JPH08337849A - Production of easily can-openable cover - Google Patents

Abstract

PURPOSE: To produce an easily can-openable cover capable of easily opening by hands by subjecting a steel sheet having a specified compsn. and excellent in corrosion resistance to pressure molding by dies for forming cutting guide grooves in which the radius of the shoulder and clearance are specified. CONSTITUTION: The compsn. of a steel sheet being a stock is composed of, by weight, <=0.02% C, <=0.3 Si, <=0.5% Mn, <=0.025% P, <=0.025% S, 0.02 to 0.15% acid soluble Al, Ti; four times or above the content of C and also by 0.02 to 0.30%, 5.5 to 10% Cr, and the balance Fe with inevitable impurities. The steel sheet is subjected to pressure molding by using dies in which the shoulder radius of the upper and lower dies for forming cutting guide grooves constituting an opening-sided shape is regulated to 0.1 to 1.0mm and the clearance between a punch and the dies is regulated to 0.6 to 1.6mm to form cutting guide grooves by the shoulder radius of both dies. At the time of the working, the circumferential part of the opening side is pressurized between the dies to form a thin part. The cutting guide grooves in which the thickness of the metal in the thinnest part is regulated to 1/2 of that of the metal before the working can be formed.

Description

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

【０００１】[0001]

【産業上の利用分野】本発明は、金属容器蓋、特に缶蓋
の一部あるいはほぼその全面に人手により容易に開口で
きる易開缶性蓋の製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal container lid, and more particularly to a method for producing an easily openable lid which can be easily opened by hand on a part or almost the entire surface of a can lid.

【０００２】[0002]

【従来の技術】従来、容器蓋の一部を人手により容易に
開口できる易開缶性蓋は、蓋本体を平らな下型上に載
せ、その上面より所要の輪郭形状を有する尖鋭刃を押圧
して、その刃先を蓋本体へ食い込ませることにより、断
面Ｖ字型の切断案内溝を形成し、開口形状を得ていた。
しかし、この方法では刃先が鋭角なため、防食のため、
予め塗布された塗装膜が破壊され、スチール製の蓋の場
合、その後補修塗装が必要になり製造コストを高くして
いた。また鋼板においては、尖鋭刃の激しい加工である
ため、工具寿命がもたない欠点があった。2. Description of the Related Art Conventionally, an easily openable lid which can easily open a part of a container lid manually is placed on a flat lower mold, and a sharp blade having a required contour shape is pressed from the upper surface thereof. Then, by cutting the blade edge into the lid body, a cutting guide groove having a V-shaped cross section was formed to obtain an opening shape.
However, with this method, the cutting edge is sharp, so for corrosion protection,
The coating film applied in advance was destroyed, and in the case of the lid made of steel, repair coating was required after that, which increased the manufacturing cost. Further, in the case of a steel plate, there is a drawback that the tool life is short because the sharp blade is severely processed.

【０００３】工具寿命の延長対策としては、特開昭５５
−７０４３４３号公報、特開昭５７−１７５０３４号公
報に見られるように、複合押し出し加工により、切断案
内溝を構成する方法が提案されている。しかし、この方
法では通常の鋼板を使用する限り、切断案内溝部の加工
により、塗料が剥がれ金属案内溝が露出した部分には、
スプレー塗装が必要であった。As a measure for extending the tool life, Japanese Patent Laid-Open No. Sho 55 has been proposed.
As disclosed in JP-A-704343 and JP-A-57-175034, a method of forming a cutting guide groove by a composite extrusion process has been proposed. However, in this method, as long as a normal steel plate is used, the coating is peeled off and the metal guide groove is exposed by the processing of the cutting guide groove,
Spray painting was needed.

【０００４】一方、防食対策として、低炭素のチタン添
加鋼にＣｒを５．５〜１０．０重量％未満含有させ、か
つ特定量の酸可溶Ａｌを加えた低Ｃｒ鋼を用いれば、耐
食性に優れた易開缶性蓋ができる可能性がある。しか
し、上記の尖鋭刃による断面Ｖ字型の切断案内溝の成形
に関しては、断面Ｖ字型の加工部の塗料が剥がれ、かつ
その加工部に歪みが集中するため、Ｖ字型直下に錆が発
生するという問題があった。On the other hand, as an anticorrosion measure, if a low Cr steel containing Cr in an amount of less than 5.5 to 10.0% by weight in a low carbon titanium-added steel and adding a specific amount of acid-soluble Al is used, There is a possibility that an excellent easily openable lid can be created. However, regarding the formation of the cutting guide groove having a V-shaped cross section by the above-mentioned sharp blade, the paint on the processed portion having the V-shaped cross section is peeled off, and the strain is concentrated on the processed portion, so that rust is formed immediately below the V-shaped portion. There was a problem that it occurred.

【０００５】[0005]

【発明が解決しようとする課題】本発明は上記問題点を
解消するものであって、切断案内溝に錆が発生せず、か
つ開缶性の良好なスチール製の易開缶性蓋を提供するこ
とを目的とする。DISCLOSURE OF THE INVENTION The present invention solves the above problems and provides a steel easy-open can lid which does not rust in the cutting guide groove and has good can openability. The purpose is to do.

【０００６】[0006]

【課題を解決するための手段】本発明は、上記目的を達
成するためになされたものであり、開口片形状を構成す
る切断案内溝形成用上下金型の肩半径が、０．１〜１．
０mmで、かつクリアランスを−０．６mm〜１．６mmとし
た金型を用い、上下金型の該肩半径部分にて、所定の成
分の低炭素のチタン添加鋼にＣｒを５．５〜１０．０重
量％未満含有し、かつ特定量の酸可溶Ａｌを含ませた耐
錆性に優れた鋼板を押圧加工成形し、加工による最薄部
の金属厚みを加工前の金属厚みの１／２以下に薄くする
ことにより切断案内溝を形成することを特徴とする易開
缶性蓋の製造方法である。The present invention has been made in order to achieve the above-mentioned object, and the shoulder radii of the upper and lower molds for forming the cutting guide groove forming the opening piece shape are 0.1 to 1. ．
Using a mold having a diameter of 0 mm and a clearance of -0.6 mm to 1.6 mm, Cr is added to a low carbon titanium-added steel having a predetermined composition with Cr of 5.5 to 10 at the shoulder radius portions of the upper and lower molds. A steel sheet containing less than 0.0% by weight and containing a specific amount of acid-soluble Al and having excellent rust resistance is press-formed, and the metal thickness of the thinnest part is 1 / th of the metal thickness before processing. A method for manufacturing an easily openable lid is characterized in that a cutting guide groove is formed by thinning the thickness to 2 or less.

【０００７】以下に本発明を詳細に説明する。本発明は
素材と加工方法の組み合わせにより達成される発明であ
る。先ず素材について説明する。本発明に使用する鋼板
は、通常、板厚ｔ₀ ：０．１５０〜０．３００mmの範囲
にある。鋼成分は、重量％として、Ｃ：０．０２％以
下、Ｓｉ：０．３％以下、Ｍｎ：０．５％以下、Ｐ：
０．０２５％以下、Ｓ：０．０２５％以下、酸可溶Ａ
ｌ：０．０２〜０．１５％、Ｔｉ：Ｃ量の４倍でかつ
０．０２％以上０．３０％以下、Ｃｒ：５．５〜１０％
未満、である。また必要に応じＣｕ：０．０１〜０．５
０％、Ｎｉ：０．０１〜０．５０％の１種または２種を
含有させ、残部は鉄及び不可避的不純物からなる。The present invention will be described in detail below. The present invention is an invention achieved by combining a material and a processing method. First, the material will be described. The steel plate used in the present invention usually has a plate thickness t _{0 of} 0.150 to 0.300 mm. The steel composition, as weight%, is C: 0.02% or less, Si: 0.3% or less, Mn: 0.5% or less, P:
0.025% or less, S: 0.025% or less, acid-soluble A
1: 0.02 to 0.15%, Ti: 4 times the amount of C and 0.02% to 0.30%, Cr: 5.5 to 10%
Is less than. If necessary, Cu: 0.01 to 0.5
0%, Ni: 0.01 to 0.50% of 1 type or 2 types are contained, and the balance consists of iron and unavoidable impurities.

【０００８】Ｃは０．０２％を超えると耐食性が悪くな
り、本発明の目的を達成し得ない。望ましくは０．０１
％以下で低ければ低いほどよく下限値は定めない。Ｓ
ｉ，Ｍｎは製鋼上必要な成分であるが多量に含まれると
加工性が劣化するので、Ｓｉは０．３％以下、Ｍｎは
０．５％以下とした。しかし、高水準の加工性を維持す
るためにはＳｉは０．１％以下、Ｍｎは０．３５％以下
が望ましい。Ｐ及びＳはできる限り低い方が、耐食性や
加工性によい結果をもたらすが製鋼作業の経済的制約か
らそれぞれ、０．０２５％以下に限定した。When C exceeds 0.02%, the corrosion resistance is deteriorated, and the object of the present invention cannot be achieved. Desirably 0.01
The lower limit is less than%, and the lower limit is not defined. S
Although i and Mn are components necessary for steelmaking, if they are contained in a large amount, workability deteriorates, so Si is set to 0.3% or less and Mn is set to 0.5% or less. However, in order to maintain a high level of workability, Si is preferably 0.1% or less and Mn is 0.35% or less. When P and S are as low as possible, good results can be obtained in corrosion resistance and workability, but they were limited to 0.025% or less due to economic constraints of steelmaking work.

【０００９】Ｔｉは各種の成形に必要な加工性を付与す
るために必要であるが、耐食性を確保するために必要な
含有量としては、０．０２％以上、０．３０％以下でか
つＴｉ／Ｃで４以上が必要である。０．３０％より多く
することは再結晶温度を上げ、製造コストも高くなるば
かりである。好ましくは０．１％以下がよい。[0009] Ti is necessary for imparting workability necessary for various moldings, but the content necessary for ensuring corrosion resistance is 0.02% or more and 0.30% or less and Ti / C needs to be 4 or more. If it is more than 0.30%, the recrystallization temperature is raised and the manufacturing cost is only increased. It is preferably 0.1% or less.

【００１０】Ａｌは脱酸材として鋼の清浄化に必要であ
るとともに、本発明鋼においては、Ｃｒと同様耐錆性を
確保するために欠かせぬ元素で、ＣｒとＡｌの共存によ
り、耐錆性を著しく高める。この作用を得るには酸可溶
Ａｌにて０．０２％以上必要である。一方、その含有量
が０．１５％を超えると耐錆性の助長効果は飽和する。
加えて、０．１５％を超えた添加は介在物の生成を多く
するだけである。耐食性に関する好ましい共存効果は
０．０３０〜０．１００％で得られる。Al is necessary as a deoxidizing agent for cleaning steel, and in the steel of the present invention, like Cr, it is an essential element for ensuring rust resistance. Due to the coexistence of Cr and Al, Al Remarkably enhances rust resistance. To obtain this effect, 0.02% or more of acid-soluble Al is necessary. On the other hand, if its content exceeds 0.15%, the effect of promoting rust resistance is saturated.
In addition, additions above 0.15% only increase the formation of inclusions. A preferable coexistence effect on the corrosion resistance is obtained at 0.030 to 0.100%.

【００１１】Ｃｒは本発明鋼の耐食性を確保するために
は５．５％以上が必要である。しかしＣｒ含有量が１０
％以上では経済上望ましくない。また前記酸可溶Ａｌと
の共存により耐食性が高められるので１０％未満とす
る。In order to ensure the corrosion resistance of the steel of the present invention, Cr needs to be 5.5% or more. However, the Cr content is 10
% Or more is economically undesirable. Further, the coexistence with the acid-soluble Al enhances the corrosion resistance, so the content is made less than 10%.

【００１２】更に必要に応じてＣｕとＮｉを含有させ
る。Ｃｕ及びＮｉの耐錆性助長効果はそれぞれ０．０１
％未満では認められず、０．５０％を超えると鋼を脆化
し、加工性を劣化する。Further, Cu and Ni are contained if necessary. The rust resistance promoting effects of Cu and Ni are each 0.01
If it is less than 0.5%, it is not recognized, and if it exceeds 0.50%, the steel becomes brittle and the workability deteriorates.

【００１３】この鋼を用いれば、耐食性に優れているた
め、現在鋼板に施されている錫メッキ、クロムメッキ等
の表面処理を省略することも可能となる。Since this steel is excellent in corrosion resistance, it is possible to omit the surface treatment such as tin plating and chrome plating currently applied to steel sheets.

【００１４】次に加工方法について説明する。易開缶蓋
は概要図１の（ａ）フルオープン方式、（ｂ）ステイオ
ンタブ方式に示すように、缶本体１に開口片部２を形成
する切断案内溝３を設けている。図１のような易開缶蓋
はを成形するにあたり、従来技術である尖鋭刃の押圧方
法による図２のような切断案内溝の形成は、鋼板のＶ字
型の案内溝直下に歪みが集積するため、その部分に錆が
発生するため望ましくない。Next, the processing method will be described. The easy-open can lid is provided with a cutting guide groove 3 for forming an opening piece 2 in the can body 1 as shown in (a) Full open system and (b) Stein tab system of the outline. When forming the easy-open can lid as shown in FIG. 1, forming the cutting guide groove as shown in FIG. 2 by the pressing method of the sharp blade, which is a conventional technique, causes distortion to be accumulated just below the V-shaped guide groove of the steel plate. Therefore, rust is generated in that portion, which is not desirable.

【００１５】本発明は歪みの集積を起こさせることなく
易開缶性を保証する切断案内溝を形成するために、上下
金型の該肩半径部分にて、上述した鋼板を押圧加工成形
し、該肩半径で加工された部分に歪みの集積が起こらな
いようにした。図３に加工された鋼板の断面図を示す。According to the present invention, in order to form a cutting guide groove which guarantees easy opening without causing accumulation of strain, the above-mentioned steel plate is press-formed at the shoulder radius portions of the upper and lower molds, Accumulation of strain did not occur in the portion processed with the shoulder radius. FIG. 3 shows a cross-sectional view of the processed steel plate.

【００１６】開口片形状を構成する切断案内溝形成用上
下金型の肩半径を０．１mm〜１．０mmとした理由につい
て述べる。肩半径が０．１mmより小さい場合には肩半径
で加工された部分にやはり歪みが集積し、錆が発生する
ので望ましくない。肩半径が１．０mmより大きい場合に
は、肩半径で加工された切断溝があまりに緩やかなＲと
なってしまうので、開缶時に応力集中が起こりにくくな
り、缶蓋の開缶性が悪くなるので１．０mm以下とした。The reason why the upper and lower dies for forming the cutting guide groove forming the shape of the opening piece have a shoulder radius of 0.1 mm to 1.0 mm will be described. If the shoulder radius is smaller than 0.1 mm, distortion is still accumulated in the portion machined with the shoulder radius and rust occurs, which is not desirable. If the shoulder radius is greater than 1.0 mm, the cutting groove processed with the shoulder radius will have an excessively gentle radius R, so stress concentration will not occur easily during can opening, and the can openability of the can lid will deteriorate. Therefore, it is set to 1.0 mm or less.

【００１７】次にパンチとダイスのクリアランスを−
１．６mm〜０．３mmに限定した理由を示す。すなわち、
−１．６mm未満では、圧縮応力が大きくなりすぎ、０．
３mm以上では、クリアランスが大きすぎて圧縮による板
厚み減少ができず、引張りによって破断を生じる。Next, the clearance between the punch and the die-
The reason why it is limited to 1.6 mm to 0.3 mm is shown. That is,
If it is less than -1.6 mm, the compressive stress becomes too large, and
If it is 3 mm or more, the clearance is too large to reduce the plate thickness due to compression, and the tensile strength causes fracture.

【００１８】加工の際、開口片周縁部は、望みの厚みに
達するように上下金型の間にて押圧され、なだらかに板
厚変化した薄肉部を形成することとなる。最薄部金属厚
みは、開缶性の面から加工厚みの１／２以下、望ましく
は１／３以下とする必要がある。At the time of processing, the peripheral edge portion of the opening piece is pressed between the upper and lower molds so as to reach a desired thickness, thereby forming a thin-walled portion with a gradual plate thickness change. The metal thickness of the thinnest part needs to be ½ or less, preferably ⅓ or less of the processed thickness in terms of can openability.

【００１９】この加工により開缶時の破断位置は確定さ
れるが、開缶性の向上及び開缶後の開口片の形状を望ま
しいものとするため、上方あるいは下方に押し出された
開口片部を以前のレベルに近いところまで押し戻した加
工を行うことが可能である。押し戻された形状を図４に
示す。Although the breaking position at the time of opening the can is determined by this processing, in order to improve the can openability and to make the shape of the opening piece after opening the can desirable, the opening piece portion extruded upward or downward is formed. It is possible to perform processing that pushes back to a level close to the previous level. The pushed back shape is shown in FIG.

【００２０】この切断案内溝の深さあるいは最薄部板厚
等は、加工条件を所要に設定することにより、材料の加
工性に応じた所要の値とすることが可能であり、上述し
た鋼の加工性に応じて加工条件が選定される。The depth of the cutting guide groove, the thickness of the thinnest portion, or the like can be set to a required value according to the workability of the material by setting the working conditions as required. The processing conditions are selected according to the workability of.

【００２１】また、本発明の方法によれば、互いに凸の
滑らかな局面を有する肩半径部分による押し出しあるい
は押し戻し等のプレス加工を基本とした加工であるた
め、尖鋭刃の押圧方式に見られる工具寿命の問題は軽減
され、優れた生産性が保証される。Further, according to the method of the present invention, since the basic work is press work such as extrusion or push-back by the shoulder radius portions having mutually convex smooth surfaces, the tool found in the sharp blade pressing method is used. Life issues are reduced and excellent productivity is guaranteed.

【００２２】本発明は開口片の周辺部に存在する切断案
内溝の最適化を主な特徴とするものであり、取っ手と開
口片を缶本体から引きちぎり分離されるティアオフ方式
と、取っ手及び開口片ともに開缶後も缶本体に固着され
たまま残るステイオンタブ方式の両方式に適用すること
が可能である。The present invention is mainly characterized by optimizing the cutting guide groove existing in the peripheral portion of the opening piece. The tear-off system in which the handle and the opening piece are torn off from the main body of the can, and the handle and the opening. It is possible to apply both types of Steion tab method in which both pieces remain fixed to the body of the can after opening the can.

【００２３】[0023]

【実施例】以下に実施例について述べる。表１記載の成
分を有する鋼を真空溶解炉で溶製し、鋼塊とした。これ
らの鋼塊を１１５０℃×１hr均熱後、板厚３０mmに粗圧
延し、再び１１５０℃×１hr加熱後、板厚３．０mmに熱
延した。これらの熱延板を酸洗した後０．２mmに冷延
し、焼鈍を行った。焼鈍の条件は７５％Ｈ₂ ＋２５％Ｎ
₂ （露点−５０℃）の還元雰囲気の中に焼鈍温度７５０
℃で６０秒間保定し室温まで炉中冷却した。こうして作
製した鋼板で実験室にて蓋径６６mmのステイオンタブ方
式の蓋を成形し、耐食試験と開缶試験を行った。その結
果を表２に示す。試験No．１，２，３，４，５は本発明
であり、試験No．６，７，８，９，１０，１１，１２は
比較例である。EXAMPLES Examples will be described below. Steel having the components shown in Table 1 was melted in a vacuum melting furnace to obtain a steel ingot. These steel ingots were soaked at 1150 ° C. for 1 hr, roughly rolled to a plate thickness of 30 mm, heated again at 1150 ° C. for 1 hr, and hot-rolled to a plate thickness of 3.0 mm. These hot-rolled sheets were pickled, cold-rolled to 0.2 mm, and annealed. Annealing conditions are 75% H ₂ + 25% N
₂ (dew point -50 ° C) in a reducing atmosphere at an annealing temperature of 750
The temperature was held at 60 ° C. for 60 seconds and cooled in the furnace to room temperature. In the laboratory, a steel ion tab type lid having a lid diameter of 66 mm was formed from the thus-prepared steel sheet, and a corrosion resistance test and a can opening test were performed. The results are shown in Table 2. Test No. Test Nos. 1, 2, 3, 4, and 5 are the present invention. 6,7,8,9,10,11,12 are comparative examples.

【００２４】耐食性は３５℃に保存した大気中に３ケ月
放置した後の切断案内溝の錆の発生状況を目視観察し、
切断案内溝に全く錆の発生していないものを合格、少し
でも錆の発生が見られるものは不合格とした。開缶性
は、開缶した時の開缶力を測定し、初期破断時の開缶力
（ＰＯＰ）とその後の最大開缶力（Ｔｅａｒ）を測定
し、それらの荷重が現在市販されているアルミのステイ
オンタブ方式の蓋以下のものを合格とした。具体的には
ＰＯＰが２．０kgｆ以下でＴｅａｒが２．４kgｆを合格
とした。開口片が全部開口せず、切断されない切断案内
溝が一部残ったものや全部開口しても開口時の荷重が上
述した荷重を満足できないものは不合格とした。Corrosion resistance was visually observed by observing the rust generation state of the cutting guide groove after leaving it in the atmosphere stored at 35 ° C. for 3 months.
Those with no rust at all in the cutting guide groove were accepted, and those with a slight amount of rust were rejected. As for the can openability, the can open force when the can is opened is measured, the can open force (POP) at the time of initial rupture and the maximum can open force (Tear) after that are measured, and those loads are currently on the market. Aluminum Steion-tab type lids and below were accepted. Specifically, POP was 2.0 kgf or less and Tear was 2.4 kgf. Those in which all the opening pieces did not open and some cutting guide grooves which were not cut remained, or those in which the load at the time of opening could not satisfy the above-mentioned load even if all were opened were rejected.

【００２５】試験の結果を表２に記す。本発明の１〜５
は、切断案内溝に錆が全く発生せず、非常によい耐食性
を有し、現在鋼板に施されている錫メッキ、クロムメッ
キ等の表面処理を省略しても切断案内溝に塗料を補修す
るを必要がない。また蓋としてよい開缶性を有してい
る。本発明外の６〜１０は耐食性または開缶性が不合格
となっている。The test results are shown in Table 2. 1 to 5 of the present invention
Has no rust in the cutting guide groove, has very good corrosion resistance, and repairs the paint in the cutting guide groove even if the surface treatment such as tin plating and chrome plating currently applied to steel plates is omitted. You don't need Also, it has a good can openability as a lid. Nos. 6 to 10 other than the present invention failed in corrosion resistance or can openability.

【００２６】[0026]

【表１】 [Table 1]

【００２７】[0027]

【表２】 [Table 2]

【００２８】[0028]

【発明の効果】本発明により、スチール鋼板の缶易開缶
性蓋が実用化されれば、易開缶性蓋及び胴ともにスチー
ルのモノメタル缶が可能となり、近年の地球環境問題に
対応するリサイクルに適した商品を市場に提供すること
が可能である。Industrial Applicability According to the present invention, if a can easily openable lid made of steel plate is put into practical use, it becomes possible to make a steel monometal can for both the easily openable lid and the body, which will cope with recent global environmental problems. It is possible to provide the market with products suitable for recycling.

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

【図１】易開缶蓋を示す図であり、（ａ）はフルオープ
ン方式、（ｂ）はステイオンタブ方式を示す。1A and 1B are diagrams showing an easy-open can lid, in which FIG. 1A shows a full open system, and FIG.

【図２】従来技術による切断案内溝の断面を示す図であ
る。FIG. 2 is a view showing a cross section of a cutting guide groove according to a conventional technique.

【図３】本発明による易開缶性蓋の切断案内溝の断面図
である。FIG. 3 is a cross-sectional view of a cutting guide groove of the easy-open can lid according to the present invention.

【図４】押し戻し加工を行った本発明の切断案内溝の断
面図である。FIG. 4 is a cross-sectional view of a cutting guide groove of the present invention that has been subjected to pushback processing.

【符号の説明】 １ 缶本体 ２ 開口片部 ３ 切断案内溝[Explanation of symbols] 1 can body 2 opening piece 3 cutting guide groove

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 重量％として、 Ｃ ：０．０２％以下、 Ｓｉ：０．３％以下、 Ｍｎ：０．５％以下、 Ｐ ：０．０２５％以下、 Ｓ ：０．０２５％以下、 酸可溶Ａｌ：０．０２〜０．１５％、 Ｔｉ：Ｃ量の４倍以上かつ０．０２％以上で０．３０％
以下、 Ｃｒ：５．５〜１０％ を含有し、残部鉄及び不可避的不純物からなる鋼板を開
口片形状を構成する切断案内溝形成用金型の肩半径が、
０．１mm〜１．０mmでかつクリアランスを−０．６mm〜
１．６mmとした金型を用い、上下金型の該肩半径にて、
押圧加工成形し、加工最薄部の金属厚みを加工前の金属
厚みの１／２以下に薄くした切断案内溝を形成すること
を特徴とする易開缶性蓋の製造方法。1. As weight%, C: 0.02% or less, Si: 0.3% or less, Mn: 0.5% or less, P: 0.025% or less, S: 0.025% or less, acid Soluble Al: 0.02 to 0.15%, Ti: C content of 4 times or more and 0.02% or more, 0.30%
Hereinafter, the shoulder radius of the die for forming the cutting guide groove, which forms the opening piece shape of the steel plate containing Cr: 5.5 to 10% and the balance of iron and unavoidable impurities,
0.1mm ~ 1.0mm and clearance -0.6mm ~
Using a 1.6 mm die, with the shoulder radii of the upper and lower dies,
A method for manufacturing an easily openable lid, which comprises press-forming and forming a cutting guide groove in which a metal thickness of a thinnest portion to be processed is reduced to ½ or less of a metal thickness before processing. 【請求項２】 鋼成分として、更に Ｃｕ：０．０１〜０．５０％、 Ｎｉ：０．０１〜０．５０％ の少なくとも１種を含有させることを特徴とする請求項
１記載の易開缶性蓋の製造方法。2. The easy-to-open composition according to claim 1, further comprising at least one of Cu: 0.01 to 0.50% and Ni: 0.01 to 0.50% as a steel component. Method for manufacturing can lid.