JPH0615338A - Method for preprocessing cold rolling - Google Patents

Abstract

PURPOSE:To reduce deviation of plate thickness in cold rolling caused by discoloration parts of a rolled stock by detecting the discoloration parts on the inlet side of a tandem mill and grinding the discoloration parts based on the detected result. CONSTITUTION:At first, the starting point and the end point of each discoloration part are detected by a sensor 2 to grind the discoloration part on the surface of a coil C. Positions where discoloration parts are detected and including discoloration parts and tracking and front and rear parts are ground by grinding rolls 6a at a fixed line speed. In this case, to maintain a difference in surface properties between a normal part to be small by grinding treatment, grinding is performed within the normal part of a material and its front and rear parts, and while increasing quantity of grinding gradually from the sound part toward the discoloration part, it is decreased gradually from the discoloration part toward the sound part. Thereby, change of the surface properties or change of the frictional coefficient becomes smooth and a large variation of plate thickness caused by the change of the surface properties is removed.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】この発明は、電磁鋼板用の圧延素
材などをタンデムミルに通して連続的に冷間圧延する場
合に問題となる、とくに表面変色部に起因した板厚変動
を軽減しようとするものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to reduce the plate thickness fluctuation caused by the surface discolored portion, which is a problem when continuously rolling cold rolled materials for electromagnetic steel sheets through a tandem mill. It is what

【０００２】[0002]

【従来の技術】冷間圧延時の板厚制御に関しては、従来
ＡＧＣ（Auto Gage Control)と呼ばれている種々の制御
方式が知られている。2. Description of the Related Art Conventionally, various control methods known as AGC (Auto Gage Control) are known for controlling the plate thickness during cold rolling.

【０００３】上記の板厚制御は、大別してF.F(Feed Fow
ard)方式とF.B(Feed Back)方式の２種類があり、このう
ちF.F 方式は被圧延材の板厚変動を検出してその変動分
に基づいて後段スタンドをF.F 制御しようとするもので
あり、F.B 方式は各スタンドの出側で板厚を検知し前段
スタンドをF.F 制御 (モニターＡＧＣ) したり、各スタ
ンドの入出側の板厚と板の搬送速度からスタンドの直下
における板厚を予測して、これを制御 (マスフローＡＧ
Ｃ) しようとするものである。The above plate thickness control is roughly classified into FF (Feed Fow).
ard) method and FB (Feed Back) method. Of these, the FF method detects the plate thickness variation of the material to be rolled and tries to FF control the post stand based on the variation. The FB method detects the plate thickness on the exit side of each stand and controls the front stand by FF (monitor AGC), or predicts the plate thickness immediately below the stand from the plate thickness on the entrance and exit sides of each stand and the plate transport speed. , Control this (Massflow AG
C) It is what you are trying to do.

【０００４】[0004]

【発明が解決しようとする課題】上記の技術によれば、
冷間圧延時の板厚変動は極めて小さなものとすることが
できたが、とくに、冷間圧延に先立って実施される酸洗
処理等で素材の表面に変色した領域が生じている場合に
は、それを残存させたまま圧延すると、上記の制御を行
っても板厚変動は避けられず、その領域における圧下条
件の急変によってはしばしば板の破断等のトラブルを起
こすこともあった。According to the above technique,
The plate thickness variation during cold rolling could be made extremely small, but especially when there is a discolored area on the surface of the material due to pickling treatment performed prior to cold rolling. However, if the steel sheet is rolled while it remains, fluctuations in the sheet thickness cannot be avoided even if the above control is performed, and troubles such as sheet breakage often occur due to sudden changes in the rolling conditions in that region.

【０００５】素材の表面における変色は、正常な酸洗処
理を施したものに比べ板の表面にFe ₂O₃ やFeO 等の酸化
物が大量に残存、又は発生したものであって、これは酸
洗ラインでの操業トラブルによる酸洗過多、酸洗不足、
塩酸の残存あるいはスプレー水による発錆等が主な原因
であり、このような領域 (１〜50ｍの範囲で点在) は表
面性状の急激な変化( 表面に存在する酸化物等が潤滑材
の働きをするため圧延時の摩擦係数を大きく変化させ
る) をもたらし、板厚の変動状況を検出して制御を行う
従来の技術では以下の理由から対応し得なかったのであ
る。Discoloration on the surface of the material is caused by normal pickling
Fe on the surface of the plate compared to ₂O₃Oxidation of FeO, etc.
A large amount of residual or generated substances, which are acid
Excessive pickling, insufficient pickling due to operational problems in the washing line,
Main causes are residual hydrochloric acid or rust caused by spray water
And such areas (scattered in the range of 1 to 50 m) are shown in the table.
Sudden change in surface properties (oxides present on the surface are lubricants
To change the friction coefficient during rolling
Control) by detecting the variation of plate thickness.
The conventional technology could not handle it for the following reasons.
It

【０００６】すなわち、変色部の板厚は正常領域の板厚
と同じであること、また、第１パスで板厚変動が発生し
た際にこれをたとえばF.B 制御で修正しようとしても変
化が急峻すぎ (短い領域でかつ変動量が大きい) 応答が
不可能であること。That is, the plate thickness of the discolored portion is the same as the plate thickness in the normal region, and when a plate thickness variation occurs in the first pass, even if it is attempted to correct it by FB control, the variation is too steep. (It is a short region and the amount of fluctuation is large) The response is impossible.

【０００７】板の変色に関しては、酸洗処理で対処する
ことも考えられるが、この工程で板の変色を皆無にする
ことは現在のところ困難であり、また、冷間圧延にてこ
の種の板厚変動を防止する有効な手立てについては何も
なく、このため通常は変色部の存在する領域を除く圧延
を行っていて、圧延効率の低下が避けられず、また、変
色部のスクラップ化による歩留りの低下も避けられない
不利があった。Regarding the discoloration of the plate, it may be considered to deal with the pickling treatment, but it is difficult at present to eliminate the discoloration of the plate in this step, and the cold-rolling of this kind is also considered. There is no effective way to prevent the plate thickness fluctuation, so rolling is usually performed excluding the area where the discolored part exists, and the reduction of rolling efficiency cannot be avoided, and the discolored part is scrapped. There was also an unavoidable disadvantage in yield reduction.

【０００８】この発明の目的は、上述したような板の変
色部に起因した冷間圧延での板厚変動を軽減できる方法
を提案するところにある。An object of the present invention is to propose a method capable of reducing the plate thickness variation in cold rolling due to the discolored portion of the plate as described above.

【０００９】[0009]

【課題を解決するための手段】板の表面に変色部を有す
るものの冷間圧延では、圧延時のその部分における摩擦
係数の低下や荷重の急激な低下、先進率の低下は確認さ
れているが、板厚や変形抵抗は正常な領域と変わらな
い。[Means for Solving the Problems] Although cold-rolling has a discolored portion on the surface of the plate, it has been confirmed that the reduction of the friction coefficient, the rapid reduction of the load and the reduction of the advance rate at that portion during rolling are confirmed. The plate thickness and deformation resistance are the same as those in the normal area.

【００１０】このため、この発明では、冷間圧延に先立
って、変色部を構成するFeO 等の酸化物を除去すべく下
記の如き要領に従って研磨処理を施すことによって所期
した目的を達成したものである。Therefore, according to the present invention, prior to cold rolling, the intended purpose is achieved by performing a polishing treatment according to the following procedure to remove oxides such as FeO constituting the discolored portion. Is.

【００１１】すなわち、この発明は、被圧延材をタンデ
ムミルに通して冷間圧延する際、タンデムミルの入側に
て、圧延素材の表面性状の変化に由来した変色部を検知
し、この検知結果に基づいて該変色部に研磨処理を施す
ことを特徴とする冷間圧延の前処理方法である。That is, according to the present invention, when a material to be rolled is passed through a tandem mill and cold-rolled, a discolored portion resulting from a change in surface texture of the rolled material is detected on the inlet side of the tandem mill, and this detection is performed. A pretreatment method for cold rolling, which comprises subjecting the discolored portion to a polishing treatment based on the result.

【００１２】上記の研磨処理は、圧延条件の急峻な変化
を回避するため、被圧延材の変色部とこれを前後に挟む
健全部の範囲において行い、かつ健全部から変色部に向
けて研磨量を漸増させる一方、変色部から健全部に向け
て研磨量を漸減させるようにするのがとくに好ましい。In order to avoid a sharp change in rolling conditions, the above polishing treatment is performed in the range of the discolored part of the material to be rolled and the sound part sandwiching the discolored part in front and back, and the polishing amount from the sound part to the discolored part. It is particularly preferable that the polishing amount be gradually increased from the discolored portion to the sound portion while the polishing amount is gradually increased.

【００１３】さて、図１にこの発明を実施するのに用い
て好適な前処理設備の構成を示す。図における番号１は
コイルの巻戻し機、２は巻戻し機１により巻戻されたコ
イルＣの変色部を検知するセンサー (測色計) 、３は第
１段ブライドルロール、４はルーパー、５は第２段ブラ
イドルロール、Now, FIG. 1 shows a configuration of a pretreatment facility suitable for carrying out the present invention. In the figure, reference numeral 1 is a coil rewinding machine, 2 is a sensor (colorimeter) for detecting a discolored portion of the coil C rewound by the rewinding machine 1, 3 is a first stage bridle roll, 4 is a looper, 5 Is the second stage bridle roll,

【００１４】６はコイルＣの表面変色部を研磨除去する
ための研磨装置であって、この装置６は図２にその詳細
を示す如く、研削ゾーン６Ａとリンスゾーン６Ｂおよび
ドライヤーゾーン６Ｃからなり、このうち、研削ゾーン
６Ａには研削ロール６ａ₁ とスプレーノズル６ａ₂ が、
リンスゾーン６Ｂにはリンガーロール６ｂが、またドラ
イヤーゾーン６Ｃにはドライヤー６ｃがそれぞれ配置さ
れている。Reference numeral 6 denotes a polishing device for polishing and removing the surface discolored portion of the coil C. This device 6 comprises a grinding zone 6A, a rinsing zone 6B and a dryer zone 6C, as shown in detail in FIG. Of these, in the grinding zone 6A, the grinding roll 6a ₁ and the spray nozzle 6a ₂
A ringer roll 6b is arranged in the rinse zone 6B, and a dryer 6c is arranged in the dryer zone 6C.

【００１５】また、７はセンサー２の検知結果に基づい
て研削ロール６ａ₁ を適切に作動させる演算制御装置、
８は第３段ブライドルロール、９は４段形式を例として
示した冷間圧延用タンデムミル、そして10は圧延を終え
たコイルＣを巻取る巻取り機である。Reference numeral 7 is an arithmetic and control unit for appropriately operating the grinding roll 6a ₁ based on the detection result of the sensor 2.
Reference numeral 8 is a third-stage bridle roll, 9 is a tandem mill for cold rolling, which is shown as an example of a 4-stage type, and 10 is a winder for winding the rolled coil C.

【００１６】上記の構成になる設備にてコイルＣの表面
の変色部を研削処理するには、まずセンサー２にて変色
部の開始点および終了点を検知する。To grind the discolored portion on the surface of the coil C with the equipment having the above-described structure, first, the sensor 2 detects the start point and the end point of the discolored portion.

【００１７】そして、変色部を検知した位置をトラッキ
ングし、変色部を含むその前後にわたりライン速度一定
の状態にて研削ロール６ａ₁ による研削処理を施す (正
常部から変色部へ向けて研削量を徐々に大きくしてい
き、変色部では研削量一定に、さらにここから正常部へ
向けて研削量を徐々に小さくなるような研削処理) 。図
３に、コイルＣの長手方向に沿って20ｍの変色部があっ
て、これに研磨処理を施す場合の研削ロール６ａ₁ 動
力、研削量および中心線平均粗さ (Ｒ_a ) の変動状況を
示す。Then, the position where the discolored portion is detected is tracked, and the grinding process is performed by the grinding roll 6a ₁ at a constant line speed before and after the discolored portion (the amount of grinding is changed from the normal portion to the discolored portion). Grinding process that gradually increases the grinding amount so that the amount of grinding is constant in the discolored area and gradually decreases from here to the normal area). In FIG. 3, there is a discolored portion of 20 m along the longitudinal direction of the coil C, and the variation of the power of the grinding roll 6a ₁ , the amount of grinding and the center line average roughness (R _a ) when the polishing treatment is performed on the discolored portion. Show.

【００１８】[0018]

【作用】冷間圧延時の板幅変動の原因となる変色部は、
板の表面に多量の酸化物が残存することが原因であっ
て、これが圧延時に潤滑材の役目を果たすため摩擦係数
の急激な低下や圧延荷重の低下、先進率の低下をもたら
すことは先にも述べた通りであり、この部分は第１スタ
ンドで大きな板厚変動となり、第２スタンド以降でのＡ
ＧＣによる板厚修正能力をはるかに越えるため、圧延終
了後においても板厚変動がそのまま残りこれが著しい場
合にはオフゲージとなっていたのである。[Function] The discolored portion that causes the variation in strip width during cold rolling is
This is due to the large amount of oxides remaining on the surface of the plate, which plays the role of a lubricant during rolling, leading to a sharp decrease in the friction coefficient, rolling load and advance rate. As described above, this part has a large plate thickness variation at the first stand, and
Since the sheet thickness correction ability by GC is far exceeded, the sheet thickness variation remained as it was even after the rolling was finished, and when it was remarkable, it was off gauge.

【００１９】この発明では、被圧延材の冷間圧延に先立
ち、その入側にて、変色部を研削除去するようにしたの
で、圧延時における摩擦係数は被圧延材の長手方向に沿
ってほぼ安定したものとなるので、変色部に起因した板
幅変動は極めて小さなものとなる。In the present invention, prior to the cold rolling of the material to be rolled, the discolored portion is ground and removed on the entry side thereof, so that the friction coefficient during rolling is almost equal to the longitudinal direction of the material to be rolled. Since it is stable, the plate width variation caused by the discolored portion is extremely small.

【００２０】被圧延材の研削処理に当たっては、研削処
理を施した部分と正常部との表面性状 (表面粗度) がな
るべく同等になるようにする必要がある。その理由は、
表面粗度が製品品質に大きな影響を与えるような、たと
えば電磁鋼板の如きにおいては製品規格においても差
(酸洗処理時の板表面の粗さＲ_a ＝0.7 〜2.0 μm ) が
あり、この差があまり大きくなると圧延条件の急峻な変
化によって却って板厚変動を起こしやすくなるからであ
る。酸洗時における粗さＲ_a が0.7 〜2.0 μm になる場
合おいてはその平均値としてＲ_a ＝1.2 ±0.2 μm 程度
とするのが好ましい。In the grinding treatment of the material to be rolled, it is necessary to make the surface properties (surface roughness) of the ground portion and the normal portion as equal as possible. The reason is,
Differences in product specifications, such as electrical steel sheets, where surface roughness has a large effect on product quality.
(Roughness of plate surface during pickling treatment R _a = 0.7 to 2.0 μm), and if this difference is too large, a steep change in rolling conditions tends to cause plate thickness fluctuations. Roughness during pickling R _a is preferably in the R _a = 1.2 ± 0.2 μm about a 0.7 to 2.0 is at may become [mu] m average value.

【００２１】研磨処理による正常部との表面性状の差が
大きくならないようにするためには、被圧延材の変色部
とこれを前後に挟む正常部の範囲、たとえばタンデムミ
ルの第１スタンドの出側センサで検出した検出値に基づ
いてF.B 制御ができるような長さ (変色部の前後の20〜
50ｍ程度) の範囲内において行い、かつ健全部から変色
部に向けて研磨量を漸増させる一方、変色部から健全部
に向けて研磨量を漸減させるようにするのがよく、これ
によれば表面性状の変化 (摩擦係数の変化) が滑らかに
なり、表面性状の変化に起因した大きな板厚変動はほと
んどなくなる。また、この領域は、表面性状が局部的に
は異なるけれども滑らかに変化しているので、通常のF.
B 方式による板厚制御の適用にて、より高い板厚制御を
行うこともできる。In order to prevent the difference in surface texture from the normal portion due to the polishing treatment from increasing, the range of the discolored portion of the rolled material and the normal portion sandwiching the discolored portion, for example, the first stand of the tandem mill is exposed. The length that allows FB control based on the detection value detected by the side sensor (20 ~
It is good practice to perform the polishing within a range of about 50 m) and gradually increase the polishing amount from the healthy part to the discolored part, while gradually decreasing the polishing amount from the discolored part to the healthy part. Changes in properties (changes in friction coefficient) become smooth, and large plate thickness fluctuations due to changes in surface properties are almost eliminated. In addition, although the surface texture is locally different in this area, it changes smoothly, so that the normal F.
It is also possible to perform higher plate thickness control by applying plate thickness control by method B.

【００２２】被圧延材の表面の変色部を検知するセンサ
ーは、とくに限定されないが、特開平1-216222号公報に
開示されている装置や特開平4-128636号公報に開示の技
術が適用できる。The sensor for detecting the discolored portion on the surface of the material to be rolled is not particularly limited, but the device disclosed in Japanese Patent Application Laid-Open No. 1-216222 and the technology disclosed in Japanese Patent Application Laid-Open No. 4-128636 can be applied. .

【００２３】この発明の適用下に冷間圧延を施す場合に
用いて好適な素材は、とくに圧延前の処理工程との関係
で部分的な酸化変色などを生じやすい、軟鋼、低合金
鋼、珪素鋼などであるが、他の金属薄板の冷間圧延にも
ひろく適用できる。Suitable materials for use in cold rolling under the application of the present invention are mild steel, low alloy steel, and silicon, which are liable to cause partial oxidative discoloration particularly in relation to the treatment process before rolling. Although it is steel, etc., it can be widely applied to cold rolling of other thin metal plates.

【００２４】[0024]

【実施例】幅1000mm, 厚さ2.3 mmになる酸洗処理済の電
磁鋼板用のコイル (成分組成：Ｃ：0.003 ％、Si : 0.1
50％、Mn : 0.200％、Ｐ：0.080 ％、Ｓ：0.003 ％）を
適用して、その表裏面での変色部を検知できる汎用測色
計 (サンプリングピッチ：100 ms) を備え研削ゾーンに
研削動力が最大100kw/片側になる弾性砥石ロール (＃36
番) を配置した上掲図１に示した設備にて、上掲図３に
示したような条件下で研削処理を施し、これに続く冷間
圧延にて板厚0.5 mmに仕上げた場合における板厚の変動
状況について調査した。[Example] A coil for a magnetic steel sheet having a width of 1000 mm and a thickness of 2.3 mm, which has been subjected to pickling treatment (composition composition: C: 0.003%, Si: 0.1
50%, Mn: 0.200%, P: 0.080%, S: 0.003%), and equipped with a general-purpose colorimeter (sampling pitch: 100 ms) that can detect discolored areas on the front and back sides of the grinding zone. Elastic whetstone roll with power up to 100kw / one side (# 36
No.) is installed in the equipment shown in FIG. 1 above, and is ground under the conditions shown in FIG. 3 above, and then cold rolled to finish the sheet thickness to 0.5 mm. The variation of the plate thickness was investigated.

【００２５】その状況及び結果を、冷間圧延に先立って
研削処理を施さなかった他はすべて同等の条件で圧延を
行った場合と比較して図４に示す。The situation and the results are shown in FIG. 4 in comparison with the case where the rolling was performed under the same conditions except that the grinding treatment was not performed prior to the cold rolling.

【００２６】図４より明らかなように、この発明に従う
操業を行った適合例では第１スタンド出側の板厚偏差は
もとより、最終スタンド出側の板厚偏差も極めて軽減
(適合例では約７μm 程度であったのに対して比較例で
は約32μm ) され正常部と全く遜色ないことが確認でき
た。また、適合例では、変色部を除く操作は必要ないの
で操業能率は通常の圧延の処理量に比較して2.2 t/hr程
度増加することができ、歩留りについても0.08％程度向
上させることができた。As is apparent from FIG. 4, in the adapted example in which the operation according to the present invention is performed, not only the deviation of the plate thickness on the delivery side of the first stand but also the deviation of the sheet thickness on the delivery side of the final stand is significantly reduced.
(Comparative example was about 7 μm, while Comparative example was about 32 μm) and it was confirmed that it was no different from the normal part. Also, in the conforming example, since the operation excluding the discolored part is not necessary, the operating efficiency can be increased by about 2.2 t / hr compared to the throughput of normal rolling, and the yield can be improved by about 0.08%. It was

【００２７】[0027]

【発明の効果】この発明によれば、被圧延材表面の変色
部に起因した冷間圧延での板厚変動を軽減できるので不
良部分が少なく、変色部を避けながら圧延を行う必要が
ないので操業効率も著しく改善することができた。According to the present invention, the variation in plate thickness in cold rolling due to the discolored portion of the surface of the material to be rolled can be reduced, so that there are few defective portions and it is not necessary to perform rolling while avoiding the discolored portion. The operational efficiency was also significantly improved.

【図面の簡単な説明】[Brief description of drawings]

【図１】この発明を実施するのに用いて好適な設備の構
成説明図である。FIG. 1 is a structural explanatory view of equipment suitable for carrying out the present invention.

【図２】図１の要部を示した図である。FIG. 2 is a diagram showing a main part of FIG.

【図３】この発明に従う研削要領を示した図である。FIG. 3 is a diagram showing a grinding procedure according to the present invention.

【図４】実施例での圧延状況を示した図である。FIG. 4 is a diagram showing a rolling situation in an example.

【符号の説明】[Explanation of symbols]

１ コイルの巻戻し機 ２ センサー ３ 第１段ブライドルロール ４ ルーパー ５ 第２段ブライドルロール ６ 研削装置 ７ 演算制御装置 ８ 第３段ブライドルロール ９ 冷間圧延用タンデムミル 10 巻取り機 1 Coil Rewinder 2 Sensor 3 1st Stage Bridle Roll 4 Looper 5 2nd Stage Bridle Roll 6 Grinding Device 7 Arithmetic Control Device 8 3rd Stage Bridle Roll 9 Cold Rolling Tandem Mill 10 Winder

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 被圧延材をタンデムミルに通して冷間圧
延する際、タンデムミルの入側にて、圧延素材の表面性
状の変化に由来した変色部を検知し、この検知結果に基
づいて該変色部に研磨処理を施すことを特徴とする冷間
圧延の前処理方法。1. When a material to be rolled is cold-rolled through a tandem mill, a discolored portion caused by a change in surface texture of the rolled material is detected on the inlet side of the tandem mill, and based on the detection result. A pretreatment method for cold rolling, which comprises subjecting the discolored portion to a polishing treatment. 【請求項２】 研磨処理は、被圧延材の変色部とこれを
前後に挟む健全部の範囲において行い、かつ健全部から
変色部に向けて研磨量を漸増させる一方、変色部から健
全部に向けて研磨量を漸減させるものである請求項１記
載の方法。2. The polishing treatment is performed within a range of a discolored part of a material to be rolled and a sound part sandwiching the discolored part in front and back, and the polishing amount is gradually increased from the sound part to the discolored part while the discolored part is changed to the sound part. The method according to claim 1, wherein the polishing amount is gradually reduced toward the end.