JPH09202925A - Production of grain-oriented silicon steel sheet with large product sheet thickness - Google Patents
Production of grain-oriented silicon steel sheet with large product sheet thicknessInfo
- Publication number
- JPH09202925A JPH09202925A JP8012023A JP1202396A JPH09202925A JP H09202925 A JPH09202925 A JP H09202925A JP 8012023 A JP8012023 A JP 8012023A JP 1202396 A JP1202396 A JP 1202396A JP H09202925 A JPH09202925 A JP H09202925A
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- Prior art keywords
- grain
- steel sheet
- annealing
- electrical steel
- hot
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、トランス等の鉄心
として使用される製品厚の厚い一方向性電磁鋼板の製造
方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a grain-oriented electrical steel sheet having a large product thickness, which is used as an iron core of a transformer or the like.
【０００２】[0002]
【従来の技術】一方向性電磁鋼板は、主にトランスその
他の電気機器の鉄心材料として使用されており、励磁特
性、鉄損特性等の磁気特性に優れていることが、機器の
小型化、エネルギー損失の減少のために要求される。励
磁特性を表す特性値として、磁場の強さ８００Ａ／ｍに
おける磁束密度Ｂ8 がＪＩＳで規格化されて通常使用さ
れる。又、エネルギー損失を示す特性値としては、周波
数５０Hzで１．７テスラー（Ｔ）まで磁化したときの鋼
板１kg当たりのエネルギー損失（鉄損）Ｗ17/50もＪＩ
Ｓで規格化されている。2. Description of the Related Art Unidirectional electrical steel sheets are mainly used as iron core materials for transformers and other electric equipment, and are excellent in magnetic characteristics such as excitation characteristics and iron loss characteristics. Required for reduced energy loss. As a characteristic value representing the excitation characteristics, magnetic flux density B 8 in the strength of 800A / m of the magnetic field standardized by JIS it is normally used. Further, as the characteristic value indicating the energy loss, the energy loss (iron loss) W 17/50 per kg of the steel sheet when magnetized at a frequency of 50 Hz to 1.7 Tesla (T) is also JI.
Standardized by S.
【０００３】磁束密度は鉄損の最大支配因子であり、一
般的に磁束密度が高い（大きい）ほど鉄損特性が良好に
なる。又、一般的に磁束密度が高くなると二次再結晶粒
が大きくなり、鉄損が悪化する場合がある。この場合
は、既に広く知られているように、磁区を制御すること
により、二次再結晶の粒径に拘らず鉄損を改善すること
ができる。[0003] The magnetic flux density is the largest controlling factor of iron loss. Generally, the higher (larger) the magnetic flux density, the better the iron loss characteristics. In general, as the magnetic flux density increases, the size of the secondary recrystallized grains increases, and iron loss may deteriorate. In this case, as already widely known, by controlling the magnetic domain, the iron loss can be improved irrespective of the grain size of the secondary recrystallization.
【０００４】この一方向性電磁鋼板は、最終仕上焼鈍工
程で二次再結晶を起こさせ、鋼板表面に｛１１０｝、圧
延方向に〈００１〉軸をもったいわゆるゴス組織を有し
ている。良好な磁気特性を得るためには、磁化容易軸で
ある〈００１〉を圧延方向に高度に揃えることが必要で
ある。このような高磁束密度一方向性電磁鋼板の製造技
術は古くから開発され、わが国ではいわゆるインヒビタ
ーとしてＭｎＳ，ＡｌＮを用いる方法（特開昭４０−１
５６４４号公報）、ＭｎＳ，ＭｎＳｅ，Ｓｂ等を用いる
方法（特開昭５１−１３４６９号公報）等がある。これ
らの場合は、熱延板段階でのインヒビターの完全固溶が
求められ、実際の熱間圧延時は鋼塊（スラブ）の加熱温
度を１３５０℃以上にすることが必要である。This unidirectional electrical steel sheet has a so-called Goss structure having {110} on the surface of the steel sheet and <001> axis in the rolling direction by causing secondary recrystallization in the final finishing annealing step. In order to obtain good magnetic properties, it is necessary that <001>, which is the axis of easy magnetization, be highly aligned in the rolling direction. The manufacturing technology of such high magnetic flux density unidirectional magnetic steel sheet has been developed for a long time, and in Japan, a method using MnS or AlN as a so-called inhibitor (Japanese Patent Laid-Open No. 40-1).
5644), a method using MnS, MnSe, Sb, and the like (Japanese Patent Application Laid-Open No. 51-13469). In these cases, complete solid solution of the inhibitor at the hot rolled sheet stage is required, and it is necessary to set the heating temperature of the steel ingot (slab) to 1350 ° C. or higher during actual hot rolling.
【０００５】この高温度の加熱には数々の不利、不便な
点がある。このため、この熱延時の鋼塊（スラブ）の加
熱温度を下げる試みが行われている。その一つを開示し
たものとして特開昭５９−５６５２２号公報がある。こ
の技術の発展として多くの発明がなされ、インヒビター
形成のために脱炭焼鈍から最終仕上焼鈍の昇温過程で窒
化を行う方法（特開昭６２−４５２８５号公報、特開昭
６０−１７９８５５号公報）、更にはストリップを走行
せしめる状態下での水素、窒素、アンモニアの混合ガス
を用いた窒化処理を行う方法（特開平２−７７５２５号
公報、特開平１−８２４００号公報、特開平３−１８０
４６０号公報、特開平１−３１７５９２号公報）が提案
された。There are a number of disadvantages and inconveniences in heating at this high temperature. For this reason, attempts have been made to lower the heating temperature of the steel ingot (slab) during hot rolling. JP-A-59-56522 discloses one of them. A number of inventions have been made as a development of this technology, and a method of performing nitridation in the process of increasing the temperature from decarburizing annealing to final finish annealing to form inhibitors (Japanese Patent Application Laid-Open Nos. 62-45285 and 60-179855). ), And a method of performing a nitriding treatment using a mixed gas of hydrogen, nitrogen and ammonia while the strip is running (JP-A-2-77525, JP-A-1-82400, JP-A-3-180).
460, JP-A-1-317592) have been proposed.
【０００６】又、脱炭焼鈍時の一次再結晶完了後から最
終仕上焼鈍時の二次再結晶完了前までの途中段階での一
次再結晶粒径を制御する方法（特開平３−２９４４２５
号公報、特開平２−９６２７５号公報、特開平２−５９
０２０号公報、特開平１−８２３９３号公報）も提案さ
れた。ところで、一方向性電磁鋼板は、主に変圧器の鉄
心として積層して使用される。特に大型のパワートラン
スは、その鉄心の積層作業は、手作業となるので、一方
向性電磁鋼板の板厚が厚い程、作業性（生産性）が向上
する。このため厚手（例えば０．４０mm超）で、磁気特
性が優れた一方向性電磁鋼板の製造が強く求められてい
た。しかし、一方向性電磁鋼板の製造においては、炭素
をある程度含有させることが従来の技術では必須であっ
た。炭素を含有させる目的は高温度（１３５０℃以上）
のスラブ加熱の場合にはスラブ加熱時の異常粒成長の
防止、一次再結晶の集合組織調整のための変態相の確
保、インヒビターの固溶量確保等がある。また、本発
明のごとく１２８０℃未満でのスラブ加熱でストリップ
を走行せしめる状態での窒化処理をする場合も上記，
の目的のため炭素をある程度含有することが求められ
ていた。一方、一方向性電磁鋼板の最終製品に炭素が３
０ppm 以上存在すると磁気時効が生じ商品価値が無くな
る。このため脱炭焼鈍工程で強制的に炭素含有量を３０
ppm 以下とする。この場合、板厚が厚いと脱炭に時間を
要し、生産性が著しく低下し、引いては、コスト高とな
る。このため現在、一方向性電磁鋼板の製品厚は０．３
５mmを最大としてＪＩＳ等で規格されている。又、炭素
含有量を減ずる方法として上記の代替として、熱延加
熱前に一度プレローリーング（ブレイクダウン）という
結晶粒を細かくする方法が採用されている。しかしこの
場合もコストアップが必然的に生じる。また、低Ｃ化に
は限界がある。A method of controlling the primary recrystallized grain size at an intermediate stage from the completion of the primary recrystallization at the time of decarburizing annealing to the completion of the secondary recrystallization at the time of final finishing annealing (Japanese Patent Laid-Open No. 3-294425).
JP, JP-A-2-96275, JP-A-2-59
020, JP-A-1-82393) have also been proposed. By the way, the unidirectional electrical steel sheets are mainly used by being laminated as an iron core of a transformer. Particularly for a large-sized power transformer, the work of stacking the iron cores is a manual work, and thus the workability (productivity) is improved as the thickness of the unidirectional electrical steel sheet is increased. Therefore, there has been a strong demand for manufacturing thick (for example, more than 0.40 mm) unidirectional electrical steel sheets with excellent magnetic properties. However, in the production of the grain-oriented electrical steel sheet, it has been essential in the prior art to incorporate carbon to some extent. The purpose of containing carbon is high temperature (1350 ° C or higher)
In the case of slab heating, there are measures such as preventing abnormal grain growth during slab heating, securing a transformation phase for adjusting the texture of primary recrystallization, and securing a solid solution amount of the inhibitor. In addition, as in the case of the present invention, the nitriding treatment in the state where the strip is run by heating the slab below 1280 ° C. is performed as described above.
It was required to contain some carbon for the purpose of. On the other hand, carbon is 3 in the final product of the grain-oriented electrical steel sheet.
If it is present at 0 ppm or more, magnetic aging will occur and the commercial value will be lost. Therefore, in the decarburization annealing process, the carbon content is forced to 30%.
It should be below ppm. In this case, if the plate thickness is thick, it takes time to decarburize, the productivity is remarkably reduced, and the cost is increased. Therefore, the product thickness of unidirectional electrical steel sheet is currently 0.3.
It is standardized in JIS etc. with a maximum of 5 mm. As a method of reducing the carbon content, as a substitute for the above, a method of once pre-rolling (breakdown) to make fine crystal grains before hot rolling and heating is adopted. However, also in this case, the cost is inevitably increased. Further, there is a limit to the reduction of C.
【０００７】また、特開平４−３２３号および特開平４
−３２４号公報においては厚手方向性電磁鋼板の熱延板
焼鈍をしない場合の熱間圧延時の条件を規定している。
もちろんこの方法によっても厚い方向性電磁鋼板は製造
可能である。この場合は、方向性電磁鋼板の製造におけ
る一次再結晶集合組織の改質のみを行なっているのであ
るが、インヒビターの調整は熱間圧延工程のみで行って
おり磁気特性の安定性及び鉄損の向上に限界があった。Further, JP-A-4-323 and JP-A-4
In Japanese Patent Laid-Open No. 324, the conditions for hot rolling of a thick grain-oriented electrical steel sheet without hot-rolled sheet annealing are specified.
Of course, a thick grain-oriented electrical steel sheet can also be manufactured by this method. In this case, only the primary recrystallization texture is modified in the production of grain-oriented electrical steel, but the inhibitor is adjusted only in the hot rolling process, and the stability of magnetic properties and iron loss There was a limit to improvement.
【０００８】[0008]
【発明が解決しようとする課題】上述したように一方向
性電磁鋼板の製造において必然的に脱炭工程が存在する
ため、厚手材（０．３０mm以上）の場合は、脱炭焼鈍前
の炭素含有量を極力減ずることがその生産性向上に重要
となる。本発明は磁気特性を確保してこの様な脱炭焼鈍
での負荷を軽減するために炭素含有量を減ずる方法を提
供するものである。As described above, the decarburization step is inevitably present in the production of the grain-oriented electrical steel sheet. Therefore, in the case of thick material (0.30 mm or more), the carbon before decarburization annealing is used. It is important to reduce the content as much as possible to improve the productivity. The present invention provides a method of reducing the carbon content in order to secure the magnetic properties and reduce the load in such decarburization annealing.
【０００９】よく知られている様に、一方向性電磁鋼板
の脱炭焼鈍工程は連続的に行なわれ次の３つの機能を有
している。すなわち、（１）一次再結晶、（２）脱炭、
（３）表面酸化層の形成の３つの機能である。これら３
つの機能をうまく働かせるためには、注意深い操業が必
要となる。本発明の様に製品厚が厚い場合は、従来
（２）と（３）を経済的に両立させることが困難であっ
た。As is well known, the decarburization annealing process of the grain-oriented electrical steel sheet is continuously performed and has the following three functions. That is, (1) primary recrystallization, (2) decarburization,
(3) It has three functions of forming a surface oxide layer. These three
Careful operation is required to make the two functions work well. When the product is thick as in the present invention, it has been difficult to economically combine the conventional methods (2) and (3).
【００１０】即ち、板厚が厚い場合は、脱炭に要する時
間が長くなる（近似的に脱炭時間は、厚みの２乗に比例
して長くなる）。一方、脱炭雰囲気（酸化性雰囲気）に
長く鋼板を滞留させると表面の酸化層が厚くなり脱炭性
が減じて残存炭素を３０ppm以下とすることは非常に困
難となる。また表面の酸化層が著しく厚くなると、２次
再結晶焼鈍後の一次皮膜（フォルステライトを主成分と
する皮膜）に欠陥が生じ商品価値が著しく減じる。この
ため炭素含有量を減ずることが必要となる。That is, when the plate thickness is large, the time required for decarburization becomes long (approximately the decarburization time becomes long in proportion to the square of the thickness). On the other hand, when the steel sheet is allowed to stay in the decarburizing atmosphere (oxidizing atmosphere) for a long time, the oxide layer on the surface becomes thick and the decarburizing property is reduced, and it becomes very difficult to reduce the residual carbon to 30 ppm or less. Further, if the oxide layer on the surface becomes extremely thick, defects will occur in the primary film (film mainly composed of forsterite) after secondary recrystallization annealing, and the commercial value will be significantly reduced. Therefore, it is necessary to reduce the carbon content.
【００１１】更に、求められることは、磁気特性のうち
磁束密度のみでなく鉄損も良好な厚手方向性電磁鋼板を
得ることを低炭素含有量素材で製造することである。Further, what is required is to produce a thick grain oriented electrical steel sheet having good magnetic loss as well as magnetic flux density among the magnetic characteristics, by manufacturing with a low carbon content material.
【００１２】[0012]
【課題を解決するための手段】本発明者らは、鋭意検討
したところ、スラブ加熱温度が１２８０℃未満で、脱炭
焼鈍後にストリップを走行せしめる状態下で窒化処理を
行なうことを主要技術とする一方向性電磁鋼板の製造方
法においては製品板厚と最終冷間圧延率をある特定範囲
とすると炭素含有量が従来より低くても良好な磁性を有
する一方向性電磁鋼板が製造可能となることを見い出し
た。Means for Solving the Problems The inventors of the present invention have made earnest studies and, as a main technique, carry out a nitriding treatment in a state where a slab heating temperature is lower than 1280 ° C. and a strip is allowed to run after decarburization annealing. In the production method of unidirectional electrical steel sheet, if the product sheet thickness and the final cold rolling rate are within certain ranges, it is possible to produce unidirectional electrical steel sheet with good magnetism even if the carbon content is lower than before. Found out.
【００１３】そもそも、一方向性電磁鋼板の製造におい
て良好な磁気特性（方向性の良好なＧｏｓｓ方位を有す
る２次再結晶集合組織）を得るためには、脱炭焼鈍後の
一次再結晶集合の適正化及びインヒビター強度の確保が
必要である。従来から一方向性電磁鋼板の製造において
一次再結晶集合組織を適正化するためには、熱間圧延後
最終冷間圧延の間にある程度の変態相が必要とされてい
た。このために炭素を含有させている。ところが、１２
８０℃未満のスラブ加熱法においては一次再結晶集合組
織の適正化の程度が少なくても良いことを見い出した。
この適正化程度は定量的には原勢らの対応粒界理論（例
えば特公平７−２６１５５、日本金属学会誌 第５９
巻、第９号（１９９５）９１７−９２４）によって評価
できる。即ちＧｏｓｓ方位粒（｛１１０｝〈０１１〉）
とΣ９対応方位粒がある少量でも存在しその値が全Σ９
方位関係の分布の中で一番大きい（強い）と良好なＧｏ
ｓｓ方位が２次再結晶する。しかし、このＧｏｓｓ方位
発現の安定性及びシャープさはインヒビターの強度に依
存する。In the first place, in order to obtain good magnetic properties (secondary recrystallization texture having a good Goss orientation with good directionality) in the production of grain-oriented electrical steel sheet, the primary recrystallization aggregation after decarburization annealing is required. It is necessary to optimize and secure inhibitor strength. Conventionally, in order to optimize the primary recrystallization texture in the production of grain-oriented electrical steel sheets, a certain degree of transformation phase was required during the final cold rolling after the hot rolling. For this reason, carbon is included. However, 12
It has been found that in the slab heating method of less than 80 ° C., the degree of optimization of the primary recrystallization texture may be small.
Quantitatively, this optimization degree corresponds to the grain boundary theory of Harase et al. (Eg, Japanese Examined Patent Publication 7-26155, The Japan Institute of Metals, No. 59).
Vol. 9, No. 9 (1995) 917-924). That is, Goss oriented grains ({110} <011>)
And Σ9 corresponding orientation grains exist even in a small amount, and the value is all Σ9
Largest (strong) and good Go in the azimuth distribution
Secondary recrystallization occurs in the ss orientation. However, the stability and sharpness of this Goss orientation expression depend on the strength of the inhibitor.
【００１４】本発明による方法では、このインヒビター
強度を任意にストリップ窒化として制御できるため良好
なＧｏｓｓ方位粒のみを選択的に発現できることを見い
出した。このＧｏｓｓ方位粒に対するΣ９値を全分布で
最大とする方法としては、主に冷間圧延前集合組織、粒
サイズ、及び冷間圧延率があるがこのうち冷間圧延率が
最大影響因子であるのでこれを規定することによって製
品板厚の厚い一方向性電磁鋼板の製造が可能になったも
のである。In the method according to the present invention, it has been found that the inhibitor strength can be arbitrarily controlled as strip nitriding so that only good Goss-oriented grains can be selectively expressed. As a method for maximizing the Σ9 value for this Goss-oriented grain in the entire distribution, there are mainly texture before cold rolling, grain size, and cold rolling rate, of which the cold rolling rate is the most influential factor. Therefore, by defining this, it becomes possible to manufacture a grain-oriented electrical steel sheet having a thick product sheet.
【００１５】その要旨は以下のとおりである。 （１）重量比でＣ：０．０１０〜０．０４０％、Ｓｉ：
２．５〜４．０％、酸可溶性Ａｌ：０．０２０〜０．０
４０％、Ｎ：０．００５〜０．０１０％、Ｓ，Ｓｅの少
なくとも１種を０．００５〜０．０１５％、Ｍｎ：０．
０５〜０．８％、残部がＦｅ及び不可避的不純物からな
るスラブを１２８０℃未満の温度で加熱し、熱延を行な
い、熱延板焼鈍を行ない、中間焼鈍を挟む一回以上の冷
延を行ない、脱炭焼鈍後ストリップを走行せしめる状態
下で水素、窒素、アンモニアの混合ガス中で窒化処理を
行ない、次いでＭｇＯを主成分とする焼鈍分離剤を塗布
して最終仕上焼鈍を施す一方向性電磁鋼板の製造方法に
おいて、製品厚（ｔ：mm）を０．３０mm≦ｔ≦０．６５
mmとし最終冷間圧延率：Ｒ（％）をThe summary is as follows. (1) C: 0.010 to 0.040% by weight, Si:
2.5-4.0%, acid-soluble Al: 0.020-0.0
40%, N: 0.005-0.010%, 0.005 to 0.015% of at least one of S and Se, Mn: 0.
A slab consisting of 05 to 0.8% and the balance of Fe and unavoidable impurities is heated at a temperature of less than 1280 ° C. to perform hot rolling, hot-rolled sheet annealing, and one or more cold rollings with intermediate annealing. One-way property of performing final anneal by performing nitriding treatment in a mixed gas of hydrogen, nitrogen, and ammonia under the condition of running the strip after decarburization annealing, and then applying an annealing separator containing MgO as a main component. In the method of manufacturing an electromagnetic steel sheet, the product thickness (t: mm) is set to 0.30 mm ≦ t ≦ 0.65
mm and final cold rolling rate: R (%)
【００１６】[0016]
【数２】 [Equation 2]
【００１７】とすることを特徴とする製品板厚が厚い一
方向性電磁鋼板の製造方法。 （２）更に、上記（１）の鋼成分組成に加え、Ｓｎ，Ｓ
ｂ，Ｃｒ，Ｐの少くとも１種を０．０２〜０．３％含有
させることを特徴とする製品板厚が厚い一方向性電磁鋼
板の製造方法。 （３）更に、上記（１），（２）の鋼成分組成に加え、
Ｃｕを０．０３〜０．３０％含有させることを特徴とす
る製品板厚が厚い一方向性電磁鋼板の製造方法。 （４）更に、上記（１），（２），（３）の鋼成分組成
に加え、Ｎｉを０．０３〜０．３％含有させることを特
徴とする製品板厚が厚い一方向性電磁鋼板の製造方法。A method for producing a grain-oriented electrical steel sheet having a large product thickness, characterized in that (2) Further, in addition to the steel composition of the above (1), Sn, S
A method for producing a grain-oriented electrical steel sheet having a large product thickness, which contains 0.02 to 0.3% of at least one of b, Cr and P. (3) Further, in addition to the steel composition of the above (1) and (2),
A method for producing a grain-oriented electrical steel sheet having a large product thickness, characterized by containing Cu in an amount of 0.03 to 0.30%. (4) Furthermore, in addition to the steel composition of the above (1), (2), and (3), Ni is contained in an amount of 0.03 to 0.3%. Steel plate manufacturing method.
【００１８】[0018]
【発明の実施の形態】以下に本発明を詳細に説明する。
まず本発明において板厚を制限する理由を述べる。製品
板厚が０．３０mm未満の場合炭素含有量を０．０４０％
以上としても０．０６０％以下であれば、脱炭焼鈍にお
いて３０ppm 以下の炭素までの脱炭は律速的でなく表面
酸化層形成が律速的であり、低炭素とするメリットは少
ない。このため板厚は、０．３０mm以上とする。また板
厚が０．３０mm未満であれば、炭素量が少ないと一次再
結晶集合組織が充分に適正にしないと、２次再結晶焼鈍
時のインヒビター（主にＡｌＮ）の劣化度が速くなり良
好なＧｏｓｓ方位粒が得られなくなる。もちろん、２次
再結晶時の雰囲気を制御してインヒビターの分解を抑制
し、良好なＧｏｓｓ方位粒を得ることは可能であるが、
この場合フォルステライトを主成分とする一次皮膜に欠
陥が多発して歩留が著しく低下する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
First, the reason for limiting the plate thickness in the present invention will be described. When the product plate thickness is less than 0.30 mm, the carbon content is 0.040%
Even if the content is 0.060% or less, decarburization up to 30 ppm or less of carbon in decarburization annealing is not rate-determining but surface oxide layer formation is rate-determining, and there is little merit in reducing carbon. Therefore, the plate thickness is 0.30 mm or more. Further, if the plate thickness is less than 0.30 mm, if the carbon content is small and the primary recrystallization texture is not adequately adequate, the degree of deterioration of the inhibitor (mainly AlN) during secondary recrystallization annealing will be fast and good. No good Goss-oriented grains can be obtained. Of course, it is possible to control the atmosphere during the secondary recrystallization and suppress the decomposition of the inhibitor to obtain good Goss-oriented grains.
In this case, many defects occur in the primary film mainly composed of forsterite, and the yield is remarkably reduced.
【００１９】一方、上限の０．６５mmは、これ以上の板
厚では、生産性を確保するためには炭素含有量を０．０
１０％未満としなければならないためである。炭素含有
量を０．０１０％未満とすると、フォルステライトを主
成分とする一次皮膜の形成を良好に行なわしめてかつ良
好なＧｏｓｓ方位の２次再結晶を安定化することは困難
である。On the other hand, the upper limit of 0.65 mm has a carbon content of 0.05 in order to secure productivity with a plate thickness larger than this.
This is because it must be less than 10%. When the carbon content is less than 0.010%, it is difficult to favorably form the primary film containing forsterite as a main component and to stabilize the secondary recrystallization having good Goss orientation.
【００２０】次に、本発明において出発材とする電磁鋼
スラブの成分組成の限定理由は、以下のとおりである。
Ｃは、０．０１０〜０．０４０％とした。０．０１０％
未満の場合は前述した。また０．０４０％を越えると脱
炭工程での生産性が著しく阻害され本発明の目的から外
れる。Next, the reasons for limiting the component composition of the electromagnetic steel slab used as the starting material in the present invention are as follows.
C was set to 0.010 to 0.040%. 0.010%
If less than the above, it was described above. On the other hand, if it exceeds 0.040%, the productivity in the decarburization step is significantly impaired, which is outside the scope of the present invention.
【００２１】Ｓｉはその含有量が２．５％未満になる
と、良好な鉄損が得られない。また４．０％を超える
と、脆性のために冷間圧延等室温での鋼板処理が困難に
なる。Ｓ及びＳｅは、０．０１５％以下、望ましくは
０．０１３％以下である。１２８０℃以下のスラブ加熱
温度で熱延板を製造し、その後熱延板焼鈍、冷間圧延の
後での、ストリップ窒化等による脱炭焼鈍工程以降のイ
ンヒビターの作り込みで製造する一方向性電磁鋼板で
は、多量のＳ，Ｓｅは一次再結晶粒の粒成長を妨げ有害
であるためである。０．００５％未満では、熱延での操
業上の不可避的変動要素（スキッド上及び間の温度履歴
差、圧延速度の加速による熱延温度の変動等）により、
一次再結晶粒の粒成長に場所的変動が生じ易くなり工業
的に安定的に製品が製造できない。If the Si content is less than 2.5%, good iron loss cannot be obtained. On the other hand, if it exceeds 4.0%, it becomes difficult to perform steel sheet processing such as cold rolling at room temperature due to brittleness. S and Se are 0.015% or less, desirably 0.013% or less. One-way electromagnetic produced by manufacturing a hot-rolled sheet at a slab heating temperature of 1280 ° C. or lower, and then making an inhibitor after the decarburization annealing step such as strip nitriding after hot-rolled sheet annealing and cold rolling. This is because in the steel sheet, a large amount of S and Se hinders the grain growth of the primary recrystallized grains and is harmful. If it is less than 0.005%, due to unavoidable fluctuation factors in operation in hot rolling (temperature history difference on and between skids, fluctuation of hot rolling temperature due to acceleration of rolling speed, etc.),
Since the variation in the grain growth of the primary recrystallized grains is likely to occur, the product cannot be manufactured industrially stably.
【００２２】ＡｌはＮと結合してＡｌＮを形成するが、
本発明においては、後工程即ち一次再結晶完了後に鋼を
窒化することにより（Ａｌ，Ｓｉ）Ｎを形成せしめるこ
とを必須としているから、フリーのＡｌが一定量以上必
要である。そのため、ｓｏｌ．Ａｌとして０．０２０〜
０．０４０％添加する。Ｍｎは、その含有量が少な過ぎ
ると二次再結晶が不安定となり、一方、多過ぎると高い
磁束密度をもつ製品を得難くなる。適正な含有量は０．
０５〜０．８％である。好ましくは、０．０７０〜０．
３％である。Al combines with N to form AlN,
In the present invention, since it is essential to form (Al, Si) N by nitriding the steel after the post-process, ie, after the completion of the primary recrystallization, a certain amount of free Al is required. Therefore, sol. 0.020 or more as Al
Add 0.040%. If the content of Mn is too small, secondary recrystallization becomes unstable, while if it is too large, it becomes difficult to obtain a product having a high magnetic flux density. The appropriate content is 0.
05 to 0.8%. Preferably, 0.070-0.0.
3%.
【００２３】Ｎは０．００５％未満では二次再結晶粒の
発達が悪くなる。一方０．０１０％を超えるとブリスタ
ーと呼ばれる鋼板のふくれが発生する。Ｐは、一次再結
晶集合組織を改善する効果が報告されている。低Ｐで
は、この効果が少なく、また製鋼コスト的にコストアッ
プになるので下限は０．０２％とする。上限について
は、０．３０％を超えるとＰは粒界偏析して脆性破壊を
起しやすくなり、工業的な生産が困難になる。このため
上限を０．３０％とする。If N is less than 0.005%, the development of secondary recrystallized grains becomes poor. On the other hand, when it exceeds 0.010%, swelling of steel plate called blister occurs. It has been reported that P improves the primary recrystallization texture. At a low P, this effect is small and the cost of steelmaking increases, so the lower limit is made 0.02%. With respect to the upper limit, if it exceeds 0.30%, P segregates at the grain boundary and brittle fracture is likely to occur, and industrial production becomes difficult. Therefore, the upper limit is set to 0.30%.
【００２４】Ｓｎ，Ｓｂは従来からいわれている如く、
一次再結晶集合組織において｛１１０｝〈００１〉方位
粒を増加させる効果があるとともに、硫化物を均一に析
出する効果がある。従って、本発明では、Ｃｕ−Ｓ，Ｍ
ｎ−Ｓの如き硫化物の析出を制御する効果が増長され
る。更に、Ｓｎ，Ｓｂを多く添加すると、脱炭焼鈍時の
酸化がされ難く、また一次再結晶粒成長し難くなる傾向
がある。このため、脱炭焼鈍温度を従来の８２０〜８４
０℃より２０℃程度上げざるを得ない。このことは、一
方向性電磁鋼板の一次被膜形成を容易ならしめる方向で
ある。また、Ｓｂ，Ｓｎ添加により二次再結晶粒径が小
さくなるため、添加なしと比べて鉄損（特に低磁場鉄
損）が良好となる。一方、Ｓｂ又はＳｎが０．０２％未
満であると、二次再結晶粒があまり小さくならない。ま
た、Ｓｂ又はＳｎが０．３０％を超えると、脱炭焼鈍後
の窒化処理が困難となり、工業生産に適していない。Sn and Sb are, as has been conventionally said,
In the primary recrystallization texture, it has an effect of increasing {110} <001> oriented grains and an effect of uniformly precipitating sulfide. Therefore, in the present invention, Cu-S, M
The effect of controlling the precipitation of sulfides such as n-S is enhanced. Furthermore, when Sn and Sb are added in a large amount, there is a tendency that oxidation during decarburization annealing is hardly performed and primary recrystallized grains grow hardly. For this reason, the decarburization annealing temperature is set to the conventional 820-84.
There is no choice but to raise it by 20 ° C from 0 ° C. This is a direction that facilitates the formation of the primary coating of the grain-oriented electrical steel sheet. In addition, since the secondary recrystallized grain size is reduced by adding Sb and Sn, iron loss (particularly, low magnetic field iron loss) is improved as compared with no addition. On the other hand, when Sb or Sn is less than 0.02%, the secondary recrystallized grains do not become too small. On the other hand, when Sb or Sn exceeds 0.30%, nitriding treatment after decarburizing annealing becomes difficult, which is not suitable for industrial production.
【００２５】Ｃｒは、フォルステライト皮膜形成に必要
な脱炭焼鈍後の酸素量を確保するために添加される。
０．０２％より少ないと酸素量が極端に少なくなる。ま
た０．３０％を超えると酸素量が極端に増加し、良好な
フォルステライトが形成されなくなる。また磁束密度も
低下する。Ｃｕが０．０３％未満であると効果が少な
い。また０．５％を超えると、Ｃｕ−Ｓの析出物が粗大
化して、効果が減じる。更に、熱間圧延時に、いわゆる
“Ｃｕヘゲ”という疵の発生頻度が急激に増大する。好
ましくは、０．０５〜０．１０％である。Cr is added to secure the amount of oxygen after decarburization annealing necessary for forming a forsterite film.
If it is less than 0.02%, the amount of oxygen becomes extremely small. On the other hand, if it exceeds 0.30%, the amount of oxygen increases extremely, and good forsterite is not formed. Also, the magnetic flux density decreases. If Cu is less than 0.03%, the effect is small. On the other hand, if it exceeds 0.5%, Cu-S precipitates are coarsened and the effect is reduced. Further, during hot rolling, the frequency of occurrence of so-called "Cu hegging" defects sharply increases. Preferably, it is 0.05 to 0.10%.
【００２６】Ｎｉは０．０３％未満だと効果が少なく
０．３％を超えても特開平５−３０６４１０号公報に示
されているように効果はあるが、高価となる。このため
０．３０％を上限とする。ＣｒとＮｉの添加は、本発明
の効果を更に向上させるものであり、コスト的に見合う
量だけの添加で良い。次に熱延板焼鈍の必要性について
述べる。既に述べた如く、特開平４−３２３号公報およ
び特開平４−３２４号公報においては、熱延板焼鈍を施
こさない場合の熱延条件を規定している。この場合、熱
延で、熱延板焼鈍を代替させている。しかしこの場合、
一次再結晶集合組織的にはＧｏｓｓ方位が少なく、対応
粒界理論によると最終製品の粒径が大きくなり鉄損が劣
る傾向がある。一次再結晶集合組織でのＧｏｓｓ方位粒
の量を確保し、最終製品の粒径を小さくし、鉄損を向上
させるのに有効な手段は、熱延板焼鈍を行なうことであ
る。事実、上述の両特許公報においては磁束密度は向上
するとの記載が有るが、鉄損向上に関する記載はない。If Ni is less than 0.03%, the effect is small, and if it exceeds 0.3%, it is effective as shown in JP-A-5-306410, but it becomes expensive. Therefore, the upper limit is 0.30%. The addition of Cr and Ni further improves the effect of the present invention, and may be added in amounts that are commensurate with cost. Next, the necessity of annealing the hot rolled sheet will be described. As described above, JP-A-4-323 and JP-A-4-324 define the hot rolling conditions when hot-rolled sheet annealing is not performed. In this case, hot rolling substitutes for hot rolled sheet annealing. But in this case,
The primary recrystallization texture has a small Goss orientation, and according to the corresponding grain boundary theory, the grain size of the final product tends to be large and the iron loss tends to be poor. An effective means for securing the amount of Goss-oriented grains in the primary recrystallization texture, reducing the grain size of the final product, and improving iron loss is to perform hot-rolled sheet annealing. In fact, the above-mentioned patent publications both describe that the magnetic flux density is improved, but there is no description relating to the improvement of iron loss.
【００２７】そして、熱延板焼鈍の効果は、以下に述べ
る冷間圧延の圧下率の特定の効果との相まって、厚手の
方向性電磁鋼板において磁気特性（特に鉄損値）向上と
いう格別の効果をもたらすのである。次に冷延圧下率の
範囲について図１および図２に基づいて述べる。図１は
請求項１の場合の製品板厚（mm）と最終冷間圧延率
（％）の関係を示したものである。この図１で◎印は磁
束密度（Ｂ8 ）が１．８８Ｔ以上、○印はＢ 8 ≧１．８
０Ｔ、△印はＢ8 ＜１．８０Ｔの領域を示す。また×印
は、２次再結晶不良が発生した領域である。本発明にお
いてはＢ8 ≧１．８０Ｔを磁気特性良好領域としてい
る。この様に製品厚が厚くなる程、磁性良好の最終冷間
圧下率の範囲が広がっているのは、一次再結晶集合組織
があまり良好でなくても、２次再結晶焼鈍時のインヒビ
ターの劣化の進行が遅いためである。この上下限を示す
式がThe effect of hot-rolled sheet annealing will be described below.
Coupled with the specific effect of cold rolling reduction,
Improves magnetic properties (especially iron loss value) in grain-oriented electrical steel
It has a special effect. Next, the cold rolling reduction
The range will be described based on FIGS. 1 and 2. Figure 1
Product thickness (mm) and final cold rolling rate in the case of claim 1
(%) Is shown. In Fig. 1, the ◎ mark indicates magnetism.
Bundle density (B8) Is 1.88T or more, ○ indicates B 8≧ 1.8
0T, △ mark is B8A region of <1.80T is shown. Mark x
Is an area where a secondary recrystallization defect occurs. In the present invention
Then B8≧ 1.80T is regarded as a region with good magnetic characteristics
You. In this way, the thicker the product, the better the final cold
The range of rolling reduction is widening because of the primary recrystallization texture.
Even if the quality is not very good, the
This is because the deterioration of the target is slow. Show the upper and lower limits
The expression is
【００２８】[0028]
【数３】 (Equation 3)
【００２９】である。Is as follows.
【００３０】[0030]
【実施例】次に本発明の実施例を示す。 〈実施例１〉表１に示す成分の鋼塊を通常の方法で製造
し１１００〜１１５０℃でスラブを加熱後、通常の熱延
で熱延板厚１．４〜６．０mmに仕上げた。その後１１２
０℃×２分の熱延板焼鈍を行ない、酸洗後１８０〜２２
０℃で最低２パスの温間圧延を行なって０．２２〜０．
６０mmに冷間圧延した。その後８２０℃〜８４０℃で、
Ｎ2 ：２５％、Ｈ2 ：７５％の雰囲気ガス中で、露点６
２℃で７０秒〜１５０秒の脱炭一次再結晶焼鈍を行なっ
た。Next, examples of the present invention will be described. <Example 1> Steel ingots having the components shown in Table 1 were manufactured by an ordinary method, and after heating the slab at 1100 to 1150 ° C, the hot rolled sheet was finished by ordinary hot rolling to have a hot rolled sheet thickness of 1.4 to 6.0 mm. Then 112
Annealed hot-rolled sheet for 2 minutes at 0 ° C, 180-22 after pickling
0.22-0.2 after warm rolling at 0 ° C. for at least 2 passes.
Cold rolled to 60 mm. After that, at 820 ° C to 840 ° C,
N 2 : 25%, H 2 : 75% in atmosphere gas, dew point 6
Decarburization primary recrystallization annealing was performed at 2 ° C. for 70 seconds to 150 seconds.
【００３１】その後、全窒素含有量を１９５〜２１０pp
m とするストリップ窒化処理を行ないＭｇＯを主成分と
する焼鈍分離材を塗布し、仕上焼鈍を行なった。この仕
上焼鈍は１０〜２０℃／時間で昇温し、雰囲気は、
Ｎ2 ：２５％、Ｈ2 ：７５％であった。その後１２００
℃で２０時間、Ｈ2 ：１００％の純化焼鈍を行なった。
その後、通常用いられる張力コーティングの塗布と平滑
化処理を行なった。その結果を表２に示す。Then, the total nitrogen content is adjusted to 195 to 210 pp.
m, a strip nitriding treatment was performed, an annealing separator containing MgO as a main component was applied, and finish annealing was performed. In this finish annealing, the temperature is raised at 10 to 20 ° C./hour, and the atmosphere is
N 2 : 25%, H 2 : 75%. Then 1200
A purification annealing of H 2 : 100% was performed at 20 ° C. for 20 hours.
Thereafter, application of a commonly used tension coating and smoothing treatment were performed. Table 2 shows the results.
【００３２】[0032]
【表１】 [Table 1]
【００３３】[0033]
【表２】 [Table 2]
【００３４】[0034]
【発明の効果】従来ＧＯの製造では、変態相確保のた
め、Ｃを幾分か含有する必要がある。このため製品板厚
が厚いものは、脱炭に時間が掛りコスト高である。本発
明では、Ｃ含有量を減じて、コストダウンが可能とな
る。In the conventional GO production, it is necessary to contain some C in order to secure the transformation phase. For this reason, a product having a large thickness requires a long time for decarburization and is costly. In the present invention, it is possible to reduce the cost by reducing the C content.
【図１】図１は、本発明で熱延板焼鈍を行った場合の製
品厚と最終冷間圧下率との関係を示す図である。FIG. 1 is a diagram showing a relationship between a product thickness and a final cold reduction when a hot rolled sheet is annealed in the present invention.
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成８年４月１０日[Submission date] April 10, 1996
【手続補正１】[Procedure amendment 1]
【補正対象書類名】図面[Document name to be amended] Drawing
【補正対象項目名】図１[Correction target item name] Fig. 1
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【図１】 FIG.
フロントページの続き (72)発明者 北河 久和 福岡県北九州市戸畑区飛幡町１−１ 新日 本製鐵株式会社八幡製鐵所内 (72)発明者 黒木 克郎 福岡県北九州市戸畑区大字中原46番地の59 日鐵プラント設計株式会社内Front page continued (72) Inventor Hisawa Kita 1-1 1-1 Hibahata-cho, Tobata-ku, Kitakyushu, Fukuoka Prefecture (72) Inside Hachiman Works, Nippon Steel Corporation (72) Katsuro Kuroki, Nakahara 46, Tobata-ku, Kitakyushu, Fukuoka Address of 59 Nittetsu Plant Design Co., Ltd.
Claims (4)
％、 Ｓｉ：２．５〜４．０％、 酸可溶性Ａｌ：０．０２０〜０．０４０％、 Ｎ：０．００５〜０．０１０％、 Ｓ，Ｓｅの少なくとも１種を０．００５〜０．０１５
％、 Ｍｎ：０．０５〜０．８％、 残部がＦｅ及び不可避的不純物からなるスラブを１２８
０℃未満の温度で加熱し、熱延を行ない、熱延板焼鈍を
行ない、中間焼鈍を挟む一回以上の冷延を行ない、脱炭
焼鈍後ストリップを走行せしめる状態下で水素、窒素、
アンモニアの混合ガス中で窒化処理を行ない、次いでＭ
ｇＯを主成分とする焼鈍分離剤を塗布して最終仕上焼鈍
を施す一方向性電磁鋼板の製造方法において、製品厚
（ｔ：mm）を０．３０mm≦ｔ≦０．６５mmとし最終冷間
圧延率：Ｒ（％）を 【数１】 とすることを特徴とする製品板厚が厚い一方向性電磁鋼
板の製造方法。1. A weight ratio of C: 0.010 to 0.040.
%, Si: 2.5-4.0%, Acid-soluble Al: 0.020-0.040%, N: 0.005-0.010%, S, Se at least 1 type is 0.005-0. .015
%, Mn: 0.05 to 0.8%, 128 slabs with the balance Fe and unavoidable impurities
Heating at a temperature of less than 0 ° C., hot rolling, hot-rolled sheet annealing, cold rolling at least once with intermediate annealing sandwiched between hydrogen, nitrogen, and decarburization annealing, and running strips.
Nitriding is performed in a mixed gas of ammonia, then M
In the method for producing a grain-oriented electrical steel sheet in which an annealing separator containing gO as a main component is applied and final finishing annealing is performed, the product thickness (t: mm) is set to 0.30 mm ≤ t ≤ 0.65 mm and the final cold rolling is performed. Rate: R (%) A method for producing a grain-oriented electrical steel sheet having a large product thickness, characterized by:
１種を０．０２〜０．３０％含有させることを特徴とす
る請求項１記載の製品板厚が厚い一方向性電磁鋼板の製
造方法。2. The production of a grain-oriented electrical steel sheet having a large product thickness according to claim 1, further containing 0.02 to 0.30% of at least one of Sn, Sb, Cr and P. Method.
せることを特徴とする請求項１、又は２記載の製品板厚
が厚い一方向性電磁鋼板の製造方法。3. The method for producing a grain-oriented electrical steel sheet having a large product sheet thickness according to claim 1, further comprising 0.03 to 0.30% Cu.
せることを特徴とする請求項１，２、又は３記載の製品
板厚が厚い一方向性電磁鋼板の製造方法。4. The method for producing a grain-oriented electrical steel sheet according to claim 1, 2 or 3, further comprising 0.03 to 0.3% of Ni.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01202396A JP3507232B2 (en) | 1996-01-26 | 1996-01-26 | Manufacturing method of unidirectional electrical steel sheet with large product thickness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01202396A JP3507232B2 (en) | 1996-01-26 | 1996-01-26 | Manufacturing method of unidirectional electrical steel sheet with large product thickness |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09202925A true JPH09202925A (en) | 1997-08-05 |
| JP3507232B2 JP3507232B2 (en) | 2004-03-15 |
Family
ID=11794014
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP01202396A Expired - Fee Related JP3507232B2 (en) | 1996-01-26 | 1996-01-26 | Manufacturing method of unidirectional electrical steel sheet with large product thickness |
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| JP (1) | JP3507232B2 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5956522A (en) * | 1982-09-24 | 1984-04-02 | Nippon Steel Corp | Manufacture of anisotropic electrical steel plate with improved iron loss |
| JPS6245285A (en) * | 1985-08-23 | 1987-02-27 | Hitachi Ltd | Video signal processing circuit |
| JPH0277525A (en) * | 1988-04-25 | 1990-03-16 | Nippon Steel Corp | Production of grain-oriented electrical steel sheet having excellent magnetic characteristic and film characteristic |
| JPH03294425A (en) * | 1990-04-13 | 1991-12-25 | Nippon Steel Corp | Production of grain-oriented silicon steel sheet excellent in magnetic property |
-
1996
- 1996-01-26 JP JP01202396A patent/JP3507232B2/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5956522A (en) * | 1982-09-24 | 1984-04-02 | Nippon Steel Corp | Manufacture of anisotropic electrical steel plate with improved iron loss |
| JPS6245285A (en) * | 1985-08-23 | 1987-02-27 | Hitachi Ltd | Video signal processing circuit |
| JPH0277525A (en) * | 1988-04-25 | 1990-03-16 | Nippon Steel Corp | Production of grain-oriented electrical steel sheet having excellent magnetic characteristic and film characteristic |
| JPH03294425A (en) * | 1990-04-13 | 1991-12-25 | Nippon Steel Corp | Production of grain-oriented silicon steel sheet excellent in magnetic property |
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| Publication number | Publication date |
|---|---|
| JP3507232B2 (en) | 2004-03-15 |
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