JPH086032Y2 - Continuous annealing furnace with excellent atmosphere controllability - Google Patents
Continuous annealing furnace with excellent atmosphere controllabilityInfo
- Publication number
- JPH086032Y2 JPH086032Y2 JP1990122370U JP12237090U JPH086032Y2 JP H086032 Y2 JPH086032 Y2 JP H086032Y2 JP 1990122370 U JP1990122370 U JP 1990122370U JP 12237090 U JP12237090 U JP 12237090U JP H086032 Y2 JPH086032 Y2 JP H086032Y2
- Authority
- JP
- Japan
- Prior art keywords
- nitriding
- electric heater
- continuous annealing
- annealing furnace
- gas
- 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 - Lifetime
Links
Landscapes
- Resistance Heating (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
- Furnace Details (AREA)
Description
【考案の詳細な説明】 ［産業上の利用分野］ 本考案は雰囲気制御能が優れた連続焼鈍炉に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a continuous annealing furnace having excellent atmosphere controllability.
［従来の技術］ 一般に、連続焼鈍炉では加熱帯で加熱し、均熱帯で所
定温度に保持均熱する。この加熱作用は焼鈍されるスト
リップが表面性状を厳しく要求されるものや、高グレー
ドな品質特性を得るものでは、連続焼鈍における加熱は
例えば特開平１−142031号公報にあるような温度制御が
やすく、また雰囲気が汚染されにくい電気ヒータでなさ
れる。[Prior Art] Generally, in a continuous annealing furnace, heating is performed in a heating zone, and soaking is performed at a predetermined temperature in a soaking zone. This heating action is one in which the strip to be annealed is strictly required to have surface properties, and in the case of obtaining high-grade quality characteristics, the heating in continuous annealing is easy to control the temperature as in JP-A-1-142031, for example. Also, it is made with an electric heater that does not easily pollute the atmosphere.
ところで連続焼鈍では、例えばストリップを高強度化
するために窒化させることや、また、方向性電磁鋼板で
は窒化しインヒビターを形成すること等が行われる。こ
のような連続焼鈍では加熱は電気ヒータで行い、雰囲気
ガスから窒素を鋼中に侵入させ窒化している。By the way, in the continuous annealing, for example, nitriding of the strip in order to increase its strength, or nitriding of the grain-oriented electrical steel sheet to form an inhibitor is performed. In such continuous annealing, heating is performed with an electric heater, and nitrogen is introduced from the atmospheric gas into the steel for nitriding.
［考案が解決しようとする課題］ かかるストリップの高強度化やインヒビターの形成
を、従来の連続焼鈍炉で図るさい、窒化の程度に変動が
生じて強度向上代やインヒビターの形成量にバラツキが
あり、製品の特性がそれぞれ変動する。また所定窒化量
に窒化することが難しく所望の製品を得にくいという課
題がある。[Problems to be Solved by the Invention] In order to increase the strength of the strip and to form the inhibitor in the conventional continuous annealing furnace, the degree of nitriding varies, and there is variation in the strength improvement margin and the amount of the inhibitor formed. , Product characteristics vary. Further, there is a problem that it is difficult to nitrify to a predetermined nitriding amount and it is difficult to obtain a desired product.
［課題を解決するための手段］ 連続焼鈍炉で窒化するさいの変動を防止すべく実験し
検討したところ、窒化は加熱・均熱された温度域で雰囲
気中の窒化能ガス例えばNH3とストリップとの反応でな
されるが、前述の窒化量が変動したものでは雰囲気中に
占める窒化能ガスの濃度が変動することに起因している
ことを突き止めた。また、該変動は窒化能ガスの供給を
一定としていても生じていることが判明した。さらに検
討したところ次のことが明らかになった。[Means for Solving the Problems] An experiment and study were carried out to prevent fluctuations in nitriding in a continuous annealing furnace. Nitriding revealed that nitriding gas such as NH 3 and strip in the atmosphere in the heated and soaked temperature range. However, it was found that the variation in the nitriding amount is caused by the variation in the concentration of the nitriding gas in the atmosphere. It was also found that the fluctuation occurs even when the supply of the nitriding gas is constant. Further examination revealed the following.
一般に窒化の際はドライ雰囲気であり、このドライ雰
囲気中に窒化能ガスがある濃度（割合）で含まれてい
る。該ドライ雰囲気であるが故に窒化能ガス例えばNH3
が還元されたり、あるいは温度変化によっては酸化して
NH3濃度が変り、窒化に悪影響を及ぼしている。これらN
H3濃度の変動は、雰囲気中のNH3が加熱源の電気ヒータ
と反応しているのに起因していたことが知見された。Generally, nitriding is carried out in a dry atmosphere, and the nitriding gas is contained in this dry atmosphere at a certain concentration (ratio). Because of the dry atmosphere, a nitriding gas such as NH 3
Is reduced or is oxidized by temperature changes
The NH 3 concentration is changing, which has an adverse effect on nitriding. These N
It was found that the fluctuation of the H 3 concentration was caused by the reaction of NH 3 in the atmosphere with the electric heater of the heating source.
本考案は該知見に基づきなされたもので、その要旨は
金属ストリップを連続焼鈍しかつNH3によって窒化を行
う炉において、窒化を行う帯域の加熱装置として、ガス
無反応材をコーティングした電気ヒータまたはセラミッ
ク電気ヒータを設け、加熱あるいは均熱するようにした
ことを特徴とする雰囲気制御能力が優れた連続焼鈍炉に
ある。The present invention was made based on the above findings, and its gist is to use an electric heater coated with a gas non-reactive material as a heating device for a zone for nitriding in a furnace in which a metal strip is continuously annealed and nitrided with NH 3 . A continuous annealing furnace with excellent atmosphere control capability is characterized by being provided with a ceramic electric heater for heating or soaking.
以下、本考案について１実施例に基き図面を参照して
詳細に説明する。Hereinafter, the present invention will be described in detail with reference to the drawings based on an embodiment.
図面において、１は連続焼鈍炉で、この実施例では加
熱帯２、均熱帯３、冷却帯４が設けられている。加熱帯
２、均熱帯３にはガス無反応材をコーティングした電気
ヒータ５（以下コーティング電気ヒータという）が設け
られ、均熱帯３では窒化をも行うように窒化能ガス供給
ノズル６が配設されている。In the drawing, 1 is a continuous annealing furnace, and in this embodiment, a heating zone 2, a soaking zone 3, and a cooling zone 4 are provided. The heating zone 2 and the soaking zone 3 are provided with an electric heater 5 (hereinafter referred to as a coating electric heater) coated with a gas non-reactive material, and the soaking zone 3 is provided with a nitriding capacity gas supply nozzle 6 for nitriding. ing.
コーティング電気ヒータ５は、Ni−Cr系電気ヒータに
ガス無反応材例えばSiO2、Al2O3、Na2O等をコーティン
グしたものである。ガス無反応材としては前記実施例の
ものに限らず、窒化能ガス例えばNH3と反応しないもの
であれば如何なるものでも採用される。The coating electric heater 5 is a Ni—Cr electric heater coated with a gas non-reactive material such as SiO 2 , Al 2 O 3 or Na 2 O. The gas non-reactive material is not limited to those in the above-mentioned embodiment, and any material that does not react with the nitriding gas such as NH 3 may be used.
また、コーティング電気ヒータ５に替えて、セラミッ
ク電気ヒータを設けてもよい。Further, a ceramic electric heater may be provided instead of the coating electric heater 5.
これら、コーティング電気ヒータ５あるいはセラミッ
ク電気ヒータの配設位置は炉床、炉天井あるいは側壁な
ど任意の箇所に設けてよい。The coating electric heater 5 or the ceramic electric heater may be arranged at any position such as the hearth, the furnace ceiling or the side wall.
窒化能ガス供給ノズル６の配設は特定しないが、通板
方向からストリップ７に指向してガスを噴射せしめる向
きに設けることが望ましい。The arrangement of the nitriding gas supply nozzle 6 is not specified, but it is desirable to provide the nitriding gas supply nozzle 6 in the direction in which the gas is jetted from the sheet passing direction toward the strip 7.
しかして、均熱帯３ではストリップ７を加熱し均熱せ
しめるとともに、窒化能ガス例えばNH3がストリップと
反応しＮが鋼中に拡散侵入し窒化される。Then, in the soaking zone 3, the strip 7 is heated and soaked, and a nitriding gas such as NH 3 reacts with the strip so that N diffuses into the steel and is nitrided.
［作用］ ストリップ７が例えば方向性電磁鋼板でこれを窒化
し、インヒビターを形成する場合、磁気特性の優れたも
のを得るには所定量窒化する必要がある。ところで、本
考案の連続焼鈍炉１では加熱し均熱するさい、加熱作用
はコーティング電気ヒータ５で与えるので、窒化能ガス
供給ノズル６から噴射された窒化能ガス例えばNH3は該
コーティング電気ヒータ５と反応せず分解されない。ま
た窒化能ガスはそれ単独で供給されるのではなく、別に
N2やH2ガスが供給されている。[Operation] When the strip 7 is, for example, a grain-oriented electrical steel sheet and is nitrided to form an inhibitor, it is necessary to nitride a predetermined amount in order to obtain an excellent magnetic property. By the way, in the continuous annealing furnace 1 of the present invention, when heating and soaking, the heating action is given by the coating electric heater 5, so that the nitriding ability gas such as NH 3 injected from the nitriding ability gas supply nozzle 6 is supplied to the coating electric heater 5. It does not react with and is not decomposed. The nitriding gas is not supplied by itself, but separately.
N 2 or H 2 gas is being supplied.
一方、窒化は分解した後の状態では窒化能がなく、未
分解のNH3がストリップ７と接触反応してこそ安定した
窒化反応が生じる。またNH3が高温状態にあって本来分
解作用を与える電気ヒータが、NH3と反応しないコーテ
ィング電気ヒータ５とされているので、分解せず、雰囲
気ガス中のNH3濃度は第２図に供給NH3濃度と炉内NH3濃
度の関係を示すように変化しない。On the other hand, nitriding has no nitriding ability in the state after decomposition, and stable nitriding reaction occurs only when undecomposed NH 3 makes contact reaction with the strip 7. Further, since the electric heater that originally decomposes NH 3 at high temperature is the coating electric heater 5 that does not react with NH 3, it does not decompose and the NH 3 concentration in the atmosphere gas is supplied to FIG. NH 3 does not change to indicate the concentration and the furnace NH 3 concentration relationship.
これらの作用のためにストリップ７への窒化反応は安
定して生じる。Due to these effects, the nitriding reaction on the strip 7 occurs stably.
さらに、供給するNH3の割合を変えることにより、炉
内NH3濃度が高い精度で変えられ、窒化量のコントロー
ルが確実になされる。Furthermore, by changing the proportion of NH 3 supplied, the NH 3 concentration in the furnace can be changed with high accuracy, and the nitriding amount can be controlled reliably.
［考案の効果］ 以上のように、本考案による炉内の窒化能ガスが加熱
源の電気ヒータによって変化しないから、雰囲気が安定
しまたその制御が容易となり、窒化が確実になされる。[Effects of the Invention] As described above, the nitriding gas in the furnace according to the present invention is not changed by the electric heater of the heating source, so that the atmosphere is stable and its control is easy, and nitriding is surely performed.
第１図は本考案の１実施例を示す図、 第２図は本考案の作用を説明するための図、 である。 1:連続焼鈍炉、2:加熱帯、3:均熱帯、4:冷却帯、5:コー
ティング電気ヒータ、6:窒化能ガス供給ノズル、7:スト
リップ。FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation of the present invention. 1: Continuous annealing furnace, 2: Heating zone, 3: Soaking zone, 4: Cooling zone, 5: Coating electric heater, 6: Nitriding gas supply nozzle, 7: Strip.
───────────────────────────────────────────────────── フロントページの続き (72)考案者 松尾 三郎 福岡県北九州市戸畑区飛幡町１番１号 新 日本製鐵株式会社八幡製鐵所内 (56)参考文献 特開 昭51−77938（ＪＰ，Ａ) 特開 昭61−179084（ＪＰ，Ａ) 特開 平２−186586（ＪＰ，Ａ) 実開 昭56−42967（ＪＰ，Ｕ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Saburo Matsuo 1-1 Hibahata-machi, Tobata-ku, Kitakyushu, Kitakyushu, Fukuoka Inside Nippon Steel Co., Ltd. Yawata Works (56) Reference JP-A-51-77938 (JP, A) JP-A-61-179084 (JP, A) JP-A-2-186586 (JP, A) Actual development Sho-56-42967 (JP, U)
Claims (1)
って窒化を行う炉において、窒化を行う帯域の加熱装置
として、ガス無反応材をコーティングした電気ヒータま
たはセラミック電気ヒータを設けたことを特徴とする雰
囲気制御能が優れた連続焼鈍炉。1. A furnace for continuously annealing a metal strip and nitriding with NH 3 , wherein an electric heater coated with a gas non-reactive material or a ceramic electric heater is provided as a heating device for a zone for nitriding. A continuous annealing furnace with excellent atmosphere controllability.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1990122370U JPH086032Y2 (en) | 1990-11-26 | 1990-11-26 | Continuous annealing furnace with excellent atmosphere controllability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1990122370U JPH086032Y2 (en) | 1990-11-26 | 1990-11-26 | Continuous annealing furnace with excellent atmosphere controllability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0481957U JPH0481957U (en) | 1992-07-16 |
| JPH086032Y2 true JPH086032Y2 (en) | 1996-02-21 |
Family
ID=31870154
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1990122370U Expired - Lifetime JPH086032Y2 (en) | 1990-11-26 | 1990-11-26 | Continuous annealing furnace with excellent atmosphere controllability |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH086032Y2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5177938A (en) * | 1974-12-27 | 1976-07-06 | Toshiba Ceramics Co | TANKAKEISOHATSUNETSUTAINO HOGOHIMAKUKEISEIHOHO |
| JP2727342B2 (en) * | 1989-01-13 | 1998-03-11 | 東芝セラミックス株式会社 | Method for forming oxidation-resistant coating on SiC heating element |
-
1990
- 1990-11-26 JP JP1990122370U patent/JPH086032Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0481957U (en) | 1992-07-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100277156B1 (en) | Method and Equipment for Vacuum Carburization and Products of Carburization | |
| Gräfen et al. | New developments in thermo-chemical diffusion processes | |
| GB1471880A (en) | Furnace atmosphere for the heat treatment of ferrous metal | |
| AU554394B2 (en) | (carbo) nitriding and case hardening of steels | |
| US4152177A (en) | Method of gas carburizing | |
| JPH086032Y2 (en) | Continuous annealing furnace with excellent atmosphere controllability | |
| US4208224A (en) | Heat treatment processes utilizing H2 O additions | |
| US4359351A (en) | Protective atmosphere process for annealing and or spheroidizing ferrous metals | |
| US4211584A (en) | Methods of heat-treating steel | |
| JPH08260059A (en) | Continuous annealing furnace excellent in atmosphere control ability | |
| US1944743A (en) | Method for annealing steel | |
| ES270590A1 (en) | Production of non-oriented ferrous magnetic materials | |
| Wirtnik | High-performance hydrogen annealing | |
| JPH089157Y2 (en) | Continuous decarburization annealing furnace | |
| JPH0578736A (en) | Continuous decarburized annealing method of silicon steel strip | |
| ES2080416T3 (en) | PROCEDURE FOR THE TREATMENT OF STEELS AND REFRACTORY METALS. | |
| JPS6214008B2 (en) | ||
| JPH03260048A (en) | Rapid gas nitriding method | |
| JP3509405B2 (en) | Improvement of furnace atmosphere in continuous heat treatment furnace for steel strip | |
| JPS55125227A (en) | Toughening method of small steel member for case hardening | |
| SU945244A1 (en) | Method for nitriding | |
| SU595400A1 (en) | Method of obtaining protective atmosphere for oxidation-free heating of metal | |
| JPS6360095B2 (en) | ||
| JPS5655520A (en) | Production of surface decarbonized high carbon steel strip | |
| JPS60255919A (en) | Method for preventing nitriding in annealing stainless steel |