The method for producing a grain-oriented electrical steel sheet having excellent iron loss characteristics according to claim 3, wherein electromagnetic stirring is performed during casting.
JP27813696A 1996-10-21 1996-10-21 Grain-oriented electrical steel sheet with excellent iron loss characteristics and method of manufacturing the same Expired - Fee Related JP3456352B2 (en)

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JP27813696A JP3456352B2 (en) 1996-10-21 1996-10-21 Grain-oriented electrical steel sheet with excellent iron loss characteristics and method of manufacturing the same
US08/954,504 US6039818A (en) 1996-10-21 1997-10-20 Grain-oriented electromagnetic steel sheet and process for producing the same
CNB971252890A CN1153227C (en) 1996-10-21 1997-10-20 Grain-oriented electromagnetic steel sheet and process for producing the same
KR1019970053853A KR100440994B1 (en) 1996-10-21 1997-10-20 Directional electromagnetic steel sheet and manufacturing method thereof
EP97118278A EP0837149B1 (en) 1996-10-21 1997-10-21 Grain-oriented electromagnetic steel sheet and process for producing the same
DE69705688T DE69705688T2 (en) 1996-10-21 1997-10-21 Grain-oriented electromagnetic steel sheet and its manufacturing process
US09/493,864 US6331215B1 (en) 1996-10-21 2000-01-28 Process for producing grain-oriented electromagnetic steel sheet

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