JPS62161919A - Manufacture of hard sheet steel for can excellent in drawability and minimized in anisotropy - Google Patents

Abstract

PURPOSE:To obtain the titled sheet steel for cans reduced in ear rate, free from rough surface, and good in quality, by specifying steel-plate components, slab-heating temp., finishing temp. of hot rolling and winding temp. among hot rolling temps., continuous annealing conditions, and cold draft. CONSTITUTION:A continuously cast slab consisting of 0.04-0.09% C, <=0.02% Si, <=0.4% Mn, <=0.03% P, <=0.02% S, 0.010-0.050% Al, <=0.01% N, and the balance Fe and satisfying 0.05<N/Al<0.3 is hot-rolled into hot-rolled coil. At this time, extraction temp. of slab from a heating furnace, finishing temp. of rolling, and winding temp. are regulated to 1,100-1,200 deg.C, a temp. at and above the Ar3 transformation temp., and a temp. lower than 300N/Al+610( deg.C) and higher than 300N/Al+520( deg.C), respectively. The above coil is pickled, cold- rolled at 85-93% draft, and successively subjected to recrystallization annealing at 720-650 deg.C right under the A1 transformation temp. by a continuous annealing method and further to temper rolling at 0.5-2.0% draft.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、硬質かつ絞り加工性に優れる異方性の小さい
缶用薄鋼板の製造方法に、関し、特に本発明は、ＤＲＤ
缶用素材のうち連続焼なましが施され、かつ眺質度の比
較的高いＴＡＣＡ材、　ＴＳＣＡ材およびＴ６０Ａ材で
ある硬質薄鋼板の製造方法に関するものである。Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a thin steel sheet for cans that is hard, has excellent drawing workability, and has low anisotropy.
The present invention relates to a method for producing hard thin steel sheets such as TACA material, TSCA material, and T60A material, which are continuously annealed among materials for cans and have relatively high visual quality.

（従来の技術） プレス成形により胴部と地部を一体成形したカップに天
部を接合したいわゆる２ピ一ス缶が食缶として広く用い
られている。従来２ピ一ス缶には箱焼鈍により仕上げら
れた調質度がＴＩ　−Ｔ３の軟質材が使用されていた。(Prior Art) So-called two-piece cans, in which the top is joined to a cup whose body and base are integrally molded by press molding, are widely used as food cans. Conventionally, a soft material finished by box annealing and having a heat refining degree of TI-T3 has been used for two-piece cans.

しかし、２ピ一ス缶用製缶機の改良はめざましく、製缶
能率の大きい製缶機が出現したことにより、ＤＲＤ缶（
Ｄｒａｗｎ　ａｎｄ　Ｒｅｃｌｒａｗｎ　Ｃａｎ　）が
急速に使用されるようになっており、かかるＤＲＤ缶に
は調質度Ｔ４およびＴ５材が使われるようになっている
。しかし生産量の増大に伴って、良品歩Ｉ）まりがます
ます問題にされるようになり、良品歩止まりが大きくな
るような素材が強く要求されるようになった。However, improvements in can-making machines for 2-piece cans have been remarkable, and with the advent of can-making machines with high can-making efficiency, DRD cans (
Drawn and recrawn cans are rapidly becoming used, and such DRD cans are made of tempered T4 and T5 materials. However, with the increase in production, the yield rate of quality products has become more and more of a problem, and there has been a strong demand for materials that can increase the yield rate of quality products.

一般にＤＲＤ缶用素材として使用される薄鋼板の絞り加
工性は自動車の車体などに用いられる絞り加工用冷延鋼
板と同様に一般的にはｒ値が大きいことが望ましいとさ
れている。しかし大きい深絞９加工を必要とする薄鋼板
は、たとえｒ値が大きくても鋼板が薄いため絞り加工に
おいてしわが発生しやすく、高度の深絞抄加工を施すこ
とが難しいため、深い缶を製作する場合には再絞りが併
用されるので、実際にはあまり大きいｒ値を有する材料
は要求されず、むしろトリミング化を小さくして良品歩
止まりを向上させるために容器フランジ部の耳発生の少
ないいわゆるｒ値の面内異方性（Δｒ）の小さい薄鋼板
が要求されている。It is generally considered desirable that the drawability of a thin steel sheet used as a material for DRD cans be large, as is the case with cold-rolled steel sheets for drawing used for automobile bodies and the like. However, thin steel sheets that require large deep drawing 9 processing are easy to wrinkle during drawing because they are thin even if the r value is large, and it is difficult to perform deep drawing processing. Since re-drawing is also used in manufacturing, materials with a very large r value are not actually required.In fact, in order to reduce trimming and improve the yield of good products, it is necessary to reduce the occurrence of ears at the container flange. There is a demand for thin steel sheets with a small in-plane anisotropy (Δr) and a small so-called r value.

ところで、前記ｒ値は、薄鋼板の深絞り加工性を示す一
つの指標として用いられており、この値は引張試験にお
ける幅方向の歪に対する厚さ方向の歪の比で示される値
である。このｒ値は引張り試験片の採取方向によって異
なり、低炭素Ａｌ　キルド鋼冷延鋼板にあっては圧延方
向に対して９０゜の方向に採取したものが最も大きく、
次いでＯ０方向が高く、４５°方向が最も小さいという
異方性を有するものが多く、またこの異方性の程度は鋼
板の製造方法によって異なる。一方絞り加工後の缶フラ
ンジ部は円周方向の板厚分布と高さに異方性が現われる
。従ってｒ値が大きい方向に缶の耳の山部が高くなり、
一方ｒ値の小さい方向に缶の耳の谷部が低くなる。耳の
高さは加工条件によっても異なるが、薄鋼板のΔｒの大
きいものほど大きい耳となるので、このような鋼板を用
いると材料歩止まりが低下する。By the way, the r value is used as an index indicating the deep drawing workability of a thin steel plate, and this value is a value indicated by the ratio of the strain in the thickness direction to the strain in the width direction in a tensile test. This r value varies depending on the direction in which the tensile test piece is taken, and for low carbon Al killed cold rolled steel sheets, the r value is largest when the specimen is taken in a direction of 90° to the rolling direction.
Most of the steel sheets have anisotropy that is highest in the O0 direction and lowest in the 45° direction, and the degree of this anisotropy varies depending on the manufacturing method of the steel sheet. On the other hand, anisotropy appears in the circumferential thickness distribution and height of the can flange after drawing. Therefore, as the r value increases, the peak of the can's edge becomes higher.
On the other hand, as the r value decreases, the trough of the can edge becomes lower. Although the height of the lugs varies depending on the processing conditions, the larger the Δr of the thin steel sheet, the larger the lugs, so when such a steel plate is used, the material yield decreases.

ところで、ｒ値は鋼板の結晶集合組織と密接な関係があ
り、従ってΔτ値も同様に結晶集合組織と密接な関係が
あり、このΔτ値は（１１冷間圧延の圧下率、（２）冷
延前の熱間圧延温度、　（３）　ＡｔＮなどの析出物の
再結晶過程における析出挙動や分散状態により大きく変
化することが知られている。By the way, the r value has a close relationship with the crystal texture of the steel sheet, and therefore the Δτ value also has a close relationship with the crystal texture. It is known that the hot rolling temperature before rolling (3) greatly changes depending on the precipitation behavior and dispersion state of precipitates such as AtN in the recrystallization process.

このことから製缶用金型の工夫に合せてΔｒの小さい極
薄鋼板を用いることにより容器フランジ部の耳発生を最
小限に改善することができる。しかし一般にΔｒの小さ
い極薄鋼板はｒ値が悪くなり、深絞り加工そのものを阻
害する欠点もある。From this, by using an ultra-thin steel plate with a small Δr in conjunction with the design of can-making molds, it is possible to minimize the occurrence of selvage at the container flange. However, in general, ultrathin steel sheets with a small Δr have a poor r value, which also has the disadvantage of inhibiting deep drawing itself.

本発明者らは先に特開昭５８−１５１４２６号により従
前の方法の欠点を改善し、絞り加工性に優れた、すなわ
ちｒ値が大きく、かつΔｒの小さい面内実方性の小さい
缶用ＤＲ極薄鋼板の製造方法を開示した。元来Ａｔキル
ド連続鋳造鋼片は冷間圧延性が悪く、特に極薄鋼板を得
るために高圧下率圧延を行なう場合には、スリップ現象
やチャタリング現象が発生し、不良率が大きくなり、あ
るいはストリップの冷間圧延中破断が生起するという問
題点があったが、上記本発明者らが開示した方法によれ
ば固溶Ｎを少なくすることにより前記問題点を解決して
冷間圧延性を大幅に向上させることができだ。すなわち
前記方法によれば、所定の成分組成を有する連続鋳造鋼
片を従来の加熱炉内でＡｔとＮを分解固溶させる処理を
行なわず、前記鋼片を低温に加熱保持し、熱間圧延後の
銅帯の巻取り温度を高くして、固溶Ｎ量の少ない熱延鋼
帯を得た後酸洗いし、次に圧下率８０〜９５％で第１回
冷間圧延を、再結晶焼鈍を、圧下率１０〜３０％で第２
回冷間圧延を順次施すことにより硬質かつ絞り加工性の
優れた面内異方性の小さい缶用極薄−板を得ることがで
きた。The present inventors have previously improved the drawbacks of the previous method in JP-A No. 58-151426, and developed a DR for cans that has excellent drawing workability, that is, a large r value and a small in-plane realisotropy. A method for manufacturing ultra-thin steel sheets has been disclosed. Originally, At-killed continuous cast steel slabs have poor cold rolling properties, and especially when high reduction rate rolling is performed to obtain ultra-thin steel sheets, slipping and chattering phenomena occur, increasing the defective rate, or There was a problem in that the strip broke during cold rolling, but according to the method disclosed by the present inventors, this problem was solved by reducing the solid solution N, and the cold rolling property was improved. It can be improved significantly. That is, according to the above method, a continuously cast steel billet having a predetermined component composition is heated and held at a low temperature without performing a treatment for decomposing At and N into a solid solution in a conventional heating furnace, and then hot rolling. The coiling temperature of the subsequent copper strip is increased to obtain a hot-rolled steel strip with a low amount of solute N, which is then pickled, followed by the first cold rolling at a reduction rate of 80 to 95%, followed by recrystallization. The second annealing is performed at a reduction rate of 10 to 30%.
By sequentially performing cold rolling, it was possible to obtain an ultra-thin sheet for cans that was hard, had excellent drawing workability, and had small in-plane anisotropy.

本発明者らは、前記特開昭５８−１５１４２６号記載の
発明に引続いて、鋭意研究を重ねた結果さらに良品質の
缶用薄鋼板を低コストで製造することのできる方法に想
到し、本発明を完成した。Following the invention described in JP-A No. 58-151426, the present inventors have conducted extensive research and have come up with a method that can produce thin steel sheets for cans of even better quality at a lower cost. The invention has been completed.

（問題点を解決するための手段） 本発明は、本発明者らが先に提案した前記特開昭５８−
１５１４２６号記載の発明をさらに改良して耳率の小さ
い、肌荒れのない良品質の缶用薄鋼板の製造方法を提供
することを目的とするものであって、特許請求の範囲記
載の方法を提供することによって前記目的を達成するこ
とができる。−ｔなわち本発明は、Ｇ　０．０４〜０．
０９％、　Ｓｉ　０．０２％以下。(Means for Solving the Problems) The present invention is based on the above-mentioned Japanese Patent Application Laid-Open No.
It is an object of the present invention to further improve the invention described in No. 151426 to provide a method for producing a high-quality thin steel sheet for cans with a small selvage ratio and no rough skin, and to provide the method described in the claims. By doing so, the above objective can be achieved. -t, that is, in the present invention, G 0.04 to 0.
09%, Si 0.02% or less.

Ｍｎ０．４％以下、　Ｐ　０．０３％以下＋　Ｓ　０．
０２％以下。Mn 0.4% or less, P 0.03% or less + S 0.
0.2% or less.

Ａｔ０．０１０〜０．０５０％、　Ｎ　０．０１％以下
そして０．０５Ｎ ＜　ＴＺ　＜　０．３１残部Ｆｅおよび不可避的不純物
よりなる連続鋳造鋼片に熱間圧延を施す際の鋼片の加熱
炉よりの抽出温度を１１００〜１２００℃に、熱間圧延
仕上温度をＡｒ５変態点温度以上に、巻取り温度Ｎ　　
　　　　　　　　　　　　　　　　　　　　　Ｎを３０
０−　＋　６１０より低温で、３００−Ｈ＋　５２０よ
りＡｔ 高温の範囲で行い熱延鋼帯となし、次に酸洗後圧下″４
８５〜９３％で冷間圧延を、連続焼鈍法によりＡ１変態
点温度の直下である７２０〜６５０℃の温度で再結晶焼
鈍を、さらに圧下率０．５〜２．０％で調質圧延を順次
施すことを特徴とする硬質かつ絞り加工性に優れる面内
異方性の小さい缶用薄鋼板の製造方法に関するものであ
る。A heating furnace for hot rolling a continuously cast steel billet consisting of At 0.010 to 0.050%, N 0.01% or less, and 0.05N < TZ < 0.31 balance Fe and unavoidable impurities. The extraction temperature is set at 1100-1200°C, the hot rolling finishing temperature is set at Ar5 transformation point temperature or higher, and the winding temperature is set at N.
N to 30
It is made into a hot-rolled steel strip at a temperature lower than 0- + 610 and at a higher temperature than 300-H + 520, and then reduced after pickling to ``4''.
Cold rolling at 85-93%, recrystallization annealing at a temperature of 720-650°C, which is just below the A1 transformation point temperature, by continuous annealing, and skin pass rolling at a rolling reduction of 0.5-2.0%. The present invention relates to a method for manufacturing a thin steel sheet for cans, which is hard, has excellent drawing workability, and has small in-plane anisotropy, which is characterized by sequential application.

本発明者らは、ｒ値が大きくてΔｒの小さいＴ４゜Ｔ５
．Ｔ６に相当する薄鋼板を製造するために、集合組織に
影響を及ぼすと考えられる（１）ｗ４板成分。The present inventors found that T4°T5 has a large r value and a small Δr.
．． In order to manufacture a thin steel sheet equivalent to T6, (1) W4 sheet component is considered to have an effect on the texture.

（２）鋼片加熱温度、（３）熱間圧延温度中の熱延仕上
温度（この温度を以下ＦＴと称す）および巻取り温度（
この温度を以下ＣＴと称す）、（４）連続焼鈍条件、お
よび（５）冷間圧下率の全工程にわたって鋭意研究を重
ねた結果、以下に述べる現像を知見した。(2) billet heating temperature, (3) hot rolling finishing temperature (hereinafter referred to as FT) during hot rolling temperature and coiling temperature (
This temperature is hereinafter referred to as CT), (4) continuous annealing conditions, and (5) cold rolling reduction ratio throughout the entire process, and as a result, the development described below was discovered.

次に本発明の詳細な説明する。Next, the present invention will be explained in detail.

通常のＡｔキルド鋼板の製造方法によれば、鋼片加熱温
度は鋼片中のＡｔＮをＡｔとＮとに分解させるため１２
００℃より高い温度で加熱−均熱した後に鋼片は加熱炉
から抽出される。これに対して、本発明によれば、従来
の加熱炉内でＡｔとＮを分解同浴させる処理を施さずに
、鋼片を低温に加熱保持し、かつ熱間圧延後の銅帯の巻
取り温度（℃Ｔ）をＨ／Ａｔの比に応じて高温となすこ
とにより、固溶Ｎ景の少ない熱延鋼帯を経済的に得るこ
とができ、これにより冷間圧延性を大幅に向上させるこ
とができる。According to the usual method for manufacturing At-killed steel sheets, the heating temperature of the steel billet is 12
After heating-soaking at a temperature above 00° C., the billet is extracted from the furnace. In contrast, according to the present invention, the steel billet is heated and maintained at a low temperature without performing the conventional treatment of decomposing At and N in the same bath, and the copper strip is wound after hot rolling. By setting the rolling temperature (℃T) to a high temperature according to the H/At ratio, it is possible to economically obtain hot-rolled steel strip with less solid solution N, thereby greatly improving cold rollability. can be done.

第１図は連続鋳造鋼片の加熱温度豐熱間圧延仕上温度（
ＦＴ　）および銅帯巻取り温度（（３Ｔ　）とΔｒとの
関係を示す図である。なおΔｒはカップに絞った後の耳
率とよく対応することから、Δｒを知ることによって耳
率を予測することができる。Figure 1 shows the heating temperature of continuously cast steel slabs and the finishing temperature of hot rolling (
FT) and copper strip winding temperature ((3T)) and Δr. Since Δr corresponds well to the selvage ratio after squeezing into a cup, the selvage ratio can be predicted by knowing Δr. can do.

第１図に示すように、鋼片の加熱温度による絞り加工性
の影響は少ないが、一方ＦＴおよびＯＴが絞り加工性に
及ぼす影響は大きいことが判る。As shown in FIG. 1, it can be seen that the heating temperature of the steel billet has little influence on the drawability, but on the other hand, FT and OT have a large influence on the drawability.

すなわちＦＴをγ領域またはα＋γ領域となすことによ
って結晶粒度が異なって材質の違いが太きくなり、かつ
熱延板の集合組織も異なるので、再結晶集合組織も異な
る。一方高温ＯＣＴで巻取ると自己焼鈍が進み結晶粒度
は大きくなり、炭化物組織の凝集粗大化及びＡｔＮ析出
率が最適値になるため材質ならびに集合組織も大きく変
化する。Δｒが小さくなる熱延温度としては、ＦＴにつ
いては高温のγ領域の温度であり、ＯＴについては、Ｆ
Ｔが高温あるいは低温のいずれの場合でも、高温の巻取
り温度である。従ってＦＴはＡｒ３変態点温度以上を確
保する必要があるっ 値があり、さらにＡｊ−の比に応じてＯＴの最適値が存
在することを見出した。That is, by forming the FT in the γ region or α+γ region, the crystal grain size differs and the material quality becomes thicker, and the texture of the hot rolled sheet also differs, so the recrystallization texture also differs. On the other hand, when the material is wound using high-temperature OCT, self-annealing progresses and the crystal grain size increases, the carbide structure becomes agglomerated and coarsened, and the AtN precipitation rate reaches its optimum value, resulting in a large change in material quality and texture. The hot rolling temperature at which Δr becomes small is the temperature in the high temperature γ region for FT, and the temperature in the high temperature γ region for OT.
Whether T is high or low, it is a high winding temperature. Therefore, it has been found that there is a value for FT that needs to be maintained above the Ar3 transformation point temperature, and that there is an optimum value for OT depending on the ratio of Aj-.

これらの関係かられかることは固溶Ｎｆｉｔ及びＡｔＮ
　ｆｉもΔｒに大きく影響していることがわがった。即
ち、ＡｔとＮｆｆ１は−の比が小さいとＡｔＮ　ｆ＋’
ｔが少なくなりすぎるし、「の比が大きいとＡ４Ｎ量が
多くなり過ぎて、結晶粒径や、集合組織に影響を及ぼす
。このＩｌ−の比に応じて最適ＣＴを選ぶことによりＡ
ｔＮ量を最適値に調整できて、Δｒに好結果を及ぼして
いると考えられろう 第３図はＦＴ　８５０℃、　（３Ｔ　６２０　ｔ；で施
された高温材についてΔｒにおよぼす冷間圧下率の影響
を示す図であり、同図より判るように冷間圧下率を８０
％から９５％の領域で大きく変化させた結果、前記冷間
圧下率が８５〜９３％の領域で冷間圧延した場合に、Δ
ｒが±０．２になることを本発明者らは新規に知見した
。What can be learned from these relationships is that solid solution Nfit and AtN
It was found that fi also greatly influenced Δr. That is, if the - ratio of At and Nff1 is small, AtN f+'
t becomes too small, and if the ratio is too large, the amount of A4N becomes too large, which affects the crystal grain size and texture.By selecting the optimum CT according to this ratio of Il-,
It is thought that the amount of tN can be adjusted to the optimum value, which has a good result on Δr. Figure 3 shows the cold rolling reduction rate on Δr for high-temperature material subjected to FT 850°C (3T 620 t). This is a diagram showing the influence, and as can be seen from the diagram, the cold reduction rate is 80
As a result of making a large change in the range from % to 95%, Δ
The present inventors have newly discovered that r is ±0.2.

第４図はＦＴ　８５０℃、　ＯＴ　６２０１：で施され
た高温材を冷間圧下率９０％で冷間圧延した材料につい
て、Δｒにおよぼす連続焼鈍の再結晶温度の影響を示す
図である。同図より判るように再結晶温度がＡ１変態点
温度（７２０℃）以下の場合には再結晶温度が高温にな
るに従ってΔｒは小さくなり、６５０〜７２０℃の領域
においてはΔｒが±０．２以下になることを本発明者ら
は新規に知見した。しかしながら７２０℃を越える温度
領域において連続焼鈍を施したものはΔｒか大きくなる
ことが判った。従って連続焼鈍の際の再結晶温度は６５
０〜７２０℃の範囲内にする必要がある。FIG. 4 is a diagram showing the influence of the recrystallization temperature of continuous annealing on Δr for a material obtained by cold rolling a high temperature material subjected to FT 850° C. and OT 6201: at a cold reduction ratio of 90%. As can be seen from the figure, when the recrystallization temperature is below the A1 transformation point temperature (720°C), Δr becomes smaller as the recrystallization temperature becomes higher, and in the region of 650 to 720°C, Δr is ±0.2 The present inventors have newly discovered the following. However, it was found that when continuous annealing was performed in a temperature range exceeding 720°C, Δr increased. Therefore, the recrystallization temperature during continuous annealing is 65
It is necessary to keep the temperature within the range of 0 to 720°C.

以上述べたように、本発明者らは絞り加工が施される薄
鋼板の製造方法において、耳が特に小さくなるすなわち
Δｒが±０．２以下になる薄鋼板の製造条件を連続鋳造
鋼片に適用する研究を重ねた結果、熱延温度・冷間圧下
率および連続焼鈍時の再結晶温度が重要な要因であり、
ＦＴをＡｒｓ温度以上となし、ＯＴを５８０℃以上の高
温にして巻き取った銅帯に冷間圧下率８５〜９３％で冷
間圧延を施した後、連続焼鈍時に６５０〜７２０℃の再
結晶焼鈍を施すことにより、Δｒの小さい絞り加工性に
優れた薄Ｍ板を製造することができることを新規に知見
したのである。As described above, the present inventors have developed a method for manufacturing thin steel sheets that undergoes drawing processing, and have set manufacturing conditions for thin steel sheets in which the selvedge is particularly small, that is, Δr is ±0.2 or less, to continuously cast steel billets. As a result of repeated research, the hot rolling temperature, cold reduction rate, and recrystallization temperature during continuous annealing are important factors.
After cold rolling at a cold reduction ratio of 85 to 93% to a copper strip wound with FT at Ars temperature or higher and OT at a high temperature of 580°C or higher, recrystallization at 650 to 720°C during continuous annealing. It was newly discovered that by annealing, it is possible to produce a thin M plate with a small Δr and excellent drawing workability.

次に本発明において成分組成を限定する理由を説明する
。Next, the reason for limiting the component composition in the present invention will be explained.

Ｃは、再結晶粒の成長を抑制する重要な元素であり、Ｃ
含有量を多くすると結晶粒径は小さくな９調質度の高い
ものが得られるが、Ｃが０．０９％より多いと硬度が高
くなり過ぎ冷間圧延性も悪くなる一方Ｃが０．０４％よ
り少ないとＡｒ５変態点温度が高くなって熱延鋼帯の全
幅ならびに全長にわたってγ領域で圧延を施すことが困
難になる。従ってＣは０．０４〜０．０９％の範囲内に
する必要がある。C is an important element that suppresses the growth of recrystallized grains, and C
If the content is increased, a product with a small crystal grain size and a high degree of tempering can be obtained, but if the C content is more than 0.09%, the hardness becomes too high and the cold rollability deteriorates, while the C content is 0.04%. If it is less than %, the Ar5 transformation point temperature becomes high and it becomes difficult to perform rolling in the γ region over the entire width and length of the hot rolled steel strip. Therefore, C needs to be within the range of 0.04 to 0.09%.

Ｓｌは、耐食性を劣化させ、さらに材質を極端に硬質化
させる元素であり、冷間圧延を妨げると共に調質度の制
御を困難にするので、製鋼時に特に添加する必要はなく
、むしろ耐火物中の５ｉｎ２が溶鋼中のＡｔで還元され
て鋼中に残留する程度にとどめなければならないことか
ら、Ｓｉは０．０２％以下にする必要がある。Sl is an element that deteriorates corrosion resistance and makes the material extremely hard. It obstructs cold rolling and makes it difficult to control the degree of tempering. Therefore, it is not necessary to specifically add it during steelmaking, but rather it is added to refractories. Since 5in2 of Si must be reduced by At in the molten steel and remain in the steel, the content of Si must be 0.02% or less.

Ｍｎは、熱延コイルの耳割れ発生を防ぐために有効な元
素であり、その添加量はＳ含有量に対応して定められ、
Ｓ含有量が少なければ過剰のＭｎを添加することは経済
的に好ましくないためＩｎの添加量は耳割れの発生が防
止される程度であればよいのでＫｎは０．４％以下にす
る必要がある。Mn is an effective element for preventing edge cracking in hot-rolled coils, and its addition amount is determined according to the S content.
If the S content is low, it is economically undesirable to add excessive Mn, so the amount of In added is sufficient as long as it prevents the occurrence of edge cracking, so Kn needs to be 0.4% or less. be.

Ｐは、材質を硬化させるばかりでなく、ブリキ等の耐食
性を劣化させるので、Ｐは０．０３％以下にする必要が
ある。P not only hardens the material, but also deteriorates the corrosion resistance of tinplate, etc., so P needs to be 0.03% or less.

Ｓは、その含有量に対応してＫｎが添加されることにな
り、Ｓが過剰に含有されると熱延コイルの耳割れならび
ＭｎＳ系介在物の存在による製缶時の割れ欠陥の原因と
なるので、Ｓは０．０２％以下にする必要がある。Kn is added in proportion to the S content, and excessive S content can cause edge cracks in hot-rolled coils and crack defects during can manufacturing due to the presence of MnS-based inclusions. Therefore, S needs to be 0.02% or less.

Ａｔは、ｖＡ＃Ｊ４時溶鋼の脱酸作用を果す元素であり
、鋼中にＡｔ含有量が多くなるに従って鋼の清浄度は高
くなるが、Ａｔが０．ｏｓｏ％より多いと鋼板に表面欠
陥を生起させ、さらに再結晶粒成長を抑制し、二方Ａｔ
が０．０１０％より少ないと再結晶粒径が太きくなり過
ぎてΔｒのばらつきが大きくなり、また深絞り加工後オ
レンジピールを呈するので、ＡＩは０．ｏｉｏ〜０．０
５０％の範囲内にする必要がある。At is an element that deoxidizes molten steel at vA#J4, and as the At content in the steel increases, the cleanliness of the steel increases, but when At is 0. If the amount exceeds oso%, surface defects will occur in the steel sheet, and recrystallized grain growth will be suppressed.
If it is less than 0.010%, the recrystallized grain size will become too thick and the variation in Δr will become large, and orange peel will appear after deep drawing, so the AI will be 0.010%. oio~0.0
It is necessary to keep it within 50%.

Ｎは、０．０１％より多くＮを含有する綱は材質が硬質
化するので、Ｎは０．０１％以下にする必要がある。Since a steel containing more than 0.01% of N becomes hard, the N content must be 0.01% or less.

Ｎ／ＡｔはＡｔＮを析出させ、固溶Ｎ（付を最適値にす
るために、０．０５　〈７　＜　０．３に調整する必要
かある。N/At may need to be adjusted to 0.05 <7 < 0.3 in order to precipitate AtN and obtain the optimum value for solid solution N.

ところで、上記成分組成範囲の鋼は、各種転炉→真空脱
ガス処理（但しこの処理は省略される場合もある。）→
連続鋳造の一連の工程を経て製造される。By the way, steel with the above composition range is processed through various converter furnaces → vacuum degassing treatment (however, this treatment may be omitted in some cases) →
Manufactured through a series of continuous casting processes.

次に本発明において製造条件を限定する理由を説明する
。Next, the reason for limiting the manufacturing conditions in the present invention will be explained.

熱間圧延の際鋼片を加熱炉から抽出する加熱炉抽出温度
が１２００℃を超えると、ＡｔとＮは分解して鋼中に固
溶する量が多くなり、一方１１００℃より低いと圧延性
が悪くなるので、加熱炉抽出温度は１１００〜１２００
℃の範囲内にする必要がある。このようにすることによ
り、Ａｔキルド鋼特有の冷間圧延性不良（スリップ現象
および／まだはチャタリング現象）も解決される。When the heating furnace extraction temperature at which the steel billet is extracted from the heating furnace during hot rolling exceeds 1,200°C, At and N decompose and become solid solution in the steel in large amounts, whereas when it is lower than 1,100°C, the rolling properties deteriorate. The heating furnace extraction temperature should be set at 1100 to 1200.
Must be within the range of °C. By doing so, the poor cold rollability (slip phenomenon and/or chattering phenomenon) peculiar to At-killed steel can be solved.

熱延仕上温度ＦＴはＡｒｓ変態点温度より低いと耳率が
大きくなるので、熱延仕上温度ＦＴはＡｒ３変態点温度
以上にする必要がある。If the hot rolling finishing temperature FT is lower than the Ars transformation point temperature, the selvage will increase, so the hot rolling finishing temperature FT needs to be equal to or higher than the Ar3 transformation point temperature.

巻取り温度ＯＴは、先に第１図を参照して説明したよう
に、高温にすればΔｒは小さくなるが、熱延鋼帯を巻取
って自己焼鈍を行なう際コイルの外周部の冷却速度が内
部に比べて大きくなり、内部は結晶粒径が大きくなって
も外部は若干小さくなし、結果的に熱延鋼帯内で不均一
な組織となる。As explained earlier with reference to Fig. 1, when the winding temperature OT is set to a high temperature, Δr becomes smaller, but when the hot rolled steel strip is wound and self-annealed, the cooling rate of the outer circumference of the coil is becomes larger than the inside, and even though the grain size becomes large inside, the outside becomes slightly smaller, resulting in a non-uniform structure within the hot-rolled steel strip.

この現象は巻取り温度ＧＴが高温になるに従って大きく
なり、特に７００℃より高いと大きくなる。This phenomenon increases as the winding temperature GT increases, and particularly increases when the winding temperature GT becomes higher than 700°C.

一方ＣＴが５４０℃よ抄低いとΔｒが大となるので巻取
り温度は、Δｒが±０．２以下になりかつ組織の不均質
化が大きくない、５８０〜６８０℃の温度範囲内にする
必要がある。On the other hand, if CT is lower than 540°C, Δr becomes large, so the winding temperature must be within the temperature range of 580 to 680°C, so that Δr is ±0.2 or less and the structure is not significantly heterogeneous. There is.

又、ＣＴを高温にすると銅帯表面のスケール層が厚くな
り、次工程の酸洗工程における脱スケール性が悪くなる
ので、いずれの条件においても低温が好ましい。従って
、Ｎ／Ａｔの比に応じてΔｒの小さくなるＣＴを選んで
巻き取ることが重要である。Furthermore, if CT is heated to a high temperature, the scale layer on the surface of the copper strip will become thicker, and the descaling performance in the next pickling process will be impaired, so a low temperature is preferable under all conditions. Therefore, it is important to select and wind a CT with a small Δr according to the ratio of N/At.

一方、低温側は前述のとおり結晶粒径が小さくｋること
、及びＡｔＨの析出率が小さくなるので、これらを満足
できることを条件に選んだ。On the other hand, on the low temperature side, as mentioned above, the crystal grain size is small and the precipitation rate of AtH is small, so it was selected on the condition that these conditions could be satisfied.

従って、巻取や　は　３００π＋６１０より低温で３０
０　ｉ＋　５２０より高温の範囲で行う。Therefore, the winding temperature is 30 at a temperature lower than 300π+610.
It is carried out at a temperature higher than 0 i+ 520.

巻取られた鋼帯は、酸洗後冷間圧延される。この際の圧
下率は８５％より小さくても、また９３％より大きくて
もΔｒが大きくなるので、冷間圧延の圧下率は８５〜９
３％の範囲内にする必要がある。The wound steel strip is pickled and then cold rolled. Even if the rolling reduction at this time is smaller than 85% or larger than 93%, Δr becomes large, so the rolling reduction in cold rolling is 85 to 9.
It is necessary to keep it within 3%.

上記冷間圧延後連続焼鈍によす６５０〜７２０℃の温度
範囲内で再結晶焼鈍が施される。このような再結晶焼鈍
を施す理由は、結晶粒径を大きくするとΔｒは小さくな
ることは知られており、本発明によればより均一な鋼帯
を得るためにＣとＡｔの含有量の下限をそれぞれ０．０
４％、　０．ｏｔｏ％に規制していることがら冷間圧延
後の結晶粒径は小さくなる傾向にあるので、結晶粒の成
長を促すため比較的高温で再結晶焼鈍が施される。その
際上記焼鈍温度が６５０℃より低いと結晶粒が十分に粗
大化しないため結晶粒径が小さくてΔｒが大きくなり、
一方７２０℃より局いとＡ１変態点温度を超えてΔｒの
ばらつきが大きくなることを本発明者らは新規に知見し
たので、連続焼鈍による再結晶焼鈍温度を６８０〜７２
０℃の範囲内にしたのである。Recrystallization annealing is performed within the temperature range of 650 to 720°C, which is the same as the continuous annealing after the cold rolling. The reason for performing such recrystallization annealing is that it is known that Δr decreases as the grain size increases, and according to the present invention, in order to obtain a more uniform steel strip, the lower limit of the content of C and At is 0.0 each
4%, 0. Since the crystal grain size after cold rolling tends to become smaller since it is restricted to oto%, recrystallization annealing is performed at a relatively high temperature to promote crystal grain growth. At that time, if the annealing temperature is lower than 650°C, the crystal grains will not become coarse enough, resulting in a small crystal grain size and a large Δr.
On the other hand, the present inventors have newly found that the variation in Δr becomes large when the temperature exceeds the A1 transformation temperature when the temperature is higher than 720°C.
The temperature was kept within the range of 0°C.

再結晶焼鈍後の調質圧延は、調質度、平坦度を得ると共
に板面粗度を決めるために施され、その圧下率は通常の
調質圧延のそれと同じ＜０．５〜２．０％の範囲内にす
る。The skin pass rolling after recrystallization annealing is performed to obtain the temper degree and flatness as well as determine the plate surface roughness, and the rolling reduction is <0.5 to 2.0, which is the same as that of normal skin pass rolling. within the range of %.

次に本発明を実施例について説明する。Next, the present invention will be explained with reference to examples.

実施例 下記表に示す成分組成を有する鋼を転炉により溶製し、
その後真空脱ガス処理を施し、連続鋳造して清浄度の優
れた鋼片を得た。この鋼片を熱間圧延して１．８鴎、２
．０園、２．５鴎、３．３闘厚の熱延コイルとした。こ
の際の鋼片の加熱炉抽出温度。Example Steel having the composition shown in the table below was melted in a converter,
After that, it was subjected to vacuum degassing treatment and continuously cast to obtain a steel billet with excellent cleanliness. This steel piece was hot-rolled to yield 1.8 mm and 2 mm.
．． The hot-rolled coil had a thickness of 0, 2.5, and 3.3. The heating furnace extraction temperature of the steel billet at this time.

圧延仕上温度（ＦＴ　）および圧延鋼帯巻取り温度（℃
Ｔ）は表に示すようであった。これら熱延コイルを酸洗
して脱スケールした。次に６スタンドタンデム４圧延機
を用いて冷間圧延して０．２１１１１１゜０．３１１１
１１厚の冷延鋼板を得た。続いて連続焼鈍法により単純
ヒートサイクルにより再結晶焼鈍を施した後調質圧延を
行なった。Rolling finishing temperature (FT) and rolled steel strip winding temperature (℃
T) was as shown in the table. These hot rolled coils were descaled by pickling. Next, it was cold rolled using a 6-stand tandem 4 rolling mill to 0.211111°0.3111
A cold rolled steel plate having a thickness of 11 was obtained. Subsequently, recrystallization annealing was performed using a simple heat cycle using a continuous annealing method, followed by temper rolling.

このようにして得た冷延鋼板をブリキおよびＴＦＳに仕
上げ、　ＤＲＤ製缶を行い、耳率（ΔＨ）の測定および
缶壁の肌荒れ（オレンジピール）判定に基いて綜合判定
の結果を表に示す。なおΔＨの測定は第５図に示すよう
にして行なった。The cold-rolled steel sheets obtained in this way were finished into tin plate and TFS, and DRD can manufacturing was performed. The table shows the results of the overall evaluation based on the measurement of the selvedge ratio (ΔH) and the roughness (orange peel) evaluation of the can wall. . Note that the measurement of ΔH was carried out as shown in FIG.

（発明の効果） 上記実施例より判るように、本発明により得られた薄鋼
板を使用してブリキ・ＴＦＳにそれぞれ仕上げてＤＲＤ
製缶を行なうと、耳率の小さい、肌荒れのない品質の良
い缶を製造することが″できた。(Effects of the invention) As can be seen from the above examples, the thin steel sheets obtained by the present invention are used to finish tin plate and TFS, respectively, and perform DRD.
During can manufacturing, it was possible to produce high-quality cans with a small selvage rate and no rough skin.

この他に先に特開昭５８−１５１４２６号により本発明
者らが提案した方法によれば冷間圧延を２回施す必要が
あるのに比べ、本発明によれば１回の冷間圧延を施すだ
けでよいことから、製造コストをも低減させることがで
きる。さらにまた本発明により得られる鋼板は全幅なら
びに全長が均質であるため、ＤＲＤ製缶機によりこの鋼
板を製缶すると、高速で良質缶を得ることができるので
、従来方法により得られた鋼板を用いて製缶する場合に
比し７計画通りの生産を確実に達成することができる。In addition, according to the method previously proposed by the present inventors in JP-A-58-151426, it is necessary to perform cold rolling twice, but according to the present invention, cold rolling is performed once. Since it is only necessary to apply it, manufacturing costs can also be reduced. Furthermore, since the steel plate obtained by the present invention is uniform in overall width and length, if this steel plate is made using a DRD can making machine, a high quality can can be obtained at high speed. Compared to the case where cans are manufactured using the same method, production according to the plan can be achieved more reliably.

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

第１図はΔｒに及ぼす鋼片加熱炉抽出温度・ＦＴおよび
ＣＴの影響を示す図、第２図はΔｒに及ぼす冷間圧延圧
下率の影響を示す図、第３図はΔｒに及ぼす連続焼鈍再
結晶温度の影響を示すロ、第４図は本発明のために行な
った実験室規模のＤＲＤ製缶の斜視説明図である。Figure 1 is a diagram showing the influence of billet heating furnace extraction temperature, FT and CT on Δr, Figure 2 is a diagram showing the influence of cold rolling reduction on Δr, and Figure 3 is a diagram showing the influence of continuous annealing on Δr. FIG. 4, which shows the effect of recrystallization temperature, is a perspective explanatory view of laboratory-scale DRD can manufacturing carried out for the purpose of the present invention.

Claims (1)

【特許請求の範囲】[Claims] １、Ｃ０．０４〜０．０９％、Ｓｉ０．０２％以下、Ｍ
ｎ０．４％以下、Ｐ０．０３％以下、Ｓ０．０２％以下
、Ａｌ０．０１０〜０．０５０％、Ｎ０．０１％以下そ
して０．０５＜Ｎ／Ａｌ＜０．３、残部Ｆｅおよび不可
避的不純物よりなる連続鋳造鋼片に熱間圧延を施す際の
鋼片の加熱炉よりの抽出温度を１１００〜１２００℃に
、熱間圧延仕上温度をＡｒ＿３変態点温度以上に、巻取
り温度を３００（Ｎ／Ａｌ）＋６１０（℃）より低温で
、３００（Ｎ／Ａｌ）＋５２０（℃）より高温の範囲で
行つて熱延鋼帯となし、次に酸洗後圧下率８５〜９３％
で冷間圧延を、連続焼鈍法によりＡ＿１変態点温度の直
下である７２０〜６５０℃の温度で再結晶焼鈍を、さら
に圧下率０．５〜２．０％で調質圧延を順次施すことを
特徴とする硬質かつ絞り加工性に優れる面内異方性の小
さい缶用薄鋼板の製造方法。1, C0.04-0.09%, Si0.02% or less, M
n0.4% or less, P0.03% or less, S0.02% or less, Al0.010-0.050%, N0.01% or less and 0.05<N/Al<0.3, balance Fe and unavoidable When hot rolling a continuously cast steel billet containing impurities, the extraction temperature of the steel billet from the heating furnace is set at 1100-1200°C, the hot rolling finishing temperature is set at Ar_3 transformation point temperature or higher, and the coiling temperature is set at 300°C ( N/Al)+610(℃) and higher temperature than 300(N/Al)+520(℃) to form a hot rolled steel strip, then pickling and rolling reduction of 85 to 93%.
cold rolling, recrystallization annealing at a temperature of 720 to 650 °C, which is just below the A_1 transformation point temperature, by continuous annealing method, and skin pass rolling at a reduction rate of 0.5 to 2.0%. A method for manufacturing a thin steel sheet for cans that is characterized by being hard, has excellent drawing workability, and has small in-plane anisotropy.