JPH08269780A - Plated steel sheet with excellent corrosion resistance and method for producing the same - Google Patents
Plated steel sheet with excellent corrosion resistance and method for producing the sameInfo
- Publication number
- JPH08269780A JPH08269780A JP7340594A JP34059495A JPH08269780A JP H08269780 A JPH08269780 A JP H08269780A JP 7340594 A JP7340594 A JP 7340594A JP 34059495 A JP34059495 A JP 34059495A JP H08269780 A JPH08269780 A JP H08269780A
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- Japan
- Prior art keywords
- steel sheet
- plating layer
- corrosion resistance
- plating
- zinc
- 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.)
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Abstract
(57)【要約】
【課題】 自動車用防錆鋼板として必要な高耐食性およ
び優れたスポット溶接性を有する低コストのめっき鋼板
およびその製造方法の提供。
【解決手段】 鋼板表面にFe−Ｐ−Ｏめっき層を有する
耐食性に優れためっき鋼板ならびに亜鉛系めっき層と鋼
板との界面にFe−Ｐ−Ｏめっき層を有する耐食性に優れ
ためっき鋼板、および鋼板を、Ｆｅイオンを含有しかつ
燐酸系化合物を含有するめっき浴中で電気めっきし、鋼
板表面にFe−Ｐ−Ｏめっき層を形成する耐食性に優れた
めっき鋼板の製造方法ならびに鋼板表面にFe−Ｐ−Ｏめ
っき層を形成した後、該めっき層上に亜鉛系めっき層を
形成する耐食性に優れためっき鋼板の製造方法。(57) [Abstract] [PROBLEMS] To provide a low-cost plated steel sheet having high corrosion resistance and excellent spot weldability required as an anticorrosive steel sheet for automobiles, and a method for producing the same. A plated steel sheet having a Fe—P—O plating layer on the surface of a steel sheet and excellent in corrosion resistance, and a plated steel sheet having a Fe—P—O plating layer at the interface between the zinc-based plating layer and the steel sheet and having excellent corrosion resistance, and A steel sheet is electroplated in a plating bath containing Fe ions and a phosphoric acid compound to form a Fe-PO plating layer on the steel sheet surface. -A method for producing a plated steel sheet having excellent corrosion resistance, which comprises forming a zinc-based plating layer on the plating layer after forming the P-O plating layer.
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、自動車用防錆鋼板
などに有用な、特に著しく耐食性に優れためっき鋼板な
らびに該めっき鋼板を母材とした亜鉛系めっき鋼板、お
よびそれら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 galvanized steel sheet which is particularly useful as an anticorrosive steel sheet for automobiles and which has particularly excellent corrosion resistance, a zinc-based galvanized steel sheet using the galvanized steel sheet as a base material, and a method for producing the same. Is.
【０００２】[0002]
【従来の技術】近年、自動車、家電などの分野において
高耐食性を有する表面処理鋼板の開発が切望されてい
る。中でも、亜鉛めっき層の優れた犠牲防食能のために
高耐食性を有する電気亜鉛めっき鋼板、溶融亜鉛めっき
鋼板が自動車をはじめ各分野で実用化されている。2. Description of the Related Art In recent years, the development of surface-treated steel sheets having high corrosion resistance has been earnestly desired in fields such as automobiles and home appliances. Among them, electrogalvanized steel sheets and hot-dip galvanized steel sheets having high corrosion resistance due to the excellent sacrificial anticorrosive ability of the galvanized layer have been put to practical use in various fields including automobiles.
【０００３】しかしながら、これら純亜鉛系のめっき鋼
板を使用する場合に十分な耐食性を確保しようとすると
必然的にめっき付着量を増加させる必要があり、これに
よって自動車用鋼板として要求される諸性能、例えばス
ポット溶接性などが劣化するという問題が生じる。ま
た、溶接性以外にも付着量の増加はコストの点からも不
利である。However, in order to ensure sufficient corrosion resistance when using these pure zinc-based plated steel sheets, it is necessary to increase the coating adhesion amount, which leads to various performances required for automobile steel sheets, For example, there arises a problem that spot weldability deteriorates. In addition to weldability, increasing the amount of adhesion is also disadvantageous in terms of cost.
【０００４】このような問題を解決すべく、亜鉛を合金
化させることにより高耐食性を付与させる技術が開発さ
れ、例えば電気亜鉛めっき系ではZn−Ni合金めっき鋼
板、Zn−Fe合金めっき鋼板など、自動車用として要求さ
れる優れた耐食性とその他の諸性能とを兼備しためっき
鋼板が開発されてきた。この合金めっき鋼板の出現によ
り、上述の問題はある程度まで解決された。In order to solve such problems, a technique for imparting high corrosion resistance by alloying zinc has been developed. For example, in the electrogalvanizing system, a Zn-Ni alloy-plated steel sheet, a Zn-Fe alloy-plated steel sheet, etc. A plated steel sheet having both excellent corrosion resistance and various other properties required for automobiles has been developed. With the advent of this alloy-plated steel sheet, the above problems have been solved to some extent.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、これら
の合金めっき鋼板を自動車用防錆鋼板として使用した場
合であっても、自動車の防錆、特に、耐孔あき腐食に必
要な耐食性を確保するために現在使用されているめっき
鋼板のめっきの付着量は、合金化溶融亜鉛めっき鋼板の
場合で45ｇ／ｍ2 程度となっており、Zn−Ni合金めっき
鋼板の場合は20〜30ｇ／ｍ2 程度であり、さらに有機被
覆が必要となっている。However, even when these alloy-plated steel sheets are used as rust-preventing steel sheets for automobiles, in order to secure the rust-prevention of automobiles, in particular, the corrosion resistance necessary for pitting corrosion resistance. adhesion amount of the plating of the plated steel sheet that is currently used is a 45 g / m 2 approximately in the case of galvannealed steel sheets, in the case of Zn-Ni alloy plated steel sheet 20 to 30 g / m 2 approximately Therefore, an organic coating is required.
【０００６】このため、これらと同等の耐食性を有する
めっき付着量の多い純亜鉛系のめっき鋼板に比較すると
スポット溶接性は向上しているものの、いまだ冷延鋼板
などと比較した場合、スポット溶接性が劣るという本質
的な問題を抱えている。また、合金めっき鋼板のコスト
に関しては決して満足できる水準とは言い難い。本発明
は、自動車用防錆鋼板として必要な高耐食性および優れ
たスポット溶接性を有する低コストのめっき鋼板、およ
びその製造方法を提供することを目的とするものであ
る。Therefore, although the spot weldability is improved as compared with a pure zinc-based plated steel sheet having a corrosion resistance equivalent to those of the above and having a large amount of plating adhered, when compared with a cold rolled steel sheet or the like, the spot weldability is still high. It has the essential problem of being inferior. Further, it is hard to say that the cost of the alloy-plated steel sheet is at a satisfactory level. It is an object of the present invention to provide a low cost plated steel sheet having high corrosion resistance and excellent spot weldability required as an anticorrosive steel sheet for automobiles, and a method for producing the same.
【０００７】[0007]
【課題を解決するための手段】第１の発明は、鋼板表面
にFe−Ｐ−Ｏめっき層を有することを特徴とする耐食性
に優れためっき鋼板である。また、第２の発明は、亜鉛
系めっき層と鋼板との界面にFe−Ｐ−Ｏめっき層を有す
ることを特徴とする耐食性に優れためっき鋼板である。A first aspect of the present invention is a plated steel sheet having excellent corrosion resistance, which is characterized by having a Fe-P-O plating layer on the surface of the steel sheet. A second invention is a plated steel sheet having excellent corrosion resistance, which has an Fe-P-O plating layer at the interface between the zinc-based plating layer and the steel sheet.
【０００８】また、第３の発明は、鋼板を、Ｆｅイオン
を含有しかつ燐酸系化合物を含有するめっき浴中で電気
めっきし、鋼板表面にFe−Ｐ−Ｏめっき層を形成するこ
とを特徴とする耐食性に優れためっき鋼板の製造方法で
ある。さらに、第４の発明は、鋼板を、Ｆｅイオンを含
有しかつ燐酸系化合物を含有するめっき浴中で電気めっ
きし、鋼板表面にFe−Ｐ−Ｏめっき層を形成した後、該
めっき層上に亜鉛系めっき層を形成することを特徴とす
る耐食性に優れためっき鋼板の製造方法である。A third invention is characterized in that a steel sheet is electroplated in a plating bath containing Fe ions and a phosphoric acid compound to form an Fe-PO plating layer on the surface of the steel sheet. Is a method for producing a plated steel sheet having excellent corrosion resistance. Further, a fourth invention is that a steel sheet is electroplated in a plating bath containing Fe ions and a phosphoric acid compound to form a Fe-PO plating layer on the surface of the steel sheet, and then, on the plating layer. A method for producing a plated steel sheet having excellent corrosion resistance, characterized in that a zinc-based plating layer is formed on.
【０００９】前記第３の発明および第４の発明において
は、前記めっき浴が、さらに加えてアルカリ金属のクエ
ン酸塩を含有することが好ましい。さらに、前記第１の
発明、第２の発明、第３の発明および第４の発明におい
ては、Fe−Ｐ−Ｏめっき層中のＰ含有率が 0.001〜10wt
％、より好ましくは0.01〜10wt％、さらに好ましくは
0.4〜3.0 wt％、酸素含有率が 0.001〜10wt％、より好
ましくは0.01〜10wt％、さらに好ましくは 0.5〜5.0 wt
％であることが好ましく、さらにはFe−Ｐ−Ｏめっき層
のめっき付着量が鋼板片面当り 0.1〜10ｇ／ｍ 2 である
ことが好ましい。In the third and fourth inventions
In addition to the above-mentioned plating bath,
It is preferable to contain a phosphate. Further, the first
In the invention, the second invention, the third invention and the fourth invention
The Fe content in the Fe-PO layer was 0.001-10wt%.
%, More preferably 0.01 to 10 wt%, even more preferably
0.4 to 3.0 wt%, oxygen content 0.001 to 10 wt%, better
It is preferably 0.01 to 10 wt%, more preferably 0.5 to 5.0 wt%
%, More preferably Fe-PO plating layer
The amount of plating applied is 0.1-10g / m per side of steel plate 2Is
Is preferred.
【００１０】また、前記第１の発明、第２の発明、第３
の発明および第４の発明においては、鋼板の少なくとも
片面に、前記Fe−Ｐ−Ｏめっき層、または前記Fe−
Ｐ−Ｏめっき層および亜鉛系めっき層の両層を有する。The first invention, the second invention, and the third invention
In the invention and the fourth invention, the Fe—P—O plating layer or the Fe—
It has both a P-O plating layer and a zinc-based plating layer.
【００１１】[0011]
【発明の実施の形態】以下、本発明をさらに詳細に説明
する。本発明によれば、Fe−Ｐ−Ｏめっき層を鋼板表
面または亜鉛系めっき層と鋼板の界面に形成させるこ
とにより、鋼板の耐食性は総合的に著しく向上する。こ
の結果、鋼板を亜鉛系めっきなしで使用する場合は、従
来の冷延鋼板に比較して格段に鋼板の寿命が延びる。BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. According to the present invention, by forming the Fe-PO layer on the surface of the steel sheet or at the interface between the zinc-based plating layer and the steel sheet, the corrosion resistance of the steel sheet is significantly improved overall. As a result, when the steel sheet is used without zinc-based plating, the life of the steel sheet is remarkably extended as compared with the conventional cold-rolled steel sheet.
【００１２】また、Fe−Ｐ−Ｏめっき鋼板を母材とし
て、さらに亜鉛系めっきを施す場合には、Fe−Ｐ−Ｏめ
っき層と亜鉛系めっき層との相乗効果により、さらに耐
食性が向上する。この結果、少なくともFe−Ｐ−Ｏめっ
きとその上層に亜鉛系めっきを有する複層めっき鋼板
は、従来の合金めっき鋼板と同等の耐食性を発現させる
ために必要なめっき層の亜鉛付着量を大幅に低減させる
ことが可能となり、性能面で溶接性を向上させるだけで
なく、製造コストも効果的に低減させることが可能とな
る。Further, when zinc-based plating is further performed using a Fe-P-O plated steel sheet as a base material, the synergistic effect of the Fe-P-O plated layer and the zinc-based plated layer further improves the corrosion resistance. . As a result, the multi-layer plated steel sheet having at least Fe-P-O plating and the zinc-based plating on the upper layer has a significantly large zinc adhesion amount of the plating layer required to develop corrosion resistance equivalent to that of the conventional alloy plated steel sheet. Therefore, not only the weldability can be improved in terms of performance, but also the manufacturing cost can be effectively reduced.
【００１３】亜鉛系めっき鋼板の防食機構は、亜鉛本来
の犠牲防食能および腐食環境に塩素イオンを含む場合に
生成される腐食生成物（塩基性塩化亜鉛）の障壁効果で
説明されている。また、この腐食生成物は亜鉛めっき層
中にNiなどの合金元素が含まれる場合に安定化され、よ
り長期間にわたり保持されることが示されている。The anticorrosion mechanism of the zinc-based plated steel sheet is explained by the sacrificial anticorrosion ability inherent to zinc and the barrier effect of the corrosion product (basic zinc chloride) produced when chlorine ions are contained in the corrosive environment. It is also shown that this corrosion product is stabilized and retained for a longer period of time when an alloying element such as Ni is contained in the galvanized layer.
【００１４】しかしながら、たとえめっき層中に腐食生
成物の安定化元素が含まれていても腐食の進行につれて
この腐食生成物は溶け出し、この亜鉛系の腐食生成物が
なくなった後は、鋼板は全くめっき層を有さない材料と
同等の速度で腐食が進行していくことになる。本発明者
らは、亜鉛系めっき鋼板の耐食性を向上させるにあた
り、腐食生成物が消失したあとの鋼板の腐食速度につい
て注目し、鋼板腐食速度の低減について研究を続けた結
果、鋼板表面にFe−Ｐ−Ｏめっき層を形成することに
より、鋼板の耐食性が向上し、従来の冷延鋼板に比較し
て格段に鋼板の寿命が延びること（第１の発明、第３の
発明）、さらに亜鉛めっき層と鋼板の間に一定量のＰ
と酸素を含有するFeめっき層を存在させることで、亜鉛
系の腐食生成物が腐食過程で消失したあとでの鋼板の腐
食速度を著しく低減させ、亜鉛系めっき層との相乗効果
により、耐食性を著しく向上させることが可能であるこ
と（第２の発明、第４の発明）を見出した。However, even if the plating layer contains a stabilizing element for the corrosion product, this corrosion product will dissolve as the corrosion progresses, and after the zinc-based corrosion product disappears, the steel sheet Corrosion proceeds at the same rate as a material having no plated layer at all. In order to improve the corrosion resistance of the zinc-based plated steel sheet, the present inventors paid attention to the corrosion rate of the steel sheet after the corrosion product disappeared, and as a result of continuing the research on the reduction of the steel sheet corrosion rate, Fe- By forming the P-O plating layer, the corrosion resistance of the steel sheet is improved, and the life of the steel sheet is remarkably extended as compared with the conventional cold-rolled steel sheet (first invention, third invention), and further galvanized. A certain amount of P between the layer and the steel plate
The presence of the Fe plating layer containing oxygen and oxygen significantly reduces the corrosion rate of the steel sheet after the zinc-based corrosion product disappears in the corrosion process, and increases the corrosion resistance by the synergistic effect with the zinc-based plating layer. It has been found that it is possible to remarkably improve (second invention, fourth invention).
【００１５】前記第２の発明、第４の発明における耐食
性の向上効果は、単にFe−Ｐ−Ｏめっき層により鋼板そ
のものの耐食性が改善されたことにより具現したもので
はなく、亜鉛めっき層との相乗効果によるものである。
すなわち、亜鉛系めっき層の亜鉛と接触した状態でFe−
Ｐ−Ｏめっき層が腐食した際に生成される緻密な鉄系腐
食生成物による障壁効果により、鋼板自体の初期腐食が
著しく抑制されることにより本発明の効果が発現する。The effect of improving the corrosion resistance in the second invention and the fourth invention is not embodied simply because the corrosion resistance of the steel sheet itself is improved by the Fe--P--O plating layer, and is not realized by the zinc plating layer. This is due to the synergistic effect.
That is, in the state of contacting with zinc of the zinc-based plating layer, Fe-
Due to the barrier effect of the dense iron-based corrosion product generated when the P-O plated layer is corroded, the effect of the present invention is exerted by significantly suppressing the initial corrosion of the steel sheet itself.
【００１６】本発明においては、鋼板表面または亜鉛系
めっき層と鋼板との界面に存在する鉄めっき層には燐お
よび酸素が含有されることが必須であるが、この理由は
以下による。すなわち、本発明の効果は、鋼板表面また
は亜鉛系めっき層と鋼板の界面に生成される緻密な鉄系
腐食生成物により発現し、かつこの腐食生成物はFe−Ｐ
−Ｏめっきの腐食により生じるものである。In the present invention, it is essential that the iron plating layer existing on the surface of the steel sheet or at the interface between the zinc-based plating layer and the steel sheet contains phosphorus and oxygen, for the following reason. That is, the effect of the present invention is exhibited by the dense iron-based corrosion product formed on the surface of the steel plate or the interface between the zinc-based plating layer and the steel plate, and this corrosion product is Fe-P.
-O It is caused by corrosion of the plating.
【００１７】この腐食生成物は、通常の鋼板が腐食した
際に生成される鉄系腐食生成物とは異なり、予めFe−Ｐ
−Ｏめっき層自体が一定量の酸素を含有することにより
酸素、水、塩素イオンなどの腐食因子に対して障壁効果
が顕著である鉄系腐食生成物が生成されることになる。
また、さらにFeめっき層中のＰにより、この鉄系腐食生
成物は安定に保持され溶出しにくくなり、長期間にわた
り鋼板上に保護皮膜を形成することになる。This corrosion product is different from the iron-based corrosion product generated when a normal steel plate is corroded, and is previously Fe--P.
Since the -O plating layer itself contains a certain amount of oxygen, an iron-based corrosion product having a remarkable barrier effect against corrosion factors such as oxygen, water, and chlorine ions is generated.
Further, due to P in the Fe plating layer, this iron-based corrosion product is stably held and hardly eluted, and a protective film is formed on the steel sheet for a long period of time.
【００１８】さらには、このFe−Ｐ−Ｏめっき層の上に
亜鉛めっき層が存在することにより、Fe−Ｐ−Ｏめっき
が腐食する際の腐食環境が亜鉛めっき層および亜鉛系腐
食生成物の存在下での環境に変化する。この時、溶存酸
素濃度、塩素イオン濃度、ｐＨなどの腐食環境は上記鉄
系腐食生成物をより一層緻密な皮膜とするのに有利な雰
囲気に変化し、耐食性の向上に有利に作用する。Furthermore, the presence of the zinc plating layer on the Fe--P--O plating layer causes the corrosion environment when the Fe--P--O plating is corroded to be a zinc plating layer and a zinc-based corrosion product. Changes to the existing environment. At this time, the corrosive environment such as the dissolved oxygen concentration, the chloride ion concentration, and the pH is changed into an atmosphere that is advantageous for forming the iron-based corrosion product into a more dense film, and the corrosion resistance is advantageously improved.
【００１９】以上の機構により、耐食性に対するFe−
Ｐ−Ｏめっき層の効果、または亜鉛系めっき層とFe−
Ｐ−Ｏめっき層との相乗効果が発現する。本発明では、
Fe−Ｐ−Ｏめっき層中のＰ含有率が 0.001〜10wt％、よ
り好ましくは0.01〜10wt％、さらに好ましくは 0.4〜3.
0 wt％、酸素含有率が 0.001〜10wt％、より好ましくは
0.01〜10wt％、さらに好ましくは 0.5〜5.0 wt％である
ことが好ましい。With the above mechanism, Fe-
Effect of P-O plating layer, or zinc-based plating layer and Fe-
A synergistic effect with the P-O plating layer is developed. In the present invention,
The P content in the Fe-P-O plating layer is 0.001 to 10 wt%, more preferably 0.01 to 10 wt%, still more preferably 0.4 to 3.
0 wt%, oxygen content is 0.001-10 wt%, more preferably
It is preferably 0.01 to 10 wt%, more preferably 0.5 to 5.0 wt%.
【００２０】Ｐの含有率が 0.001wt％より少ないと、先
に述べた鉄系腐食生成物の安定効果が不十分で鋼板上に
生成される保護皮膜は短時間のうちに消失してしまい、
耐食性の向上効果が少なく、Ｐの含有率が10wt％を超え
ると、先に述べた鉄系腐食生成物の安定効果が飽和し、
コスト的に不利となる。また、酸素の含有率が 0.001wt
％より低いと十分な障壁効果のある鉄系腐食生成物が生
成しにくくなるため、酸素の含有率は 0.001wt％以上が
好ましく、酸素の含有率が10wt％を超えると、耐食性改
善効果が飽和するため経済的に不利になるばかりでな
く、Fe−Ｐ−Ｏめっきを施した後に行う亜鉛系めっき時
に、めっき密着性が悪くなり場合によっては不めっきが
生じることがある。When the P content is less than 0.001 wt%, the above-mentioned stabilizing effect of the iron-based corrosion product is insufficient and the protective film formed on the steel sheet disappears in a short time.
If the effect of improving the corrosion resistance is small and the P content exceeds 10 wt%, the stabilizing effect of the iron-based corrosion product described above is saturated,
It is a cost disadvantage. The oxygen content is 0.001wt
%, It is difficult to produce iron-based corrosion products with a sufficient barrier effect, so the oxygen content is preferably 0.001 wt% or more, and when the oxygen content exceeds 10 wt%, the corrosion resistance improving effect is saturated. As a result, not only is it economically disadvantageous, but the zinc-based plating performed after the Fe—P—O plating is performed may result in poor plating adhesion and, in some cases, non-plating may occur.
【００２１】また、本発明ではFe−Ｐ−Ｏめっき層のめ
っき付着量は特に限定するものではないが、実現可能な
値として鋼板片面当たり、Fe，Ｐ，Ｏの合計量として
0.1〜10ｇ／ｍ2 とすることが性能およびコスト面から
好ましい。なお、本発明においては、Fe−Ｐ−Ｏめっき
層のめっき層中にNi、Cu、Co、Cr、Mn、Mg、Ｃ、Ｂ、
Ｎ、Al、Si、Ca、Ti、Nb、Mo、Sn、SbおよびBiからなる
群から選ばれた少なくとも一種の元素が含まれいてもよ
い。In the present invention, the coating amount of the Fe-P-O plating layer is not particularly limited, but as a feasible value, it is the total amount of Fe, P, O per one side of the steel sheet.
It is preferably 0.1 to 10 g / m 2 from the viewpoint of performance and cost. In the present invention, Ni, Cu, Co, Cr, Mn, Mg, C, B, in the plating layer of the Fe-PO plating layer,
At least one element selected from the group consisting of N, Al, Si, Ca, Ti, Nb, Mo, Sn, Sb and Bi may be contained.
【００２２】本発明におけるFe−Ｐ−Ｏめっき層を形成
する方法としては、好ましくは、以下の実施例で示すよ
うに、Feイオンを含有し、Ｐおよび酸素の供給源になる
次亜燐酸ナトリウムなどの燐酸系化合物を添加した硫酸
浴、塩化浴から電気めっきによりめっき層を形成する方
法が例示される。Feイオンの供給源としては、FeSO4 、
FeCl2 、FeCl3 、Fe2(SO4)3 などから選ばれる１種また
は２種以上が例示されるが特に限定されるものではな
い。As a method of forming the Fe-P-O plating layer in the present invention, preferably sodium hypophosphite containing Fe ions and serving as a source of P and oxygen, as shown in the following examples. Examples of the method include forming a plating layer by electroplating from a sulfuric acid bath or a chloride bath to which a phosphoric acid compound such as the above is added. As a source of Fe ions, FeSO 4 ,
One or more selected from FeCl 2 , FeCl 3 , Fe 2 (SO 4 ) 3 and the like are exemplified, but not particularly limited.
【００２３】燐酸系化合物としては、好ましくはNa、K
などアルカリ金属の燐酸塩、亜燐酸塩および次亜燐酸塩
などから選ばれる１種または２種以上を挙げることがで
きる。これらの燐酸系化合物をめっき浴へ添加すること
により、めっき層へＰおよび酸素を含有せしめることが
可能であるが、さらに積極的に酸素をめっき層へ含有さ
せる場合は、めっき浴中のＦｅイオンを錯化させるのに
有効なNa、K などアルカリ金属のクエン酸塩などから選
ばれる１種または２種以上をめっき浴中へ添加すればよ
い。The phosphoric acid compound is preferably Na or K.
One or more selected from alkali metal phosphates, phosphites, hypophosphites, and the like. It is possible to add P and oxygen to the plating layer by adding these phosphoric acid compounds to the plating bath. However, when oxygen is more positively added to the plating layer, Fe ions in the plating bath are added. One or more selected from alkali metal citrates such as Na and K which are effective for complexing the above may be added to the plating bath.
【００２４】前記Fe−Ｐ−Ｏめっきにおけるめっき浴中
のFeイオンの濃度は、Feとして 0.1〜2.0 モル／ｌ、ア
ルカリ金属の燐酸塩、亜燐酸塩、次亜燐酸塩など燐酸系
化合物の濃度は、0.0001〜1.0 モル／ｌ、より好ましく
は 0.001〜1.0 モル／ｌであることが好ましい。また、
アルカリ金属のクエン酸塩の濃度は、0.01〜1.0 モル／
ｌであることが好ましい。The concentration of Fe ions in the plating bath in the Fe-PO plating is 0.1 to 2.0 mol / l of Fe, and the concentration of a phosphoric acid compound such as an alkali metal phosphate, phosphite or hypophosphite. Is preferably 0.0001 to 1.0 mol / l, more preferably 0.001 to 1.0 mol / l. Also,
The concentration of alkali metal citrate is 0.01-1.0 mol /
It is preferably l.
【００２５】また、第２の発明および第４の発明におけ
る亜鉛系めっき層のめっきの種類としては、純Znめっ
き、Zn−Ni合金めっき、Zn−Fe合金めっき、Zn−Cr合金
めっき、Zn−Co合金めっきなどの二元系Zn合金めっき、
Zn−Ni−Cr合金めっき、Zn−Co−Cr合金めっきなどの三
元系Zn合金めっきなどを用いることができ、またZn−Si
O2めっき、Zn−Co−Cr−Al2O3 めっきなどの亜鉛系複合
分散めっきも用いることができる。The types of plating of the zinc-based plating layer in the second and fourth inventions include pure Zn plating, Zn-Ni alloy plating, Zn-Fe alloy plating, Zn-Cr alloy plating, Zn- Binary Zn alloy plating such as Co alloy plating,
It is possible to use ternary Zn alloy plating such as Zn-Ni-Cr alloy plating and Zn-Co-Cr alloy plating.
Zinc-based composite dispersion plating such as O 2 plating and Zn-Co-Cr-Al 2 O 3 plating can also be used.
【００２６】なお、本発明における亜鉛系複合分散めっ
きとは、亜鉛めっきまたは亜鉛系合金めっきに、シリ
カ、アルミナなどの酸化物無機粒子および／または有機
樹脂を分散共析せしめた複合めっきを示す。これらの亜
鉛系めっきは、電気めっき法、溶融めっき法、合金化溶
融めっき法あるいは気相めっき法によって施される。The zinc-based composite dispersion plating in the present invention refers to a composite plating in which inorganic oxide particles such as silica and alumina and / or organic resin are co-deposited on zinc plating or zinc alloy plating. These zinc-based platings are performed by electroplating, hot dipping, alloying hot dipping, or vapor plating.
【００２７】本発明における亜鉛系めっき層のめっき付
着量としては、電気めっき法の場合は、鋼板片面当た
り、好ましくは５〜60g/m2、より好ましくは５〜15g/
m2、溶融めっき法、合金化溶融めっき法の場合は、鋼板
片面当たり、好ましくは10〜150g/m2、より好ましくは1
0〜30g/m2、気相めっき法の場合は、鋼板片面当たり、
好ましくは５〜60g/m2、より好ましくは５〜15g/m2であ
ることが好ましい。In the case of the electroplating method, the coating amount of the zinc-based plating layer in the present invention is preferably 5 to 60 g / m 2 , more preferably 5 to 15 g / m 2 per one side of the steel sheet.
m 2 , hot dipping method, in the case of alloying hot dipping method, preferably 10 to 150 g / m 2 , more preferably 1 per one side of the steel sheet.
0 to 30 g / m 2 , in the case of vapor phase plating, per side of steel plate,
It is preferably 5 to 60 g / m 2 , and more preferably 5 to 15 g / m 2 .
【００２８】これは、亜鉛系めっき層のめっき付着量が
前記各々のめっきに対する好ましい下限値未満の場合は
耐食性が低下し、好ましい上限値を超えた場合はスポッ
ト溶接性が低下し、経済性も劣るためである。これら電
気亜鉛系めっき、溶融亜鉛系めっきなど亜鉛系めっきを
Fe−Ｐ−Ｏめっき層の上に施す場合のめっき密着性は、
先に述べたとおり、Fe−Ｐ−Ｏめっき層中の酸素量を前
記好適範囲に規定すれば実際に問題ない。This is because when the coating amount of the zinc-based plating layer is less than the preferable lower limit value for each of the above-mentioned plating, the corrosion resistance is lowered, and when it exceeds the preferable upper limit value, the spot weldability is lowered and the economical efficiency is also increased. Because it is inferior. Zinc-based plating such as electric zinc-based plating and hot-dip zinc-based plating
The plating adhesion when applied on the Fe-PO plating layer is
As described above, if the oxygen amount in the Fe—P—O plating layer is defined within the above-mentioned preferable range, there will be no practical problem.
【００２９】[0029]
【実施例】以下に本発明を実施例に基づき具体的に説明
する。冷延鋼板（ＳＰＣＤ）をアルカリ脱脂し、５％塩
酸で酸洗した後、水洗し、表１に示す条件でFe−Ｐ−Ｏ
めっきを施した（実施例１〜10）。得られたFe−Ｐ−Ｏ
めっき層のめっき付着量、Ｐ含有率、酸素含有率を表２
に示す。EXAMPLES The present invention will be specifically described below based on examples. Cold-rolled steel sheet (SPCD) was degreased with alkali, pickled with 5% hydrochloric acid, washed with water, and Fe-PO under the conditions shown in Table 1.
It was plated (Examples 1-10). Obtained Fe-PO
Table 2 shows the coating weight, P content, and oxygen content of the plating layer.
Shown in
【００３０】次に、実施例３〜10の鋼板に関しては、こ
れらのFe−Ｐ−Ｏめっきの後に、一方、比較例１〜５の
鋼板に関しては、冷延鋼板（ＳＰＣＤ）のままでアルカ
リ脱脂、酸洗を施した後に、それぞれ下記に示す亜鉛系
めっきを施した。 （実施例３および実施例７、比較例１）実験室的に竪型
の溶融亜鉛めっき装置にて、焼鈍後、溶融亜鉛めっきを
施し、これを赤外加熱炉で合金化処理し付着量20ｇ／ｍ
2 の合金化溶融亜鉛めっき鋼板を得た。 （実施例４および実施例８、比較例２）流動セルにて実
験室的に付着量５ｇ／ｍ2 のZn−Ni合金めっきを施し
た。 （実施例５および実施例９、比較例３）流動セルにて実
験室的に付着量10ｇ／ｍ2 の電気亜鉛めっきを施した。 （実施例６および実施例10、比較例４）実験室的に竪型
の溶融亜鉛めっき装置にて、焼鈍後、付着量25ｇ／ｍ2
の溶融亜鉛めっきを施した。 （比較例５）実験室的に竪型の溶融亜鉛めっき装置に
て、焼鈍後、溶融亜鉛めっきを施し、これを赤外加熱炉
で合金化処理し付着量60ｇ／ｍ2 の合金化溶融亜鉛めっ
き鋼板を得た。 （比較例６） 冷延鋼板（ＳＰＣＤ） 板厚 0.8mm 以上で得られた下記および表２に示す供試材に対して、
下記に示す性能試験を行った。試験結果を、表２に併せ
て示す。Next, with respect to the steel sheets of Examples 3 to 10, after these Fe—P—O plating, on the other hand, with respect to the steel sheets of Comparative Examples 1 to 5, the cold rolled steel sheet (SPCD) was used as it was for alkaline degreasing. After the pickling, the zinc-based plating shown below was applied. (Examples 3 and 7 and Comparative Example 1) In a laboratory vertical type hot-dip galvanizing device, hot-dip galvanizing was performed after annealing, and this was alloyed in an infrared heating furnace to deposit 20 g. / M
The alloyed hot-dip galvanized steel sheet of No. 2 was obtained. (Examples 4 and 8 and Comparative Example 2) Zn-Ni alloy plating with a deposition amount of 5 g / m 2 was applied in a laboratory in a flow cell. (Examples 5 and 9 and Comparative Example 3) Electrogalvanization with a deposition amount of 10 g / m 2 was performed in a laboratory in a fluidized cell. (Examples 6 and 10 and Comparative Example 4) After being annealed in a laboratory vertical hot dip galvanizing apparatus, an adhesion amount of 25 g / m 2
Hot-dip galvanized. (Comparative Example 5) In a laboratory vertical type hot-dip galvanizing apparatus, after hot-dip galvanizing, hot-dip galvanizing was performed, and this was alloyed in an infrared heating furnace to give an alloyed hot-dip zinc with an adhesion amount of 60 g / m 2. A plated steel sheet was obtained. (Comparative Example 6) Cold rolled steel plate (SPCD) With respect to the test materials shown below and in Table 2 obtained with a plate thickness of 0.8 mm or more,
The performance test shown below was performed. The test results are also shown in Table 2.
【００３１】実施例１、２：Fe−Ｐ−Ｏめっき鋼板 実施例３〜10：（Fe−Ｐ−Ｏめっき＋亜鉛系めっき）鋼
板 比較例１〜５：亜鉛系めっき鋼板 比較例６ ：冷延鋼板（ＳＰＣＤ） （未塗装耐食性：）未塗装の供試材に対して、以下に示
すサイクルの複合腐食試験を行った。Examples 1 and 2: Fe-P-O plated steel sheet Examples 3 to 10: (Fe-P-O plating + zinc-based plating) steel sheet Comparative examples 1 to 5: Zinc-based plated steel sheet Comparative example 6: Cold Rolled steel plate (SPCD) (Unpainted corrosion resistance :) An unpainted sample material was subjected to a complex corrosion test in the cycle shown below.
【００３２】耐食性は、 100サイクル後の冷延鋼板自体
の平均板厚減少量で評価した。35℃で５％NaCl溶液を
６時間噴霧→60℃にて２時間乾燥→50℃、95％ＲＨ
（湿潤）雰囲気下に保持→60℃にて２時間乾燥→50
℃、95％ＲＨ（湿潤）雰囲気下に保持→60℃にて２時
間乾燥→ （塗装後耐食性：）リン酸亜鉛化成処理｛日本パーカラ
イジング社製、パルボンド＃3020（商品名）｝を施した
のち、カチオン電着塗装｛日本ペイント社製、Ｕ− 600
（商品名）；20μｍ｝を施した試料について、素地鋼板
に達するまでのクロスカットを入れ、前記の条件でサイ
クル腐食試験を行い、耐食性を評価した。耐食性は、 1
00サイクル後の片側ブリスター幅で評価した。The corrosion resistance was evaluated by the reduction amount of the average sheet thickness of the cold rolled steel sheet itself after 100 cycles. Spray 5% NaCl solution at 35 ℃ for 6 hours → dry at 60 ℃ for 2 hours → 50 ℃, 95% RH
Keep in (wet) atmosphere → Dry at 60 ℃ for 2 hours → 50
℃, keep in 95% RH (wet) atmosphere → dry at 60 ℃ for 2 hours → (corrosion resistance after painting :) zinc phosphate chemical conversion treatment (Nippon Parkerizing Co., Ltd., Palbond # 3020 (trade name)) , Cationic electrodeposition coating {Nippon Paint Co., U-600
(Product name); 20 μm} was subjected to a cross-cut until reaching the base steel sheet, and a cycle corrosion test was performed under the above conditions to evaluate the corrosion resistance. Corrosion resistance is 1
The blister width on one side after 00 cycles was evaluated.
【００３３】（スポット溶接性：）以下の条件でスポッ
ト溶接を行い、連続打点性を調査した。連続打点性は、
ナゲット径が、鋼板の板厚をｔとして４√ｔ以下になっ
た時の打点数で評価した。 電極加圧力 200kgf 初期加圧時間 30サイクル 通電時間 10サイクル 保持時間 10サイクル 開放時間 50サイクル 溶接電流 初期ナゲットが５mmとなる電流 電極材質 アルミナ分散銅 （めっき性：）表２に示した亜鉛系めっきを施した時の
不めっきの発生状況を調査した。不めっきが全く発生し
なかったものを○、少しでも不めっきが発生したものを
△、使用不可能なもの（：不めっき面積率が５％以上の
もの）を×とした。(Spot Weldability :) Spot welding was carried out under the following conditions to investigate the continuous spotting property. Continuous dot performance is
The nugget diameter was evaluated by the number of dots when the thickness of the steel plate was 4√t or less, where t was the plate thickness. Electrode pressure 200kgf Initial pressurization time 30 cycles Energization time 10 cycles Hold time 10 cycles Open time 50 cycles Welding current Current when initial nugget is 5mm Electrode material Alumina-dispersed copper (platability :) The zinc-based plating shown in Table 2 The occurrence of non-plating when applied was investigated. The case where no non-plating occurred at all was evaluated as ◯, the case where even a little non-plating occurred was evaluated as Δ, and the unusable one (: non-plating area ratio of 5% or more) was evaluated as x.
【００３４】[0034]
【表１】 [Table 1]
【００３５】[0035]
【表２】 [Table 2]
【００３６】表１から本発明のFe−Ｐ−Ｏめっき鋼板
は、従来の冷延鋼板に比較し大幅に耐食性が向上し、さ
らに該鋼板に亜鉛系めっきを施した鋼板は、亜鉛系めっ
き層との相乗効果により、さらに耐食性が向上し、従来
の合金化溶融亜鉛めっき鋼板と同等の耐食性を発現させ
るために必要なめっき層の亜鉛付着量を大幅に低減させ
ることが可能となり、スポット溶接性が改善されている
ことが判る。From Table 1, the Fe—P—O plated steel sheet of the present invention has significantly improved corrosion resistance as compared with the conventional cold-rolled steel sheet, and the steel sheet obtained by subjecting the steel sheet to zinc-based plating has a zinc-based plating layer. With the synergistic effect with, the corrosion resistance is further improved, and it becomes possible to significantly reduce the zinc adhesion amount of the plating layer required to develop the corrosion resistance equivalent to that of the conventional galvannealed steel sheet. It can be seen that is improved.
【００３７】[0037]
【発明の効果】本発明により、従来の冷延鋼板と同等の
スポット溶接性を有し、かつ自動車用として充分な耐食
性を有するめっき鋼板が得られた。さらに、従来の亜鉛
系めっき鋼板は、自動車用として十分な耐食性を得るた
めの必要めっき付着量の点から冷延鋼板に比べ溶接性が
悪く、またコスト面での改善も望まれていたが、本発明
により、高耐食性を確保したまま亜鉛系めっきの付着量
を低減させることが可能となったため、溶接性が著しく
改善され、さらに製造コストも低廉なものになった。According to the present invention, a plated steel sheet having spot weldability equivalent to that of a conventional cold-rolled steel sheet and having sufficient corrosion resistance for automobiles was obtained. Further, the conventional zinc-based plated steel sheet has poor weldability as compared with the cold-rolled steel sheet in terms of the amount of coating required to obtain sufficient corrosion resistance for automobiles, and improvement in cost has also been desired, According to the present invention, it is possible to reduce the amount of zinc-based plating adhered while ensuring high corrosion resistance, so that the weldability is remarkably improved and the manufacturing cost is also reduced.
Claims (6)
ことを特徴とする耐食性に優れためっき鋼板。1. A plated steel sheet having excellent corrosion resistance, which has a Fe—P—O plating layer on the surface of the steel sheet.
−Ｏめっき層を有することを特徴とする耐食性に優れた
めっき鋼板。2. Fe-P at the interface between the zinc-based plating layer and the steel sheet.
-A plated steel sheet having excellent corrosion resistance, which has an O plating layer.
01〜10wt％、酸素含有率が 0.001〜10wt％であることを
特徴とする請求項１または２記載の耐食性に優れためっ
き鋼板。3. The Fe content in the Fe—P—O plating layer is 0.0.
The plated steel sheet having excellent corrosion resistance according to claim 1 or 2, wherein the plated steel sheet has an oxygen content of 01 to 10 wt% and an oxygen content of 0.001 to 10 wt%.
板片面当り 0.1〜10ｇ／ｍ2 であることを特徴とする請
求項１〜３いずれかに記載の耐食性に優れためっき鋼
板。4. The plated steel sheet having excellent corrosion resistance according to claim 1, wherein the amount of the Fe—P—O plating layer deposited on the steel sheet is 0.1 to 10 g / m 2 per side.
化合物を含有するめっき浴中で電気めっきし、鋼板表面
にFe−Ｐ−Ｏめっき層を形成することを特徴とする耐食
性に優れためっき鋼板の製造方法。5. A steel sheet is electroplated in a plating bath containing Fe ions and a phosphoric acid compound to form a Fe—P—O plating layer on the surface of the steel sheet, which is excellent in corrosion resistance. Manufacturing method of plated steel sheet.
化合物を含有するめっき浴中で電気めっきし、鋼板表面
にFe−Ｐ−Ｏめっき層を形成した後、該めっき層上に亜
鉛系めっき層を形成することを特徴とする耐食性に優れ
ためっき鋼板の製造方法。6. A steel sheet is electroplated in a plating bath containing Fe ions and a phosphoric acid compound to form a Fe—P—O plating layer on the surface of the steel sheet, and then a zinc-based plating layer is formed on the plating layer. A method for producing a plated steel sheet having excellent corrosion resistance, which comprises forming a plated layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7340594A JPH08269780A (en) | 1995-02-01 | 1995-12-27 | Plated steel sheet with excellent corrosion resistance and method for producing the same |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7-15090 | 1995-02-01 | ||
| JP1509095 | 1995-02-01 | ||
| JP7340594A JPH08269780A (en) | 1995-02-01 | 1995-12-27 | Plated steel sheet with excellent corrosion resistance and method for producing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08269780A true JPH08269780A (en) | 1996-10-15 |
Family
ID=26351182
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7340594A Pending JPH08269780A (en) | 1995-02-01 | 1995-12-27 | Plated steel sheet with excellent corrosion resistance and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08269780A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022244782A1 (en) * | 2021-05-17 | 2022-11-24 | Ｊｆｅスチール株式会社 | Stock cold-rolled steel sheet with fe-based coating film, method for producing stock cold-rolled steel sheet with fe-based coating film, method for producing cold-rolled steel sheet with fe-based coating film, method for producing hot-dipped galvanized steel sheet, and method for producing alloyed hot-dipped galvanized steel sheet |
-
1995
- 1995-12-27 JP JP7340594A patent/JPH08269780A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022244782A1 (en) * | 2021-05-17 | 2022-11-24 | Ｊｆｅスチール株式会社 | Stock cold-rolled steel sheet with fe-based coating film, method for producing stock cold-rolled steel sheet with fe-based coating film, method for producing cold-rolled steel sheet with fe-based coating film, method for producing hot-dipped galvanized steel sheet, and method for producing alloyed hot-dipped galvanized steel sheet |
| JPWO2022244782A1 (en) * | 2021-05-17 | 2022-11-24 |
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