JP3734191B2 - Component adjustment method for annealing separator for grain-oriented electrical steel sheet - Google Patents

Description

【００１６】
この場合において、焼鈍分離剤はＭｇＯ１００重量部に対しＳｎＯ_２を無添加とした場合および５重量部添加した場合とし、最終仕上げ焼鈍を施すにあたり加熱速度１０℃／ｈで行う加熱過程を、Ｈ_２およびＮ_２の混合雰囲気のみで行う場合（条件１）と、８００℃までＮ_２のみで行い、その後Ｈ_２よびＮ_２の混合雰囲気に切り替えて行う場合（条件２）に分けて行った。なお、１１８０℃到達後、Ｈ_２中で５ｈの純化焼鈍を施した。表２に、これらの条件で得られた磁気特性と被膜特性を示した。
【００１７】
実験１の結果より、０．０２≦ｓｏｌ．Ａｌ（％）≦０．０３の範囲でＭｇＯを主成分とする焼鈍分離剤中にＳｎＯ_２を添加すると、良好な磁気特性が得られることがわかった。２次再結晶組織を観察すると、ｓｏｌ．Ａｌの少ないＡ鋼では２次再結晶は行なわれたが、ゴス方位への集積度が低いため、磁束密度Ｂ_８の値が低かった。一方ｓｏｌ．Ａｌの多いＥ鋼では二次再結晶せず微細組織となった。従って、ｓｏｌ．Ａｌ量は、０．０２％以上、０．０３％以下とする必要がある。
【００１８】
【表２】

【００１９】
上記実験から、またＳｎＯ_２の添加により被膜特性は常に改善されることもわかった。そしてその場合、焼鈍雰囲気を途中まで、この場合８００℃まで、Ｎ_２雰囲気にすると、さらに磁気特性が良好になることがわかった。これは、最終焼鈍過程において８００℃までＮ_２雰囲気で行ったため、ＳｎＯ_２の分解を遅らせることができ、Ｈ_２導入後、分解したＳｎあるいはＯが有効に作用したためであると考えられる。
【００２０】
〔実験２〕
表３に示すようにｓｏｌ．Ａｌはほぼ一定レベルに保ちながら、Ｎ量を変化させて組成の鋼を実験室で真空溶製し、１３５０℃で３０分加熱後熱間圧延し、２．２ｍｍの板厚に仕上げ、１０００℃で熱延板焼鈍を施した後、酸洗し、１１００℃の中間焼鈍を挟む２回の冷間圧延と温間圧延を組み合わせて０．２２ｍｍに仕上げた。その後、８５０℃で２分間湿水素中で脱炭焼鈍し、ＭｇＯを主成分とする焼鈍分離剤を塗布し最終仕上げ焼鈍を施した。
【００２１】
【表３】

【００２２】
この場合において、焼鈍分離剤はＭｇＯ１００重量部にＳｎＯ_２を０．５〜１５重量部添加したものを用い、最終焼鈍の加熱速度は１０℃／ｈとし、その雰囲気を８５０℃までＮ_２、その後Ｈ_２、およびＮ_２の混合雰囲気とし、純化焼鈍はＨ_２中で１１８０℃において５ｈ施した。表４に、このときの磁気特性と被膜特性を示した。
【００２３】
【表４】

【００２４】
実験２の結果より、０．００６５≦Ｎ（％）≦０．００９５の範囲でＭｇＯ１００重量部に対して１重量部以上、１０重量部以下のＳｎＯ_２を添加すると、良好な磁気特性が得られることがわかった。被膜特性についてもその添加量が１重量部未満では耐剥離性が劣化し、１０重量部超えでは点状の欠陥が生じ耐剥離性が著しく劣化した。２次再結晶組織を観察すると、Ｎの少ないＦ鋼では２次再結晶せず微細組織となった。一方、Ｎの多いＪ鋼では、２次再結晶しているものの、その方位が悪く磁束密度が低かった。
【００２５】
ここで、先の実験１と併せ考えるとｓｏｌ．Ａｌ、Ｎの好適な範囲内においても、その比率により２次再結晶不良の形態が異なり、ＭｇＯ中のＳｎＯ_２の添加量に最適値があり、Ａｌ／Ｎを指標に整理して見るとＡｌ／Ｎが高いほどＳｎＯ_２の添加量を減少させる必要であることがわかった。
【００２６】
〔実験３〕
表５に示すように、ｓｏｌ．ＡｌおよびＮについて本発明の適正範囲を満たす組成の鋼を実験室で真空溶製し、１３５０℃で３０分間加熱後熱間圧延し、２．２ｍｍの板厚に仕上げ、１０００℃で熱延板焼鈍を施した後、酸洗し、１１００℃の中間焼鈍を挟む２回の冷間圧延と温間圧延を組み合わせて０．２２ｍｍに仕上げた。その後、８５０℃で２分間湿水素中で脱炭焼鈍し、ＭｇＯを主成分とする焼鈍分離剤を塗布し最終仕上げ焼鈍を施した。【００２７】
この場合において、ＭｇＯを主成分とする焼鈍分離剤中にＭｇＯ１００重量部に対してＳｎＯ_２を３重量部添加し、最終焼鈍を７００〜９００℃まで５℃／ｈの徐加熱とし、途中までＮ_２、その後Ｈ_２およびＮ_２の混合雰囲気とし、さらに１１８０℃到達後、Ｈ_２に切り換え、その温度で５ｈの純化焼鈍を施した。表６に、このときの磁気特性と被膜特性を示した。
【００２８】
【表５】

【００２９】
【表６】

【００３０】
実験３の結果より、ＡｌＮと公知のインヒビター元素を組み合わせて用いる場合にもＳｎＯ_２添加による効果が得られることがわかった。すなわち、焼鈍分離剤中にＳｎＯ_２を添加するときでもＳｅ、Ｓ、Ｃｕ、Ｓｂ、ＢｉなどＡｌＮとの併用が可能なことが確認された。また、本実験で、焼鈍雰囲気を７５０℃までＮ_２雰囲気にすること、かつ９００℃までにＮ_２＋Ｈ_２混合雰囲気に切り替えることでフォルステライト被膜の粒径が小さくなることが観察された。耐剥離性の改善はこのフォルステライト被膜の粒径の微細化に伴って生じたものと推定され、またそれに伴って良好な磁気特性が得られたと考えられる。
【００３１】
上記の切り替え温度が低すぎる場合には、ＳｎＯ_２がＨ_２により還元分解され、分解したＳｎ又はＯが被膜形成に有効に作用する前にＭｇＯの持ち込む水分により消費されてしまうため効果を失い、一方、切り替え温度が高すぎるとＳｎＯ_２の分解が遅れＳｎＯ_２添加による被膜改善効果が生じないことになると考えられる。従って、切り換え温度は重要であって、およそ以下の範囲を目安にすべきである。
Ｎ_２雰囲気からＮ_２及びＨ_２の混合雰囲気への切換：７５０℃以上、８５０℃以下
Ｎ_２及びＨ_２の混合雰囲気からＨ_２雰囲気への切換：１０００℃以上、１１００℃以下
【００３２】
上記の実験結果が示すようにＡｌ／Ｎが大きくなるに従いＳｎＯ_２添加量を減少させる場合には、製品磁気特性が安定して改善されるが、その原因について本発明者らはおよそ以下のように考えている。すなわち、ＭｇＯ中に添加したＳｎＯ_２は最終焼鈍中にＨ_２によりＳｎとＯに分解されるが、Ｓｎは比較的低融点のためＭｇＯ界面の塗れ性を高め、脱炭焼鈍により鋼板表面に生成したサブスケールとＭｇＯの固相−固相反応を促進し、フォルステライトの核生成頻度を高め、このため被膜特性が改善される。このとき、ＳｎＯ_２が多い場合にはＯの放出も多くなり、コイル層間の雰囲気圧力が高くなる。したがって、Ａｌ／Ｎが大きくなるに従いＳｎＯ_２量を少くすれば、鋼中への吸Ｎ量を増加させることができ、これによりインヒビターの機能を最適化できるものと推定される。換言すればＡｌ／Ｎが大きく、比較的ＡｌＮの粗大な分散系に対しては吸Ｎ量を増して、微細なＡｌＮを増し、Ａｌ／Ｎが小さく、ＡｌＮの微細な分散系に対しては吸Ｎ量を減らして、微細なＡｌＮの量を抑制することができたものと考えられる。
【００３３】
この発明の対象とする方向性電磁鋼板素材として代表的組成範囲を挙げると以下のとおりである。
Ｃ：０．０３％以上、０．１０％以下：
Ｃは熱延組織、冷延組織の均一微細化のみならず、ゴス方位の発達に有用な元素であり、少なくとも０．０３％は必要である。しかしながら、０．１０％を超えると後工程での脱炭が困難となるばかりでなく、かえってゴス方位の分散を招くので上限を０．１０％とする。
【００３４】
Ｓｉ：２．５％以上，４．５％以下：
Ｓｉは鋼板の比抵抗を高め鉄損の低減に寄与するが、４．５％を超えると冷延性が著しく損なわれるため４．５％を上限とする。一方、２．５％に満たないと比抵抗が低下するばかりでなく、最終仕上げ焼鈍中にα−γ変態により結晶方位がランダム化し、磁気特性を損なうので２．５％を下限とする。
【００３５】
Ｍｎ：０．０２％以上，０．１２％以下：
Ｍｎは熱間脆性を防止するためには少なくとも０．０２％を必要とするが、あまり多すぎるとＭｎＳｅ、ＭｎＳの微細分散を阻害し、磁気特性を劣化させるので上限を０．１２％とする。
【００３６】
Ｓｅ、Ｓの内から選ばれる少なくとも１種：０．０１％以上、０．０４％以下：
Ｓｅ、Ｓはいずも方向性珪素鋼の２次再結晶を抑制する有力な元素である。抑制力の点からは、少なくとも０．０１％は必要あるが、０．０４％を超えると微細析出を制御するのが困難なため、これらの値をそれぞれ上下限とする。
【００３７】
インヒビター成分：ｓｏｌ．Ａｌ：０．０２％以上、０．０３％以下、Ｎ：０．００６５％以上、０．００９５％以下：
ＡｌおよびＮの範囲についても前述したように良好な２次再結晶組織を得るために上記範囲に定めた。インヒビターとしては、ＡｌＮのほかＭｎＳｅ、ＭｎＳの内から選ばれる１種又は２種を併用して用いることが可能である。更に、上記したＭｎ、Ｓｅ、Ｓ、Ａｌ、Ｎのほか、Ｃｕ、Ｓｎ、Ｓｂ、Ｂｉなども有利に作用するのでそれぞれ併せて含有させることができる。これらの成分の好適範囲は、それぞれＣｕ、Ｓｎ：０．０５％以上、０．２５％以下、Ｓｂ、Ｂｉ：０．０１％以上、０．０５％以下であり、これらの１種又は２種以上の添加が可能である。
【００３８】
なお、本発明においては、焼鈍分離剤はＭｇＯを主体にこれにＳｎＯ_２を添加したものを用いるが、公知のＴｉやＳｒ化合物を目的に応じてＭｇＯ中へ微量添加することは本発明の効果を損なわないばかりか、むしろ相補的な効果を生ずるので好ましい。
【００３９】
【実施例】
【実施例１】
以下の組成を有するＰ鋼およびＱ鋼を溶製し、スラブとなし、１４２０℃で均熱後、２．２ｍｍ厚に仕上げ、１０００℃で熱延板焼鈍、酸洗を施し、１回目の冷延を施した後、１１００℃で中間焼鈍を行い、２００℃の温間圧延を含む２回目の圧延で０．２２ｍｍに仕上げた。さらに、磁区細分化を目的にエッチング法により探さ２０μｍの溝を幅方向に５ｍｍピッチで導入した。その後８５０℃での脱炭焼鈍を施し、ＭｇＯ１００重量部に対してＳｎＯ_２を０重量部、２．６重量部の各レベルで、更にＴｉＯ_２を８重量部、Ｓｒ（ＯＨ）_２を３重量部添加してなる焼鈍分離剤を塗布し、８３０℃までＮ_２雰囲気、その後Ｎ_２とＨ_２の混合雰囲気で１０℃／ｈの速度で加熱し、１１８０℃到達後Ｈ_２中で５ｈの純化焼鈍を施した。このときの磁気特性と被膜特性の結果を表７に示す。
【００４０】
〔Ｐ鋼〕
Ｃ：０．０７０％、Ｓｉ：３．３２％、Ｍｎ：０．０７１％、
Ｓｅ：０．０１８％、ｓｏｌ．Ａｌ：０．０２３％、Ｎ：０．００８５％、
Ａｌ／Ｎ：２．７１、Ｓｂ：０．０２６％、Ｃｕ：０．１１％
〔Ｑ鋼〕
Ｃ：０．０７２％、Ｓｉ：３．２５％、Ｍｎ：０．０６8％、
Ｓｅ：０．０４７％、ｓｏｌ．Ａｌ：０．０２６％、Ｎ：０．００８０％、
Ａｌ／Ｎ：３．２５、Ｓｂ：０．０２７％、Ｃｕ：０．１２％
【００４１】
【表７】

【００４２】
Ｐ鋼とＱ鋼を比較したとき後者のほうがＡｌ／Ｎ比が大きい。したがって、Ｐ鋼の場合、焼鈍分離剤中に添加したＳｎＯ_２の量をＱ鋼の場合に比べて多くすることによって、いずれの場合にも高い磁気特性を得ることができた。
【００４３】
【実施例２】
以下の組成を有するＲ鋼およびＳ鋼を溶製し、スラブとなし、１４２０℃で３０分均熱後、２．５mm厚に仕上げ、１１５０℃で熱延板焼鈍、酸洗を施し、２００℃の温間圧延を含む１回の圧延で０．２９ｍｍに仕上げた。その後８５０℃での脱炭焼鈍を施し、ＭｇＯ１００重量部に対してＳｎＯ_２を０重量部、３．８重量部の各レベルで、更にＴｉＯ_２を１０重量部、Ｓｒ（ＯＨ）_２を３重量部を添加してなる焼鈍分離剤を塗布し、８２０℃までＮ_２雰囲気、その後Ｎ_２とＨ_２の混合雰囲気で１０℃／ｈで加熱し１１８０℃到達後Ｈ_２中で５ｈの純化焼鈍を施した。このときの磁気特性と被膜特性の結果を表８に示す。
【００４４】
〔Ｒ鋼〕
Ｃ：０．０７３％、Ｓｉ：３．２７％、Ｍｎ：０．０６５％、
Ｓｅ：０．０１８％、ｓｏｌ．Ａｌ：０．０２３％、Ｎ：０．００８８％、
Ａｌ／Ｎ：２．６１、Ｓｂ：０．０３８％、Ｃｕ：０．０７％
〔Ｓ鋼〕
Ｃ：０．０６８％、Ｓｉ：３．２４％、Ｍｎ：０．０６８％、
Ｓｅ：０．０１７％、ｓｏｌ．Ａｌ：０．０２６％、Ｎ：０．００７４％、Ａｌ／Ｎ：３．５１、Ｓｂ：０．０４２％、Ｃｕ：０．０８％
【００４５】
【表８】

【００４６】
実施例1と同様にＲ鋼とＳ鋼のＡｌ／Ｎ比の相違に基づき焼鈍分離剤中へのＳｎＯ_２添加量を変えることにより、常に高い磁気特性を有しかつ、曲げ剥離性で評価される被膜特性を有する電磁鋼板を得ることができた。
【００４７】
【発明の効果】
本発明は、以上に説明したように構成したので、ＡｌＮをインヒビターとして用いる方向性電磁鋼板の製造の際のＡｌ／Ｎ比の変動にもかかわらず、特性値を極めて安定なものとすることができ、高い磁気特性を有する電磁鋼板を常に高い収率で生産することができる。また、被膜特性も向上し、これにより、磁気特性のさらなる向上が行なわれる。[0001]
[Industrial application fields]
The present invention relates to a component adjustment method for an annealing separator for grain- oriented electrical steel sheets. Specifically, it is related with the component adjustment method of the annealing separator for manufacturing the grain- oriented electrical steel sheet which has the especially outstanding magnetic characteristic and film characteristic by regulating the relationship between an annealing separator and a steel plate composition.
[0002]
[Prior art]
Oriented electrical steel sheets are mainly used as iron core materials for transformers and other electrical equipment, and are required to have excellent magnetic properties such as magnetic flux density and iron loss value. Recently, for example, a magnetic flux density B ₈ when magnetized at 800 A / m at a thickness of 0.23 mm is 1.90 T or more, an iron loss W _{17/50 at} a commercial frequency of 50 Hz, and a magnetic flux density of 1.7 _T is 0.90 W / Products reaching kg or less have also been put into practical use.
[0003]
In order to obtain such good characteristics, it is particularly necessary to secondarily recrystallize the structure of the electromagnetic steel sheet in the {110} <001> orientation, so-called Goth orientation. For this reason, various research improvements have been made and today, but in particular, it is essential to control fine precipitates called inhibitors in order to suppress normal growth of primary recrystallization and secondary recrystallization in a preferred orientation.
[0004]
As typical inhibitors, MnSe, MnS, AlN and the like are known. In particular, when AlN is used, an electromagnetic steel sheet having an extremely high magnetic flux density can be obtained, and by applying a magnetic domain fragmentation technique that has been put into practical use in recent years to this, it can have extremely excellent magnetic properties. . However, when AlN is used as an inhibitor, it is difficult to form a film or a characteristic secondary recrystallization failure tends to occur, and there is still room for improvement in terms of manufacturing stability.
[0005]
In order to solve this problem, it is known to use an annealing separator containing Sn. For example, Japanese Patent Publication No. 54-14567 discloses a precipitation state of AlN by limiting the absorption of N into steel by adding a compound such as Cu, Sn, Ni, Co or the like into MgO in the MgO coating step before final finish annealing. However, it is not always possible to completely stabilize the magnetic characteristics, and further improvement is required.
[0006]
On the other hand, Japanese Patent Publication No. 62-53576 or Japanese Patent Laid-Open No. 6-116644 discloses a sol. Proposals have been made to change the manufacturing conditions in accordance with the amount of Al. All of these methods are sol. This is a measure against a large fluctuation of Al. However, the countermeasures shown here require a change in conditions in a lower process with a large time constant such as a continuous annealing line, which increases the unsteady part and hinders productivity, and magnetic properties. There is a problem that it may be a factor of fluctuation. Under such circumstances, in recent years steelmaking technology has been improved and sol. The variation range of Al can be made extremely small, and the above-described technique is practically no longer used.
[0007]
However, as described above, the addition of an annealing separator containing Sn, and further sol. Even if a large variation in Al is solved by steelmaking technology, secondary recrystallization may not be performed ideally due to the precipitation behavior of AlN, and the magnetic properties cannot always be completely stabilized. I can't say. Also, the film properties may not be sufficient.
[0008]
[Problems to be solved by the invention]
The present invention has been made in order to solve the above-described problems of the prior art in the production technology of grain-oriented electrical steel sheets. and to provide a component adjustment process of annealing separator in the production of steel.
[0009]
[Means for solving problems]
The present inventors investigated in detail the secondary recrystallization behavior of grain-oriented electrical steel sheets using AlN as an inhibitor, and the precipitation rate of AlN was sol. It has been found that Al is rate-limiting and that there are two types of secondary recrystallization failure depending on the inhibitor behavior, both of which are caused by the precipitation behavior of AlN. That is, excessive sol. When there is too much Al, AlN tends to coarsen and the function as an inhibitor is lowered, the suppression of the growth of primary recrystallized grains becomes insufficient, a normal secondary recrystallized structure cannot be produced, and the fine structure and On the other hand, excessive sol. It has been found that when Al is too small, AlN is easily refined and the function as an inhibitor becomes too strong, resulting in a secondary recrystallized structure having a poor orientation, and the magnetic flux density is remarkably deteriorated.
[0010]
In such a case, sol. The amount of Al and N is reduced as much as possible in the component adjustment stage in steelmaking, and SnO ₂ is added to MgO before finish annealing, and the amount is sol. The inventors have found that secondary recrystallization can be stably performed by controlling according to the ratio of the amount of Al and N, and the present proposal has been achieved.
[0011]
That is, the present invention is sol. Hot rolling and cold rolling are performed on a slab for grain-oriented electrical steel sheets containing Al: 0.02% or more and 0.03% or less and N: 0.0065% or more and 0.0095% or less as an inhibitor. An annealing separator for grain-oriented electrical steel sheets used for final finishing annealing by applying an annealing separator mainly composed of MgO to a cold-rolled sheet finished to the final thickness and decarburized and annealed. a component adjustment method, MgO ratio by weight: L00 parts per contain a SnO ₂ within range of 10 parts or more 1 part, sol based on the sol Al and N contents.. The ratio Al / N of Al / N is calculated, and the annealing separator component is adjusted so that the content of SnO ₂ in the annealing separator decreases as the Al / N value increases. It is a component adjustment method of the annealing separator for grain-oriented electrical steel sheets .
[ 0012 ]
In the present invention, the annealing separator may further contain a metal selected from one or two of Ti or Sr or a compound thereof.
[ 0013 ]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail together with the experimental results on which the invention is based. In the present invention, sol. Al is contained in the range of 0.02% or more and 0.03% or less, and SnO ₂ must be added to the annealing separator, which is derived from the results of Experiment 1 shown below. It is.
[ 0014 ]
(Experiment 1)
As shown in Table 1, sol. A series of steels with different Al composition was vacuum-melted in the laboratory, heated at 1350 ° C for 30 minutes, hot-rolled, finished to a sheet thickness of 2.2 mm, and sandwiched by intermediate annealing at 1000 ° C twice. A combination of cold rolling and warm rolling finished to 0.22 mm. Thereafter, decarburization annealing was performed in wet hydrogen at 850 ° C. for 2 minutes, and an annealing separator containing MgO as a main component was applied to perform final finish annealing.
[ 0015 ]
[Table 1]

[ 0016 ]
In this case, the annealing separating agent is a case of adding and when 5 parts by weight was continuously added SnO ₂ relative MgO100 parts, the heating process performed at a heating rate of 10 ° C. / h Upon performing final finish annealing, H ₂ And N ₂ mixed atmosphere only (Condition 1), and N ₂ only up to 800 ° C. and then switching to H ₂ and N ₂ mixed atmosphere (Condition 2). After reaching 1180 ° C., purification annealing was performed in H ₂ for 5 hours. Table 2 shows the magnetic properties and film properties obtained under these conditions.
[ 0017 ]
From the result of Experiment 1, 0.02 ≦ sol. It has been found that when SnO ₂ is added to an annealing separator mainly composed of MgO in the range of Al (%) ≦ 0.03, good magnetic properties can be obtained. When the secondary recrystallized structure was observed, sol. The Al less A steel secondary recrystallization has been performed, due to the low degree of integration of the Goss orientation, the value of the magnetic flux density B ₈ is low. On the other hand, sol. The E steel with a large amount of Al did not undergo secondary recrystallization and had a fine structure. Therefore, sol. The amount of Al needs to be 0.02% or more and 0.03% or less.
[ 0018 ]
[Table 2]

[ 0019 ]
From the above experiments, also coating properties by the addition of SnO ₂ it is also found to always be improved. The case, halfway annealing atmosphere, until this case 800 ° C., when the N ₂ atmosphere, it was found that further magnetic properties is improved. This is because you make in N ₂ atmosphere until 800 ° C. In the final annealing process, can delay the decomposition of SnO _2, after H ₂ introduction decomposed Sn or O is considered to be because the act effectively.
[ 0020 ]
[Experiment 2]
As shown in Table 3, sol. While maintaining the Al at a substantially constant level, the amount of N was changed and the composition steel was vacuum-melted in the laboratory, heated at 1350 ° C. for 30 minutes, hot-rolled, finished to a thickness of 2.2 mm, 1000 ° C. After hot-rolled sheet annealing, pickling was performed, and a combination of two cold rolling and warm rolling sandwiching the intermediate annealing at 1100 ° C. was finished to 0.22 mm. Thereafter, decarburization annealing was performed in wet hydrogen at 850 ° C. for 2 minutes, and an annealing separator containing MgO as a main component was applied to perform final finish annealing.
[ 0021 ]
[Table 3]

[ 0022 ]
In this case, the annealing separator used was 0.5 to 15 parts by weight of SnO ₂ added to 100 parts by weight of MgO, the heating rate of final annealing was 10 ° C./h, the atmosphere was N ₂ up to 850 ° C., and then H _2, and a mixed atmosphere of _{N 2,} purification annealing was subjected 5h at 1180 ° C. in _{H 2.} Table 4 shows the magnetic characteristics and film characteristics at this time.
[ 0023 ]
[Table 4]

[ 0024 ]
From the result of Experiment 2, when 1 to 10 parts by weight of SnO ₂ is added to 100 parts by weight of MgO in the range of 0.0065 ≦ N (%) ≦ 0.0095, good magnetic properties can be obtained. I understood it. With respect to the coating properties, when the addition amount was less than 1 part by weight, the peel resistance was deteriorated, and when it was more than 10 parts by weight, a point-like defect was generated and the peel resistance was significantly deteriorated. When the secondary recrystallized structure was observed, the F steel with less N showed a fine structure without secondary recrystallization. On the other hand, J steel with a lot of N was secondary recrystallized, but its orientation was bad and the magnetic flux density was low.
[ 0025 ]
Here, when considered together with the previous experiment 1, sol. Even within the preferable range of Al and N, the form of secondary recrystallization failure differs depending on the ratio, and there is an optimum value for the amount of SnO ₂ added in MgO. It has been found that it is necessary to decrease the amount of SnO ₂ added as / N increases.
[ 0026 ]
[ Experiment 3 ]
As shown in Table 5, sol. Steel having a composition satisfying the proper range of the present invention for Al and N is vacuum-melted in a laboratory, heated at 1350 ° C. for 30 minutes, hot-rolled, finished to a thickness of 2.2 mm, and hot-rolled at 1000 ° C. After annealing, pickling was performed to finish 0.22 mm by combining two cold rolling and warm rolling sandwiching the intermediate annealing at 1100 ° C. Thereafter, decarburization annealing was performed in wet hydrogen at 850 ° C. for 2 minutes, and an annealing separator containing MgO as a main component was applied to perform final finish annealing. [ 0027 ]
In this case, MgO and SnO ₂ 3 parts by weight was added with respect MgO100 parts during the annealing separator consisting mainly, the final annealing and gradual heating of the 5 ° C. / h up to 700 to 900 ° C., N partway ₂ and then a mixed atmosphere of H ₂ and N ₂ , and after reaching 1180 ° C., the temperature was switched to H ₂ and purification annealing was performed at that temperature for 5 hours. Table 6 shows the magnetic characteristics and film characteristics at this time.
[ 0028 ]
[Table 5]

[ 0029 ]
[Table 6]

[ 0030 ]
From the results of Experiment 3, it was found that the effect of adding SnO ₂ can be obtained even when AlN and a known inhibitor element are used in combination. That is, it was confirmed that even when SnO ₂ is added to the annealing separator, it can be used in combination with AlN such as Se, S, Cu, Sb, Bi. Further, in this experiment, it is a N ₂ atmosphere annealing atmosphere until 750 ° C., and that the grain size of the forsterite film by switching to N _{2 +} H ₂ mixed atmosphere is decreased up to 900 ° C. was observed. It is presumed that the improvement in peel resistance was caused by the finer grain size of the forsterite film, and it was considered that good magnetic properties were obtained accordingly.
[ 0031 ]
When the switching temperature is too low, SnO ₂ is reduced and decomposed by H ₂ , and the effect is lost because the decomposed Sn or O is consumed by the moisture brought in by MgO before acting effectively on the film formation. on the other hand, coating improving effect by the decomposition is delayed SnO ₂ addition of the switching temperature is too high SnO ₂ is considered will not occur. Therefore, the switching temperature is important and should be approximately in the following range.
Switching from N ₂ atmosphere to a mixed atmosphere of _{N 2} and _{H 2:} 750 ° C. or higher, switching from a mixed atmosphere of 850 ° C. or less _{N 2} and _{H 2} to an _{H 2} atmosphere: 1000 ° C. or higher, 1100 ° C. or less [0032]
As shown in the above experimental results, when the amount of SnO ₂ added is decreased as Al / N increases, the product magnetic characteristics are stably improved. The cause of this is as follows. I am thinking. That is, SnO ₂ added to MgO is decomposed into Sn and O by H ₂ during the final annealing, but Sn has a relatively low melting point, so it improves the wettability of the MgO interface and is generated on the steel plate surface by decarburization annealing. The solid-phase reaction between the subscale and MgO is promoted, and the frequency of nucleation of forsterite is increased, thereby improving the coating properties. At this time, when SnO ₂ is large increases also the release of O, atmospheric pressure coil layer becomes high. Therefore, if the amount of SnO ₂ is decreased as Al / N increases, it is presumed that the amount of absorbed N into the steel can be increased, and thereby the function of the inhibitor can be optimized. In other words, for a dispersion system having a large Al / N and a relatively coarse AlN, the amount of absorbed N is increased and the fine AlN is increased, while the Al / N is small and the fine dispersion of AlN is small. It is thought that the amount of fine AlN could be suppressed by reducing the amount of absorbed N.
[ 0033 ]
A typical composition range as the grain-oriented electrical steel sheet material of the present invention is as follows.
C: 0.03% or more and 0.10% or less:
C is an element useful not only for uniform refinement of a hot-rolled structure and a cold-rolled structure but also for the development of Goss orientation, and at least 0.03% is necessary. However, if it exceeds 0.10%, not only decarburization in the subsequent process becomes difficult, but also the Goth orientation is dispersed, so the upper limit is made 0.10%.
[ 0034 ]
Si: 2.5% or more, 4.5% or less:
Si increases the specific resistance of the steel sheet and contributes to the reduction of iron loss. However, if it exceeds 4.5%, the cold rolling property is remarkably impaired, so 4.5% is made the upper limit. On the other hand, if less than 2.5%, not only the specific resistance is lowered, but also the crystal orientation is randomized by α-γ transformation during final finish annealing, and the magnetic properties are impaired, so 2.5% is made the lower limit.
[ 0035 ]
Mn: 0.02% or more, 0.12% or less:
Mn needs at least 0.02% in order to prevent hot brittleness, but if it is too much, MnSe and MnS fine dispersion will be hindered and the magnetic properties will be deteriorated, so the upper limit is made 0.12%. .
[ 0036 ]
At least one selected from Se and S: 0.01% or more and 0.04% or less:
Se and S are effective elements that suppress secondary recrystallization of directional silicon steel. From the viewpoint of inhibiting power, at least 0.01% is necessary, but if it exceeds 0.04%, it is difficult to control fine precipitation, so these values are set as upper and lower limits, respectively.
[ 0037 ]
Inhibitor component: sol. Al: 0.02% or more, 0.03% or less, N: 0.0065% or more, 0.0095% or less:
The range of Al and N was also set to the above range in order to obtain a good secondary recrystallized structure as described above. As the inhibitor, in addition to AlN, one or two selected from MnSe and MnS can be used in combination. Furthermore, in addition to Mn, Se , S, Al, and N described above, Cu, Sn, Sb, Bi, and the like also act advantageously, so they can be contained together. The preferred ranges of these components are Cu, Sn: 0.05% or more and 0.25% or less, Sb, Bi: 0.01% or more, 0.05% or less, respectively. The above addition is possible.
[ 0038 ]
In the present invention, the annealing separator is composed mainly of MgO and SnO ₂ added thereto. However, adding a small amount of known Ti or Sr compound to MgO depending on the purpose is effective for the present invention. This is preferable because it does not impair the effect, but rather produces a complementary effect.
[ 0039 ]
【Example】
[Example 1]
P steel and Q steel having the following composition were melted, made into slabs, soaked at 1420 ° C, finished to 2.2 mm thickness, hot-rolled sheet annealed at 1000 ° C, pickled, and cooled for the first time. After rolling, intermediate annealing was performed at 1100 ° C., and finished to 0.22 mm by the second rolling including warm rolling at 200 ° C. Further, for the purpose of magnetic domain subdivision, grooves having a diameter of 20 μm were introduced at a pitch of 5 mm in the width direction by an etching method. Thereafter subjected to decarburization annealing at 850 ° C., the SnO ₂ 0 parts by weight to MgO100 parts, at each level of 2.6 parts by weight, further 8 parts by weight of TiO _2, 3 weight Sr _{(OH) 2} An annealing separator formed by adding a part is applied, heated to 830 ° C. in a N ₂ atmosphere, and then in a mixed atmosphere of N ₂ and H ₂ at a rate of 10 ° C./h. After reaching 1180 ° C., purify in H ₂ for 5 h. Annealed. Table 7 shows the results of magnetic properties and film properties at this time.
[ 0040 ]
[P steel]
C: 0.070%, Si: 3.32%, Mn: 0.071%,
Se: 0.018%, sol. Al: 0.023%, N: 0.0085%,
Al / N: 2.71, Sb: 0.026%, Cu: 0.11%
[Q steel]
C: 0.072%, Si: 3.25%, Mn: 0.068%,
Se: 0.047%, sol. Al: 0.026%, N: 0.0080 %,
Al / N: 3.25, Sb: 0.027%, Cu: 0.12%
[ 0041 ]
[Table 7]

[ 0042 ]
The latter when comparing P steel and Q steel Al / N ratio is greater. Therefore, in the case of P steel, it was possible to obtain high magnetic properties in any case by increasing the amount of SnO ₂ added to the annealing separator compared to the case of Q steel .
[ 0043 ]
[Example 2]
R steel and S steel having the following composition were melted to form a slab, soaked at 1420 ° C. for 30 minutes, finished to 2.5 mm thickness, hot-rolled sheet annealed at 1150 ° C., pickled, and 200 ° C. It was finished to 0.29 mm by one rolling including warm rolling. Thereafter subjected to decarburization annealing at 850 ° C., the SnO ₂ 0 parts by weight to MgO100 parts, at each level of 3.8 parts by weight, further 10 parts by weight of TiO _2, 3 weight Sr _{(OH) 2} An annealing separator formed by adding a part is applied, heated to 10 ° C./h in a N ₂ atmosphere up to 820 ° C., and then in a mixed atmosphere of N ₂ and H ₂ , and after 1180 ° C., 5 hours of purification annealing in H _{2 is} performed. gave. Table 8 shows the results of magnetic characteristics and film characteristics at this time.
[ 0044 ]
[R steel]
C: 0.073%, Si: 3.27%, Mn: 0.065%,
Se: 0.018%, sol. Al: 0.023%, N: 0.0088%,
Al / N: 2.61, Sb: 0.038%, Cu: 0.07%
[S steel]
C: 0.068%, Si: 3.24%, Mn: 0.068%,
Se: 0.017%, sol. Al: 0.026%, N: 0.0074%, Al / N: 3.51, Sb: 0.042%, Cu: 0.08%
[ 0045 ]
[Table 8]

[ 0046 ]
As in Example 1, by changing the amount of SnO ₂ added to the annealing separator based on the difference in Al / N ratio between R steel and S steel, it always has high magnetic properties and is evaluated by bending peelability. It was possible to obtain an electrical steel sheet having the coating properties.
[ 0047 ]
【The invention's effect】
Since the present invention is configured as described above , the characteristic value may be extremely stable in spite of fluctuations in the Al / N ratio during the production of the grain-oriented electrical steel sheet using AlN as an inhibitor. It is possible to produce a magnetic steel sheet having high magnetic properties at a high yield. Also, the film properties are improved, thereby further improving the magnetic properties.

Claims (2)

In weight ratio, sol. Hot rolling and cold rolling are performed on a slab for grain-oriented electrical steel sheets containing Al: 0.02% or more and 0.03% or less and N: 0.0065% or more and 0.0095% or less as an inhibitor. An annealing separator for grain-oriented electrical steel sheets used for final finishing annealing by applying an annealing separator mainly composed of MgO to a cold-rolled sheet finished to the final thickness and decarburized and annealed. An ingredient adjustment method,
  SnO to MgO: 100 parts by weight ₂ In the range of 1 part or more and 10 parts or less, and the sol. Based on the Al and N contents, sol. The Al / N ratio Al / N value is calculated, and SnO in the annealing separator increases as the Al / N value increases. ₂ The component adjustment method of the annealing separator for grain-oriented electrical steel sheets, wherein the annealing separator component is adjusted so that the content of the steel is reduced. The component adjusting method for an annealing separator for grain-oriented electrical steel sheets according to claim 1, wherein the annealing separator further contains a metal selected from one or two of Ti or Sr or a compound thereof .