JPH07138643A - Production of grain-oriented electrical steel sheet excellent in magnetic property - Google Patents
Production of grain-oriented electrical steel sheet excellent in magnetic propertyInfo
- Publication number
- JPH07138643A JPH07138643A JP28667093A JP28667093A JPH07138643A JP H07138643 A JPH07138643 A JP H07138643A JP 28667093 A JP28667093 A JP 28667093A JP 28667093 A JP28667093 A JP 28667093A JP H07138643 A JPH07138643 A JP H07138643A
- Authority
- JP
- Japan
- Prior art keywords
- annealing
- hot
- hot rolling
- 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.)
- Withdrawn
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Manufacturing Of Steel Electrode Plates (AREA)
- Soft Magnetic Materials (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、トランス等の鉄心とし
て使用される磁気特性の優れた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 producing a grain-oriented electrical steel sheet having excellent magnetic properties, 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要求され
る。励磁特性を表わす数値としては、通常磁場の強さ8
00A/m における磁束密度B8が使用される。また、鉄
損特性を表わす数値としては、周波数50Hzで1.7テ
スラー(T)まで磁化した時の1kg当りの鉄損W17/15
を使用している。磁束密度は、鉄損特性の最大支配因子
であり、一般的にいって磁束密度が高いほど鉄損特性が
良好になる。なお、一般的に磁束密度を高くすると二次
再結晶粒が大きくなり、鉄損特性が不良となる場合があ
る。これに対しては、磁区制御により、二次再結晶粒の
粒径に拘らず、鉄損特性の改善をすることができる。2. Description of the Related Art Unidirectional magnetic steel sheets are mainly used as iron core materials for transformers and other electrical equipment, and are required to have excellent magnetic characteristics such as excitation characteristics and iron loss characteristics. As a numerical value showing the excitation characteristic, the strength of a normal magnetic field is 8
A magnetic flux density B 8 at 00 A / m is used. In addition, as a numerical value showing the iron loss characteristic, the iron loss per 1 kg when magnetized to 1.7 Tesler (T) at a frequency of 50 Hz is W 17/15.
Are using. The magnetic flux density is the most dominant factor of the iron loss characteristics, and generally speaking, the higher the magnetic flux density, the better the iron loss characteristics. Generally, when the magnetic flux density is increased, the secondary recrystallized grains become large, which may result in poor iron loss characteristics. On the other hand, by controlling the magnetic domains, the iron loss characteristics can be improved regardless of the grain size of the secondary recrystallized grains.
【0003】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、鋼板面に{110}、圧延
方向に〈001〉軸を持ったいわゆるゴス組織を発達さ
せることにより、製造されている。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。This unidirectional electrical steel sheet undergoes secondary recrystallization in the final finishing annealing step to develop a so-called Goss structure having {110} on the steel sheet surface and <001> axis in the rolling direction. Being manufactured. In order to obtain good magnetic properties, it is necessary to highly align <001>, which is the easy magnetization axis, in the rolling direction.
【0004】このような高磁束密度一方向性電磁鋼板の
製造技術として代表的なものに特公昭40−15644
号公報及び特公昭51−13469号公報記載の方法が
ある。前者においては主なインヒビターとしてMnS及
びAlNを、後者ではMnS,MnSe,Sb等を用い
ている。従って現在の技術においてはこれらのインヒビ
ターとして機能する析出物の大きさ、形態及び分散状態
を適正に制御することが不可欠である。MnSに関して
いえば、現在の工程では熱延前のスラブ加熱時にMnS
を一旦完全固溶させた後、熱延時に析出する方法がとら
れている。A typical technique for producing such a high magnetic flux density unidirectional electrical steel sheet is Japanese Patent Publication No. 40-15644.
There is a method described in JP-B No. 51-13469. In the former, MnS and AlN are used as main inhibitors, and in the latter, MnS, MnSe, Sb, etc. are used. Therefore, in the current technology, it is essential to appropriately control the size, morphology and dispersion state of the precipitates that function as these inhibitors. Speaking of MnS, in the current process, MnS is generated when the slab is heated before hot rolling.
A method is used in which the solid solution is once completely dissolved and then precipitated during hot rolling.
【0005】二次再結晶に必要な量のMnSを完全固溶
するためには1400℃程度の温度が必要である。これ
は普通鋼のスラブ加熱温度に比べて200℃以上も高
く、この高温スラブ加熱処理には、1)方向性電磁鋼専
用の高温スラブ加熱炉が必要、2)加熱炉のエネルギー
原単位が高い、3)溶融スケール量が増大し、いわゆる
ノロかき出し等に見られるように操業上の悪影響が大き
い。A temperature of about 1400 ° C. is required to completely dissolve the required amount of MnS for secondary recrystallization. This is higher than the slab heating temperature of ordinary steel by 200 ° C or more, and this high-temperature slab heating treatment requires 1) a high-temperature slab heating furnace exclusively for grain-oriented electrical steel, and 2) a high energy consumption rate of the heating furnace. 3) The amount of molten scale increases, and the adverse effect on operation is large, as seen in so-called shaving.
【0006】このような問題点を回避するためにはスラ
ブ加熱温度を普通鋼並に下げればよいわけであるが、こ
のことは同時にインヒビターとして有効なMnSの量を
少なくするかあるいは全く用いないことを意味し、必然
的に二次再結晶の不安定化をもたらす。このため低温ス
ラブ加熱化を実現するためには何らかの形でMnS以外
の析出物等によりインヒビターを強化し、仕上焼鈍時の
正常粒成長の抑制を十分にする必要がある。In order to avoid such problems, the slab heating temperature should be lowered to the same level as that of ordinary steel, but at the same time, the amount of MnS effective as an inhibitor should be reduced or not used at all. Means that the destabilization of the secondary recrystallization is inevitably brought about. Therefore, in order to realize low-temperature slab heating, it is necessary to strengthen the inhibitor in some form with precipitates other than MnS to sufficiently suppress normal grain growth during finish annealing.
【0007】このようなインヒビターとしては硫化物の
他、窒化物、酸化物及び粒界析出元素等が考えられ、公
知の技術として例えば次のようなものがあげられる。特
公昭54−24685号公報ではAs,Bi,Sn,S
b等の粒界偏析元素を鋼中に含有することにより、スラ
ブ加熱温度を1050〜1350℃の範囲にする方法が
開示され、特開昭52−24116号公報ではAlの
他、Zr,Ti,B,Nb,Ta,V,Cr,Mo等の
窒化物生成元素を含有することによりスラブ加熱温度を
1100〜1260℃の範囲にする方法を開示してい
る。また、特開昭57−158322号公報ではMn含
有量を下げ、Mn/Sの比率を2.5以下にすることに
より低温スラブ加熱化を行い、更にCuの添加により二
次再結晶を安定化する技術を開示している。As such inhibitors, sulfides, nitrides, oxides, grain boundary precipitation elements, and the like are considered, and known techniques include, for example, the following. In Japanese Patent Publication No. 54-24685, As, Bi, Sn, S
A method of controlling the slab heating temperature in the range of 1050 to 1350 ° C. by including grain boundary segregating elements such as b in the steel is disclosed. JP-A-52-24116 discloses Al, Zr, Ti It discloses a method for controlling the slab heating temperature in the range of 1100 to 1260 ° C. by containing a nitride forming element such as B, Nb, Ta, V, Cr and Mo. Further, in JP-A-57-158322, low-temperature slab heating is performed by lowering the Mn content and setting the Mn / S ratio to 2.5 or less, and further adding Cu to stabilize secondary recrystallization. The technology to do is disclosed.
【0008】これらインヒビターの補強と組み合わせて
金属組織の側から改良を加えた技術も開示された。すな
わち特開昭57−89433号公報ではMnに加えS,
Se,Sb,Bi,Pb,Sn,B等の元素を加え、こ
れにスラブの柱状晶率と二次冷延圧下率を組み合わせる
ことにより1100〜1250℃の低温スラブ加熱化を
実現している。更に特開昭59−190324号公報で
はSあるいはSeに加え、Al及びBと窒素を主体とし
てインヒビターを構成し、これに冷延後の一次再結晶焼
鈍時にパルス焼鈍を施すことにより二次再結晶を安定化
する技術を公開している。Techniques have also been disclosed in which improvements are made from the metallographic side in combination with the reinforcement of these inhibitors. That is, in JP-A-57-89433, S, in addition to Mn,
Elements such as Se, Sb, Bi, Pb, Sn, and B are added, and the columnar crystal ratio of the slab and the secondary cold rolling reduction are combined to realize low-temperature slab heating at 1100 to 1250 ° C. Further, in JP-A-59-190324, in addition to S or Se, an inhibitor is mainly composed of Al and B and nitrogen, and a secondary recrystallization is performed by performing pulse annealing at the time of primary recrystallization annealing after cold rolling. The technology to stabilize is released.
【0009】このように方向性電磁鋼板製造における低
温スラブ加熱化実現のためには、これまでに多大な努力
が続けられてきている。更に、特開昭59−56522
号公報においてはMnを0.08〜0.45%、Sを
0.007%以下にすることにより低温スラブ加熱化を
可能にする技術が開示された。この方法により高温スラ
ブ加熱時のスラブ結晶粒粗大化に起因する製品の線状二
次再結晶不良発生の問題が解消された。As described above, in order to realize the low temperature slab heating in the production of grain-oriented electrical steel sheet, great efforts have been made so far. Furthermore, JP-A-59-56522
In Japanese Patent Laid-Open Publication No. 2008-242242, a technique is disclosed which enables low temperature slab heating by setting Mn to 0.08 to 0.45% and S to 0.007% or less. By this method, the problem of defective linear secondary recrystallization of the product due to coarsening of the slab crystal grains during heating of the high temperature slab was solved.
【0010】[0010]
【発明が解決しようとする課題】低温スラブ加熱による
方法は元来、製造コストの低減を目的としているもの
の、当然のことながら良好な磁気特性を安定して得る技
術でなければ、工業化できない。本発明者らは、低温ス
ラブ加熱の工業化のため、最終仕上焼鈍前の一次再結
晶の平均粒径制御と、熱延後、最終仕上焼鈍の二次再
結晶開始までの間に鋼板に窒化処理を施すことを柱とす
る技術を構築してきた。この窒化処理により形成される
窒化物は、二次再結晶開始時点では、主にAlNになっ
ている。高温で変化しにくいインヒビターとして、Al
Nを選択しているわけであり、その意味において、スラ
ブ中にAlが含有されることが必須条件となる。Although the method using low temperature slab heating is originally intended to reduce the manufacturing cost, it cannot be industrialized unless it is a technique that can stably obtain good magnetic characteristics. The present inventors, for industrialization of low-temperature slab heating, control the average grain size of primary recrystallization before final finishing annealing, and after hot rolling, nitriding the steel sheet between the start of secondary recrystallization of final finishing annealing. We have built a technology that is based on The nitride formed by this nitriding treatment is mainly AlN at the start of secondary recrystallization. As an inhibitor that does not easily change at high temperatures, Al
Since N is selected, it is essential that Al is contained in the slab in that sense.
【0011】他方、スラブ中にNが必要以上に含有され
ることは、本技術体系からして、再考の余地があった。
つまり、スラブ中に必須のAlと、ある程度以上のN量
があれば、スラブ加熱から脱炭焼鈍までの工程で、Al
Nが形成され、脱炭焼鈍時の一次再結晶粒の粒成長に影
響を与えることとなる。本発明の目的は、この上工程で
のAlNの析出制御方策を検討し、低温スラブ加熱で、
かつ、熱延板焼鈍を省略してもなお磁性変動のない優れ
た特性を有する一方向性電磁鋼板の製造方法を提供する
ことにある。On the other hand, it is necessary to reconsider that N is contained in the slab more than necessary from the viewpoint of the present technical system.
In other words, if there is an indispensable Al in the slab and a certain amount of N or more, in the process from slab heating to decarburization annealing, Al
N is formed, which affects the grain growth of primary recrystallized grains during decarburization annealing. The purpose of the present invention is to study the AlN precipitation control strategy in the above process,
Another object of the present invention is to provide a method for producing a grain-oriented electrical steel sheet having excellent properties without magnetic fluctuation even if hot-rolled sheet annealing is omitted.
【0012】[0012]
【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、下記の通りである。 (1)重量比で、C:0.075%以下、Si:2.2
〜4.5%、酸可溶性Al:0.010〜0.060%、
N:0.0130%以下、S+0.405Se:0.0
14%以下、Mn:0.05〜0.8%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1280℃
未満の温度で加熱し、熱延を行い、引き続き熱延板焼鈍
を施すことなく、圧下率80%以上の最終強圧下冷延を
行い、次いで、脱炭焼鈍、最終仕上焼鈍を施して一方向
性電磁鋼板を製造する方法において、熱延板でのAlN
としてのN量(重量比)をN as AlNとした時、N*
=N−N as AlNの分析値を基に、その熱延以後に行
われる熱延の条件を決定し、脱炭焼鈍完了後、最終仕上
焼鈍開始までの一次再結晶粒の平均値を18〜35μm
とし、熱延後最終仕上焼鈍の二次再結晶開始までの間に
鋼板に0.0010重量%以上の窒素吸収を行わせる窒
化処理を施すことを特徴とする磁気特性の優れた一方向
性電磁鋼板の製造方法。 (2)前項において、スラブの成分として更にSn:
0.01〜0.15%を含有せしめることを特徴とする
磁気特性の優れた一方向性電磁鋼板の製造方法。The gist of the present invention is as follows. (1) C: 0.075% or less, Si: 2.2 by weight ratio
~ 4.5%, acid soluble Al: 0.010 to 0.060%,
N: 0.0130% or less, S + 0.405Se: 0.0
A slab containing 14% or less, Mn: 0.05 to 0.8%, and the balance Fe and unavoidable impurities at 1280 ° C.
Heating at a temperature of less than 1 hour, hot rolling, followed by final hot rolling with a reduction of 80% or more without hot-rolled sheet annealing, followed by decarburization annealing and final finishing annealing in one direction In a method for producing a heat-resistant electrical steel sheet, the method comprising:
When the N content (weight ratio) is N as AlN, N *
= N-N as AlN is used to determine the conditions of hot rolling performed after the hot rolling, and the average value of primary recrystallized grains after the completion of decarburizing annealing is 18 to 35 μm
The unidirectional electromagnetic wave having excellent magnetic properties, characterized in that the steel sheet is subjected to a nitriding treatment for absorbing 0.0010% by weight or more of nitrogen before the secondary recrystallization of the final finish annealing after hot rolling. Steel plate manufacturing method. (2) In the above paragraph, Sn:
A method for producing a grain-oriented electrical steel sheet having excellent magnetic properties, characterized by containing 0.01 to 0.15%.
【0013】[0013]
【作用】本発明が対象としている一方向性電磁鋼板は、
従来用いられている製鋼法で得られた溶鋼を連続鋳造法
あるいは造塊法で鋳造し、必要に応じて分塊工程をはさ
んでスラブとし、引き続き熱間圧延して熱延板とし、熱
延板を焼鈍することなく、次いで圧下率が80%以上と
なる最終冷延を施し、次いで、脱炭焼鈍、最終仕上焼鈍
を順次行うことによって製造される。The unidirectional electrical steel sheet targeted by the present invention is
Molten steel obtained by the conventional steelmaking method is cast by a continuous casting method or an ingot making method, and if necessary, the slab is separated by a slab, and then hot-rolled into a hot-rolled sheet. Without being annealed, the rolled sheet is subjected to final cold rolling with a reduction rate of 80% or more, followed by decarburization annealing and final finishing annealing in this order.
【0014】本発明者らは、熱延板焼鈍を省略した1回
冷延法で低温スラブ加熱材を製造する場合の磁性の変動
の原因とその解決策について詳細に検討した。そして、
その結果、熱延板でのAlNとしてのN量(N as Al
N)の分析値を基に、その熱延以降の熱延条件を制御す
ることによって、その磁性変動を激減できることをつき
とめた。The present inventors have examined in detail the cause of magnetic fluctuation and its solution in the case of producing a low temperature slab heating material by the single cold rolling method without hot-rolled sheet annealing. And
As a result, the amount of N as AlN in the hot rolled sheet (N as Al
Based on the analysis value of N), it was found that the magnetic fluctuation can be drastically reduced by controlling the hot rolling conditions after the hot rolling.
【0015】先ず、実験結果を基に、本発明の効果を説
明する。図1に、熱延板でのN−N as AlN量と製品
の磁束密度の関係を示す。この場合、重量比で、(A)
C:0.029%、Si:2.8%、酸可溶性Al:0.
035%、N:0.0050%、Mn:0.13%、
S:0.007%、(B)C:0.035%、Si:
3.10%、酸可溶性Al:0.037%、N:0.0
075%、Mn:0.14%、S:0.006%なる成
分を含有し、残部Fe及び不可避的不純物からなる25
0mm厚の2種類の成分のスラブを作成した。そして、1
050〜1250℃の温度に約90分保持した後、7パ
スで粗圧延を行い、40mm厚とし、次いで6パスで仕上
熱延を行い、2.3mm厚とした。この時、粗圧延時に水
冷を行ったり、粗熱延と仕上熱延間の時間を意図的に変
更したり、熱延終了から水冷開始までの時間を種々変更
した。First, the effect of the present invention will be described based on experimental results. FIG. 1 shows the relationship between the amount of N—N as AlN in the hot rolled sheet and the magnetic flux density of the product. In this case, the weight ratio is (A)
C: 0.029%, Si: 2.8%, acid-soluble Al: 0.
035%, N: 0.0050%, Mn: 0.13%,
S: 0.007%, (B) C: 0.035%, Si:
3.10%, acid soluble Al: 0.037%, N: 0.0
25% containing 075%, Mn: 0.14%, S: 0.006%, and the balance Fe and inevitable impurities.
A 0 mm thick slab of two components was made. And 1
After holding at a temperature of 050 to 1250 ° C. for about 90 minutes, rough rolling was performed in 7 passes to a thickness of 40 mm, and finish hot rolling was performed in 6 passes to a thickness of 2.3 mm. At this time, water cooling was performed during rough rolling, the time between rough hot rolling and finish hot rolling was intentionally changed, and the time from the end of hot rolling to the start of water cooling was variously changed.
【0016】かかる熱延板に熱延板焼鈍を施すことなく
約85%の強圧下圧延を行って最終板厚0.335mmの
冷延板とし、N2 :25%、H2 :75%、D.P.=
62℃雰囲気中で830℃に150秒保持する脱炭焼鈍
を施し、次いで、750℃に30秒保持する焼鈍時、焼
鈍雰囲気中にNH3 ガスを混入させ、鋼板に窒素吸収を
生ぜせしめた。Without hot-rolling sheet annealing, the hot-rolled sheet was subjected to strong reduction rolling of about 85% to obtain a cold-rolled sheet having a final thickness of 0.335 mm, N 2 : 25%, H 2 : 75%, D. P. =
Decarburization annealing was performed at 830 ° C. for 150 seconds in a 62 ° C. atmosphere, and then NH 3 gas was mixed into the annealing atmosphere during annealing at 750 ° C. for 30 seconds to cause nitrogen absorption in the steel sheet.
【0017】この窒化処理後のN量は、0.0181〜
0.0247重量%であり、一次再結晶粒の平均粒径
(円相当直径の平均値)は、20〜27μmであった。
かかる窒化処理後の鋼板にMgOを主成分とする焼鈍分
離剤を塗布し、最終仕上焼鈍を施した。また、本実験に
おける熱延板において、AlNとして存在するNの量
(=N as AlN)(重量比)を化学分析で求め、N−
N as AlNを計算して、製品の磁束密度との関係を求
めた。The amount of N after this nitriding treatment is 0.0181-
It was 0.0247% by weight, and the average particle size of primary recrystallized grains (average value of equivalent circle diameter) was 20 to 27 μm.
An annealing separator having MgO as a main component was applied to the steel sheet after the nitriding treatment, and final finish annealing was performed. In the hot rolled sheet in this experiment, the amount of N existing as AlN (= N as AlN) (weight ratio) was determined by chemical analysis, and N-
N as AlN was calculated to find the relationship with the magnetic flux density of the product.
【0018】図1から明らかなように、熱延板のN−N
as AlN量と製品の磁束密度とは相関関係があり、N
−N as AlNの最適値は、成分によって異っていた。
図1に示した熱延板でのAlN析出量を制御する効果の
メカニズムについて、必ずしも明らかではないが、本発
明者らは、以下のように推定している。As is clear from FIG. 1, the hot rolled sheet N--N
There is a correlation between the amount of as AlN and the magnetic flux density of the product.
The optimum value of -N as AlN varied depending on the components.
The mechanism of the effect of controlling the AlN precipitation amount in the hot rolled sheet shown in FIG. 1 is not necessarily clear, but the present inventors presume as follows.
【0019】本発明は、本発明者らが特開平2−182
866号公報で開示した脱炭焼鈍後の結晶組織を適切な
ものにすることを基本とする技術体系に属する。一方、
本発明の如き低温スラブ加熱の場合、スラブ加熱時のA
lNの完全溶体化は保障されていない。なお、脱炭焼鈍
時のAlNの析出状態は、一次再結晶粒の粒成長挙動に
影響を与える。特開平2−182866号公報で開示さ
れた如く、脱炭焼鈍後の結晶組織を制御すれば、良好な
磁気特性が得られるわけであるが、そのために、脱炭焼
鈍温度を極端に低くしたり、高くしたり、あるいは脱炭
焼鈍時間を極端に短くしたり、長くしたりすると、脱炭
が不十分となったり、FeO,SiO2等の表面層の酸
化物の状態が不適切となり製品被膜不良の原因となる。The present invention was made by the inventors of the present invention as disclosed in JP-A-2-182.
It belongs to a technical system disclosed in Japanese Patent No. 866, which is basically based on making the crystal structure after decarburization annealing appropriate. on the other hand,
In the case of low temperature slab heating as in the present invention, A during slab heating
Complete solution of 1N is not guaranteed. The AlN precipitation state during decarburization annealing affects the grain growth behavior of the primary recrystallized grains. As disclosed in JP-A-2-182866, if the crystal structure after decarburization annealing is controlled, good magnetic properties can be obtained. Therefore, the decarburization annealing temperature can be extremely lowered. If the temperature is increased, or the decarburization annealing time is extremely shortened or lengthened, decarburization becomes insufficient, or the oxide state of the surface layer such as FeO or SiO 2 becomes inadequate and the product coating It causes a defect.
【0020】従って、脱炭焼鈍の温度、時間にはおのず
と制御を受けるため、脱炭焼鈍時のAlNの析出状態に
は、望ましい範囲というものが存在することとなる。図
1に示した実験の脱炭焼鈍条件(焼鈍雰囲気、露点、温
度、時間)は、脱炭性、製品被膜の点で、良好な条件範
囲になっている。この条件において、熱延板のAlNの
析出量において適切な範囲があるということを示してお
り、このことは、脱炭焼鈍時のAlNの適切な析出状態
を熱延板のN−N as AlNの量で間接的にチェックで
きることを示している。Therefore, since the temperature and time of decarburization annealing are naturally controlled, there is a desirable range for the precipitation state of AlN during decarburization annealing. The decarburization annealing conditions (annealing atmosphere, dew point, temperature, time) of the experiment shown in FIG. 1 are in a good condition range in terms of decarburizing property and product coating. Under this condition, it is shown that there is an appropriate range in the precipitation amount of AlN of the hot-rolled sheet, which means that the appropriate precipitation state of AlN during decarburization annealing can be changed to N-N as AlN of the hot-rolled sheet. It indicates that the amount can be indirectly checked.
【0021】析出物による粒成長抑制効果(Zener
因子)は、析出物のサイズに逆比例しその体積分率に比
例する。熱延板ではNは窒化物としてほぼ100%析出
しているので、N−N as AlNの量は主に熱延後の巻
取り後に析出するSi3 N4,Fe16N4 等の析出量を
示しているものと解される。これらの不安定窒化物は、
脱炭焼鈍時分解し、AlNとして再析出すると考えられ
る。このAlNは、冷延によって増加した転位を析出核
とし、脱炭焼鈍の昇温中に、微細析出する傾向があるた
め、熱延板でのN−N as AlNの量は、脱炭焼鈍時の
微細AlN量を間接的に表わしていると解される。Grain Growth Suppression Effect (Zener)
Factor) is inversely proportional to the size of the precipitate and proportional to its volume fraction. Almost 100% of N is precipitated as a nitride in the hot-rolled sheet, so the amount of N-N as AlN is mainly the amount of precipitation of Si 3 N 4 , Fe 16 N 4, etc. that is precipitated after winding after hot rolling. Is understood to indicate. These unstable nitrides are
It is considered that it decomposes during decarburization annealing and reprecipitates as AlN. This AlN has dislocations increased by cold rolling as precipitation nuclei, and tends to be finely precipitated during the temperature rise during decarburization annealing. Therefore, the amount of N—N as AlN in the hot rolled sheet is It is understood that it indirectly represents the amount of fine AlN.
【0022】この微細AlN量が多すぎると、脱炭焼鈍
時の粒成長が過度に抑制されて、最適な脱炭焼鈍温度が
高くなりすぎ、脱炭焼鈍炉の加熱能力を超えることさえ
あり得る。またはこの微細AlN量が少なすぎると、脱
炭焼鈍時の粒成長が容易となりすぎて、最適な脱炭焼鈍
温度が低くなりすぎ、脱炭不良や表面酸化層形成不良の
原因となり得る。このように、熱延板でのN−N as A
lN量は、中間製品で材質を予測制御する上で重要なパ
ラメーターとなり得ると推定される。If the amount of this fine AlN is too large, grain growth during decarburization annealing is excessively suppressed, and the optimum decarburization annealing temperature becomes too high, which may even exceed the heating capacity of the decarburization annealing furnace. . Alternatively, if the amount of the fine AlN is too small, grain growth during decarburization annealing becomes too easy, and the optimum decarburization annealing temperature becomes too low, which may cause decarburization failure or surface oxide layer formation failure. Thus, N-N as A in hot rolled sheet
It is estimated that the 1N amount can be an important parameter in predicting and controlling the material quality of an intermediate product.
【0023】次に本発明の構成要件の限定理由について
述べる。先ず、スラブの成分と、スラブ加熱温度に関し
て限定理由を詳細に説明する。Cは、多くなりすぎると
脱炭焼鈍時間が長くなり経済的でないので0.075重
量%(以下単に%と略述)以下とした。なお磁気特性の
面で特に好ましい範囲は、0.020〜0.070%で
ある。Siは4.5%を超えると冷延時の割れが著しく
なるので4.5%以下とした。また、2.2%未満では
素材の固有抵抗が低すぎ、トランス鉄心材料として必要
な低鉄損が得られないので2.2%以上とした。Next, the reasons for limiting the constituent features of the present invention will be described. First, the reasons for limiting the components of the slab and the slab heating temperature will be described in detail. If C is too large, the decarburization annealing time becomes long and it is not economical, so it was made 0.075% by weight (hereinafter simply referred to as%) or less. In terms of magnetic properties, a particularly preferable range is 0.020 to 0.070%. When Si exceeds 4.5%, cracking during cold rolling becomes significant, so the content of Si is set to 4.5% or less. On the other hand, if it is less than 2.2%, the specific resistance of the material is too low, and the low iron loss required for the transformer core material cannot be obtained.
【0024】Alは二次再結晶の安定化に必要なAlN
もしくは(Al,Si)Nを確保するため、酸可溶性A
lとして0.010%以上が必要である。酸可溶性Al
が0.060%を超えると熱延板のAlNが不適切とな
り二次再結晶が不安定になるので0.060%以下とし
た。Nについては、0.0130%を超えるとブリスタ
ーと呼ばれる鋼板表面のふくれが発生するので0.01
30%以下とした。MnS,MnSeが鋼中に存在して
も、製造工程の条件を適正に選ぶことによって磁気特性
を良好にすることが可能である。しかしながらSやSe
が高いと線状細粒と呼ばれる二次再結晶不良部が発生す
る傾向があり、この二次再結晶不良部の発生を予防する
ためには(S+0.405Se)≦0.014%とすべ
きである。Al is AlN necessary for stabilizing the secondary recrystallization.
Alternatively, in order to secure (Al, Si) N, acid-soluble A
0.01% or more is required as l. Acid soluble Al
Is more than 0.060%, the AlN of the hot-rolled sheet becomes unsuitable and the secondary recrystallization becomes unstable, so the content was made 0.060% or less. Regarding N, if it exceeds 0.0130%, blisters on the surface of the steel sheet called blister occur, so 0.01
It was set to 30% or less. Even if MnS and MnSe are present in the steel, it is possible to improve the magnetic properties by properly selecting the conditions of the manufacturing process. However, S and Se
If the value is high, secondary recrystallization defects called linear fine grains tend to occur. To prevent the generation of secondary recrystallization defects, (S + 0.405Se) ≦ 0.014% should be satisfied. Is.
【0025】SあるいはSeが上記値を超える場合に
は、製造条件をいかに変更しても二次再結晶不良部が発
生する確率が高くなり好ましくない。また最終仕上焼鈍
で純化するのに要する時間が長くなりすぎて好ましくな
く、このような観点からSあるいはSeを不必要に増す
ことは意味がない。Mnの下限値は0.05%である。
0.05%未満では、熱間圧延によって得られる熱延板
の形状(平坦さ)、つまりストリップの側縁部が波形状
となり製品歩留りを低下させる問題が発生する。一方、
Mn量が0.8%を超えると製品の磁束密度を低下さ
せ、好ましくないので、Mn量の上限を0.8%とし
た。If S or Se exceeds the above value, the probability of occurrence of secondary recrystallization defects becomes high regardless of how the manufacturing conditions are changed, which is not preferable. In addition, the time required for purification in the final finish annealing is too long, which is not preferable, and it is meaningless to increase S or Se unnecessarily from this viewpoint. The lower limit of Mn is 0.05%.
If it is less than 0.05%, the shape (flatness) of the hot-rolled sheet obtained by hot rolling, that is, the side edge portion of the strip becomes wavy, which causes a problem of lowering the product yield. on the other hand,
If the Mn content exceeds 0.8%, the magnetic flux density of the product is lowered, which is not preferable, so the upper limit of the Mn content was set to 0.8%.
【0026】Snは、粒界偏析元素として知られてお
り、粒成長を抑制する元素である。一方スラブ加熱時S
nは完全固溶しており、通常考えられる数10℃の温度
差を有する加熱時のスラブ内でも、一様に固溶している
と考えられる。従って、温度差があるにも拘らず加熱時
のスラブ内で均一に分布しているSnは、脱炭焼鈍時の
粒成長抑制効果についても、場所的に均一に作用すると
考えられる。このため、AlNの場所的不均一に起因す
る脱炭焼鈍時の粒成長の場所的不均一を、Snは希釈す
る効果があるものと考えられる。従って、Snを添加す
ることは更に製品の磁気特性の変動を低減させるのに有
効である。Sn is known as a grain boundary segregation element and is an element that suppresses grain growth. On the other hand, when heating the slab S
It is considered that n is completely in solid solution, and is uniformly dissolved even in the slab at the time of heating having a temperature difference of several tens of degrees C which is usually considered. Therefore, it is considered that Sn, which is uniformly distributed in the slab during heating despite the temperature difference, also acts locally in terms of the grain growth suppressing effect during decarburization annealing. Therefore, it is considered that Sn has the effect of diluting the nonuniformity of grain growth during decarburization annealing due to the nonuniformity of AlN. Therefore, the addition of Sn is effective in further reducing the fluctuation of the magnetic properties of the product.
【0027】このSnの適正範囲を0.01〜0.15
%とした。この下限値未満では、粒成長抑制効果が少な
すぎて好ましくない。一方、この上限値を超えると鋼板
の窒化が難しくなり、二次再結晶不良の原因となるため
好ましくない。この他インヒビター構成元素として知ら
れているSb,Cu,Cr,Ni,B,Ti,Nb等を
微量に含有することはさしつかえない。特に、B,T
i,Nb等窒化物構成元素は、スラブ加熱時の鋼中の固
溶N量を低減するために積極的に添加してもかまわな
い。これらのAlよりNとの親和力の高い元素がある場
合には、後述する熱延板でのN−N as AlNの量を計
算する際に、全N量から含有するB,Ti,Nbのため
に形成される窒化物のN量を差し引きすることは、本発
明における制御効果の精度を高める上で好ましい。The proper range of Sn is 0.01 to 0.15.
%. Below this lower limit, the grain growth suppressing effect is too small, which is not preferable. On the other hand, if the upper limit is exceeded, nitriding of the steel sheet becomes difficult, which causes secondary recrystallization failure, which is not preferable. In addition to this, it may be contained a small amount of Sb, Cu, Cr, Ni, B, Ti, Nb, etc. which are known as inhibitor constituent elements. Especially B, T
Nitride constituent elements such as i and Nb may be positively added in order to reduce the amount of solid solution N in the steel during slab heating. When there are elements having a higher affinity for N than Al, B, Ti, and Nb contained from the total N amount when calculating the amount of N—N as AlN in the hot rolled sheet described later It is preferable to subtract the N amount of the nitride formed in order to improve the accuracy of the control effect in the present invention.
【0028】スラブ加熱温度は、普通鋼並にしてコスト
ダウンを行うという目的から1280℃未満と限定し
た。好ましくは1200℃以下である。加熱されたスラ
ブは、引き続き熱延されて熱延板となる。熱延工程は、
通常100〜400mm厚のスラブを加熱した後、いずれ
も複数回のパスで行う粗熱延と仕上熱延よりなる。粗熱
延の方法については特に限定するものではないが、Al
Nの析出量を制御するため、積極的に水冷を行う方策を
とってもよいし、パス間の時間を長くする方策をとって
もよい。逆に析出量を過度に増やさないようにするため
に、スラブ加熱温度を高めにしたり、パス間で保温カバ
ーを鋼板にかぶせたりする方策をとることも許される。The slab heating temperature is limited to less than 1280 ° C. for the purpose of cost reduction in the same manner as ordinary steel. It is preferably 1200 ° C or lower. The heated slab is subsequently hot rolled to form a hot rolled plate. The hot rolling process is
Usually, after heating a slab having a thickness of 100 to 400 mm, both are rough hot rolling and finish hot rolling which are carried out by a plurality of passes. The method of rough hot rolling is not particularly limited, but Al
In order to control the precipitation amount of N, it is possible to take measures to actively perform water cooling, or to take a measure to lengthen the time between passes. On the contrary, in order to prevent the precipitation amount from being excessively increased, it is possible to take measures such as increasing the slab heating temperature or covering the steel sheet with a heat insulating cover between passes.
【0029】粗熱延後仕上熱延までの時間については、
特に限定するものではないが、AlNの析出を促進させ
た方がよい場合は、パス間時間を延す等の方策をとるこ
とが許されるし、逆に、AlN析出を抑制する必要があ
る場合には、保熱カバーを鋼板にかぶせ、温度低下を少
なくする等の方策が許される。引き続く仕上熱延は、通
常4〜10パスの高速連続圧延で行われる。通常仕上熱
延の圧下配分は前段が圧下率が高く後段に行くほど圧下
率を下げて形状を良好なものとしている。Regarding the time from rough hot rolling to finish hot rolling,
Although not particularly limited, if it is better to promote the precipitation of AlN, it is possible to take measures such as extending the time between passes, and conversely, if it is necessary to suppress the precipitation of AlN. For this, measures such as covering the steel plate with a heat retaining cover to reduce the temperature decrease are allowed. Subsequent hot rolling for finishing is usually performed by high-speed continuous rolling for 4 to 10 passes. In the rolling distribution of normal hot rolling, the rolling ratio is high in the front stage and lower in the rear stage, and the shape is improved by lowering the rolling ratio.
【0030】圧延速度は通常100〜3000m/minと
なっており、パス間の時間は0.01〜100秒となっ
ている。本発明では仕上熱延条件を限定しているもので
はないが、熱延板でのAlN析出量を確保するために、
パス間で積極的に水冷して、AlNの析出温度域(80
0〜1000℃)で仕上熱延を施したり、逆にAlN析
出量が過度になるのを防ぐために、圧延速度をアップし
て、仕上熱延の終了温度を高めにすることも許される。The rolling speed is usually 100 to 3000 m / min, and the time between passes is 0.01 to 100 seconds. In the present invention, the finishing hot rolling conditions are not limited, but in order to secure the AlN precipitation amount in the hot rolled sheet,
Water is actively cooled between the passes, and the precipitation temperature range of AlN (80
It is also permitted to perform hot rolling for finishing at 0 to 1000 ° C., or conversely, to increase the rolling speed and raise the end temperature of finishing hot rolling in order to prevent excessive precipitation of AlN.
【0031】熱延の最終パス後、鋼板は通常0.1〜1
00秒程度空冷された後水冷され、300〜700℃の
温度で巻取られ、徐冷される。この冷却プロセスについ
ては特に限定されるものではないが、熱延後1秒以上空
冷等を行い、鋼板をAlN析出温度域にできるだけ長時
間保持する等の方法をAlN析出量制御に利用すること
は許される。After the final pass of hot rolling, the steel sheet is usually 0.1-1.
After being air-cooled for about 00 seconds, it is water-cooled, wound at a temperature of 300 to 700 ° C., and gradually cooled. The cooling process is not particularly limited, but a method of performing air cooling or the like for 1 second or more after hot rolling and keeping the steel sheet in the AlN precipitation temperature range as long as possible is not used for controlling the AlN precipitation amount. forgiven.
【0032】熱延板でのN* =N−N as AlNの分析
値を基に、その熱延以後に行われる熱延の条件を決定す
ると規定した。これは図1に示した如くN* と磁気特性
の相関が強いからである。また、工場で熱延を行う場
合、スラブ加熱炉の温度、粗熱延、仕上熱延時の冷却
等、ある程度の変動要因を内在している。従って、熱延
板でN* =N−N as AlNの分析値を測定し、この値
が適正値より大きい場合は、AlNが析出し易いように
以後の熱延条件を変更すればよく、逆にN* が適正値よ
り小さい場合には、AlNが析出しにくいように以後の
熱延条件を変更すればよい。It was stipulated that the conditions of hot rolling performed after the hot rolling should be determined based on the analysis value of N * = NN-AlN in the hot rolled sheet. This is because there is a strong correlation between N * and magnetic characteristics as shown in FIG. Further, when hot rolling is performed in a factory, there are some fluctuation factors such as the temperature of the slab heating furnace, rough hot rolling, and cooling during finish hot rolling. Therefore, the analysis value of N * = N-N as AlN is measured with the hot rolled sheet, and if this value is larger than the appropriate value, the subsequent hot rolling conditions may be changed so that AlN is easily precipitated. If N * is smaller than the appropriate value, the subsequent hot rolling conditions may be changed so that AlN is hard to precipitate.
【0033】N* の適正値の決定方法は、特に限定する
ものではなく、先行実験の結果を基に決定する方法等を
とることができる。また、以後の熱延条件を制御する方
策については、特に限定するものではなく、スラブ加熱
温度、粗熱延条件、粗熱延と仕上熱延のパス間時間、仕
上熱延後の空冷時間、熱延での冷却条件等どれを変更し
てもよい。その変更内容と変更とAlN析出の関係につ
いては、本発明の熱延条件を説明した部分で述べた通り
である。The method of determining the appropriate value of N * is not particularly limited, and a method of determining based on the result of the preceding experiment can be used. Further, the measures to control the subsequent hot rolling conditions are not particularly limited, slab heating temperature, rough hot rolling conditions, time between passes of rough hot rolling and finish hot rolling, air cooling time after finish hot rolling, Any of the cooling conditions such as hot rolling may be changed. The details of the change and the relationship between the change and the precipitation of AlN are as described in the section for explaining the hot rolling conditions of the present invention.
【0034】この熱延板は次いで、熱延板焼鈍を施すこ
となく圧下率80%以上の最終冷延を行う。最終冷延の
圧下率を80%以上としたのは、圧下率を上記範囲とす
ることによって、脱炭板において尖鋭な{110}〈0
01〉方位粒と、これに蚕食され易い対応方位粒({1
11}〈112〉方位粒等)を適正量得ることができ、
磁束密度を高める上で好ましいためである。かかる冷延
後の鋼板は、通常の方法で脱炭焼鈍、焼鈍分離剤塗布、
最終仕上焼鈍を施されて最終製品となる。ここで脱炭焼
鈍完了後、最終仕上焼鈍開始までの間の一次再結晶粒の
平均粒径を18〜35μmに制御することは、必要であ
る。その理由はこの平均粒径の範囲で良好な磁束密度が
得られ易く、かつ粒径変動に対する磁束密度の変化が少
ないからである。This hot-rolled sheet is then subjected to final cold rolling with a rolling reduction of 80% or more without performing hot-rolled sheet annealing. The reduction ratio of the final cold rolling is set to 80% or more because the reduction ratio in the above range makes the sharp decarburized plate {110} <0.
01> oriented grains and the corresponding oriented grains ({1
11} <112> oriented grains, etc.)
This is because it is preferable for increasing the magnetic flux density. The steel sheet after such cold rolling is decarburized and annealed by an ordinary method, an annealing separator is applied,
The final product is annealed to obtain the final product. Here, it is necessary to control the average grain size of the primary recrystallized grains to 18 to 35 μm after the completion of decarburization annealing and before the start of final finish annealing. The reason is that it is easy to obtain a good magnetic flux density in the range of the average particle size, and the change of the magnetic flux density due to the particle size variation is small.
【0035】そして、熱延後最終仕上焼鈍の二次再結晶
開始までの間に鋼板に窒化処理を施すと規定したのは、
本発明の如き低温スラブ加熱を前提とするプロセスで
は、二次再結晶に必要なインヒビター強度が不足がちに
なるからである。窒化の方法としては特に限定するもの
ではなく、脱炭焼鈍後引き続き焼鈍雰囲気にNH3 ガス
を混入させ窒化する方法、プラズマを用いる方法、焼鈍
分離剤に窒化物を添加し、最終仕上焼鈍の昇温中に窒化
物が分離してできた窒素を鋼板に吸収させる方法、最終
仕上焼鈍の雰囲気のN2 分圧を高めとし、鋼板を窒化す
る方法等いずれの方法でもよい。窒化量については二次
再結晶を安定して発現させるために10ppm 以上は必要
である。Then, it is defined that the steel sheet is subjected to the nitriding treatment before the secondary recrystallization of the final finish annealing after the hot rolling.
This is because the inhibitor strength required for secondary recrystallization tends to be insufficient in the process that is premised on low temperature slab heating as in the present invention. The nitriding method is not particularly limited, and a method of mixing NH 3 gas in an annealing atmosphere after decarburization annealing to perform nitriding, a method of using plasma, adding a nitride to an annealing separator and adding a nitride to the final finishing annealing is performed. Any method such as a method of absorbing nitrogen formed by separation of nitrides in the temperature into the steel sheet, a method of increasing the N 2 partial pressure in the atmosphere of final annealing and nitriding the steel sheet may be used. The nitriding amount is required to be 10 ppm or more in order to stably develop the secondary recrystallization.
【0036】[0036]
実施例1 重量%で、Si:3.05%、C:0.030%、酸可
溶性Al:0.037%、N:0.0080%、Mn:
0.14%、S:0.006%を含有する250mm厚の
スラブを1150℃で1時間保持した後、7パスで40
mm厚まで粗熱延し、しかる後、6パスで仕上熱延を行
い、2.3mm厚の熱延板とした。この熱延板のN as A
lNを分析し、N−N as AlNを計算すると、0.0
034%であった。この場合、磁気特性が不良となるこ
とが予想されたので、同成分のスラブを次に熱延するに
際し、(A)粗熱延中に、強制水冷を行い、仕上熱延開
始温度をスラブ加熱温度より、70〜80℃降下させる
熱延を行った。また、比較のため、(B)先の熱延と同
一条件での熱延も行った。(A)の熱延条件の場合も、
熱延板のN as AlNを分析し、N−N as AlNを計
算すると、0.0025%であった。Example 1 By weight%, Si: 3.05%, C: 0.030%, acid-soluble Al: 0.037%, N: 0.0080%, Mn:
A 250 mm-thick slab containing 0.14% and S: 0.006% was held at 1150 ° C for 1 hour, and then 40 times in 7 passes.
After roughly hot rolling to a thickness of mm, finishing hot rolling was performed in 6 passes to obtain a hot rolled sheet having a thickness of 2.3 mm. N as A of this hot rolled sheet
ln was analyzed and N-N as AlN was calculated to be 0.0
It was 034%. In this case, it was expected that the magnetic properties would be poor. Therefore, when hot rolling the slab of the same component next time, (A) during rough hot rolling, forced water cooling was performed to set the finish hot rolling start temperature to the slab heating temperature. Hot rolling was performed by lowering the temperature by 70 to 80 ° C. For comparison, hot rolling under the same conditions as the hot rolling of (B) was also performed. In the case of the hot rolling condition of (A),
The N as AlN of the hot-rolled sheet was analyzed, and the N-N as AlN was calculated to be 0.0025%.
【0037】この2種類の熱延板を酸洗し、約85%の
圧下率で冷延して、0.335mm厚の冷延板とした。し
かる後、835℃に150秒保持する脱炭焼鈍(25%
N2+75%H2 ,露点60℃)を施し、しかる後、7
50℃で30秒保持する焼鈍を行い、焼鈍雰囲気中にN
H3 ガスを混入させ鋼板に窒素を吸収せしめた。窒化後
の鋼板のN量は0.0215〜0.0232%であり、
鋼板の一次再結晶粒の平均粒径は、21〜24μmであ
った。次いで、この鋼板にMgOを主成分とする焼鈍分
離剤を塗布し、公知の方法で、最終仕上焼鈍を施した。
実験条件と磁気特性の結果を表1に示す。These two kinds of hot rolled sheets were pickled and cold rolled at a reduction rate of about 85% to obtain cold rolled sheets having a thickness of 0.335 mm. Then, decarburization annealing (25% at 150 ° C for 150 seconds)
N 2 + 75% H 2 , dew point 60 ° C.), and then 7
Annealing is carried out at 50 ° C for 30 seconds, and N
The steel plate was made to absorb nitrogen by mixing H 3 gas. The N content of the steel sheet after nitriding is 0.0215 to 0.0232%,
The average grain size of the primary recrystallized grains of the steel sheet was 21 to 24 μm. Then, an annealing separator having MgO as a main component was applied to this steel sheet, and final finish annealing was performed by a known method.
Table 1 shows the experimental conditions and the results of magnetic properties.
【0038】[0038]
【表1】 [Table 1]
【0039】実施例2 重量%で、Si:3.25%、C:0.045%、酸可
溶性Al:0.034%、N:0.0061%、Mn:
0.13%、S:0.005%を含有する250mm厚の
スラブを1150℃で、1時間保持した後、7パスで3
0mm厚まで粗熱延し、しかる後、6パスで仕上熱延を行
い、2.3mm厚の熱延板とした。この熱延板のN as A
lNを分析し、N−N as AlNを計算すると、0.0
032%であった。この場合、磁気特性が不良になるこ
とが予想されたので、同成分のスラブを次に熱延するに
際し、(A)スラブ加熱温度を1080℃にし、その他
の条件は先と同一で熱延を行った。また、比較のため、
(B)先の熱延と同一条件での熱延も行った。(A)の
熱延条件の場合も、熱延板のN as AlNを分析し、N
−N as AlNを計算すると、0.0024%であっ
た。Example 2 By weight%, Si: 3.25%, C: 0.045%, acid-soluble Al: 0.034%, N: 0.0061%, Mn:
A 250 mm-thick slab containing 0.13% and S: 0.005% was held at 1150 ° C. for 1 hour and then 3 passes in 7 passes.
Rough hot rolling was performed to a thickness of 0 mm, and then finish hot rolling was performed in 6 passes to obtain a hot rolled sheet having a thickness of 2.3 mm. N as A of this hot rolled sheet
ln was analyzed and N-N as AlN was calculated to be 0.0
It was 032%. In this case, it was expected that the magnetic properties would be poor, so (A) when heating the slab of the same component next, the slab heating temperature was set to 1080 ° C., and the other conditions were the same as before. went. Also, for comparison,
(B) Hot rolling was also performed under the same conditions as the above hot rolling. Also in the case of the hot rolling condition of (A), N as AlN of the hot rolled sheet is analyzed, and N
The calculated —N as AlN was 0.0024%.
【0040】この2種類の熱延板を酸洗し、約88%の
圧下率で冷延して、0.285mm厚の冷延板とした。し
かる後、840℃に150秒保持する脱炭焼鈍(25%
N2+75%H2 、露点60℃)を施し、しかる後、7
50℃で30秒保持する焼鈍を行い、焼鈍雰囲気中にN
H3 ガスを混入させ鋼板に窒素を吸収せしめた。窒化後
の鋼板のN量は0.0208〜0.0229%であり、
鋼板の一次再結晶粒の平均粒径は、21〜24μmであ
った。次いで、この鋼板にMgOを主成分とする焼鈍分
離剤を塗布し、公知の方法で、最終仕上焼鈍を施した。
実験条件と磁気特性の結果を表2に示す。The two types of hot rolled sheets were pickled and cold rolled at a rolling reduction of about 88% to obtain cold rolled sheets having a thickness of 0.285 mm. Then, decarburization annealing (at 25%
N 2 + 75% H 2 , dew point 60 ° C.), and then 7
Annealing is carried out at 50 ° C for 30 seconds, and N
The steel plate was made to absorb nitrogen by mixing H 3 gas. The N content of the steel sheet after nitriding is 0.0208 to 0.0229%,
The average grain size of the primary recrystallized grains of the steel sheet was 21 to 24 μm. Then, an annealing separator having MgO as a main component was applied to this steel sheet, and final finish annealing was performed by a known method.
Table 2 shows the experimental conditions and the results of magnetic properties.
【0041】[0041]
【表2】 [Table 2]
【0042】実施例3 重量%で、Si:2.86%、C:0.029%、酸可
溶性Al:0.032%、N:0.0050%、Mn:
0.13%、S:0.006%を含有し、更に、(1)
Sn<0.005%、(2)Sn:0.06%を含有す
る250mm厚の2種類のスラブを1180℃で、1時間
保持した後、7パスで40mm厚まで粗熱延し、しかる
後、6パスで仕上熱延を行い、2.8mm厚の熱延板とし
た。この熱延板のN as AlNを分析し、N−N as A
lNを計算すると、各々、(1)0.0028%、
(2)0.0030%であった。Example 3 By weight%, Si: 2.86%, C: 0.029%, acid-soluble Al: 0.032%, N: 0.0050%, Mn:
0.13%, S: 0.006%, and (1)
Two 250 mm-thick slabs containing Sn <0.005%, (2) Sn: 0.06% were held at 1180 ° C. for 1 hour, and then roughly hot-rolled to 40 mm-thickness in 7 passes. Finishing hot rolling was performed in 6 passes to obtain a hot rolled plate having a thickness of 2.8 mm. This hot rolled sheet was analyzed for N as AlN, and N-N as A
When 1N is calculated, (1) 0.0028%,
(2) It was 0.0030%.
【0043】この場合、磁気特性が不良となることが予
想されたので、同成分のスラブを次に熱延するに際し、
(A)粗熱延後に、60秒空冷を行い、仕上熱延開始温
度をスラブ加熱温度より、65〜75℃降下させる熱延
方法を行った。また、比較のため、(B)先の熱延と同
一条件での熱延も行った。(A)の熱延条件の場合も、
熱延板のN as AlNを分析し、N−N as AlNを計
算すると、各々、(1)0.0017%、(2)0.0
020%であった。In this case, since it was expected that the magnetic characteristics would be poor, when the slab of the same composition was hot-rolled next,
(A) After the rough hot rolling, air cooling was performed for 60 seconds, and a hot rolling method of lowering the finish hot rolling start temperature by 65 to 75 ° C. from the slab heating temperature was performed. For comparison, hot rolling under the same conditions as the hot rolling of (B) was also performed. In the case of the hot rolling condition of (A),
When N as AlN of the hot rolled sheet was analyzed and N-N as AlN was calculated, (1) 0.0017%, (2) 0.0
It was 020%.
【0044】この2種類の熱延板を酸洗し、約88%の
圧下率で冷延して、0.335mm厚の冷延板とした。し
かる後、840℃に150秒保持する脱炭焼鈍(25%
N2+75%H2 、露点60℃)を施し、しかる後、7
50℃で30秒保持する焼鈍を行い、焼鈍雰囲気中にN
H3 ガスを混入させ鋼板に窒素を吸収せしめた。窒化後
の鋼板のN量は0.0223〜0.0232%であり、
鋼板の一次再結晶粒の平均粒径は、22〜25μmであ
った。次いで、この鋼板にMgOを主成分とする焼鈍分
離剤を塗布し、公知の方法で、最終仕上焼鈍を施した。
実験条件と磁気特性の結果を表3に示す。These two kinds of hot rolled sheets were pickled and cold rolled at a rolling reduction of about 88% to obtain cold rolled sheets having a thickness of 0.335 mm. Then, decarburization annealing (at 25%
N 2 + 75% H 2 , dew point 60 ° C.), and then 7
Annealing is carried out at 50 ° C for 30 seconds, and N
The steel plate was made to absorb nitrogen by mixing H 3 gas. The N content of the steel sheet after nitriding is 0.0223 to 0.0232%,
The average grain size of the primary recrystallized grains of the steel sheet was 22 to 25 μm. Then, an annealing separator having MgO as a main component was applied to this steel sheet, and final finish annealing was performed by a known method.
Table 3 shows the experimental conditions and the results of magnetic properties.
【0045】[0045]
【表3】 [Table 3]
【0046】[0046]
【発明の効果】本発明においては、熱延板のAlN析出
量を基に熱延条件をフィードバック制御し、一次再結晶
粒の平均粒径を制御し、熱延後、最終仕上焼鈍の二次再
結晶開始までの間に鋼板に窒化処理を施し、更には、S
n添加を行うことにより、低温スラブ加熱で、かつ熱延
板焼鈍を省略してもなお、良好な磁気特性を安定して得
ることができるので、その工業的効果は大である。INDUSTRIAL APPLICABILITY In the present invention, the hot rolling conditions are feedback-controlled based on the AlN precipitation amount of the hot rolled sheet, the average grain size of the primary recrystallized grains is controlled, and after the hot rolling, the secondary finish annealing is performed. The steel sheet is nitrided before the start of recrystallization, and further, S
By adding n, it is possible to stably obtain good magnetic characteristics even if the low temperature slab heating is performed and the hot-rolled sheet annealing is omitted, so that the industrial effect is great.
【図1】熱延板でのN−N as AlN量と製品の磁束密
度の関係を表わすグラフである。FIG. 1 is a graph showing the relationship between the amount of N—N as AlN in a hot rolled sheet and the magnetic flux density of a product.
Claims (2)
0℃未満の温度で加熱し、熱延を行い、引き続き熱延板
焼鈍を施すことなく、圧下率80%以上の最終強圧下冷
延を行い、次いで脱炭焼鈍、最終仕上焼鈍を施して一方
向性電磁鋼板を製造する方法において、熱延板でのAl
NとしてのN量(重量比)をN as AlNとした時、N
* =N−N as AlNの分析値を基に、その熱延以後に
行われる熱延の条件を決定し、脱炭焼鈍完了後、最終仕
上焼鈍開始までの一次再結晶粒の平均粒径を18〜35
μmとし、熱延後最終仕上焼鈍の二次再結晶開始までの
間に鋼板に0.0010重量%以上の窒素吸収を行わせ
る窒化処理を施すことを特徴とする磁気特性の優れた一
方向性電磁鋼板の製造方法。1. By weight ratio, C: 0.075% or less, Si: 2.2-4.5%, acid-soluble Al: 0.010-0.060%, N: 0.0130% or less, S + 0. 405 Se: 0.014% or less, Mn: 0.05 to 0.8%, 128 slabs with the balance being Fe and unavoidable impurities
It is heated at a temperature lower than 0 ° C, hot-rolled, and subsequently subjected to final strong cold-rolling with a rolling reduction of 80% or more without performing hot-rolled sheet annealing, followed by decarburization annealing and final finishing annealing. In a method for producing a grain-oriented electrical steel sheet, Al in a hot rolled sheet is used.
When the amount of N as N (weight ratio) is N as AlN, N
* = N-N as AlN Based on the analysis value, determine the conditions of hot rolling to be performed after the hot rolling, and determine the average grain size of the primary recrystallized grains after the completion of decarburizing annealing until the start of final finishing annealing. 18-35
unidirectionality with excellent magnetic properties, characterized in that the steel sheet is subjected to a nitriding treatment to absorb 0.0010% by weight or more of nitrogen before the secondary recrystallization of the final finish annealing after hot rolling. Manufacturing method of electrical steel sheet.
0.15%を含有せしめることを特徴とする請求項1記
載の磁気特性の優れた一方向性電磁鋼板の製造方法。2. As a slab component, Sn: 0.01-
0.15% is contained, The manufacturing method of the grain-oriented electrical steel sheet excellent in the magnetic characteristic of Claim 1 characterized by the above-mentioned.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28667093A JPH07138643A (en) | 1993-11-16 | 1993-11-16 | Production of grain-oriented electrical steel sheet excellent in magnetic property |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28667093A JPH07138643A (en) | 1993-11-16 | 1993-11-16 | Production of grain-oriented electrical steel sheet excellent in magnetic property |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH07138643A true JPH07138643A (en) | 1995-05-30 |
Family
ID=17707444
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP28667093A Withdrawn JPH07138643A (en) | 1993-11-16 | 1993-11-16 | Production of grain-oriented electrical steel sheet excellent in magnetic property |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH07138643A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100514790B1 (en) * | 2000-12-19 | 2005-09-14 | 주식회사 포스코 | A method for manufacturing grain-oriented electrical steel sheet with superior magnetic property using the low temperature heating method |
KR100797997B1 (en) * | 2006-12-27 | 2008-01-28 | 주식회사 포스코 | Method for manufacturing grain-oriented electrical steel sheets with excellent magnetic property and high productivity |
WO2008078915A1 (en) * | 2006-12-27 | 2008-07-03 | Posco | Method for manufacturing grain-oriented electrical steel sheets with excellent magnetic property and high productivity |
KR101408230B1 (en) * | 2007-08-22 | 2014-06-17 | 주식회사 포스코 | Method for manufacturing grain-oriented electrical steel sheets with excellent magnetic property and high productivity |
-
1993
- 1993-11-16 JP JP28667093A patent/JPH07138643A/en not_active Withdrawn
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100514790B1 (en) * | 2000-12-19 | 2005-09-14 | 주식회사 포스코 | A method for manufacturing grain-oriented electrical steel sheet with superior magnetic property using the low temperature heating method |
KR100797997B1 (en) * | 2006-12-27 | 2008-01-28 | 주식회사 포스코 | Method for manufacturing grain-oriented electrical steel sheets with excellent magnetic property and high productivity |
WO2008078915A1 (en) * | 2006-12-27 | 2008-07-03 | Posco | Method for manufacturing grain-oriented electrical steel sheets with excellent magnetic property and high productivity |
KR101408230B1 (en) * | 2007-08-22 | 2014-06-17 | 주식회사 포스코 | Method for manufacturing grain-oriented electrical steel sheets with excellent magnetic property and high productivity |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2876173B1 (en) | Manufacturing method of electrical steel sheet grain-oriented | |
JP4203238B2 (en) | Manufacturing method of unidirectional electrical steel sheet | |
JP2005226111A (en) | Method for producing grain-oriented silicon steel sheet excellent in magnetic characteristic | |
JPH0730397B2 (en) | Method for producing unidirectional electrical steel sheet with excellent magnetic properties | |
JP2607331B2 (en) | Manufacturing method of grain-oriented electrical steel sheet with excellent magnetic properties | |
JPH07138643A (en) | Production of grain-oriented electrical steel sheet excellent in magnetic property | |
JPH07118746A (en) | Stable production of grain-oriented silicon steel sheet excellent in magnetic property | |
JP2521585B2 (en) | Method for producing unidirectional electrical steel sheet with excellent magnetic properties | |
JP3169490B2 (en) | Manufacturing method of grain-oriented electrical steel sheet with excellent magnetic properties | |
JP3314844B2 (en) | Manufacturing method of unidirectional electrical steel sheet with excellent magnetic properties and coating properties | |
JP2948454B2 (en) | Method for stable production of unidirectional electrical steel sheets with excellent magnetic properties | |
KR102319831B1 (en) | Method of grain oriented electrical steel sheet | |
JP2948455B2 (en) | Method for stable production of unidirectional electrical steel sheets with excellent magnetic properties | |
JP2521586B2 (en) | Method for producing unidirectional electrical steel sheet with excellent magnetic properties | |
JP3348217B2 (en) | Method for stable production of unidirectional electrical steel sheets with excellent magnetic properties | |
JPH11269543A (en) | Production of grain oriented electric steel sheet | |
JP3474594B2 (en) | Manufacturing method of unidirectional electrical steel sheet with excellent thickness and thickness | |
JP2002129236A (en) | Method for stably manufacturing grain oriented silicon steel sheet | |
JPH06306474A (en) | Production of grain-oriented magnetic steel sheet excellent in magnetic property | |
JP3849310B2 (en) | Method for producing grain-oriented electrical steel sheet without ear cracks | |
JPH07310124A (en) | Production of thick grain-oriented silicon steel plate excellent in magnetic characteristic and film coating characteristic | |
JPH07138642A (en) | Production of grain-oriented electrical steel sheet excellent in magnetic property | |
JPH0788531B2 (en) | Method for producing unidirectional electrical steel sheet with excellent magnetic properties | |
JPH05156361A (en) | Manufacture of grain-oriented electric steel sheet excellent in magnetic property | |
JPH10183249A (en) | Production of grain oriented silicon steel sheet excellent in magnetic property |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20010130 |