JPS61238427A - Manufacture of drawn, ironed can having good corrosion resistance by coating - Google Patents

Abstract

PURPOSE:To improve lubricity and corrosion resistance of cans by specifying a combination of a surface roughness of steel plates before working with a surface roughness of a punch to be used in working. CONSTITUTION:A forming is performed under the combination of a surface roughness of steel plates before the forming being <=0.4mum Ra with a surface roughness of a punch to be used in ironing being <=0.2mum Ra. A good coating percentage of tin, etc. applied to the surface of steel plates is maintained after the forming, so that a highest corrosion resistance and lubricity by coating is provided by the above method.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は絞シ成形と、しごき加工を組合せて成形される
成形缶（Ｄｒａｖｒ　＆　Ｉｒｏｎｉｎｇ成形の頭文字
を用い以下ＤＩ缶と称す）の製造方法に関するものであ
る。[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to the production of molded cans (hereinafter referred to as DI cans using the initials of Dravr & Ironing molding) that are molded by a combination of drawing and ironing. It is about the method.

（従来の技術） 周知の如くビールあるいは炭ｉ飲料水用の充填容器とし
てアルミニウムあるいはブリキを素材として絞シ・しご
き加工によるＤＩ缶が金属容器として多用されている。(Prior Art) As is well known, DI cans made of aluminum or tin and drawn and ironed are often used as metal containers for beer or charcoal drinking water.

ブリキの場合、表面にメッキされた錫が加工時の有効な
潤滑剤として作用するが更に素地である鋼板表面粗度が
重要視されている。例えば現在商業的に生産されている
ＤＩ缶用ブリキは全て０．６μｍＲｍ以上の表面粗度に
て生産されており、加工前の鋼板表面粗度を大きくする
事によって潤滑油の持ちこみを容易にし、しごき加工時
の潤滑性を向上させる事が最も大きな目的となっている
。このように加工用鋼板の表面を粗面にして潤滑剤を保
持する考え方は特開昭４９−７５４５７号公報でも提案
されている。一方、しごき加工用のノ々ン千表面を製缶
メーカの独自の技術に基き、粗い表面もあれば比較的滑
らかな表面を使用している所もあり必ずしも技術的に統
一された思想がない現状である。In the case of tinplate, the tin plated on the surface acts as an effective lubricant during processing, but even more important is the surface roughness of the steel plate. For example, all tinplates for DI cans that are currently commercially produced are produced with a surface roughness of 0.6 μmRm or higher, and by increasing the surface roughness of the steel plate before processing, lubricating oil can be carried in easily. The main purpose is to improve lubricity during ironing. The concept of roughening the surface of a working steel plate to retain lubricant in this manner has also been proposed in Japanese Patent Laid-Open No. 75457/1983. On the other hand, the nonansen surface for ironing is based on the proprietary technology of can manufacturers, and some use rough surfaces while others use relatively smooth surfaces, and there is not necessarily a unified technical philosophy. This is the current situation.

（発明が解決しよ、うとする問題点） 近年、材料コスト低減のためＤＩ缶用ブリキの付着量は
従来の＋５０ブリキ（錫付着量として５．７１１／ｌｆ
）よシナ２５更には＋１０ブリキへと錫付着量を低減す
る方向にある。その際、潤滑性の低下に伴いしごき加工
時のダイス寿命の低下が起シ大きな問題となっている。(Problem that the invention attempts to solve) In recent years, in order to reduce material costs, the amount of tin plate for DI cans has been increased from the conventional tin plate by +50 (5.711/lf as the amount of tin coated)
) The trend is to reduce the amount of tin deposited to 25% tinplate and even 10% tinplate. At that time, a reduction in the life of the die during ironing due to the reduction in lubricity has become a major problem.

一方、缶内面側においては錫メツキ皮膜の、加工による
破壊が起シ耐食性劣化をもたらす事になる。この耐食性
問題は錫付着量の低減と共に非常に大きな問題であｆｉ
　ＤＩ缶底成形後内面塗装をよシ完全なものとする必要
性が生ずる事となる。本発明者らの着眼点は、ブリキの
錫メツキ皮膜はメッキ時点では極めて欠陥の少い皮膜で
あるにもかかわらずＤＩ前加工よシ激しくダメージを受
ける所に着目し、錫メツキ皮膜をこわさずに加工する方
法は何かを追求した所にある。On the other hand, on the inner surface of the can, the tin plating film is destroyed due to processing, resulting in deterioration of corrosion resistance. This corrosion resistance problem is a very big problem along with the reduction of tin adhesion.
After forming the bottom of the DI can, it becomes necessary to completely coat the inner surface of the can. The inventors focused their attention on the fact that the tin plating film on tinplate is severely damaged by pre-DI processing, even though it has very few defects at the time of plating. The method of processing it lies in the pursuit of something.

即ち、本発明が解決しようとする問題点は、ＤＩ成形後
の缶内外面における錫メツキ皮膜の均一性を大幅に改善
する所にある。That is, the problem to be solved by the present invention is to significantly improve the uniformity of the tin plating film on the inner and outer surfaces of the can after DI molding.

（問題点を解決するための手段） 本発明者らは、前記の問題点を解決することを目的とし
てＤＩ缶における加工条件につき詳細な検討を行った結
果、潤滑性及び耐食性向上に対し最も望ましい加工条件
が存在する事を見出した。(Means for Solving the Problems) In order to solve the above-mentioned problems, the present inventors conducted a detailed study on the processing conditions for DI cans, and found that the most desirable method for improving lubricity and corrosion resistance. It was discovered that processing conditions exist.

即ち本発明の要旨は加工前の鋼板表面粗度を０、４μｍ
Ｒａ以下、しごき加工に使用するノクンチの表面粗度を
０．２μｍＲａ以下にして成形することを特徴とする絞
り、しごき加工缶の製造法である。In other words, the gist of the present invention is to reduce the surface roughness of the steel sheet before processing to 0.4 μm.
This is a method for manufacturing a drawn and ironed can, characterized in that the surface roughness of the Nokunchi used for ironing is 0.2 μm or less.

以下、本発明の詳細な説明する。The present invention will be explained in detail below.

まず本発明における第１の重要点は鋼板表面粗度の規制
にあり、圧延方向（以下り方向と称す）及び圧延方向と
直角の方向（以下Ｃ方向と称す）にて測定された表面粗
度が平均粗さにおいてＯ５４μｍＲａ以下である事を必
要とする。◆２５ブリキの場合、その平均メッキ厚みは
約０．４μｍであシナ１０ブリキになると、０．１５４
μｍの平均厚みとなシ非常にメッキ厚みが薄いため０．
４μｍＲａをこえる粗い表面粗度ではメッキ時点にて微
細なメッキ欠陥（ピンホール）の数を増加させる事にな
シ好ましくない。メッキされた錫は溶融しない方がＤＩ
成形時の潤滑には好ましいが、外観的に光沢の優れたも
のが必要な場合には溶融を行うが、その場合は出来るだ
け錫−鉄合金層の形成を抑え、望ましくは合金錫量とし
て３００ｍ９／−以下とする事が必要である。又、材質
的には絞シ成形時の板厚変化を小さくし缶内周方向での
均一性を高めるためランクフォード値（ｒ値）は１．４
以上のものが望ましい。又、通常黄変防止あるいは塗料
密着性向上のために施される化学処理皮膜はＤＩ成形時
の潤滑性を阻害するため最低限、例えばＣｒ付着量とし
て５ｒｎｔ）７ｍ　”以下に抑える事が望ましい。First, the first important point in the present invention is the regulation of the surface roughness of the steel plate, and the surface roughness measured in the rolling direction (hereinafter referred to as the down direction) and the direction perpendicular to the rolling direction (hereinafter referred to as the C direction). is required to have an average roughness of O54 μmRa or less. ◆In the case of 25mm tinplate, the average plating thickness is about 0.4μm, and for 10mm tinplate, it is 0.154μm.
Since the average thickness of the plating is very thin, the average thickness is 0.
If the surface roughness exceeds 4 μmRa, it is undesirable to increase the number of fine plating defects (pinholes) at the time of plating. DI is better if plated tin does not melt.
It is preferable for lubrication during molding, but if a product with excellent gloss is required, melting is performed, but in that case, the formation of a tin-iron alloy layer is suppressed as much as possible, and the amount of tin alloy is preferably 300 m9. /- It is necessary to do the following. In addition, in terms of the material, the Lankford value (r value) is 1.4 in order to reduce the change in plate thickness during drawing forming and improve uniformity in the inner peripheral direction of the can.
The above is desirable. Furthermore, since the chemically treated film usually applied to prevent yellowing or improve paint adhesion impedes lubricity during DI molding, it is desirable to keep the amount of Cr deposited to a minimum of, for example, 5rnt)7m'' or less.

この様にして作成されたブリキはＤＩ缶成形に供しうる
が耐食性を向上するためにはさらにＤＩ成形条件の限定
が必要である。ビール缶、炭酸飲料缶の場合、通常０．
２８〜０．３２”の板厚のものを絞り、しごき加工によ
り０．０９〜０，１０■にまで加工するが。Although the tin plate produced in this manner can be subjected to DI can molding, it is necessary to further limit the DI molding conditions in order to improve the corrosion resistance. In the case of beer cans and carbonated drink cans, it is usually 0.
A plate with a thickness of 28 to 0.32" is drawn and ironed to a thickness of 0.09 to 0.10".

この他の内容物（非内圧缶）の場合、缶強度が必要なた
め０．１５〜０．２０■程度にまで加工する。板厚減少
はしごき加工により行われるが、しごき加工に用いるパ
ンチの表面性状は非常に重要である。In the case of other contents (non-internal pressure cans), the strength of the can is required, so it is processed to a strength of about 0.15 to 0.20 . The plate thickness is reduced by ironing, and the surface quality of the punch used in ironing is very important.

缶外面の場合、しごき加工の進行につれその表面は平滑
になってゆくが缶内面の場合ノ臂ンチ表面がそのまま転
写される事となシ加工後の缶内面の表面状態はパンチ表
面にて決定される。その際加工前の原板表面粗度とノ臂
ンチ表面粗度の組合せにより加工後の缶内面における錫
の分布状態は非常に大きく変化する。原板の表面粗度が
粗い場合と微小粗度の・ぐンチ表面を採用しても均一な
錫分布は得られない。又、パンチ表面が粗い場合、鋼板
表面粗度を微小にしても錫の被覆性が劣る事となシ良好
な耐食性を得る事は困難である。In the case of the outer surface of a can, the surface becomes smooth as ironing progresses, but in the case of the inner surface of a can, the surface of the arm punch is transferred as is.The surface condition of the inner surface of the can after ironing is determined by the surface of the punch. be done. At this time, the distribution state of tin on the inner surface of the can after processing changes greatly depending on the combination of the surface roughness of the original plate before processing and the surface roughness of the notch. Uniform tin distribution cannot be obtained when the surface roughness of the original plate is rough or when a finely rough surface is used. Furthermore, if the punch surface is rough, even if the surface roughness of the steel plate is made minute, the tin coverage will be poor and it will be difficult to obtain good corrosion resistance.

缶外面においては前述したようにしごき加工の進展と共
に、表１に示した如く、表面粗度は徐々に低下してゆく
ため、特に加工の厳しいビール、炭酸飲料缶においては
加工前の鋼板表面粗度は有効な作用を果しえない。即ち
、しごき加工の初期段階において表面粗度差が実質的に
なくなってしまうため、潤滑油の持ちこみ（パンチルダ
イス間）に差がなくなるため表面粗度による潤滑性の向
上は期待できない事となる。従りて、缶外面においても
錫の均一分布による潤滑性（かじり防止作用）を期待す
る方が合理的である。また缶外面における錫の分布状態
においても加工前の鋼板表面粗度低下は極めて有効であ
る。As shown in Table 1, the surface roughness of the outer surface of the can gradually decreases as the ironing process progresses, as shown in Table 1. Degrees cannot play an effective role. That is, since the difference in surface roughness is substantially eliminated in the initial stage of ironing, there is no difference in lubricant carry-over (between punch and die dies), so improvement in lubricity due to surface roughness cannot be expected. Therefore, it is more reasonable to expect lubricity (anti-galling effect) due to the uniform distribution of tin on the outer surface of the can. Also, reducing the surface roughness of the steel plate before processing is extremely effective in controlling the distribution of tin on the outer surface of the can.

以下本発明の実施例を述べる。Examples of the present invention will be described below.

〔実施例１〕 板厚０．３２”の焼鈍板を調質圧延時に表面粗度の異な
るロールにて圧延して表面粗度の調整を行い、３水準の
鋼板表面粗度を得た。この鋼板に１．７ｊＪ／ｍ”の電
気錫メッキを行った。錫メッキ（溶融処理なし）後、重
クロム酸ソーダ（３チ、４５℃）中に１　ｓ＠ｅ浸漬の
化学処理後、水洗・乾燥したものを２段の絞り加工及び
３段のしごき加工により０、１　”の側壁を有するＤＩ
缶に成形した。成形後の缶外面における錫の分布状態を
Ｘ線マイクロアナライデーで分析し、錫の被覆率を比較
した所、表２に示す結果が得られた。[Example 1] During temper rolling, an annealed plate with a thickness of 0.32" was rolled with rolls having different surface roughness to adjust the surface roughness, and three levels of steel plate surface roughness were obtained. The steel plate was electroplated with tin at a rate of 1.7jJ/m''. After tin plating (no melting treatment), chemical treatment of 1 s@e immersion in sodium dichromate (3 chloride, 45°C), washing and drying, followed by 2 stages of drawing and 3 stages of ironing. DI with sidewalls of 0,1”
Molded into a can. The state of distribution of tin on the outer surface of the can after molding was analyzed using an X-ray microanalyzer and the coverage of tin was compared, and the results shown in Table 2 were obtained.

表２に示す如く原板表面粗度の小さい材料は優れた錫被
覆性を示し、かじシの発生傾向も少なく優れたものであ
りた。As shown in Table 2, materials with low surface roughness of the original plate showed excellent tin coverage and had a low tendency to generate scratches.

〔実施例２〕 実施例１と同様に３種類の異った表面粗度を有する原板
を用いてブリキを作成し、ＤＩ成成形用２痒 チの表面粗度を２種類（０．１　　　と０．５μｍＲａ
　）準備し、合計６種類の組合せによる成形テストを行
った。使用したブリキ板の板厚は０．３２”、ＤＩ成形
後の缶壁の板厚は０．１０４簡であった。成形後の缶壁
内面の錫分布状態及び炭酸飲料中での鉄溶出挙動を表３
及び第１図に示す。[Example 2] As in Example 1, tinplates were made using original plates with three different surface roughnesses, and two types of surface roughness (0.1 and 0.1) were used for DI molding. 0.5μmRa
) were prepared and a molding test was conducted using a total of 6 types of combinations. The thickness of the tin plate used was 0.32", and the thickness of the can wall after DI molding was 0.104". Tin distribution state on the inner surface of the can wall after molding and iron elution behavior in carbonated drinks. Table 3
and shown in FIG.

表３　成形缶内面の錫被覆率（＋５０ブリキ使用）表３
にみられる如く、本発明に係るパンチ表面粗度０．　１
μ−員と、ブリキ表面粗度０．２μｍＲａ（原板粗度は
０．　３μｍＲａ　）の組合せによる成形缶は極めて優
れた錫被覆性を示している。Table 3 Tin coverage rate on the inner surface of the molded can (+50 tin plate used) Table 3
As can be seen, the punch surface roughness according to the present invention is 0. 1
A molded can formed by a combination of .mu.-member and tin plate surface roughness of 0.2 .mu.mRa (original plate roughness of 0.3 .mu.mRa) exhibits extremely excellent tin coverage.

第１図は缶壁内面側を無塗装（市販の飲料缶の場合内面
塗装有）にて５５℃に保たれた炭酸飲料水（商標名スゲ
ライト）中に浸漬し，鉄の溶出量を経時的に測定したも
ので試料屋は表３に対応している。本発明に係る成形缶
（サンプルム■）は他サンプルに比較すると１／１０〜
１１５０の鉄溶出量しか示さなかった。Figure 1 shows the amount of iron eluted over time by immersing the inner surface of the can wall without coating (commercially available beverage cans have inner surfaces coated) in carbonated drinking water (trade name Sugelite) kept at 55℃. The samples were measured in accordance with Table 3. The molded can according to the present invention (Samplem ■) is 1/10 to 1/10 compared to other samples.
The iron elution amount was only 1150.

（発明の効果） 以上詳述したとおシ、本発明は鋼板表面粗度とＤＩＩ工
用パンチ粗度の組合せによって最高の耐食性、潤滑性を
得る事を可能にしたものであシ、ブリキ以外の表面皮膜
を有するＤＩＩ工用鋼板についても有効である事はいう
までもない事である。(Effects of the Invention) As detailed above, the present invention makes it possible to obtain the highest corrosion resistance and lubricity by combining the surface roughness of the steel plate and the roughness of the DII punch. Needless to say, this method is also effective for DII steel sheets that have a surface coating.

【図面の簡単な説明】 第１図は実施例２の表３に示す内面側゛無塗装の成形缶
（試料屋■〜■）の炭酸飲料水（５５℃）中における浸
漬時間と鉄溶出量の関係を示す図である。 浸：嚢吟閘　（日）[Brief explanation of the drawings] Figure 1 shows the immersion time and amount of iron eluted in carbonated drinking water (55°C) of molded cans with unpainted inner surface (sample shop ■~■) shown in Table 3 of Example 2. FIG. Immersion: Ginjo (Japanese)

Claims (1)

【特許請求の範囲】[Claims] 絞りとしごき加工により缶体を成形するに際して、加工
前の鋼板表面粗度を０．４μｍＲａ以下、しごき加工に
使用するパンチの表面粗度を０．２μｍＲａ以下にして
成形することを特徴とする塗装耐食性の良好な絞り、し
ごき加工缶の製造法。A coating characterized in that when forming a can body by drawing and ironing, the surface roughness of the steel plate before processing is 0.4 μmRa or less, and the surface roughness of the punch used for ironing is 0.2 μmRa or less. A method for producing drawn and ironed cans with good corrosion resistance.