JPH1129897A - Electrolytic chromic acid-treated steel sheet being excellent in plating adhesion and corrosion resistance and weldable without grinding - Google Patents
Electrolytic chromic acid-treated steel sheet being excellent in plating adhesion and corrosion resistance and weldable without grindingInfo
- Publication number
- JPH1129897A JPH1129897A JP10133056A JP13305698A JPH1129897A JP H1129897 A JPH1129897 A JP H1129897A JP 10133056 A JP10133056 A JP 10133056A JP 13305698 A JP13305698 A JP 13305698A JP H1129897 A JPH1129897 A JP H1129897A
- Authority
- JP
- Japan
- Prior art keywords
- steel sheet
- plating
- adhesion
- amount
- corrosion resistance
- 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.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
- C23C28/023—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
- C23C10/60—After-treatment
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
- C25D11/38—Chromatising
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/10—Electroplating with more than one layer of the same or of different metals
- C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/627—Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrochemistry (AREA)
- Mechanical Engineering (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】この発明は、ガロン缶やペー
ル缶等の3ピース溶接缶胴として使用する電解クロム酸
処理鋼板、とりわけ研削処理による皮膜の除去を行うこ
となく溶接に供する電解クロム酸処理鋼板に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic chromic acid-treated steel sheet used as a three-piece welded can body such as a gallon can or a pail, and more particularly to an electrolytic chromic acid treated for welding without removing a film by grinding. It relates to a steel plate.
【0002】[0002]
【従来の技術】ガロン缶やペール缶等の缶胴には、ぶり
きや電解クロム酸処理鋼板等が使用されている。中でも
ぶりきは、Snめっきが厚いために耐食性および溶接性に
優れる反面、Snの使用量が多いために高価であり、しか
も省資源の観点からも好ましくない。2. Description of the Related Art Tin bodies and electrolytic chromic acid-treated steel sheets are used for can bodies such as gallon cans and pail cans. Above all, tinplate is excellent in corrosion resistance and weldability due to thick Sn plating, but expensive due to the large amount of Sn used, and is not preferable from the viewpoint of resource saving.
【0003】一方、電解クロム酸処理鋼板は、Snを使用
しないために、低コストでかつ塗料密着性に優れる反
面、鋼板の皮膜表面の非金属Cr層(Cr水和酸化物層)が
非導電性物質であることから、そのまま溶接することが
困難であり、事前に溶接部の表面を研削する必要があ
る。この研削処理において発生する研削粉は、作業環境
を悪化するほか、溶接後の缶に付着するため、特に食品
用途の缶で問題視される。そこで、かような問題を解決
するために、電解クロム酸処理鋼板の溶接性を向上し、
無研削での溶接を実現するための様々な試みが行われて
きた。On the other hand, electrolytic chromic acid-treated steel sheets are low in cost and have excellent paint adhesion because they do not use Sn, but the nonmetallic Cr layer (Cr hydrated oxide layer) on the coating surface of the steel sheet is nonconductive. It is difficult to perform welding as it is because it is a volatile substance, and it is necessary to grind the surface of the weld in advance. The grinding powder generated in the grinding process deteriorates the working environment and adheres to the can after welding, so that it is regarded as a problem particularly in a can for food use. Therefore, in order to solve such a problem, the weldability of the electrolytic chromic acid-treated steel sheet was improved,
Various attempts have been made to realize welding without grinding.
【0004】例えば、特公平3−69999 号公報では、鋼
板表面に、40〜150mg/m2の金属Cr層および金属Cr換算で
5〜25mg/m2 の非金属Cr層からなりかつ金属Crの一部が
突起している皮膜を形成することが、提案されている。
この提案によって、確かに溶接性は向上するが、金属Cr
の一部を突起させたために、金属Cr層の薄い部分が局部
的に生じて耐食性が劣化することが問題として残る。[0004] For example, in Kokoku 3-69999 discloses, on the surface of the steel sheet, in 40~150mg / m 2 of metallic Cr layer and the metal Cr terms become non-metallic Cr layer of 5 to 25 mg / m 2 and the metal Cr It has been proposed to form a partially projecting coating.
This proposal certainly improves the weldability, but the metal Cr
However, a problem remains that a thin portion of the metal Cr layer is locally formed and the corrosion resistance is deteriorated due to the projection of a part of the metal Cr layer.
【0005】また、特公平5−27720 号公報では、鋼板
表面に、45〜90mg/m2 の平滑に析出させた金属Cr層と、
Crとして1〜10mg/m2 の難溶性のCr水和酸化物層とを形
成することが提案されている。しかしながら、溶接性は
不十分であり、しかもCr水和酸化物層の厚みを従来対比
で減少させたために、耐食性が劣化することも問題とな
る。In Japanese Patent Publication No. Hei 5-27720, a metal Cr layer of 45 to 90 mg / m 2 is deposited on a steel sheet surface.
It has been proposed to form a hardly soluble Cr hydrated oxide layer of 1 to 10 mg / m 2 as Cr. However, the weldability is insufficient, and the corrosion resistance is deteriorated because the thickness of the Cr hydrated oxide layer is reduced compared to the conventional one.
【0006】従って、耐食性を損なうことなく、電解ク
ロム酸処理鋼板の溶接性を改善するためには、やはり鋼
板表面に微量でもSnを有することが必要であることか
ら、特公平2-16397 号公報では、鋼板表面に50〜900mg/
m2のSnめっきを有し、その上に7〜100mg/m2の金属Cr層
およびCr換算で5〜50mg/m2 のCr水和酸化物層を有し、
さらにSnめっきによって被覆されない、円換算で直径0.
5 〜20μmの鋼板露出部が存在する鋼板が、提案されて
いる。Accordingly, in order to improve the weldability of the electrolytic chromic acid-treated steel sheet without deteriorating the corrosion resistance, it is necessary for the steel sheet surface to contain even a small amount of Sn. Then, 50 ~ 900mg /
has a Sn plating m 2, has a Cr hydrous oxide layer of 5 to 50 mg / m 2 on at 7~100mg / m 2 of the metal Cr layer and Cr in terms of its,
In addition, it is not covered with Sn plating and has a diameter of 0 in circle.
A steel plate having a steel plate exposed portion of 5 to 20 μm has been proposed.
【0007】ここでは、Snめっき後にSnを加熱溶融、い
わゆるリフローしてもしなくても良いとされているが、
Snめっき後にリフローを行うと、もともとSn量が少ない
上に、リフロー時にSnと素地鋼との合金化が進むことで
金属Sn量が減少してしまう。しかも、通常は溶接の前に
塗装焼き付けを行うため、その際の熱処理によって金属
Sn量はさらに減少する。その結果、溶接性は不十分なも
のとなる。Here, it is stated that Sn is not required to be heated and melted after Sn plating, that is, so-called reflow is required.
If reflow is performed after Sn plating, the amount of Sn is originally small, and the amount of metallic Sn is reduced due to the progress of alloying between Sn and the base steel during reflow. Moreover, since paint baking is usually performed before welding, metal treatment is performed by heat treatment at that time.
The amount of Sn further decreases. As a result, the weldability becomes insufficient.
【0008】一方、Snめっき後にリフローしない場合
は、確かに溶接性の改善効果があるものの、Snめっきと
素地鋼との間の密着性が著しく低下することが問題とな
る。ここで、鋼板上に直接電解クロム酸処理が行われる
場合、析出する金属Cr層と素地鋼板との界面の密着性は
一般に良好である。これは、FeとCrの構造が両者とも体
心立方晶であり、かつ格子定数も近くて類似した構造で
あることから、Crめっき膜が鋼板上にエピタキシャルに
成長し、結晶学的に界面の整合性が良いためであると考
えられる。これに対して、SnとFeの構造は全く異なるた
め、鋼板とSnめっきとの界面での密着性は一般に悪い。
なお、Snめっき後にリフローした場合は、リフロー処理
によってSnと素地鋼との間にSn−Fe合金相を形成するこ
とで密着性は向上するが、既に述べたようにリフローす
ると溶接性が不十分になることが問題になる。On the other hand, when reflow is not performed after Sn plating, although there is an effect of improving weldability, the problem is that the adhesion between Sn plating and the base steel is significantly reduced. Here, when the electrolytic chromic acid treatment is performed directly on the steel sheet, the adhesion at the interface between the precipitated metal Cr layer and the base steel sheet is generally good. This is because the structures of Fe and Cr are both body-centered cubic and similar in structure with similar lattice constants.Therefore, the Cr plating film grows epitaxially on the steel sheet, and the crystallographic interface This is considered to be due to good consistency. On the other hand, since the structures of Sn and Fe are completely different, the adhesion at the interface between the steel sheet and the Sn plating is generally poor.
In the case of reflow after Sn plating, adhesion is improved by forming a Sn-Fe alloy phase between Sn and the base steel by reflow treatment, but as described above, weldability is insufficient when reflow is performed. Becomes a problem.
【0009】さらに、特公平6-96790 号公報では、鋼板
表面に径が0.2 〜2.0 μmおよび高さ0.1 μm以上のSn
粒からなる、20〜200mg/m2のSn層を有し、その上に30〜
150mg/m2の金属Cr層およびCr換算で2〜40mg/m2 のCr水
和酸化物層を有する鋼板が提案されている。この提案に
よれば、確かに溶接性改善の点では一定の効果が得られ
るが、この場合もSnめっきの密着性が悪いという問題は
依然として解決されていない。Furthermore, Japanese Patent Publication No. 6-96790 discloses that a steel sheet having a diameter of 0.2 to 2.0 μm and a height of 0.1 μm or more is coated on a steel sheet surface.
Made from the grain has a Sn layer of 20 to 200 mg / m 2,. 30 to thereon
A steel sheet having a 150 mg / m 2 metal Cr layer and a Cr hydrated oxide layer of 2 to 40 mg / m 2 in terms of Cr has been proposed. According to this proposal, although a certain effect can be obtained in terms of improving the weldability, the problem that the adhesion of the Sn plating is poor still remains in this case.
【0010】[0010]
【発明が解決しようとする課題】この発明は、Snめっき
を形成して耐食性を損なうことなく溶接性を向上した電
解クロム酸処理鋼板において、Snめっきの密着性を改善
しようとするものである。SUMMARY OF THE INVENTION The present invention seeks to improve the adhesion of Sn plating in an electrolytic chromic acid-treated steel sheet which has improved weldability without forming Sn plating and impairing corrosion resistance.
【0011】[0011]
【課題を解決するための手段】この発明は、鋼板の少な
くとも片面に、表面のNi濃度が1wt%以上20wt%未満の
Ni拡散層および、該Ni拡散層上にリフローすることなく
形成した、鋼板片面当たりの付着量が20〜500mg/m2のSn
めっきを有し、さらに鋼板両面の最外層を、鋼板片面当
たりの付着量が30〜200mg/m2の金属Cr層および同付着量
がCr換算で4〜18mg/m2 のCr水和酸化物層による表面被
膜で覆って成ることを特徴とするめっき密着性および耐
食性に優れた無研削での溶接が可能な電解クロム酸処理
鋼板である。According to the present invention, at least one surface of a steel sheet has a surface Ni concentration of 1 wt% or more and less than 20 wt%.
Ni diffusion layer and was formed without reflowing on the Ni diffusion layer, the amount of deposition per steel sheet one side of 20 to 500 mg / m 2 Sn
It has a plating, further the outermost layer of the steel sheet both sides, coating weight of 30 to 200 mg / m 2 of the metal Cr layer and the coating weight of Cr hydrous oxide of 4~18mg / m 2 of Cr in terms of per steel sided An electrolytic chromic acid-treated steel sheet which is excellent in plating adhesion and corrosion resistance and which can be welded without grinding, characterized by being covered with a surface coating of a layer.
【0012】ここで、Snめっきの付着量が50〜300mg/m2
および金属Cr層の付着量が30〜120mg/m2であることが、
とりわけ缶の内外面ともに塗装して使用しかつ缶内容物
として食品を充填する場合に適している。同様に、Snめ
っきの付着量が20〜200mg/m2および金属Cr層の付着量が
80〜200mg/m2であることが、とりわけ缶の内側面は無塗
装で使用しかつ内容物としてアルカリ性の剥離剤等を充
填する場合に適している。そして、Snめっきの付着量が
300 〜500mg/m2および金属Cr層の付着量が100〜200mg/m
2であることが、とりわけ缶の内側面は主として無塗装
で使用し、かつ内容物として有機溶剤等を充填する場合
に適している。Here, the Sn plating adhesion amount is 50 to 300 mg / m 2.
And the amount of deposition of the metal Cr layer to be 30~120mg / m 2,
In particular, it is suitable when both the inner and outer surfaces of the can are painted and used and food is filled as the contents of the can. Similarly, the adhesion amount of Sn plating adhesion amount of 20 to 200 mg / m 2 and the metal Cr layer
The content of 80 to 200 mg / m 2 is particularly suitable when the inner surface of the can is used without painting and is filled with an alkaline release agent or the like as the content. And the adhesion amount of Sn plating is
300 adhesion amount to 500 mg / m 2 and the metal Cr layer is 100 to 200 mg / m
A value of 2 is particularly suitable when the inner surface of the can is mainly used without painting and is filled with an organic solvent or the like as the content.
【0013】[0013]
【発明の実施の形態】さて、この発明においては、まず
電解クロム酸処理鋼板の特徴である、優れた塗料密着性
を確保するために、無水クロム酸を主体とする水溶液中
での陰極電解により、金属Cr層およびCr水和酸化物層か
らなる表面皮膜(以下、電解クロム酸処理皮膜と称す
る)を、鋼板両面の最外層として形成する必要がある。BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, first, in order to secure excellent paint adhesion characteristic of electrolytic chromic acid-treated steel sheet, cathodic electrolysis in an aqueous solution mainly composed of chromic anhydride is carried out. It is necessary to form a surface film composed of a metal Cr layer and a Cr hydrated oxide layer (hereinafter referred to as electrolytic chromic acid-treated film) as the outermost layers on both surfaces of the steel sheet.
【0014】次に、電解クロム酸処理皮膜の下層には、
溶接性を確保するのに必要な量のSnを、少なくとも鋼板
の片面に有する必要がある。なお、Snめっきの析出形態
は特に限定されず、連続であっても、またミクロ的に見
て不連続であっても構わないし、粒状あるいは隆起状の
析出形態であっても構わない。ただし、このSnめっき
は、Snの融点直上まで加熱溶融させる、つまりリフロー
することなく設けることが肝要である。なぜなら、この
発明では、Snめっきの量を溶接性が確保される必要最低
限度に抑えているのに対して、リフローを行うと0.3 〜
0.5g/m2 程度のSnが素地鋼との合金化によって失われる
のが通例であるから、リフローによるSnの消失は避けな
ければならない。Next, under the electrolytic chromic acid treatment film,
It is necessary that at least one side of the steel sheet has an amount of Sn necessary for securing the weldability. The precipitation form of the Sn plating is not particularly limited, and may be continuous, discontinuous when viewed microscopically, or may be a granular or raised precipitation form. However, it is important that the Sn plating be heated and melted to just above the melting point of Sn, that is, provided without reflow. The reason is that, in the present invention, the amount of Sn plating is suppressed to the minimum necessary for ensuring the weldability, whereas when reflow is performed, 0.3 to
Since about 0.5 g / m 2 of Sn is usually lost by alloying with the base steel, the loss of Sn due to reflow must be avoided.
【0015】しかしながら、Snめっき後のリフローを省
略するとSnめっきと鋼板との密着性が悪くなることは、
前述のとおりである。この点を改善する方途について発
明者等は種々の検討を行ったところ、Snめっきの下地と
して鋼板表面にNi拡散層を予め形成することによって、
Snめっきとその下地との間の密着性が著しく改善される
ことが新たに判明したのである。この理由は定かではな
いが、SnとNiとは室温でも相互拡散して合金相を形成す
ることから、鋼板表面にNi拡散層を設けることで、室温
で放置しておいても、鋼中のNiとSnとの界面に微量の合
金相が生成し、これにより密着性が改善されるのではな
いかと推定される。However, if the reflow after the Sn plating is omitted, the adhesion between the Sn plating and the steel sheet deteriorates.
As described above. The inventors conducted various studies on ways to improve this point.By forming a Ni diffusion layer in advance on the steel sheet surface as a base for Sn plating,
It was newly found that the adhesion between the Sn plating and the base was significantly improved. The reason for this is not clear, but Sn and Ni interdiffuse at room temperature to form an alloy phase, so by providing a Ni diffusion layer on the surface of the steel sheet, It is presumed that a small amount of alloy phase is formed at the interface between Ni and Sn, and this may improve the adhesion.
【0016】ここで、Ni拡散層の表面におけるNi濃度を
20wt%未満に規制することが肝要である。なぜなら、Ni
濃度が20wt%以上になると、耐食性が急激に劣化するか
らである。すなわち、Fe−Ni2元系状態図(Binary Allo
y Phase Diagrams Second Edition, ASM Internationa
l) によれば、200 ℃以下の熱平衡状態において、Fe−2
0wt%Ni合金はα-Fe 中へのNiの固溶体と金属間化合物F
eNi3 に2相分離している。従って、Ni濃度が高くなる
と、異相であるところのFeNi3 による鋼板表面での占有
面積が増大し、腐食環境に曝された際にFeNi3 相が局部
カソードとなりアノードとなる鋼板との間のガルバニッ
ク電流が増大することにより、耐食性が劣化するのでは
ないかと推定される。Here, the Ni concentration on the surface of the Ni diffusion layer is
It is important to regulate to less than 20 wt%. Because Ni
This is because when the concentration exceeds 20 wt%, the corrosion resistance rapidly deteriorates. That is, the Fe-Ni binary system phase diagram (Binary Allo
y Phase Diagrams Second Edition, ASM Internationala
According to l), in thermal equilibrium below 200 ° C, Fe-2
0wt% Ni alloy is a solid solution of Ni in α-Fe and intermetallic compound F
eNi 3 separated into two phases. Therefore, when the Ni concentration increases, the occupied area on the steel sheet surface by FeNi 3 which is a different phase increases, and when exposed to a corrosive environment, the FeNi 3 phase becomes a local cathode and becomes galvanic between the steel sheet serving as the anode. It is presumed that corrosion resistance deteriorates due to the increase in current.
【0017】また、Ni拡散層の表面でのNi濃度が1wt%
未満であると、Snとの界面で生じる合金相の形成が不十
分になって優れた密着性が得られないため、Ni拡散層の
表面でのNi濃度は1wt%以上、好ましくは3wt%以上は
必要になる。なお、Ni拡散層の表面とは、Ni拡散処理直
後に、オージェ電子分光法を用いて測定される程度の深
さ、すなわち数nmの領域を対象とする。そして、該領域
でのNi濃度は、鋼板表面から内部へオージェ電子分光法
による測定を行った際に得られる、深さ方向プロファイ
ルの典型例を図1に示すように、当該プロファイルにお
いて、SnとFeとの界面に現れるNiのピークa1 からa3
までの強度の積算値Aと、NiとFeとが共存するa2 から
a3 までのFe強度の積算値Bを、重量に換算したA/
(A+B)として定義される。The Ni concentration on the surface of the Ni diffusion layer is 1 wt%.
If it is less than 3, the formation of an alloy phase at the interface with Sn becomes insufficient and excellent adhesion cannot be obtained. Therefore, the Ni concentration on the surface of the Ni diffusion layer is 1 wt% or more, preferably 3 wt% or more. Is needed. It should be noted that the surface of the Ni diffusion layer is intended to have a depth that can be measured by Auger electron spectroscopy immediately after the Ni diffusion treatment, that is, a region of several nm. Then, as shown in FIG. 1, a typical example of a depth direction profile obtained when the Ni concentration in the region is measured by Auger electron spectroscopy from the surface of the steel sheet to the inside thereof is Sn and Sn in the profile. from the peak a 1 of Ni appearing at the interface between the Fe a 3
The integrated value A of the intensity up to and the integrated value B of the Fe intensity from a 2 to a 3 where Ni and Fe coexist are converted into a weight A /
Defined as (A + B).
【0018】なお、このNi拡散層は、鋼板にNiめっきを
施したのち、例えば連続焼鈍などの熱処理を行って形成
する。ここで、熱処理前に行われるNiめっきは、5mg/m
2 未満では密着性の改善効果が得られないため、5mg/m
2 以上にすることが好ましい。また、Niめっき量の上限
は、上述のように、熱処理後の表面Ni濃度が20wt%未満
になるように、熱処理条件との兼ね合いで決定されるべ
きであるが、連続焼鈍前に行われるNiめっき量が500mg/
m2をこえるとSnとNiとの合金相が多くなり、この相自体
の凝集破壊によって素地鋼とSnめっきとの密着性を確保
できなくなるため、500mg/m2以下とすることが好まし
い。The Ni diffusion layer is formed by subjecting a steel plate to Ni plating and then performing a heat treatment such as continuous annealing. Here, Ni plating performed before heat treatment is 5 mg / m
If it is less than 2 , the effect of improving the adhesion cannot be obtained, so that 5 mg / m
It is preferable to set it to 2 or more. The upper limit of the amount of Ni plating should be determined in consideration of the heat treatment conditions so that the surface Ni concentration after the heat treatment is less than 20 wt% as described above. Plating amount 500mg /
If m 2 is exceeded, the alloy phase of Sn and Ni increases, and the cohesive failure of this phase itself makes it impossible to secure the adhesion between the base steel and the Sn plating. Therefore, the content is preferably 500 mg / m 2 or less.
【0019】さらに、熱処理条件としては、一般的な連
続焼鈍条件で良く、特に限定する必要はなく、鋼板素材
そのものの鋼種や、要求される機械的特性により決定す
ればよい。次いで、熱処理後に、Ni拡散層表面のNi濃度
が規定の値になるように、Niめっき量を決定することが
望ましい。ちなみに、鋼種が低炭素鋼の場合には、680
〜700 ℃で10〜100 秒程度の熱処理を、また鋼種が極低
炭素鋼の場合には、760 ℃で10〜100 秒程度の熱処理
を、行うことが普通である。Furthermore, the heat treatment conditions may be general continuous annealing conditions, and need not be particularly limited, and may be determined according to the steel type of the steel sheet material itself and the required mechanical properties. Next, after the heat treatment, the amount of Ni plating is desirably determined so that the Ni concentration on the surface of the Ni diffusion layer becomes a specified value. By the way, when the steel type is low carbon steel, 680
Usually, heat treatment is performed at about 700 ° C. for about 10 to 100 seconds, and when the steel type is extremely low carbon steel, heat treatment is performed at 760 ° C. for about 10 to 100 seconds.
【0020】なお、この発明におけるNi拡散層と類似し
た機能を有する皮膜として、Fe−Ni合金めっきあるいは
極微量のNiめっきも考えられるが、発明者らの検討によ
れば、鋼板表面にFe−Ni合金めっきや極微量Niめっきの
皮膜を設けた場合は、Niめっき後に熱拡散処理を行った
場合と異なり、密着性の改善効果が得られず、また耐食
性にも劣る結果となった。この理由は定かではないが、
以下のような相違によるものと推定される。As a film having a function similar to that of the Ni diffusion layer in the present invention, an Fe—Ni alloy plating or a trace amount of Ni plating may be considered. When a film of Ni alloy plating or a trace amount of Ni plating was provided, the effect of improving the adhesion was not obtained and the result was also inferior in corrosion resistance, unlike the case where thermal diffusion treatment was performed after Ni plating. I'm not sure why,
It is presumed to be due to the following differences.
【0021】すなわち、Fe−Ni合金めっきは電析により
得られる合金であり、しばしば熱平衡状態とは異なる相
構成になること、そして合金元素以外の不純物が共析す
るために、この発明に従って熱拡散処理により生成され
るNi拡散層中のNiとは、状態が異なると推定される。ま
た、極微量Niめっきは、そのめっき量を限りなく減らし
ていくことによって、表面分析にて同定される最表面Ni
濃度を、見掛け上は20wt%未満にすることが可能であ
る。しかしながら、その場合の表面NiはあくまでもNi相
として存在しているはずであり、この発明に従って熱拡
散処理により鋼板のα−Fe相中に固溶して存在するNiと
は、構造が異なると推定される。以上のような相違によ
り、鋼板表面にFe−Ni合金めっき皮膜、あるいは極微量
Niめっき皮膜を設けた場合には、Niめっき後に熱拡散処
理を行った場合と異なり、密着性改善効果は見られず、
また耐食性も劣るものと考えられる。That is, the Fe—Ni alloy plating is an alloy obtained by electrodeposition, and often has a phase constitution different from the thermal equilibrium state. It is presumed that the state is different from Ni in the Ni diffusion layer generated by the processing. In addition, the extremely small amount of Ni plating reduces the amount of plating as much as possible, so that the outermost Ni plating identified by surface analysis is
Concentrations can be apparently less than 20 wt%. However, in this case, the surface Ni should exist as a Ni phase to the last, and it is presumed that the structure is different from that of Ni present as a solid solution in the α-Fe phase of the steel sheet by the thermal diffusion treatment according to the present invention. Is done. Due to the above differences, Fe-Ni alloy plating film
When the Ni plating film is provided, unlike the case where the thermal diffusion treatment is performed after the Ni plating, the effect of improving the adhesion is not seen.
It is also considered that the corrosion resistance is poor.
【0022】この発明では、上記Ni拡散層上にSnめっき
を形成することは既に述べた通りであり、このSnめっき
は、その付着量を20〜500mg/m2の範囲とする。すなわ
ち、Snの付着量が20mg/m2 未満では溶接性が不十分にな
り、一方500mg/m2をこえると電解クロム酸処理鋼板とし
ての色調が得られない上、経済性も損なわれる。In the present invention, the formation of the Sn plating on the Ni diffusion layer is as described above, and the amount of the Sn plating is in the range of 20 to 500 mg / m 2 . That is, if the amount of Sn deposited is less than 20 mg / m 2 , the weldability becomes insufficient. On the other hand, if it exceeds 500 mg / m 2 , the color tone of the electrolytic chromic acid-treated steel sheet cannot be obtained and the economy is impaired.
【0023】さらに、鋼板両面の最外層に電解クロム酸
処理皮膜を設けることも上述の通りであり、この電解ク
ロム酸処理皮膜におけるCr水和酸化物層の付着量は、優
れた塗料密着性を得るために4mg/m2 〜18mg/m2 の範囲
とする。すなわち、付着量が4mg/m2 未満では塗料の密
着性が不十分であり、一方18mg/m2 をこえると密着性は
ほとんど変わらないものの外観が劣化するため、18mg/m
2 を上限とする。一方、電解クロム酸処理皮膜における
金属Cr層の付着量は、優れた塗装後の耐食性を得るため
に30mg/m2 〜200 mg/m2 の範囲とする。すなわち、30mg
/m2 未満では塗装後の耐食性が不十分であり、一方200m
g/m2をこえると塗装後の耐食性はほとんど変わらないが
外観が劣化するので、これを上限とする。Further, as described above, the outermost layer on both surfaces of the steel sheet is provided with an electrolytic chromic acid-treated film. the range of 4mg / m 2 ~18mg / m 2 to obtain. That is, if the adhesion amount is less than 4 mg / m 2 , the adhesion of the paint is insufficient, while if it exceeds 18 mg / m 2 , the adhesion is hardly changed but the appearance is deteriorated.
2 is the upper limit. On the other hand, the adhesion amount of the metal Cr layer in the electrolytic chromic acid-treated film is in the range of 30 mg / m 2 to 200 mg / m 2 in order to obtain excellent corrosion resistance after painting. That is, 30mg
/ m is less than 2 is insufficient corrosion resistance after painting, whereas 200m
If it exceeds g / m 2 , the corrosion resistance after coating hardly changes, but the appearance deteriorates.
【0024】上記の各皮膜を有する電解クロム酸処理鋼
板は、それを缶胴とした場合、缶の内外面ともに塗装ま
たは無塗装にて使用することができ、また缶内容物は食
品のほか、アルカリ性の剥離剤や有機溶剤などを充填す
ることができる。When the electrolytic chromic acid-treated steel sheet having each of the above-mentioned coatings is used as a can body, both the inner and outer surfaces of the can can be used with or without painting. An alkaline release agent or an organic solvent can be filled.
【0025】とりわけ、缶の内外面ともに塗装して使用
し、かつ缶内容物として食品を充填する場合には、Snめ
っきの付着量を50〜300mg/m2および金属Cr層の鋼板片面
当たりの付着量を30〜120mg/m2とした鋼板が有利に適合
する。すなわち、Snめっきの付着量が50mg/m2 未満では
溶接性が不十分であり、300mg/m2をこえると電解クロム
酸処理鋼板の特徴であるところの優れた塗料密着性が劣
化する。また、金属Cr層の付着量は、30mg/m2 未満にな
ると塗装後の耐食性が不十分になり、一方120mg/m2をこ
えると塗装後の耐食性はほとんど変わらないことから経
済性を考慮して120mg/m2以下とする。In particular, when both the inner and outer surfaces of the can are painted and used, and food is filled as the contents of the can, the amount of Sn plating adhered is 50 to 300 mg / m 2 and the metal Cr layer A steel sheet with a deposit of 30-120 mg / m 2 is advantageously suitable. That is, if the adhesion amount of Sn plating is less than 50 mg / m 2 , the weldability is insufficient, and if it exceeds 300 mg / m 2 , the excellent paint adhesion characteristic of the electrolytic chromic acid-treated steel sheet is deteriorated. Further, adhesion of the metal Cr layer is insufficient in corrosion resistance after painting to be less than 30 mg / m 2, whereas the corrosion resistance after coating and more than 120 mg / m 2 is considering economical efficiency since almost unchanged 120 mg / m 2 or less.
【0026】また、缶の内側面は無塗装で使用し、かつ
内容物としてアルカリ性の剥離剤等を充填する場合に
は、缶内側面に塗膜による防食効果が期待できないた
め、無塗装での耐食性が重要になる。例えばガロン缶等
は、開封されたのち長期に渡り使用されることもあるた
め、特に缶内面側のヘッドスペース部が厳しい腐食環境
に晒されることになる。従って、このような用途には、
Snめっきの付着量を20〜200mg/m2および金属Cr層の鋼板
片面当たりの付着量を80〜200mg/m2とした鋼板が有利に
適合する。すなわち、Snは両性金属であり、アルカリに
腐食されるため、アルカリ性の剥離剤等を内容物とする
場合は、極力その付着量を少なくする必要があるところ
から、上限を200mg/m2とした。しかしながら、Sn量が20
mg/m2 未満では溶接が困難になるため、20mg/m2 を下限
とする。また、このような缶内面側の腐食環境において
は、鋼板表面に形成されたNi拡散層による耐食性の向上
効果も大きい。また、金属Cr層の付着量は、80mg/m2 未
満になると耐食性が不十分になり、一方200mg/m2をこえ
ると耐食性はほとんど変わらないことから経済性を考慮
して200 g/m2以下とする。When the inner surface of the can is used without painting and is filled with an alkaline release agent or the like as the content, the anticorrosive effect of the coating film cannot be expected on the inner surface of the can. Corrosion resistance becomes important. For example, since a gallon can is used for a long time after being opened, the head space portion on the inner surface side of the can is particularly exposed to a severe corrosive environment. Therefore, for such applications,
A steel sheet having an Sn plating adhesion amount of 20 to 200 mg / m 2 and a metal Cr layer having an adhesion amount of 80 to 200 mg / m 2 per one side of the steel sheet is advantageously applied. That, Sn is an amphoteric metal, because it is corroded by the alkali, if the contents of such alkaline stripper was from where it is necessary to reduce the adhesion amount as much as possible, the upper limit is 200 mg / m 2 . However, when the amount of Sn is 20
If it is less than mg / m 2 , welding becomes difficult, so the lower limit is 20 mg / m 2 . Further, in such a corrosive environment on the inner surface side of the can, the effect of improving corrosion resistance by the Ni diffusion layer formed on the surface of the steel sheet is great. Further, adhesion of the metal Cr layer, 80 mg / m less than 2 when insufficient corrosion resistance, whereas 200 mg / m 2 to more than the corrosion resistance since it hardly changes and economic considerations 200 g / m 2 The following is assumed.
【0027】さらに、缶の内側面は主として無塗装で使
用し、かつ内容物として有機溶剤等を充填する場合に
は、缶内側面に塗膜による防食効果が期待できないた
め、無塗装での耐食性が重要になる。例えばガロン缶等
は、開封されたのち長期に渡り使用されることもあるた
め、特に缶内面側のヘッドスペース部が厳しい腐食環境
に晒されることになる。従って、このような用途には、
Snめっきの付着量を300 〜500mg/m2および金属Cr層の鋼
板片面当たりの付着量を100 〜200mg/m2とした鋼板が有
利に適合する。すなわち、Snめっきの付着量は、500mg/
m2をこえると外観が白化し、電解クロム酸処理鋼板とし
ての色調が得られなくなる上、Sn量の増加により経済性
も損なわれるため、500mg/m2を上限とする。一方、Sn量
の下限は、缶内面側の耐食性を確保するために300mg/m2
とする。また、金属Cr層の付着量は、100mg/m2未満にな
ると耐食性が不十分になり、一方200mg/m2をこえると耐
食性はほとんど変わらないことから経済性を考慮して20
0mg/m2以下とする。Furthermore, when the inner surface of the can is mainly used without painting and the content is filled with an organic solvent or the like, the anticorrosive effect of the coating film cannot be expected on the inner surface of the can. Becomes important. For example, since a gallon can is used for a long time after being opened, the head space portion on the inner surface side of the can is particularly exposed to a severe corrosive environment. Therefore, for such applications,
A steel sheet having an Sn plating adhesion amount of 300 to 500 mg / m 2 and a metal Cr layer having an adhesion amount of 100 to 200 mg / m 2 per one side of the steel plate is advantageously applicable. That is, the Sn plating adhesion amount is 500 mg /
If m 2 is exceeded, the appearance becomes white, the color tone of the electrolytic chromic acid-treated steel sheet cannot be obtained, and the economic efficiency is impaired due to an increase in the amount of Sn, so the upper limit is 500 mg / m 2 . On the other hand, the lower limit of the amount of Sn is 300 mg / m 2 in order to secure corrosion resistance on the inner surface of the can.
And Further, adhesion of the metal Cr layer is insufficient corrosion resistance becomes less than 100 mg / m 2, whereas the corrosion resistance is more than 200 mg / m 2 is in consideration of economic efficiency since it almost unchanged 20
0 mg / m 2 or less.
【0028】[0028]
【実施例】冷間圧延後未焼鈍の低炭素鋼板コイルを、連
続焼鈍ラインの入側に設置されたNiめっき設備に導い
て、常法による脱脂および水洗後に、表1に示すNiめっ
き条件にて所定量のNiめっきを施し、その後直ちに最高
温度及びその温度での保持時間として、700 ℃で10〜30
秒の条件で連続焼鈍を行って、鋼板の表面にNi拡散層を
形成した。次いで、調質圧延を施して板厚0.32mmおよび
硬さT4CAのめっき原板に仕上げた後、連続めっきライン
にて、表2に示す条件で所定量のSnめっきを施し、さら
に表3に示す条件で2ステップ法による電解クロム酸処
理を施し、めっき鋼板に仕上げた。かくして得られため
っき鋼板のコイルから、シャーラインにて板幅×1mの
切り板を切り出し、さらに剪断機により任意のサイズの
試験片に整えてから、以下に示す各種の品質評価に供し
た。なお、Ni付着量は蛍光X線法により測定し、Ni拡散
処理後の表面Ni濃度はオージェ電子分光法により同定
し、Snめっき付着量はJISG3303の電解剥離法にて、そし
て電解クロム酸処理皮膜の金属Cr層およびCr水和酸化物
層の付着量はJISG3315の蛍光X線法にて、それぞれ測定
した。また、各評価方法は次のとおりである。[Example] An unannealed low carbon steel coil after cold rolling was led to a Ni plating facility installed on the entrance side of a continuous annealing line, and after degreasing and washing with a conventional method, the Ni plating conditions shown in Table 1 were obtained. A predetermined amount of Ni plating is performed, and immediately thereafter, the maximum temperature and the holding time at that temperature are 10 to 30 at 700 ° C.
Continuous annealing was performed under the condition of seconds to form a Ni diffusion layer on the surface of the steel sheet. Next, after passivation rolling to finish a plating base plate having a plate thickness of 0.32 mm and a hardness of T4CA, a predetermined amount of Sn plating was performed on the continuous plating line under the conditions shown in Table 2, and further under the conditions shown in Table 3. And subjected to electrolytic chromic acid treatment by a two-step method to finish a plated steel sheet. From the coil of the plated steel sheet thus obtained, a cut sheet having a sheet width of 1 m was cut out with a shear line, and further prepared into test pieces of an arbitrary size by a shearing machine, and then subjected to various quality evaluations described below. The amount of Ni deposited was measured by the X-ray fluorescence method, the surface Ni concentration after the Ni diffusion treatment was identified by Auger electron spectroscopy, the amount of Sn plated was determined by the electrolytic peeling method of JIS G3303, and the electrolytic chromic acid-treated film Of the metal Cr layer and the Cr hydrated oxide layer were measured by the fluorescent X-ray method of JISG3315. Each evaluation method is as follows.
【0029】[0029]
【表1】 [Table 1]
【0030】[0030]
【表2】 [Table 2]
【0031】[0031]
【表3】 [Table 3]
【0032】〈めっき密着性評価方法〉供試材表面にセ
ロテープを張付けてから引き剥がし、該セロテープの粘
着面について、蛍光X線分析装置によりSnカウントを測
定し、セロテープ上にSnが検出されない場合は密着性良
好材 (記号◎) 、セロテープ上にSnが検出された場合は
密着性不良材 (記号×) とした。<Plating Adhesion Evaluation Method> A cell tape was stuck to the surface of the test material and then peeled off. The Sn count was measured on the adhesive surface of the cell tape by a fluorescent X-ray analyzer, and no Sn was detected on the cell tape. Is a material having good adhesion (symbol ◎), and a material having poor adhesion (symbol x) when Sn was detected on the cellophane tape.
【0033】〈溶接性評価方法〉図2に示す、スポット
溶接機を用いた動的抵抗測定装置により行った。すなわ
ち、同図に示すように、スポット溶接電極チップ1およ
び2間に、2枚の供試材3aおよび3bを重ねて配置し、こ
れら電極間に、図3に示す矩形波の溶接電流を通電し、
その際の一定電流値を示す時間帯において、重ね合わさ
れた供試材3aおよび3b間の抵抗値をモニターした。<Weldability evaluation method> The welding resistance was evaluated by a dynamic resistance measuring device using a spot welding machine as shown in FIG. That is, as shown in the figure, two test materials 3a and 3b are arranged in a superposed manner between the spot welding electrode tips 1 and 2, and a welding current of a rectangular wave shown in FIG. And
At that time, a resistance value between the superposed test materials 3a and 3b was monitored in a time zone showing a constant current value.
【0034】かくして測定されたスポット溶接時におけ
る抵抗を、動的抵抗と称する。この動的抵抗値の測定例
を図4に示すように、一般にぶりきのように溶接性の良
好なめっき鋼板は、図4に実線で示すように、初期の抵
抗値が低く時間と共に尻上がりに抵抗値が増加する挙動
を示す。これは鋼板が通電加熱されることにより、鋼板
バルクの抵抗が増加するからである。他方、通常の電解
クロム酸処理鋼板のように溶接性の悪い材料は、図4に
点線で示すように、初期に著しく高い抵抗値を示す。こ
れは、鋼板表面の接触抵抗が大きいためで、これにより
局部的な発熱が起こり、溶融した鋼板の塵が発生し易
い。すなわち、動的抵抗値の時間変化の波形および初期
抵抗値から、現実の製缶ラインでの溶接性を予想するこ
とができる。このようなスポット溶接時の動的抵抗挙動
が、実際の製缶ラインでの溶接性と相関があることは、
例えば、菊池利裕、望月一雄、久々湊英雄、表面技術、
vol.47 (1996) p.62-66 の報告にあるように、確認され
ている。従って、溶接性の評価は、動的抵抗値を測定す
ることによって行った。なお、溶接実験条件は表4に、
また溶接性の判定基準は表5に示すとおりである。The resistance during spot welding thus measured is called dynamic resistance. As shown in FIG. 4, a measurement example of the dynamic resistance value generally shows that a plated steel sheet having good weldability such as tinplate has a low initial resistance value and rises with time as shown by a solid line in FIG. It shows a behavior in which the resistance value increases. This is because the resistance of the steel sheet bulk increases when the steel sheet is electrically heated. On the other hand, a material having poor weldability, such as a normal electrolytic chromic acid-treated steel sheet, shows a remarkably high resistance value at the beginning as shown by a dotted line in FIG. This is because the contact resistance on the surface of the steel sheet is large, which causes local heat generation, which easily generates dust on the molten steel sheet. That is, the weldability in an actual can-making line can be estimated from the waveform of the dynamic resistance value with time and the initial resistance value. The fact that such dynamic resistance behavior at the time of spot welding has a correlation with the weldability in the actual can making line,
For example, Toshihiro Kikuchi, Kazuo Mochizuki, Hideo Kugaminato, surface technology,
vol.47 (1996), p.62-66. Therefore, the weldability was evaluated by measuring the dynamic resistance value. Table 4 shows the welding experimental conditions.
Table 5 shows the criteria for determining weldability.
【0035】[0035]
【表4】 [Table 4]
【0036】[0036]
【表5】 [Table 5]
【0037】〈塗料密着性評価方法〉供試材の片面にエ
ポキシフェノール系塗料を乾燥重量で50mg/m2 塗装後、
塗装面同士をナイロンフィルムにて圧着し、5mm×100m
m に切り出した試験片を用いて、図5に示すところに従
って、引張り速度100mm/min でのTピール剥離試験を行
って評価した。判定基準は表6に示すとおりである。<Evaluation Method of Coating Adhesion> An epoxyphenol-based coating was applied on one side of the test material at a dry weight of 50 mg / m 2 .
The painted surfaces are crimped with nylon film and 5mm x 100m
Using a test piece cut out to a length of m, a T-peel peel test was performed at a tensile speed of 100 mm / min according to the conditions shown in FIG. The criteria are shown in Table 6.
【0038】[0038]
【表6】 [Table 6]
【0039】〈塗装後耐食性評価方法〉供試材の片面に
エポキシフェノール系塗料を乾燥重量で50mg/m2 塗装
後、板厚×50mm×100mm に切り出し、端面をシールし
た。さらにカッターナイフにて、塗膜の上から素地鋼に
達するクロスカットを入れ、腐食液中に50℃×4日間浸
漬した後に乾燥し、クロスカット部の塗料をセロテープ
にて剥離した。その剥離幅で判定を行った。腐食液組成
を表7に、そして判定基準を表8に、それぞれ示した。<Evaluation method of corrosion resistance after coating> One surface of the test material was coated with an epoxyphenol-based paint at a dry weight of 50 mg / m 2 , cut out into a sheet thickness × 50 mm × 100 mm, and the end face was sealed. Further, a crosscut reaching the base steel from the top of the coating film was put with a cutter knife, immersed in a corrosive solution at 50 ° C. for 4 days, dried, and the paint at the crosscut portion was peeled off with cellophane tape. The judgment was made based on the peel width. The composition of the etchant is shown in Table 7 and the criteria are shown in Table 8.
【0040】[0040]
【表7】 [Table 7]
【0041】[0041]
【表8】 [Table 8]
【0042】〈裸耐食性評価方法〉供試材を板厚×50mm
×100mm に切り出し、試験片の半分まで腐食液に浸るよ
うにして硝子瓶に入れて密閉し、50℃×30日間の腐食促
進試験を行い、試験終了後に気液界面およびヘッドスペ
ース部の腐食状況を外観から判定した。腐食液として
は、市販の剥離剤および再生シンナーを用いた。判定基
準を表9に示した。<Natural corrosion resistance evaluation method>
× 100mm, cut into a glass bottle so that half of the test piece is immersed in the corrosive liquid, sealed and conducted a corrosion promotion test at 50 ° C for 30 days.After the test, the gas-liquid interface and the corrosion of the head space Was determined from the appearance. As the etchant, a commercially available release agent and a regenerated thinner were used. The criteria are shown in Table 9.
【0043】[0043]
【表9】 [Table 9]
【0044】〈外観評価方法〉目視評価により、通常の
電解クロム酸処理鋼板と同等と感じるかどうかで判定し
た。評価は、同等(◎)明らかに異なる(×)とした。<Appearance Evaluation Method> A visual evaluation was performed to judge whether or not it felt equivalent to a normal electrolytic chromic acid-treated steel sheet. The evaluation was equivalent (同等) and clearly different (x).
【0045】〈比較材のめっき条件〉比較材は、実施例
の供試材と同様の手順で作製し、Ni拡散処理の代わりに
Fe-Ni 合金めっきおよび極微量Niめっきを行ったもの
は、連続焼鈍前のNiめっきは行わずに、Snめっき直前に
表10に示す条件で、Fe-Ni 合金めっきあるいは極微量被
覆Niめっきを行った。<Plating conditions of comparative material> A comparative material was prepared in the same procedure as the test material of the example, and was replaced with a Ni diffusion treatment.
In the case of Fe-Ni alloy plating and trace Ni plating, Ni plating prior to continuous annealing was not performed, and Fe-Ni alloy plating or trace Ni coating was performed immediately before Sn plating under the conditions shown in Table 10. went.
【0046】[0046]
【表10】 [Table 10]
【0047】以上の各品質評価結果および皮膜の構成に
ついて、表11および12に示す。同表から、この発明に従
う実施例1〜18は、いずれも請求項1の要件を満足する
ため、めっき密着性および塗装後の耐食性に優れること
がわかる。すなわち、実施例1は、Sn付着量が少なく請
求項4の要件を満足しないためにシンナー中での裸耐食
性にやや劣るものの、請求項2および3の要件は満足す
るため、その他の品質に関しては問題なく、実施例2お
よび実施例3も、実施例1と同様である。なお、実施例
3は、Ni拡散層およびSnめっきを鋼板の片面側だけに有
する例である。Tables 11 and 12 show the results of each quality evaluation and the structure of the film. From the table, it can be seen that all of Examples 1 to 18 according to the present invention satisfy the requirements of Claim 1, and therefore have excellent plating adhesion and corrosion resistance after coating. That is, in Example 1, although the amount of Sn deposited was small and did not satisfy the requirement of Claim 4, bare corrosion resistance in thinner was slightly inferior. However, since the requirements of Claims 2 and 3 were satisfied, the other qualities were not satisfied. The second and third embodiments are similar to the first embodiment without any problem. Example 3 is an example in which a Ni diffusion layer and Sn plating are provided only on one side of a steel sheet.
【0048】[0048]
【表11】 [Table 11]
【0049】[0049]
【表12】 [Table 12]
【0050】また、実施例4はSn付着量が請求項3での
上限をこえるために剥離剤中での裸耐食性がやや劣る
が、その他の特性は全く問題がない。実施例5および6
は、さらにSn量が多いために塗料密着性、とりわけ剥離
剤中での裸耐食性に劣るが、請求項4の要件を満足する
ため、内容物としてシンナーを保持する無塗装缶として
は十分に使用可能である。なお、実施例6はNi拡散層お
よびSnめっきを鋼板の片面側だけに有する例である。In Example 4, since the amount of Sn deposited exceeds the upper limit of claim 3, the bare corrosion resistance in the release agent is slightly inferior, but there is no problem in other characteristics. Examples 5 and 6
Is inferior in paint adhesion, especially naked corrosion resistance in a release agent due to a large amount of Sn, but is sufficiently used as an unpainted can holding a thinner as a content to satisfy the requirements of claim 4. It is possible. Example 6 is an example having a Ni diffusion layer and Sn plating only on one side of a steel sheet.
【0051】次に、実施例7は、Sn量が少ないために溶
接性がやや劣ることと、シンナーに対する裸耐食性が不
十分な例である。ただし、請求項3の要件は満足してい
る。実施例8および9は、金属Cr量が請求項3および4
での下限より少ないために、裸使用時の耐食性が不十分
な例である。ただし、請求項2の要件を満足するため、
溶接性、塗料密着性、塗装後耐食性は十分であるので、
缶内面側を塗装して使用する用途には十分な品質を有す
る。Next, Example 7 is an example in which the weldability is slightly inferior due to the small amount of Sn, and the bare corrosion resistance to thinner is insufficient. However, the requirement of claim 3 is satisfied. In Examples 8 and 9, the amount of metal Cr is as defined in claims 3 and 4.
This is an example in which the corrosion resistance at the time of bare use is insufficient because the value is less than the lower limit in the above. However, in order to satisfy the requirements of claim 2,
Since the weldability, paint adhesion, and corrosion resistance after painting are sufficient,
It has sufficient quality for applications where the inner surface of the can is painted and used.
【0052】実施例10、11および12は、Sn付着量が請求
項4での範囲より少ないためにシンナー中での裸使用時
の耐食性が劣るが、請求項2および3の要件を満足する
ため、その他の環境で使用される場合には十分な品質を
示す。なお、実施例10および11は、Ni拡散層およびSnめ
っきを鋼板の片面側だけに有する例である。In Examples 10, 11 and 12, the corrosion resistance when barely used in a thinner is inferior because the Sn adhesion amount is less than the range in claim 4, but the requirements in claims 2 and 3 are satisfied. Demonstrate sufficient quality when used in other environments. Examples 10 and 11 are examples having the Ni diffusion layer and the Sn plating only on one side of the steel sheet.
【0053】実施例13は、Sn量が請求項2および3での
範囲よりも多いために、塗料密着性及び剥離剤中での裸
耐食性が劣化しているが、請求項4での要件を満足する
ため、内容物としてシンナーを保持する無塗装缶として
は十分に使用可能な例である。一方、実施例14は、Sn量
が請求項2および4での範囲よりも少ないために、溶接
性にやや劣るとともに、シンナー中での裸耐食性が劣化
しているが、請求項3の要件を満足しているため、内容
物としてアルカリ性の溶液を保持する無塗装缶としては
十分に使用可能な例である。In Example 13, since the amount of Sn was larger than the range of Claims 2 and 3, the paint adhesion and the bare corrosion resistance in the release agent were deteriorated. This is an example that can be used satisfactorily as an unpainted can holding a thinner as a content. On the other hand, in Example 14, since the amount of Sn was smaller than the range in claims 2 and 4, the weldability was slightly inferior, and the bare corrosion resistance in thinner was deteriorated. Since it is satisfied, it is an example which can be used sufficiently as an uncoated can holding an alkaline solution as a content.
【0054】実施例15は、請求項2の要件を満足する例
であり、請求項3および4での要求水準よりも金属Cr量
が少ないために、裸耐食性が劣化しているが、請求項2
の用件は満足しているため、塗装缶としては十分に使用
可能な例である。なお、実施例15は、Ni拡散層およびSn
めっきを鋼板の片面側だけに有する例である。Example 15 is an example that satisfies the requirement of claim 2, and the bare corrosion resistance is deteriorated because the amount of metal Cr is smaller than the required level of claims 3 and 4. 2
This is an example that can be sufficiently used as a painted can because the requirements are satisfied. In Example 15, the Ni diffusion layer and the Sn
This is an example in which plating is provided only on one side of a steel sheet.
【0055】実施例16は、請求項1および3を満足する
例であり、請求項2および4での要求水準よりもSn量が
少ないために、シンナー中での裸耐食性が劣化してい
る。また、Sn量が請求項3の上限であるために、内容物
としてアルカリ性の溶液を保持する無塗装缶として、耐
食性がやや劣るものの適用可能である。なお、実施例16
は、Ni拡散層およびSnめっきを鋼板の片面側だけに有す
る例である。Example 16 is an example that satisfies Claims 1 and 3, in which the amount of Sn is smaller than the required level in Claims 2 and 4, so that the bare corrosion resistance in thinner is deteriorated. Further, since the amount of Sn is the upper limit of the third aspect, an uncoated can that holds an alkaline solution as the content can be used although the corrosion resistance is slightly inferior. Example 16
Is an example having a Ni diffusion layer and Sn plating only on one side of a steel sheet.
【0056】実施例17は、金属Cr量が請求項3での範囲
よりも少なく、かつSn付着量が請求項3の範囲よりも多
いために、裸使用時の耐食性が不十分な例であるが、請
求項2での要件を満足するために溶接性、塗料密着性、
塗装後耐食性は十分であり、缶内面側を塗装して使用す
る用途には十分な品質である。Example 17 is an example in which the corrosion resistance at the time of bare use is insufficient because the amount of metal Cr is smaller than the range of claim 3 and the amount of Sn adhesion is larger than the range of claim 3. However, in order to satisfy the requirements of claim 2, weldability, paint adhesion,
The corrosion resistance after painting is sufficient, and the quality is sufficient for applications where the inner surface of the can is painted and used.
【0057】実施例18は、Sn付着量が請求項3での上限
よりも多くかつ請求項4での下限よりも少ないために、
裸で使用する場合はアルカリ性の溶液中でもシンナー中
でも、何れの場合にも不十分であり、また金属Cr量が請
求項2の上限よりも多く、ややオーバースペックである
という問題はあるが、塗装して使用される場合の耐食性
は抜群である。なお、実施例18は、Ni拡散層およびSnめ
っきを鋼板の片面側だけに有する例である。In Example 18, the amount of Sn deposited was larger than the upper limit in claim 3 and smaller than the lower limit in claim 4,
When used naked, both in alkaline solution and in thinner, it is insufficient in any case, and there is a problem that the amount of metal Cr is larger than the upper limit of claim 2 and is slightly over-specified. The corrosion resistance is excellent when used. Example 18 is an example in which a Ni diffusion layer and Sn plating are provided only on one side of a steel sheet.
【0058】次に、比較例1および比較例2は、いずれ
もNi拡散層のNi濃度が20wt%以上であるために、耐食性
が劣化した例である。この結果から、Ni拡散層のNi濃度
を制御することは、非常に重要な要件であることが良く
わかる。Next, Comparative Examples 1 and 2 are examples in which the corrosion resistance deteriorates because the Ni concentration of the Ni diffusion layer is 20 wt% or more. From this result, it is well understood that controlling the Ni concentration of the Ni diffusion layer is a very important requirement.
【0059】比較例3は、Sn量がこの発明の範囲よりも
多い例であり、塗料密着性および剥離剤中での裸耐食性
が劣化するとともに、外観が通常の電解クロム酸処理鋼
板とは異なるものになり、ユーザーに受け入れられない
例である。比較例4は、表面にSnめっきがないため、溶
接性が不十分である例である。Comparative Example 3 is an example in which the amount of Sn is larger than the range of the present invention, and the paint adhesion and the bare corrosion resistance in a release agent are deteriorated, and the appearance is different from that of a normal electrolytic chromic acid-treated steel sheet. This is an example that is unacceptable to users. Comparative Example 4 is an example in which weldability is insufficient because there is no Sn plating on the surface.
【0060】比較例5は、金属Crの付着量が少なく、塗
料密着性および耐食性に劣る例である。比較例6は、金
属Cr量が請求項1での上限をこえるため、外観が悪くて
ユーザーには受け入れられないものである。また、Sn付
着量が請求項3の上限よりも多くかつ請求項4の下限よ
りも少ないために、裸で使用する場合はアルカリ性の溶
液中でもシンナー中でも、何れの場合にも不十分であ
る。Comparative Example 5 is an example in which the amount of adhering metal Cr is small and the paint adhesion and the corrosion resistance are poor. In Comparative Example 6, since the amount of metallic Cr exceeded the upper limit of Claim 1, the appearance was poor and unacceptable to the user. In addition, since the amount of Sn deposited is larger than the upper limit of claim 3 and smaller than the lower limit of claim 4, when used naked, it is insufficient in both alkaline solutions and thinners.
【0061】比較例7は、Cr水和酸化物の付着量が少な
く、塗料密着性及び耐食性に劣る例である。比較例8
は、Snめっきをリフローした例であり、溶接性が悪くて
缶用鋼板として使用することはできない。比較例9は、
Cr水和酸化物層の付着量が多すぎるために、外観が悪く
製品とはならない。比較例10は、素地鋼板表面にNi拡散
層がないために、ノーリフローのSnめっきの密着性が悪
く、全く使用することができない例である。なお、めっ
き密着性以外の評価は行わなかった。Comparative Example 7 is an example in which the amount of Cr hydrated oxide adhered was small and paint adhesion and corrosion resistance were poor. Comparative Example 8
Is an example of reflowing Sn plating, which has poor weldability and cannot be used as a steel plate for cans. Comparative Example 9
Since the amount of the Cr hydrated oxide layer is too large, the appearance is poor and the product is not obtained. Comparative Example 10 is an example in which no Ni-diffusion layer is present on the surface of the base steel sheet, so that the adhesion of the no-reflow Sn plating is poor, and it cannot be used at all. In addition, evaluation other than plating adhesion was not performed.
【0062】比較例11は、Ni拡散処理の代わりに、Snめ
っき直前に電気めっき法によりFe−Ni合金めっきを行っ
て、Fe−Ni合金中のNi含有量を40mg/m2 かつ表面のNi濃
度を10wt%とした他は、実施例2と同様の皮膜構成に成
る例である。既に述べたように、このような場合は、め
っき密着性と耐食性が不十分である。比較例12は、Ni拡
散処理の代わりに、Snめっき直前に電気めっき法により
微量のNi合金めっきを行って表面のNi濃度を見かけ上18
wt%とした他は、実施例2と同様の皮膜構成に成る例で
ある。既に述べたように、このような場合は、めっき密
着性と耐食性が不十分である。In Comparative Example 11, instead of the Ni diffusion treatment, an Fe—Ni alloy plating was performed by electroplating just before Sn plating to reduce the Ni content in the Fe—Ni alloy to 40 mg / m 2 and the Ni This is an example in which the film configuration is the same as that in Example 2 except that the concentration is 10 wt%. As described above, in such a case, plating adhesion and corrosion resistance are insufficient. In Comparative Example 12, instead of Ni diffusion treatment, a slight amount of Ni alloy plating was performed by electroplating immediately before Sn plating, and the Ni concentration on the surface was apparently 18
This example is an example in which the coating composition is the same as that of the second embodiment except that wt% is used. As described above, in such a case, plating adhesion and corrosion resistance are insufficient.
【0063】[0063]
【発明の効果】この発明によれば、電解クロム酸処理鋼
板の溶接性を飛躍的に向上し、かつめっきの密着性にも
優れ、さらに塗料密着性、塗装後耐食性、裸耐食性およ
び外観に優れた材料が得られる。According to the present invention, the weldability of the electrolytic chromic acid-treated steel sheet is remarkably improved, the adhesion of plating is excellent, and the paint adhesion, post-coat corrosion resistance, bare corrosion resistance and appearance are excellent. Material is obtained.
【図1】オージェ電子分光法による測定を行った際に得
られる、深さ方向プロファイルの典型例を示す図であ
る。FIG. 1 is a diagram showing a typical example of a depth direction profile obtained when measurement is performed by Auger electron spectroscopy.
【図2】動的抵抗測定装置を示す模式図である。FIG. 2 is a schematic diagram showing a dynamic resistance measuring device.
【図3】動的抵抗測定時の溶接電流波形を示す図であ
る。FIG. 3 is a diagram showing a welding current waveform during dynamic resistance measurement.
【図4】動的抵抗の測定例を示す図である。FIG. 4 is a diagram showing a measurement example of dynamic resistance.
【図5】Tピール剥離試験の引張り方法を示す図であ
る。FIG. 5 is a diagram showing a tension method in a T-peel peel test.
1,2 スポット溶接電極チップ 3a,3b 供試材 1, 2 Spot welding electrode tips 3a, 3b Test material
───────────────────────────────────────────────────── フロントページの続き (72)発明者 赤尾 謙一郎 千葉県千葉市中央区川崎町1番地 川崎製 鉄株式会社技術研究所内 (72)発明者 稲永 章子 千葉県千葉市中央区川崎町1番地 川崎製 鉄株式会社技術研究所内 (72)発明者 加藤 俊之 千葉県千葉市中央区川崎町1番地 川崎製 鉄株式会社技術研究所内 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kenichiro Akao 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside the Technical Research Institute of Kawasaki Steel Co., Ltd. (72) Inventor: Toshiyuki Kato 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Pref.
Claims (4)
が1wt%以上20wt%未満のNi拡散層および、該Ni拡散層
上にリフローすることなく形成した、鋼板片面当たりの
付着量が20〜500mg/m2のSnめっきを有し、さらに鋼板両
面の最外層を、鋼板片面当たりの付着量が30〜200mg/m2
の金属Cr層および同付着量がCr換算で4〜18mg/m2 のク
ロム水和酸化物層による表面被膜で覆って成ることを特
徴とするめっき密着性および耐食性に優れた無研削での
溶接が可能な電解クロム酸処理鋼板。An Ni diffusion layer having a Ni concentration of 1 wt% or more and less than 20 wt% on at least one side of a steel sheet, and an adhesion amount per side of the steel sheet formed on the Ni diffusion layer without reflow of 20 to 20% by weight. 500 mg / m 2 of having a Sn plating, further the outermost layer of the steel sheet both sides, coating weight of 30 to 200 mg / m 2 per steel sided
Non-grinding with excellent plating adhesion and corrosion resistance, characterized by being covered with a surface coating of a chromium hydrated oxide layer with a metal Cr layer of 4 to 18 mg / m 2 in equivalent Cr as Cr Electrolytic chromic acid treated steel sheet.
金属Cr層の付着量が30〜120mg/m2である請求項1に記載
の電解クロム酸処理鋼板。2. The electrolytic chromic acid-treated steel sheet according to claim 1, wherein the adhesion amount of the Sn plating is 50 to 300 mg / m 2 and the adhesion amount of the metal Cr layer is 30 to 120 mg / m 2 .
金属Cr層の付着量が80〜200mg/m2である請求項1に記載
の電解クロム酸処理鋼板。3. The electrolytic chromic acid-treated steel sheet according to claim 1, wherein the adhesion amount of the Sn plating is 20 to 200 mg / m 2 and the adhesion amount of the metal Cr layer is 80 to 200 mg / m 2 .
び金属Cr層の付着量が100 〜200mg/m2である請求項1に
記載の電解クロム酸処理鋼板。4. The electrolytic chromic acid-treated steel sheet according to claim 1, wherein the adhesion amount of the Sn plating is 300 to 500 mg / m 2 and the adhesion amount of the metal Cr layer is 100 to 200 mg / m 2 .
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10133056A JPH1129897A (en) | 1997-05-15 | 1998-05-15 | Electrolytic chromic acid-treated steel sheet being excellent in plating adhesion and corrosion resistance and weldable without grinding |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9-125429 | 1997-05-15 | ||
JP12542997 | 1997-05-15 | ||
JP10133056A JPH1129897A (en) | 1997-05-15 | 1998-05-15 | Electrolytic chromic acid-treated steel sheet being excellent in plating adhesion and corrosion resistance and weldable without grinding |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH1129897A true JPH1129897A (en) | 1999-02-02 |
Family
ID=26461870
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP10133056A Withdrawn JPH1129897A (en) | 1997-05-15 | 1998-05-15 | Electrolytic chromic acid-treated steel sheet being excellent in plating adhesion and corrosion resistance and weldable without grinding |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH1129897A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20240035182A1 (en) * | 2020-12-21 | 2024-02-01 | Jfe Steel Corporation | Surface-treated steel sheet and method of producing the same |
US20240068107A1 (en) * | 2020-12-21 | 2024-02-29 | Jfe Steel Corporation | Surface-treated steel sheet and method of producing the same |
-
1998
- 1998-05-15 JP JP10133056A patent/JPH1129897A/en not_active Withdrawn
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20240035182A1 (en) * | 2020-12-21 | 2024-02-01 | Jfe Steel Corporation | Surface-treated steel sheet and method of producing the same |
US20240068107A1 (en) * | 2020-12-21 | 2024-02-29 | Jfe Steel Corporation | Surface-treated steel sheet and method of producing the same |
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Legal Events
Date | Code | Title | Description |
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A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20050802 |