JPS6214202B2 - - Google Patents
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- Publication number
- JPS6214202B2 JPS6214202B2 JP57022771A JP2277182A JPS6214202B2 JP S6214202 B2 JPS6214202 B2 JP S6214202B2 JP 57022771 A JP57022771 A JP 57022771A JP 2277182 A JP2277182 A JP 2277182A JP S6214202 B2 JPS6214202 B2 JP S6214202B2
- Authority
- JP
- Japan
- Prior art keywords
- less
- ultra
- rolled
- temperature
- rolled steel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000010960 cold rolled steel Substances 0.000 claims description 29
- 238000004519 manufacturing process Methods 0.000 claims description 25
- 238000000137 annealing Methods 0.000 claims description 7
- 238000005096 rolling process Methods 0.000 claims description 7
- 230000009466 transformation Effects 0.000 claims description 5
- 238000001953 recrystallisation Methods 0.000 claims description 4
- 229910000655 Killed steel Inorganic materials 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 238000005097 cold rolling Methods 0.000 claims description 3
- 238000005554 pickling Methods 0.000 claims description 3
- 229910052717 sulfur Inorganic materials 0.000 claims description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 238000000034 method Methods 0.000 description 28
- 229910000831 Steel Inorganic materials 0.000 description 25
- 239000010959 steel Substances 0.000 description 25
- 230000007547 defect Effects 0.000 description 24
- 235000019592 roughness Nutrition 0.000 description 17
- 238000010409 ironing Methods 0.000 description 14
- 239000013078 crystal Substances 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 238000005336 cracking Methods 0.000 description 8
- 230000003746 surface roughness Effects 0.000 description 8
- 238000004804 winding Methods 0.000 description 6
- 230000002950 deficient Effects 0.000 description 5
- 235000019589 hardness Nutrition 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 4
- 235000013305 food Nutrition 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000009849 vacuum degassing Methods 0.000 description 4
- 235000014171 carbonated beverage Nutrition 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000005028 tinplate Substances 0.000 description 3
- 235000013405 beer Nutrition 0.000 description 2
- 235000013361 beverage Nutrition 0.000 description 2
- 230000003749 cleanliness Effects 0.000 description 2
- 238000009749 continuous casting Methods 0.000 description 2
- 230000008094 contradictory effect Effects 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910001374 Invar Inorganic materials 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 208000009205 Tinnitus Diseases 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005219 brazing Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 235000000396 iron Nutrition 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 235000015192 vegetable juice Nutrition 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Heat Treatment Of Sheet Steel (AREA)
Description
この発明は、製缶加工性、なかでも飲料缶など
に使われる缶として、絞り加工（Drawing）と、
しごき加工（Ironning）とを複合した製缶法（以
下DI法という）適用による製缶加工性に優れる
極薄鋼板の製造方法に関するものである。
ビールや炭酸飲料などを充てんする缶（以下食
缶という）は古くは、胴部、天部及び底部すなわ
ち地部よりなる３点の部品で組み立てる、いわゆ
る３ピース缶が使われて来たがこれは胴板をロー
ル成形、あるいはインバー成形によつて円筒状に
加工した後、はんだによるろう接着や、ナイロン
樹脂などによる化学接着あるいは溶接により接合
した円筒に、天板を巻き締め法で接合した後、食
品や飲料を充てんし、最後に地板を巻き締め法で
接合して完成される。
しかし、製缶能率、製缶コストさらには缶機能
の優位性から近年製缶法も大きく進歩し、胴部と
地部を絞り加工としごき加工で一体成形できる
DI製缶法が広く採用されるに至つている。
このDI製缶法でつくられる食缶は胴部と地部
が一体で、天部を組み立てるだけなので２ピース
缶とも言われている。
DI製缶法には、ぶりきまたは、特殊処理を施
しプレス加工性に優れる低炭素極薄冷延鋼板のコ
イルが使われ、そのコイルから円板を打ち抜くと
同時に絞り加工をあわせ施してカツプ状に連続し
て成形される。
次に、このカツプはボデイーメーカーに運ば
れ、缶仕様によつては、例えば缶高さの高いもの
では再度絞り加工が加えられこゝに連続して数段
に分割されたしごき加工が行なわれて製缶され、
もちろん缶高さの低いものは再絞り加工が省略さ
れる場合もある。
この再絞り加工は50〜150ストローク／分とい
う高能率で連続して行なわれるのが通例なので、
ボデイーメーカー内でトラブルが生じると大量の
不良が発生するだけでなく、とくに精密に構成さ
れているマシンを解体し不良缶を除去する作業も
必要になり、製缶能率が大幅に低下する。
元来かようなDI製缶法は、胴部板厚が、しご
き加工により原板厚と比べて極端に薄くなる過酷
な製缶であり、例えば0.3mmの極薄冷延鋼板を使
つて胴部板厚が0.09〜0.16mmまでしごき加工が行
なわれる。
加えてこのしごき加工後に、天部を接合するた
めのフランジ出し加工が行なわれ、この加工は前
述のようなしごき加工が行なわれた後だけに、鋼
中の介在物や表面欠陥等が加工割れになる感受性
が高く、それ故清浄度の高いことはもちろん、よ
り均一なパターンを有する表面あらさ、さらには
加工割れにつながる表面欠陥の少ない極薄冷延鋼
板を用いることが必要とされている。
以上の要請を満たすため、DI製缶法に供され
る極薄冷延鋼板としては、素材に連鋳Alキルド
鋼スラブを使い、そして通常の工程を経て結晶粒
が等軸晶のものがよいとされていた。例えば、特
公昭55−2461号公報（製缶用薄鋼板）でも述べて
いるように、結晶粒軸比が1.8以下に小さくした
ものは、しごき成形不良率と、フランジ成形不良
率を大幅に減じることができると言われている。
しかるにDI法による製缶時に発生する不良に
ついて発明者らがさらにいろいろ調べ、その原因
を分析して発生起因別に分類した結果によると、
極薄冷延鋼板に大きく起因する欠陥としては抜け
不良とフランジ割れがとくに重要であることを知
つた。
進んでこれらの欠陥が極薄冷延鋼板の何に起因
するかを詳細に調べたところ、抜け不良もフラン
ジ割れについても、結晶粒軸比にはあまり関係が
なく、抜け不良は結晶粒径が小さくなるに従つて
多発すること、さらに、板面のあらさとも関係が
あり、あらさの小さいものでは多発する傾向があ
ることが突きとめられるに至つた。
しかし、フランジ割れも結晶粒度との関係があ
り、とくにこの場合は抜け不良とは逆で、結晶粒
度が小さくなるほどその不良率は高くなることが
わかつた。
発明者らは、この相矛盾する関係において、抜
け不良発生率が少なく、フランジ割れ不良率も少
ない、DI製缶法に適した極薄冷延鋼板をつくる
ことに成功した。
ここで抜け不良とは、しごき加工工程でポンチ
とダイにより事前に成形されたカツプを、しごい
て缶体をつくる場合に、しごき加工が終つてから
缶体をポンチから抜きとるとき、完全に抜け切ら
ないものができることを言い、この場合、このト
ラブルの発見が遅れると、次々と高能率でカツプ
が送られてくるのでカツプが詰まつてしまい、そ
の損失は大きい。
こゝに絞り加工を経たカツプのポンチの周囲に
おける再絞り加工による缶体を、ポンチから離脱
するのに必要な力をストリツプ力と言うことにし
て、ストリツプ力が大きくなるような極薄冷延鋼
板を使つた場合、抜け不良が多発し、また抜け性
が悪いものについて強引に抜こうとしてストリツ
プ力を大きくした場合には、缶体は抜けても、缶
体に疵が入り、このような缶を発見して除去する
ことが高能率操業の下で一般に難づかしいため、
次工程にそのまゝ流れることが多い。そうすると
後工程の印刷では、印刷に使われるブランケツト
表面に疵が入り、印刷模様に乱れが生じるトラブ
ルが続発する。
従つて、ボデイーメーカーからは、より小さな
ストリツプ力で、従つて缶に疵をつけることなく
抜くことができることが強く要求される。
より小さなストリツプ力で缶体が容易に抜ける
ようにするためには、しごき加工後の缶体内面と
ポンチ面との摩擦係数を小さくすることができれ
ばよく、摩擦係数を小さくするにはプレス加工油
を潤滑油として缶体とポンチ間に多く残留、付着
させて潤滑性を向上することによつて可能であ
る。従つて極薄冷延鋼板としては、しごき加工後
の缶体内面のあらさを大きくすることができれば
良いと考えられた。
とは云うもののしごき加工後のあらさが大きく
なるような極薄冷延鋼板をつくることは、それが
酷な加工を受けた後のことなので実際的な立場で
は甚しい難問であつたのである。
以上の点について、発明者らは鋭意研究を重ね
た結果、以下のべるようにして、これらの問題を
有利に解決し、DI法による製缶加工性に優れる
極薄冷延鋼板をこゝに提案するものである。
まず第１図に抜け不良に及ぼす結晶粒度（Ｇ、
Ｓ、No）と極薄冷延鋼板の中心線あらさRa（μ
ｍ）の影響について示すが、こゝに抜け不良は
GSNo.がほゞ10.0〜11.0においてより大きくなる
と、即ち粒径が小さくなるに従つて、いずれのも
のでも悪くなる明瞭な関係が見い出され、同時
に、中心線あらさ2.5μｍRa〜1.0μｍRaにおい
て値がより小さくなるに従つて、いずれのGSNo.
においても抜け不良率が高くなる傾向が見られ
る。
次に第２図には、極薄冷延鋼板のRaとGSNo.と
が種々に異なつたぶりきを用いてしごき加工を行
つた後、ポンチから抜いた缶体内面における中心
線あらさが抜け不良に及ぼす関係を整理して図示
したが、極薄冷延鋼板のあらさが大きいほど、ま
たGSNo.が小さいものほど、しごき加工後の缶体
内面における中心線あらさが大きくなり、それに
従つて抜け不良も少ないという結果が得られた。
さらに第３図には極薄冷延鋼板のGSNo.としご
き加工後フランジ出し加工を行つた際の割れ不良
率との関係を示すが、GSNo.が9.2以下に粒径の大
きいものではフランジ割れが多発する傾向が見い
出せた。
以上の結果から、DI製缶時に発生する不良の
うち冷延鋼板に起因する欠陥である抜け不良とフ
ランジ割れを少なくできる極薄冷延鋼板として
は、次の条件が必要であることがわかつた。
上に大きくし、しかし、あまり大きいと結晶粒
が細くなりすぎ加工性が悪くなるのでGSNo.11.0
を上限とする。また抜け不良を防ぐためには、極
薄冷延鋼板のGSNo.およびRaを組み合せて調整す
ることすなわち両者の差（GSNo.―Ra）9.0の関
係を満たすことによつて達成できることを知見し
た。
もちろん現実に極薄冷延鋼板のあらさは、缶の
外観の見栄えや好みなどで決定されるので、まず
Raが決まつて、次にGSNo.を合せることになる。
以上の究明事実に立脚してこの出願は、次の事
項を不可欠とする。この発明は重量でＣ；0.01〜
0.08％を含み、Si；0.06％以下、Ｐ；0.03％以
下、Ｓ；0.03％以下、Al；0.08％以下、Ｎ；
0.015％以下であつて、Mnを0.5％以内、Mn／Ｓ
≧10となる量において含有し、残部実質的にFe
の組成からなる低炭素Alキルド鋼を、仕上温度
Ar3変態点以上、900℃以下で熱間圧延し、巻取
り温度450℃〜680℃で巻取り、続いて酸洗後冷間
圧延を行ない、次で結晶粒度がGSNo.で9.2〜11.0
になるよう再結晶温度以上680℃以下の温度で箱
焼鈍し、続いて前記GSNo.と板面の中心線平均あ
らさをあらわすRa（μｍ）との差が9.0以下にな
るように調質圧延を施すことを特徴とする製缶加
工性に優れる極薄冷延鋼板の製造方法である。
この発明において極薄冷延鋼板の成分組成を限
定する理由を次に説明する。
Ｃは再結晶粒の成長を抑制する重要な成分であ
り、Ｃ量を多くすると結晶粒径は小さくなつて硬
質化するとともに、抜け性も悪くなつてDI製缶
性を妨げるのでその上限を0.08％に規制し、一方
Ｃ量を少なくするとGSNo.が小さくなるので、抜
け性は改善されるものの、フランジ割れは増加
し、さらにぶりきとしたとき軟質となつて食缶の
内圧に対し強さが十分には耐え難くなるおそれが
あるので、Ｃ量の下限をかような心配のない0.01
％とした。
Siはぶりきの耐食性を劣化させる有害成分であ
るし、さらに材質を極端に硬質化してDI法によ
る製缶性を妨げ、それ故過剰な含有は避けるべき
であり、製鋼時に敢えて添加する必要はなく、耐
火物中のSiO2が溶鋼中のAlで還元されて残留す
る程度すなわち0.06％以下ならば許容される不可
避混入不純物といえる。
Ｐも材質を硬質化するとともに、ぶりきの耐食
性を劣化させる成分なので過剰な含有は好ましく
なく、製鋼時に経済的に脱隣できる程度の0.03％
以下で許容される不純物である。
ＳはMn量との関係において過剰に含有すると
熱延コイルの耳割れやMnS系介在物となつてフ
ランジ割れ起因になるものもあるので多量の含有
は好ましくないが製鋼時に経済的に脱硫できる程
度の0.03％以下で許容され得る混入不純物であ
る。
Alは鋼の精錬過程において、脱酸剤の役目を
果すことでは重要な成分であつて鋼中のAl量は
その含有量が多くなるに従つて鋼の清浄度は高く
なるが、過剰の添加は経済的に好ましくないばか
りでなく、結晶粒の成長を抑制する不利があり、
従つて、0.08％以下にしなければならず、一方で
基本的には溶鋼中の固溶酸素量に見合つた量にお
いて脱酸を完了できれば、金属Alとしては必ず
しも鋼中に残留させる必要はないとも云える反面
でAl量が少ないと結晶粒径が大きくなつて、フ
ランジ割れがやや増加するとともに、材質が軟質
になるきらいがあり、こゝにAlの下限量は0.003
％がのぞましい。尚、製鋼段階でAl添加量が少
ないと鋼の清浄度が悪くなる傾向にあるので、別
途溶鋼から介在物の浮上分離を促進させるため、
真空脱ガス処理などによる溶鋼の強撹拌を行うこ
とが必要となるが、その工程附加は近年ほぼ工程
化されている。
ＮはAlNの析出や固溶Ｎの残留によつて、結晶
粒の成長を抑制したり、材質を硬質化する。従つ
て、Ｎ量については0.015％以下さらにのぞまし
くは0.0025％程度に低減することがのぞましい。
一方、Ｎは鋼片の製造過程において空気からの混
入で約0.008％程度含有されることとなる。従つ
て、必要に応じて窒化Mn等の添加で容易に制御
することができる。
Mnは熱延コイルの耳割れ発生を防ぐために添
加する必要があるが、それはＳ量によつて支配さ
れる。耳割れを防ぐために必要なMn量は経験的
にMn／Ｓ10を確保することで可能である。従
つてMn量はＳ量との関係で決まるが、上限は敢
えて多く添加する必要がないので0.5％、下限は
Mn／Ｓ10によつて定まる。
次にGSNo.9.2〜11.0を確保するため、次の条件
が与えられる。
先ず、前述の成分範囲の鋼は、各種転炉→真空
脱ガス処理→連続鋳造、あるいはこの工程におい
て真空脱ガス処理を省いても容易につくることが
でき、この連続鋳造鋼片を使つて熱間圧延を行う
がその際、
仕上温度はAr3変態点温度以上900℃以下、巻
取温度は450℃以上680℃以下にする。ここで仕上
温度をAr3変態点以上としたのは、Ar3変態点未
満となると結晶粒径が大きくなり肌荒れを起す原
因となるのでAr3変態点以上とする。また900℃
を超えると脱スケール性が悪くなりスケールによ
る表面欠陥が多くなること及び加熱炉のエネルギ
ー原単位が高くなり経済的でないからである。
一方巻取り温度は450℃より低くなると鋼帯に
冷却むらが生じ均一な品質が得られないこと及び
結晶粒径が細くなりすぎ箱焼鈍を行なつても所定
のGSNo.が得られなくなり、また、巻取温度が680
℃を超えると結晶粒径が大きくなりすぎること及
び脱スケール性が悪くなり表面欠陥が発生しやす
くなることが限定の理由である。このようにして
得られた鋼帯を、酸洗を行ない、所望の製品板厚
に冷間圧延してから、再結晶温度以上680℃以下
の範囲から、成分組成、仕上温度、及び巻取り温
度に応じて結晶粒度がGSNo.で9.2〜11.0となるよ
うに選択した温度で箱焼鈍を行ない、再結晶及び
粒度成長を図り所定の結晶粒径を得る。
なおこの場合箱焼鈍温度は例えば巻取り温度が
450〜680℃のうち低目のときは比較的高く逆に巻
取温度が高目のときには、比較的低くすることに
よつて容易に所定の結晶粒径が得られる。
なお箱焼鈍温度680℃以下としたのは、これよ
り高温となると結晶粒径が粗大化し、所定の結晶
粒径が得られないためである。
以上の工程条件を管理することによつてG.S.No.
9.2〜11.0は容易に得られる。
さらに、単にGSNo.のみを調整しても抜け不良
を軽減することはできず、種々検討した結果抜け
不良を防ぐにはGSNo.および表面あらさRa（μ
ｍ）を組み合わせて調整することすなわち両者の
差（GSNo.―Ra）9.0の関係を満たすことによつ
て達成できることを見い出した。
ここに表面あらさRaはJISB0601による中心線
平均あらさを意味し、カツトオフ値0.8mm、測定
長さ2.5mmでの値である。
第４図にGSNo.―Raと抜け不良率との関係を示
す。第４図から明らかなようにGSNo.―Raを9.0以
下とすることにより、大幅に抜け不良率を低下さ
せることができる。
次に極薄冷延鋼板の表面あらさは、調質圧延機
のワークロール粗度によつて決まり、それはロー
ル粗度Ｘ転写率で求まる。
従つて、必要とするあらさの鋼板を得るために
は、それに適した粗度を有するロールを使うこと
によつて、容易に得られる。
もちろん現実には極薄冷延鋼板のあらさは、缶
の外観や見栄えや好みによつて決定されるので、
まずRaが決まつて、次にGSNo.を合わせることに
なる。一方GSNo.は、上記した成分組成、仕上げ
温度、巻取り温度および箱焼鈍温度を管理するこ
とによつて所定のGSNo.を得ることができる。
次に極薄冷延鋼板の硬さは、DI法による製缶
素材としてロツクウエルフイツシヤ硬さ試験の
30Tスケールでの値（HR30Tであらわす）で46
〜60の範囲で適合する。こゝで缶用素材に必要な
材質は、缶体内に内容物を充てんした、いわゆる
缶詰の状態で決まる。すなわち、缶詰となつた缶
体に必要な強度は缶の内圧強度で決められ、そし
てそろ内圧強度は充てん物によつてかわる。例え
ば、ビールや炭酸飲料など充てん物からガスが発
生して、缶の内圧を高めるもの、また、野菜ジユ
ースのようにガスの出ないものなどによつて異な
つてくる。従つてDI缶用素材としても硬さの異
なるものが必要になり、そのために、上記の
HR46〜60というのはT1（HR30T：46〜52）、T2
（50〜56）、T2１／２（52〜58）、T3（54〜60）の区分
範囲を通した全範囲を意味し、各区分硬度範囲は
冷延鋼板の使途に応じて上述の製造条件を勧案す
ること、冷延鋼板の調質圧延および、ぶりきを行
う際に考慮することによつて達せられる。
表１に示す鋼板成分において原料鋼を転炉で溶
製、Ｃ量が0.01％の供試番号１〜３については、
真空脱ガス処理を行い、その余の試料はそのまゝ
何れも連続鋳造機にて鋼片をつくり、これらを熱
間圧延機にて同表の条件で2.6mmの熱延コイルと
した後、酸洗、脱スケールを経て、次に６スタン
ドタンデム冷間圧延機にて0.3mmの極薄板厚に圧
延した後、同表に掲げた条件で箱焼鈍した。
続いて調質圧延機にて、圧下率1.5±0.5％、そ
して各種の板面あらさが得られるようにロール粗
度の異なるワークロールを使つて調質圧延を施し
た。
This invention improves can manufacturing processability, especially drawing processing for cans used for beverage cans, etc.
The present invention relates to a method for producing ultra-thin steel sheets with excellent can-making processability by applying a can-making method (hereinafter referred to as the DI method) that combines ironing. In the past, cans for filling beer, carbonated drinks, etc. (hereinafter referred to as food cans) were assembled from three parts: a body, a top, and a bottom, or so-called three-piece cans. After the body plate is processed into a cylindrical shape by roll forming or invar forming, the top plate is joined to the cylinder by brazing with solder, chemical bonding with nylon resin, or welding, and then the top plate is joined by the tightening method. It is then filled with food and beverages, and finally the main plate is joined using the rolling method. However, due to the superiority of can manufacturing efficiency, can manufacturing cost, and can function, can manufacturing methods have made great strides in recent years, and the body and base can be integrally formed by drawing and ironing.
The DI can manufacturing method has come to be widely adopted. Food cans made using this DI can manufacturing method are also called two-piece cans because the body and base are integrated, and only the top is assembled. The DI can making method uses tinplate or a coil of low-carbon, ultra-thin cold-rolled steel sheet that has undergone special treatment and has excellent press workability.A disk is punched out from the coil, and at the same time, a drawing process is also applied to form a cup shape. It is continuously molded. Next, this cup is transported to a body maker, and depending on the can specifications, for example, if the can is tall, it is drawn again and then ironed in several successive stages. canned by
Of course, for cans with a low height, re-drawing may be omitted. This re-drawing process is usually performed continuously at a high efficiency of 50 to 150 strokes/minute.
If a problem occurs within the body maker, not only will a large number of defects occur, but it will also be necessary to disassemble the precisely constructed machine and remove the defective cans, which will significantly reduce can manufacturing efficiency. Originally, the DI can manufacturing method was a harsh can manufacturing process in which the thickness of the body plate was extremely thin compared to the original plate thickness due to ironing. Ironing is performed until the plate thickness is 0.09 to 0.16 mm. In addition, after this ironing process, a flange process is performed to join the top part, and this process is performed only after the ironing process described above, so that inclusions and surface defects in the steel can cause processing cracks. Therefore, it is necessary to use ultra-thin cold-rolled steel sheets that not only have high cleanliness but also have surface roughness with a more uniform pattern and fewer surface defects that can lead to processing cracks. In order to meet the above requirements, the ultra-thin cold-rolled steel sheets used in the DI can manufacturing method should be made of continuously cast Al-killed steel slabs, and then processed through normal processes so that the crystal grains are equiaxed. It was said that For example, as stated in Japanese Patent Publication No. 55-2461 (thin steel sheets for can manufacturing), products with a grain axis ratio of 1.8 or less can significantly reduce ironing and flange forming defects. It is said that it is possible. However, the inventors further investigated the defects that occur during can manufacturing using the DI method, analyzed the causes, and classified them by cause of occurrence.
We have learned that failure to pull out and flange cracking are particularly important defects that are caused by ultra-thin cold-rolled steel sheets. When we investigated in detail what caused these defects in ultra-thin cold-rolled steel sheets, we found that the grain axis ratio had little to do with either pull-out defects or flange cracks, and that pull-out defects were caused by the grain size. It has been found that the smaller the surface, the more frequently they occur, and that there is also a relationship with the roughness of the board surface, and that they tend to occur more frequently on plates with smaller roughness. However, it has been found that flange cracking is also related to grain size, and in this case in particular, it is the opposite of defective removal, and the smaller the grain size is, the higher the defective rate is. In this contradictory relationship, the inventors succeeded in producing an ultra-thin cold-rolled steel sheet suitable for the DI can manufacturing method, which has a low rate of pull-out defects and a low rate of flange crack defects. Here, failure to pull out means that when a can body is made by pressing a cup that has been pre-formed with a punch and die in the ironing process, when the can body is pulled out from the punch after the ironing process is completed, the cup is not completely removed. In this case, if the problem is discovered late, the cups will be fed one after another at a high efficiency, causing the cups to become clogged, resulting in a large loss. The force required to separate the can body from the punch by re-drawing around the punch after drawing is called the stripping force, and the ultra-thin cold-rolled can that increases the stripping force When steel plates are used, there are many failures in stripping, and if the stripping force is increased in an attempt to forcefully pull out items with poor stripping properties, the can body may be damaged even if it comes off, resulting in such problems. Because finding and removing cans is generally difficult under high efficiency operations,
It often flows directly to the next process. Then, in the subsequent printing process, the surface of the blanket used for printing becomes flawed, resulting in a series of troubles in which the printed pattern becomes disordered. Therefore, there is a strong demand from body manufacturers to be able to strip cans with lower stripping forces and thus without damaging the cans. In order to make the can body come out easily with a smaller stripping force, it is only necessary to reduce the coefficient of friction between the inner surface of the can body after ironing and the punch surface. It is possible to improve the lubricity by allowing a large amount of the lubricating oil to remain and adhere to the can body and the punch. Therefore, it was considered that an ultra-thin cold-rolled steel sheet would be good if it could increase the roughness of the inner surface of the can body after ironing. However, from a practical point of view, it was extremely difficult to create ultra-thin cold-rolled steel sheets that would have a large degree of roughness after ironing, since they had undergone severe processing. As a result of extensive research on the above points, the inventors have proposed an ultra-thin cold-rolled steel sheet that advantageously solves these problems and has excellent can-making processability using the DI method as described below. It is something to do. First, Figure 1 shows the influence of grain size (G,
S, No) and center line roughness Ra (μ
Let me show you the effect of m).
A clear relationship was found that as the GS No. becomes larger in the range of approximately 10.0 to 11.0, that is, as the grain size becomes smaller, the values become worse in all cases. As the size decreases, which GS No.
There is also a tendency for the defective rate to increase. Next, Fig. 2 shows that the center line roughness on the inner surface of the can body after the ultra-thin cold-rolled steel sheet was ironed using various irons with different Ra and GS No. was pulled out from the punch. We organized and illustrated the relationships that affect The result was that there were fewer Furthermore, Figure 3 shows the relationship between the GS number of ultra-thin cold-rolled steel sheets and the crack failure rate when flanging after ironing. We found a tendency for this to occur frequently. From the above results, it was found that the following conditions are necessary for an ultra-thin cold-rolled steel sheet that can reduce pull-out defects and flange cracking, which are defects caused by cold-rolled steel sheets that occur during DI can manufacturing. . However, if it is too large, the crystal grains will become too thin and workability will deteriorate, so GS No. 11.0
is the upper limit. In addition, we have found that prevention of pull-out defects can be achieved by adjusting the GS No. and Ra of the ultra-thin cold-rolled steel sheet in combination, that is, by satisfying the relationship of the difference between the two (GS No. - Ra) of 9.0. Of course, in reality, the roughness of ultra-thin cold-rolled steel sheets is determined by the appearance and personal preference of the can, so first of all,
Once Ra is determined, the next step is to match the GS No. Based on the above findings, the following matters are essential for this application. The weight of this invention is C: 0.01~
Contains 0.08%, Si: 0.06% or less, P: 0.03% or less, S: 0.03% or less, Al: 0.08% or less, N;
0.015% or less, Mn within 0.5%, Mn/S
Contains an amount of ≧10, and the remainder is substantially Fe.
Finishing temperature of low carbon Al-killed steel with composition of
Hot rolled at Ar 3 transformation point or above and below 900°C, coiled at a winding temperature of 450°C to 680°C, followed by pickling and cold rolling, and then the grain size is GS No. 9.2 to 11.0.
Box annealing is performed at a temperature higher than the recrystallization temperature and lower than 680℃ so that the plate surface becomes equal to This is a method for producing ultra-thin cold-rolled steel sheets with excellent can-making processability. The reason why the composition of the ultra-thin cold-rolled steel sheet is limited in this invention will be explained below. C is an important component that suppresses the growth of recrystallized grains.If the amount of C is increased, the grain size becomes smaller and becomes harder, and the pull-out property becomes worse, which impedes DI can-making properties, so the upper limit is set at 0.08. %, and on the other hand, if the amount of C is reduced, the GS No. becomes smaller, which improves the ease of removal, but the flange cracking increases, and furthermore, when tinted, it becomes soft and has no strength against the internal pressure of the food can. 0.01 without worrying about exceeding the lower limit of the amount of C.
%. Si is a harmful component that deteriorates the corrosion resistance of tinplate, and it also makes the material extremely hard and impedes the ability to make cans using the DI method.Therefore, excessive content should be avoided, and there is no need to intentionally add it during steelmaking. If SiO 2 in the refractory is reduced by Al in the molten steel and remains, that is, 0.06% or less, it can be said to be an acceptable unavoidable impurity. P is also a component that hardens the material and deteriorates the corrosion resistance of tinplate, so excessive inclusion is undesirable, and 0.03% is an amount that can be economically removed during steel manufacturing.
The following are acceptable impurities: In relation to the amount of Mn, excessive S content may cause edge cracks in hot-rolled coils and MnS-based inclusions that may cause flange cracks, so it is not desirable to contain a large amount of S, but it is sufficient to economically desulfurize during steel manufacturing. It is an acceptable contaminating impurity of 0.03% or less. Al is an important component in the steel refining process because it plays the role of a deoxidizing agent.As the amount of Al in steel increases, the purity of the steel increases, but excessive addition Not only is it economically undesirable, but it also has the disadvantage of suppressing grain growth.
Therefore, it must be kept at 0.08% or less, and basically, if deoxidation can be completed in an amount commensurate with the amount of solid solute oxygen in molten steel, Al as metal does not necessarily need to remain in the steel. On the other hand, if the amount of Al is small, the grain size becomes large, which slightly increases flange cracking and tends to make the material soft, so the lower limit of Al amount is 0.003
% is desirable. In addition, if the amount of Al added in the steel manufacturing stage is small, the cleanliness of the steel tends to deteriorate, so in order to promote the floating separation of inclusions from the molten steel,
It is necessary to strongly stir the molten steel by vacuum degassing treatment, but in recent years this addition has almost become a process. N suppresses the growth of crystal grains and hardens the material due to precipitation of AlN and residual solid solution N. Therefore, it is desirable to reduce the amount of N to 0.015% or less, more preferably to about 0.0025%.
On the other hand, about 0.008% of N is mixed in from the air during the manufacturing process of the steel billet. Therefore, it can be easily controlled by adding Mn nitride or the like as necessary. Mn needs to be added to prevent edge cracking in the hot rolled coil, but it is controlled by the S content. The amount of Mn required to prevent ear cracking can be determined empirically by ensuring Mn/S10. Therefore, the amount of Mn is determined by the relationship with the amount of S, but the upper limit is 0.5% since there is no need to add much, and the lower limit is 0.5%.
Determined by Mn/S10. Next, in order to secure GS No. 9.2 to 11.0, the following conditions are given. First of all, steel with the above-mentioned composition range can be easily produced by various converters → vacuum degassing treatment → continuous casting, or even if the vacuum degassing treatment is omitted in this process. During rolling, the finishing temperature should be above the Ar 3 transformation point and below 900°C, and the coiling temperature should be above 450°C and below 680°C. Here, the finishing temperature is set to be higher than the Ar 3 transformation point because if it is lower than the Ar 3 transformation point, the crystal grain size increases and causes rough skin. Also 900℃
This is because if it exceeds the above, descaling performance deteriorates, surface defects due to scale increase, and the energy consumption of the heating furnace increases, making it uneconomical. On the other hand, if the coiling temperature is lower than 450℃, the steel strip will cool unevenly, making it impossible to obtain uniform quality, and the crystal grain size will become too small, making it impossible to obtain the specified GS No. even if box annealing is performed. , the winding temperature is 680
The reason for this limitation is that if the temperature exceeds .degree. C., the crystal grain size becomes too large and the descaling property deteriorates, making surface defects more likely to occur. The steel strip obtained in this way is pickled and cold rolled to the desired product thickness, and then the composition, finishing temperature, and coiling temperature are determined from the range of recrystallization temperature to 680℃. Box annealing is performed at a temperature selected so that the crystal grain size becomes 9.2 to 11.0 in GS No. according to the conditions, recrystallization and grain size growth are performed to obtain a predetermined crystal grain size. In this case, the box annealing temperature is, for example, the winding temperature.
When the winding temperature is low in the range of 450 to 680°C, it is relatively high, and when the winding temperature is high, it is relatively low, so that a predetermined crystal grain size can be easily obtained. The reason why the box annealing temperature was set to 680° C. or lower is that if the temperature is higher than this, the crystal grain size becomes coarse and a predetermined crystal grain size cannot be obtained. By controlling the above process conditions, GS No.
9.2-11.0 is easily obtained. Furthermore, simply adjusting the GS No. alone cannot reduce defects, and after various studies, we found that the only way to prevent defects is to adjust the GS No. and surface roughness Ra (μ
We found that this can be achieved by combining and adjusting m), that is, by satisfying the relationship of the difference between the two (GS No. - Ra) of 9.0. Here, the surface roughness Ra means the center line average roughness according to JISB0601, and is the value at a cutoff value of 0.8 mm and a measurement length of 2.5 mm. Figure 4 shows the relationship between GS No.-Ra and defective rate. As is clear from FIG. 4, by setting GS No.-Ra to 9.0 or less, the defect rate can be significantly reduced. Next, the surface roughness of the ultra-thin cold-rolled steel sheet is determined by the work roll roughness of the temper rolling mill, which is determined by the roll roughness x the transfer rate. Therefore, a steel plate with the required roughness can be easily obtained by using a roll having an appropriate roughness. Of course, in reality, the roughness of ultra-thin cold-rolled steel sheets is determined by the appearance, appearance, and taste of the can.
First, Ra is determined, and then GS No. is matched. On the other hand, a predetermined GS No. can be obtained by controlling the above-described component composition, finishing temperature, winding temperature, and box annealing temperature. Next, the hardness of the ultra-thin cold-rolled steel sheet was determined by the Rockwell Steel hardness test as a can manufacturing material using the DI method.
46 on the 30T scale (expressed as HR30T)
Fits in the range of ~60. The materials required for the can material are determined by the state of the can, i.e., the state in which the can is filled with contents. In other words, the strength required for a can body is determined by the internal pressure strength of the can, and the internal pressure strength changes depending on the filling material. For example, it differs depending on the contents of the can, such as beer and carbonated drinks, which generate gas and increase the internal pressure of the can, and those that do not emit gas, such as vegetable juices. Therefore, materials with different hardnesses are required for DI cans, and for that reason, the above-mentioned
HR46~60 means T1 (HR30T: 46~52), T2
(50 to 56), T21/2 (52 to 58), and T3 (54 to 60), and the hardness range for each category is determined by the manufacturing conditions described above depending on the use of the cold rolled steel sheet. This can be achieved by recommending the following, and taking this into consideration when performing temper rolling and tinting of cold-rolled steel sheets. For test numbers 1 to 3 in which raw steel was melted in a converter and the C content was 0.01% with the steel plate components shown in Table 1,
After performing vacuum degassing treatment, the remaining samples were made into steel slabs using a continuous casting machine, and then hot-rolled into 2.6 mm coils using a hot rolling mill under the conditions shown in the table. After pickling and descaling, the material was rolled to an extremely thin plate thickness of 0.3 mm using a 6-stand tandem cold rolling mill, and then box annealed under the conditions listed in the table. Next, skin pass rolling was performed in a skin pass rolling mill using work rolls with different roll roughnesses at a reduction rate of 1.5 ± 0.5% and various sheet surface roughnesses.
【表】【table】
【表】
各極薄冷延鋼板にはハロゲンタイプの錫めつき
工程にて＃25錫めつきを行い、板面あらさが1.5
μｍRa以下のものについては通常の溶錫化処理
を連続して直ちに施し、それよりあらさの大きい
ものは溶錫化処理を施さないで、何れもDI法に
よる製缶用原板とした。
各供試原料の硬さを測定した後、DI法にて250
ml炭酸飲料缶をつくり、その際原板の性状に起因
する抜け不良とフランジ不良率を調べ、総合評価
を行つた。加えて表１にあわせ掲げた。
表１に示す成績から明らかなように、この発明
による極薄冷延鋼板は、結晶粒度や板面あらさの
外れた比較鋼板に比してDI製缶成績がとくに抜
け不良率およびフランジ割れ不良率に関しはるか
にすぐれている。
かくしてこの発明の製造方法によつて得られた
極薄冷延鋼板は、DI法による製缶の際とくに問
題となる抜け不良およびフランジ割れの相克的な
背反条件を有利に脱却して、DI法の高能率操業
に、有利に適合する。[Table] Each ultra-thin cold-rolled steel plate is tinned with #25 tin using a halogen type tin plating process, and the plate surface roughness is 1.5.
Those with a roughness of less than μmRa were immediately and continuously subjected to the usual hot tin treatment, and those with greater roughness were not subjected to the hot tin treatment, and both were used as original plates for can making by the DI method. After measuring the hardness of each sample material, 250
ml carbonated beverage cans were made, and the failure rates due to the properties of the base plate and the flange failure rate were investigated and a comprehensive evaluation was performed. In addition, they are listed in Table 1. As is clear from the results shown in Table 1, the ultra-thin cold-rolled steel sheet according to the present invention has a particularly high DI can making performance in terms of pull-out defect rate and flange crack defect rate, compared to comparative steel sheets with different grain sizes and plate surface roughness. It is far superior in terms of Thus, the ultra-thin cold-rolled steel sheet obtained by the manufacturing method of the present invention advantageously overcomes the contradictory conditions of pull-out failure and flange cracking, which are particularly problematic when making cans using the DI method, and can be manufactured using the DI method. advantageously suited for high-efficiency operation.
第１図は抜け不良発生率に及ぼす極薄冷延鋼板
の結晶粒度と板面あらさとの影響を示すグラフ、
第２図は抜け不良発生率に関するしごき加工後の
缶体内面あらさとの関係を示すグラフ、第３図は
フランジ割れ発生率と極薄冷延鋼板の結晶粒度と
の関係を示すグラフである。第４図は抜け不良率
と極薄冷延鋼板の（GSNo.―Ra）との関係を示す
グラフである。
Figure 1 is a graph showing the influence of grain size and plate surface roughness of ultra-thin cold-rolled steel sheets on the incidence of pull-out defects.
FIG. 2 is a graph showing the relationship between the occurrence rate of pull-out defects and the roughness of the inner surface of the can body after ironing, and FIG. 3 is a graph showing the relationship between the incidence of flange cracking and the grain size of ultra-thin cold-rolled steel sheets. FIG. 4 is a graph showing the relationship between the pull-out defect rate and (GS No.-Ra) of an ultra-thin cold-rolled steel sheet.
Claims (1)
以下、Ｐ：0.03％以下、Ｓ：0.03％以下、Al：
0.08％以下、Ｎ：0.015％以下であつてMnを0.5％
以内、Mn／Ｓ≧10となる量において含有し、残
部実質的にFeの組成からなる低炭素Alキルド鋼
を、仕上げ温度Ar3変態点以上、900℃以下で熱
間圧延し、巻取り温度450℃〜680℃で巻取り、続
いて酸洗後冷間圧延を行ない、次いで結晶粒度が
GSNo.で9.2〜11.0になるよう再結晶温度以上680℃
以下の温度で箱焼鈍し、続いて前記GSNo.と板面
の中心線平均あらさをあらわすRa（μｍ）との
差が9.0以下になるよう調質圧延を施すことを特
徴とする製缶加工性に優れる極薄冷延鋼板の製造
方法。1 Contains C: 0.01-0.08% by weight, Si: 0.06%
Below, P: 0.03% or less, S: 0.03% or less, Al:
0.08% or less, N: 0.015% or less, and Mn 0.5%
A low carbon Al-killed steel containing Mn/S≧10, with the remainder essentially consisting of Fe, is hot-rolled at a finishing temperature of Ar 3 transformation point or higher and 900°C or lower, and then rolled at a coiling temperature of Coiling at 450℃~680℃, followed by cold rolling after pickling, then grain size
680℃ above the recrystallization temperature so that the GS No. is 9.2 to 11.0
Can manufacturing processability characterized by box annealing at the following temperature, followed by skin pass rolling so that the difference between the GS No. and Ra (μm), which represents the average roughness of the center line of the plate surface, is 9.0 or less A method for producing ultra-thin cold-rolled steel sheets with excellent properties.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2277182A JPS58141364A (en) | 1982-02-17 | 1982-02-17 | Extremely-thin cold-rolled steel plate with superior workability into can |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2277182A JPS58141364A (en) | 1982-02-17 | 1982-02-17 | Extremely-thin cold-rolled steel plate with superior workability into can |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58141364A JPS58141364A (en) | 1983-08-22 |
| JPS6214202B2 true JPS6214202B2 (en) | 1987-04-01 |
Family
ID=12091927
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2277182A Granted JPS58141364A (en) | 1982-02-17 | 1982-02-17 | Extremely-thin cold-rolled steel plate with superior workability into can |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58141364A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59173240A (en) * | 1983-03-22 | 1984-10-01 | Nippon Steel Corp | Steel plate for high strength easy-open can lid excellent in can opening property |
| JPS6134159A (en) * | 1984-07-25 | 1986-02-18 | Nippon Steel Corp | Steel sheet for weld can superior in flanging property and its manufacture |
| JPS61272347A (en) * | 1985-05-28 | 1986-12-02 | Nippon Steel Corp | Hot-rolled steel sheet excelling in press formability and baking hardening |
| JPH02263949A (en) * | 1989-04-03 | 1990-10-26 | Toyo Kohan Co Ltd | Steel sheet for di can |
| JP2640057B2 (en) * | 1991-07-29 | 1997-08-13 | 東洋鋼鈑株式会社 | Single side coated steel sheet for DI can |
| CN104975225A (en) * | 2015-07-14 | 2015-10-14 | 山东众冠钢板有限公司 | High-strength and corrosion-resistance SPHC steel plate and preparing method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5751448A (en) * | 1980-04-18 | 1982-03-26 | Gunze Kk | Manufacture of gasset from cylindrical film |
-
1982
- 1982-02-17 JP JP2277182A patent/JPS58141364A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5751448A (en) * | 1980-04-18 | 1982-03-26 | Gunze Kk | Manufacture of gasset from cylindrical film |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58141364A (en) | 1983-08-22 |
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