JP2964905B2 - Method and apparatus for cooling hot-dip coated steel sheet - Google Patents
Method and apparatus for cooling hot-dip coated steel sheetInfo
- Publication number
- JP2964905B2 JP2964905B2 JP6785795A JP6785795A JP2964905B2 JP 2964905 B2 JP2964905 B2 JP 2964905B2 JP 6785795 A JP6785795 A JP 6785795A JP 6785795 A JP6785795 A JP 6785795A JP 2964905 B2 JP2964905 B2 JP 2964905B2
- Authority
- JP
- Japan
- Prior art keywords
- cooling
- steel sheet
- hot
- coated steel
- dip coated
- 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 - Fee Related
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- Coating With Molten Metal (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、溶融めっき鋼板の冷却
方法および装置、特に溶融めっき直後に鋼板を冷却する
方法および装置に関し、より詳しくは、溶融亜鉛系めっ
き鋼板の板長手方向、あるいはさらに板幅方向および板
厚方向におけるめっき皮膜特性、即ち、スパングル粒径
等を均一に制御することが可能であって、且つ溶融めっ
き鋼板の効率的な冷却を可能とする、溶融めっき鋼板の
冷却方法および装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cooling hot-dip coated steel sheets, and more particularly to a method and apparatus for cooling steel sheets immediately after hot-dip coating. A method for cooling a hot-dip coated steel sheet, capable of uniformly controlling plating film properties in the sheet width direction and the sheet thickness direction, that is, spangle diameter and the like, and enabling efficient cooling of the hot-dip coated steel sheet. And equipment.
【０００２】[0002]
【従来の技術】溶融めっき鋼板、とりわけ55wt％Al−Zn
合金めっき鋼板は、Alめっき鋼板が有する高耐食性およ
び耐熱性と溶融亜鉛めっき鋼板が有する犠牲防食性とを
合わせ持つため、溶融亜鉛めっき鋼板やAlめっき鋼板に
替わって建材、家電、自動車等の分野での使用量が増え
つつある。この55wt％Al−Zn合金めっき鋼板は独特な銀
白色の美麗な外観を有しており、建材用途ではこの外観
を活かしてめっき表面をクリヤ皮膜（１〜３g/m2）で覆
って使用することが多い。2. Description of the Related Art Hot-dip coated steel sheets, especially 55 wt% Al-Zn
Alloy-coated steel sheets combine the high corrosion resistance and heat resistance of Al-coated steel sheets with the sacrificial corrosion resistance of hot-dip galvanized steel sheets. Usage in the country is increasing. The 55 wt% Al-Zn alloy coated steel sheet has a beautiful appearance unique silvery white, the construction materials used to cover the plated surface by utilizing this look in clear coatings (1~3g / m 2) Often.
【０００３】溶融めっき後の鋼板では、スパングルが進
行する。スパングル粒径が粗大化するとスパングル粒径
の不均一化が促進される。そのため最近では、スパング
ル粒径幅方向および長手方向の均一化、各板厚間のスパ
ングル粒径の差を小さくすることが望まれている。[0003] In steel sheets after hot-dip plating, spangles progress. When the spangle particle size is coarsened, the spangle particle size becomes uneven. Therefore, recently, it has been desired to make the spangle particle size uniform in the width direction and the longitudinal direction and to reduce the difference in spangle particle size between the sheet thicknesses.
【０００４】特に55wt％Al−Zn合金めっき鋼板の美麗な
銀白色の外観を利用する場合、その外観が重要であるた
めスパングル粒径の均一性が求められ、特にパネルとし
て使用する場合、その要求レベルは高い。さらに、異な
る板厚の鋼板 (例：0.27〜2.3 mm) を用いる場合にも、
板厚によらず一定のスパングル粒径であることが要求さ
れる。[0004] In particular, when utilizing the beautiful silver-white appearance of a 55 wt% Al-Zn alloy plated steel sheet, the appearance is important and uniformity of the spangle particle size is required. The level is high. Furthermore, when using steel plates of different thicknesses (eg 0.27-2.3 mm)
It is required to have a constant spangle particle size regardless of the plate thickness.
【０００５】通常、溶融めっき後の鋼板表面は、板幅方
向において凸形状の温度分布（鋼板中央部で温度が高く
鋼板両端で温度が低い）を有する。スパングルの成長は
溶融めっき鋼板の冷却速度に影響を受けるため、従来に
あっては、いずれも溶融めっき後、バーナ加熱、クーラ
ボックスなどを経て鋼板全体を均一温度としてから、微
細化装置において微細化薬剤あるいは冷却水の散布を行
って冷却を行っている。つまり、冷却の準備段階で凝固
直前にまで持ち来たしてから少なくともその温度におい
て全体を均一温度としてから一挙に冷却をしようとする
のである。Usually, the surface of the steel sheet after hot-dip plating has a convex temperature distribution in the sheet width direction (the temperature is high at the center of the steel sheet and low at both ends of the steel sheet). Since spangle growth is affected by the cooling rate of hot-dip coated steel sheet, conventionally, after hot-dip coating, the entire steel sheet is heated to a uniform temperature via a burner heater, cooler box, etc. Cooling is performed by spraying chemicals or cooling water. In other words, after being brought to just before solidification in the preparation stage for cooling, the entire body is made uniform at least at that temperature and then cooled at once.
【０００６】しかしながら、かかる従来技術では、溶融
めっき鋼板の目付量を調整してから、バーナ加熱とクー
ラボックスによる冷却を行わなければならず、そのため
の時間、スペース、そして設備は不可欠であった。However, in the prior art, the burner heating and the cooling by the cooler box must be performed after adjusting the basis weight of the hot-dip coated steel sheet, and the time, space, and equipment for that are indispensable.
【０００７】[0007]
【発明が解決しようとする課題】かくして、本発明の目
的は、上述の従来技術の問題を解消し、溶融めっき鋼板
製造におけるめっき皮膜特性が良好、即ち、スパングル
粒径が板長手方向および板幅方向の何れにおいても均一
である溶融めっき鋼板の製造が可能であり、さらに効率
的な冷却が可能である溶融めっき鋼板の冷却方法および
装置を提供することである。Thus, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide good plating film characteristics in the production of hot-dip coated steel sheets, that is, the spangle particle size is reduced in the plate longitudinal direction and the plate width. An object of the present invention is to provide a method and an apparatus for cooling a hot-dip coated steel sheet that can manufacture a hot-dip coated steel sheet that is uniform in any direction and that can perform more efficient cooling.
【０００８】[0008]
【課題を解決するための手段】本発明者らは、従来のよ
うにめっき終了後に急冷処理に対する準備段階として温
度調整を行うことなく、直接急冷することの経済性に着
目し、55wt％Al−Zn合金めっき鋼板のスパングル粒径と
めっき直後の冷却速度の関係について検討を行った。The inventors of the present invention focused on the economics of directly quenching without performing temperature adjustment as a preparation stage for quenching after completion of plating, as in the prior art. The relationship between the spangle particle size of Zn alloy plated steel sheet and the cooling rate immediately after plating was studied.
【０００９】図１に示すように、めっき直後の鋼板の冷
却速度が55wt％Al−Zn合金めっき鋼板のスパングル粒径
に与える影響は非常に大きい。このことは従来のように
スパングルの微細化、均一化のために薬剤を噴霧するこ
となく、めっき直後であれば、単に冷却速度の制御によ
ってスパングル粒径を制御できる可能性を示している。As shown in FIG. 1, the effect of the cooling rate of the steel sheet immediately after plating on the spangle particle size of the 55 wt% Al-Zn alloy coated steel sheet is very large. This shows the possibility that the spangle particle size can be controlled simply by controlling the cooling rate immediately after plating without spraying a chemical for miniaturizing and homogenizing the spangle as in the prior art.
【００１０】図１の結果は、Al−Zn合金めっき直後の鋼
板を冷却した際の関係であり、この「めっき直後」と
は、めっき皮膜が溶融または半溶融状態であって１次デ
ンドライトが析出する直前までの時期を指す。スパング
ルが成長するのはめっき皮膜が完全固化する前であり、
スパングル粒径を制御する時期はめっき表層に１次デン
ドライトが析出 (めっき皮膜が固化) する前でなければ
ならない。The results in FIG. 1 are obtained when the steel sheet immediately after Al-Zn alloy plating is cooled, and the term "immediately after plating" means that the plating film is in a molten or semi-molten state and primary dendrite is deposited. It indicates the time until just before. Spangles grow before the plating film is completely solidified,
The time to control the spangle particle size must be before the primary dendrite is deposited on the plating surface layer (the plating film solidifies).
【００１１】図１より、めっき直後の冷却速度が速いほ
ど、めっき皮膜表面に現れるスパングルの粒径が小さく
なることがわかる。特にスパングル粒径に対しては、冷
却開始時の冷却速度の影響が大きいことがわかる。本発
明者らは、さらに、後述する図２に示す垂直冷却帯を有
する冷却装置を用い、冷却パターンを変えて目付け量調
整後の溶融めっき鋼板の冷却を行った。FIG. 1 shows that the faster the cooling rate immediately after plating, the smaller the particle size of spangles appearing on the surface of the plating film. In particular, it can be seen that the cooling speed at the start of cooling has a great effect on the spangle particle size. The present inventors further cooled the hot-dip coated steel sheet after adjusting the basis weight by changing the cooling pattern using a cooling device having a vertical cooling zone shown in FIG. 2 described below.
【００１２】ここで冷却パターンとは冷却装置長手方向
においての冷却速度の変化の様子を指し、次の２つの冷
却パターンで行った。冷却パターン以外の操業条件 (冷
却媒体、装置全体の冷却能力、鋼板の厚み・幅、等)
は、いずれの場合もともに同一とした。Here, the cooling pattern refers to a state of a change in the cooling rate in the longitudinal direction of the cooling device, and the cooling is performed in the following two cooling patterns. Operating conditions other than the cooling pattern (cooling medium, cooling capacity of the entire system, thickness and width of steel sheet, etc.)
Were the same in each case.
【００１３】冷却パターンＡ： 冷却装置全域において
鋼板の冷却速度一定 冷却パターンＢ： 初期：急速冷却→中期〜後期：低速
冷却 これらの結果から、以下のような知見が得られた。Cooling pattern A: Constant cooling rate of steel sheet throughout cooling device Cooling pattern B: Initial: rapid cooling → middle to late: slow cooling From these results, the following findings were obtained.
【００１４】冷却装置入側と冷却装置出側の溶融めっき
鋼板の温度変化 (ΔＴ＝ＴI −ＴO) はＡ、Ｂともほぼ
同じであったが、得られた溶融めっき鋼板のめっき皮膜
特性はＡに比べてＢの方がスパングルの粒径が小さく且
つ均一であった。The temperature change (ΔT = T I -T O ) of the hot-dip coated steel sheet on the cooling device inlet side and the cooling device outgoing side was almost the same for both A and B, but the plating film characteristics of the obtained hot-dip coated steel sheet In B, the grain size of spangles was smaller and more uniform in B than in A.
【００１５】上記知見より、効率的な溶融めっき鋼板の
冷却を行うためには、冷却パターンを急速冷却→低速冷
却とすればよいことが分かる。また、スパングル粒径が
板長手方向および板幅方向の何れにおいても均一とする
ためには、鋼板の板長手方向ばかりでなく、板幅方向の
冷却速度を上述のように制御すればよい。From the above knowledge, it can be seen that the cooling pattern should be changed from rapid cooling to low-speed cooling in order to efficiently cool the hot-dip coated steel sheet. Further, in order to make the spangle particle size uniform in both the plate longitudinal direction and the plate width direction, the cooling rate in the plate width direction as well as the plate longitudinal direction of the steel plate may be controlled as described above.
【００１６】そこで、本発明者らは、溶融金属めっき鋼
板を目付け量調整後に直ちに急冷することにより、スパ
ングル粒径が制御可能であることを知り、またそのとき
の冷却速度が鋼板の長手方向ばかりなく、幅方向におい
ても変更できるようにすれば鋼板全体のスパングル制御
が均一にできることを知り、本発明を完成した。Therefore, the present inventors have found that the spangle diameter can be controlled by immediately cooling the hot-dip coated steel sheet after adjusting the basis weight, and the cooling rate at that time is limited only to the longitudinal direction of the steel sheet. Instead, it was found that the spangle control of the entire steel plate could be made uniform if it could be changed in the width direction, and the present invention was completed.
【００１７】ここに、本発明は、もっとも広義には、溶
融めっき浴から引き上げられた溶融めっき鋼板の目付け
量を調整してから直ちに冷却装置において溶融めっき鋼
板を冷却し、該冷却装置の鋼板走行方向に沿って冷却速
度を制御するとともに、該冷却装置による冷却開始時、
例えば該冷却装置の入口において溶融めっき鋼板を急冷
することによってスパングル特性を制御することを特徴
とする溶融めっき鋼板の冷却方法である。Here, in the broadest sense, the present invention is to cool the hot-dip coated steel sheet in a cooling device immediately after adjusting the basis weight of the hot-dip coated steel sheet pulled up from the hot-dip coating bath, While controlling the cooling rate along the direction, at the start of cooling by the cooling device,
For example, there is provided a method for cooling a hot-dip coated steel sheet, wherein spangle characteristics are controlled by rapidly cooling the hot-dip coated steel sheet at an inlet of the cooling device.
【００１８】さらに別の面からは、本発明は、溶融めっ
き鋼板の目付け量調整手段に引き続いて設ける冷却装置
であって、鋼板の幅方向に延びた平行スリットノズルを
長手方向に、つまり鋼板の走行方向に沿って多段に設
け、それらのスリットノズル列の全体を複数の冷却ゾー
ンに区画するとともに、幅方向においてもスリットノズ
ルの背後に仕切り板を設けることで複数の冷却セクショ
ンに区画し、これらの各冷却ゾーンおよび必要により冷
却セクションが独立して冷却媒の流速を制御できるよう
に構成したことを特徴とする溶融めっき鋼板のスパング
ル特性を制御する冷却装置である。From another aspect, the present invention relates to a cooling device provided subsequent to a basis weight adjusting means for a hot-dip coated steel sheet, wherein a parallel slit nozzle extending in a width direction of the steel sheet is provided in a longitudinal direction, that is, the steel sheet is provided with a parallel slit nozzle. Provided in multiple stages along the running direction, the entirety of the slit nozzle row is divided into a plurality of cooling zones, and also in the width direction, a partition plate is provided behind the slit nozzle to divide the cooling nozzle into a plurality of cooling sections. Supangu molten plated steel sheet by the cooling zone and the need for and characterized by being configured to be able to control the flow rate of the cooling section is independently cooled medium
This is a cooling device for controlling the cooling characteristics .
【００１９】本発明の好適態様によれば、複数の前記冷
却ゾーンを冷却媒流路で連通させ、最下流側の冷却ゾー
ンに冷却媒導入口を設けてもよい。本発明のさらに別の
好適態様にあっては、上記冷却装置全体をめっき鋼板の
進行方向に移動自在に設置してもよい。According to a preferred aspect of the present invention, the plurality of cooling zones may be communicated with each other through a cooling medium flow path, and a cooling medium introduction port may be provided in a cooling zone on the most downstream side. In still another preferred embodiment of the present invention, the entire cooling device may be installed movably in the traveling direction of the plated steel sheet.
【００２０】[0020]
【作用】図２に本発明にかかる溶融めっき鋼板の製造装
置の概略図を示す。一般に、所定の熱処理を施された被
めっき鋼板は、溶融金属めっき浴１に通板された後、シ
ンクロール２を周回して垂直に引き上げられ、ワイピン
グノズル３で溶融金属の目付量を調整して所定のめっき
付着量に調整される。その後、この溶融状態あるいは半
溶融状態にある未凝固のめっき皮膜を有する鋼板は、直
ちに、冷却装置に通される。冷却装置は背後の冷却媒体
流路４と冷却媒体の導入口７そして冷却媒体の吹出口８
から構成される。導入口７から供給される冷却媒体は冷
却媒体流路４を経て吹出口８から鋼板５に向かって噴射
される。この冷却媒体気体、気体＋液体、気体＋金属粉
末により鋼板表面は急冷され、これにより溶融めっき皮
膜表面のスパングルの成長が抑制され、均一化するので
ある。FIG. 2 is a schematic view of a hot-dip coated steel sheet manufacturing apparatus according to the present invention. In general, a steel sheet to be plated subjected to a predetermined heat treatment is passed through a molten metal plating bath 1 and then pulled vertically around a sink roll 2 to adjust the basis weight of the molten metal with a wiping nozzle 3. Is adjusted to a predetermined plating adhesion amount. Thereafter, the steel sheet having the unsolidified plating film in the molten or semi-molten state is immediately passed through a cooling device. The cooling device comprises a cooling medium flow path 4 at the back, a cooling medium inlet 7 and a cooling medium outlet 8.
Consists of The cooling medium supplied from the inlet 7 is injected toward the steel plate 5 from the outlet 8 through the cooling medium flow path 4. The surface of the steel sheet is rapidly cooled by the cooling medium gas, the gas + liquid, and the gas + metal powder, whereby the growth of spangles on the surface of the hot-dip coating is suppressed and uniformized.
【００２１】図３はスリットノズルから構成される吹出
口８の鋼板側から見たときの平面図であり、図中各スリ
ットノズルは鋼板の幅方向に伸びて多段に設けられてお
り、その背後に冷却媒体流路４が設けられている。FIG. 3 is a plan view when viewed from the steel plate side of the outlet 8 constituted by slit nozzles. In the figure, each slit nozzle extends in the width direction of the steel plate and is provided in multiple stages. Is provided with a cooling medium flow path 4.
【００２２】このスリットノズルに代えて単に吹出しノ
ズル (図示せず) としてもよいが、ある程度の流量を確
保して、装置全体を簡便にするという点ではスリットノ
ズルが好ましい。Instead of the slit nozzle, a blowing nozzle (not shown) may be used, but a slit nozzle is preferable in that a certain flow rate is secured and the whole apparatus is simplified.
【００２３】ここに、冷却装置としては、(イ) 溶融めっ
き鋼板をめっき直後の冷却過程の初期で急速冷却するこ
と、および(ロ) 冷却装置の持っている設備上の冷却能力
を最大限に発揮できるようにすることが重要である。Here, the cooling device is (a) to rapidly cool the hot-dip coated steel sheet in the initial stage of the cooling process immediately after plating, and (b) to maximize the cooling capacity of the equipment provided by the cooling device. It is important to be able to demonstrate.
【００２４】本発明によれば、したがって、冷却装置の
長手方向において冷却媒体吐出量を制御可能な冷却装置
が実現される。具体的には冷却装置の長手方向の冷却媒
体流路内に設けられたダンパ等により、各冷却ゾーン毎
に鋼板の走行方向の冷却媒体吐出量を変えられる。この
ため、溶融めっき鋼板の冷却パターンを、急速冷却→低
速冷却とすることができ、上記(イ) を満足する。According to the present invention, therefore, a cooling device capable of controlling the discharge amount of the cooling medium in the longitudinal direction of the cooling device is realized. Specifically, the discharge amount of the cooling medium in the running direction of the steel sheet can be changed for each cooling zone by a damper or the like provided in the cooling medium flow path in the longitudinal direction of the cooling device. For this reason, the cooling pattern of the hot-dip coated steel sheet can be changed from rapid cooling to low-speed cooling, which satisfies the condition (1).
【００２５】また、冷却装置全体の総冷却能力が同じで
あれば冷却パターンに関わらず冷却装置入側と出側の温
度差ΔＴは変わらないので、冷却装置の長手方向におい
て冷却媒体を効率的に使用しており、上記(ロ) を満足す
る。Further, if the total cooling capacity of the entire cooling device is the same, the temperature difference ΔT between the inlet and the outlet of the cooling device does not change regardless of the cooling pattern. It satisfies (b) above.
【００２６】さらに、本発明によれば、鋼板幅方向にお
いて冷却媒体吐出量を制御可能な冷却装置が実現され
る。具体的には鋼板幅方向の冷却媒体吐出量を制御する
ために、冷却媒流路、つまり冷却媒体流路内に設けられ
たダンパと仕切り板等により、鋼板の板幅方向に設けた
各冷却セクション毎に冷却媒体吐出量を変えられる。こ
のため、幅方向での均一冷却が可能となるため、上記
(ロ) を満足する。Further, according to the present invention, a cooling device capable of controlling the discharge amount of the cooling medium in the width direction of the steel sheet is realized. Specifically, in order to control the discharge amount of the cooling medium in the width direction of the steel sheet, each cooling medium provided in the width direction of the steel sheet by a cooling medium flow path, that is, a damper and a partition plate provided in the cooling medium flow path. The cooling medium discharge amount can be changed for each section. For this reason, uniform cooling in the width direction becomes possible,
(B) is satisfied.
【００２７】かくして本発明によれば、従来のようにめ
っき付着量制御後に加熱バーナあるいはクーラボックス
をさらに設ける必要をなくし、装置全体が簡便になり、
それにも係わらず冷却装置の長手方向および幅方向にお
いて冷却媒体吐出量を制御可能となる非常に優れた冷却
装置が得られる。板長手方向および板幅方向の冷却媒体
吐出量を制御する機能を有する設備は特に制限されない
が、ダンパ、スリットギャップの可変制御等が挙げられ
る。Thus, according to the present invention, it is not necessary to additionally provide a heating burner or a cooler box after controlling the amount of plating as in the prior art, and the entire apparatus is simplified.
Nevertheless, it is possible to obtain a very excellent cooling device that can control the discharge amount of the cooling medium in the longitudinal direction and the width direction of the cooling device. The equipment having a function of controlling the cooling medium discharge amount in the plate longitudinal direction and the plate width direction is not particularly limited, and examples thereof include a damper and a variable control of a slit gap.
【００２８】さらに、本発明の冷却装置を上下方向に移
動可能とすれば、冷却装置と溶融めっき浴との距離を変
化させて溶融めっき鋼板の冷却開始温度を調節すること
ができ、スパングル粒径を所望の大きさに均一にするこ
とができる。さらに各板厚に対応して冷却開始温度を調
節することにより、各種板厚間のスパングル粒径差を解
消することができる。Further, if the cooling device of the present invention can be moved in the vertical direction, the cooling start temperature of the hot-dip coated steel sheet can be adjusted by changing the distance between the cooling device and the hot-dip bath, and the spangle particle size can be adjusted. Can be made uniform to a desired size. Further, by adjusting the cooling start temperature in accordance with each plate thickness, it is possible to eliminate a spangle particle size difference between various plate thicknesses.
【００２９】[0029]
【実施例】以下、本発明に係る溶融めっき鋼板の冷却装
置の例として冷却媒体吐出量の調整にダンパを用いた場
合を、図面に基づいて具体的に説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a case where a damper is used for adjusting a discharge amount of a cooling medium as an example of a cooling apparatus for a hot-dip coated steel sheet according to the present invention will be specifically described with reference to the drawings.
【００３０】実施例１ 図４a および図４b は、冷却装置長手方向の冷却媒体吐
出量を調整するために冷却媒体流路４内にダンパを２個
設けた冷却装置である。本例では冷却媒体流路４への冷
却媒体導入口７を下流側、つまり冷却装置の入口側に設
けてある。Embodiment 1 FIGS. 4A and 4B show a cooling device in which two dampers are provided in the cooling medium passage 4 in order to adjust the discharge amount of the cooling medium in the longitudinal direction of the cooling device. In this example, the cooling medium inlet 7 to the cooling medium flow path 4 is provided on the downstream side, that is, on the inlet side of the cooling device.
【００３１】冷却媒体は、送風装置６によってダクトか
ら冷却媒体流路４の下部に設けられた導入口７に送ら
れ、冷却媒体流路４の冷却媒体吹き出し口８から溶融め
っき鋼板５に対して噴射される。この際、冷却媒体流路
４に設けられたダンパ９a および９b の開度によって冷
却装置の長手方向における冷却媒体の吐出量を調整でき
る。The cooling medium is sent from a duct by a blower 6 to an inlet 7 provided below the cooling medium flow path 4, and from a cooling medium outlet 8 of the cooling medium flow path 4 to the hot-dip coated steel sheet 5. It is injected. At this time, the discharge amount of the cooling medium in the longitudinal direction of the cooling device can be adjusted by the openings of the dampers 9a and 9b provided in the cooling medium flow path 4.
【００３２】図４a 、４ｂにおいて、冷却ゾーンＩ、冷
却ゾーンII、冷却ゾーンIII の順に、冷却媒体吐出量は
少なくなり溶融めっき鋼板の冷却速度が小さくなる。ダ
ンパの開度が低いほどダンパの下側の冷却媒体吐出量を
多く、即ち、溶融めっき鋼板の冷却速度を速くできるの
で、ダンパの開度は所望の冷却速度となるように調整す
ればよい。4A and 4B, in the order of the cooling zone I, the cooling zone II, and the cooling zone III, the discharge amount of the cooling medium decreases and the cooling rate of the hot-dip coated steel sheet decreases. As the opening degree of the damper is lower, the discharge amount of the cooling medium below the damper can be increased, that is, the cooling rate of the hot-dip coated steel sheet can be increased. Therefore, the opening degree of the damper may be adjusted to a desired cooling rate.
【００３３】図４a のような冷却装置により溶融めっき
鋼板を冷却すると冷却過程初期の急速冷却ができるた
め、スパングル粒径を小さく且つ均一にすることがで
き、しかも鋼板および溶融金属めっき層、例えば亜鉛め
っき層の潜熱を除去しめっき層の再溶融を防ぐことがで
きる。従って、得られる溶融めっき鋼板のスパングル粒
径は小さく且つ均一である。When the hot-dip coated steel sheet is cooled by a cooling apparatus as shown in FIG. 4A, rapid cooling can be performed at an early stage of the cooling process, so that the spangle particle size can be made small and uniform. The latent heat of the plating layer can be removed and the remelting of the plating layer can be prevented. Therefore, the spangle diameter of the obtained hot-dip coated steel sheet is small and uniform.
【００３４】次に、冷却装置の幅方向の冷却媒体吐出量
を調整するために冷却媒体流路４ではなく導入口７内に
ダンパを設けた冷却装置を図５a および図５b に示す。Next, FIGS. 5A and 5B show a cooling device in which a damper is provided in the inlet 7 instead of the cooling medium flow path 4 in order to adjust the discharge amount of the cooling medium in the width direction of the cooling device.
【００３５】この冷却装置は、セクション区分板11によ
って冷却装置幅方向を３つの冷却セクションＡ、Ｂおよ
びＣに分割し、冷却媒体流路４内の冷却セクションＡお
よびＣにそれぞれダンパ10を設けられている。各冷却セ
クションは、区分板11によって完全に分割されており、
各冷却セクションの冷却媒体吐出量は独立に制御でき
る。各ダンパ10の開度を調整し各冷却セクションＡない
しＣへの冷却媒体の吐出を調整できる。In this cooling device, the width direction of the cooling device is divided into three cooling sections A, B, and C by a section dividing plate 11, and dampers 10 are provided in the cooling sections A and C in the cooling medium flow path 4, respectively. ing. Each cooling section is completely divided by a partition plate 11,
The cooling medium discharge amount of each cooling section can be controlled independently. By adjusting the opening of each damper 10, the discharge of the cooling medium to each of the cooling sections A to C can be adjusted.
【００３６】冷却媒体は送風装置６からダクトに送りこ
まれ、ダクト内の下部に設置された導入口７を経てダン
パ10を通って冷却媒体流路４に送りこまれ、冷却媒体吹
き出し口８から鋼板５に噴射される。したがって、各ダ
ンパ10の開度を調整すれば板幅方向の冷却速度を変えら
れる。このように、溶融めっき鋼板の板幅により各ダン
パ10の開度を調整して冷却媒体を有効に利用することが
できる。The cooling medium is sent from the blower 6 to the duct, passes through the inlet 7 installed at the lower part of the duct, passes through the damper 10, and is sent to the cooling medium flow path 4, and the cooling medium blows out from the cooling medium outlet 8. Injected to. Therefore, the cooling rate in the plate width direction can be changed by adjusting the degree of opening of each damper 10. As described above, the opening degree of each damper 10 is adjusted according to the width of the hot-dip coated steel sheet, so that the cooling medium can be effectively used.
【００３７】図５a および図５b には冷却装置を幅方向
を３分割した例を示したが、冷却装置の幅方向のセクシ
ョン分割をさらに多く (例：５分割、７分割) して、各
セクションにダンパを設けてもよい。例えば、図５b の
冷却セクションＡおよびＣをさらに各々２分割すれば、
鋼板の板幅に応じてさらに細かい冷却速度制御が可能と
なる。また、鋼板の板幅方向の温度分布が大きい場合に
は、その温度分布の状態に合わせて、図５b の冷却セク
ションＢを細かく分割 (例：３分割、５分割)して各冷
却セクションにそれぞれダンパ10を設けて風量調整を行
うことにより冷却速度を制御してもよく、このようにす
ることにより板幅方向の温度分布によるめっき皮膜特性
のバラツキを抑えて、板幅方向のスパングル粒径が均一
な溶融めっき皮膜を得ることができる。FIGS. 5A and 5B show an example in which the cooling device is divided into three in the width direction. However, the cooling device is further divided into sections in the width direction (eg, divided into five, divided into seven), and each section is divided. May be provided with a damper. For example, if the cooling sections A and C in FIG.
Finer cooling rate control is possible according to the width of the steel sheet. When the temperature distribution in the width direction of the steel sheet is large, the cooling section B in FIG. 5B is finely divided (for example, divided into three and five) according to the state of the temperature distribution, and each cooling section is divided into the respective cooling sections. The cooling rate may be controlled by providing a damper 10 and adjusting the air flow rate.By doing so, the variation in the plating film characteristics due to the temperature distribution in the sheet width direction is suppressed, and the spangle diameter in the sheet width direction is reduced. A uniform hot-dip coating can be obtained.
【００３８】さらに、図６a および図６b は、冷却媒体
流路４内および導入口７内にそれぞれダンパ９ａ、９
ｂ、10を設けた冷却装置を示すが、このように冷却装置
の長手方向および幅方向の両方における冷却媒体吐出量
を調整することも可能である。このような構成の装置で
あれば、図４a および図５a に示した装置の優れた点を
合わせ持つためその効果は非常に大きい。FIGS. 6A and 6B show dampers 9a, 9a in the coolant flow path 4 and in the inlet 7, respectively.
Although a cooling device provided with b and 10 is shown, it is also possible to adjust the cooling medium discharge amount in both the longitudinal direction and the width direction of the cooling device. The device having such a configuration has a very large effect because it has the advantages of the devices shown in FIGS. 4A and 5A.
【００３９】以上、風量調整設備としてダンパを用いた
場合を例にとって本発明冷却方法および冷却装置を説明
したが、冷却媒体吐出量を制御可能であれば、ダンパ以
外の他の機能を用いてもよい。例えば、スリットギャッ
プの幅方向における可変制御等も本発明に適用可能であ
る。以下に、異なる板厚の鋼板を連続して溶融めっきす
る場合、本発明にかかる冷却方法を用いた場合の溶融め
っき皮膜特性を示す。Although the cooling method and the cooling device of the present invention have been described by taking a damper as an air volume adjusting device as an example, other functions other than the damper may be used as long as the cooling medium discharge amount can be controlled. Good. For example, variable control in the width direction of the slit gap can be applied to the present invention. Hereinafter, the characteristics of the hot-dip coating film when the cooling method according to the present invention is used in the case where the hot-dip steel sheets having different thicknesses are successively hot-dipped are shown.
【００４０】溶融めっき鋼板の冷却において、ダンパ等
により冷却媒体吐出量を変化させると、各領域の冷却媒
体吐出量が相対的に変化して吐出量とめっき皮膜特性と
の関係が不明確になるため、ここでは図７に示すように
冷却装置長手方向の中央で上下２分割し、各々に別個の
送風装置から独立に冷却媒体を送り込んだ。空気を冷却
媒体とし、各々のダクト内に設けられた各ダンパにより
上下段の冷却ゾーンの各々の風量を独立に制御し、溶融
めっき鋼板に噴射した。上下段のダンパの開度を変えた
場合の溶融めっき鋼板のめっき皮膜特性を表１に示す。In the cooling of the hot-dip coated steel sheet, if the discharge amount of the cooling medium is changed by a damper or the like, the discharge amount of the cooling medium in each region relatively changes, and the relationship between the discharge amount and the plating film characteristics becomes unclear. For this reason, as shown in FIG. 7, here, the cooling device is divided into upper and lower portions at the center in the longitudinal direction, and the cooling medium is independently supplied from each of the separate blowers. Using air as a cooling medium, the air flow in each of the upper and lower cooling zones was independently controlled by each damper provided in each duct, and the air was injected onto the hot-dip coated steel sheet. Table 1 shows the plating film characteristics of the hot-dip coated steel sheet when the opening degree of the upper and lower dampers is changed.
【００４１】下段風量 (即ち、初期冷却速度) のみが増
すと、スパングルの平均粒径は小さくなり加工性は良好
になる。異なる厚みの鋼板を用いる場合には、ダンパ開
度を適宜調整すれば同程度のスパングル粒径とすること
ができる。なお、ダンパ開度が小さくなればその領域の
スリットノズルに送られる風量は増す。例えば、スパン
グル粒径が2.0 mmの溶融めっき鋼板を得る場合には、0.
4 mm厚鋼板の場合：下段０％−上段100 ％、0.8 mm厚鋼
板の場合：下段20％−上段100 ％、1.6 mm厚鋼板の場
合：下段80％−上段100 ％として冷却すればよい。When only the lower air volume (ie, the initial cooling rate) increases, the average particle size of spangles becomes smaller, and workability becomes better. When steel plates having different thicknesses are used, the spangle diameter can be made approximately the same by appropriately adjusting the damper opening. It should be noted that as the damper opening decreases, the amount of air sent to the slit nozzle in that area increases. For example, when obtaining a hot-dip coated steel sheet having a spangle particle size of 2.0 mm, a diameter of 0.
In the case of a 4 mm thick steel plate: lower 0% -upper 100%, in the case of 0.8 mm thick steel plate: lower 20% -upper 100%, 1.6 mm thick steel plate: lower 80% -upper 100%.
【００４２】本発明の冷却装置を用いた場合にも板厚に
応じて冷却パターンを変えれば、板厚に関わらずスパン
グル粒径を均一 (板厚間差が少ない) にすることができ
る。Even when the cooling device of the present invention is used, the spangle particle size can be made uniform (the difference between the plate thicknesses is small) irrespective of the plate thickness by changing the cooling pattern according to the plate thickness.
【００４３】[0043]
【表１】 [Table 1]
【００４４】実施例２ 表２に冷却装置を上下２分割し、それぞれの風量を独立
で制御したときの平均スパングル径の結果を示す。下段
のみの風量を落とすことによって、スパングル粒径を変
化させることが可能となる。Example 2 Table 2 shows the results of the average spangle diameter when the cooling device was divided into upper and lower parts and the airflow was controlled independently of each other. It is possible to change the spangle particle size by reducing the air volume only in the lower stage.
【００４５】[0045]
【表２】 [Table 2]
【００４６】実施例３ 表３に冷却装置を幅方向に３分割 (図５ａ、ｂ) し、セ
クションＡ、ＣはセットでセクションＢと独立に制御し
たときの平均スパングル径の結果を示す。セクションＢ
は通板板幅 (1000mm) の両エッジ 200mm (セクションＡ
およびＢ) を除く部分の風量制御ゾーンである。Example 3 Table 3 shows the results of the average spangle diameter when the cooling device was divided into three parts in the width direction (FIGS. 5A and 5B) and sections A and C were controlled independently of section B as a set. Section B
Is 200mm on both edges of section width (1000mm) (Section A
And the air flow control zones other than B).
【００４７】セクションＡとＣの冷媒流量をＢに比べ小
さくすることにより、スパングル粒径を幅方向で均一に
制御することが可能となる。そのとき、長手方向のダン
パー開度は、すべて100 ％とした。By making the refrigerant flow rates of the sections A and C smaller than that of the section B, the spangle particle size can be controlled uniformly in the width direction. At that time, the damper openings in the longitudinal direction were all 100%.
【００４８】[0048]
【表３】 [Table 3]
【００４９】[0049]
【発明の効果】以上説明してきたように、本発明によ
り、溶融めっきの目付量の調整直後に、溶融めっき鋼板
の急冷を行うことにより、装置全体が非常に簡便とな
り、しかもかかる冷却装置の長手方向および／または幅
方向における冷却媒体吐出量の制御するため、冷却媒体
の冷却能力を最大限に活用することができ、効率的に、
均一且つ良質なめっき皮膜特性 (スパングル粒径) を有
する溶融めっき鋼板の製造が可能となった。As described above, according to the present invention, by immediately cooling the hot-dip coated steel sheet immediately after adjusting the basis weight of the hot-dip coating, the entire apparatus becomes very simple, and the length of the cooling apparatus is reduced. In order to control the cooling medium discharge amount in the direction and / or the width direction, the cooling capacity of the cooling medium can be maximized, and
It has become possible to manufacture hot-dip coated steel sheets having uniform and good quality plating film characteristics (spangle diameter).
【図１】55wt％Al−Zn合金めっき直後の鋼板の冷却速度
−スパングル平均粒径の関係を示すグラフである。FIG. 1 is a graph showing the relationship between the cooling rate of a steel sheet immediately after 55 wt% Al-Zn alloy plating and the average spangle diameter.
【図２】本発明にかかる溶融金属めっき鋼板の製造装置
の模式図である。FIG. 2 is a schematic diagram of an apparatus for manufacturing a hot-dip metal-plated steel sheet according to the present invention.
【図３】図２の溶融金属めっき鋼板の冷却装置のスリッ
トノズル部の模式図である。FIG. 3 is a schematic view of a slit nozzle portion of the cooling device for a hot-dip metal-plated steel sheet of FIG. 2;
【図４】図４ａは冷却媒体流路内にダンパを設けた本発
明冷却装置の概略説明図であり、図４ｂは図４ａのＹ−
Ｙ' 線方向からみた冷却媒体流路４の正面図である。4A is a schematic explanatory view of a cooling device of the present invention in which a damper is provided in a cooling medium flow path, and FIG.
FIG. 4 is a front view of the cooling medium flow path 4 as viewed from the direction of the line Y ′.
【図５】図５ａはダクト内にダンパを設けた本発明冷却
装置の概略説明図であり、図５ｂは図５ａのＹ−Ｙ’線
方向からみた冷却媒体流路４の正面図である。5A is a schematic explanatory view of the cooling device of the present invention in which a damper is provided in a duct, and FIG. 5B is a front view of the cooling medium flow path 4 as viewed from the direction of line YY ′ in FIG. 5A.
【図６】図６ａは、冷却媒体流路内およびダクト内にダ
ンパを設けた本発明冷却装置であり、図６ｂは図６ａの
Ｙ−Ｙ’線方向からみた冷却媒体流路４の正面図であ
る。6A is a cooling device of the present invention in which dampers are provided in a cooling medium flow path and a duct, and FIG. 6B is a front view of the cooling medium flow path 4 as viewed from the direction of line YY ′ in FIG. 6A. It is.
【図７】上下２分割した本発明の例の実施例で用いた冷
却装置の概略説明図である。FIG. 7 is a schematic explanatory view of a cooling device used in an embodiment of the present invention divided into upper and lower parts.
１・・・溶融金属めっき浴 ２・・・シンク
ロール ３・・・ワイピングノズル ４・・・冷却媒
体流路 ５・・・鋼板 ６・・・送風装
置 ７・・・導入口 ８・・・冷却ガ
ス吹き出し口 9a, 9b, 10, 11a, 11b・・・ダンパ 12・・・セクシ
ョン区分板DESCRIPTION OF SYMBOLS 1 ... Molten metal plating bath 2 ... Sink roll 3 ... Wiping nozzle 4 ... Cooling medium flow path 5 ... Steel plate 6 ... Blower 7 ... Inlet 8 ... Cooling Gas outlet 9a, 9b, 10, 11a, 11b ・ ・ ・ Damper 12 ・ ・ ・ Section section plate
───────────────────────────────────────────────────── フロントページの続き (72)発明者 松永 貴裕 和歌山市湊1850番地 住友金属工業株式 会社和歌山製鉄所内 (56)参考文献 特開 昭56−84456（ＪＰ，Ａ) 実開 平５−35848（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.6，ＤＢ名) C23C 2/00 - 2/40 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takahiro Matsunaga 1850 Minato, Wakayama-shi Sumitomo Metal Industries Co., Ltd. Wakayama Works (56) References JP-A-56-84456 (JP, A) JP, U) (58) Field surveyed (Int. Cl. 6 , DB name) C23C 2/00-2/40
Claims (3)
っき鋼板の目付け量を調整してから直ちに冷却装置にお
いて溶融めっき鋼板を冷却し、該冷却装置の鋼板走行方
向に沿って冷却速度を制御するとともに、該冷却装置に
よる冷却開始時に溶融めっき鋼板を急冷することによっ
てスパングル特性を制御することを特徴とする溶融めっ
き鋼板の冷却方法。1. A method for cooling a hot-dip coated steel sheet in a cooling device immediately after adjusting a basis weight of the hot-dip coated steel sheet pulled up from the hot-dip coating bath, controlling a cooling rate of the hot-dip coated steel sheet in a running direction of the steel plate. A method for cooling a hot-dip coated steel sheet by rapidly cooling the hot-dip coated steel sheet at the start of cooling by the cooling device to control spangle characteristics.
き続いて設ける冷却装置であって、鋼板の幅方向に延び
た平行スリットノズルを長手方向に多段に設け、それら
のスリットノズル列の全体を複数の冷却ゾーンに区画
し、これらの各冷却ゾーンが独立して冷却媒の流速を制
御できるように構成するとともに前記冷却ゾーンを幅方
向においてもスリットノズルの背後に仕切り板を設ける
ことで複数の冷却セクションに区画し、これらの冷却セ
クションが独立して冷却媒の流速を制御できるように構
成したことを特徴とする溶融めっき鋼板のスパングル特
性を制御する冷却装置。2. A cooling device provided subsequent to a basis weight adjusting means for a hot-dip coated steel sheet, wherein a plurality of parallel slit nozzles extending in a width direction of the steel sheet are provided in multiple stages in a longitudinal direction, and the entirety of the slit nozzle rows is provided in plural. The cooling zones are divided into cooling zones, and each of these cooling zones is configured to be able to independently control the flow rate of the cooling medium, and a plurality of cooling zones are provided in the width direction by providing a partition plate behind the slit nozzle in the width direction. A cooling device for controlling spangle characteristics of a hot-dip coated steel sheet, wherein the cooling section is divided into sections, and the cooling sections are configured to be able to independently control the flow rate of a cooling medium.
移動自在に設置した請求項２に記載の溶融めっき鋼板の
スパングル特性を制御する冷却装置。3. The cooling apparatus for controlling spangle characteristics of a hot-dip coated steel sheet according to claim 2, wherein the entire cooling apparatus is installed so as to be movable in the traveling direction of the coated steel sheet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6785795A JP2964905B2 (en) | 1995-03-27 | 1995-03-27 | Method and apparatus for cooling hot-dip coated steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6785795A JP2964905B2 (en) | 1995-03-27 | 1995-03-27 | Method and apparatus for cooling hot-dip coated steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08269664A JPH08269664A (en) | 1996-10-15 |
| JP2964905B2 true JP2964905B2 (en) | 1999-10-18 |
Family
ID=13357042
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6785795A Expired - Fee Related JP2964905B2 (en) | 1995-03-27 | 1995-03-27 | Method and apparatus for cooling hot-dip coated steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2964905B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4820070B2 (en) * | 2004-09-02 | 2011-11-24 | 日鉄住金鋼板株式会社 | Method for producing molten aluminum-zinc alloy plated steel sheet |
| JP5060245B2 (en) * | 2007-10-31 | 2012-10-31 | 新日鉄エンジニアリング株式会社 | Steel strip cooling device |
| KR101568567B1 (en) * | 2014-01-27 | 2015-11-11 | 주식회사 포스코 | Apparatus for cooling coated strip |
-
1995
- 1995-03-27 JP JP6785795A patent/JP2964905B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08269664A (en) | 1996-10-15 |
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