JPH02290603A - Cold rolling method for steel strip - Google Patents

Abstract

PURPOSE:To improve the width accuracy of a steel sheet after rolling and to prevent the formation of saw edges in spite of the cold high-draft rolling of the steel sheet by grinding the crumbled end faces of the steel sheet and further rolling the same after the cold rolling at a specific total draft. CONSTITUTION:Cutting tool grinders 3 is provided between tandem stand mills 5 of <=50% draft to grind the end faces of the steel sheet 1 as the measures to prevent the formation of the saw edges. The generation of the saw edges is obviated in this way even if the steel sheet is thereafter subjected to the cold rolling at >=80% total draft. In addition, the accuracy of the sheet width is improved. The complete prevention of the sheet rupture during the rolling is possible as well. As a result, the trimming of the products is omitted and the yield is improved.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、鋼帯の冷間圧延方法であって、特に、高圧下
率であっても、冷間圧延後ソーエッジの発生がなくかつ
鋼帯のミル内破断を防止でき、また幅精度の良い鋼板を
得ることができる、ソーエッジ発生を防止した鋼帯の冷
間圧延方法に関する．（従来の技術） 通常、鋼帯を冷間圧延すると、第４図に示すような鋼帯
１の幅端部ｌ゜が鋸歯状に形成されるいわゆるソーエフ
ジが発生する．かかるソーエッジは、冷間圧延前の鋼帯
端面形状が傾斜していたり、端面の加工硬化が大きいと
、冷間圧延時に端部が均一に伸延されないために生じる
ものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is a method for cold rolling steel strip, and in particular, even at a high rolling reduction rate, there is no generation of saw edges after cold rolling, and the steel strip is rolled smoothly. This article relates to a method for cold rolling steel strips that prevents the occurrence of saw edges, which can prevent the strips from breaking in the mill and produce steel plates with good width accuracy. (Prior Art) Normally, when a steel strip is cold rolled, a so-called saw edge occurs in which the width end l° of the steel strip 1 is formed into a sawtooth shape as shown in FIG. Such saw edges occur because the ends of the steel strip are not uniformly elongated during cold rolling if the shape of the end faces of the steel strip before cold rolling is inclined or if the work hardening of the end faces is large.

最近、製造工程の効率化等の観点より、高圧下圧延が実
施されるようになり、．ソーエッジがより発生しやすく
なった．ソーエッジが激しくなると、圧延中に鋼板が破
断することもある． ところで、従来は、冷間圧延前に回転剪断丸刃により鋼
板端面をトリミングし、その後冷間圧延をしていた．と
ころが、トリミングされた端面品質は、剪断加工のため
端面が加工硬化しており、またダレ、カエリがあり、端
面ば剪断面、破断面を有し傾斜している．したがって、
このまま冷間圧延すると、かえってソーエッジが発生し
易い．（発明が解決しようとする課題） このソーエッジ対策として、先に本出願人は特願昭６３
−１４６１７４号として次のような発明を堤案じた。Recently, from the perspective of improving the efficiency of the manufacturing process, high pressure rolling has been carried out. Saw edges are more likely to occur. If the saw edge becomes severe, the steel plate may break during rolling. By the way, conventionally, the end face of the steel plate was trimmed using a rotary shearing round blade before cold rolling, and then cold rolling was performed. However, the quality of the trimmed end surface is that the end surface is work hardened due to the shearing process, has sagging and burrs, and the end surface has sheared and fractured surfaces and is sloped. therefore,
If cold rolling is continued in this state, saw edges are more likely to occur. (Problem to be solved by the invention) As a countermeasure against this saw edge, the present applicant previously filed a patent application in 1983.
Tsutsumi devised the following invention as No. -146174.

「連続的に搬送される鋼帯を回転剪断丸刃にょり鋼帯の
製品幅端部の外側に所定幅より狭いトリム代が残るよう
に剪断し、その後切削バイトによって残余のトリム代を
切削することを特徴とする鋼帯のサイドトリミング方法
．」 この先行発明は、ソーエッジ防止にそれなりの効果を発
揮している． つまり、この先行発明によれば、まず、従来のように鋼
板端面をトリミング後、更に鋼板端面をバイトにより切
削することにより、加工硬化部分がなくなりソーエッジ
が防止され、また端而形状は傾斜のない矩形形状が得ら
れ、並びに微小切削のため、作業能率を下げることなく
高速切削ができる． しかしながら、その後の研究の結果、かかる方法によっ
てもソーエッジ防止は十分でなく、次のような欠点が経
験された． ■鋼板が反っていたり、耳波形状になっていると、通板
時鋼板のバタツキを完全に抑制することは困難で、バイ
トで切削しても端面が傾斜することがあり、ソーエッジ
が発生する． ■また、ほぼ矩形に端面が成形出来ても、タンデムミル
やレバースミルで、バス回数を増加し高圧下圧延するこ
とにより、鋼板の端面形状がくずれ、圧延後の幅精度が
悪くなったり、ソーエッジが発生したりする。``The continuously conveyed steel strip is sheared using a rotary shearing round blade so that a trimming margin narrower than a specified width remains on the outside of the product width end of the steel strip, and then the remaining trimming margin is cut off with a cutting tool. A method for side trimming a steel strip characterized by the following: This prior invention has shown some effectiveness in preventing saw edges. In other words, according to this prior invention, first, after trimming the end face of the steel plate as in the conventional method, the end face of the steel plate is further cut with a cutting tool, thereby eliminating the work-hardened portion and preventing saw edges, and the end face has no slope. A rectangular shape can be obtained, and because of the minute cutting, high-speed cutting is possible without reducing work efficiency. However, as a result of subsequent research, it was found that this method was not sufficient to prevent saw edges, and the following drawbacks were experienced. ■If the steel plate is warped or has an ear wave shape, it is difficult to completely suppress the flapping of the steel plate during threading, and even when cutting with a cutting tool, the end face may be inclined, resulting in saw edges. ．． ■Also, even if the end face can be formed into a nearly rectangular shape, increasing the number of baths and rolling under high pressure in a tandem mill or lever mill may distort the end face shape of the steel plate, resulting in poor width accuracy after rolling or saw edges. Occurs.

本発明は、これらの点を改善し、鋼板を冷間高圧下圧延
しても、圧延後の板幅精度が良くかつ、完全にソーエッ
ジを防止することにより歩留向上およびミル内破断を防
止する冷間圧延方法を提案することを目的としている。The present invention improves these points, and even when steel plates are cold-high-reduced, the plate width accuracy after rolling is good, and by completely preventing saw edges, it improves yield and prevents breakage in the mill. The purpose is to propose a cold rolling method.

（課題を解決するための手段） 一般に、鋼板を冷間圧延する場合、圧延機のタイプとし
て３〜６スタンドのタンデムコールドミルおよびレバー
スコールドミルがある。タンデムコールドミルは各スタ
ンドのロールを通過することにより、レバースコールド
ミルは何パスか繰り返して通仮することにより、徐々に
板厚を滅少させ所定の製品を得ている。冷間圧延時の板
輻変動やソーエッジ状況を見ると、タンデムの前後スタ
ンドやレバースミルのバス回数の少ない所、即ち低圧下
域では輻変動も少な《、ソーエッジの発生がないが、タ
ンデムの後段スタンドやレバースミルのパス回数の多い
所、即ち高圧下域で鋼板の端面形状がくずれ、幅変動が
生じたりソーエフジが発生し、時には圧延中板破断が生
じたりすることが分かった。(Means for Solving the Problems) Generally, when cold rolling a steel plate, there are three to six stand tandem cold mills and lever cold mills as types of rolling mills. Tandem cold mills pass through the rolls of each stand, while lever cold mills pass through several passes to gradually reduce the board thickness and obtain the desired product. Looking at plate radius fluctuations and saw edge conditions during cold rolling, we find that there is little radius fluctuation in the front and rear stands of the tandem and in places where the number of passes in the liver mill is low, that is, in the low reduction area. It has been found that the end face shape of the steel plate is distorted, width fluctuations occur, saw edges occur, and sometimes the plate breaks during rolling in areas where the number of passes in the lever mill is high, that is, in the high pressure area.

そこで、幅変動を防止するとともに完全にソーエフジを
防止する方法として、ある程度の冷間圧下後に、鋼板の
くずれた端面を研削により成形することが必要であると
判明した． 本発明は上記知見に基いて完成されたものである． よって、本発明の要旨とするところは、鋼帯の冷間圧延
に当り、総圧下率が５０％以上になった時点で鋼帯エッ
ジ部を少なくとも１回以上研削し、その後史に総圧下率
８０％以上で冷間圧延を行うことを特徴とする、ソーエ
ッジ発生を防止した鋼帯の冷間圧延方法である． 本発明の好適Ｃ．様によれば、前記鋼帯エノジ部は、砥
石研削および／またはバイト研削により研削される． （作用） 次に、添付図面により、本発明の作用を説明する。Therefore, it was found that as a way to prevent width fluctuations and completely prevent saw-friction, it was necessary to form the collapsed end face of the steel plate by grinding after a certain degree of cold reduction. The present invention was completed based on the above findings. Therefore, the gist of the present invention is that during cold rolling of a steel strip, the edge portion of the steel strip is ground at least once when the total rolling reduction reaches 50% or more, and thereafter the total rolling reduction is reduced. This is a method of cold rolling a steel strip, which prevents the occurrence of saw edges, and is characterized by performing cold rolling at a rolling rate of 80% or more. Preferred C. of the present invention. According to the above, the steel strip enamel portion is ground by grinding with a whetstone and/or grinding with a cutting tool. (Operation) Next, the operation of the present invention will be explained with reference to the accompanying drawings.

第１図（イ）ないし（杓に冷間圧延時の幅変動およびソ
ーエツジの発生状況を示す。Figures 1(a) to 1(a) show width fluctuations and sawing during cold rolling.

第１図（イ）は、冷間圧延前に鋼板端面を四転丸刃にて
トリミングした鋼板１を示し、符号２はトリム端面を示
す。この鋼板１をタンデムミルなりレバースミルで冷間
圧延するのであるが、以下、タンデムミルを例にとって
説明する。FIG. 1(A) shows a steel plate 1 whose end face was trimmed with a four-wheeled circular blade before cold rolling, and reference numeral 2 indicates the trimmed end face. This steel plate 1 is cold-rolled using a tandem mill or lever mill, and the explanation will be given below by taking the tandem mill as an example.

第１図（イ）の鋼板１をタンデムミルで冷間圧延する場
合、各スタンドで徐々に圧下されて最終スタンド出側で
、所定の板厚に製造される。第１図（ｎ）は、高圧下圧
延時の圧延途中の鋼板端面模式図を示すが、圧延途中で
微小のソーエッジが現れており、その後の冷間圧延によ
り更にソーエッジが助長され、第１図（ハ）のように冷
間圧延後には、ソーエッジが著しく現出している． ソーエッジが発生するのは、冷間圧延の総圧下率が８０
％以上の高圧下率域で顕著であり、そのとき鋼板の板幅
精度も±３龍と変動が大きい．この場合、第１図（＋１
）のような微小ソーエッジが発生し始めるのは、冷間圧
延の総圧下率が５０％以上の所であり、５０％未満の所
では発生していない。When the steel plate 1 shown in FIG. 1(a) is cold-rolled in a tandem mill, it is gradually rolled down at each stand and is manufactured to a predetermined thickness at the exit side of the final stand. FIG. 1(n) shows a schematic view of the end face of a steel plate during rolling at high pressure reduction. A minute saw edge appears during rolling, and the subsequent cold rolling further promotes the saw edge. As shown in (c), saw edges are clearly visible after cold rolling. Saw edges occur when the total reduction rate of cold rolling is 80
This is noticeable in the high rolling reduction range of % or more, and at that time, the width accuracy of the steel plate also fluctuates greatly, as much as ±3. In this case, in Figure 1 (+1
) The minute saw edge starts to occur when the total reduction ratio of cold rolling is 50% or more, and does not occur when the total reduction ratio of cold rolling is less than 50%.

そして、本発明にあっては、ソーエッジ防止対策として
総圧下率５０％以上のタンデムスタンドミル間に、例え
ば第２図に示すようなバイト研削装置を設け、第１図（
＝）のように鋼板端面を研削する。これにより、その後
総圧下率８０％以上に冷間圧延してもソーエッジの発生
がなく、かつ板幅精度を±ｌｍに押さえることが出来た
．第１図（ネ）は途中で研削した時の最終製品形状を示
す。In the present invention, as a measure to prevent saw edges, a cutting tool grinding device as shown in FIG.
Grind the end face of the steel plate as shown in =). As a result, even after subsequent cold rolling at a total reduction rate of 80% or more, saw edges did not occur, and the width accuracy could be kept within ±lm. FIG. 1 (N) shows the final product shape after intermediate grinding.

一方、研削タイミングを、総圧下率が５０％未満の所で
行うと、ソーエッジの抑制効果が少なく、すなわち、そ
の後の冷間圧延により、ソーエッジが発生することが分
かった． また、このときの研削量は、圧延により端面がくずれた
のを整形および微小ソーエッジを除去するため、０．５
　ｍｍ位でよいが、所望研削量、研削能率、総圧下量等
により何回か研削することも可能である。例えば、研削
一冷間圧延→研削一冷間圧延の各工程を経て行ってもよ
い。On the other hand, it was found that when the grinding timing is performed at a total reduction ratio of less than 50%, the effect of suppressing saw edges is small, that is, saw edges occur during subsequent cold rolling. In addition, the amount of grinding at this time was 0.5 in order to reshape the end face that had collapsed due to rolling and to remove minute saw edges.
It may be about mm, but it is also possible to grind several times depending on the desired grinding amount, grinding efficiency, total reduction amount, etc. For example, the process may be performed through the steps of grinding, first cold rolling, and then grinding, first cold rolling.

次に、実施例によって本発明をさらに具体的に説明する
。Next, the present invention will be explained in more detail with reference to Examples.

実施例１ 本例は、タンデムミルによる冷間圧延を行う場合を示す
。Example 1 This example shows a case where cold rolling is performed using a tandem mill.

まず、材質ＳＰＩＩＣの薄板を酸洗ラインの丸刃剪断ト
リムで３．８ｍ＋＊厚ＸＩ，５２４　＋１（−０）諺１
幅にし、次いで、その材料を５スタンドタンデムミルで
冷間圧延した． このときの冷間圧延条件を第１表にまとめて示す． 次に、タンデムミルの３号−４号スタンド間に第２図に
示す慣用のバイト研削装置３を設け、端面に０．３　ｔ
ａ研削後、更に４号、および５号スタンドにて冷間圧延
した．５号スタンド出側の製品はソーエッジが皆無で製
品寸法は０．７　ｍ＊厚ｘｉ，５２１±ｌｍ幅であった
． なお、比較材として前述の３号−４号スタンド間で端面
を研削しない点を除いて第１表の圧延条件を同じ条件で
圧延した通常の冷間圧延材を得、そのときのソーエッジ
の発生状況を観察したところ、端部に０．２鰭位のソー
エッジが見られ、製品寸法は０．　７ｍｍ　ＩｖＸ　ｌ
　．　５２１　±３曹鳳幅であった．同じく比較のため
１号−２号スタンド間に前述の本発明例のように端面の
研削を行ったところ、上記比較材と同様のソーエッジの
発生は避けられなかった。First, a thin plate of material SPIIC was cut to 3.8 m + * thickness XI, 524 +1 (-0) Proverb 1 using a round blade shear trim on the pickling line
The material was then cold rolled in a five-stand tandem mill. The cold rolling conditions at this time are summarized in Table 1. Next, a conventional tool grinding device 3 shown in Fig. 2 was installed between stands No. 3 and No. 4 of the tandem mill, and a 0.3 t.
After grinding, it was further cold rolled on stands No. 4 and No. 5. The product on the exit side of stand No. 5 had no saw edges, and the product dimensions were 0.7 m*thickness xi and 521±lm width. As a comparative material, a normal cold-rolled material was obtained which was rolled under the same rolling conditions as shown in Table 1 except that the end face was not ground between the No. 3 and No. 4 stands mentioned above, and the occurrence of saw edges was obtained. When the situation was observed, a saw edge of about 0.2 fin was observed at the end, and the product size was 0.2 fin. 7mm IvX l
．． It was 521 ±3 Cao Feng width. Similarly, for comparison, when the end face was ground between stands No. 1 and No. 2 as in the above-mentioned example of the present invention, the same saw edges as in the above-mentioned comparative material were unavoidable.

実施例２ 本例はレバースミルによる冷間圧延の例を示す。Example 2 This example shows an example of cold rolling using a liver mill.

まず、材質ＳＰＩＩＣの薄板を酸洗ラインの丸刃剪断ト
リムで４．０ｍ＋ｗ厚ＸＩ，５２４　＋１（−０）ｍ幅
にし、次いで、その材料を第３図に示すレバースミルで
冷間圧延した．このときの冷間圧延条件を第２表に示す
。First, a thin plate of material SPIIC was made into a width of 4.0 m + w thickness XI, 524 + 1 (-0) m using a round blade shear trim on a pickling line, and then the material was cold rolled in a lever mill shown in Fig. 3. The cold rolling conditions at this time are shown in Table 2.

本発明にかかる冷間圧延法として、第３図に示す慣用の
砥石研削装置４を設け、バス回数２パス後、および３バ
ス後、４パス後にも砥石にてそれぞれ端面を研削した．
研削量は合計で約０．５　ｍｍ位であった．製品の仕上
り寸法は、０．２厚ＸＩ，５２１±１幅で、ソーエッジ
が皆無であった．なお、比較材として圧延途中で砥石研
磨をしない点を除いて第２表の冷間圧延条件を同じ条件
で冷間圧延したところ、端部に２〜３龍のソーエッジが
現われ、製品寸法も０．２ｍｍ厚ＸＩ，５２１　±４１
幅であった。As the cold rolling method according to the present invention, a conventional grindstone grinding device 4 shown in FIG. 3 was installed, and the end faces were ground with the grindstone after two passes, three passes, and four passes.
The total amount of grinding was approximately 0.5 mm. The finished dimensions of the product were 0.2 thickness XI, 521±1 width, and there were no saw edges. In addition, when a comparison material was cold rolled under the same cold rolling conditions as shown in Table 2 except that no grinding wheel was applied during rolling, saw edges of 2 to 3 dragons appeared at the edges, and the product dimensions were also 0. .2mm thickness XI, 521 ±41
It was the width.

同じく比較のためパス回数１パス後に上述と同様の砥石
研磨をしたところ、比較材と同様のソーエッジの発生は
避けられなかった。Similarly, for comparison, when the same grindstone polishing as described above was performed after one pass, the same saw edges as in the comparative material were unavoidable.

第１表 第２表 （発明の効果） 本発明により、聡圧下量８０％以上という高圧下冷間圧
延してもソーエッジの発生を完全に防止出来、かつ圧延
中の板破断も完全に防止できる．また、板幅精度も飛躍
的に向上することができ、これにより、製品トリム省略
、歩留向上、等が図れるのであって、本発明の利益は大
きい。Table 1 Table 2 (Effects of the Invention) According to the present invention, it is possible to completely prevent the occurrence of saw edges even during cold rolling under a high reduction of 80% or more, and also to completely prevent plate breakage during rolling. ．． In addition, the plate width accuracy can be dramatically improved, and as a result, product trimming can be omitted, yields can be improved, etc., and the benefits of the present invention are great.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は、鋼帯のエッジ状況の説明図で、同（イ）はト
リミング後、同（口）は冷圧途中の微小ソーエッジ、同
（ハ）は製品のソーエッジ、同（二）は冷圧途中で研磨
した状況、そして同（杓はその製品状況を示す略式説明
図； 第２図は、バイト研削装置を設けたタンデムミルの圧延
ラインの概略説明図； 第３図は、砥石研削装置を設けたレバースミルの圧延ラ
インの概略説明図；および 第４図は、ソーエッジの１例を示す略式斜視図である． ■：鋼帯　　　　５：圧延ロールFigure 1 is an explanatory diagram of the edge situation of a steel strip. (A) is after trimming, (opening) is a minute saw edge during cold pressing, (c) is a saw edge of the product, and (2) is a cold pressing. A schematic explanatory diagram showing the state of polishing during rolling and the state of the product; Figure 2 is a schematic diagram of a tandem mill rolling line equipped with a bite grinding device; A schematic explanatory diagram of a rolling line of a liver mill equipped with a saw edge; and FIG. 4 is a schematic perspective view showing an example of a saw edge. ■: Steel strip 5: Rolling roll

Claims (2)

【特許請求の範囲】[Claims] （１）鋼帯の冷間圧延に当り、総圧下率が５０％以上に
なった時点で鋼帯エッジ部を少なくとも１回以上研削し
、その後更に総圧下率８０％以上で冷間圧延を行うこと
を特徴とする、ソーエッジ発生を防止した鋼帯の冷間圧
延方法。(1) When cold rolling the steel strip, grind the edge of the steel strip at least once when the total rolling reduction reaches 50% or more, and then further cold rolling at a total rolling reduction of 80% or more. A method for cold rolling a steel strip that prevents the occurrence of saw edges. （２）前記鋼帯エッジ部を、砥石研削および／またはバ
イト研削により研削する請求項１記載の鋼帯の冷間圧延
方法。(2) The method for cold rolling a steel strip according to claim 1, wherein the edge portion of the steel strip is ground by grinding with a whetstone and/or grinding with a cutting tool.