JPH0665759A - Double-layer electroplated steel sheet having high corrosion resistance - Google Patents
Double-layer electroplated steel sheet having high corrosion resistanceInfo
- Publication number
- JPH0665759A JPH0665759A JP22311392A JP22311392A JPH0665759A JP H0665759 A JPH0665759 A JP H0665759A JP 22311392 A JP22311392 A JP 22311392A JP 22311392 A JP22311392 A JP 22311392A JP H0665759 A JPH0665759 A JP H0665759A
- Authority
- JP
- Japan
- Prior art keywords
- plating layer
- layer
- corrosion resistance
- plating
- steel sheet
- 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.)
- Granted
Links
Landscapes
- Electroplating Methods And Accessories (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は優れた塗装後の耐衝撃密
着性と耐食性を有し、種々の用途例えば自動車用防錆鋼
板として適用できる高耐食性複層電気めっき鋼板に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high corrosion resistant multi-layer electroplated steel sheet having excellent impact resistance and corrosion resistance after coating and applicable to various applications such as an anticorrosion steel sheet for automobiles.
【０００２】[0002]
【従来の技術】亜鉛めっき鋼板が耐食性向上方法として
は、亜鉛のめっき量（付着量）を増加させるという手段
があるが、これは溶接性や加工性の点で問題が多い。そ
こで亜鉛自身の溶解を抑制し亜鉛めっきの寿命を延ばす
方法として、多くの合金めっきが提案されている。中で
もＦｅ、Ｃｏ、Ｎｉといった鉄族金属を合金成分として
含有するＺｎ系合金めっきは、その良好な耐食性が認め
られ、実用化されている。また、さらに耐食性を向上さ
せる目的で、Ｃｒを含有させる試みもなされ、例えば特
開昭６１−２７０３９８号公報、特開昭６２−５４０９
９号公報などが開示されているが、Ｃｒ含有率は５％以
下と低く、耐食性において従来のＺｎ系合金めっきを凌
駕するには到らず、より高耐食性のめっき鋼板が望まれ
ている。2. Description of the Related Art As a method of improving the corrosion resistance of galvanized steel sheets, there is a means of increasing the zinc coating amount (adhesion amount), but this has many problems in terms of weldability and workability. Therefore, many alloy platings have been proposed as a method of suppressing the dissolution of zinc itself and extending the life of zinc plating. Above all, Zn-based alloy plating containing an iron group metal such as Fe, Co, or Ni as an alloy component has been recognized for its good corrosion resistance and has been put to practical use. Further, for the purpose of further improving the corrosion resistance, attempts have been made to add Cr, for example, JP-A-61-270398 and JP-A-65-24094.
No. 9 gazette is disclosed, the Cr content is as low as 5% or less, and the corrosion resistance does not exceed that of the conventional Zn-based alloy plating, and a plated steel sheet having higher corrosion resistance is desired.
【０００３】一方、これらＺｎ系合金めっきはめっき層
の持つ内部応力がＺｎめっきよりも高く、そのため鋼板
に対するめっき密着性が本質的にＺｎめっきに比較する
と弱い。自動車車体外面に適用した場合には、通常３コ
ート塗装が合計１００μ以上の厚みで施され、これらの
焼き付け時の収縮応力がめっき層に作用して、めっき密
着性は塗装前よりさらに低い状態になる。また、冬期の
寒冷地では氷点以下に気温が低下し、この影響で塗膜の
収縮が進むため、めっき層に作用する応力もさらに大き
くなり、めっき密着性は一段と低い状態になる。このよ
うな過酷な条件下で、走行中の自動車に小石や散布岩塩
が衝突する（この現象をチッピングと称する）と、その
衝撃力でめっき層が剥離する、という問題を生じる。こ
のような問題に対しては、特開昭５９−２００７８９号
公報の如く鋼板上に特定の金属からなる析出物を分散付
着させた後Ｚｎ系合金めっきを施す方法、Ｚｎ−Ｎｉ合
金めっきについては特開平１−２２５７９０号公報の如
く下層にＮｉ含有率の低いＺｎ−Ｎｉ合金めっきを施す
方法などが開示されている。しかし、いずれの方法も、
塗装後の低温下でのチッピングという過酷な条件下での
めっき密着性は、十分なレベルまでには改善されない。On the other hand, in these Zn-based alloy platings, the internal stress of the plating layer is higher than that of the Zn plating, and therefore the adhesion to the steel sheet is essentially weaker than that of the Zn plating. When applied to the outer surface of an automobile body, usually 3 coats of coating are applied with a total thickness of 100μ or more, and the shrinkage stress at the time of baking acts on the plating layer, and the plating adhesion becomes even lower than before coating. Become. Further, in cold regions in winter, the temperature drops below the freezing point, and the shrinkage of the coating film progresses due to this effect, so the stress acting on the plating layer becomes even greater, and the plating adhesion becomes even lower. Under such severe conditions, when pebbles or sprayed rock salt collides with a running vehicle (this phenomenon is called chipping), the impact force causes the plating layer to peel off. To solve such a problem, as described in Japanese Patent Laid-Open No. 59-200789, a method of depositing a deposit made of a specific metal on a steel sheet and then performing Zn-based alloy plating, and Zn-Ni alloy plating are described below. JP-A-1-225790 discloses a method of plating a lower layer with a Zn-Ni alloy having a low Ni content. However, both methods
The adhesion of plating under the severe condition of chipping at low temperature after coating is not improved to a sufficient level.
【０００４】[0004]
【発明が解決しようとする課題】本発明者らは、特定の
有機高分子をＣｒ析出促進剤としてめっき浴に添加する
ことにより、従来にない高含有率のＣｒと微量の有機高
分子を含み、画期的な耐食性を有するＺｎ系電気めっき
鋼板を得る目処を得た。しかしながら、この新規のＺｎ
系電気めっきも従来のＺｎ系合金めっきと同様に過酷な
条件下でのめっき剥離は回避できず、これを解決する必
要があった。また、Ｚｎ系合金めっきの密着性を向上さ
せる目的で開示されている前記の方法を適用しても、不
十分であり、該Ｚｎ系電気めっきに適した手段を見出す
必要があった。本発明はかかる事情に鑑み、塗装後の耐
衝撃性に優れた複層電気めっき鋼板を提供するものであ
る。The present inventors have added a specific organic polymer as a Cr deposition accelerator to a plating bath so that a high content of Cr and a trace amount of the organic polymer, which have never existed before, are contained. Thus, a prospect for obtaining a Zn-based electroplated steel sheet having epoch-making corrosion resistance was obtained. However, this new Zn
Similar to conventional Zn-based alloy plating, system-based electroplating cannot avoid stripping of the plating under severe conditions, and it is necessary to solve this problem. Further, even if the above-mentioned method disclosed for the purpose of improving the adhesiveness of Zn-based alloy plating is applied, it is insufficient, and it is necessary to find a means suitable for the Zn-based electroplating. In view of such circumstances, the present invention provides a multi-layer electroplated steel sheet having excellent impact resistance after coating.
【０００５】[0005]
【課題を解決するための手段】本発明の要旨は、以下の
通りである。 （１）鋼板表面に、第１めっき層として付着量０．０１
〜２ｇ／ｍ2のＺｎめっき層が形成され、この上に第２
めっき層としてＣｒを５〜３０重量％、Ｆｅ、Ｃｏ、Ｎ
ｉのうち１種もしくは２種以上を０．１〜１０重量％、
有機高分子を０．００１〜５重量％含有するＺｎ系複合
電気めっき層が形成されたことを特徴とする高耐食性複
層電気めっき鋼板。 （２）第２めっき層の上に、第３めっき層として付着量
０．１〜５ｇ／ｍ2のＺｎもしくはＺｎ系合金めっき層
が形成された（１）の高耐食性複層電気めっき鋼板。 （３）第２めっき層に含有される有機高分子が、カチオ
ンポリマーである（１）、（２）の高耐食性複層電気め
っき鋼板。The gist of the present invention is as follows. (1) Amount of adhesion of 0.01 as the first plating layer on the surface of the steel plate
~ 2g / m 2 of Zn plating layer is formed, and the second
5-30% by weight of Cr as a plating layer, Fe, Co, N
0.1 to 10% by weight of one or more of i,
A high corrosion-resistant multi-layer electroplated steel sheet, wherein a Zn-based composite electroplated layer containing 0.001 to 5% by weight of an organic polymer is formed. (2) The high corrosion-resistant multi-layer electroplated steel sheet according to (1), wherein a Zn or Zn-based alloy plating layer having an adhesion amount of 0.1 to 5 g / m 2 is formed as a third plating layer on the second plating layer. (3) The high corrosion-resistant multi-layer electroplated steel sheet according to (1) or (2), wherein the organic polymer contained in the second plating layer is a cationic polymer.
【０００６】[0006]
【作用】本発明の複層電気めっき鋼板は２層ないし３層
のめっき層から構成される。すなわち、第１めっき層は
付着量０．０１〜２ｇ／ｍ2のＺｎめっき層であり、第
２めっき層の耐衝撃密着性を著しく向上させる。第２め
っき層はＣｒを５〜３０重量％、Ｆｅ、Ｃｏ、Ｎｉのう
ち１種もしくは２種以上を０．１〜１０重量％、有機高
分子を０．００１〜５重量％含有するＺｎ系複合電気め
っき層であり、優れた耐食性を発揮する。第３めっき層
は必要に応じてなされる付着量０．１〜５ｇ／ｍ2のＺ
ｎもしくはＺｎ系合金めっき層であり塗装後耐食性を向
上させる。The multi-layer electroplated steel sheet of the present invention comprises two to three plating layers. That is, the first plating layer is a Zn plating layer having an adhesion amount of 0.01 to 2 g / m 2 , and significantly improves the impact resistance adhesion of the second plating layer. The second plating layer contains 5 to 30 wt% of Cr, 0.1 to 10 wt% of one or more of Fe, Co and Ni, and 0.001 to 5 wt% of organic polymer. It is a composite electroplated layer and exhibits excellent corrosion resistance. The third plating layer is made of Z having an adhesion amount of 0.1 to 5 g / m 2 as necessary.
It is an n- or Zn-based alloy plating layer and improves the corrosion resistance after coating.
【０００７】まず、第１めっき層について説明する。従
来のＺｎ系合金めっきや本発明で対象とするＺｎ系複合
電気めっきは、単純なＺｎめっきに比べて内部応力が高
く、すなわち、めっき層が硬く、塑性変形しにくい。故
に、チッピングなどの衝撃を受けると、衝撃力を吸収で
きず、衝撃力は地鉄との界面に達し、めっき層を地鉄界
面から剥離させてしまう。しかるに、第１めっき層とし
て、単純なＺｎめっき層を設けることにより、耐衝撃密
着性は大幅に向上する。Ｚｎめっきは軟らかいためチッ
ピングなどの衝撃を受けても塑性変形して衝撃力を吸収
し、かつ地鉄および第２めっき層との密着性も強固であ
るため、過酷な条件下でも容易にめっき剥離を生じせし
めない。第１めっき層としてのＺｎ付着量は０．０１〜
２ｇ／ｍ 2が好ましい。０．０１ｇ／ｍ2未満では効果的
な耐衝撃密着性の改善は図り得ない。また２ｇ／ｍ2を
超えると腐食環境下でＺｎとしての性質が強く出てくる
ため、第２めっき層の耐食性を阻害するので好ましくな
い。耐衝撃密着性および耐食性の観点からは０．０５〜
１ｇ／ｍ2の範囲がより好ましい。First, the first plating layer will be described. Servant
Conventional Zn-based alloy plating and Zn-based composite that is the subject of the present invention
Electroplating has higher internal stress than simple Zn plating.
That is, the plating layer is hard and is not easily plastically deformed. late
In addition, when it receives a shock such as chipping, it can absorb the shock force.
The flaws and the impact force reach the interface with the base steel, and the plating layer
It peels off the surface. However, as the first plating layer
By providing a simple Zn plating layer,
Wearability is greatly improved. Zn plating is soft
Absorbs impact force by plastically deforming even when it receives a shock such as a ping
In addition, the adhesion to the base metal and the second plating layer is also strong.
Therefore, it is possible to easily cause plating peeling even under severe conditions.
I don't. The amount of Zn deposited as the first plating layer is 0.01 to
2 g / m 2Is preferred. 0.01 g / m2Less than is effective
The impact resistance cannot be improved. 2g / m2To
If it exceeds, the property as Zn will come out strongly in the corrosive environment.
Therefore, the corrosion resistance of the second plating layer is impaired, which is not preferable.
Yes. From the viewpoint of impact resistance and corrosion resistance, 0.05-
1 g / m2Is more preferable.
【０００８】第２めっき層は、高度の耐食性を有し、本
発明の複層電気めっき鋼板の主層である。第２めっき層
中のＣｒ含有率は５〜３０重量％が好ましい。５重量％
未満では耐食性向上効果は認められるものの、赤錆が発
生しやすい傾向は残り、耐食性は十分ではない。５重量
％以上で赤錆発生は極端に抑制され、めっきままの裸の
状態で塩水噴霧試験を５００時間以上行なっても容易に
赤錆は発生しなくなり、Ｚｎ−Ｎｉ、Ｚｎ−Ｆｅなど従
来公知の合金めっきを凌ぐ高耐食性を発揮する。Ｃｒの
含有により、腐食生成物が難溶性の保護皮膜を形成して
表面を覆い腐食の進行を抑制することが、高耐食性を発
揮する理由であろうと推定される。Ｃｒ含有率は３０重
量％を超えても高度の耐食性を有するが、後述するカチ
オンポリマーなどＣｒ析出を促進する有機高分子の共析
効果をもってしても、加工時のパウダリング性の劣化を
防止しえず、実用上は適用が難しい。The second plating layer has a high degree of corrosion resistance and is the main layer of the multi-layer electroplated steel sheet of the present invention. The Cr content in the second plating layer is preferably 5 to 30% by weight. 5% by weight
If the amount is less than the above, the effect of improving the corrosion resistance is recognized, but the tendency that red rust easily occurs remains, and the corrosion resistance is insufficient. When the content is 5% by weight or more, the generation of red rust is extremely suppressed, and red rust does not easily occur even if a salt spray test is conducted for 500 hours or more in a bare state as it is, and conventionally known alloys such as Zn-Ni and Zn-Fe. Exhibits high corrosion resistance superior to plating. It is presumed that the inclusion of Cr may be the reason why high corrosion resistance is exerted because the corrosion product forms a hardly soluble protective film to cover the surface and suppress the progress of corrosion. Even if the Cr content exceeds 30% by weight, it has a high degree of corrosion resistance, but even if it has the eutectoid effect of an organic polymer that promotes Cr precipitation such as the cationic polymer described later, it prevents deterioration of the powdering property during processing. It is difficult to apply in practice.
【０００９】第２めっき層には、金属成分としてさらに
Ｆｅ、Ｃｏ、Ｎｉといった鉄族金属を含む。鉄族金属の
作用は、Ｃｒとの相互作用により腐食生成物の安定性を
さらに高め、耐食性を向上させる点にある。これらの含
有率は１種もしくは２種以上の総量で０．１〜１０重量
％が好ましい。０．１重量％未満では上記効果が顕著で
なく、１０重量％を超えると鉄族金属の性質が強くなり
Ｃｒの効果が低減する結果、耐食性低下の傾向が現われ
る。加工時の耐パウダリング性をも考慮すると、Ｃｒ及
び鉄族金属の総量は３０重量％以下が好ましい。なお、
鉄族金属の中でもＮｉは耐食性に対しても効果的であ
り、最も有利である。The second plating layer further contains an iron group metal such as Fe, Co and Ni as a metal component. The function of the iron group metal is to further improve the stability of the corrosion product and improve the corrosion resistance by the interaction with Cr. The content of these is preferably 0.1 to 10% by weight in total of one kind or two or more kinds. If it is less than 0.1% by weight, the above effect is not remarkable, and if it exceeds 10% by weight, the properties of the iron group metal are strengthened and the effect of Cr is reduced, so that the corrosion resistance tends to decrease. Considering the powdering resistance during processing, the total amount of Cr and iron group metal is preferably 30% by weight or less. In addition,
Among the iron group metals, Ni is also effective for corrosion resistance and is most advantageous.
【００１０】第２めっき層中に含有される有機高分子
は、Ｃｒ析出促進剤としてめっき浴中に添加されるもの
であり、Ｃｒ3+イオンを金属Ｃｒとして析出させる作用
を持つ。これをＣｒとともにめっき層中に共析させるこ
とにより、加工時の耐パウダリング性を向上させること
ができる。このような有機高分子の共析効果は、Ｃｒが
Ｚｎの均一な電析成長を阻害し、均一性、平滑性に欠け
ためっき構造になることを防止する点にあると推定され
る。即ち、共析する有機高分子を介することによって、
ＺｎとＣｒが均一に混合もしくは合金化した緻密なめっ
き層が形成されると考えられる。有機高分子の含有率は
０．００１〜５重量％が好ましい。０．００１重量％未
満では、耐パウダリング性向上効果が乏しく、５重量％
超の含有率はめっき浴中の有機高分子濃度を増しても得
られ難いのみならず、多量に共析すると返ってめっき密
着性が低下する。耐パウダリング性を確実なものとする
ためには、Ｃｒ含有率の１／１０００以上の含有率で有
機高分子を共析させることが望ましい。有機高分子とし
ては、水溶性のカチオンポリマーが効果的であり、中で
も次に示す４級アミンの塩を主鎖に含む分子量１０3〜
１０6のポリマーが効果的である。The organic polymer contained in the second plating layer is added to the plating bath as a Cr deposition accelerator and has a function of depositing Cr 3+ ions as metallic Cr. By co-depositing this together with Cr in the plating layer, the powdering resistance during processing can be improved. It is presumed that such an eutectoid effect of the organic polymer lies in the fact that Cr hinders the uniform electrodeposition growth of Zn and prevents the plating structure from lacking uniformity and smoothness. That is, through the co-deposited organic polymer,
It is considered that a dense plating layer in which Zn and Cr are uniformly mixed or alloyed is formed. The content of the organic polymer is preferably 0.001 to 5% by weight. If it is less than 0.001% by weight, the effect of improving the powdering resistance is poor, and it is 5% by weight.
Not only is it difficult to obtain a content higher than the above even if the concentration of the organic polymer in the plating bath is increased, but when a large amount of eutectoid is returned, the plating adhesion is lowered. In order to secure the powdering resistance, it is desirable to co-deposit the organic polymer in a Cr content of 1/1000 or more. As the organic polymer, a water-soluble cationic polymer is effective, and among them, a quaternary amine salt having a molecular weight of 10 3 to
10 6 polymers are effective.
【００１１】[0011]
【化１】 [Chemical 1]
【００１２】具体的には次に示すポリアミン（ＰＡ）あ
るいはポリアミンスルホン（ＰＡＳ）のポリマーがＣｒ
析出促進剤として最も効果的である。アミン基による陰
極面への吸着作用、アルキル基によるＺｎイオンの析出
抑制、スルホン基へのＣｒ3+イオンの配位結合などが寄
与していると考えられる。Specifically, the following polyamine (PA) or polyamine sulfone (PAS) polymer is Cr.
Most effective as a precipitation accelerator. It is considered that the contribution of the amine group to the cathode surface, the suppression of Zn ion precipitation by the alkyl group, and the coordinate bond of Cr 3+ ion to the sulfone group are considered to contribute.
【００１３】[0013]
【化２】 [Chemical 2]
【００１４】この他、１、２、３級アミンのポリマーも
４級アミンポリマーには及ばないもののＣｒ析出促進剤
として有効である。カチオンポリマー以外では、ポリオ
キシアルキレン誘導体、中でも次に示すポリエチレング
リコール（ＰＥＧ）が有効である。In addition to these, polymers of 1, 2, and 3 amines are effective as Cr precipitation accelerators although they do not reach the quaternary amine polymers. Other than the cationic polymer, polyoxyalkylene derivatives, especially polyethylene glycol (PEG) shown below are effective.
【００１５】[0015]
【化３】 [Chemical 3]
【００１６】第２めっき層のめっき付着量は特に限定さ
れるものではないが、耐食性上は１０ｇ／ｍ2以上、電
気めっきラインで生産する上ではコスト的に５０ｇ／ｍ
2以下が好ましい。第３めっき層は第２めっき層のりん
酸処理性を向上させる作用により塗装後性能をさらに向
上せしめる。第２めっき層はＣｒを多量に含有するた
め、現状のりん酸塩処理では緻密なりん酸塩処理皮膜が
形成されにくい。このような状態でも、Ｃｒの効果によ
り塗装後耐食性は従来公知のＺｎ−Ｎｉ、Ｚｎ−Ｆｅな
どより優れるが、第３めっき層として緻密なりん酸塩処
理皮膜が形成されるＺｎめっきもしくはＺｎ系合金めっ
きを設けると、一段と優れた塗装後耐食性が発揮され
る。ここで用いられるＺｎ系合金めっきとは、例えば２
０％以下のＮｉあるいは９０％以下のＦｅを含むりん酸
塩処理性に優れた合金めっきである。第３めっき層の付
着量は０．１〜５ｇ／ｍ2が好ましい。０．１ｇ／ｍ2未
満では緻密なりん酸塩処理皮膜が形成されにくく、５ｇ
／ｍ2を超えると第３めっき層の性質が強く出て塗装後
耐食性が低下し、好ましくない。りん酸塩処理性と塗装
後耐食性の観点からは、０．５〜３ｇ／ｍ2の範囲がよ
り好ましい。The coating amount of the second plating layer is not particularly limited, but it is not less than 10 g / m 2 in terms of corrosion resistance and 50 g / m 2 in cost for production in an electroplating line.
2 or less is preferable. The third plating layer further improves the post-coating performance by the action of improving the phosphoric acid treatment property of the second plating layer. Since the second plating layer contains a large amount of Cr, it is difficult to form a dense phosphatized film by the present phosphate treatment. Even in such a state, the corrosion resistance after coating is superior to that of conventionally known Zn-Ni, Zn-Fe, etc. due to the effect of Cr, but Zn plating or Zn-based plating in which a dense phosphatized film is formed as the third plating layer When alloy plating is provided, the corrosion resistance after painting is further enhanced. The Zn alloy plating used here is, for example, 2
An alloy plating containing 0% or less of Ni or 90% or less of Fe and excellent in phosphating property. The adhesion amount of the third plating layer is preferably 0.1 to 5 g / m 2 . If it is less than 0.1 g / m 2, it is difficult to form a dense phosphatized film and it is 5 g.
If it exceeds / m 2 , the property of the third plating layer becomes strong and the corrosion resistance after coating is lowered, which is not preferable. From the viewpoint of phosphating property and corrosion resistance after coating, the range of 0.5 to 3 g / m 2 is more preferable.
【００１７】本発明の複層電気めっき鋼板は、鋼板に脱
脂、酸洗の前処理を施した後、第１めっき層としてＺｎ
めっき、第２めっき層としてＺｎ系複合電気めっき、必
要に応じて第３めっき層としてＺｎもしくはＺｎ系合金
めっきを施すことにより得られる。第１めっき層、第３
めっき層の形成方法は、特に限定されないが、鋼板表面
を少ない付着量で均一に被覆する目的からは、硫酸酸性
浴を用いて電気密度１０〜１００Ａ／ｄｍ2で行なうこ
とが最良である。第２めっき層は、Ｚｎ2+、Ｃｒ3+、さ
らにはＣｏ2+、Ｆｅ2+、Ｎｉ2+の１種以上をそれぞれ１
０〜１００ｇ／ｌ含有し、かつＣｒ析出促進剤としてＰ
ＡＳに代表されるカチオンポリマーあるいはＰＥＧなど
の有機高分子を０．０１〜２０ｇ／ｌ含有するｐＨ０．
５〜３、浴温４０〜７０℃の硫酸酸性浴を用いて、電流
密度２０Ａ／ｄｍ2以上、液流速１ｍ／ｍｉｎ以上で電
気めっきを行なえばよい。めっき浴中には、Ｎａ+、Ｎ
Ｈ4 +などの電導度助剤、ほう酸などの緩衝剤、あるいは
耐食性をさらに向上させるためにＳｉＯ2、ＴｉＯ2、Ａ
ｌ2Ｏ3などの酸化物粒子やＢａＣｒＯ4などの難溶性ク
ロム酸塩粒子を添加してもよい。本発明の構造は鋼板の
両面に対して用いてもよいし、片面のみに適用し他の面
は鋼板面のままあるいは他のめっき層としてもよい。ま
た上層に有機皮膜を施した有機複合めっき鋼板の下地め
っきに適用してもよい。The multi-layer electroplated steel sheet of the present invention is applied to a steel sheet.
After the pretreatment of oil and pickling, Zn was used as the first plating layer.
Plating, Zn-based composite electroplating as the second plating layer, required
If necessary, Zn or a Zn-based alloy is used as the third plating layer.
It is obtained by plating. First plating layer, third
The method for forming the plating layer is not particularly limited, but the steel plate surface
Sulfuric acid is used for the purpose of uniformly coating
Electric density of 10 to 100 A / dm using bath2Do it in
And is the best. The second plating layer is Zn2+, Cr3+,
To Co2+, Fe2+, Ni2+1 or more of each
0-100 g / l content and P as Cr precipitation promoter
Cationic polymer represented by AS or PEG
Containing 0.01 to 20 g / l of the organic polymer of pH 0.
5-3, using sulfuric acid acidic bath with a bath temperature of 40-70 ℃, current
Density 20A / dm2Above, electricity at a liquid flow rate of 1 m / min or more
Air plating may be performed. Na in the plating bath+, N
HFour +Conductivity aids such as, buffering agents such as boric acid, or
SiO to further improve corrosion resistance2, TiO2, A
l2O3Oxide particles such as BaCrOFourDifficult to dissolve
Romate particles may be added. The structure of the present invention is
May be used on both sides, or applied on only one side and the other side
May be used as it is on the steel plate surface or as another plating layer. Well
Of the organic composite plated steel sheet with the organic film on the upper layer
It may be applied as is.
【００１８】[0018]
【実施例】冷延鋼板を、アルカリ脱脂し、５％硫酸水溶
液で酸洗した後、以下の条件で電気めっきを行なった。
第１めっき層は、Ｚｎ2+を含むｐＨ２、浴温６０℃の硫
酸酸性浴を用いて形成させた。第２めっき層は、Ｚ
ｎ2+、Ｃｒ3+及びＣｏ2+、Ｆｅ 2+、Ｎｉ2+のうち１種以
上、さらには有機高分子（平均分子量１０万のＰＡ、平
均分子量３５００のＰＡＳ、平均分子量１５００のＰＥ
Ｇ）、およびＮａ+を含むｐＨ１〜２、浴温５５℃の硫
酸酸性浴を用いて形成させた。第３めっき層は、Ｚｎ2+
またはさらにＦｅ2+、Ｎｉ2+を含むｐＨ１．５、浴温６
０℃の硫酸酸性浴を用いて形成させた。めっき組成はめ
っき浴組成及び電流密度で制御し、付着量は通電量によ
り制御した。表１にめっき組成と耐衝撃密着性および塗
装後耐食性の関係を示す。評価方法は以下の通りであ
る。Example: Cold-rolled steel sheet was degreased with alkali and 5% sulfuric acid solution was added.
After pickling with a liquid, electroplating was performed under the following conditions.
The first plating layer is Zn2+Sulfuric acid containing pH2 and bath temperature of 60 ℃
Formed using an acid-acid bath. The second plating layer is Z
n2+, Cr3+And Co2+, Fe 2+, Ni2+More than one
Above all, organic polymers (PA with average molecular weight of 100,000, flat
PAS with an average molecular weight of 3500, PE with an average molecular weight of 1500
G), and Na+Sulfuric acid containing 1 to 2 and bath temperature 55 ° C
Formed using an acid-acid bath. The third plating layer is Zn2+
Or even Fe2+, Ni2+PH including 1.5, bath temperature 6
Formed using a 0 ° C. sulfuric acid bath. Plating composition fit
It is controlled by the bath composition and the current density.
Controlled. Table 1 shows the plating composition, impact resistance and coating.
The relationship between corrosion resistance after wearing is shown. The evaluation method is as follows
It
【００１９】（１）耐衝撃密着性 試験片に浸漬型りん酸塩処理、カチオン電着塗装３０μ
を施し、中塗り、上塗り塗装をそれぞれ４０μ施し、合
計膜厚１１０μとした。その後、試験片温度−２０℃で
ＪＩＳ７号砕石２５０ｇを速度１５０ｋｍ／ｈｒで試験
片に衝突させる低温ピッチング試験を行ない、テープ剥
離後のめっき剥離面積を５段階で評価した。 評点５（良：めっき剥離０．１％以下）−評点１（不
良：めっき剥離１０％超）(1) Impact resistance Adhesion resistance Test pieces are immersed in phosphate treatment, and cationic electrodeposition coating 30 μ
Then, 40 μm of each of the intermediate coating and the top coating was applied to give a total film thickness of 110 μm. After that, a low temperature pitting test was carried out in which 250 g of JIS No. 7 crushed stone was collided with the test piece at a speed of 150 km / hr at a test piece temperature of -20 ° C, and the plating peeled area after tape peeling was evaluated on a scale of five. Rating 5 (good: plating peeling 0.1% or less) -rating 1 (poor: plating peeling more than 10%)
【００２０】（２）塗装後耐食性 チッピング疵の耐食性 耐衝撃密着性を評価した試験片をそのまま週２回塩水を
散布しつつ屋外暴露を行ない、３ヵ月後の赤錆発生面積
で評価した。 評点５（良：赤錆発生無し）−評点１（不良：赤錆発生
１０％超） クロスカット疵の耐食性 （１）と同様の塗装を行ない、カッターナイフで地鉄に
達するクロスカット疵を入れ、下記のサイクル腐食試験
を１００サイクル行ない、塗膜ふくれ巾で評価した。 サイクル腐食試験 ＳＳＴ４時間−乾燥２時間−湿潤２
時間 評点５（良：ふくれ巾２ｍｍ以下）−評点１（不良：ふ
くれ巾１０ｍｍ超）(2) Corrosion resistance after coating Corrosion resistance of chipping flaw The test piece evaluated for impact resistance was subjected to outdoor exposure while spraying salt water twice a week as it was, and evaluated for the area where red rust occurred after 3 months. Rating 5 (Good: No red rust) -Rating 1 (Poor: Red rust greater than 10%) Corrosion resistance of cross-cut flaws Perform the same coating as in (1), insert a cross-cut flaw that reaches the base iron with a cutter knife, The cycle corrosion test was conducted 100 times and the coating film swelling was evaluated. Cycle corrosion test SST 4 hours-dry 2 hours-wet 2
Time Score 5 (Good: Blister width of 2 mm or less) -Score 1 (Poor: Blister width of more than 10 mm)
【００２１】表１において、比較例１は第１めっき層が
ないため、耐衝撃密着性およびチッピング疵の耐食性が
不良である。比較例２は第１めっき層の付着量が多すぎ
るため、比較例３は第２めっき層のＣｒ含有率が低すぎ
るため、何れも耐衝撃密着性は良好なものの塗装後耐食
性が不十分であり、比較例４は第２めっき層のＣｒ含有
率が高すぎるため、耐衝撃密着性およびチッピング疵の
耐食性が不良である。比較例５は第２めっき層のＮｉ含
有率が低すぎるため、クロスカット疵の耐食性が不十分
であり、比較例６は第２めっき層のＮｉ含有率が高すぎ
るため、耐衝撃密着性および塗装後耐食性が不良であ
る。In Table 1, Comparative Example 1 does not have the first plating layer, so that the impact resistance and the corrosion resistance of chipping flaws are poor. In Comparative Example 2, the adhesion amount of the first plating layer was too large, and in Comparative Example 3, the Cr content of the second plating layer was too low. Therefore, in all cases, the impact adhesion was good, but the corrosion resistance after coating was insufficient. In Comparative Example 4, since the Cr content of the second plating layer was too high, the impact resistance and the corrosion resistance of chipping flaws were poor. In Comparative Example 5, since the Ni content of the second plating layer is too low, the corrosion resistance of the cross-cut flaw is insufficient, and in Comparative Example 6, the Ni content of the second plating layer is too high, and therefore the impact resistance and the adhesion resistance are low. Poor corrosion resistance after painting.
【００２２】比較例７はめっき浴に有機高分子を添加せ
ず電流密度を極端に高くしてＣｒを析出させたものであ
るが、Ｃｒは金属ではなく酸化物として析出しており、
耐衝撃密着性、塗装後耐食性ともに不良である。比較例
８は第３めっき層の付着量が多すぎるため、塗装後耐食
性が低下している。比較例９は第１めっき層としてＮｉ
を施したものであるが、耐衝撃密着性は良好なもののチ
ッピング疵の耐食性は不十分である。これに対して、第
１めっき層、第２めっき層が所定範囲にある本発明例は
何れも耐衝撃密着性、塗装後耐食性ともに良好であり、
さらに第３めっき層を有する本発明例は、クロスカット
疵の耐食性が一段と優れたものになる。In Comparative Example 7, Cr was deposited by adding extremely high current density without adding an organic polymer to the plating bath, but Cr was deposited as an oxide rather than a metal.
Both impact resistance and corrosion resistance after painting are poor. In Comparative Example 8, since the adhesion amount of the third plating layer was too large, the corrosion resistance after coating was lowered. Comparative Example 9 uses Ni as the first plating layer.
Although the impact resistance is good, the chipping flaw has insufficient corrosion resistance. On the other hand, all of the examples of the present invention in which the first plating layer and the second plating layer are in the predetermined range have good impact adhesion and corrosion resistance after coating.
Furthermore, in the example of the present invention having the third plating layer, the corrosion resistance of cross-cut flaws is further improved.
【００２３】[0023]
【表１】 [Table 1]
【００２４】[0024]
【発明の効果】以上述べた如く、本発明の複層電気めっ
き鋼板は、塗装後低温下で優れた耐衝撃密着性を有し、
かつ裸の耐食性のみならず塗装後耐食性にも優れた高性
能のめっき鋼板であり、特に自動車用防錆鋼板として好
適である。As described above, the multi-layer electroplated steel sheet of the present invention has excellent impact resistance and adhesion at low temperature after coating,
It is a high-performance plated steel sheet that is excellent not only in bare corrosion resistance but also in corrosion resistance after painting, and is particularly suitable as an anticorrosion steel sheet for automobiles.
Claims (3)
０．０１〜２ｇ／ｍ 2のＺｎめっき層が形成され、この
上に第２めっき層としてＣｒを５〜３０重量％、Ｆｅ、
Ｃｏ、Ｎｉのうち１種もしくは２種以上を０．１〜１０
重量％、有機高分子を０．００１〜５重量％含有するＺ
ｎ系複合電気めっき層が形成されたことを特徴とする高
耐食性複層電気めっき鋼板。1. The amount of adhesion as a first plating layer on the surface of a steel plate
0.01-2 g / m 2Zn plating layer of is formed,
5-30% by weight of Cr as the second plating layer, Fe,
0.1 to 10 of 1 or 2 or more of Co and Ni
% Z, containing 0.001 to 5% by weight of organic polymer
n-type composite electroplating layer is formed
Corrosion resistant multi-layer electroplated steel sheet.
て付着量０．１〜５ｇ／ｍ2のＺｎもしくはＺｎ系合金
めっき層が形成された請求項１記載の高耐食性複層電気
めっき鋼板。2. The highly corrosion-resistant multi-layered electric layer according to claim 1, wherein a Zn or Zn-based alloy plating layer having a deposition amount of 0.1 to 5 g / m 2 is formed on the second plating layer as a third plating layer. Plated steel sheet.
が、カチオンポリマーである請求項１及び２記載の高耐
食性複層電気めっき鋼板。3. The high corrosion-resistant multi-layer electroplated steel sheet according to claim 1, wherein the organic polymer contained in the second plating layer is a cationic polymer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4223113A JP2707477B2 (en) | 1992-08-24 | 1992-08-24 | High corrosion resistant multi-layer electroplated steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4223113A JP2707477B2 (en) | 1992-08-24 | 1992-08-24 | High corrosion resistant multi-layer electroplated steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0665759A true JPH0665759A (en) | 1994-03-08 |
| JP2707477B2 JP2707477B2 (en) | 1998-01-28 |
Family
ID=16793031
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4223113A Expired - Lifetime JP2707477B2 (en) | 1992-08-24 | 1992-08-24 | High corrosion resistant multi-layer electroplated steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2707477B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4845056A (en) * | 1987-10-09 | 1989-07-04 | Allied-Signal Inc. | Continuous process for production of fine particulate ceramics |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6036694A (en) * | 1983-08-09 | 1985-02-25 | Sumitomo Metal Ind Ltd | Multi-layer electroplated steel sheet |
| JPS6134520A (en) * | 1984-12-28 | 1986-02-18 | Hamai Seisakusho:Kk | Kaleidoscopic photographic device |
| JPS6314892A (en) * | 1986-07-07 | 1988-01-22 | Nippon Kokan Kk <Nkk> | Production of multi-ply electroplated steel sheet |
| JPH01294897A (en) * | 1988-05-20 | 1989-11-28 | Nkk Corp | Surface-treated steel sheet excellent in suitability for chemical treatment and coating and excellent in corrosion resistance |
| JPH046298A (en) * | 1990-04-25 | 1992-01-10 | Nippon Steel Corp | High corrosion resistance composite electroplated steel sheet excellent in plating adhesion |
-
1992
- 1992-08-24 JP JP4223113A patent/JP2707477B2/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6036694A (en) * | 1983-08-09 | 1985-02-25 | Sumitomo Metal Ind Ltd | Multi-layer electroplated steel sheet |
| JPS6134520A (en) * | 1984-12-28 | 1986-02-18 | Hamai Seisakusho:Kk | Kaleidoscopic photographic device |
| JPS6314892A (en) * | 1986-07-07 | 1988-01-22 | Nippon Kokan Kk <Nkk> | Production of multi-ply electroplated steel sheet |
| JPH01294897A (en) * | 1988-05-20 | 1989-11-28 | Nkk Corp | Surface-treated steel sheet excellent in suitability for chemical treatment and coating and excellent in corrosion resistance |
| JPH046298A (en) * | 1990-04-25 | 1992-01-10 | Nippon Steel Corp | High corrosion resistance composite electroplated steel sheet excellent in plating adhesion |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4845056A (en) * | 1987-10-09 | 1989-07-04 | Allied-Signal Inc. | Continuous process for production of fine particulate ceramics |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2707477B2 (en) | 1998-01-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS6160914B2 (en) | ||
| JP2707478B2 (en) | High corrosion resistant multi-layer electroplated steel sheet | |
| JP2707477B2 (en) | High corrosion resistant multi-layer electroplated steel sheet | |
| JPH0210236B2 (en) | ||
| JPH0536518B2 (en) | ||
| JPH055914B2 (en) | ||
| JPH0645918B2 (en) | High corrosion resistance composite electroplated steel sheet with excellent plating adhesion | |
| JPH0512439B2 (en) | ||
| JP2665297B2 (en) | Manufacturing method of zinc-based plated aluminum sheet | |
| JPH04337098A (en) | Zn-ni-mo multi-ply electrogalvanized steel sheet excellent in corrosion resistance and plating adhesion | |
| JPS61194195A (en) | Highly-corrosion resistant two-layer plated steel plate | |
| JPS61130498A (en) | Composite plated steel sheet having superior corrosion resistance before and after coating with paint | |
| JPH0249397B2 (en) | KOTAISHOKUSEIHYOMENSHORIKOHAN | |
| JPH0411636B2 (en) | ||
| JPH046299A (en) | High corrosion resistance composite electroplated steel sheet excellent in plating adhesion and performance after coating | |
| JPH01290796A (en) | Electroplated steel sheet having high corrosion resistance | |
| JPS61119694A (en) | Production of electroplated steel plate | |
| JPH05311481A (en) | Production of zinc electroplated steel sheet having high corrosion resistance | |
| JPH0765224B2 (en) | Steel sheet with multi-layer plating with excellent processing method, corrosion resistance and water-resistant adhesion | |
| JPH0672317B2 (en) | Highly corrosion resistant composite electroplated steel sheet excellent in chemical conversion treatment and method for producing the same | |
| JPH0715153B2 (en) | Zinc-chromium multi-layer electroplated steel sheet | |
| JPS5925993A (en) | Surface-treated steel plate with high corrosion resistance | |
| JPH0672318B2 (en) | Highly corrosion resistant composite electroplated steel sheet excellent in chemical conversion treatability and weldability, and method for producing the same | |
| JPH04116195A (en) | Manufacture of zn series alloy electroplated steel plate excellent in chipping resistance | |
| JPH05125593A (en) | Production of highly corrosion-resistant zn electroplated steel sheet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 19970916 |