JPS63130718A - Continuous annealing method for steel strip - Google Patents
Continuous annealing method for steel stripInfo
- Publication number
- JPS63130718A JPS63130718A JP27775286A JP27775286A JPS63130718A JP S63130718 A JPS63130718 A JP S63130718A JP 27775286 A JP27775286 A JP 27775286A JP 27775286 A JP27775286 A JP 27775286A JP S63130718 A JPS63130718 A JP S63130718A
- Authority
- JP
- Japan
- Prior art keywords
- steel strip
- heating
- oxide film
- reducing
- air ratio
- 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.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 104
- 239000010959 steel Substances 0.000 title claims abstract description 104
- 238000000137 annealing Methods 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims description 18
- 238000010438 heat treatment Methods 0.000 claims abstract description 38
- 238000002485 combustion reaction Methods 0.000 claims abstract description 16
- 239000010408 film Substances 0.000 claims description 24
- 238000005507 spraying Methods 0.000 claims description 7
- 239000010409 thin film Substances 0.000 claims description 5
- 239000012298 atmosphere Substances 0.000 abstract description 24
- 230000001590 oxidative effect Effects 0.000 abstract description 20
- 238000002791 soaking Methods 0.000 abstract description 5
- 238000007664 blowing Methods 0.000 abstract description 3
- 239000000571 coke Substances 0.000 abstract description 3
- 239000000446 fuel Substances 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 22
- 239000007921 spray Substances 0.000 description 9
- 239000002737 fuel gas Substances 0.000 description 8
- 238000001816 cooling Methods 0.000 description 5
- 239000000047 product Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000007667 floating Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 241000218691 Cupressaceae Species 0.000 description 1
- 229910015189 FeOx Inorganic materials 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000013067 intermediate product Substances 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Abstract
Description
【発明の詳細な説明】
〈発明の目的〉
産業上の利用分野
本発明は鋼帯の連続焼鈍方法に係り、詳しくは、直火式
連続焼鈍炉において、帯鋼板に酸化膜を付着させること
なく、連続焼鈍する鋼帯の連続焼鈍方法に係る。[Detailed Description of the Invention] <Object of the Invention> Industrial Field of Application The present invention relates to a method for continuous annealing of steel strips, and more specifically, the present invention relates to a method for continuous annealing of steel strips, and more specifically, the present invention relates to a method for continuous annealing of steel strips, and more specifically, annealing methods for continuous annealing of steel strips without attaching an oxide film to the steel strips in a direct-fired continuous annealing furnace. , relates to a continuous annealing method for continuously annealing steel strip.
従来の技術
従来、優れた外観、表面性状を具備する薄鋼帯の連続焼
鈍方法においては、加熱に際し、非酸化雰囲気炉内での
輻射管式バーナによる無酸化雰囲気中での間接加熱が行
なわれ、また、特開昭５５−９１９４３号にみられるよ
うに、輻射管式バーナによる間接加熱に代り、設備費、
操作コストの節減、急速加熱および炉長短縮等を目的と
して直火式バーナによる直接加熱により鋼帯を加熱した
後、鋼帯表面に生成した酸化皮膜を低水素濃度雰囲気中
で還元する方法が採用されている。なお、前記直火加熱
においては、空気比１．０以下の燃焼により弱酸化性雰
囲気にすることが一般に実施されている。Conventional technology Conventionally, in the continuous annealing method for thin steel strips with excellent appearance and surface properties, indirect heating was performed in a non-oxidizing atmosphere using a radiant tube burner in a non-oxidizing atmosphere furnace. In addition, as seen in Japanese Patent Application Laid-Open No. 55-91943, instead of indirect heating using a radiant tube burner, equipment costs,
For the purpose of reducing operating costs, rapid heating, and shortening the furnace length, a method has been adopted in which the steel strip is heated by direct heating using a direct-fired burner, and then the oxide film formed on the surface of the steel strip is reduced in an atmosphere with a low hydrogen concentration. has been done. In addition, in the above-mentioned direct flame heating, it is generally practiced to create a weakly oxidizing atmosphere by combustion at an air ratio of 1.0 or less.
しかし、前記の直火加熱−還元による連続焼鈍方法にお
いては、次の問題点があった。すなわち、（１）空気比
１．０以下の燃焼による弱酸化雰囲気中であっても、特
開昭５５−９１９４３号公報の第２図（ａ）の如く直火
炉出口の鋼帯温度の上昇と共に酸化膜厚みが増加するた
め、実用上鋼帯温度４００〜６００℃までの直火加熱に
とどめる必要がある。（２）鋼帯を、さらに高温まで加
熱する場合や表面性状の優れた鋼帯を得るためには、直
火加熱後に還元性雰囲気の輻射管式バーナによる間接加
熱帯あるいは還元帯を設ける必要があり、設備費の増大
、水素等雰囲気ガス原単位の増加を招く欠点があった。However, the continuous annealing method using direct flame heating and reduction has the following problems. That is, (1) Even in a weakly oxidizing atmosphere due to combustion with an air ratio of 1.0 or less, as the temperature of the steel strip at the outlet of the direct-fired furnace increases, as shown in Fig. 2 (a) of JP-A No. 55-91943, Since the oxide film thickness increases, it is practically necessary to limit the steel strip temperature to direct flame heating of 400 to 600°C. (2) In order to heat the steel strip to a higher temperature or to obtain a steel strip with excellent surface properties, it is necessary to provide an indirect heating zone or reduction zone using a radiant tube burner in a reducing atmosphere after direct heating. However, there were drawbacks such as an increase in equipment costs and an increase in the consumption of atmospheric gases such as hydrogen.
発明が解決しようとする問題点
本発明はこれらの問題点の解決を目的とし、具体的には
、直火式連続焼鈍炉において鋼帯を酸化させることなく
高；晶まで加熱することのできる鋼帯の連続焼鈍方法を
提供することを目的とする。Problems to be Solved by the Invention The present invention aims to solve these problems, and specifically, to provide a steel that can be heated to a high crystallinity without oxidizing the steel strip in a direct-fired continuous annealing furnace. The object of the present invention is to provide a method for continuous annealing of a strip.
〈発明の構成〉
問題点を解決するための
手段ならびにその作用
本発明は、横型連続焼鈍炉によって鋼帯を直火加熱する
際に、鋼帯温度が４００ ℃以上では燃焼用空気比を１
．０未満として燃焼させて鋼帯を加熱すると共に、還元
性ガスを前記鋼帯の上下面を薄膜状に被覆するように吹
付け、鋼帯表面の酸化膜を還元して加熱することを特徴
とする。<Structure of the Invention> Means for Solving the Problems and Their Effects The present invention provides a method for reducing the combustion air ratio to 1 when the temperature of the steel strip is 400°C or higher when directly heating the steel strip in a horizontal continuous annealing furnace.
．． The steel strip is heated by burning the steel strip at a temperature of less than 0, and a reducing gas is sprayed to cover the upper and lower surfaces of the steel strip in a thin film form, thereby reducing the oxide film on the surface of the steel strip and heating the steel strip. do.
以下、図面によって本発明の手段たる構成ならびに作用
を説明すると、次の通りである。Hereinafter, the structure and operation of the means of the present invention will be explained with reference to the drawings.
第１図は鋼帯表面の酸化皮膜厚みに対する鋼帯温度およ
び空気比の影響を示したグラフであり、第２図は鋼帯温
度と酸化皮膜の還元時間の関係を示すグラフであり、第
３図は本発明の実施例１に使用した横型連続焼鈍炉の縦
断面図であり、第４図は本発明の実施例２に使用した横
型連続焼鈍炉の縦断面図である。Fig. 1 is a graph showing the influence of steel strip temperature and air ratio on the oxide film thickness on the steel strip surface, Fig. 2 is a graph showing the relationship between steel strip temperature and oxide film reduction time, and Fig. 3 is a graph showing the relationship between steel strip temperature and oxide film reduction time. The figure is a vertical cross-sectional view of a horizontal continuous annealing furnace used in Example 1 of the present invention, and FIG. 4 is a vertical cross-sectional view of a horizontal continuous annealing furnace used in Example 2 of the present invention.
直火加熱を薄鋼帯の連続焼鈍に採用した場合に、鋼帯の
外観、表面性状への影響因子として直火加熱帯出口の鋼
帯温度と空気比の影響が大きいことは周知の事実である
。It is a well-known fact that when direct flame heating is used for continuous annealing of thin steel strips, the strip temperature and air ratio at the outlet of the direct flame heating zone have a large influence on the appearance and surface properties of the steel strip. be.
本発明者等は鋼帯温度と空気比の関係を調査したところ
、第１図の関係を得た。第１図から明らかなように空気
比１．０未満では直火炉内雰囲気は弱酸化性雰囲気であ
って、
Ｆｅ＋ＸＣ０２−ｊ ＦｅＯｘ ＋ＸＣ０Ｆｅ＋Ｙ Ｈ
２Ｏ−＋ ＦｅｄＹ＋Ｙ Ｈ２とからなる反応により酸
化は緩ヤかに進行するが、空気比が１，０を越えると遊
１ｉｌＩｔｏ２の存在により、
Ｆｅ＋−０□−） Ｆｅｄ２
の反応によって鋼板表面は激しく酸化される。The present inventors investigated the relationship between steel strip temperature and air ratio and found the relationship shown in FIG. 1. As is clear from Fig. 1, when the air ratio is less than 1.0, the atmosphere inside the direct-fired furnace is a weakly oxidizing atmosphere, and Fe+XC02-j FeOx +XC0Fe+Y H
Oxidation progresses slowly due to the reaction consisting of 2O−+ FedY+Y H2, but when the air ratio exceeds 1.0, the steel plate surface becomes violently oxidized due to the presence of free 1ilIto2 due to the reaction Fe+−0□−) Fed2. be done.
従って、鋼帯温度が高くなるにつれ、空気比は１．０以
下の弱酸化性雰囲気にする必要があり、特に、鋼帯温度
４００℃以上では急激に酸化するので空気比１．０以下
とする必要がある。炉後半において還元性ガスを吹付け
て実用上の時間内で還元するには酸化膜厚み約２０００
λ以下が好ましく、これ以上酸化膜厚みが大きいと還元
に時間を要し炉長が長くなる。なお、鋼帯温度の低い（
３００℃程度以下）範囲では、必ずしも弱酸化性雰囲気
にする必要はなく、熱効率向上のため、空気比１．０以
上で完全燃焼させるのが望ましい。Therefore, as the steel strip temperature increases, it is necessary to create a weakly oxidizing atmosphere with an air ratio of 1.0 or less. In particular, when the steel strip temperature exceeds 400°C, oxidation occurs rapidly, so the air ratio should be 1.0 or less. There is a need. In order to achieve reduction within a practical time by spraying reducing gas in the latter half of the furnace, the oxide film thickness must be approximately 2,000 mm.
The thickness is preferably λ or less; if the oxide film thickness is larger than this, reduction takes time and the furnace length becomes long. In addition, the steel strip temperature is low (
(approximately 300° C. or lower), it is not necessarily necessary to create a weakly oxidizing atmosphere, and in order to improve thermal efficiency, it is desirable to carry out complete combustion at an air ratio of 1.0 or higher.
しかし、弱酸化性雰囲気の直火加熱だけでは、やはり酸
化膜が生成されるので、これを解決する方法を検討し、
酸化雰囲気中で酸化させた鋼板（酸化膜厚ユｉ ｏｏｏ
入）にＨ２、炭化水素（ｅｌｋ、Ｃ２Ｈｃ・・・・・・
）、ＧＯ等を主成分とする燃料ガスを直接吹付ける実験
を実施したところ、第２図に示す結果を得た。すなわち
、第２図は前記酸化皮膜を燃料ガスにより還元するに要
する時間と鋼板温度との関係を示したもので、本実験結
果から、高温の鋼帯に還元性の燃料ガスを直接吹付けた
場合、燃料ガスが還元性の中間生成物に変化し、鋼板表
面の酸化膜を短時間で還元することが可能であることが
判明した。However, direct heating in a weakly oxidizing atmosphere will still produce an oxide film, so we investigated ways to solve this problem.
Steel plate oxidized in an oxidizing atmosphere (oxide film thickness
) into H2, hydrocarbons (elk, C2Hc...
), GO, etc., were directly sprayed, and the results shown in FIG. 2 were obtained. In other words, Figure 2 shows the relationship between the time required to reduce the oxide film with fuel gas and the temperature of the steel plate.From the results of this experiment, it was found that reducing fuel gas was directly sprayed onto the high-temperature steel strip. It has been found that in this case, the fuel gas changes into a reducing intermediate product, making it possible to reduce the oxide film on the surface of the steel sheet in a short time.
本発明者等はこれらの知見をもとに次のような非酸化焼
鈍方法を発明した。Based on these findings, the present inventors invented the following non-oxidizing annealing method.
すなわち、弱酸化性雰囲気での直火加熱により鋼帯を加
熱するとともに、鋼帯に還元性燃料ガスを直接吹付ける
ことにより、鋼帯上下面を非酸化性雰囲気ガスで層状あ
るいは薄膜状に包み、鋼帯表面酸化膜を還元し、事実上
、非酸化状態で鋼帯を加熱することが可能となった。ま
た、酸化膜が形成されても部分的に鋼帯表面を還元性ガ
スで完全に囲撓還元すると共に吹き飛ばす事により除去
する事ができる。That is, by heating the steel strip by direct flame heating in a weakly oxidizing atmosphere and by directly spraying reducing fuel gas onto the steel strip, the upper and lower surfaces of the steel strip are wrapped in a layer or thin film with non-oxidizing atmospheric gas. , it has become possible to reduce the oxide film on the surface of the steel strip and virtually heat the steel strip in a non-oxidized state. Further, even if an oxide film is formed, it can be partially removed by completely reducing the surface of the steel strip with a reducing gas and blowing it away.
なお、鋼帯に直接吹付けた還元性燃料ガスは、鋼帯の酸
化膜を還元した後、焼鈍炉入口（！ｇ帯湯温度低い方）
へ流れながら燃焼するため、鋼帯の加熱源ともなり、燃
料の無駄もなく効率よく加熱することができる。Note that the reducing fuel gas sprayed directly onto the steel strip reduces the oxide film on the steel strip, and then passes through the annealing furnace inlet (!g, where the strip temperature is lower).
Since it burns while flowing to the steel strip, it also serves as a heating source for the steel strip, allowing efficient heating without wasting fuel.
実 施 例
（実施例１）
第３図に示す横型連続焼鈍炉において、鋼帯１は横型直
火式加熱帯２で順次常温から約９００℃までバーす６で
加熱され、更に、均熱帯３で約６０秒間均熱した。加熱
帯２の前半ではバーナ６で燃焼空気比１．１以下、特に
、鋼帯温度約４００℃以上では弱酸化性雰囲気となるよ
うに空気比０．９８程度に燃焼用空気流量を調節して燃
焼させた。均熱帯３ではバーナ６（ここではサイドバー
ナ）で燃焼用空気比０．９以下で燃焼加熱する。この燃
焼では弱酸化性雰囲気であるが、鋼板表面に酸化膜は発
生するので、鋼板上面へ例えばコークス炉ガス、ＧＯ２
Ｈ２ガス等の還元性燃焼ガスを層状あるいは薄膜状に鋼
帯上面を覆うように吹付ノズル９で鋼帯全長全幅に口り
吹付ける。この還元性ガスはバーナ炎の温度より低いが
鋼帯温度と同程度となるので鋼帯を冷却することはない
。また、比重（密度）が大きく、走行鋼帯上面に乗って
拡散するので鋼帯上面には還元性雰囲気と更にその上同
側には弱酸化性雰囲気との明確な気囮を確実に形成する
ことができる。Example (Example 1) In the horizontal continuous annealing furnace shown in FIG. It was soaked for about 60 seconds. In the first half of heating zone 2, the combustion air ratio is adjusted to 1.1 or less in burner 6, and in particular, the combustion air flow rate is adjusted to about 0.98 to create a weakly oxidizing atmosphere when the steel strip temperature is about 400°C or higher. Burnt it. In the soaking zone 3, combustion heating is performed using a burner 6 (here, a side burner) at a combustion air ratio of 0.9 or less. Although this combustion creates a weakly oxidizing atmosphere, an oxide film is generated on the surface of the steel plate, so for example, coke oven gas, GO2, etc.
A reducing combustion gas such as H2 gas is sprayed from the spray nozzle 9 over the entire length and width of the steel strip so as to cover the upper surface of the steel strip in a layered or thin film form. Although the temperature of this reducing gas is lower than that of the burner flame, it is approximately the same as the temperature of the steel strip, so it does not cool the steel strip. In addition, since the specific gravity (density) is large and it spreads on the top surface of the running steel strip, it reliably forms a clear decoy of a reducing atmosphere on the top surface of the steel strip and a weakly oxidizing atmosphere on the same side. be able to.
同様に鋼帯下面へは高温に加熱された還元性ガス例えば
Ｈ２、ＣＨ４ガス等の比重（密度）の小さい還元性ガス
又はコークス炉ガス等の燃料ガスを熱交換器（図示せず
）等で加熱して鋼帯下面へ吹付ノズル９で鋼帯全幅に亘
り吹付ける。Similarly, a reducing gas heated to a high temperature with a low specific gravity (density) such as H2 or CH4 gas or a fuel gas such as coke oven gas is supplied to the lower surface of the steel strip using a heat exchanger (not shown) or the like. It is heated and sprayed onto the lower surface of the steel strip using a spray nozzle 9 over the entire width of the steel strip.
この吹付ノズル装置は例えば回転駆動装薗（図示せず）
により吹付ノズル装置を通板鋼板レベルに追従させて吹
付ノズルを可変とすることによって、鋼帯上下面を還元
性ガスで確実に覆うように配置する。この還元性ガスの
吹付けは酸化膜の還元と酸化防止を兼ね、また、発生し
た酸化膜の飛散除去も兼ねることができる。この吹付け
は鋼帯全長全幅に亘って行なってもよく、また、一定長
さ区間のみを適宜個所に亘って実施してもよいが、要は
第２図の鋼板温度と還元時間との関係に従って完全に還
元できる吹付時間約３０秒を保持するように設定する。This spray nozzle device is, for example, a rotary drive device (not shown).
By making the spray nozzle device follow the level of the passed steel plate and making the spray nozzle variable, the upper and lower surfaces of the steel strip are arranged to be reliably covered with reducing gas. This spraying of reducing gas serves both to reduce and prevent oxidation of the oxide film, and also to scatter and remove the generated oxide film. This spraying may be performed over the entire length and width of the steel strip, or may be performed only over a certain length section as appropriate, but the key point is that the relationship between the steel sheet temperature and reduction time shown in Figure 2 The spraying time is set to about 30 seconds for complete reduction.
このように還元性雰囲気で還元した後、鋼帯を冷却帯４
においてＮ２ガス雰囲気中で常法の冷却方式で常温付近
まで冷却する。このようにして得られた焼鈍鋼帯はテン
パーカラー、煤付き、ピックアップ疵はなく、表面性状
は第１表に示す如く、輻射管式バーナ、とくに、ラジア
ントチューブバーナの間接加熱方式により製造された標
準製品と比べ、はぼ同等のものが得られた。After being reduced in a reducing atmosphere in this way, the steel strip is placed in a cooling zone 4.
Then, it is cooled down to around room temperature using a conventional cooling method in a N2 gas atmosphere. The annealed steel strip thus obtained had no temper color, no soot, no pick-up defects, and the surface properties were as shown in Table 1.It was manufactured using the indirect heating method using a radiant tube burner, especially a radiant tube burner. Compared to the standard product, a product that was almost equivalent was obtained.
第 １ 表 註 化成処理性、塗膜密着性および 塗装耐食性は１０点法で評価した。Table 1 Note: Chemical conversion treatment properties, coating adhesion and Paint corrosion resistance was evaluated using a 10-point scale.
（実施例２）
第４図に示す横型連続焼鈍炉において、鋼帯１は直火式
加熱帯と均熱帯を兼用する加熱帯２へ順次炉入側より入
り常温から約８５０°Ｃまで加熱し、約３０秒間均熱後
、冷却帯４においてＮ２雰囲気中で常法の冷却方式で冷
却する。(Example 2) In the horizontal continuous annealing furnace shown in Fig. 4, the steel strip 1 is sequentially entered from the furnace entry side into the heating zone 2, which serves as both the direct-fired heating zone and the soaking zone, and is heated from room temperature to approximately 850°C. After soaking for about 30 seconds, it is cooled in a N2 atmosphere in a cooling zone 4 by a conventional cooling method.
鋼帯の加熱は加熱帯２の前半ではサイドバーナ６で、ま
た、後半ではサイドバーす６、ルーフバーナ７および炉
底バーナ８で構成し、とくに、ルーフバーナ７および炉
底バーナ８を主体で加熱する。還元性ガスを吹付ける吹
付ノズル装置９は走行する鋼帯レベルに適合させ、駆動
装置（図示せず）により上下動させて鋼帯レベルに追従
するよう構成し、鋼帯の上下面及び全幅に亘り適宜箇所
の鋼帯面に還元性ガスを吹付ける配置としている。鋼帯
の上下面に吹付ける還元性ガスは前記実施例１と同種類
のガスを使用した。The steel strip is heated by a side burner 6 in the first half of the heating zone 2, and by a side burner 6, a roof burner 7, and a hearth bottom burner 8 in the second half. . The spray nozzle device 9 that sprays reducing gas is adapted to the level of the steel strip on which it runs, and is configured to be moved up and down by a drive device (not shown) to follow the level of the steel strip. The arrangement is such that reducing gas is sprayed onto the steel strip surface at appropriate locations. The same type of reducing gas as in Example 1 was used as the reducing gas sprayed onto the upper and lower surfaces of the steel strip.
本実施例においては、加熱帯および均熱帯の兼用炉であ
り、加熱の主体はルーツバ〜す７および炉底バーナ８と
して直接バーナ炎が鋼帯表面に触れないように加熱し、
還元性ガスを鋼帯表面を被覆するよう吹付け、鋼帯温度
４００〜５００℃以上の区域で酸化膜を還元した。鋼帯
温度４００℃以下の区域では還元用燃料ガスの燃焼をも
考慮して、弱酸性雰囲気（空気比１．０〜１．１程度）
となるよう燃焼用空気流量を調節した。In this embodiment, the furnace is used as both a heating zone and a soaking zone, and the heating is mainly carried out by the roots bath 7 and the bottom burner 8, which heat the steel strip so that the burner flame does not directly touch the surface of the steel strip.
A reducing gas was sprayed to cover the surface of the steel strip, and the oxide film was reduced in an area where the steel strip temperature was 400 to 500°C or higher. In areas where the steel strip temperature is below 400℃, a weakly acidic atmosphere (air ratio of about 1.0 to 1.1) is used, taking into account the combustion of the reducing fuel gas.
The combustion air flow rate was adjusted so that
このようにして製造された製品は前記実施例１と同等の
表面性状のものが得られた。The product manufactured in this manner had a surface quality equivalent to that of Example 1.
なお、実施例１および実施例２において、搬送ローラ１
１の代りに第３図、第４図中の点線に示す如く、フロー
タ方式のフローティングノズル１０や同ノズルに別途付
設した吹付ノズルより鋼帯面へ還元性ガスを吹付けても
よく、前記吹付ノズル装置９方式と本方式とを併用して
吹付けてもよいものである。In addition, in Example 1 and Example 2, the conveyance roller 1
Instead of 1, as shown by the dotted lines in FIGS. 3 and 4, reducing gas may be sprayed onto the steel strip surface from a floater type floating nozzle 10 or a spray nozzle separately attached to the floater type floating nozzle 10. The nozzle device 9 method and this method may be used together for spraying.
〈発明の効果〉
以−［説明したように、本発明は、横型連続焼鈍炉によ
って鋼帯を直火加熱する際に、鋼帯温度が４００℃以上
では燃焼用空気比を１．０未満として燃焼させて鋼帯を
加熱すると共に、還元性ガスを前記鋼帯の上下面を薄膜
状に被覆するように吹付け、鋼帯表面の酸化膜を還元し
て加熱することを特徴とする鋼帯の連続焼鈍方法であっ
て、本発明方法によれば、薄鋼帯の連続焼鈍にあたり、
高品質の製品を大量に生産する口とができ、とくに、従
来のように、直火加熱帯の後に、還元雰囲気（Ｈ２等）
から成る還元帯を設ける必要もなく、また、還元用に使
用した燃料ガスは加熱源としても使用でき全く無駄がな
いので焼鈍工程にもたらす利益が極めて大である。<Effects of the Invention> [As explained above, the present invention has the advantage that when the steel strip is directly heated in a horizontal continuous annealing furnace, the combustion air ratio is set to less than 1.0 when the steel strip temperature is 400°C or higher. A steel strip characterized in that the steel strip is heated by combustion, and a reducing gas is sprayed so as to cover the upper and lower surfaces of the steel strip in a thin film, thereby reducing the oxide film on the surface of the steel strip and heating the steel strip. According to the method of the present invention, in continuous annealing of a thin steel strip,
It is possible to produce high-quality products in large quantities, especially in a reducing atmosphere (H2 etc.) after the direct heating zone as in the past.
There is no need to provide a reduction zone consisting of 100%, and the fuel gas used for reduction can also be used as a heating source, so there is no waste at all, so the benefits brought to the annealing process are extremely large.
第１図は鋼帯表面の酸化皮膜厚みに対する鋼帯温度およ
び空気比の影響を示したグラフ、第２図は鋼帯温度と酸
化皮膜の還元時間の関係を示すグラフ、第３図は本発明
の実施例１に使用した横型連続焼鈍炉の縦断面図、第４
図は本発明の実施例２に使用した横型連続焼鈍炉の縦断
面図である。
符号１・・・・・・鋼帯
２・・・・・・焼鈍炉の加熱帯
３・・・・・・焼鈍炉の還元帯
４・・・・・・冷却帯
６・・・・・・サイドバーナ
７・・・・・・ルーフバーナ
８・・・・・・炉底バーナ
９・・・・・・還元ガス吹付ノズル装置１０・・・・・
・フローティングノズル１１・・・・・・ローラ
第１図
第２図
側ｎし桧皮Fig. 1 is a graph showing the influence of steel strip temperature and air ratio on the oxide film thickness on the steel strip surface, Fig. 2 is a graph showing the relationship between steel strip temperature and oxide film reduction time, and Fig. 3 is a graph showing the effect of the present invention. Vertical cross-sectional view of the horizontal continuous annealing furnace used in Example 1, No. 4
The figure is a longitudinal sectional view of a horizontal continuous annealing furnace used in Example 2 of the present invention. Code 1...Steel strip 2...Heating zone 3 of the annealing furnace...Reduction zone 4 of the annealing furnace...Cooling zone 6... Side burner 7... Roof burner 8... Furnace bottom burner 9... Reducing gas spray nozzle device 10...
・Floating nozzle 11...roller Figure 1 Figure 2 side n cypress bark
Claims (1)
温度が４００℃以上では燃焼用空気比を１．０未満とし
て燃焼させて鋼帯を加熱すると共に、還元性ガスを前記
鋼帯の上下面を薄膜状に被覆するように吹付け、鋼帯表
面の酸化膜を還元して加熱することを特徴とする鋼帯の
連続焼鈍方法。When directly heating a steel strip in a horizontal continuous annealing furnace, if the steel strip temperature is 400°C or higher, the combustion air ratio is set to less than 1.0 to heat the steel strip, and at the same time, the reducing gas is A continuous annealing method for a steel strip, characterized by spraying the top and bottom surfaces of the steel strip in a thin film to reduce the oxide film on the surface of the steel strip and heating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27775286A JPS63130718A (en) | 1986-11-20 | 1986-11-20 | Continuous annealing method for steel strip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27775286A JPS63130718A (en) | 1986-11-20 | 1986-11-20 | Continuous annealing method for steel strip |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63130718A true JPS63130718A (en) | 1988-06-02 |
Family
ID=17587837
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27775286A Pending JPS63130718A (en) | 1986-11-20 | 1986-11-20 | Continuous annealing method for steel strip |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63130718A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101150375B1 (en) | 2008-09-30 | 2012-06-11 | 주식회사 에스에이씨 | Bright annealin gfurnace including heating furnace and bright annealing method with the annealing furnace |
-
1986
- 1986-11-20 JP JP27775286A patent/JPS63130718A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101150375B1 (en) | 2008-09-30 | 2012-06-11 | 주식회사 에스에이씨 | Bright annealin gfurnace including heating furnace and bright annealing method with the annealing furnace |
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