JP4613611B2 - Method for producing non-oriented electrical steel sheet - Google Patents
Method for producing non-oriented electrical steel sheet Download PDFInfo
- Publication number
- JP4613611B2 JP4613611B2 JP2004377135A JP2004377135A JP4613611B2 JP 4613611 B2 JP4613611 B2 JP 4613611B2 JP 2004377135 A JP2004377135 A JP 2004377135A JP 2004377135 A JP2004377135 A JP 2004377135A JP 4613611 B2 JP4613611 B2 JP 4613611B2
- Authority
- JP
- Japan
- Prior art keywords
- hot
- annealing
- rolled
- less
- rolled sheet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Manufacturing Of Steel Electrode Plates (AREA)
- Soft Magnetic Materials (AREA)
Description
本発明は、モータやＥＩコアの鉄心材料等に使用して好適な無方向性電磁鋼板の有利な製造方法に関するものである。 The present invention relates to an advantageous method for producing a non-oriented electrical steel sheet suitable for use in a motor, an EI core iron core material, and the like.
近年、省エネルギーに対するニーズの高まりに伴い、モータの高効率化への要望も高まっている。モータの高効率化を達成するためには、コア材として使用される電磁鋼板の高性能化が不可欠であることから、これまで以上に磁束密度が高くかつ鉄損の低い電磁鋼板が強く求められている。 In recent years, with increasing needs for energy saving, there is an increasing demand for higher motor efficiency. In order to achieve high motor efficiency, it is essential to improve the performance of the electrical steel sheet used as the core material. Therefore, there is a strong demand for electrical steel sheets with higher magnetic flux density and lower iron loss than ever before. ing.
電磁鋼板の磁束密度を高めるためには、冷間圧延前の結晶粒を粗大化させることが効果的であることから、熱延鋼板にスキンパスを付与して焼鈍を行う技術（例えば特許文献１）や、熱間圧延後に高温巻取りを行い、鋼帯の保有する熱で自己焼鈍を行う技術（例えば特許文献２）が提案されている。
また、冷間圧延前に二次再結晶を生じさせて結晶粒を粗大にすることにより、磁気特性を向上させる技術（例えば特許文献３）も提案されている。
In order to increase the magnetic flux density of the electrical steel sheet, it is effective to coarsen the crystal grains before cold rolling, and therefore a technique for performing annealing by imparting a skin pass to the hot-rolled steel sheet (for example, Patent Document 1). Or the technique (for example, patent document 2) which performs high temperature winding after hot rolling and performs self-annealing with the heat which a steel strip holds is proposed.
In addition, a technique (for example, Patent Document 3) for improving magnetic properties by causing secondary recrystallization before cold rolling to make crystal grains coarse has been proposed.
しかしながら、近年では、前述したようなモータの高効率化に対する強い要望から、さらに磁束密度の高い材料が求められている。
本発明は、上記の実状に鑑み開発されたもので、従来に比し磁束密度が高くかつ鉄損が低い、磁気特性に優れた無方向性電磁鋼板の有利な製造方法を提供することを目的とする。
However, in recent years, materials with higher magnetic flux density have been demanded due to the strong demand for higher motor efficiency as described above.
The present invention was developed in view of the above-mentioned actual situation, and an object thereof is to provide an advantageous method for producing a non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss as compared with the prior art and excellent in magnetic properties. And
さて、発明者らは、上記の課題を解決すべく鋭意検討を重ねた結果、以下に述べる知見を得た。
従来、磁気特性の観点からは、鋼中のＣ量は少ない方が良いとされていたのであるが、発明者らの研究によれば、むしろ鋼中Ｃ量を多めにして、熱延板焼鈍段階においてフェライト中にセメンタイトが微細に分散した組織とすることが、磁気特性の改善には有利であることが判明した。
As a result of intensive studies to solve the above problems, the inventors have obtained the following knowledge.
Conventionally, from the viewpoint of magnetic properties, it was considered better to have a smaller amount of C in steel. However, according to the study by the inventors, rather, the amount of C in steel was increased and hot-rolled sheet annealing was performed. It has been found that it is advantageous to improve the magnetic properties to have a structure in which cementite is finely dispersed in ferrite in the stage.
すなわち、
(a) 鋼中のＣ量を0.01〜0.2質量％と高めた上で、鋼の熱延板焼鈍をＡc3点以上のオーステナイト域で行い、熱延板焼鈍段階においてフェライト中にセメンタイトが微細に分散した組織を形成することによって、磁束密度が向上する、
(b) さらに温間圧延や熱延板焼鈍後の所定温度域での冷却速度の制御と組み合わせると、磁束密度がより一層向上する
ことの知見を得たのである。
本発明は、上記の知見に立脚するものである。
That is,
(a) After increasing the amount of C in the steel to 0.01 to 0.2 mass%, the steel is subjected to hot-rolled sheet annealing in the austenite region of Ac 3 or more, and the cementite is finely contained in the ferrite in the hot-rolled sheet annealing stage. By forming a dispersed structure, the magnetic flux density is improved.
(b) Furthermore, when combined with control of the cooling rate in a predetermined temperature range after warm rolling or hot-rolled sheet annealing, it has been found that the magnetic flux density is further improved.
The present invention is based on the above findings.
すなわち、本発明の要旨構成は次のとおりである。
（１）質量％で、
Ｃ：0.01〜0.2％、
Si：３％以下、
Mn：0.05〜3.0％、
Al：１％以下、
Ｐ：0.2％以下、
Ｓ：0.01％以下および
Ｎ：0.005％以下
を含み、残部はFeおよび不可避不純物の組成になる鋼材を、熱間圧延し、熱延板焼鈍後、最終板厚まで圧延し、ついで脱炭焼鈍および仕上焼鈍を施す一連の工程によって無方向性電磁鋼板を製造するに際し、熱延板焼鈍をＡc3点以上の温度域で行い、該熱延板焼鈍後、少なくとも800〜500℃の温度域を平均冷却速度：１℃/s以上で冷却することを特徴とする磁気特性に優れた無方向性電磁鋼板の製造方法。
That is, the gist configuration of the present invention is as follows.
( 1 ) In mass%,
C: 0.01-0.2%
Si: 3% or less,
Mn: 0.05-3.0%
Al: 1% or less,
P: 0.2% or less,
S: 0.01% or less and N: 0.005% or less, with the balance being Fe and unavoidable impurities, hot rolled, hot-rolled sheet annealed, rolled to final thickness, then decarburized annealed and When producing a non-oriented electrical steel sheet by a series of processes for performing finish annealing, hot-rolled sheet annealing is performed in a temperature range of Ac 3 points or more, and after the hot-rolled sheet annealing, a temperature range of at least 800 to 500 ° C is averaged. A method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by cooling at a cooling rate of 1 ° C./s or more.
（２）質量％で、
Ｃ：0.01〜0.2％、
Si：３％以下、
Mn：0.05〜3.0％、
Al：１％以下、
Ｐ：0.2％以下、
Ｓ：0.01％以下および
Ｎ：0.005％以下
を含み、残部はFeおよび不可避不純物の組成になる鋼材を、熱間圧延し、熱延板焼鈍後、最終板厚まで圧延し、ついで脱炭焼鈍および仕上焼鈍を施す一連の工程によって無方向性電磁鋼板を製造するに際し、熱延板焼鈍をＡc3点以上の温度域で行い、該熱延板焼鈍後、少なくとも800〜500℃の温度域を平均冷却速度：１℃/s以上で冷却し、引き続き70〜400℃の温度域にて温間圧延を行うことを特徴とする磁気特性に優れた無方向性電磁鋼板の製造方法。
( 2 ) In mass%,
C: 0.01-0.2%
Si: 3% or less,
Mn: 0.05-3.0%
Al: 1% or less,
P: 0.2% or less,
S: 0.01% or less and N: 0.005% or less, with the balance being Fe and unavoidable impurities, hot rolled, hot-rolled sheet annealed, rolled to final thickness, then decarburized annealed and When producing a non-oriented electrical steel sheet by a series of processes for performing finish annealing, hot-rolled sheet annealing is performed in a temperature range of Ac 3 points or more, and after the hot-rolled sheet annealing, a temperature range of at least 800 to 500 ° C is averaged. A method for producing a non-oriented electrical steel sheet excellent in magnetic properties, characterized by cooling at a cooling rate of 1 ° C./s or more and subsequently performing warm rolling in a temperature range of 70 to 400 ° C.
本発明に従い、熱延板焼鈍段階においてフェライト中にセメンタイトが微細に分散した組織を形成することにより、磁束密度が高くかつ鉄損が低い無方向性電磁鋼板を得ることができる。
従って、本発明に従い得られた鋼板を使用することにより、例えば高効率誘導モータやＥＩコアの高効率化に大きく貢献する。
According to the present invention, a non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss can be obtained by forming a structure in which cementite is finely dispersed in ferrite in the hot-rolled sheet annealing stage.
Therefore, the use of the steel sheet obtained according to the present invention greatly contributes to, for example, high efficiency induction motors and EI cores.
以下、本発明を由来するに至った実験結果について説明する。なお、成分に関する「％」表示は特に断らない限り質量％を意味するものとする。
まず、磁束密度に及ぼす熱延板焼鈍条件の影響を調査するため、Ｃ：0.02％、Si：1.0％、Mn：0.05％、Al：tr、Ｐ：0.05％、Ｓ：0.0010％およびＮ：0.002％を含有し、残部はFeおよび不可避的不純物の組成になる鋼を、真空溶解し、熱延後、800〜1150℃，30ｓの熱延板焼鈍を行った。ついで、熱延板焼鈍後にミスト冷却し、その際、800〜500℃における平均冷却速度を測定したところ、60℃/sであった。その後、板厚：0.5mmまで冷間圧延した。引き続き、20vol%H2−80vol%N2、露点：＋35℃の雰囲気中にて850℃，60ｓの脱炭焼鈍を行い、さらに25vol%H2−75vol%N2雰囲気中にて950℃，10ｓの仕上焼鈍を行った。
Hereinafter, the experimental results that led to the present invention will be described. Unless otherwise specified, “%” in relation to ingredients means mass%.
First, in order to investigate the influence of hot-rolled sheet annealing conditions on magnetic flux density, C: 0.02%, Si: 1.0%, Mn: 0.05%, Al: tr, P: 0.05%, S: 0.0010% and N: 0.002 %, With the balance being Fe and an inevitable impurity composition, the steel was vacuum melted, hot-rolled, and then annealed at 800 to 1150 ° C. for 30 seconds. Next, mist cooling was performed after hot-rolled sheet annealing. At that time, the average cooling rate at 800 to 500 ° C. was measured and found to be 60 ° C./s. Thereafter, the sheet was cold-rolled to a thickness of 0.5 mm. Subsequently, decarburization annealing was performed at 850 ° C. for 60 s in an atmosphere of 20 vol% H 2 −80 vol% N 2 and dew point: + 35 ° C., and further 950 ° C. for 10 s in 25 vol% H 2 −75 vol% N 2 atmosphere. Finish annealing was performed.
図１に、熱延板焼鈍温度と磁束密度との関係について調べた結果を示す。
同図より、熱延板焼鈍温度が1040℃以上の場合に、磁束密度が大きく向上することが分かる。
In FIG. 1, the result of having investigated about the relationship between hot-rolled sheet annealing temperature and magnetic flux density is shown.
From the figure, it can be seen that the magnetic flux density is greatly improved when the hot-rolled sheet annealing temperature is 1040 ° C. or higher.
この原因を調査するため、熱延板焼鈍後における鋼板の組織観察を行った。
その結果、1040℃以上の温度で熱延板焼鈍を行った材料は、旧オーステナイト粒界が認められ、さらにフェライト中にセメンタイトが微細に分散した組織となっていた。この組織観察の結果より、1040℃以上の熱延板焼鈍段階では、組織はオーステナイトになっていたものと考えられる。
In order to investigate this cause, the structure of the steel sheet after hot-rolled sheet annealing was observed.
As a result, the material subjected to hot-rolled sheet annealing at a temperature of 1040 ° C. or higher had a prior austenite grain boundary and a structure in which cementite was finely dispersed in ferrite. From the results of this structure observation, it is considered that the structure was austenite in the hot rolled sheet annealing stage at 1040 ° C. or higher.
そこで、本材料のＡc3変態点を、フォーマスター試験機を用い、30℃/sの昇温中の熱膨張率を測定することにより調査した。その結果、本材料のＡc3点は1040℃であることが判明した。
このことから、上記組織は、熱延板焼鈍をＡc3点以上で行ったことにより、熱延板焼鈍時に一旦オーステナイト域となり、冷却時のγ→α変態に伴うＣの溶解度量の低下により微細なセメンタイトが析出したものと考えられる。
Therefore, the Ac 3 transformation point of this material was investigated by measuring the coefficient of thermal expansion during a temperature rise of 30 ° C./s using a Formaster tester. As a result, the Ac 3 point of this material was found to be 1040 ° C.
From this, the above-mentioned structure is austenite region at the time of hot-rolled sheet annealing by performing hot-rolled sheet annealing at Ac 3 points or more, and it becomes finer due to a decrease in the solubility amount of C accompanying γ → α transformation at the time of cooling. It is thought that a lot of cementite was precipitated.
上記のような条件で、Ｃを比較的多量に含有する素材を熱延板焼鈍することにより、磁束密度が向上した理由は、明確に解明されたわけではないが、セメンタイトの第二相が存在することにより、セメンタイト周りからの再結晶が生じ、これにより、磁束密度に好ましい集合組織が形成されたためと考えられる。
一方、フェライト域で熱延板焼鈍を行う場合においても、本発明のようなオーステナイト域で熱延板焼鈍を行う場合ほどではないにしろ、多少なりともセメンタイトが形成される。しかしながら、このような場合は磁束密度はさほど向上しない。その理由としては、セメンタイト量の違いのみならず、フェライト域で熱延板焼鈍するときには、熱延板焼鈍後の結晶粒径が小さいため、冷延時に結晶粒内の変形帯が発達し難く、仕上焼鈍時には粒界から、好ましくない方位である｛１１１｝方位粒の発生が多くなるためと考えられる。
なお、かようなセメンタイトは、その後の脱炭焼鈍により、一旦鋼中に固溶された後、鋼中から除去される。
The reason why the magnetic flux density is improved by annealing a material containing a relatively large amount of C under the above conditions is not clearly clarified, but there is a second phase of cementite. This is considered to be because recrystallization from around the cementite occurred, and as a result, a texture favorable to the magnetic flux density was formed.
On the other hand, when hot-rolled sheet annealing is performed in the ferrite region, cementite is formed to some extent, if not as much as in the case of performing hot-rolled sheet annealing in the austenite region as in the present invention. However, in such a case, the magnetic flux density is not improved so much. The reason for this is not only the difference in the amount of cementite, but also when hot-rolled sheet annealing is performed in the ferrite region, because the crystal grain size after hot-rolled sheet annealing is small, it is difficult for the deformation bands in the crystal grains to develop during cold rolling, This is probably because the generation of {111} oriented grains, which are undesirable orientations, increases from the grain boundaries during finish annealing.
Such cementite is once dissolved in steel by subsequent decarburization annealing and then removed from the steel.
次に、熱延板焼鈍後の冷却速度の影響について調査するため、Ｃ：0.02％、Si：1.0％、Mn：0.18％、Ｐ：0.05％、Al：trおよびＮ：0.0015％を含有し、残部はFeおよび不可避的不純物の組成になる鋼を、真空溶解し、熱延後、1150℃，30ｓの熱延板焼鈍を行った。ついで、その後の冷却に際し、冷却速度を変化させるため、水冷、油冷、空冷および保温カバーを使用することにより、冷却速度を100℃/sから0.1℃/sまでの間で大きく変化させた。引き続き、板厚：0.5mmまで冷間圧延（25℃）を行い、20vol％H2−80vol％N2、露点：＋35℃の雰囲気中にて850℃、60ｓの脱炭焼鈍を行い、さらに25vol％H2−75vol％N2雰囲気中にて950℃、10ｓの仕上焼鈍を行った。 Next, in order to investigate the influence of the cooling rate after hot-rolled sheet annealing, C: 0.02%, Si: 1.0%, Mn: 0.18%, P: 0.05%, Al: tr and N: 0.0015%, The balance was Fe and an inevitable impurity steel, which was melted in vacuum and hot-rolled, followed by hot-rolled sheet annealing at 1150 ° C. for 30 seconds. Subsequently, in order to change the cooling rate during the subsequent cooling, the cooling rate was greatly changed from 100 ° C./s to 0.1 ° C./s by using water cooling, oil cooling, air cooling and a heat insulating cover. Subsequently, cold rolling (25 ° C) was performed to a thickness of 0.5mm, decarburization annealing was performed at 850 ° C for 60s in an atmosphere of 20vol% H 2 -80vol% N 2 and dew point: + 35 ° C, and further 25vol. Finish annealing was performed at 950 ° C. for 10 s in a% H 2 -75 vol% N 2 atmosphere.
図２に、熱延板焼鈍後の冷却速度と磁束密度との関係について調べた結果を示す。
同図から明らかなように、冷却速度が１℃/s以上で磁束密度が向上することが分かる。
In FIG. 2, the result of having investigated about the relationship between the cooling rate after hot-rolled sheet annealing and magnetic flux density is shown.
As is apparent from the figure, the magnetic flux density is improved when the cooling rate is 1 ° C./s or more.
この原因を調査するため、ＴＥＭ観察を行ってセメンタイトを調査したところ、冷却速度が１℃/s未満では、粒内のセメンタイトが少なく、主として粒界に析出していることが分かった。
一方、冷却速度が１℃/s以上では、粒内に多数のセメンタイトが認められ、特に50℃/s以上になると緻密に分散析出していることが明らかになった。
In order to investigate this cause, TEM observation was performed to investigate cementite, and it was found that when the cooling rate was less than 1 ° C./s, the cementite in the grains was small and mainly precipitated at the grain boundaries.
On the other hand, when the cooling rate was 1 ° C./s or more, a large number of cementite was observed in the grains, and when the cooling rate was 50 ° C./s or more, it was revealed that the particles were densely dispersed and precipitated.
上記の結果から、前記した磁束密度の向上は、以下のようにして生じたものと考えられる。
すなわち、冷却速度が１℃/s以上では、セメンタイトが粒内に緻密に分散するようになるため、その後の冷延でセメンタイト周りに転位が蓄積され、再結晶過程においては、このような場所が再結晶核の生成サイトとなって、粒内から磁気特性に好ましい方位の再結晶が優先的に起こる結果、高い磁束密度が得られたものと考えられる。
以上より、熱延板焼鈍後の冷却速度は１℃/s以上とした。より好ましくは50℃/s以上である。
From the above results, it is considered that the improvement of the magnetic flux density described above occurred as follows.
That is, when the cooling rate is 1 ° C./s or higher, cementite is densely dispersed in the grains, so that dislocations are accumulated around the cementite in the subsequent cold rolling, and such a place is present in the recrystallization process. It is considered that a high magnetic flux density was obtained as a result of recrystallization nucleation forming sites preferentially causing recrystallization in a direction suitable for magnetic properties from within the grains.
From the above, the cooling rate after hot-rolled sheet annealing was set to 1 ° C./s or more. More preferably, it is 50 ° C./s or more.
なお、冷却速度を制御する温度域を800℃〜500℃とする。これは、800℃〜500℃の領域がセメンタイトの析出する領域であると共に、この温度域ではＣの拡散が比較的早いことから、この領域において徐冷するとＣが粒界に析出し、粒内に析出するセメンタイト量が少なくなるためであり、800℃〜500℃の温度域を制御冷却することによって、高い磁束密度を得ることができるのである。 In addition, the temperature range which controls a cooling rate shall be 800 to 500 degreeC. This is because the region of 800 ° C. to 500 ° C. is a region where cementite is precipitated, and C diffusion is relatively fast in this temperature range. This is because the amount of cementite that precipitates on the surface decreases, and a high magnetic flux density can be obtained by controlled cooling in the temperature range of 800 ° C. to 500 ° C.
次に、発明者らは、適正なＣ量を調査するために、Ｃ：0.002〜0.2％、Si：1.0％、Mn：0.2％、Al：0.0010％、Ｐ：0.05％、Ｓ：0.0010％およびＮ：0.002％を含有し、残部はFeおよび不可避的不純物の組成になる鋼を、真空溶解し、熱延後、1150℃，30ｓの熱延板焼鈍を行ったのち、800〜500℃の間を平均冷却速度：60℃/sで冷却後、板厚：0.5mmまで冷間圧延（25℃）および温間圧延（150℃）した。引き続き、Ｃ量に応じて、20vol%H2−80vol%N2、露点：＋35℃の雰囲気中にて850℃，60〜1200ｓの脱炭焼鈍を行い、さらに25vol%H2−75vol%N2雰囲気中にて950℃，10ｓの仕上焼鈍を行った。 Next, the inventors examined C: 0.002 to 0.2%, Si: 1.0%, Mn: 0.2%, Al: 0.0010%, P: 0.05%, S: 0.0010% and N: 0.002% is contained, the balance is Fe and the inevitable impurities composition steel is melted in vacuum, hot-rolled, and then subjected to hot-rolled sheet annealing at 1150 ° C for 30s, then between 800-500 ° C After cooling at an average cooling rate of 60 ° C./s, it was cold-rolled (25 ° C.) and warm-rolled (150 ° C.) to a sheet thickness of 0.5 mm. Subsequently, decarburization annealing is performed at 850 ° C. for 60 to 1200 s in an atmosphere of 20 vol% H 2 −80 vol% N 2 and dew point: + 35 ° C. according to the amount of C, and further 25 vol% H 2 −75 vol% N 2 Finish annealing was performed at 950 ° C for 10 s in the atmosphere.
図３に、熱延板のＣ量と磁束密度との関係について調べた結果を示す。また、同図には、熱延板焼鈍後、冷間圧延に代えて、150℃の温間で圧延を行った場合の調査結果も併せて示す。
同図より明らかなように、Ｃ量が0.01％以上で磁束密度が向上することが分かる。
この理由は、Ｃ量が0.01％未満では、Ａc3変態点以上で熱延板焼鈍を行っても集合組織に影響を及ぼすほどのセメンタイトが析出しないためと考えられる。
また、同図に示したとおり、最終圧延を冷間圧延に代えて温間圧延とすることにより、磁束密度の一層の向上が達成されている。
In FIG. 3, the result of having investigated about the relationship between C amount of a hot-rolled sheet and magnetic flux density is shown. In addition, the figure also shows the results of investigation in the case of rolling at a temperature of 150 ° C. instead of cold rolling after hot-rolled sheet annealing.
As is apparent from the figure, the magnetic flux density is improved when the C content is 0.01% or more.
The reason for this is considered to be that when the C content is less than 0.01%, cementite that affects the texture does not precipitate even when hot-rolled sheet annealing is performed at the Ac 3 transformation point or higher.
In addition, as shown in the figure, the magnetic flux density is further improved by replacing the cold rolling with warm rolling instead of cold rolling.
そこで、次に発明者らは、磁束密度に及ぼす温間圧延温度の影響について調査するため、Ｃ：0.02％、Si：1.1％、Mn：0.18％、Al：tr、Ｐ：0.05％、Ｓ：0.0010％およびＮ：0.0018％を含有し、残部はFeおよび不可避的不純物の組成になる鋼を、真空溶解し、熱延後、1150℃，30ｓの熱延板焼鈍を行ったのち、800〜500℃の間を平均冷却速度：60℃/sで冷却後、板厚：0.5mmまで圧延温度：20〜400℃にて仕上圧延を行った。引き続き、20vol%H2−80vol%N2、露点：＋35℃の雰囲気中にて850℃，60ｓの脱炭焼鈍を行い、さらに25vol%H2−75vol%N2雰囲気中にて950℃，10ｓの仕上焼鈍を行った。 Therefore, the inventors next investigated C: 0.02%, Si: 1.1%, Mn: 0.18%, Al: tr, P: 0.05%, S: to investigate the influence of the warm rolling temperature on the magnetic flux density. A steel containing 0.0010% and N: 0.0018%, the balance being Fe and inevitable impurities, is melted in vacuum, hot-rolled, and then subjected to hot-rolled sheet annealing at 1150 ° C. for 30 seconds, followed by 800-500 After cooling at an average cooling rate of 60 ° C./s between ℃, finish rolling was performed at a rolling temperature of 20 to 400 ° C. to a sheet thickness of 0.5 mm. Subsequently, decarburization annealing was performed at 850 ° C. for 60 s in an atmosphere of 20 vol% H 2 −80 vol% N 2 and dew point: + 35 ° C., and further 950 ° C. for 10 s in 25 vol% H 2 −75 vol% N 2 atmosphere. Finish annealing was performed.
図４に、温間圧延温度と磁束密度との関係について調べた結果を示す。
同図に示したとおり、圧延温度を70℃以上とすることによって磁束密度が大幅に向上することが分かる。
このように、最終圧延を温間圧延とすることによって磁束密度が向上した理由は、圧延時の動的歪時効により磁気特性に好ましい集合組織が発達したためと考えられる。
In FIG. 4, the result of having investigated about the relationship between warm rolling temperature and magnetic flux density is shown.
As shown in the figure, it can be seen that the magnetic flux density is greatly improved by setting the rolling temperature to 70 ° C. or higher.
Thus, the reason why the magnetic flux density is improved by making the final rolling warm is considered to be that a texture favorable to magnetic properties has developed due to dynamic strain aging during rolling.
次に、本発明における鋼の好適成分組成範囲について説明する。
Ｃ：0.01〜0.2％
本発明では、鋼中に適量のパーライト組織を形成する必要上、少なくとも0.01％のＣを必要とする。好ましくは0.15％以上である。しかしながら、Ｃ量が0.2％超になると脱炭に長時間を要し、いたずらにコストアップを招くため、Ｃ量の上限は0.2％とした。
Si：３％以下
Siは、鋼板の固有抵抗を上げるために有効な元素であるが、３％を超えるとＡc3点超えの焼鈍が困難となるだけでなく、熱延板の変形抵抗が上昇して冷間圧延が難しくなる。このためSi量の上限は３％とした。
Mn：0.05〜3.0％
Mnは、熱間圧延時の赤熱脆性を防止する上で0.05％以上必要であるが、3.0％超になると磁束密度を低下させるので、0.05〜3.0％とした。
Al：１％以下
Alは、Siと同様、固有抵抗を上げるために有効な元素であるが、１％を超えるとＡc3点が高くなり、熱延板焼鈍においてオーステナイト域で焼鈍することが困難となるため、上限を１％とした。なお、このAlは、必要に応じて省略することもできる。
Ｐ：0.2％以下
Ｐは：鋼板の打ち抜き性を改善するために必要な元素であるが、0.2％を超えて添加すると鋼板が脆化するため：0.2％以下とした。
Ｓ：0.01％以下
Ｓは、0.01％を超えるとMnＳ等の硫化物量が多くなり、鉄損が増大するため、0.01％以下とした。
Ｎ：0.005％以下
Ｎは、0.005％超になると窒化物量が多くなり、鉄損が増大するため、0.005％以下とした。
Next, the preferred component composition range of the steel in the present invention will be described.
C: 0.01 to 0.2%
In the present invention, at least 0.01% of C is required for forming an appropriate amount of pearlite structure in steel. Preferably it is 0.15% or more. However, if the amount of C exceeds 0.2%, it takes a long time for decarburization and unnecessarily increases the cost. Therefore, the upper limit of the amount of C is set to 0.2%.
Si: 3% or less
Si is an effective element for increasing the specific resistance of the steel sheet, but if it exceeds 3%, not only annealing beyond the Ac 3 point becomes difficult, but the deformation resistance of the hot-rolled sheet increases and cold rolling is performed. Becomes difficult. For this reason, the upper limit of the amount of Si was made into 3%.
Mn: 0.05-3.0%
Mn is required to be 0.05% or more in order to prevent red hot brittleness during hot rolling, but if it exceeds 3.0%, the magnetic flux density is lowered, so 0.05 to 3.0% was set.
Al: 1% or less
Al, like Si, is an effective element for increasing the specific resistance. However, if it exceeds 1%, the Ac 3 point becomes high, and it becomes difficult to anneal in the austenite region in hot-rolled sheet annealing. Was 1%. In addition, this Al can also be abbreviate | omitted as needed.
P: 0.2% or less P: An element necessary for improving the punchability of the steel sheet, but if added over 0.2%, the steel sheet becomes brittle: 0.2% or less.
S: 0.01% or less If S exceeds 0.01%, the amount of sulfides such as MnS increases and the iron loss increases.
N: 0.005% or less N is 0.005% or less because if N exceeds 0.005%, the amount of nitride increases and iron loss increases.
以上、基本成分について説明したが、本発明では、その他にも磁気特性向上の観点からSb，Sn，Ni，Cr，CoおよびCu等を適宜添加することができる。
これら元素の好ましい添加範囲は次のとおりである。
Sb：0.005〜0.05％
Sn：0.005〜0.1％
Ni：0.1〜５％
Cr：0.5〜５％
Co：0.1〜10％
Cu：0.01〜１％
Although the basic components have been described above, in the present invention, Sb, Sn, Ni, Cr, Co, Cu, and the like can be appropriately added from the viewpoint of improving the magnetic characteristics.
The preferable addition range of these elements is as follows.
Sb: 0.005-0.05%
Sn: 0.005-0.1%
Ni: 0.1-5%
Cr: 0.5-5%
Co: 0.1-10%
Cu: 0.01 to 1%
次に、本発明に従う無方向性電磁鋼板の製造方法について説明する。
本発明の無方向性電磁鋼板は、成分および熱延板焼鈍条件、さらには温間圧延条件が所定の範囲内であれば、他の製造工程は特に限定されず、通常の方法で構わない。
すなわち、本発明の鋼板を得るには、転炉で吹練した溶鋼を脱ガス処理し所定の成分に調整し、引き続き鋳造、熱間圧延を行う。この時、熱間圧延時の仕上焼鈍温度、巻取り温度は特に規定する必要はなく、通常でかまわない。
Next, the manufacturing method of the non-oriented electrical steel sheet according to the present invention will be described.
The non-oriented electrical steel sheet of the present invention is not particularly limited as long as the components, hot-rolled sheet annealing conditions, and warm-rolling conditions are within a predetermined range, and may be a normal method.
That is, in order to obtain the steel sheet of the present invention, the molten steel blown in the converter is degassed and adjusted to a predetermined component, followed by casting and hot rolling. At this time, the finish annealing temperature and the coiling temperature at the time of hot rolling do not need to be particularly defined, and may be normal.
ついで、熱間圧延後、熱延板焼鈍を行う。この熱延板焼鈍温度は成分により決まるＡc3変態点以上の温度とする。
というのは、熱延板焼鈍温度が、Ａc3変態点未満では、前掲図１に示したように、良好な磁束密度の改善が望めないからである。なお、熱延板焼鈍温度の上限は特に限定されることはないが、あまりに高温では鋼板の強度が低下し、通板が困難となるので、1250℃以下程度とするのが好ましい。
また、熱延板焼鈍時間も特に限定されることはないが、10ｓ以上の焼鈍により安定した冷間（温間）圧延前組織とすることができる。
Next, hot rolling is performed after hot rolling. This hot-rolled sheet annealing temperature is set to a temperature equal to or higher than the Ac 3 transformation point determined by the components.
This is because, if the hot-rolled sheet annealing temperature is lower than the Ac 3 transformation point, as shown in FIG. 1, good magnetic flux density improvement cannot be expected. The upper limit of the hot-rolled sheet annealing temperature is not particularly limited, but it is preferably set to about 1250 ° C. or lower because the strength of the steel sheet is lowered at too high a temperature and it becomes difficult to pass the sheet.
Moreover, although the hot-rolled sheet annealing time is not particularly limited, a stable structure before cold (warm) rolling can be obtained by annealing for 10 seconds or more.
次に、熱延板焼鈍後、少なくとも800〜500℃間の平均冷却速度は１℃/s以上とする。ここで、平均冷却速度とは、800℃から500℃までの300℃の温度域の冷却を、その間の冷却に要した時間で除したものとする。なお、制御温度域が800℃超では、Ｃが鋼中にほとんど固溶しているため、冷却速度を変化させることによる磁束密度の改善効果が望めず、一方500℃未満ではＣの拡散速度が遅くなるため、冷却速度を変化させてもセメンタイトの分散状態がほとんど変化しない。 Next, after the hot-rolled sheet annealing, the average cooling rate between at least 800 to 500 ° C. is set to 1 ° C./s or more. Here, the average cooling rate is obtained by dividing the cooling in the temperature range of 300 ° C. from 800 ° C. to 500 ° C. by the time required for the cooling in the meantime. When the control temperature range is over 800 ° C, C is almost dissolved in the steel, so the effect of improving the magnetic flux density by changing the cooling rate cannot be expected. Since it becomes slow, the dispersion state of cementite hardly changes even when the cooling rate is changed.
引き続き、冷間もしくは温間にて最終板厚まで圧延を行うが、特に70〜400℃の温間で圧延することにより、より一層磁束密度を向上させることができる。
すなわち、前掲図４に示したように、圧延温度が70℃以上になると、磁束密度が大幅に改善される。そこで、温間圧延時における温度の下限は70℃とした。より好ましくは100℃以上である。なお、温間圧延温度が400℃を超えても磁束密度の向上効果はあるが、いたずらにコストアップを招くため、温間圧延時における温度の上限は400℃とした。
Subsequently, the steel sheet is rolled to the final thickness in the cold or warm state, and the magnetic flux density can be further improved by rolling at a particularly high temperature of 70 to 400 ° C.
That is, as shown in FIG. 4, when the rolling temperature is 70 ° C. or higher, the magnetic flux density is greatly improved. Therefore, the lower limit of the temperature during warm rolling was set to 70 ° C. More preferably, it is 100 ° C. or higher. Note that even if the warm rolling temperature exceeds 400 ° C., there is an effect of improving the magnetic flux density, but since the cost is unnecessarily increased, the upper limit of the temperature during the warm rolling is set to 400 ° C.
その後、鋼中Ｃ量に応じた脱炭焼鈍を施したのち、所定の磁気特性を得るための仕上焼鈍を行って製品とする。ここで、脱炭焼鈍の好適条件は、焼鈍温度：700〜900℃、焼鈍時間：30ｓ〜１ｈ、露点：10〜40℃である。 Then, after performing decarburization annealing according to the amount of C in steel, finish annealing for obtaining predetermined magnetic properties is performed to obtain a product. Here, suitable conditions for decarburization annealing are annealing temperature: 700 to 900 ° C., annealing time: 30 s to 1 h, and dew point: 10 to 40 ° C.
表１または表３に示す成分組成になる鋼を、転炉吹練および脱ガス処理により溶製し、連続鋳造後、得られたスラブを1200℃で１ｈ加熱したのち、板厚：2.6mmまで熱間圧延した。熱延仕上げ温度は830℃、巻取り温度は610℃とした。
ついで、表２または表４に示す条件で、熱延板焼鈍後、板厚：0.5mmまでの冷間（25℃）または温間（50〜350℃）で圧延したのち、脱炭焼鈍および仕上焼鈍を行って、無方向性電磁鋼板とした。
かくして得られた電磁鋼板の磁気特性について調べた結果を、表２または表４に併記する。
なお、磁気測定は、25cmエプスタイン試験片を用いて行った。また、表中のＡc3点は、フォーマスター試験機にて30℃/sでサンプルを加熱した際の熱膨張率を測定することにより求めた。
Steel having the composition shown in Table 1 or 3 is melted by converter blowing and degassing treatment, and after continuous casting, the obtained slab is heated at 1200 ° C for 1 h, and then the plate thickness: 2.6 mm Hot rolled. The hot rolling finishing temperature was 830 ° C and the winding temperature was 610 ° C.
Next, after hot-rolled sheet annealing under the conditions shown in Table 2 or Table 4, the sheet thickness is rolled to cold (25 ° C) or warm (50-350 ° C) up to 0.5mm, and then decarburized annealing and finishing. Annealing was performed to obtain a non-oriented electrical steel sheet.
The results of examining the magnetic properties of the electrical steel sheet thus obtained are also shown in Table 2 or Table 4.
Magnetic measurement was performed using a 25 cm Epstein test piece. The Ac 3 point in the table was determined by measuring the coefficient of thermal expansion when the sample was heated at 30 ° C./s with a Formaster tester.
表１〜表４から明らかなように、鋼成分および熱延板焼鈍条件を本発明の適正範囲に制御した発明例はいずれも、高い磁束密度と低い鉄損が併せて得られており、特に最終圧延として温間圧延を利用した場合や熱延板焼鈍後の冷却速度を本発明の範囲内とした場合は一層優れた磁気特性を得ることができた。
これに対し、鋼成分および熱延板焼鈍条件の一方または両方が、本発明の適正範囲から逸脱した比較例はいずれも、少なくとも磁束密度か鉄損のいずれかが十分でなく、発明例に比べると劣った磁気特性しか得られなかった。
As is apparent from Tables 1 to 4, all of the inventive examples in which the steel components and the hot-rolled sheet annealing conditions are controlled within the appropriate range of the present invention have both high magnetic flux density and low iron loss. When warm rolling was used as the final rolling or when the cooling rate after hot-rolled sheet annealing was within the range of the present invention, more excellent magnetic properties could be obtained.
On the other hand, in any of the comparative examples in which one or both of the steel component and the hot-rolled sheet annealing condition deviate from the appropriate range of the present invention, at least either the magnetic flux density or the iron loss is not sufficient, and compared with the inventive example. Only inferior magnetic properties were obtained.
Claims (2)
Ｃ：0.01〜0.2％、
Si：３％以下、
Mn：0.05〜3.0％、
Al：１％以下、
Ｐ：0.2％以下、
Ｓ：0.01％以下および
Ｎ：0.005％以下
を含み、残部はFeおよび不可避不純物の組成になる鋼材を、熱間圧延し、熱延板焼鈍後、最終板厚まで圧延し、ついで脱炭焼鈍および仕上焼鈍を施す一連の工程によって無方向性電磁鋼板を製造するに際し、熱延板焼鈍をＡc3点以上の温度域で行い、該熱延板焼鈍後、少なくとも800〜500℃の温度域を平均冷却速度：１℃/s以上で冷却することを特徴とする磁気特性に優れた無方向性電磁鋼板の製造方法。 % By mass
C: 0.01-0.2%
Si: 3% or less,
Mn: 0.05-3.0%
Al: 1% or less,
P: 0.2% or less,
S: 0.01% or less and N: 0.005% or less, with the balance being Fe and unavoidable impurities, hot rolled, hot-rolled sheet annealed, rolled to final thickness, then decarburized annealed and When producing a non-oriented electrical steel sheet by a series of processes for performing finish annealing, hot-rolled sheet annealing is performed in a temperature range of Ac 3 points or more, and after the hot-rolled sheet annealing, a temperature range of at least 800 to 500 ° C is averaged. A method for producing a non-oriented electrical steel sheet having excellent magnetic properties, characterized by cooling at a cooling rate of 1 ° C./s or more.
Ｃ：0.01〜0.2％、
Si：３％以下、
Mn：0.05〜3.0％、
Al：１％以下、
Ｐ：0.2％以下、
Ｓ：0.01％以下および
Ｎ：0.005％以下
を含み、残部はFeおよび不可避不純物の組成になる鋼材を、熱間圧延し、熱延板焼鈍後、最終板厚まで圧延し、ついで脱炭焼鈍および仕上焼鈍を施す一連の工程によって無方向性電磁鋼板を製造するに際し、熱延板焼鈍をＡc3点以上の温度域で行い、該熱延板焼鈍後、少なくとも800〜500℃の温度域を平均冷却速度：１℃/s以上で冷却し、引き続き70〜400℃の温度域にて温間圧延を行うことを特徴とする磁気特性に優れた無方向性電磁鋼板の製造方法。 % By mass
C: 0.01-0.2%
Si: 3% or less,
Mn: 0.05-3.0%
Al: 1% or less,
P: 0.2% or less,
S: 0.01% or less and N: 0.005% or less, with the balance being Fe and unavoidable impurities, hot rolled, hot-rolled sheet annealed, rolled to final thickness, then decarburized annealed and When producing a non-oriented electrical steel sheet by a series of processes for performing finish annealing, hot-rolled sheet annealing is performed in a temperature range of Ac 3 points or more, and after the hot-rolled sheet annealing, a temperature range of at least 800 to 500 ° C is averaged. A method for producing a non-oriented electrical steel sheet excellent in magnetic properties, characterized by cooling at a cooling rate of 1 ° C./s or more and subsequently performing warm rolling in a temperature range of 70 to 400 ° C.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004377135A JP4613611B2 (en) | 2004-08-04 | 2004-12-27 | Method for producing non-oriented electrical steel sheet |
| KR1020050071093A KR100683471B1 (en) | 2004-08-04 | 2005-08-03 | Method for processing non-directional electromagnetic steel plate and hot rolling steel plate with material for the non-directional electromagnetic steel plate |
| CN200510088542XA CN1803389B (en) | 2004-08-04 | 2005-08-04 | Method for manufacturing non-oriented electromagnetic steel sheet, and raw material hot rolling steel sheet |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004228256 | 2004-08-04 | ||
| JP2004377135A JP4613611B2 (en) | 2004-08-04 | 2004-12-27 | Method for producing non-oriented electrical steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2006070356A JP2006070356A (en) | 2006-03-16 |
| JP4613611B2 true JP4613611B2 (en) | 2011-01-19 |
Family
ID=36151285
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2004377135A Expired - Fee Related JP4613611B2 (en) | 2004-08-04 | 2004-12-27 | Method for producing non-oriented electrical steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4613611B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114729415B (en) * | 2019-11-12 | 2024-02-13 | Lg电子株式会社 | Non-oriented electrical steel sheet and method for producing same |
| BR112022011835A2 (en) * | 2020-02-20 | 2022-08-30 | Nippon Steel Corp | HOT LAMINATED STEEL SHEET FOR A NON-ORIENTED ELECTRIC STEEL SHEET |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58157917A (en) * | 1982-03-15 | 1983-09-20 | Kawasaki Steel Corp | Manufacture of unidirectional silicon steel plate with superior magnetic characteristic |
| JP2001158950A (en) * | 1999-12-03 | 2001-06-12 | Kawasaki Steel Corp | Silicon steel sheet for small-size electrical equipment, and its manufacturing method |
-
2004
- 2004-12-27 JP JP2004377135A patent/JP4613611B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58157917A (en) * | 1982-03-15 | 1983-09-20 | Kawasaki Steel Corp | Manufacture of unidirectional silicon steel plate with superior magnetic characteristic |
| JP2001158950A (en) * | 1999-12-03 | 2001-06-12 | Kawasaki Steel Corp | Silicon steel sheet for small-size electrical equipment, and its manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2006070356A (en) | 2006-03-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5892327B2 (en) | Method for producing non-oriented electrical steel sheet | |
| JP5991484B2 (en) | Manufacturing method of low iron loss grain oriented electrical steel sheet | |
| WO1986007390A1 (en) | Process for producing silicon steel sheet having soft magnetic characteristics | |
| KR100683471B1 (en) | Method for processing non-directional electromagnetic steel plate and hot rolling steel plate with material for the non-directional electromagnetic steel plate | |
| JP5853983B2 (en) | Method for producing hot-rolled steel sheet for non-oriented electrical steel sheet and method for producing non-oriented electrical steel sheet | |
| JP5287615B2 (en) | Method for producing grain-oriented electrical steel sheet | |
| JP4207231B2 (en) | Method for producing non-oriented electrical steel sheet | |
| JP7159595B2 (en) | Manufacturing method of grain-oriented electrical steel sheet | |
| JP2020056105A (en) | Method for manufacturing grain-oriented electrical steel sheet | |
| JP4701669B2 (en) | Method for producing non-oriented electrical steel sheet | |
| JP4613611B2 (en) | Method for producing non-oriented electrical steel sheet | |
| JP2015212403A (en) | Method for manufacturing nonoriented electromagnetic steel sheet | |
| JP2007177282A (en) | Method for producing nonoriented electromagnetic steel sheet having high magnetic flux density | |
| JP7081725B1 (en) | Manufacturing method of grain-oriented electrical steel sheet | |
| KR100370547B1 (en) | Non-oriented electrical steel sheet excellent in permeability and method of producing the same | |
| JPH10226819A (en) | Production of grain oriented silicon steel sheet excellent in core loss characteristic | |
| JP4013262B2 (en) | Non-oriented electrical steel sheet and manufacturing method thereof | |
| JP7525081B1 (en) | Non-oriented electrical steel sheet and its manufacturing method | |
| JP7415135B2 (en) | Manufacturing method of non-oriented electrical steel sheet | |
| KR100241005B1 (en) | The manufacturing method of oriented electric steel sheet with only one cold rolling processed | |
| KR100721818B1 (en) | Non-oriented electrical steel sheets with excellent magnetic properties and method for manufacturing the same | |
| JPH06240358A (en) | Production of nonoriented silicon steel sheet high in magnetic flux density and low in iron loss | |
| JPH07113120A (en) | Production of grain oriented silicon steel sheet reduced in iron loss and having high magnetic flux density | |
| JPS60190521A (en) | Manufacture of nonoriented electrical steel sheet | |
| KR100721926B1 (en) | Non-oriented electrical steel sheets with excellent magnetic properties and method for manufacturing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20060608 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20070927 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20090602 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20090803 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20090803 |
|
| 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: 20100921 |
|
| 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: 20101004 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4613611 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131029 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |