JP3509405B2 - Improvement of furnace atmosphere in continuous heat treatment furnace for steel strip - Google Patents
Improvement of furnace atmosphere in continuous heat treatment furnace for steel stripInfo
- Publication number
- JP3509405B2 JP3509405B2 JP21675696A JP21675696A JP3509405B2 JP 3509405 B2 JP3509405 B2 JP 3509405B2 JP 21675696 A JP21675696 A JP 21675696A JP 21675696 A JP21675696 A JP 21675696A JP 3509405 B2 JP3509405 B2 JP 3509405B2
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- atmosphere
- steel strip
- concentration
- heat treatment
- 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.)
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Description
【発明の詳細な説明】
【０００１】
【発明が属する技術分野】本発明は、無酸化ガス雰囲気
の連続熱処理炉において鋼帯を連続的に熱処理する定常
操業を行うに先立ち、若しくは定常操業中に炉内雰囲気
中の水分濃度及び／または酸素濃度が上昇した際に、炉
内雰囲気中の水分濃度および／または酸素濃度を定常操
業に適したレベルまで低減させるための炉内雰囲気改善
方法に関する。
【０００２】
【従来の技術】従来、鋼帯を無酸化ガス雰囲気中で熱処
理するための連続熱処理炉において、炉の大気開放後の
立ち上げ時や炉内雰囲気に大気が侵入した場合等に炉内
の水分や酸素濃度を低減させるには、炉内温度を上昇さ
せることにより炉内の水分を気化させ、これと相前後し
て不活性ガス等の無酸化性ガスを炉内雰囲気の置換ガス
として炉内に供給し、同時に炉内のガスを排気すること
で炉内雰囲気を無酸化性ガスに置換する方法が広く行わ
れている。
【０００３】
【発明が解決しようとする課題】しかし、このような従
来の方法では、炉内雰囲気中の水分や酸素濃度を定常操
業に適した所定のレベルまで減少させるのに長時間を要
し、その間は操業ができないため、連続熱処理炉の生産
性を著しく低下させるという問題がある。したがって本
発明の目的は、無酸化ガス雰囲気の熱処理炉において鋼
帯を連続的に熱処理する定常操業を行うに先立ち、若し
くは定常操業中に炉内雰囲気中の水分濃度及び／または
酸素濃度が上昇した際に、炉内雰囲気中の水分濃度およ
び／または酸素濃度を定常操業に適したレベルまで速や
かに低減させことができる炉内雰囲気改善方法を提供す
ることにある。
【０００４】
【課題を解決するための手段】このような目的を達成す
るための本発明は、無酸化ガス雰囲気の熱処理炉におい
て鋼帯を連続的に通板させて熱処理する定常操業を行う
に先立ち、若しくは定常操業中に炉内雰囲気中の水分濃
度及び／または酸素濃度が上昇した際に、炉内雰囲気中
の水分濃度および／または酸素濃度を低減させる方法に
おいて、無酸化性ガスを炉内供給して炉内雰囲気の置換
を行うとともに、これと並行して鋼中炭素濃度が６０ｐ
ｐｍ以上の鋼帯を炉内に通板させ、９００〜１３００℃
の温度で該鋼帯の鋼中炭素と炉内雰囲気中の水分及び／
または酸素を反応させ、炉内雰囲気中の水分濃度及び／
または酸素濃度を低減させることを特徴とする鋼帯の連
続熱処理炉における炉内雰囲気改善方法である。
【０００５】
【発明の実施の形態】本発明法では、無酸化ガス雰囲気
の熱処理炉において鋼帯を連続的に熱処理する定常操業
を行うに先立ち、若しくは定常操業中に炉内雰囲気中の
水分濃度及び／または酸素濃度が上昇した際に、以下の
ようにして炉内雰囲気の改善を行う。すなわち、通常は
炉内温度を上昇させて炉内の水分を気化させ、これと相
前後して無酸化性ガス（不活性ガス等）を炉内供給する
と同時に炉内のガスを排気する炉内雰囲気の置換を行う
が、この炉内雰囲気の置換と並行して鋼中炭素濃度が６
０ｐｐｍ以上の鋼帯を炉内に通板させ、この鋼帯の鋼中
炭素と炉内雰囲気中の水分及び／または酸素を反応させ
る。この鋼帯は炉内雰囲気中の水分や酸素濃度を低減さ
せるためだけに通板させる言わばダミーの鋼帯であり、
機能的には、炉内雰囲気中の水分や酸素と反応（鋼帯側
では脱炭反応）させてこれをＣＯの生成に消費するため
の炭素を炉内に連続的に供給する役目を果たす。
【０００６】例えば、炉内雰囲気中の水分に関して言え
ば、Ｈ2Ｏは下記（１）式に示すように鋼帯中の炭素と
反応してＣＯを生成させる。
Ｃ＋Ｈ2Ｏ→ＣＯ＋Ｈ2 …（１）
このように無酸化性ガスによる炉内雰囲気の置換中、上
記（１）式の反応によって炉内雰囲気中の水分や酸素が
ＣＯの生成のために急速に消費されるため、炉内雰囲気
中の水分や酸素濃度は速やかに低減する。したがって、
炉内雰囲気の置換だけで水分や酸素濃度を低減させてい
た従来法に較べ、炉内雰囲気中の水分や酸素濃度を極く
短時間のうちに定常操業に適したレベルまで低減させる
ことができる。なお、炉内雰囲気の置換と相前後して行
われる炉内の昇温は、無酸化性ガスの炉内への供給前ま
たは供給後のいずれでもよく、また供給と同時に行って
もよい。
【０００７】上記の反応により炉内雰囲気中の水分や酸
素濃度を効率的に低減させるためには、炉内に通板させ
る鋼帯中に炉内雰囲気中の水分や酸素と反応するための
十分な量の炭素が存在することが必要である。本発明者
らによる実験の結果、通板前の鋼中炭素濃度が６０ｐｐ
ｍ以上の鋼帯であれば、上記の反応が効率的に進行する
ことが判った。したがって、炉内に通板させる鋼帯は、
鋼中炭素濃度が６０ｐｐｍ以上のものとする。なお、鋼
帯には炉内雰囲気中の水分や酸素と反応するに十分な量
の炭素が存在すればよいので、鋼中炭素濃度の上限は特
に設けない。
【０００８】鋼帯中の炭素と炉内雰囲気中の水分や酸素
との反応の効率は、反応温度に大きく依存しており、炉
内温度が９００℃未満では上記の反応が速やかに進行せ
ず、一方、１３００℃を超えると鋼帯の強度が低下する
ため連続通板が困難となり、鋼帯の破断時の原因にもな
る。このため、鋼帯を通板させる際の炉内温度は９００
〜１３００℃とする必要がある。また、特に上記の反応
を速やかに行わせ、炉内雰囲気中の水分や酸素濃度を効
率的に低減させるためには、炉内温度を１２００℃以上
とすることが好ましい。また、炉内雰囲気中の水分や酸
素と鋼中炭素との反応量は鋼帯の炉内での滞留時間に依
存し、鋼帯の炉内での滞留時間は長いほどよい。したが
って、炉内雰囲気中の水分濃度及び酸素濃度、鋼帯の鋼
中炭素量、炉内温度、炉長等に応じて鋼帯の通板速度が
適宜選択される。
【０００９】本発明法は、連続焼鈍炉や浸珪処理炉をは
じめとする各種の連続熱処理炉に適用することができ
る。また、本発明法は無酸化ガス雰囲気の熱処理炉にお
いて鋼帯を連続的に熱処理する定常操業を行うに先立っ
て実施されるか、若しくは定常操業中に炉内雰囲気中の
水分濃度及び／または酸素濃度が上昇した際に実施され
るものであるが、具体的には次のようなケースが例示で
きる。
(1) 熱処理炉の建造後の立上時、或いは熱処理炉の修理
等のために炉を大気開放した後の再立上時
(2) 定常操業時に、熱処理炉の炉周辺設備の異常等によ
り水や空気等が炉内に多量に浸入した場合
(3) 定常操業時に、上記(2)以外の原因で露点が変動
し、露点が悪化した場合
【００１０】
【実施例】図１に示すような、入側から順に加熱帯１、
浸珪処理帯２、均熱帯３、冷却帯４を備えた連続浸珪処
理炉において、本発明例及び比較例の方法を実施した。
なお、この連続浸珪処理炉の定常操業では、鋼帯Ｓを加
熱帯１において加熱した後、ＳｉＣｌ4を含む無酸化性
ガス雰囲気の浸珪処理帯２において鋼帯Ｓに化学気相蒸
着による浸珪処理を施し、次いでＳｉＣｌ4を含まない
無酸化性ガス雰囲気の均熱帯において、浸珪処理で鋼帯
表面に浸透したＳｉを板厚方向に拡散させる熱処理を施
し、しかる後、冷却帯で冷却して高珪素鋼帯を製造す
る。
【００１１】このような連続浸珪処理炉において、炉を
大気開放した後、操業を再開する際に、無酸化性ガス
（窒素）を炉内供給して炉内雰囲気の置換を行うととも
に、これと並行して鋼中炭素濃度が異なる各種鋼帯（但
し、各鋼帯は単位長さ当りの表面積が同一）を炉内に一
定速度で通板させ、通板開始直後からの炉内雰囲気中の
水分濃度の変化を測定した。また、鋼帯を通板させるこ
となく炉内雰囲気の置換のみで炉内水分濃度を低減させ
る比較例も実施した。通板した鋼帯は、鋼中炭素濃度が
２０ｐｐｍ、６０ｐｐｍ、１１０ｐｐｍ、７００ｐｐｍ
の４水準とした。また、鋼板を通板させた際の炉内温度
は１２００℃とした。
【００１２】その結果を図２に示す。同図によれば、炉
内雰囲気の置換だけで水分濃度を低減させる方法（従来
法）では、水分濃度を２００ｐｐｍのレベルまで低下さ
せるのに１２０時間以上かかるのに対して、炉内雰囲気
の置換と並行して鋼中炭素濃度が６０ｐｐｍ以上の鋼帯
を炉内に通板させる本発明法では、略半分の６０時間程
度で水分濃度を２００ｐｐｍのレベルまで低下させるこ
とができ、また、鋼中炭素濃度がさらに高い鋼帯を通板
させることにより、より短時間で水分濃度を目標のレベ
ルまで低減させ得ることが判る。
【００１３】
【発明の効果】以上述べた本発明によれば、無酸化ガス
雰囲気の熱処理炉において鋼帯を連続的に熱処理する定
常操業を行うに先立ち、若しくは定常操業中に炉内雰囲
気中の水分濃度及び／または酸素濃度が上昇した際に、
炉内雰囲気中の水分濃度および／または酸素濃度を低減
させる場合、炉内雰囲気の置換だけで水分や酸素濃度を
低減させていた従来法に較べ、炉内雰囲気中の水分や酸
素濃度を極く短時間のうちに定常操業に適したレベルま
で減少させることができる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous heat treatment of a steel strip in a continuous heat treatment furnace in a non-oxidizing gas atmosphere before or during a steady operation. The present invention relates to a furnace atmosphere improving method for reducing the moisture concentration and / or oxygen concentration in a furnace atmosphere to a level suitable for a steady operation when the moisture concentration and / or oxygen concentration in the furnace atmosphere increases. 2. Description of the Related Art Conventionally, in a continuous heat treatment furnace for heat treating a steel strip in an atmosphere of non-oxidizing gas, when the furnace is started up after the furnace is opened to the atmosphere or when the atmosphere enters the furnace atmosphere, the furnace is used. In order to reduce the moisture and oxygen concentration in the furnace, the furnace temperature is increased to evaporate the water in the furnace, and around this time, a non-oxidizing gas such as an inert gas is replaced with a replacement gas in the furnace atmosphere. A method has been widely used in which the atmosphere in the furnace is replaced with a non-oxidizing gas by supplying the gas into the furnace and simultaneously exhausting the gas in the furnace. However, in such a conventional method, it takes a long time to reduce the moisture and oxygen concentrations in the furnace atmosphere to a predetermined level suitable for a steady operation. However, since the operation cannot be performed during that time, there is a problem that the productivity of the continuous heat treatment furnace is significantly reduced. Therefore, an object of the present invention is to increase the water concentration and / or oxygen concentration in the furnace atmosphere before or during the steady operation of continuously heat treating the steel strip in the heat treatment furnace in the non-oxidizing gas atmosphere. In this case, it is an object of the present invention to provide a furnace atmosphere improving method capable of rapidly reducing the moisture concentration and / or oxygen concentration in the furnace atmosphere to a level suitable for a steady operation. [0004] Means for Solving the Problems The present invention to achieve the above object, to do steady operation of the heat treatment continuously by passing plate strip in a heat treatment furnace of non-oxidizing gas atmosphere In a method for reducing the water concentration and / or oxygen concentration in the furnace atmosphere before or when the water concentration and / or oxygen concentration in the furnace atmosphere rises during normal operation, the non-oxidizing gas is removed from the furnace. To replace the atmosphere in the furnace, and at the same time, the carbon concentration
pm or more is passed through the furnace, 900 ~ 1300 ℃
At the temperature of carbon in the steel strip and the moisture in the furnace atmosphere and / or
Alternatively, oxygen is reacted and the water concentration in the furnace atmosphere and / or
Alternatively, it is a method for improving the atmosphere in a furnace in a continuous heat treatment furnace for a steel strip, characterized by reducing the oxygen concentration. [0005] In the method of the present invention, the moisture concentration in the atmosphere in the furnace prior to or during the steady operation of continuously heat treating a steel strip in a heat treatment furnace in an oxidizing gas atmosphere. And / or when the oxygen concentration increases, the atmosphere in the furnace is improved as follows. That is, usually, the furnace temperature is increased to evaporate the moisture in the furnace, and at the same time, a non-oxidizing gas (such as an inert gas) is supplied into the furnace and the furnace gas is simultaneously exhausted. Atmosphere replacement is performed, and in parallel with the furnace atmosphere replacement, the carbon concentration in steel is reduced to 6%.
A steel strip of 0 ppm or more is passed through the furnace, and carbon in the steel of the steel strip reacts with moisture and / or oxygen in the furnace atmosphere. This steel strip is a dummy steel strip that is passed through only to reduce the moisture and oxygen concentrations in the furnace atmosphere.
Functionally, it plays a role of continuously supplying carbon to the furnace in order to react with moisture and oxygen in the furnace atmosphere (a decarburization reaction on the steel strip side) and to consume it for the generation of CO into the furnace. For example, regarding the moisture in the furnace atmosphere, H 2 O reacts with carbon in the steel strip to generate CO as shown in the following equation (1). C + H 2 O → CO + H 2 (1) As described above, during the replacement of the furnace atmosphere by the non-oxidizing gas, the water and oxygen in the furnace atmosphere are rapidly generated due to the reaction of the above formula (1) due to the generation of CO. Since it is consumed, the moisture and oxygen concentrations in the furnace atmosphere are rapidly reduced. Therefore,
Moisture and oxygen concentrations in the furnace atmosphere can be reduced to levels suitable for steady-state operation in a very short time, compared to the conventional method in which the moisture and oxygen concentrations were reduced simply by replacing the furnace atmosphere. . The temperature increase in the furnace before or after the replacement of the furnace atmosphere may be performed before or after the supply of the non-oxidizing gas into the furnace, or may be performed simultaneously with the supply. [0007] In order to efficiently reduce the moisture and oxygen concentrations in the furnace atmosphere by the above-mentioned reaction, a steel strip passed through the furnace must have a sufficient amount of water and oxygen to react with the moisture and oxygen in the furnace atmosphere. It is necessary that a significant amount of carbon be present. As a result of the experiment by the present inventors, the carbon concentration in the steel before passing was 60 pp.
It was found that the above reaction proceeded efficiently with a steel strip of m or more. Therefore, the steel strip passed through the furnace is
The carbon concentration in steel shall be 60 ppm or more. Since the steel strip only needs to contain a sufficient amount of carbon to react with moisture and oxygen in the furnace atmosphere, no upper limit is set for the carbon concentration in the steel. [0008] The efficiency of the reaction between carbon in the steel strip and moisture or oxygen in the furnace atmosphere greatly depends on the reaction temperature. If the furnace temperature is lower than 900 ° C, the above reaction does not proceed rapidly. On the other hand, when the temperature exceeds 1300 ° C., the strength of the steel strip is reduced, so that it is difficult to continuously pass the steel strip, and this also causes a break in the steel strip. For this reason, the furnace temperature at the time of passing the steel strip is 900
と す る 1300 ° C. In particular, the temperature in the furnace is preferably set to 1200 ° C. or higher in order to promptly perform the above reaction and efficiently reduce the moisture and oxygen concentrations in the furnace atmosphere. In addition, the amount of reaction between water and oxygen in the furnace atmosphere and carbon in the steel depends on the residence time of the steel strip in the furnace, and the longer the residence time of the steel strip in the furnace, the better. Therefore, the passing speed of the steel strip is appropriately selected according to the moisture concentration and oxygen concentration in the furnace atmosphere, the amount of carbon in the steel of the steel strip, the furnace temperature, the furnace length, and the like. The method of the present invention can be applied to various continuous heat treatment furnaces such as a continuous annealing furnace and a siliconizing furnace. Further, the method of the present invention is carried out prior to performing a steady operation for continuously heat treating a steel strip in a heat treatment furnace in an oxidizing gas atmosphere, or during a steady operation, the water concentration and / or oxygen concentration in the furnace atmosphere is changed. This is carried out when the concentration increases, and specifically, the following cases can be exemplified. (1) At the time of start-up after the construction of the heat treatment furnace, or at the time of re-startup after opening the furnace for repair of the heat treatment furnace, etc. (2) At the time of normal operation, due to an abnormality in the furnace peripheral equipment of the heat treatment furnace, etc. When a large amount of water or air enters the furnace (3) When the dew point fluctuates due to factors other than the above (2) during normal operation and the dew point deteriorates [Example] As shown in FIG. Na, heating zone 1,
The method of the present invention example and the comparative example were carried out in a continuous siliconizing furnace having a siliconizing zone 2, a soaking zone 3, and a cooling zone 4.
In the continuous operation of the continuous siliconizing furnace, the steel strip S is heated in the heating zone 1, and then the steel strip S is subjected to chemical vapor deposition in the siliconizing zone 2 in a non-oxidizing gas atmosphere containing SiCl 4. In a uniform tropic atmosphere in a non-oxidizing gas atmosphere containing no SiCl 4 , a heat treatment for diffusing Si permeated into the steel strip surface in the sheet thickness direction by the siliconizing treatment is performed, and then, in a cooling zone. Cool to produce high silicon steel strip. In such a continuous siliconizing furnace, when the furnace is opened to the atmosphere and operation is resumed, a non-oxidizing gas (nitrogen) is supplied into the furnace to replace the furnace atmosphere. In parallel with the above, various steel strips with different carbon concentrations in the steel (however, each steel strip has the same surface area per unit length) are passed through the furnace at a constant speed. The change in water concentration was measured. In addition, a comparative example in which the furnace water concentration was reduced only by replacing the furnace atmosphere without passing the steel strip through was performed. The passed steel strip has a carbon concentration in steel of 20 ppm, 60 ppm, 110 ppm, and 700 ppm.
4 levels. The furnace temperature when the steel sheet was passed was set to 1200 ° C. FIG. 2 shows the results. According to the figure, in the method of reducing the water concentration only by replacing the furnace atmosphere (conventional method), it takes 120 hours or more to reduce the water concentration to the level of 200 ppm, whereas the replacement of the furnace atmosphere is performed. According to the method of the present invention in which a steel strip having a carbon concentration of 60 ppm or more in steel is passed through the furnace in parallel with the above, the water concentration can be reduced to a level of 200 ppm in about half of 60 hours. It can be seen that the water concentration can be reduced to the target level in a shorter time by passing the steel strip having a higher carbon concentration through the steel strip. According to the present invention described above, prior to or during the steady operation of continuously heat-treating the steel strip in the heat treatment furnace in the non-oxidizing gas atmosphere, the temperature in the furnace atmosphere is reduced. When the water and / or oxygen concentration increases,
When reducing the moisture concentration and / or oxygen concentration in the furnace atmosphere, the moisture and oxygen concentrations in the furnace atmosphere are extremely reduced compared to the conventional method in which the moisture and oxygen concentrations are reduced only by replacing the furnace atmosphere. It can be reduced to a level suitable for steady operation in a short time.
【図面の簡単な説明】
【図１】実施例で用いた連続浸珪処理炉の構成を示す説
明図
【図２】実施例における鋼帯通板開始直後からの炉内雰
囲気中の水分濃度の変化を示すグラフ
【符号の説明】
１…加熱炉、２…浸珪処理炉、３…均熱炉、４…冷却炉BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing the configuration of a continuous siliconizing furnace used in the embodiment. FIG. 2 is a diagram showing the moisture concentration in the furnace atmosphere immediately after the start of steel strip passing in the embodiment. Graph showing change [Explanation of symbols] 1 ... heating furnace, 2 ... siliconizing furnace, 3 ... soaking furnace, 4 ... cooling furnace
───────────────────────────────────────────────────── フロントページの続き (72)発明者 平谷 多津彦 東京都千代田区丸の内一丁目１番２号 日本鋼管株式会社内 (56)参考文献 特開 平２−200723（ＪＰ，Ａ) 特開 平４−304309（ＪＰ，Ａ) 特開 昭58−167721（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C21D 1/76 C21D 9/52 - 9/66 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tatsuhiko Hiratani 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (56) References JP-A-2-200723 (JP, A) JP-A Hei 4-304309 (JP, A) JP-A-58-167721 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C21D 1/76 C21D 9/52-9/66
Claims (1)
帯を連続的に通板させて熱処理する定常操業を行うに先
立ち、若しくは定常操業中に炉内雰囲気中の水分濃度及
び／または酸素濃度が上昇した際に、炉内雰囲気中の水
分濃度及び／または酸素濃度を低減させる方法におい
て、無酸化性ガスを炉内供給して炉内雰囲気の置換を行
うとともに、これと並行して鋼中炭素濃度が６０ｐｐｍ
以上の鋼帯を炉内に通板させ、９００〜１３００℃の温
度で該鋼帯の鋼中炭素と炉内雰囲気中の水分及び／また
は酸素を反応させ、炉内雰囲気中の水分濃度及び／また
は酸素濃度を低減させることを特徴とする鋼帯の連続熱
処理炉における炉内雰囲気改善方法。(57) [Claims 1] In a heat treatment furnace in a non-oxidizing gas atmosphere, prior to performing a steady operation of continuously passing a steel strip through a heat treatment, or in a furnace atmosphere during a steady operation. A method for reducing the water concentration and / or oxygen concentration in the furnace atmosphere when the water concentration and / or oxygen concentration of the furnace rises. In parallel with this, the carbon concentration in steel is 60 ppm
The above steel strip is passed through a furnace, and the carbon in the steel of the steel strip reacts with the water and / or oxygen in the furnace atmosphere at a temperature of 900 to 1300 ° C., and the water concentration and / or Alternatively, a method for improving an atmosphere in a furnace in a continuous heat treatment furnace for a steel strip, characterized by reducing an oxygen concentration.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21675696A JP3509405B2 (en) | 1996-07-30 | 1996-07-30 | Improvement of furnace atmosphere in continuous heat treatment furnace for steel strip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21675696A JP3509405B2 (en) | 1996-07-30 | 1996-07-30 | Improvement of furnace atmosphere in continuous heat treatment furnace for steel strip |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1046237A JPH1046237A (en) | 1998-02-17 |
| JP3509405B2 true JP3509405B2 (en) | 2004-03-22 |
Family
ID=16693433
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21675696A Expired - Fee Related JP3509405B2 (en) | 1996-07-30 | 1996-07-30 | Improvement of furnace atmosphere in continuous heat treatment furnace for steel strip |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3509405B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5071551B2 (en) * | 2010-12-17 | 2012-11-14 | Ｊｆｅスチール株式会社 | Continuous annealing method for steel strip, hot dip galvanizing method |
-
1996
- 1996-07-30 JP JP21675696A patent/JP3509405B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1046237A (en) | 1998-02-17 |
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