JP2012087354A - Finish annealing method of grain oriented magnetic steel sheet, and finish annealing facility - Google Patents

Finish annealing method of grain oriented magnetic steel sheet, and finish annealing facility Download PDF

Info

Publication number
JP2012087354A
JP2012087354A JP2010234226A JP2010234226A JP2012087354A JP 2012087354 A JP2012087354 A JP 2012087354A JP 2010234226 A JP2010234226 A JP 2010234226A JP 2010234226 A JP2010234226 A JP 2010234226A JP 2012087354 A JP2012087354 A JP 2012087354A
Authority
JP
Japan
Prior art keywords
coil
annealing
steel sheet
heating
section
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.)
Granted
Application number
JP2010234226A
Other languages
Japanese (ja)
Other versions
JP5896097B2 (en
Inventor
Yoshimichi Hino
善道 日野
Katsuhiro Takebayashi
克浩 竹林
Tomoyuki Okubo
智幸 大久保
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
JFE Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by JFE Steel Corp filed Critical JFE Steel Corp
Priority to JP2010234226A priority Critical patent/JP5896097B2/en
Publication of JP2012087354A publication Critical patent/JP2012087354A/en
Application granted granted Critical
Publication of JP5896097B2 publication Critical patent/JP5896097B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Abstract

PROBLEM TO BE SOLVED: To provide a finish annealing method of a grain oriented magnetic steel sheet for establishing all of improving the coating characteristic in the finish annealing, suppressing the deterioration of an inhibitor, and shortening the annealing time, and to provide a finish annealing facility thereof.SOLUTION: The finish annealing method of the grain oriented magnetic steel sheet includes applying primary re-crystallization annealing serving as decarburization to a steel sheet after cold rolling, then applying an annealing separating agent mainly made of MgO to the steel sheet surface, drying the agent, winding the sheet on a coil, heating the coil to a predetermined temperature in a furnace while rewinding the coil, winding the sheet on the coil again in the furnace and soaking and holding it for a certain time, then cooling the soaked and held coil while rewinding it, and winding the sheet on the coil again outside the furnace.

Description

本発明は、方向性電磁鋼板の仕上焼鈍方法とその仕上焼鈍設備に関し、特に珪素を主たる合金元素とした鋼から、熱間圧延、冷間圧延および熱処理を最適な条件で組み合わせることによって結晶方位をＧｏｓｓ方位に高度に揃えた方向性電磁鋼板の製造に用いて好適な仕上焼鈍方法と仕上焼鈍設備に関するものである。   The present invention relates to a method of finish annealing of grain-oriented electrical steel sheet and its finish annealing equipment, and in particular, from steel with silicon as the main alloy element, by combining hot rolling, cold rolling and heat treatment under optimum conditions. The present invention relates to a finish annealing method and finish annealing equipment suitable for use in the manufacture of grain-oriented electrical steel sheets that are highly aligned in the Goss orientation.

方向性電磁鋼板は、冷間圧延後、一次再結晶焼鈍を施した鋼板の表面にＭｇＯを主体とするスラリー状の焼鈍分離剤を塗布・乾燥した後、鋼板表面にフォルステライト被膜を形成させて絶縁性を付与すると同時に、二次再結晶を起こさせて電磁特性に優れたＧｏｓｓ方位を有する結晶を優先的に成長させる二次再結晶焼鈍を施し、さらに、１１００℃以上の高温で熱処理して鋼中の不要な元素を取り除く純化焼鈍を施すことで製造されるのが一般的である。上記二次再結晶焼鈍と純化焼鈍を含めた熱処理は、一般に、「仕上焼鈍」あるいは「最終仕上焼鈍」と称されている（以降、「仕上焼鈍」という。）。   The grain-oriented electrical steel sheet is formed by applying and drying a slurry-like annealing separator mainly composed of MgO on the surface of the steel sheet subjected to primary recrystallization annealing after cold rolling, and then forming a forsterite film on the steel sheet surface. At the same time as providing insulating properties, secondary recrystallization annealing is performed to cause secondary recrystallization to preferentially grow crystals having Goss orientation with excellent electromagnetic characteristics, and further, heat treatment is performed at a high temperature of 1100 ° C. or higher. In general, it is manufactured by performing a purification annealing for removing unnecessary elements in steel. The heat treatment including the secondary recrystallization annealing and the purification annealing is generally referred to as “finish annealing” or “final annealing” (hereinafter referred to as “finish annealing”).

ここで、上記仕上焼鈍は、従来、コイル状に巻かれた鋼板（以下「コイル」と称する。）を、雰囲気を制御したインナーカバー内に載置し、バッチ式の箱型焼鈍炉を用いて行われているが、このようなコイル状態で行う熱処理は、基本的に鉄の塊を外部から加熱する方法であるため、熱がコイル内部に伝わり難く、コイル表面と内部との温度差が大きくなって温度分布が不均一となるだけでなく、コイル内部が所望の温度に上昇するのに長時間を要するため、生産性が低いという問題がある。   Here, the finish annealing is conventionally performed by placing a coiled steel sheet (hereinafter referred to as “coil”) in an inner cover with controlled atmosphere and using a batch type box annealing furnace. Although heat treatment performed in such a coil state is basically a method of heating an iron lump from the outside, it is difficult for heat to be transferred to the inside of the coil, and the temperature difference between the coil surface and the inside is large. As a result, not only the temperature distribution becomes non-uniform, but also it takes a long time for the inside of the coil to rise to a desired temperature, resulting in low productivity.

また、フォルステライト皮膜を形成させるために鋼板表面に塗布された焼鈍分離剤は、ＭｇＯの一部が水和反応を起こして水酸化マグネシウム（Ｍｇ（ＯＨ）２）に変化している。このＭｇ（ＯＨ）２は、焼鈍分離剤塗布後の乾燥では脱水されないため、結晶水の形で残存し、巻き取られたコイルの鋼板間に持ち込まれ、仕上焼鈍の加熱時（温度が３５０℃近傍）に水分を放出することになる。この水分は、酸化性であり、コイルに巻き取られた鋼板間という狭い空間を通って徐々に放出され、しかも、コイル内の昇温速度の違いによって長時間に亘って水分が放出され続けるため、温度の上昇速度が大きく、既にフォルステライト皮膜が形成されているコイル外縁部近傍におけるフォルステライト皮膜の特性を著しく劣化させるという問題がある。 In addition, in the annealing separator applied to the steel sheet surface to form a forsterite film, a part of MgO undergoes a hydration reaction and changes to magnesium hydroxide (Mg (OH) 2 ). Since this Mg (OH) 2 is not dehydrated by drying after the application of the annealing separator, it remains in the form of crystal water and is brought between the steel plates of the coil that has been wound up. Water will be released in the vicinity). This moisture is oxidative and is gradually released through a narrow space between the steel sheets wound around the coil, and the moisture continues to be released over a long period of time due to the difference in temperature rise rate in the coil. There is a problem that the temperature rise rate is large and the characteristics of the forsterite film in the vicinity of the outer edge of the coil where the forsterite film has already been formed are significantly deteriorated.

上記問題に対応する技術としては、例えば、特許文献１には、焼鈍分離剤を塗布したコイルを、常温から６００℃までを鋼板自体を通電加熱あるいは誘導加熱で直接発熱させる方法で加熱し、その後、６００℃超から高温の保持温度まで、従来の間接加熱法で加熱する仕上焼鈍方法が開示されている。
また、特許文献２には、コイル状の金属をバッチ焼鈍するにあたり、コイルを巻きほどきながら通電加熱装置あるいは誘導加熱装置で所定の温度に加熱し、再度コイル状に巻いた後、直ちにバッチ焼鈍することで、コイル状に巻いた金属を、効率よくかつ均一に加熱するコイル加熱方法を開示されている。 As a technique for dealing with the above problem, for example, in Patent Document 1, a coil coated with an annealing separator is heated from room temperature to 600 ° C. by a method in which the steel sheet itself is directly heated by electric heating or induction heating, and thereafter A finish annealing method is disclosed in which heating is performed by a conventional indirect heating method from a temperature exceeding 600 ° C. to a high holding temperature.
Further, in Patent Document 2, in batch annealing of a coiled metal, a coil annealing is performed by heating the coiled metal to a predetermined temperature with an electric heating device or an induction heating device, winding the coil again, and then immediately performing batch annealing. Thus, a coil heating method has been disclosed in which a metal wound in a coil shape is efficiently and uniformly heated.

また、二次再結晶を起こさせるため鋼中に添加されているインヒビター（ＡｌＮ）の強度は、一般に強いほど好ましいが、鋼中の酸可溶性のＡｌ量やＮ量に大きく依存する。しかし、酸可溶性のＡｌ量は、加熱速度が遅い従来の箱型焼鈍では、加熱時に酸化されて減少するため、インヒビター強度の劣化を免れないという問題がある。   In general, the strength of the inhibitor (AlN) added to the steel to cause secondary recrystallization is preferably as high as possible, but greatly depends on the amount of acid-soluble Al and N in the steel. However, since the amount of acid-soluble Al is reduced by oxidation during heating in the conventional box-type annealing with a slow heating rate, there is a problem in that deterioration of the inhibitor strength cannot be avoided.

この問題に対応する技術としては、例えば、特許文献３等には、低温部と高温部からなる炉構造で、それぞれに巻き取りリールを有する仕上焼鈍炉の低温部に鋼帯コイルを入れ、９２０℃以上１１５０℃以下に保持した高温部のリールに鋼帯の昇温速度が５０℃／ｈｒ以上となるように加熱しながら巻き取り、５時間以上保持する方向性珪素鋼帯の製造方法が開示されている。   As a technique for dealing with this problem, for example, Patent Document 3 discloses a furnace structure composed of a low temperature part and a high temperature part, and a steel strip coil is placed in the low temperature part of a finish annealing furnace each having a take-up reel. Disclosed is a method for producing a directional silicon steel strip that is wound on a reel in a high-temperature section held at a temperature of not lower than 1 ° C. and not higher than 1150 ° C. while being heated so that the temperature rising rate of the steel strip is 50 ° C./hr or higher Has been.

特許第４３３５９８２号公報Japanese Patent No. 43355982 特開平１１−２６９５５９号公報JP-A-11-269559 特許第２６８９１９３号公報Japanese Patent No. 2689193

しかしながら、上記特許文献１や２の技術は、６００℃程度までは短時間で昇温することができるが、その後は、通常の間接加熱で加熱する方法であるため、被膜特性は改善されるものの、依然として、焼鈍温度の不均一性や焼鈍時間が長いという問題が残ることになる。
また、特許文献３の技術は、仕上焼鈍を低温部と高温部からなる炉構造の仕上焼鈍炉内で行い、６５０℃から９５０℃までの昇温速度を高めることでインヒビターの劣化を抑制しているが、６５０℃までの加熱はコイル状態のままで行っているため、被膜特性を改善することはできず、焼鈍時間の短縮も十分に図れないという問題がある。 However, although the techniques of Patent Documents 1 and 2 can raise the temperature in a short time up to about 600 ° C., after that, since the method is a method of heating by normal indirect heating, the film characteristics are improved. Still, the problem that the annealing temperature is uneven and the annealing time is long remains.
Moreover, the technique of patent document 3 suppresses deterioration of an inhibitor by performing finish annealing in the finish annealing furnace of the furnace structure which consists of a low temperature part and a high temperature part, and raising the temperature increase rate from 650 degreeC to 950 degreeC. However, since heating up to 650 ° C. is performed in a coil state, there is a problem that the film characteristics cannot be improved and the annealing time cannot be sufficiently shortened.

本発明は、従来技術が抱える上記問題点に鑑みてなされたものであり、その目的は、従来技術における仕上焼鈍方法を抜本的に見直すことで、被膜特性の改善、インヒビターの劣化抑制および焼鈍時間の短縮の全てを満たす方向性電磁鋼板の仕上焼鈍方法を提案するとともに、その仕上焼鈍設備を提供することにある。   The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to drastically review the finish annealing method in the prior art, thereby improving the film properties, inhibiting the deterioration of the inhibitor, and annealing time. In addition to proposing a finish annealing method for grain-oriented electrical steel sheets that satisfies all of the above shortening, it is intended to provide the finish annealing equipment.

発明者らは、上記問題点を解決するべく鋭意検討を重ねた。その結果、仕上焼鈍における鋼板の加熱を、コイル状態ではなく、コイルを巻き戻しつつ鋼板の状態で行い、所定の温度に昇温後、炉内でコイルに巻き取って一定時間均熱保持し、その後、好ましくは、そのコイルを巻き戻しつつ鋼板の状態で所定の温度まで冷却し、コイルに巻き取るようにすれば、加熱・冷却に要する時間を大幅に削減できると共に、被膜特性の劣化やインヒビターの劣化を防止することが可能となることに想到し、本発明を開発するに至った。   The inventors have intensively studied to solve the above problems. As a result, the heating of the steel plate in the finish annealing is performed in the state of the steel plate while rewinding the coil, not in the coil state, after raising the temperature to a predetermined temperature, it is wound around the coil in a furnace and kept soaked for a certain period of time, After that, preferably, if the coil is rewound and cooled to a predetermined temperature in the state of a steel sheet and wound around the coil, the time required for heating and cooling can be greatly reduced, and the coating properties are deteriorated and the inhibitor is reduced. As a result, the present invention has been developed.

すなわち、本発明は、冷間圧延後の鋼板に脱炭を兼ねた一次再結晶焼鈍を施してから、鋼板表面にＭｇＯを主体とする焼鈍分離剤を塗布、乾燥し、コイルに巻き取った後、このコイルを巻き戻しながら炉中で所定温度に加熱し、炉中で再度コイルに巻き取って一定時間均熱保持する方向性電磁鋼板の仕上焼鈍方法である。   That is, the present invention is a method in which a steel sheet after cold rolling is subjected to primary recrystallization annealing that also serves as decarburization, and then an annealing separator mainly composed of MgO is applied to the steel sheet surface, dried, and wound on a coil. This is a finish annealing method for grain-oriented electrical steel sheets that is heated to a predetermined temperature in a furnace while the coil is rewound, wound again in the furnace in the furnace, and soaked for a certain period of time.

本発明の仕上焼鈍方法における上記所定温度は、二次再結晶温度以上の温度であることを特徴とする。   The predetermined temperature in the finish annealing method of the present invention is a temperature that is equal to or higher than the secondary recrystallization temperature.

また、本発明の仕上焼鈍方法は、上記均熱処理後、さらに、純化焼鈍温度まで加熱し、一定時間均熱保持することを特徴とする。   Further, the finish annealing method of the present invention is characterized in that after the above-mentioned soaking process, heating is further performed to a purification annealing temperature and soaking is maintained for a certain time.

また、本発明の仕上焼鈍方法は、上記均熱保持したコイルを巻き戻しつつ冷却し、再度、炉外でコイルに巻き取ること特徴とする。   In addition, the finish annealing method of the present invention is characterized in that the coil that has been kept soaked is cooled while being rewound and is wound around the coil again outside the furnace.

また、本発明は、一次再結晶焼鈍後、鋼板表面にＭｇＯを主体とする焼鈍分離剤を塗布、乾燥した鋼板のコイルを巻き戻す巻き戻しセクションと、上記巻き戻した鋼板を所定温度まで加熱する加熱セクションと、上記加熱後の鋼板を炉内で再びコイルに巻き取って均熱保持する均熱セクションとを有する方向性電磁鋼板の仕上焼鈍設備である。   In addition, the present invention, after primary recrystallization annealing, an annealing separator mainly composed of MgO is applied to the surface of the steel sheet, a rewinding section for rewinding the coil of the dried steel sheet, and heating the rewinded steel sheet to a predetermined temperature. This is a finish annealing facility for grain-oriented electrical steel sheets having a heating section and a soaking section that winds the steel plate after heating to a coil again in a furnace and keeps it soaked.

本発明の仕上焼鈍設備における上記均熱セクションは、純化焼鈍温度まで加熱し、均熱保持する機能を有するものであることを特徴とする。   The soaking section in the finish annealing equipment of the present invention has a function of heating to the purification annealing temperature and maintaining soaking.

また、本発明の仕上焼鈍設備は、上記均熱セクションが巻き取ったコイルを巻き戻す機能を有するとともに、巻き戻した鋼板を冷却する冷却セクションと、上記冷却後の鋼板を巻き取る巻き取りセクションを有することを特徴とする。   Further, the finish annealing equipment of the present invention has a function of rewinding the coil wound by the soaking section, a cooling section for cooling the unwound steel sheet, and a winding section for winding the steel sheet after cooling. It is characterized by having.

また、本発明の仕上焼鈍設備は、上記加熱セクションが、冷却セクションを兼ねることを特徴とする。   In the finish annealing equipment of the present invention, the heating section also serves as a cooling section.

また、本発明の仕上焼鈍設備は、上記巻き戻しセクションが、巻き取りセクションを兼ねることを特徴とする。   In the finish annealing equipment of the present invention, the rewinding section also serves as a winding section.

本発明によれば、仕上焼鈍における鋼板の加熱を、コイルを巻き戻しつつ鋼板（ストリップ）の状態で行い、所定の温度に昇温後、コイルに巻き取って一定時間均熱保持し、その後、コイルを巻き戻しつつ鋼帯の状態で所定の温度に冷却するので、加熱・冷却に要する時間を大幅に短縮できると共に、被膜特性の劣化やインヒビターの劣化を防止することが可能となる。したがって、本発明によれば、被膜特性および磁気特性に優れる方向性電磁鋼板を生産性良く製造することが可能となる。   According to the present invention, the heating of the steel plate in the finish annealing is performed in the state of the steel plate (strip) while rewinding the coil, and after raising the temperature to a predetermined temperature, the coil is wound up and kept soaked for a certain time, Since the steel strip is cooled to a predetermined temperature while the coil is rewound, the time required for heating and cooling can be greatly shortened, and the deterioration of the film characteristics and the deterioration of the inhibitor can be prevented. Therefore, according to the present invention, a grain-oriented electrical steel sheet having excellent film characteristics and magnetic characteristics can be produced with high productivity.

本発明の仕上焼鈍設備の全体を説明する図である。It is a figure explaining the whole finish annealing equipment of the present invention. 本発明の仕上焼鈍設備を用いた仕上焼鈍方法を説明する図であり、（ａ）は加熱段階、（ｂ）は均熱段階、（ｃ）は冷却段階を示す。It is a figure explaining the finish annealing method using the finish annealing equipment of the present invention, (a) shows a heating stage, (b) shows a soaking stage, and (c) shows a cooling stage.

本発明の仕上焼鈍設備について、図１および図２に示した。
図１は、本発明に係る仕上焼鈍設備の全体像を示す模式図である。また、図２は、本発明の仕上焼鈍方法を工程順に説明する図であり、（ａ）はコイルから巻き戻した鋼板を加熱し、コイルに巻き取っている状態を、（ｂ）は、所定の温度に加熱されたコイルが均熱保持されている状態を、（ｃ）は、仕上焼鈍を終えたコイルが再び巻き戻され、冷却後、コイルに巻き取られている状態を示している。以下、図に沿って詳細に説明する。 The finish annealing equipment of the present invention is shown in FIG. 1 and FIG.
FIG. 1 is a schematic view showing an overall image of a finish annealing facility according to the present invention. FIG. 2 is a diagram for explaining the finish annealing method of the present invention in the order of steps, where (a) shows a state where a steel sheet unwound from a coil is heated and wound around the coil, and (b) shows a predetermined state. (C) shows a state where the coil after finishing annealing is rewound again, and is wound around the coil after cooling. Hereinafter, it demonstrates in detail along a figure.

図２（ａ）は、一次再結晶焼鈍後、鋼板表面にＭｇＯを主体とする焼鈍分離剤を塗布・乾燥した後、巻き取られたコイル１が巻き戻され、巻き戻された鋼板がデフレクターロール２によって方向が転向され、溶接機３で炉内の巻き取り装置に既に巻き付けてある図示されていない先導コイル（ダミーコイル）の尾端と接合された後、加熱セクション４に導入され、この中に設置された加熱設備８ａで所定の温度に加熱後、均熱セクション５で再びコイル６に巻き取られ、加熱設備８ｂで所定の温度に均熱保持されつつある状態を示している。   FIG. 2 (a) shows that after primary recrystallization annealing, an annealing separator mainly composed of MgO is applied to the steel sheet surface and dried, and then the wound coil 1 is rewound, and the rewound steel sheet is deflected by a deflector roll. The direction is changed by 2 and joined to the tail end of a lead coil (dummy coil) (not shown) that has already been wound around the winding device in the furnace by the welding machine 3 and then introduced into the heating section 4. After heating to a predetermined temperature by the heating equipment 8a installed in the above, the coil 6 is wound again by the soaking section 5 and is kept soaked at the predetermined temperature by the heating equipment 8b.

ここで、加熱セクション４および均熱セクション５の間には仕切りやシールロール等を設けて、それぞれの雰囲気のガス組成を最適な条件に制御可能となっており、例えば、加熱セクションは、窒素ガス雰囲気、均熱セクションは水素ガス雰囲気に制御することができる。また、いずれのセクションも、外気の侵入を防止するため、外気よりもやや正圧に保持されている。さらに、成膜反応によるガス組成変化を雰囲気ガスの供給によって補正できるだけのガス供給能力を備えていることも必要である。   Here, a partition, a seal roll, or the like is provided between the heating section 4 and the soaking section 5 so that the gas composition of each atmosphere can be controlled to an optimum condition. For example, the heating section includes nitrogen gas. The atmosphere and soaking section can be controlled to a hydrogen gas atmosphere. Each section is held at a slightly higher positive pressure than the outside air in order to prevent the outside air from entering. Furthermore, it is also necessary to have a gas supply capacity that can correct the gas composition change due to the film formation reaction by supplying the atmospheric gas.

また、図２（ａ）中の加熱設備８ａは、コイルを所定の温度、例えば、二次再結晶温度以上の温度まで加熱するためのもの、また、加熱設備８ｂは、コイルを所定の温度、例えば、二次再結晶温度以上の温度に均熱保持するためのものであり、その加熱方式は、誘導加熱方式や通電加熱方式としてもよいが、電熱ヒータやラジアントチューブのような輻射加熱方式としても構わない。また、加熱した雰囲気ガスをセクション内に吹き込む方式を用いてもよい。さらに、上記の方式を組み合わせて用いてもよい。ただし、高速加熱する観点からは、誘導加熱方式や通電加熱方式を用いることが好ましい。   Moreover, the heating equipment 8a in FIG. 2 (a) is for heating the coil to a predetermined temperature, for example, a temperature equal to or higher than the secondary recrystallization temperature, and the heating equipment 8b is a coil having a predetermined temperature, For example, it is for maintaining soaking at a temperature above the secondary recrystallization temperature, and the heating method may be an induction heating method or an electric heating method, but as a radiant heating method such as an electric heater or a radiant tube. It doesn't matter. Further, a method of blowing heated atmospheric gas into the section may be used. Further, a combination of the above methods may be used. However, from the viewpoint of high-speed heating, it is preferable to use an induction heating method or an electric heating method.

図２（ｂ）は、一次再結晶焼鈍後のコイルが、完全に均熱セクション５内に巻き取られて、均熱保持されている状態を示しており、コイルの外周部分には、焼鈍中にコイルはルーズになるのを防止するため、コイル押さえ１０が軽く当接されている。また、炉内のコイル６の外周尾端には、次の工程でコイル６を巻き戻して、巻き取りコイル７とするための先導役を果たすダミー材１１が接合されている。ただし、このダミー材１１は、冷間圧延後のコイル両端に発生する非定常部分で代用してもよく、必須のものではない。   FIG. 2B shows a state in which the coil after the primary recrystallization annealing is completely wound up in the soaking section 5 and kept soaking, and the outer peripheral portion of the coil is being annealed. In order to prevent the coil from becoming loose, the coil retainer 10 is lightly abutted. In addition, a dummy material 11 serving as a leading member for rewinding the coil 6 in the next step to form the take-up coil 7 is joined to the outer peripheral tail end of the coil 6 in the furnace. However, the dummy material 11 may be replaced by unsteady portions generated at both ends of the coil after cold rolling, and is not essential.

なお、この工程は、鋼板を所定の温度以上に加熱後、均熱保持することで健全なフォルステライト被膜を形成させるとともに、二次再結晶焼鈍を完了させることを主目的とするものであるが、その後、さらに昇温し、純化焼鈍を行ってもよく、加熱設備８ｂは、そのための加熱能力を有するものであることが好ましい。なお、加熱方式については、前述した方法が採用でき、特に限定されない。なお、純化焼鈍は、通常、１０５０〜１２５０℃で、１〜２４ｈｒの範囲で行われている。また、純化焼鈍における雰囲気は、水素ガスが多く用いられている。   The main purpose of this step is to form a healthy forsterite film by heating the steel sheet to a predetermined temperature or higher and then maintain a uniform temperature, and to complete secondary recrystallization annealing. Thereafter, the temperature may be further raised and purification annealing may be performed, and the heating equipment 8b preferably has a heating capability for that purpose. In addition, about the heating system, the method mentioned above can be employ | adopted and it does not specifically limit. The purification annealing is usually performed at 1050 to 1250 ° C. in the range of 1 to 24 hours. Further, hydrogen gas is often used for the atmosphere in the purification annealing.

図２（ｃ）は、仕上焼鈍が終了したコイルが、巻き戻され、冷却セクションに設けられた冷却設備９で室温近傍温度（１５０℃程度）まで冷却された後、巻き取りセクションで、コイル７に巻き取られつつある状態を示したものである。なお、本図では、上記冷却セクションは、設備コストの面から、加熱セクションを兼ねているが、エネルギー効率やメンテナンス等の面から、別のセクションとして設けてもよい。また、同様に、本図では、コイルの巻き戻しセクションと巻き取りセクションとを別々に配設した例を示したが、巻き戻しセクションが巻き取りセクションを兼ねたものであってもよい。   FIG. 2 (c) shows that after the finish annealing, the coil is unwound and cooled to a temperature near room temperature (about 150 ° C.) by the cooling equipment 9 provided in the cooling section. It shows the state that is being wound on. In the figure, the cooling section also serves as a heating section from the viewpoint of equipment cost, but may be provided as a separate section from the viewpoint of energy efficiency and maintenance. Similarly, in this drawing, an example in which the coil rewinding section and the winding section are separately provided is shown, but the rewinding section may also serve as the winding section.

ここで、上記冷却設備は、冷却に伴う鋼板表面の酸化や熱歪の発生を防止する観点からは、比較的冷却速度が遅いガス冷却とするのが好ましい。吹き付けるガスとしては、窒素ガスやアルゴンガス等を用いることができる。なお、酸化や熱歪が問題とならない温度領域にミスト冷却や水冷を併用してもよい。   Here, it is preferable that the cooling equipment is gas cooling with a relatively slow cooling rate from the viewpoint of preventing the oxidation of the steel sheet surface and the occurrence of thermal strain accompanying the cooling. Nitrogen gas, argon gas, or the like can be used as the blowing gas. It should be noted that mist cooling or water cooling may be used in combination in a temperature region where oxidation and thermal strain do not matter.

なお、図１，２には、コイル軸が垂直方向を向いたアップエンドの状態でコイルの巻き戻し、巻き取りおよび焼鈍を行う例について示したが、これらをコイル軸が水平方向を向いたダウンエンドの状態で行ってもよい。また、図１，２においては、加熱設備や冷却設備を簡略化してそれぞれ１対ずつ図示したが、必要とされる能力に応じて適宜増やすことができることはもちろんである。   FIGS. 1 and 2 show an example in which the coil is unwound, wound and annealed in an up-end state in which the coil axis is oriented in the vertical direction. You may carry out in the state of an end. In FIGS. 1 and 2, the heating equipment and the cooling equipment are simplified and shown in pairs, but it is needless to say that they can be appropriately increased according to the required capacity.

上記本発明の仕上焼鈍装置によれば、鋼板を巻き戻しながら加熱することができるので、鋼板への伝熱が十分に行われ、コイル状態で加熱する場合よりも、加熱に要する時間を大幅に短縮することが可能となる。例えば、板厚が０．３ｍｍ程度の鋼板であれば、８００℃までを数分で加熱することができる。したがって、従来技術で問題となっていた長時間加熱によるインヒビターの劣化という問題は起こらないので、二次再結晶を安定して発現させることができる。ただし、板厚が０．５ｍｍを超えると、８００℃までの加熱所要時間が１０分程度になるので、加熱セクションが長大となったり、加熱設備が大型化したりして、設備コストが増大するため好ましくない。   According to the finish annealing apparatus of the present invention, since the steel sheet can be heated while being rewound, the heat transfer to the steel sheet is sufficiently performed, and the time required for heating is greatly increased as compared with the case of heating in a coil state. It can be shortened. For example, if the steel plate has a thickness of about 0.3 mm, it can be heated up to 800 ° C. in a few minutes. Therefore, the problem of deterioration of the inhibitor due to long-time heating, which has been a problem in the prior art, does not occur, and secondary recrystallization can be stably expressed. However, if the plate thickness exceeds 0.5 mm, the required heating time up to 800 ° C. is about 10 minutes, so that the heating section becomes longer and the heating equipment becomes larger, increasing the equipment cost. It is not preferable.

同様に、本発明の仕上焼鈍設備によれば、鋼板を巻き戻しながら冷却することができるので、冷却に要する時間を大幅に短縮することができる。その結果、本発明の仕上焼鈍設備では、仕上焼鈍に要する時間が、実質的にフォルステライト被膜形成と二次再結晶に必要な時間あるいはこれに加えて純化に必要な時間のみとなるので、仕上焼鈍時間を大幅に短縮することが可能となる。   Similarly, according to the finish annealing equipment of the present invention, since the steel sheet can be cooled while being rewound, the time required for cooling can be greatly shortened. As a result, in the finish annealing equipment of the present invention, the time required for finish annealing is substantially only the time required for forsterite film formation and secondary recrystallization, or in addition to this, the time required for purification. The annealing time can be greatly shortened.

また、本発明の仕上焼鈍設備は、コイルに巻き取られた鋼板を巻き戻しながら加熱するので、焼鈍分離剤に含まれるＭｇ（ＯＨ）２から放出される水分による悪影響を受けることがない。したがって、被膜特性に優れた製品を安定して得ることができる。 Moreover, since the finish annealing equipment of this invention heats, rewinding the steel plate wound by the coil, it does not receive the bad influence by the water | moisture content discharge | released from Mg (OH) 2 contained in an annealing separator. Therefore, a product having excellent coating properties can be obtained stably.

また、本発明の仕上焼鈍設備によれば、入側に切断、溶接設備が設置されているので、単重が小さなコイルを複数溶接して、大単重のコイルとすることができる。したがって、仕上焼鈍設備の処理能力に合わせて、効率よく熱処理することが可能となる。   Moreover, according to the finish annealing equipment of this invention, since the cutting | disconnection and welding equipment are installed in the entrance side, a plurality of coils with small single weight can be welded, and it can be set as a large single weight coil. Therefore, heat treatment can be efficiently performed according to the processing capacity of the finish annealing equipment.

Ｃ：０．０４ｍａｓｓ％、Ｓｉ：２．９ｍａｓｓ％、Ｍｎ：０．０７ｍａｓｓ％、Ａｌ：０．０１ｍａｓｓ％、Ｎ：０．００７ｍａｓｓ％、Ｓ＋Ｓｅ：０．０２ｍａｓｓ％を含有する冷間圧延後の方向性電磁鋼板用鋼板（板厚：０．３ｍｍ、板幅：１０１０ｍｍ）を、脱炭焼鈍を兼ねた一次再結晶焼鈍後、ＭｇＯを主体とした焼鈍分離剤を鋼板表面に塗布・乾燥してからコイルに巻き取り、単重が１５トンのコイルを１０コイル製作した。
これらのコイルを、従来のバッチ式の仕上焼鈍炉と、本発明の仕上焼鈍設備を用いて５コイルずつ仕上焼鈍し、加熱開始から冷却完了までの所要時間を比較した。 C: direction after cold rolling containing 0.04 mass%, Si: 2.9 mass%, Mn: 0.07 mass%, Al: 0.01 mass%, N: 0.007 mass%, S + Se: 0.02 mass% After the primary recrystallization annealing, which is also used for decarburization annealing, is applied to the steel sheet surface, the MgO-based annealing separator is applied and dried on the steel sheet surface (sheet thickness: 0.3 mm, plate width: 1010 mm). The coil was wound up and 10 coils having a unit weight of 15 tons were manufactured.
These coils were subjected to finish annealing by 5 coils using the conventional batch type finish annealing furnace and the finish annealing equipment of the present invention, and the time required from the start of heating to the completion of cooling was compared.

Figure 2012087354
Figure 2012087354

結果を表１に示した。従来のバッチ式の仕上焼鈍炉での所要時間を１００とした場合、本発明の仕上焼鈍設備では５０となり、従来の方法よりも大幅に時間を短縮することができた。
また、仕上焼鈍後の方向性電磁鋼板の被膜品質を、コイル全長に対する欠陥発生長さを測定して比較したが、本発明の仕上焼鈍設備を用いた場合には、欠陥発生率を１／４に減少することができた。ここで、本発明例の被膜品質が従来例よりも向上した理由は、本発明の仕上焼鈍設備では、加熱中の鋼板の露出面積が大きく、反応や蒸発によって発生した水分や各種化学成分のガス等が炉中に容易に消散するのに対して、従来の仕上焼鈍炉では、反応や蒸発によって発生した水分や各種ガスがコイルに巻かれた鋼板の狭い層間に長時間滞留し、被膜と反応して欠陥を生じるためと考えられる。
なお、本発明の仕上焼鈍設備で製造した方向性電磁鋼板は、磁気特性も、従来方法のものと同等以上であることを確認している。 The results are shown in Table 1. When the time required in the conventional batch-type finish annealing furnace is set to 100, the finish annealing equipment of the present invention is 50, and the time can be significantly shortened compared with the conventional method.
In addition, the coating quality of the grain-oriented electrical steel sheet after finish annealing was compared by measuring the length of occurrence of defects relative to the entire length of the coil. When the finish annealing equipment of the present invention was used, the defect occurrence rate was reduced to 1/4. Could be reduced. Here, the reason why the coating quality of the example of the present invention is improved over that of the conventional example is that, in the finish annealing equipment of the present invention, the exposed area of the steel plate being heated is large, moisture generated by reaction and evaporation, and gases of various chemical components In the conventional finish annealing furnace, moisture and various gases generated by reaction and evaporation stay for a long time between the narrow layers of the steel sheet wound around the coil, and react with the coating. This is considered to cause defects.
In addition, the grain-oriented electrical steel sheet manufactured with the finish annealing equipment of this invention has confirmed that a magnetic characteristic is also equal to or more than the thing of the conventional method.

本発明の技術は、インヒビターを用いた方向性電磁鋼板の製造に用いられる仕上焼鈍設備に限定されるものではなく、例えば、インヒビターレスの方向性電磁鋼板や、二方向性電磁鋼板、無方向性電磁鋼板の仕上焼鈍にも適用することができる。また、本発明の仕上焼鈍設備は、一般冷延鋼板のような汎用の連続焼鈍ラインで製造することが難しい、例えば、極薄の材料や、従来の連続焼鈍設備では対応できないような均一な温度に長時間保持する必要がある材料等、特殊な熱処理が要求される材料の熱処理用としても活用することができる。   The technology of the present invention is not limited to the finish annealing equipment used in the manufacture of grain-oriented electrical steel sheets using inhibitors, for example, inhibitorless grain-oriented electrical steel sheets, bidirectional magnetic steel sheets, non-oriented It can also be applied to finish annealing of electrical steel sheets. In addition, the finish annealing equipment of the present invention is difficult to manufacture in a general-purpose continuous annealing line such as a general cold-rolled steel sheet, for example, an extremely thin material or a uniform temperature that cannot be handled by conventional continuous annealing equipment. It can also be used for heat treatment of materials that require special heat treatment, such as materials that need to be held for a long time.

１：仕上焼鈍前のコイル（一次再結晶焼鈍後コイル）
２：デフレクターロール
３：切断・溶接機
４：加熱・冷却セクション
４ａ：シールロール
５：均熱セクション
６：仕上焼鈍中のコイル
７：仕上焼鈍後のコイル
８ａ，８ｂ：加熱設備（加熱ヒータ）
９：冷却設備（冷却ガス供給設備）
１０：コイル押さえ
１１：ダミー材 1: Coil before final annealing (coil after primary recrystallization annealing)
2: Deflector roll 3: Cutting / welding machine 4: Heating / cooling section 4a: Seal roll 5: Soaking section 6: Coil during finish annealing 7: Coil after finish annealing 8a, 8b: Heating equipment (heater)
9: Cooling equipment (cooling gas supply equipment)
10: Coil retainer 11: Dummy material

Claims (9)

冷間圧延後の鋼板に脱炭を兼ねた一次再結晶焼鈍を施してから、鋼板表面にＭｇＯを主体とする焼鈍分離剤を塗布、乾燥し、コイルに巻き取った後、このコイルを巻き戻しながら炉中で所定温度に加熱し、炉中で再度コイルに巻き取って一定時間均熱保持する方向性電磁鋼板の仕上焼鈍方法。 The steel sheet after cold rolling is subjected to primary recrystallization annealing that also serves as decarburization, and then the steel sheet surface is coated with an annealing separator mainly composed of MgO, dried, wound on a coil, and then rewound. A method of finish annealing a grain-oriented electrical steel sheet that is heated to a predetermined temperature in a furnace, wound around a coil again in the furnace, and kept soaked for a certain period of time. 上記所定温度は、二次再結晶温度以上の温度であることを特徴とする請求項１に記載の仕上焼鈍方法。 The finish annealing method according to claim 1, wherein the predetermined temperature is a temperature equal to or higher than a secondary recrystallization temperature. 上記均熱処理後、さらに、純化焼鈍温度まで加熱し、一定時間均熱保持することを特徴とする請求項１または２に記載の仕上焼鈍方法。 3. The finish annealing method according to claim 1 or 2, wherein after the soaking process, heating is further performed to a purification annealing temperature and soaking is maintained for a certain time. 上記均熱保持したコイルを巻き戻しつつ冷却し、再度、炉外でコイルに巻き取ること特徴とする請求項１〜３のいずれか１項に記載の仕上焼鈍方法。 The finish annealing method according to any one of claims 1 to 3, wherein the coil that has been soaked is cooled while being rewound and then wound around the coil again outside the furnace. 一次再結晶焼鈍後、鋼板表面にＭｇＯを主体とする焼鈍分離剤を塗布、乾燥した鋼板のコイルを巻き戻す巻き戻しセクションと、上記巻き戻した鋼板を所定温度まで加熱する加熱セクションと、上記加熱後の鋼板を炉内で再びコイルに巻き取って均熱保持する均熱セクションとを有する方向性電磁鋼板の仕上焼鈍設備。 After primary recrystallization annealing, an annealing separator mainly composed of MgO is applied to the surface of the steel sheet, a rewinding section for rewinding the coil of the dried steel sheet, a heating section for heating the unwound steel sheet to a predetermined temperature, and the heating Finishing annealing equipment for grain-oriented electrical steel sheets having a soaking section that winds the later steel sheet again in a furnace and winds it around a coil. 上記均熱セクションは、純化焼鈍温度まで加熱し、均熱保持する機能を有するものであることを特徴とする請求項５に記載の仕上焼鈍設備。 6. The finishing annealing apparatus according to claim 5, wherein the soaking section has a function of heating to a purification annealing temperature and maintaining soaking. 上記均熱セクションが巻き取ったコイルを巻き戻す機能を有するとともに、巻き戻した鋼板を冷却する冷却セクションと、上記冷却後の鋼板を巻き取る巻き取りセクションを有することを特徴とする請求項５または６に記載の仕上焼鈍設備。 6. The heat equalizing section has a function of rewinding the wound coil, and has a cooling section for cooling the rewinded steel sheet, and a winding section for winding the cooled steel sheet. 6. Finishing annealing equipment according to 6. 上記加熱セクションが、冷却セクションを兼ねることを特徴とする請求項５〜７のいずれか１項に記載の仕上焼鈍設備。 The finishing annealing equipment according to any one of claims 5 to 7, wherein the heating section also serves as a cooling section. 上記巻き戻しセクションが、巻き取りセクションを兼ねることを特徴とする請求項５〜８のいずれか１項に記載の仕上焼鈍設備。 The finishing annealing equipment according to any one of claims 5 to 8, wherein the rewinding section also serves as a winding section.
JP2010234226A 2010-10-19 2010-10-19 Finishing annealing method and finishing annealing equipment for grain-oriented electrical steel sheet Expired - Fee Related JP5896097B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2010234226A JP5896097B2 (en) 2010-10-19 2010-10-19 Finishing annealing method and finishing annealing equipment for grain-oriented electrical steel sheet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2010234226A JP5896097B2 (en) 2010-10-19 2010-10-19 Finishing annealing method and finishing annealing equipment for grain-oriented electrical steel sheet

Publications (2)

Publication Number Publication Date
JP2012087354A true JP2012087354A (en) 2012-05-10
JP5896097B2 JP5896097B2 (en) 2016-03-30

Family

ID=46259309

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2010234226A Expired - Fee Related JP5896097B2 (en) 2010-10-19 2010-10-19 Finishing annealing method and finishing annealing equipment for grain-oriented electrical steel sheet

Country Status (1)

Country Link
JP (1) JP5896097B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115505695A (en) * 2022-09-27 2022-12-23 中冶南方（武汉）热工有限公司 Annealing furnace for non-oriented silicon steel with extremely-thin specification

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63186824A (en) * 1987-01-28 1988-08-02 Nippon Steel Corp Finish annealing method for orientated silicon steel plate
JPH0533053A (en) * 1991-07-25 1993-02-09 Nippon Steel Corp Production of mirror face grain-oriented silicon steel strip
JPH05186835A (en) * 1991-07-25 1993-07-27 Nippon Steel Corp Production of mirror-finished grain-oriented silicon steel strip

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63186824A (en) * 1987-01-28 1988-08-02 Nippon Steel Corp Finish annealing method for orientated silicon steel plate
JPH0533053A (en) * 1991-07-25 1993-02-09 Nippon Steel Corp Production of mirror face grain-oriented silicon steel strip
JPH05186835A (en) * 1991-07-25 1993-07-27 Nippon Steel Corp Production of mirror-finished grain-oriented silicon steel strip

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115505695A (en) * 2022-09-27 2022-12-23 中冶南方（武汉）热工有限公司 Annealing furnace for non-oriented silicon steel with extremely-thin specification
CN115505695B (en) * 2022-09-27 2023-11-03 中冶南方（武汉）热工有限公司 Non-oriented silicon steel annealing furnace with extremely thin specification

Also Published As

Publication number Publication date
JP5896097B2 (en) 2016-03-30

Similar Documents

Publication Publication Date Title
JP5423909B1 (en) Method for producing grain-oriented electrical steel sheet
EP2743358B1 (en) Method for producing oriented magnetic steel sheet
JP2015175036A (en) Manufacturing method of oriented electromagnetic steel sheet
WO2010116936A1 (en) Method for treating steel for directional electromagnetic steel plate and method for producing directional electromagnetic steel plate
EP3431616B1 (en) Method of producing oriented magnetic steel sheet and production equipment line
JP5839204B2 (en) Method for producing grain-oriented electrical steel sheet
JP6721135B1 (en) Method for producing grain-oriented electrical steel sheet and cold rolling equipment
JP5896097B2 (en) Finishing annealing method and finishing annealing equipment for grain-oriented electrical steel sheet
JP2014156644A (en) Nitriding treatment facility for grain-oriented electromagnetic steel sheet, and nitriding treatment method
JP2016044322A (en) Batch annealing method for steel sheet coil
JP7031364B2 (en) Manufacturing method of grain-oriented electrical steel sheet
JP4609149B2 (en) Jig for final finish annealing of grain-oriented electrical steel sheet
JP4085975B2 (en) Hot rolling method
JP2693690B2 (en) Method and device for transporting unidirectional electrical steel sheet coil
JP6041110B2 (en) Method for producing grain-oriented electrical steel sheet with excellent iron loss characteristics
EP4335937A1 (en) Method for producing grain-oriented electrical steel sheet
JP4211540B2 (en) Continuous hot rolling mills for grain oriented electrical steel sheets
JP6376360B2 (en) Method for producing grain-oriented electrical steel sheet
JP4321248B2 (en) Continuous hot rolling equipment line
JP2012041605A (en) Manufacturing method of grain-oriented electromagnetic steel sheet
JPS61124528A (en) Manufacture of grain-oriented silicon steel sheet
JPH0633257A (en) Manufacture of thin grain-oriented silicon steel sheet
JPH08311559A (en) Production of grain oriented silicon steel sheet excellent in surface characteristic
JPH04325633A (en) Method and device for heat treatment of metal strip

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20130823

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20140319

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20140415

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20140613

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20150113

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20150313

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20150909

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20151015

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: 20160203

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20160216

R150 Certificate of patent or registration of utility model

Ref document number: 5896097

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees