JP4163773B2 - Method for producing grain-oriented electrical steel sheet - Google Patents
Method for producing grain-oriented electrical steel sheet Download PDFInfo
- Publication number
- JP4163773B2 JP4163773B2 JP35915997A JP35915997A JP4163773B2 JP 4163773 B2 JP4163773 B2 JP 4163773B2 JP 35915997 A JP35915997 A JP 35915997A JP 35915997 A JP35915997 A JP 35915997A JP 4163773 B2 JP4163773 B2 JP 4163773B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic flux
- flux density
- steel sheet
- oriented electrical
- electrical steel
- 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
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets 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
- H01F1/14—Magnets 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
- H01F1/147—Alloys characterised by their composition
- H01F1/14766—Fe-Si based alloys
- H01F1/14775—Fe-Si based alloys in the form of sheets
Description
【０００１】
【発明の属する技術分野】
本発明は、磁束密度が極めて高い方向性電磁鋼板の製造法に関するものである。
【０００２】
【従来の技術】
方向性電磁鋼板は、二次再結晶法により鋼板の結晶粒を特定方位に高度に配向させた成品であることが特徴であり、圧延面に｛１１０｝面、圧延方向に＜１００＞軸を有するいわゆるゴス方位を持つ結晶粒により構成されている。
【０００３】
また、方向性電磁鋼板の用途としては、軟磁性材料として主にトランスその他の電気機器の鉄心材料に使用されるもので、近年省エネルギー、省資源への社会的要求がますます厳しくなっている事から、方向性電磁鋼板の鉄損低減、磁化特性改善への要求も厳しくなってきている。このため磁気特性、特に良好な励磁特性と鉄損特性が求められるようになってきている。
【０００４】
方向性電磁鋼板の励磁特性を示す指標としては、通常磁束密度Ｂ8 （磁界の強さ８００Ａ／ｍにおける磁束密度）が用いられている。また鉄損特性を示す指標としては、Ｗ17/50 （５０Ｈｚで１．７Ｔの磁束密度まで磁化させたときの単位重量あたりの鉄損）等が用いられている。
【０００５】
鉄損は渦電流損とヒステリシス損からなり、渦電流損は鋼板の電気抵抗率、板厚、結晶粒度、磁区の形態、鋼板表面の皮膜張力等の因子により支配されている。一方、ヒステリシス損は磁束密度を支配する鋼板の結晶方位、純度、内部歪等により支配される。
【０００６】
従来、鉄損を低減させるために、Ｓｉ含有量を高め鋼板の電気抵抗を大きくすることが行われてきた。しかしながら、Ｓｉ含有量を高めるのに伴い飽和磁束密度が低下するため、これを従来技術では二次再結晶方位の集積度を上昇させることで補って高磁束密度方向性電磁鋼板を製造してきた。
【０００７】
このために、従来技術においては、二次再結晶を安定して発現させるとともにその方位集積度を高め、磁束密度を向上させる因子として、インヒビターの役割が重要である。この目的のため、従来技術ではＭｎＳ、ＡｌＮ、ＭｎＳｅ等がインヒビターとして用いられてきている。
【０００８】
従来の方向性電磁鋼板の製造法は、二次再結晶方位制御に用いられるインヒビターの種類により大きく３種類に大別される。
【０００９】
第一は、M.F.Littmannにより特公昭３０−３６５１号公報に開示されている、インヒビターにＭｎＳ用い、二回冷延法で製造する方法である。第二、特公昭４０−１５６４４号公報に田口、坂倉らにより開示された、ＭｎＳに加えてＡｌＮをインヒビターとする製造方法である。このインヒビターにＡｌＮを用いる方法により、方向性電磁鋼板のＢ8 は１．８７０Ｔ以上に向上し、磁気特性の改善による省エネルギーに多大な貢献を果たした。第三に、特公昭５１−１３４６９号公報に今中等により開示されたＭｎＳとＳｂもしくはＭｎＳ、ＭｎＳｅとＳｂを用い、二回冷延法により製造する方法である。
【００１０】
これらの従来法においては本質的あるいは良好な磁束密度を得るためにはインヒビターの析出制御を目的として、高温スラブ加熱により一旦インヒビターを構成する析出物を溶体化し、これを熱延工程あるいは特公昭４６−２３８２０号公報に開示されているように熱延板焼鈍時に微細に析出させることが必要である。このように従来法では製鋼段階での成分調整と熱延の段階でほぼ製品の特性が決定されるため、上工程での材質造り込みの安定性確立が重要な課題であった。
【００１１】
これらの従来法においては、鉄損を低減させることが第一目標であり、その目標を達成するために磁束密度を高めることが特徴であった。何故ならば、方向性電磁鋼板の皮膜張力の効果と磁束密度の間には、J.Appl.Phys.,vol.41.no.7.p2981-2984(1970) に指摘されているように、磁束密度Ｂ8 の値が高いほどその鉄損低減効果が大きいことが知られている。また磁区細分化による鉄損低減法は特開昭５８−５９６８号公報、特開昭５８−２６４０５号公報に述べられているが、磁区細分化処理前のプレーン材の磁束密度が高いほどその効果が大きいことが知られているからである。
【００１２】
一方、近年では、トランス鉄心において特に小型軽量／高性能化のために、従来の方向性電磁鋼板とは異なり、鉄損よりも高磁束密度を重視する需要家の要求が高まってきており、その製造技術の確立が急がれていた。高磁束密度を得るためには従来技術で重視されたように方位集積度を上げることの他に、材料中の鉄そのものの含有量を高め、飽和磁束密度を上げることが有効である。鉄は２．１６Ｔという高い飽和磁束密度を持っている。しかし、鉄にＳｉ等の非磁性不純物を添加すると飽和磁束密度は低下する。例えば、３％のＳｉを鉄に添加すると飽和磁束密度は２．０３Ｔにまで低下してしまう。したがって、不純物の低減による飽和磁束密度の向上は、高磁束密度を得るためには大変効果的である。
【００１３】
発明者等はこの目的で、これまでに特公平７−１２２０９３号公報、特開平４−３０１０５３号公報等で、高磁束密度方向性電磁鋼板の製造法について開示を行ってきた。しかしながら、近年では小型トランスの鉄心材料等において、これらの製造法による高磁束密度方向性電磁鋼板よりも、高磁場における飽和磁束密度の高いものが要求されているのが現状である。
【００１４】
【発明が解決しようとする課題】
本発明は、上述したように、小型トランスの鉄心材料等において近年要求されているような高磁束密度方向性電磁鋼板であって、従来の製造方法で得られていた製品よりも、高磁場における飽和磁束密度の高い高磁束密度方向性電磁鋼板の製造法を提供することを目的とする。
【００１６】
【課題を解決するための手段】
本発明の要旨とするところは以下の通りである。
（１）質量％で、
０．０１０％≦Ｃ≦０．１４％、
０．０１０％≦酸可溶性Ａｌ≦０．０５０％、
０．００３０％≦Ｎ≦０．０１５０％
を含有し、残部がＦｅ及び不可避的不純物からなるスラブを、加熱、熱延した後、１回以上の冷延を行って最終板厚とし、脱炭焼鈍後、Ａｃ１変態点以下の温度域で最終焼鈍する方向性電磁鋼板の製造方法であって、最終冷延圧下率を７５％以上９０％以下とし、８９０℃×１０時間の仕上げ焼鈍を行い、８００Ａ／ｍでの磁束密度：Ｂ８≧１．９０Ｔ、かつ１００００Ａ／ｍでの磁束密度：Ｂ１００≧２．１０Ｔとすることを特徴とする方向性電磁鋼板の製造方法。
【００１７】
【発明の実施の形態】
本発明者らは、従来技術での検討の主眼とされたインヒビター制御技術以外の製造プロセス上の検討課題として、鉄損の中の渦電流損成分を低減するために成品板厚を薄くし、かつ高磁束密度も両立させるために、冷延条件の制御による磁束密度の高い方向性電磁鋼板の製造法について鋭意検討した結果、最終冷延圧下率を７５％以上９０％以下に制御することで、成品における結晶の［１００］の圧延方向から１０゜以内への集積度が７５％以上に向上し、磁束密度が向上することを見いだし、発明の完成に至った。
【００１８】
以下に本発明を詳細に説明する。
まず、本発明の製造方法で用いるスラブの含有成分について説明する。
Ｃはその含有量が０．０１０％未満になると二次再結晶が不安定となり、磁束密度が著しく低下するので０．０１０％以上とする。一方、０．１４％を超えると、脱炭焼鈍に要する時間が長くなりすぎ、不経済であるので０．１４％以下とする。
【００１９】
酸可溶性ＡｌはＮと化合してインヒビターであるＡｌＮを形成する。その含有量が０．０１０％未満であるとインヒビター析出量が不足し二次再結晶が不安定となるので０．０１０％以上とする。一方、その含有量が０．０５０％超となると析出状態が粗大化し、インヒビター効果が損なわれ磁束密度が低下するので、０．０５０％以下とする。
【００２０】
Ｎは０．００３０％以上０．０１５０％以下にする必要がある。０．０１５０％を超えるとブリスターと呼ばれる鋼板表面の膨れが発生するとともに、一次再結晶組織の調整が困難となるので０．０１５０％以下とする。一方、Ｎ含有量が０．００３０％未満であると、インヒビターであるＡｌＮの形成が不足し二次再結晶の発現が困難になるのでＮ含有量は０．００３０％以上とする。
【００２１】
本発明鋼は、このようなスラブを出発材として、後述のプロセスによって得られるものである。以下、本発明鋼の成分について説明する。
Ｃは脱炭焼鈍において低減されるが、製品である本発明鋼においてＣが０．００３０％を超えると磁気時効が問題となるので０．００３０％以下とする。また、スラブの成分としては０．０１０％〜０．０５０％含有されている酸可溶性Ａｌは、鋼板表面に形成される酸化被膜等に若干量が消費されるため、本発明鋼では単に０．０５０％以下とし、下限値は設けなかった。Ｎについても、脱炭焼鈍時等に若干量が鋼板から抜けるため、本発明鋼では０．０５０％以下として下限値は設けなかった。
【００２２】
そして、本発明では結晶の［１００］の圧延方向から１０゜以内への集積度を７５％以上とする。この値が７５％未満では所望の高磁束密度が得られないためである。従来、無方向性電磁鋼板の分野では鉄の純度を高めることにより磁束密度を向上することは行われていた。しかし、本発明のような方向性電磁鋼板の分野においては、鉄損低減のためにＳｉを添加することが通常であり、鉄の純度を高めて磁束密度を向上することは従来行われていない。このように製品において結晶の［１００］の圧延方向から１０゜以内への集積度を７５％以上とするには、後述のように最終冷延率を制御すればよい。
【００２３】
次に、本発明のプロセスについて説明する。
本発明の電磁鋼スラブは、転炉または電気炉等の溶解炉で鋼を溶製し、必要に応じて真空脱ガス処理し、次いで連続鋳造により、あるいは造塊後分塊圧延することによって得られる。
【００２４】
その後、熱間圧延に先立ちスラブ加熱が行われる。本発明のプロセスにおいては、スラブの加熱温度は適切に制御して主要インヒビターであるＡｌＮを鋼中に再固溶させることが肝要である。
【００２５】
このスラブを熱延して所定の厚みの熱延板とする。
熱延以降の工程については、析出物制御を目的として１回の圧延で最終板厚とする場合は最終冷延前に熱延板板焼鈍を行っても良い。また、２回以上の冷間圧延により最終板厚とする場合は、１回目の冷間圧延前に熱延板焼鈍を行っても良い。酸洗後、１回もしくは中間焼鈍を含む２回以上の冷間圧延により最終板厚とする。
【００２６】
ここで、高磁束密度を得るためには最終冷延率の制御が重要である。すなわち、７５％以上９０％以下である必要がある。最終冷延率がこの範囲を外れると、得られる製品の結晶方向を制御できず、本発明が目的とする超高磁束密度が得られないので、最終冷延率は７５％以上９０％以下に定める。
【００２７】
次に湿水素雰囲気などの雰囲気中で脱炭焼鈍をする。この焼鈍は、磁気時効等により成品板の磁気特性を劣化させるＣを問題のない量まで低減させるための焼鈍で、通常知られたプロセスで行う。
【００２８】
次いで焼鈍分離材を塗布し仕上げ焼鈍を行い、二次再結晶および引き続いて純化を行う。本発明の鋼はαγ変態を有するため、良好な二次再結晶方位を維持するために仕上げ焼鈍温度はαγ変態点以下で行う。二次再結晶完了後の純化焼鈍は水素雰囲気中で実施する。
【００２９】
この様にして得られた製品には、板間の絶縁を確保して鉄心としての鉄損を低下させるために、絶縁皮膜を塗布して最終製品としても良いし、皮膜を施さずに最終製品としても良い。
【００３０】
本発明による製造法における冷延圧下率と成品磁束密度との関係について実験結果に基づき説明する。
Ｃ：０．０５％、酸可溶性Ａｌ：０．０１８％、Ｎ：０．００６５％を含有し、残部Ｆｅおよび不可避的不純物からなるスラブを加熱後、熱延を行い厚み２．１mmの熱延板とした。得られた熱延板に８２５℃２分の熱延板焼鈍を施し、酸洗後、７３．８〜９１．９％の圧下率で冷延し、最終板厚を０．５５〜０．１７mmに仕上げた。これに８３０℃の湿水素雰囲気中で５分間の脱炭焼鈍を施し、その後乾水素中で８９０℃×１０時間の仕上焼鈍を行った。冷延圧下率と磁界の強さ８００，１００００Ａ／ｍでの磁束密度：Ｂ8 ，Ｂ100 の関係について表１に示す。
【００３１】
【表１】
表１より、冷延圧下率を７５％以上９０％以下の範囲とすることによって、鋼板の結晶方向を所望に制御することができ、結果として磁束密度Ｂ8 ≧１．９０，Ｂ100 ≧２．１０Ｔという極めて優れた磁束密度を有する方向性電磁鋼板が得られることがわかる。
【００３３】
【実施例】
［実施例１］
表２の成分を含有し、残部Ｆｅおよび不可避的不純物からなるスラブを加熱後、熱延して２．１mmの厚みの熱延板とした。得られた熱延板に８３０℃２分の熱延板焼鈍を施し、その後酸洗し７３．８〜９１．９％の冷延を施し、０．５５〜０．１７mmに仕上げた。これを８３０℃の湿水素雰囲気中で脱炭焼鈍を施した。その後８９０℃×１０時間の仕上焼鈍を行った。
【００３４】
【表２】
冷延圧下率と仕上げ焼鈍後の磁気特性との関係を表３に示す。表３より、冷延圧下率が７５〜９０％の場合に、鋼板の結晶方向を所望に制御することができ、結果として磁束密度Ｂ8 ≧１．９０，Ｂ100 ≧２．１０Ｔの良好な磁束密度を有する方向性電磁鋼板が得られることがわかる。
【００３６】
【表３】
［実施例２］
表４の成分を含有し、残部Ｆｅおよび不可避的不純物からなるスラブを加熱後、熱延して３．０mmの厚みの熱延板とした。得られた熱延板に８３０℃２分の熱延板焼鈍を施し、その後酸洗し７３．３〜９１．７％の一回の冷延を施し、０．８０〜０．２５mmに仕上げた。これを８３０℃の湿水素雰囲気中で脱炭焼鈍を施した。その後８９０℃×１０時間の仕上焼鈍を行った。
【００３８】
【表４】
冷延圧下率と仕上げ焼鈍後の磁気特性との関係を表５に示す。表５より、冷延圧下率が７５〜９０％の場合に、鋼板の結晶方向を所望に制御することができ、その結果として磁束密度Ｂ8 ≧１．９０，Ｂ100 ≧２．１０Ｔの良好な磁束密度を有する方向性電磁鋼板が得られることがわかる。
【００４０】
【表５】
［実施例３］
表６の成分を含有し、残部Ｆｅおよび不可避的不純物からなるスラブを加熱後、熱延して３．５mmの厚みの熱延板とした。得られた熱延板に８００℃９０秒の熱延板焼鈍を施し酸洗を施した。その後、一回目の冷間圧延により２．１mmに仕上げた。さらにこれに８３０℃９０秒の中間焼鈍を施し、その後これに７３．８〜９１．９％の圧下率の最終冷延を施し、０．５５〜０．１７mmに仕上げた。これを８３０℃の湿水素雰囲気中で脱炭焼鈍を施した。その後、８９０℃×１０時間の仕上焼鈍を行った。
【００４２】
【表６】
冷延圧下率と仕上げ焼鈍後の磁気特性との関係を表７に示す。表７より、冷延圧下率が７５〜９０％の場合に、鋼板の結晶方向を所望に制御することができ、その結果として磁束密度Ｂ8 ≧１．９０，Ｂ100 ≧２．１０Ｔの良好な磁束密度を有する方向性電磁鋼板が得られることがわかる。
【００４４】
【表７】
【発明の効果】
このように本発明によれば、磁束密度が極めて高い方向性電磁鋼板を製造することが可能である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a grain- oriented electrical steel sheet having a very high magnetic flux density.
[0002]
[Prior art]
The grain-oriented electrical steel sheet is characterized by being a product in which the crystal grains of the steel sheet are highly oriented in a specific orientation by a secondary recrystallization method, with the {110} plane on the rolling surface and the <100> axis in the rolling direction. It has a so-called goth orientation crystal grain.
[0003]
In addition, grain oriented electrical steel sheets are used mainly as core materials for transformers and other electrical equipment as soft magnetic materials, and in recent years, social demands for energy and resource savings have become increasingly severe. Therefore, demands for reducing iron loss and improving magnetic properties of grain-oriented electrical steel sheets are becoming stricter. For this reason, magnetic characteristics, in particular, good excitation characteristics and iron loss characteristics have been demanded.
[0004]
As an index indicating the excitation characteristics of the grain-oriented electrical steel sheet, a normal magnetic flux density B 8 (magnetic flux density at a magnetic field strength of 800 A / m) is used. As an index indicating the iron loss characteristic, W 17/50 (iron loss per unit weight when magnetized to a magnetic flux density of 1.7 T at 50 Hz) or the like is used.
[0005]
The iron loss is composed of eddy current loss and hysteresis loss, and the eddy current loss is governed by factors such as the electrical resistivity, the plate thickness, the crystal grain size, the magnetic domain form, and the film tension on the steel plate surface. On the other hand, the hysteresis loss is governed by the crystal orientation, purity, internal strain, etc. of the steel sheet that govern the magnetic flux density.
[0006]
Conventionally, in order to reduce iron loss, the Si content has been increased to increase the electrical resistance of the steel sheet. However, since the saturation magnetic flux density decreases as the Si content is increased, the prior art has compensated for this by increasing the degree of integration of secondary recrystallization orientation, and has produced high magnetic flux density grain-oriented electrical steel sheets.
[0007]
For this reason, in the prior art, the role of the inhibitor is important as a factor for causing the secondary recrystallization to be stably expressed, increasing the degree of orientation integration, and improving the magnetic flux density. For this purpose, MnS, AlN, MnSe, etc. have been used as inhibitors in the prior art.
[0008]
Conventional methods for producing grain-oriented electrical steel sheets are roughly classified into three types depending on the type of inhibitor used for secondary recrystallization orientation control.
[0009]
The first is a method disclosed in Japanese Patent Publication No. 30-3651 disclosed by MFLittmann in which MnS is used as an inhibitor and is produced by a double cold rolling method. The second is a production method disclosed in Japanese Patent Publication No. 40-15644 by Taguchi and Sakakura et al. Using AlN as an inhibitor in addition to MnS. By the method using AlN as the inhibitor, the B 8 of the grain-oriented electrical steel sheet was increased to 1.870 T or more, which greatly contributed to energy saving by improving the magnetic properties. Thirdly, a method of producing by the cold rolling method using MnS and Sb or MnS, MnSe and Sb disclosed in Japanese Patent Publication No. 51-13469.
[0010]
In these conventional methods, in order to obtain an essential or good magnetic flux density, for the purpose of controlling the precipitation of the inhibitor, the precipitate constituting the inhibitor is once formed into a solution by heating at a high temperature slab, and this is then subjected to a hot rolling process or JP-B-46. As disclosed in Japanese Patent No. 23820, it is necessary to finely precipitate during hot-rolled sheet annealing. In this way, in the conventional method, the characteristics of the product are almost determined in the component adjustment and hot rolling stages in the steel making stage, so the establishment of the stability of material building in the upper process has been an important issue.
[0011]
In these conventional methods, the first goal is to reduce the iron loss, and the magnetic flux density is increased to achieve the goal. Because, as pointed out in J.Appl.Phys., Vol.41.no.7.p2981-2984 (1970), between the effect of the film tension and magnetic flux density of grain-oriented electrical steel sheet, It is known that the higher the value of the magnetic flux density B 8, the greater the effect of reducing the iron loss. Further, the iron loss reduction method by magnetic domain subdivision is described in Japanese Patent Application Laid-Open Nos. 58-5968 and 58-26405. However, the higher the magnetic flux density of the plain material before the magnetic domain subdivision processing, the more effective the method. It is known that is large.
[0012]
On the other hand, in recent years, in order to improve the size and weight / performance of transformer iron cores, unlike conventional grain-oriented electrical steel sheets, there has been an increasing demand for consumers who place importance on high magnetic flux density rather than iron loss. There was an urgent need to establish manufacturing technology. In order to obtain a high magnetic flux density, it is effective to increase the saturation magnetic flux density by increasing the content of iron itself in the material in addition to increasing the orientation integration degree as emphasized in the prior art. Iron has a high saturation magnetic flux density of 2.16T. However, when a nonmagnetic impurity such as Si is added to iron, the saturation magnetic flux density decreases. For example, when 3% Si is added to iron, the saturation magnetic flux density is reduced to 2.03T. Therefore, the improvement of the saturation magnetic flux density by reducing the impurities is very effective for obtaining a high magnetic flux density.
[0013]
For this purpose, the inventors have disclosed a method for producing a high magnetic flux density grain-oriented electrical steel sheet in Japanese Patent Publication No. 7-122093 and Japanese Patent Application Laid-Open No. 4-301053. In recent years, however, iron core materials for small transformers are required to have a higher saturation magnetic flux density in a high magnetic field than high magnetic flux density grain-oriented electrical steel sheets produced by these manufacturing methods.
[0014]
[Problems to be solved by the invention]
As described above, the present invention is a high magnetic flux density grain-oriented electrical steel sheet that has recently been demanded in iron core materials for small transformers, etc., in a higher magnetic field than products obtained by conventional manufacturing methods. It aims at providing the manufacturing method of a high magnetic flux density directionality electrical steel sheet with a high saturation magnetic flux density.
[0016]
[Means for Solving the Problems]
The gist of the present invention is as follows.
(1) In mass%,
0.010% ≦ C ≦ 0.14%,
0.010% ≦ acid-soluble Al ≦ 0.050%,
0.0030% ≦ N ≦ 0.0150%
A slab containing Fe and the inevitable impurities, and after heating and hot rolling, the steel sheet is subjected to cold rolling at least once to obtain a final thickness, and after decarburization annealing, the temperature range below the Ac 1 transformation point Is a method for producing a grain-oriented electrical steel sheet that is finally annealed at a final cold rolling reduction rate of 75% or more and 90% or less , finish annealing at 890 ° C. for 10 hours , and magnetic flux density at 800 A / m: B 8 ≧ 1.90 T and magnetic flux density at 10000 A / m: B 100 ≧ 2.10 T
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The inventors of the present invention have made the product plate thickness thinner in order to reduce the eddy current loss component in the iron loss, as a study subject on the manufacturing process other than the inhibitor control technology that has been the subject of the investigation in the prior art, In addition, in order to achieve both high magnetic flux density, as a result of intensive studies on a method for producing a grain-oriented electrical steel sheet having high magnetic flux density by controlling cold rolling conditions, the final cold rolling reduction ratio is controlled to 75% or more and 90% or less. The inventors have found that the degree of integration within 10 ° of the [100] rolling direction of the crystal in the product is improved to 75% or more and the magnetic flux density is improved, and the invention has been completed.
[0018]
The present invention is described in detail below.
First, the components contained in the slab used in the production method of the present invention will be described.
When the content of C is less than 0.010%, secondary recrystallization becomes unstable, and the magnetic flux density is remarkably lowered. On the other hand, if it exceeds 0.14%, the time required for decarburization annealing becomes too long, which is uneconomical, so it is made 0.14% or less.
[0019]
Acid soluble Al combines with N to form the inhibitor AlN. If the content is less than 0.010%, the amount of inhibitor precipitation becomes insufficient and secondary recrystallization becomes unstable, so the content is made 0.010% or more. On the other hand, if the content exceeds 0.050%, the precipitation state becomes coarse, the inhibitor effect is impaired, and the magnetic flux density is lowered, so the content is made 0.050% or less.
[0020]
N needs to be 0.0030% or more and 0.0150% or less. If it exceeds 0.0150%, blistering of the steel plate surface called blister occurs and adjustment of the primary recrystallized structure becomes difficult, so 0.0150% or less. On the other hand, if the N content is less than 0.0030%, the formation of AlN as an inhibitor is insufficient and the occurrence of secondary recrystallization becomes difficult, so the N content is set to 0.0030% or more.
[0021]
The steel of the present invention is obtained by a process described later using such a slab as a starting material. Hereinafter, the components of the steel of the present invention will be described.
C is reduced in the decarburization annealing, but in the steel of the present invention, which is a product, if C exceeds 0.0030%, magnetic aging becomes a problem, so the content is made 0.0030% or less. Further, since the acid-soluble Al contained in the slab component in an amount of 0.010% to 0.050% is consumed in a slight amount by the oxide film formed on the surface of the steel plate, the steel of the present invention is merely 0. It was made into 050% or less, and the lower limit was not provided. Also for N, since a slight amount is lost from the steel sheet during decarburization annealing, the lower limit is not set as 0.050% or less in the steel of the present invention.
[0022]
In the present invention, the degree of accumulation within 10 ° from the [100] rolling direction of the crystal is set to 75% or more. This is because if this value is less than 75%, a desired high magnetic flux density cannot be obtained. Conventionally, in the field of non-oriented electrical steel sheets, the magnetic flux density has been improved by increasing the purity of iron. However, in the field of grain-oriented electrical steel sheets as in the present invention, it is usual to add Si to reduce iron loss, and it has not been conventionally performed to improve the magnetic flux density by increasing the purity of iron. . Thus, in order to increase the degree of accumulation within 10 ° from the [100] rolling direction of the crystal in the product to 75% or more, the final cold rolling rate may be controlled as described later.
[0023]
Next, the process of the present invention will be described.
The electromagnetic steel slab of the present invention is obtained by melting steel in a melting furnace such as a converter or an electric furnace, vacuum degassing treatment if necessary, and then performing continuous casting or rolling after ingot forming. It is done.
[0024]
Thereafter, slab heating is performed prior to hot rolling. In the process of the present invention, it is important that the heating temperature of the slab is appropriately controlled to re-dissolve the main inhibitor, AlN, in the steel.
[0025]
This slab is hot-rolled to obtain a hot-rolled sheet having a predetermined thickness.
About the process after hot rolling, when it is set as final board thickness by one rolling for the purpose of precipitate control, you may perform hot-rolled board annealing before final cold rolling. Moreover, when it is set as final sheet thickness by two or more cold rolling, you may perform hot-rolled sheet annealing before the 1st cold rolling. After pickling, the final thickness is obtained by cold rolling at least once including intermediate annealing or twice.
[0026]
Here, in order to obtain a high magnetic flux density, it is important to control the final cold rolling rate. That is, it needs to be 75% or more and 90% or less. If the final cold rolling rate is out of this range, the crystal orientation of the resulting product cannot be controlled, and the ultra-high magnetic flux density intended by the present invention cannot be obtained, so the final cold rolling rate is 75% or more and 90% or less. Determine.
[0027]
Next, decarburization annealing is performed in an atmosphere such as a wet hydrogen atmosphere. This annealing is an annealing for reducing C, which degrades the magnetic properties of the product plate due to magnetic aging or the like, to a problem-free amount, and is performed by a generally known process.
[0028]
Next, an annealing separator is applied and finish annealing is performed, followed by secondary recrystallization and subsequent purification. Since the steel of the present invention has an αγ transformation, the finish annealing temperature is not higher than the αγ transformation point in order to maintain a good secondary recrystallization orientation. The purification annealing after the completion of the secondary recrystallization is performed in a hydrogen atmosphere.
[0029]
In order to ensure the insulation between the plates and reduce the iron loss as the iron core, the product obtained in this way may be coated with an insulating film to make the final product, or the final product without coating. It is also good.
[0030]
The relationship between the cold rolling reduction ratio and the product magnetic flux density in the production method according to the present invention will be described based on experimental results.
C: 0.05%, acid-soluble Al: 0.018%, N: 0.0065%, and after heating the slab composed of the remaining Fe and inevitable impurities, hot rolling is performed to obtain a 2.1 mm thick hot rolling A board was used. The obtained hot-rolled sheet was subjected to hot-rolled sheet annealing at 825 ° C. for 2 minutes, pickled, and then cold-rolled at a rolling reduction of 73.8 to 91.9%, and the final sheet thickness was 0.55 to 0.17 mm. Finished. This was subjected to decarburization annealing for 5 minutes in a wet hydrogen atmosphere at 830 ° C., and then subjected to finish annealing at 890 ° C. for 10 hours in dry hydrogen. Table 1 shows the relationship between the cold rolling reduction ratio and the magnetic flux density B 8 , B 100 at a magnetic field strength of 800,10000 A / m.
[0031]
[Table 1]
From Table 1, by setting the cold rolling reduction ratio in the range of 75% or more and 90% or less, the crystal direction of the steel sheet can be controlled as desired. As a result, the magnetic flux densities B 8 ≧ 1.90, B 100 ≧ 2 It can be seen that a grain-oriented electrical steel sheet having an extremely excellent magnetic flux density of 10 T can be obtained.
[0033]
【Example】
[Example 1]
A slab containing the components of Table 2 and the balance Fe and unavoidable impurities was heated and then hot rolled to obtain a hot rolled sheet having a thickness of 2.1 mm. The obtained hot-rolled sheet was subjected to hot-rolled sheet annealing at 830 ° C. for 2 minutes, then pickled, cold-rolled at 73.8 to 91.9%, and finished to 0.55 to 0.17 mm. This was subjected to decarburization annealing in a wet hydrogen atmosphere at 830 ° C. Thereafter, finish annealing was performed at 890 ° C. for 10 hours.
[0034]
[Table 2]
Table 3 shows the relationship between the cold rolling reduction ratio and the magnetic properties after finish annealing. From Table 3, when the cold rolling reduction ratio is 75 to 90%, the crystal direction of the steel sheet can be controlled as desired, and as a result, the magnetic flux densities B 8 ≧ 1.90 and B 100 ≧ 2.10T are good. It can be seen that a grain-oriented electrical steel sheet having a magnetic flux density is obtained.
[0036]
[Table 3]
[Example 2]
A slab containing the components of Table 4 and the balance Fe and unavoidable impurities was heated and then hot rolled to obtain a hot rolled sheet having a thickness of 3.0 mm. The obtained hot-rolled sheet was subjected to hot-rolled sheet annealing at 830 ° C. for 2 minutes, and then pickled to give a cold-roll of 73.3 to 91.7%, and finished to 0.80 to 0.25 mm. . This was subjected to decarburization annealing in a wet hydrogen atmosphere at 830 ° C. Thereafter, finish annealing was performed at 890 ° C. for 10 hours.
[0038]
[Table 4]
Table 5 shows the relationship between the cold rolling reduction ratio and the magnetic properties after finish annealing. From Table 5, when the cold rolling reduction ratio is 75 to 90%, the crystal direction of the steel sheet can be controlled as desired, and as a result, the magnetic flux densities B 8 ≧ 1.90 and B 100 ≧ 2.10T are good. It can be seen that a grain-oriented electrical steel sheet having a proper magnetic flux density is obtained.
[0040]
[Table 5]
[Example 3]
A slab containing the components of Table 6 and the balance Fe and inevitable impurities was heated and then hot rolled to obtain a hot rolled sheet having a thickness of 3.5 mm. The obtained hot-rolled sheet was subjected to hot-rolled sheet annealing at 800 ° C. for 90 seconds and pickled. Then, it finished to 2.1 mm by the first cold rolling. Further, this was subjected to an intermediate annealing at 830 ° C. for 90 seconds, and thereafter, this was subjected to final cold rolling at a reduction ratio of 73.8 to 91.9%, and finished to 0.55 to 0.17 mm. This was subjected to decarburization annealing in a wet hydrogen atmosphere at 830 ° C. Thereafter, finish annealing was performed at 890 ° C. for 10 hours.
[0042]
[Table 6]
Table 7 shows the relationship between the cold rolling reduction ratio and the magnetic properties after finish annealing. From Table 7, when the cold rolling reduction is 75 to 90%, the crystal direction of the steel sheet can be controlled as desired, and as a result, the magnetic flux densities B 8 ≧ 1.90, B 100 ≧ 2.10T are good. It can be seen that a grain-oriented electrical steel sheet having a proper magnetic flux density is obtained.
[0044]
[Table 7]
【The invention's effect】
Thus, according to the present invention, it is possible to manufacture a grain-oriented electrical steel sheet having a very high magnetic flux density.
Claims (1)
０．０１０％≦Ｃ≦０．１４％、
０．０１０％≦酸可溶性Ａｌ≦０．０５０％、
０．００３０％≦Ｎ≦０．０１５０％
を含有し、残部がＦｅ及び不可避的不純物からなるスラブを、加熱、熱延した後、１回以上の冷延を行って最終板厚とし、脱炭焼鈍後、Ａｃ１変態点以下の温度域で最終焼鈍する方向性電磁鋼板の製造方法であって、最終冷延圧下率を７５％以上９０％以下とし、８９０℃×１０時間の仕上げ焼鈍を行い、８００Ａ／ｍでの磁束密度：Ｂ８≧１．９０Ｔ、かつ１００００Ａ／ｍでの磁束密度：Ｂ１００≧２．１０Ｔとすることを特徴とする方向性電磁鋼板の製造方法。% By mass
0.010% ≦ C ≦ 0.14%,
0.010% ≦ acid-soluble Al ≦ 0.050%,
0.0030% ≦ N ≦ 0.0150%
A slab containing Fe and the inevitable impurities, and after heating and hot rolling, the steel sheet is subjected to cold rolling at least once to obtain a final thickness, and after decarburization annealing, a temperature range below the Ac 1 transformation point. Is a method for producing a grain-oriented electrical steel sheet that is finally annealed at a final cold rolling reduction rate of 75% or more and 90% or less , finish annealing at 890 ° C. for 10 hours , and magnetic flux density at 800 A / m: B 8 ≧ 1.90 T and magnetic flux density at 10000 A / m: B 100 ≧ 2.10 T
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35915997A JP4163773B2 (en) | 1997-12-26 | 1997-12-26 | Method for producing grain-oriented electrical steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35915997A JP4163773B2 (en) | 1997-12-26 | 1997-12-26 | Method for producing grain-oriented electrical steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11189851A JPH11189851A (en) | 1999-07-13 |
| JP4163773B2 true JP4163773B2 (en) | 2008-10-08 |
Family
ID=18463055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35915997A Expired - Fee Related JP4163773B2 (en) | 1997-12-26 | 1997-12-26 | Method for producing grain-oriented electrical steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4163773B2 (en) |
-
1997
- 1997-12-26 JP JP35915997A patent/JP4163773B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH11189851A (en) | 1999-07-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4653266B2 (en) | Manufacturing method of unidirectional electrical steel sheet | |
| JPH0688171A (en) | Production of ultrahigh magnetic flux density grain oriented silicon steel sheet | |
| KR100293140B1 (en) | Unidirectional Electronic Steel Sheet and Manufacturing Method Thereof | |
| KR100779579B1 (en) | Manufacturing method for non-oriented electrical steel sheet having low core loss and high magnetic flux density | |
| JPS631371B2 (en) | ||
| JP3656913B2 (en) | Ultra high magnetic flux density unidirectional electrical steel sheet | |
| JP3081118B2 (en) | Grain-oriented electrical steel sheet with extremely low iron loss | |
| JP4163773B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| KR950002895B1 (en) | Ultrahigh-silicon directional electrical steel sheet and production thereof | |
| JP3397277B2 (en) | Manufacturing method of ultra-low iron loss ultra-high magnetic flux density unidirectional electromagnetic steel strip | |
| JP3397293B2 (en) | Manufacturing method of ultra high magnetic flux density unidirectional electrical steel sheet | |
| JPH06256847A (en) | Manufacture of grain-oriented electrical steel sheet having excellent magnetic characteristic | |
| JP2001049351A (en) | Production of grain-oriented silicon steel sheet high in magnetic flux density | |
| JPH06212274A (en) | Production of grain-oriented silicon steel sheet having extremely low iron loss | |
| JP4261633B2 (en) | Manufacturing method of unidirectional electrical steel sheet | |
| JP3311021B2 (en) | Manufacturing method of high magnetic flux density unidirectional electrical steel sheet with low iron loss | |
| JP3561323B2 (en) | Manufacturing method of ultra high magnetic flux density unidirectional electrical steel sheet | |
| JP3546114B2 (en) | Manufacturing method of grain-oriented electrical steel sheet with high magnetic flux density | |
| JP3324044B2 (en) | Manufacturing method of ultra high magnetic flux density unidirectional electrical steel sheet | |
| JP3479984B2 (en) | Unidirectional silicon steel sheet having stable magnetic properties and method of manufacturing the same | |
| JP3397273B2 (en) | Manufacturing method for ultra-low iron loss ultra-high magnetic flux density unidirectional electrical steel sheet | |
| JPH0277526A (en) | Production of low-iron-loss grain-oriented electrical steel sheet | |
| JPH1025516A (en) | Production of grain oriented silicon steel sheet with ultrahigh magnetic flux density | |
| JP4213784B2 (en) | Manufacturing method of unidirectional electrical steel sheet | |
| JPH09118920A (en) | Stable manufacture of grain-oriented magnetic steel sheet excellent in magnetic property |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20041209 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20050809 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20051005 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070522 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070719 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080501 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080626 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20080722 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080725 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110801 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110801 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120801 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130801 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130801 Year of fee payment: 5 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130801 Year of fee payment: 5 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130801 Year of fee payment: 5 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130801 Year of fee payment: 5 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |