JPH1053885A - Method for controlling pickling of cold-rolled steel strip different to rolling reduction and pickling device - Google Patents
Method for controlling pickling of cold-rolled steel strip different to rolling reduction and pickling deviceInfo
- Publication number
- JPH1053885A JPH1053885A JP22442096A JP22442096A JPH1053885A JP H1053885 A JPH1053885 A JP H1053885A JP 22442096 A JP22442096 A JP 22442096A JP 22442096 A JP22442096 A JP 22442096A JP H1053885 A JPH1053885 A JP H1053885A
- Authority
- JP
- Japan
- Prior art keywords
- pickling
- steel strip
- rolling
- cold
- scale
- 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.)
- Withdrawn
Links
- 238000005554 pickling Methods 0.000 title claims abstract description 111
- 238000005096 rolling process Methods 0.000 title claims abstract description 45
- 230000009467 reduction Effects 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title claims description 13
- 239000010960 cold rolled steel Substances 0.000 title description 10
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 72
- 239000010959 steel Substances 0.000 claims abstract description 71
- 238000005097 cold rolling Methods 0.000 claims abstract description 27
- 239000007788 liquid Substances 0.000 claims abstract description 18
- 238000007654 immersion Methods 0.000 claims description 11
- 241000316887 Saissetia oleae Species 0.000 claims description 10
- 238000005192 partition Methods 0.000 claims description 5
- 239000002253 acid Substances 0.000 abstract description 24
- 238000007598 dipping method Methods 0.000 abstract description 4
- 239000000463 material Substances 0.000 abstract description 3
- 239000000243 solution Substances 0.000 description 8
- 230000008859 change Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 230000008569 process Effects 0.000 description 6
- 239000003517 fume Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 238000005452 bending Methods 0.000 description 2
- 230000001680 brushing effect Effects 0.000 description 2
- 238000011143 downstream manufacturing Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000002436 steel type Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
Landscapes
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、熱間圧延鋼帯を軽圧下
から高圧下圧延までの圧下率の異なる圧延条件で冷間圧
延した冷延鋼帯の酸洗方法及び酸洗用装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for pickling a cold-rolled steel strip obtained by cold rolling a hot-rolled steel strip under different rolling reductions from light reduction to high-pressure rolling. .
【０００２】[0002]
【従来の技術】熱間圧延された鋼帯は、酸化物を主体と
するスケールで表面が覆われている。この熱延鋼帯を、
そのまま冷延等の下流工程に送ると、熱延スケールに起
因する表面疵やクラック等の欠陥が発生する原因とな
る。そこで、通常、酸洗によって熱延スケールを除去
し、熱延鋼帯を下流工程に搬送している。この方法で
は、酸洗設備，廃酸処理，脱スケール能の調整等の点で
問題があり、また酸洗時に発生する水素の侵入によって
鋼材の特性が劣化する虞れもある。酸洗に起因する諸問
題を解決するため、酸洗工程に送り込まれる熱延鋼帯の
スケールを除去する方法が種々検討されている。たとえ
ば、スケールが付着した熱延鋼帯を高圧下率で冷間圧延
すること（以下、黒皮圧延という）が特公昭５４−１３
３４６０号公報，特開昭５７−４１８２１号公報、特開
昭５７−１０９１７号公報等で紹介されている。高圧下
率の冷間圧延により、スケールに亀裂が発生し、また鋼
帯に対する付着力が低下するので、ショットブラスト，
高圧水噴射，ブラッシング，砥粒研削等により冷間圧延
後の鋼帯からスケールが容易に分離される。その結果、
酸洗槽に搬入される熱延鋼帯に付着しているスケールが
少なくなり、酸洗工程の負荷が軽減する。2. Description of the Related Art A hot-rolled steel strip is covered with a scale mainly composed of an oxide. This hot rolled steel strip
If it is sent to a downstream process such as cold rolling as it is, it causes defects such as surface flaws and cracks due to the hot rolling scale. Therefore, the hot rolled scale is usually removed by pickling, and the hot rolled steel strip is transported to a downstream process. This method has problems in pickling equipment, waste acid treatment, adjustment of descaling ability, and the like, and there is also a possibility that the properties of the steel material may be deteriorated due to intrusion of hydrogen generated during pickling. In order to solve various problems caused by the pickling, various methods for removing the scale of the hot-rolled steel strip sent to the pickling step have been studied. For example, cold rolling of a hot-rolled steel strip to which scale has been attached at a high pressure ratio (hereinafter referred to as black scale rolling) is described in Japanese Patent Publication No. 54-13 / 1979.
No. 3,460, JP-A-57-41821, JP-A-57-10917, and the like. Cold rolling at a high pressure ratio causes cracks in the scale and lowers the adhesive force to the steel strip.
The scale is easily separated from the steel strip after cold rolling by high-pressure water injection, brushing, abrasive grinding, or the like. as a result,
The scale attached to the hot-rolled steel strip carried into the pickling tank is reduced, and the load of the pickling process is reduced.
【０００３】[0003]
【発明が解決しようとする課題】熱延鋼帯を高圧下率で
黒皮圧延するとき、確かに酸洗工程の負荷が軽減される
ものの、上記したように、高圧下率圧延により鋼帯に強
固に付着したスケールに亀裂が入るなどの作用の結果、
メカニカルデスケーリング工程におけるスケールの剥離
はもとより、酸洗における溶解が起こりやすくなるもの
であるから、酸浴に対する浸漬時間や浴濃度及び浴温な
どの変化に対する影響も強く現れる傾向にある。このよ
うな高圧下率が熱延鋼帯のディスケーリングに有効であ
る理由を、本発明者等は次のように考察した。熱延鋼帯
の表面に形成されているスケールは、酸素濃度が順次高
くなるＦｅＯ層，Ｆｅ3 Ｏ4 層及びＦｅ2 Ｏ3 層が基地
鋼の表面に積層された構造を持っており、Ｆｅ3 Ｏ4 層
及びＦｅ2 Ｏ3 層は硬質で脆く、比較的低い圧下力でも
クラックが入り易い。たとえば、酸洗の前工程として組
み込まれている従来のテンションレベラー程度の圧下力
（約２％）及び機械的な繰返し曲げ加工でも、クラック
が入り、スケール層界面で剥離する。When a hot-rolled steel strip is subjected to black scale rolling at a high reduction rate, although the load of the pickling step is certainly reduced, as described above, the steel strip is formed by the high-pressure reduction rolling. As a result of the action such as cracking of the firmly attached scale,
Dissolution in pickling, as well as peeling of scale in the mechanical descaling step, is likely to occur, and therefore, there is a tendency that the influence on changes in immersion time in an acid bath, bath concentration, bath temperature, and the like is strongly exhibited. The present inventors have considered the reason why such a high-pressure reduction is effective for the descaling of the hot-rolled steel strip as follows. The scale formed on the surface of the hot-rolled steel strip has a structure in which an FeO layer, an Fe 3 O 4 layer, and an Fe 2 O 3 layer in which the oxygen concentration increases sequentially are laminated on the surface of the base steel. The 3 O 4 layer and the Fe 2 O 3 layer are hard and brittle, and easily crack even with a relatively low rolling force. For example, cracks occur even in a mechanically repeated bending process and a rolling force (about 2%) of a conventional tension leveler incorporated as a pre-process of pickling, and peeling occurs at the scale layer interface.
【０００４】これに対し、基地鋼との界面にあるＦｅＯ
層は、展延性があり、低い圧下率では基地鋼の伸びに従
って変形する。そのため、テンションレベラー程度の圧
下力では下地鋼から剥離せず、酸洗槽に持ち込まれる。
しかし、圧下率を１０％以上に高く設定すると、基地鋼
とＦｅＯ層との変形量の差が大きくなり、基地鋼の伸び
に追従できなくなったＦｅＯ層は、基地鋼との間に層間
剥離を発生させる。実際、冷間圧延で熱延鋼帯表面から
剥離したスケールの粉砕物を調査してみると、圧下率が
低いときには剥離したスケールが粉粒状であるのに対
し、圧下率の上昇に伴って粉砕物のサイズが大きく鱗片
状になってくることが観察される。この圧下率に応じた
剥離スケールの状態変化は、低圧下率の圧延ではＦｅ3
Ｏ4 層からスケールが剥離し、高圧下率の圧延ではＦｅ
Ｏ層からスケールが剥離することを意味する。On the other hand, FeO at the interface with the base steel
The layers are malleable and deform at low rolling reductions according to the elongation of the base steel. Therefore, the steel sheet is not peeled off from the base steel with a rolling force of about the tension leveler and is taken into the pickling tank.
However, when the rolling reduction is set to 10% or more, the difference in the amount of deformation between the base steel and the FeO layer increases, and the FeO layer which cannot follow the elongation of the base steel delaminates from the base steel. generate. In fact, when examining the pulverized material of the scale peeled from the surface of the hot-rolled steel strip by cold rolling, when the rolling reduction is low, the peeled scale is powdery and granular, but it is pulverized with the increase of the rolling reduction. It is observed that the size of the object becomes large and scale-like. The state change of the peel scale in accordance with the rolling reduction is that Fe 3
The scale is peeled off from the O 4 layer.
It means that the scale is separated from the O layer.
【０００５】ＦｅＯ層と下地鋼との界面からスケールが
剥離されると、圧延後の鋼帯表面に残存するスケールが
大幅に少なくなる。そこで、冷間圧延後の鋼帯表面をブ
ラッシングし、次いで高圧水スプレーすることにより鋼
帯表面から残存スケールを除去することができるのであ
り、このようなメカニカルデスケーリングの効果を加味
すると、予想以上にスケールの除去が行われ、酸洗槽に
おける酸洗条件が大幅に緩和される。すなわち、このよ
うな高圧下率による冷間圧延によればメカニカルデスケ
ーリングの効果も含め、酸洗工程の負荷を大幅に下げ
て、速やかな酸洗の進行ができるが、一方その圧下率の
程度によってこれらのメカニカルデスケーリングの効果
を含め冷延鋼帯のスケール除去の容易さや酸洗工程まで
のスケール除去の程度が変化するため、酸洗工程におけ
る負荷も大きく変わることとなる。[0005] When the scale is peeled off from the interface between the FeO layer and the base steel, the scale remaining on the surface of the steel strip after rolling is significantly reduced. Therefore, it is possible to remove the remaining scale from the surface of the steel strip by brushing the surface of the steel strip after cold rolling and then spraying with high-pressure water. The scale is removed, and the pickling conditions in the pickling tank are greatly reduced. That is, according to the cold rolling with such a high reduction rate, the load of the pickling step can be significantly reduced, including the effect of mechanical descaling, and the pickling can proceed promptly. Accordingly, the ease of scale removal of the cold-rolled steel strip including the effect of mechanical descaling and the degree of scale removal up to the pickling step change, so that the load in the pickling step also changes greatly.
【０００６】実用上、熱延鋼帯の冷間圧延の程度も、ス
キンパス程度の軽圧下率から５０％以上の高圧下率まで
の広い範囲に行われており、その下流工程に当たる酸洗
工程はこれらの幅広い条件に対処しなければならない。
これに対処するため、酸洗槽に対する鋼帯の浸漬時間を
制御することが必要であるが、従来、ラインスピードを
制御して浸漬時間を変えることが行われていた。しかし
ながら、従来のこのようなラインスピードによる制御
は、酸洗工程の負荷にあまり差がない場合に行われてい
た方法であって、前記黒皮圧延のような熱延鋼板の高圧
下率冷延鋼板の場合は、圧下率の差によってスケール除
去の容易さや程度に著しい差が現れるため、ラインスピ
ードのみで対処することには自ずと限界があった。ライ
ンスピードは圧下率の変化によって変化するが、一方で
圧延条件などから求められる適切なスピードがあり、大
幅な変更はし難い。また、圧延条件上ラインスピードの
低下は生産効率からも好ましくない。[0006] In practice, the degree of cold rolling of a hot-rolled steel strip is also performed in a wide range from a light rolling reduction of about skin pass to a high rolling reduction of 50% or more. These broad conditions must be addressed.
To cope with this, it is necessary to control the immersion time of the steel strip in the pickling tank. Conventionally, the immersion time was changed by controlling the line speed. However, such conventional control by the line speed is a method performed when there is not much difference in the load of the pickling process, and the high-pressure cold rolling of a hot-rolled steel sheet such as the black scale rolling is performed. In the case of steel sheets, there is a marked difference in the ease and extent of scale removal due to the difference in draft, and there was naturally a limit in dealing with only line speed. The line speed changes depending on the reduction ratio, but on the other hand, there is an appropriate speed required from rolling conditions and the like, and it is difficult to make a significant change. In addition, a reduction in line speed is not preferable in terms of production efficiency due to rolling conditions.
【０００７】しかも、高圧下率冷延鋼板の酸洗条件は、
上記したようなスケール除去の効果から短時間で酸洗が
終了するものの、一方このため浸漬時間などの酸洗条件
の変化に対して極めて敏感であり、適正な浸漬時間を越
えると、速やかに過酸洗に陥る。又これに対し、圧下率
の低い冷延鋼板の場合は、メカニカルデスケーリングの
効果も低く、酸洗工程において十分な浸漬時間を取る必
要があるが、上記したように、圧延工程の生産性などか
らラインスピードの低下には自ら制約がある。酸洗工程
は、これら冷延工程にいたる一連の連続工程の下流工程
であり、これらの酸洗条件の異なる冷延鋼帯のいずれの
酸洗条件にも対応する必要があるが、これらの酸洗条件
や特性には上記したように著しい差があり、従来のライ
ンスピードの制御のみによる方法のみでは対処すること
はできない。このような酸洗条件を制御する方法とし
て、ラインスピードを変更するほか、酸液の濃度や温度
を調節する方法があるが、これらの条件の変更は酸洗し
た鋼帯の表面仕上がりに影響があり、好ましくない。
又、酸洗長を可変とすることで対処することが考えら
れ、酸洗ラインを複数の酸洗槽で構成し、その上方を走
行する鋼帯を浸漬ロールにより所定の槽に導入して浸漬
せしめることが特公平５−３０９１７号公報に提案され
ているが、浸漬ロールと搬送ロールとの間で鋼帯を屈曲
させ、張力を負荷するための機械的移動装置を、著しく
腐食性の高い酸ヒュームの発生源近傍に設ける必要があ
り、装置寿命の点で問題が多い。また、この移動機構は
鋼帯を上下移動するため、ヒュームのシール性を著しく
損ない、その相乗作用で周辺の装置の劣化は免れない。[0007] In addition, the pickling conditions of a high-pressure cold-rolled steel sheet are as follows:
Although the pickling is completed in a short time due to the effect of scale removal as described above, on the other hand, it is extremely sensitive to changes in pickling conditions such as immersion time. Fall into pickling. On the other hand, in the case of a cold-rolled steel sheet having a low draft, the effect of mechanical descaling is low, and it is necessary to take a sufficient immersion time in the pickling step. Therefore, the reduction in line speed has its own restrictions. The pickling step is a downstream step of a series of continuous steps up to the cold rolling step, and it is necessary to cope with any pickling conditions of the cold rolled steel strip having different pickling conditions. As described above, there are remarkable differences in washing conditions and characteristics, and it cannot be dealt with only by a conventional method using only line speed control. Methods for controlling such pickling conditions include changing the line speed and adjusting the concentration and temperature of the acid solution. Changing these conditions affects the surface finish of the pickled steel strip. Yes, not preferred.
It is also conceivable to cope with the problem by making the pickling length variable.The pickling line is composed of a plurality of pickling tanks, and a steel strip traveling above the pickling tank is introduced into a predetermined tank by a dipping roll and dipped. Japanese Patent Publication No. Hei 5-30917 proposes that a mechanical moving device for bending a steel strip between a immersion roll and a transport roll and applying tension thereto is provided with a significantly corrosive acid. It is necessary to provide it near the fume generation source, and there are many problems in terms of device life. In addition, since this moving mechanism moves up and down the steel strip, the sealing performance of the fume is significantly impaired, and the synergistic action inevitably deteriorates peripheral devices.
【０００８】本発明は、このような熱延鋼帯の軽圧下率
から高圧下率に至る冷延後の鋼帯の酸洗に対して同じ設
備によって対処可能であり、圧延条件の変更を必要とす
るようなラインスピードの変更を必要とせず、かつ、従
来の酸洗条件及び設備の大幅な変更を必要としない、酸
洗設備を提供することを目的とする。また、黒皮圧延鋼
帯に見るような酸洗条件に敏感な鋼帯の酸洗を高い制御
精度で行うことを目的とする。The present invention can cope with such pickling of a cold-rolled steel strip from a light reduction rate to a high-pressure reduction rate of a hot-rolled steel strip by the same equipment, and it is necessary to change rolling conditions. It is an object of the present invention to provide a pickling facility that does not require a change in line speed as described above and does not require a significant change in conventional pickling conditions and facilities. Another object of the present invention is to perform pickling of a steel strip that is sensitive to pickling conditions as seen in a black scale rolled steel strip with high control accuracy.
【０００９】[0009]
【課題を解決するための手段】本発明は、その目的を達
成するため、黒皮圧延を行う冷間圧延機の下流側で、冷
間圧延の圧下率及びラインスピードに応じて２以上の酸
洗槽の内適数の槽の液面を低下させて鋼帯を浴面上方を
通過させて浸漬時間を制御することを特徴とする。ま
た、そのため、スケールが付着している熱延鋼帯を高圧
下圧延する冷間圧延機の下流側で、２以上の複数の酸洗
槽又は２以上の区画に仕切ってなる酸洗槽を設け、各槽
または仕切りごとにロールを設けて通板するように構成
し、各槽の液面をそれぞれ独立に上下可能として通板時
に鋼板が浸漬する槽の数を、冷間圧延の圧下率及びライ
ンスピードに応じて制御するようにしてなることを特徴
とする。According to the present invention, in order to achieve the object, two or more acids are provided downstream of a cold rolling mill for performing black scale rolling according to the rolling reduction and the line speed of the cold rolling. It is characterized in that the liquid level in an appropriate number of the washing tanks is lowered, and the steel strip is passed above the bath surface to control the immersion time. Also, for this purpose, a pickling tank provided with two or more pickling tanks or two or more sections is provided on the downstream side of a cold rolling mill that performs high-pressure rolling of a hot-rolled steel strip to which scale is attached. , A roll is provided for each tank or partition to pass through, and the liquid level of each tank can be independently raised and lowered, and the number of tanks in which the steel sheet is immersed at the time of passing, the rolling reduction of cold rolling and It is characterized in that control is performed according to the line speed.
【００１０】[0010]
【本発明の実施の形態】本発明に従ったラインは、図１
に示すように構築される。熱延スケールが付着したまま
の熱延鋼帯は、ペイオフリールから巻き戻され、ブライ
ドルロールを経て冷間圧延機で圧延される。高圧下圧延
する場合、熱延スケールは、高圧下圧延によって亀裂，
粉砕され、鋼帯から剥離される。鋼帯表面に残留してい
るスケール粉砕物をブラシロールで除去した後、更にス
プレー装置に導入され、スプレーノズルから高圧水を吹
き付けることによって鋼帯の表面が清浄化される。この
ように処理された鋼帯は、次いで酸洗槽に送り込まれ、
表面に僅かに残っているスケールが酸洗除去される。DETAILED DESCRIPTION OF THE INVENTION The line according to the invention is shown in FIG.
It is constructed as shown in The hot-rolled steel strip with the hot-rolled scale adhered is unwound from a pay-off reel and rolled by a cold rolling mill via bridle rolls. When rolling under high pressure, the hot rolled scale cracks,
Crushed and peeled from steel strip. After the scale pulverized matter remaining on the steel strip surface is removed by a brush roll, it is further introduced into a spray device, and the surface of the steel strip is cleaned by spraying high-pressure water from a spray nozzle. The steel strip thus treated is then sent to a pickling tank,
The scale remaining slightly on the surface is pickled and removed.
【００１１】これら冷間圧延鋼帯としては、スキンパス
としての３〜４％程度の圧下率から、冷間圧延の圧下率
２０〜３０％及び３０〜５０％の高圧下率のものでよ
い。これらの圧下率は、酸洗後の次工程に応じて決定さ
れるが、次に述べる酸洗槽浸漬時間の制御によってこれ
らの広い圧下率範囲に対処することができるため、これ
らの圧下率範囲に格別の制限はない。These cold-rolled steel strips may have a rolling reduction of about 3 to 4% as a skin pass, and a high rolling reduction of 20 to 30% and 30 to 50% for cold rolling. These rolling reductions are determined according to the next step after pickling. However, by controlling the immersion time of the pickling tank described below, it is possible to cope with these wide rolling reduction ranges. There are no special restrictions.
【００１２】酸洗槽は、図１にその一例を示すように、
仕切壁５、６、及び７によって仕切られた酸洗槽１、
２、及び３からなる。これら酸洗槽の前後壁及び各仕切
壁上には熱延鋼帯１０を通板する案内ロール１１が設け
られ、鋼帯を酸浴に浸漬する一定の高さに支持案内す
る。槽１１上にはフード１５が設けられて酸ヒュームの
飛散を防止する。各酸洗槽には、新酸を供給する配管と
バルブＶ−１、２、３が配置され、また、これらの各酸
洗槽から酸液を抽出・供給するバルブＶ−１、２、３、
タンクＴ−１、２、３及びポンプＰ−１、２、３からな
る液面調節装置が設けられている。酸洗条件を制御する
には、図において、酸洗槽を３槽共使用する場合、新酸
をバルブＶ−１より供給し、バルブＶ−２及び３を閉と
して酸洗槽１〜３に酸液を満たす。鋼帯１０は案内ロー
ル１１により一定の高さに支持案内されているため、３
槽すべてに浸漬されて酸洗される。２槽使用する場合
は、新酸をバルブＶ−２より供給し、酸洗槽１の酸液を
バルブＶ−４よりタンクＴ−１へ送って、液面を低下さ
せ、鋼帯１０を酸浴液面上を通過させる。１槽使用する
場合も同様に、バルブＶ−３より酸液を供給すると共
に、バルブＶ１及び２よりタンクＴ−１及び２に酸洗槽
１及び２の酸液を送って、液面を低下させる。これらの
酸洗槽を再度使用する際には、これらのタンクに貯蔵さ
れた酸液をポンプＰ−１及び３により酸洗槽に送って液
面を上昇させ、上方のバルブＶ−１及び２より新酸を供
給すればよい。使用後の酸液は、下流より排出されて廃
酸回収設備に送られる。As shown in FIG. 1, an example of the pickling tank is as follows.
Pickling tank 1, which is partitioned by partition walls 5, 6, and 7,
It consists of 2 and 3. Guide rolls 11 for passing the hot-rolled steel strip 10 are provided on the front and rear walls and the partition walls of these pickling tanks, and support and guide the steel strip at a certain height to be immersed in the acid bath. A hood 15 is provided on the tank 11 to prevent the acid fume from scattering. In each pickling tank, a pipe for supplying new acid and valves V-1, 2, and 3 are arranged, and valves V-1, 2, and 3 for extracting and supplying an acid solution from each pickling tank. ,
A liquid level control device including tanks T-1, 2, 3 and pumps P-1, 2, 3 is provided. To control the pickling conditions, in the figure, when three pickling tanks are used, fresh acid is supplied from the valve V-1 and the valves V-2 and V3 are closed and the pickling tanks 1 to 3 are supplied. Fill with acid solution. Since the steel strip 10 is supported and guided at a constant height by the guide roll 11,
It is immersed in all the tanks and pickled. When two tanks are used, fresh acid is supplied from the valve V-2, and the acid solution in the pickling tank 1 is sent from the valve V-4 to the tank T-1 to lower the liquid level and the steel strip 10 is acidified. Pass over the bath surface. Similarly, when using one tank, the acid solution is supplied from the valve V-3 and the acid solution in the pickling tanks 1 and 2 is sent from the valves V1 and 2 to the tanks T-1 and T2 to lower the liquid level. Let it. When these pickling tanks are to be used again, the acid solution stored in these tanks is sent to the pickling tank by pumps P-1 and P3 to raise the liquid level, and the upper valves V-1 and V-2. What is necessary is just to supply new acid. The used acid solution is discharged from the downstream and sent to a waste acid recovery facility.
【００１３】スキンパスのように軽圧下程度の場合は酸
洗工程の負荷は大きいため、すべての酸洗槽を通板する
必要があり、ラインスピードも小さくして浸漬時間を長
くする必要がある。これに対し、熱延鋼帯を冷間圧延し
た冷延鋼帯は、冷間圧延時の圧下率の大小により酸洗工
程の負荷が異なるため、圧下率に応じて通板する酸洗槽
の数を制御する。典型的な黒皮圧延のような圧下率の大
きい場合は、メカニカルデイスケーリングの効果も大き
く、酸洗工程の負荷は極めて小さくしかも過酸洗になり
やすいことから、通板する酸洗槽の数を最小とし、ある
いは酸洗槽の長さをこれらの圧下率に合わせた酸洗能力
に応じた長さとしておき、適宜の酸洗槽を選択して他の
酸洗槽の液面を低下させてその上方を通板することによ
り、過酸洗とならない適宜な酸洗条件を選択することが
できる。以下に、具体的な実施例により説明する。表１
に使用した鋼種を、表２にその圧下率と酸洗条件との関
係を示す。なお、表２の条件においては、両鋼種共に同
じ条件下で、同様の酸洗効果が得られたため、表１の鋼
種に共通である。In the case of under a slight pressure, such as a skin pass, since the load of the pickling step is large, it is necessary to pass all the pickling tanks, and it is necessary to reduce the line speed and lengthen the immersion time. On the other hand, the cold-rolled steel strip obtained by cold-rolling the hot-rolled steel strip has a different load in the pickling process depending on the reduction ratio during cold rolling. Control the number. When the rolling reduction is large, as in typical black scale rolling, the effect of mechanical descaling is large, and the load of the pickling process is extremely small. Or minimize the length of the pickling tank according to the pickling capacity according to these rolling reduction rates, and select an appropriate pickling tank to lower the liquid level of the other pickling tanks. By passing the plate above, appropriate pickling conditions that do not result in over-acid pickling can be selected. Hereinafter, a specific example will be described. Table 1
Table 2 shows the relationship between the rolling reduction and pickling conditions. Under the conditions shown in Table 2, the same pickling effect was obtained under the same conditions for both steel types, and therefore, they are common to the steel types shown in Table 1.
【００１４】 [0014]
【００１５】 [0015]
【００１６】すなわち実用上ラインスピードの制御可能
な範囲１００〜２８０ｍ／分に対して、圧下率３〜４％
の程度の軽圧下率（スキンパス）では、ラインスピード
２００ｍ／分で酸洗槽数３（最大）として実用に耐える
表面状態が得られたが、ラインスピードを２８０ｍ／
分、酸洗槽数３（最大）において良好な酸洗結果を得
た。これに対し酸洗槽数を２に減ずると酸洗効果は不十
分であった。また、圧下率を最大の５０％（黒皮圧延）
とした場合では、ラインスピード２８０ｍ／分、及び２
００ｍ／分で、酸洗槽数１（最小）として適切な酸洗条
件とすることができたが、ラインスピード２８０ｍ／分
において、酸洗槽数３（最大）の条件下では、過酸洗と
なって不可であった。以上の結果に見るとおり、これら
の冷延鋼帯を通板する酸洗槽の数を圧下率に応じて制御
することにより、実用的なラインスピードの範囲で適切
な酸洗条件の制御が可能である。That is, the reduction rate is 3 to 4% for the practically controllable range of the line speed of 100 to 280 m / min.
With a light reduction rate (skin pass) of the order of 2, a practically acceptable surface state was obtained with a line speed of 200 m / min and a pickling tank number of 3 (maximum), but the line speed was increased to 280 m / min.
A good pickling result was obtained in a pickling tank number of 3 (maximum). On the other hand, if the number of pickling tanks was reduced to 2, the pickling effect was insufficient. In addition, the maximum reduction is 50% (black scale rolling)
, The line speed is 280 m / min and 2
At a speed of 00 m / min, the pickling tank number was 1 (minimum), which was suitable for pickling conditions. However, at a line speed of 280 m / min, a pickling tank number of 3 (maximum) was used. It was impossible. As can be seen from the above results, by controlling the number of pickling tanks that pass through these cold-rolled steel strips according to the rolling reduction, it is possible to control appropriate pickling conditions within a practical line speed range. It is.
【００１７】これら２以上の酸洗槽又は２以上の酸洗槽
の区画のそれぞれの長さは、同じである必要はなく、酸
洗処理の制御に適した組み合わせを考慮して定めれば良
い。操業上、酸洗工程の負荷の最も大きい軽圧下率の場
合に合わせて酸洗槽の容量を設定する必要があるが、本
発明はその槽を２以上に区分して、それぞれの区分され
た槽ごとに浴液面を制御して、必要な浸漬長さのみ鋼帯
が浸漬するようにすることにより、軽圧下率の鋼帯の酸
洗時に必要以上のラインスピードの低下を来すことがな
い。また、高圧下率の黒皮圧延鋼帯の酸洗の場合にも、
ラインスピードなどの調整と組み合わせることによっ
て、微妙な酸洗条件の制御が可能であり、過酸洗に陥る
ことなく適切な酸洗をすることができる。The lengths of the two or more pickling tanks or the sections of the two or more pickling tanks need not be the same, and may be determined in consideration of a combination suitable for controlling the pickling treatment. . In operation, it is necessary to set the capacity of the pickling tank in accordance with the case of the light draft of the largest load in the pickling step, but in the present invention, the tank is divided into two or more, and each of the divided tanks is divided. By controlling the bath liquid level in each bath so that the steel strip is immersed only for the required immersion length, the line speed can be reduced more than necessary when pickling steel strips with a light reduction rate. Absent. Also, in the case of pickling black scale rolled steel strip at high pressure,
By combining it with adjustment such as line speed, delicate pickling conditions can be controlled, and appropriate pickling can be performed without falling into over-picking.
【００１８】[0018]
【発明の効果】以上に説明したように、本発明によれ
ば、同一の酸洗設備によって熱延鋼帯の冷間圧延の圧下
率の大小の変化に応じた酸洗条件の制御が可能であり、
黒皮圧延の場合においても過酸洗に陥ることなく適切な
酸洗条件での酸洗が可能である。As described above, according to the present invention, it is possible to control the pickling conditions according to the change in the reduction ratio of the cold rolling of the hot-rolled steel strip by the same pickling equipment. Yes,
Even in the case of black scale rolling, it is possible to perform pickling under appropriate pickling conditions without falling into over-pickling.
【図１】 本発明に従った熱延鋼帯の酸洗ライン1 is a pickling line for a hot-rolled steel strip according to the present invention.
１、２、３：酸洗槽 ５、６、７：仕切壁 １０：
鋼帯 １１：案内ロール １５：フード Ｖ−１
〜３：バルブ Ｔ−１〜３：タンク Ｐ−１〜３：
ポンプ1, 2, 3: Pickling tank 5, 6, 7: Partition wall 10:
Steel strip 11: Guide roll 15: Hood V-1
~ 3: Valve T-1 ~ 3: Tank P-1 ~ 3:
pump
───────────────────────────────────────────────────── フロントページの続き (72)発明者 岡野 哲彦 大阪府堺市石津西町５番地 日新製鋼株式 会社堺製造所内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuhiko Okano 5th Ishizu Nishimachi, Sakai City, Osaka Inside Nisshin Steel Co., Ltd. Sakai Works
Claims (2)
下圧延する冷間圧延機の下流側で、冷間圧延の圧下率及
びラインスピードに応じて２以上の酸洗槽の内適数の槽
の液面を低下させて鋼帯を浴面上方を通過させることに
より浸漬時間を制御することを特徴とする、黒皮圧延鋼
帯の酸洗時間制御方法。1. A downstream side of a cold rolling mill for high-pressure rolling of a hot-rolled steel strip to which scale has been adhered. A method for controlling the pickling time of a black-scale rolled steel strip, wherein the immersion time is controlled by lowering the liquid level of several tanks and passing the steel strip above the bath surface.
下圧延する冷間圧延機の下流側で、２以上の複数の酸洗
槽又は２以上の複数の区画に仕切ってなる酸洗槽を設
け、各槽または仕切りごとにロールを設けて通板するよ
うに構成し、各槽の液面をそれぞれ独立に上下可能とし
て通板時に鋼板が浸漬する槽の数を、冷間圧延の圧下率
及びラインスピードに応じて制御するようにしてなるこ
とを特徴とする酸洗装置。2. A pickling bath divided into two or more plural pickling tanks or two or more plural sections on a downstream side of a cold rolling mill for rolling a hot-rolled steel strip to which scale is attached under high pressure. A tank is provided, a roll is provided for each tank or partition, and the sheet is passed through.The liquid level of each tank can be independently raised and lowered, and the number of tanks in which the steel sheet is immersed at the time of passing, the number of cold rolling. An pickling apparatus characterized in that it is controlled in accordance with a rolling reduction and a line speed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22442096A JPH1053885A (en) | 1996-08-07 | 1996-08-07 | Method for controlling pickling of cold-rolled steel strip different to rolling reduction and pickling device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22442096A JPH1053885A (en) | 1996-08-07 | 1996-08-07 | Method for controlling pickling of cold-rolled steel strip different to rolling reduction and pickling device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1053885A true JPH1053885A (en) | 1998-02-24 |
Family
ID=16813508
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22442096A Withdrawn JPH1053885A (en) | 1996-08-07 | 1996-08-07 | Method for controlling pickling of cold-rolled steel strip different to rolling reduction and pickling device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1053885A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117344312A (en) * | 2022-06-27 | 2024-01-05 | 宝山钢铁股份有限公司 | A circulation system and control method for stable oriented silicon steel pickling process |
-
1996
- 1996-08-07 JP JP22442096A patent/JPH1053885A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117344312A (en) * | 2022-06-27 | 2024-01-05 | 宝山钢铁股份有限公司 | A circulation system and control method for stable oriented silicon steel pickling process |
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