JPS627889A - Zinc or zinc alloy plated steel sheet having superior corrosion resistance and paintability - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance of the resulting titled plated steel sheet and the paintability including the adhesion to a paint film and the corrosion resistance after painting by forming a Zn or Zn alloy layer on a steel sheet having a specified composition by plating. CONSTITUTION:One side or both sides of a steel sheet having a composition contg., by weight, <=0.15% C, 0.005-0.10% acid-sol. Al and 1.5-20% Cr are plated with Zn or a Zn alloy. The steel composition may further contain 0.03-0.50% one or more among Ti, Nb, V and Zr. An Ni or Ni alloy undercoat layer may be formed as an intermediate layer between the steel sheet and the resulting Zn or Zn alloy layer. The plated steel sheet has superior corrosion resistance in a corrosive environment contg. Cl<-> and superior paintability, so it is suitable for use as a steel sheet for an automobile, a building material or the like.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、Ｎａ０文、ＣａＣ文２等の存在するＣｌ−イ
オンが含有される腐食環境に曝された場合の耐食性、塗
装性能にすぐれ自動車用防錆鋼板、建築材料等に使用さ
れる亜鉛系メッキ鋼板に関する。Detailed Description of the Invention (Industrial Field of Application) The present invention provides excellent corrosion resistance and coating performance when exposed to a corrosive environment containing Cl- ions such as Na0 and CaC2. This product relates to zinc-based plated steel sheets used for rust-proofing steel sheets, building materials, etc.

（従来技術とその問題点） 従来から自動車用鋼板には防錆被覆層が施されていない
、いわゆる冷延鋼板が使われて来た。この冷延鋼板は、
自動車会社で自動車の各種部材に加工され、組立てられ
た後、燐酸塩処理を施し。(Prior art and its problems) Conventionally, so-called cold-rolled steel sheets without a rust-preventing coating layer have been used as steel sheets for automobiles. This cold rolled steel plate is
After being processed and assembled into various parts of automobiles at automobile companies, they are treated with phosphate.

次いで塗装される。即ち自動車に使用される冷延鋼板は
、塗膜によって腐食から保護されている。It is then painted. That is, cold-rolled steel sheets used in automobiles are protected from corrosion by a coating film.

しかし近年になって自動車の耐久性向上、特に腐食に基
因する耐久性向上の要求が高くなり、従来の塗装のみで
はこの要求に必ずしも対処出来なくなった。例えば、冬
期、道路の凍結を防止するため境を散布するカナダにお
いては、１９８５年（７）自動車の車体腐食に関するガ
イドラインとして“ｌＯ年間孔あきなし”及び″５年間
錆発生なし°゛を目標にしている。このガイドラインは
“カナダコード′°として知られ、このため車体防錆に
対する目標として各種対策が採られつつある。However, in recent years, there has been a growing demand for improved durability of automobiles, particularly for improved durability due to corrosion, and conventional painting alone cannot necessarily meet this demand. For example, in Canada, where road boundaries are sprayed to prevent roads from freezing in the winter, the 1985 (7) guidelines for car body corrosion set the goals of "no holes for 1 year" and "no rust for 5 years." This guideline is known as the “Canadian Code”, and for this reason, various measures are being taken as a goal for car body rust prevention.

現在、冷延鋼板の耐食性、塗装後の耐食性を向上し、か
つ加工性を損なわずに量産可能なものとして、電気亜鉛
メッキ鋼板が広く使われている。Currently, electrogalvanized steel sheets are widely used because they improve the corrosion resistance of cold-rolled steel sheets and the corrosion resistance after painting, and can be mass-produced without impairing workability.

しかし、亜鉛メッキ鋼板の亜鉛層自体はＣ見−を含有す
る前記の如き苛酷な腐食環境においてすぐれた耐食性を
示すものの、亜鉛が地鉄（メッキ原板）より極めてアノ
−ディック（Ａｎｏｄｉｃ）であるため、地鉄に対する
犠牲防食能による溶解・腐食速度が大きく、比較的短期
間で亜鉛の防食作用が失なわれ、長期間の耐食寿命が得
られにくい。However, although the zinc layer itself of a galvanized steel sheet exhibits excellent corrosion resistance in the above-mentioned severe corrosive environment containing C, zinc is much more anodic than the base steel (plated original sheet). The rate of dissolution and corrosion due to the sacrificial anticorrosive ability against the base steel is high, and the anticorrosive effect of zinc is lost in a relatively short period of time, making it difficult to obtain a long corrosion resistant life.

耐食性の向上にはメッキ量を増す事が最も簡惟な方法で
ある。しかし、メッキ量の増加は電気メッキでは著るし
い生産性の低下とコスト上昇をもたらし、経済的に望ま
しくないばかりでなく、加工性、溶接性等の面でも次の
様な問題がある。The simplest way to improve corrosion resistance is to increase the amount of plating. However, an increase in the amount of plating causes a significant decrease in productivity and an increase in cost in electroplating, which is not only economically undesirable, but also poses the following problems in terms of workability, weldability, etc.

即ち、メッキ鋼板を自動車部品に加工する際、特に絞り
加工において、メッキ層が剥離したり、又その一部が削
り取られて（所謂パウダリング）プレス金型に堆積し、
成品に疵を生じる現像がある。この様なパウダリングを
起すと、金型の手入れで生産性が著るしく落ちるばかり
でなく、成品の性能にも悪影響がある所から、メッキ量
を少なくする必要がある。一方加工された各種部材の組
立ては、殆んど抵抗溶接（スポット溶接）が使われ、溶
接性の良悪が重視されている。溶接性にイ±、メッキ量
が大きく影テし、メッキ量がある程度以上に増えると、
溶接部の強度不足、外観不良等の欠陥を生じ易くなり、
更には溶接電極寿命の著るしい低下が生じる。従って、
加工性、溶接性の見地から、出来るだけ低メッキ量が望
ましい。That is, when processing plated steel sheets into automobile parts, especially during drawing, the plating layer may peel off or a portion of it may be scraped off (so-called powdering) and deposited on the press die.
There is a development process that causes defects on the finished product. If such powdering occurs, not only will productivity be significantly reduced due to maintenance of the mold, but it will also have an adverse effect on the performance of the finished product, so it is necessary to reduce the amount of plating. On the other hand, resistance welding (spot welding) is mostly used to assemble various processed parts, and importance is placed on the quality of weldability. Weldability is affected by the amount of plating, and if the amount of plating increases beyond a certain level,
Defects such as insufficient strength of welded parts and poor appearance are likely to occur.
Furthermore, the life of the welding electrode is significantly reduced. Therefore,
From the viewpoint of workability and weldability, it is desirable to have as little plating amount as possible.

更に、自動車用亜鉛メッキ鋼板は最終的には塗装される
が、塗膜欠陥部や塗膜を浸透した腐食性水溶液に亜鉛が
腐食され易いために、塗膜面“ふくれ゛（所謂ブリスタ
ー）を発生し、塗膜が素地から浮き上り剥離するという
欠点がある。Furthermore, although galvanized steel sheets for automobiles are eventually painted, the zinc is easily corroded by the corrosive aqueous solution that has penetrated the paint film and the defective parts of the paint film, resulting in "blistering" on the paint film surface. This has the disadvantage that the paint film lifts up and peels off from the substrate.

これらの塗膜剥離部分から腐食が進行し、その耐食寿命
が著しく減じる欠点があった。Corrosion progresses from these areas where the paint film has peeled off, resulting in a disadvantage that the corrosion resistance life is significantly reduced.

又、同様に屋根、壁材料等の建築用材料として使用され
る場合も長期耐食寿命が要求され、その耐食性向上の要
望が高い。Similarly, when used as a building material such as a roof or wall material, a long corrosion resistant life is required, and there is a strong desire to improve the corrosion resistance.

これらの場合も塗装されて使用されることが多く、前記
と同様に塗膜欠陥部或いは塗膜を浸透した腐食性水溶液
が亜鉛を腐食し、塗膜面に“フクレ”　（所謂、ブリス
ター）を発生し、塗膜が素地から剥離し、塗膜剥離部分
からの腐食が進行し、その耐食寿命を著しく劣化する欠
点があった。In these cases, they are often used after being painted, and similarly to the above, the defective parts of the paint film or the corrosive aqueous solution that has penetrated the paint film corrode the zinc, causing "blisters" (so-called blisters) on the paint film surface. The paint film peels off from the base, and corrosion progresses from the peeled part of the paint film, resulting in a significant deterioration of its corrosion resistance life.

このような問題は、亜鉛メッキ鋼板のみならず、亜鉛系
メッキ鋼板（ここで「亜鉛系」とは亜鉛を主成分とする
共晶組織の亜鉛合金、或いは亜鉛に対してポリアミド系
、ポリイミド系等の有機物を含んでいるもの、あるいは
リン、シリカ、アルミナ等の無機物を含んでいるものも
意味する）においても、メッキ層自体の腐食環境での腐
食速度は合金化によって向上するものの、犠牲防食作用
は合金メッキ層中の亜鉛に依存するため耐食性、塗膜性
等を劣化する問題がしばしばあった。Such problems occur not only with galvanized steel sheets, but also with zinc-based plated steel sheets (here, "zinc-based" refers to zinc alloys with a eutectic structure containing zinc as the main component, or polyamide-based, polyimide-based, etc. (This also means those containing organic substances such as phosphorus, silica, alumina, etc.) Although the corrosion rate of the plating layer itself in a corrosive environment is improved by alloying, the sacrificial corrosion protection effect Because it depends on zinc in the alloy plating layer, there were often problems with deterioration of corrosion resistance, coating properties, etc.

（問題点を解決するための手段） 木発明者は、かかる亜鉛メッキ鋼板或いは亜鉛系メッキ
鋼板の問題点を解決し、耐食性、端面部の耐食性或いは
塗膜密着性、塗装後耐食性衡等の塗装性能にすぐれた亜
鉛系メッキ鋼板を得ることを目的に種々の検討を行なっ
た。(Means for Solving the Problems) The inventor of the invention solved the problems of the galvanized steel sheets or zinc-based plated steel sheets, and improved the corrosion resistance, the corrosion resistance of the end faces, the adhesion of the paint film, and the corrosion resistance after painting. Various studies were conducted with the aim of obtaining zinc-plated steel sheets with excellent performance.

その結果、亜鉛系メッキ鋼板の原板鋼成分を調整して、
亜鉛のアノード防食機能を確保すると共に、そのメッキ
原板に対するカップル腐食電流を減少せしめ、メッキ欠
陥部或いはメッキ鋼板端面での亜鉛の犠牲防食による溶
解速度を抑制する事によって、メッキ鋼板の耐食性及び
耐孔食性の向上或いは端面部からの腐食が防止できる事
がわかった。また、さらに塗膜との密着性がすぐれた塗
装下地処理を施した場合には、塗膜欠陥部や塗膜下のメ
ッキ欠陥部、端面等において、亜鉛の腐食速度の抑制に
よる亜鉛の腐食生成物に起因する塗膜フクレ（所謂、ブ
リスター）、塗膜剥離の防止、塗膜剥離部分の減少によ
る塗装−後の耐食性の向上が可能である事がわかった。As a result, by adjusting the raw steel composition of galvanized steel sheet,
By ensuring the anode corrosion protection function of zinc, reducing the couple corrosion current to the plated original plate, and suppressing the dissolution rate due to sacrificial corrosion protection of zinc at the plating defect area or the end face of the plated steel plate, it improves the corrosion resistance and hole resistance of the plated steel plate. It was found that the edibility could be improved or corrosion from the end surface could be prevented. In addition, when a coating base treatment with excellent adhesion to the paint film is applied, zinc corrosion is generated by suppressing the corrosion rate of zinc in defective parts of the paint film, plating defects under the paint film, edges, etc. It has been found that it is possible to prevent paint film blistering (so-called blistering) and paint film peeling caused by substances, and to improve post-painting corrosion resistance by reducing the peeled area of the paint film.

即ち、メッキ原板にＣｒを添加した鋼板及び該鋼板にＴ
ｆ、Ｎｂ、Ｖ、Ｚｒの１種又は２種以上を適宜成分調整
して添加した鋼板に、亜鉛メッキ層或いは亜鉛系メッキ
層を施す事によって、メッキ原板とメッキ層との相互作
用或いは相剰効果による上記の如き耐食性、塗装性能の
向上が可能である事がわかった。That is, a steel plate in which Cr is added to the plated original plate and T added to the steel plate.
By applying a zinc plating layer or a zinc-based plating layer to a steel sheet to which one or more of f, Nb, V, and Zr are added with appropriate composition adjustment, interaction or mutual overlap between the plating original sheet and the plating layer can be prevented. It was found that it is possible to improve corrosion resistance and coating performance as described above.

また、さらに上記組成のメッキ鋼板にＮｉ系の下地被覆
層を施す事によって、その性能向上効果がより一層助長
される事を見出した。Furthermore, it has been found that by further applying a Ni-based base coating layer to the plated steel sheet having the above composition, the effect of improving its performance is further promoted.

而して、その要旨は、 （１）重量％で、 Ｃ；Ｑ、１５％以下、酸可溶Ａ又；　０．００５〜０．
１０％、Ｃｒ；１．５〜２０％を含有する鋼板の片面又
は両面に、亜鉛メッキ層或いは亜鉛系メッキ層を施して
なる耐食性及び塗装性にすぐれた亜鉛系メッキ鋼板。The gist is as follows: (1) In weight%: C; Q; 15% or less; acid-soluble A; 0.005 to 0.
A zinc-plated steel sheet with excellent corrosion resistance and paintability, which is obtained by applying a zinc plating layer or a zinc-based plating layer to one or both sides of a steel sheet containing Cr: 10% and 1.5 to 20%.

（２）重量％で、 Ｃ；　０．１５％以下、酸可溶Ａ　ｆｉ　；　０．ＱＱ
５〜０．１０％、Ｃｒ；１．５〜２０％、にＴｉ、Ｎｂ
、Ｖ。(2) In weight %: C; 0.15% or less; acid-soluble A fi; 0. QQ
5-0.10%, Cr; 1.5-20%, Ti, Nb
,V.

Ｚｒの１種又は２種以上で０．０３〜０．５０％を含有
する鋼板の片面又は両面に、亜鉛メッキ層或いは亜鉛系
メッキ層を施してなる耐食性及び塗装性にすぐれた亜鉛
系メッキ鋼板。A zinc-plated steel sheet with excellent corrosion resistance and paintability, which is obtained by applying a galvanized layer or a zinc-based plating layer to one or both sides of a steel sheet containing 0.03 to 0.50% of one or more types of Zr. .

（３）重量％で、 Ｃ；　Ｑ、１５％以下、酸可溶Ａ　ｌ　、　０．００５
〜０．１０％、Ｃｒ　；　１．５〜２０％、を含有する
鋼板の片面又は両面に、Ｎｉ系下地被覆層と亜鉛メッキ
層或いは亜鉛系メッキ層を施してなる耐食性及び塗装性
にすぐれた亜鉛系メッキ鋼板。(3) In weight %, C; Q, 15% or less, acid-soluble A l , 0.005
~0.10%, Cr; 1.5~20%, on one or both sides of a steel plate with a Ni-based base coating layer and a galvanized layer or a zinc-based plating layer, which has excellent corrosion resistance and paintability. Galvanized steel sheet.

（４）重量％で、 Ｃ；　０．１５％以下、酸可溶Ａ交、　０．００５〜０
．１０％、Ｃｒ；１．５〜２０％、にＴｉ、Ｎｂ、Ｖ。(4) In weight%, C: 0.15% or less, acid-soluble A, 0.005 to 0
．． 10%, Cr; 1.5-20%, Ti, Nb, V.

Ｚｒの１種又は２種以上で０．０３〜０．５０％を含有
する鋼板の片面又は両面に、Ｎｉ系下地被覆層と亜鉛メ
ッキ層或いは亜鉛系メッキ層を施してなる耐食性と塗装
性にすぐれた亜鉛系メッキ鋼板を提供することなある。Corrosion resistance and paintability obtained by applying a Ni-based base coating layer and a galvanized layer or a zinc-based plating layer to one or both sides of a steel plate containing 0.03 to 0.50% of one or more types of Zr. We provide excellent galvanized steel sheets.

“以下、本発明について詳細に説明する。“Hereinafter, the present invention will be explained in detail.

通常の鋼板製造工程を経て製造された前記鋼成分の鋼板
をメッキ原板として使用する。亜鉛系メッキ鋼板が使用
される腐食環境、特にその腐食が著しいＣ１−イオン含
有腐食環境において、Ｃｒを１．５％以上含有する鋼板
、特にＣｒ含有量が３％以−ヒ含有される鋼板は、Ｃｒ
を不可避的不純物程度しか含有していない鋼板に比べす
ぐれた耐食性を示す。A steel plate having the above-mentioned steel components manufactured through a normal steel plate manufacturing process is used as a plating base plate. In a corrosive environment where zinc-based plated steel sheets are used, especially in a corrosive environment containing C1- ions where the corrosion is significant, steel sheets containing 1.5% or more of Cr, especially steel sheets containing 3% or more of Cr, are ,Cr
It exhibits superior corrosion resistance compared to steel sheets that contain only a small amount of unavoidable impurities.

それと同時に、第１図に僧示すもように。At the same time, as shown in Figure 1.

Ｃｆ１．−イオン含有腐食環境において、Ｃｒ含有量が
１．５％以上で、亜鉛メッキ層とメッキ原板のカップル
腐食電流が著しく減少する。Cf1. - In an ion-containing corrosion environment, when the Cr content is 1.5% or more, the coupled corrosion current between the galvanized layer and the plated original plate is significantly reduced.

その結果、従来の亜鉛メッキ層とメッキ原板との間の腐
食電流が極めて大きく、メッキ欠陥部、あるいは加工時
において生成されるメッキ層の疵付きによる欠陥部或い
は端面がＣ１−イオン含有する腐食環境において亜鉛メ
ッキ層の犠牲防食作用による著しい溶解により、亜鉛メ
ッキ鋼板の耐食性が劣っていたが、本発明のようにＣｒ
含有鋼板を用いることによって解決することができる。As a result, the corrosion current between the conventional galvanized layer and the plated original plate is extremely large, resulting in a corrosive environment containing C1- ions in plating defects, defects in the plating layer due to scratches generated during processing, or edge surfaces. The corrosion resistance of the galvanized steel sheet was poor due to significant dissolution due to the sacrificial anticorrosion effect of the galvanized layer, but as in the present invention, the corrosion resistance of the galvanized steel sheet was poor.
This can be solved by using a steel plate containing steel.

一般に亜鉛系のメッキ層を鋼板に対して如何に厳格に管
理を行なってメッキしても、ピンホール、不メッキ等の
メッキ欠陥を皆無にする事は困難である。Generally, no matter how strictly a zinc-based plating layer is plated on a steel plate, it is difficult to completely eliminate plating defects such as pinholes and non-plating.

従って、本発明の如く、亜鉛メー／キ層とメッキ原板と
の間のカップル腐食電流を著しく減じ、かつメッキ原板
をアノード防食するＣｒを必須成分とする鋼板をメッキ
原板として用いる事によって、メッキ欠陥部や端面部を
アノード防食すると同時に、これら部分の亜鉛系メッキ
層の溶解速度を著しく抑制し、かつ亜鉛系メッキ層が腐
食、消失した後もメッキ原板自体の耐食性によって、極
めて耐食寿命のすぐれた亜鉛系メッキ鋼板が得られる。Therefore, as in the present invention, by using a steel plate as an essential component of Cr, which significantly reduces the couple corrosion current between the zinc make/paint layer and the plated original plate and protects the plated original plate from anodic corrosion, plating defects can be avoided. At the same time as anodic corrosion protection of the parts and end faces, the dissolution rate of the zinc-based plating layer in these parts is significantly suppressed, and even after the zinc-based plating layer corrodes and disappears, the corrosion resistance of the plated original plate itself ensures an extremely long corrosion-resistant life. A galvanized steel sheet is obtained.

さらに、この効果は塗装して使用する場合も、塗膜の経
時後の密着性向上及び塗装後の耐食性向上をもたらす。Furthermore, even when used as a coating, this effect improves the adhesion of the coating film over time and the corrosion resistance after coating.

すなわち、地鉄に達する欠陥部、加工による塗膜表面に
まで達するクラック発生部分或いは塗膜欠陥部等におい
て、亜鉛系メッキ層の犠牲防食能による著しい腐食溶解
を抑制するため、亜鉛の腐食生成物の生成を減少し、塗
膜フクレの生成を防止し、腐食環境に長期に曝された場
合の塗膜剥離を生じにくくさせ、前記の如き欠陥部にお
ける塗料密着性の向上、塗装後耐食性の著しい向上効果
が得られる。而して、こ、れらの効果を得る主要成分の
Ｃｒ含有量の上限は２０％以下に規制される。In other words, in order to suppress significant corrosion and dissolution due to the sacrificial anti-corrosion ability of the zinc-based plating layer, zinc corrosion products are It reduces the formation of paint film, prevents the formation of paint film blisters, makes it difficult for paint film to peel off when exposed to a corrosive environment for a long time, improves paint adhesion in the above-mentioned defective areas, and significantly improves corrosion resistance after painting. An improvement effect can be obtained. Therefore, the upper limit of the Cr content of the main component that provides these effects is regulated to 20% or less.

Ｃｒ含有量が２０％をこえると、上記効果がほぼ飽和す
るとともに、加工性と溶接性が劣化する。特に、成形加
工性の点から、Ｃｒ１１％以下のγ相とα相の変態領域
の組成においては、鋼板製造時において、これらの変態
により結晶粒の粗大化がおこりにくく、苛酷な成形加工
を受けた場合に、リジングと呼ばれるはだ荒れ現象がお
こりにくく好ましい。従って、上記の腐食雰囲気に対す
る耐食性及び加工性、溶接性の面から、Ｃｒ含有量を１
．５〜２０％とした。好ましくは３〜１１％である。When the Cr content exceeds 20%, the above effects are almost saturated and workability and weldability deteriorate. In particular, from the viewpoint of formability, when the composition of the γ-phase and α-phase transformation region is less than 11% Cr, coarsening of crystal grains due to these transformations is less likely to occur during steel plate manufacturing, and it is difficult to undergo harsh forming processes. This is preferable because it is less likely to cause a roughening phenomenon called ridging. Therefore, from the viewpoint of corrosion resistance, workability, and weldability in the above-mentioned corrosive atmosphere, the Cr content was reduced to 1.
．． It was set at 5 to 20%. Preferably it is 3 to 11%.

以上、＃食性の点からはＣｒの効果が最も大きいが、本
発明では自動車用防錆鋼板或いは建築用材料を対象とす
る観点から、Ｃおよび酸可溶Ａｎその他の成分について
も、その含有量を限定する。As mentioned above, Cr has the greatest effect from the viewpoint of #erodibility, but in the present invention, from the viewpoint of targeting rust-proof steel sheets for automobiles or construction materials, the content of C, acid-soluble An, and other components is also determined. limit.

Ｃは含有量の増加につれてクロムカーバイドの析出量が
多くなり、鋼の機械的性質と耐食性を劣化すると同時に
、亜鉛メッキ層の均一被覆性を阻害する。従って、Ｃ含
有量は０．１５％以下、好ましくは０．１θ％以下であ
る。As the C content increases, the amount of chromium carbide precipitated increases, which deteriorates the mechanical properties and corrosion resistance of the steel, and at the same time inhibits the uniform coverage of the galvanized layer. Therefore, the C content is 0.15% or less, preferably 0.1θ% or less.

また、本発明においてＴｉ、Ｎｂ等を添加して、加工性
及び耐食性の向上をさらに図る場合には、Ｃ含有量を０
．０２％以下にするのが、経済性。In addition, in the present invention, when adding Ti, Nb, etc. to further improve workability and corrosion resistance, the C content may be reduced to 0.
．． It is economical to keep it below 0.02%.

加工性、チタンカーバイト等の析出によるメッキ被覆層
の均一被覆性から好ましい。This is preferred from the viewpoint of workability and uniform coverage of the plating layer due to the precipitation of titanium carbide and the like.

Ａ立は、鋼中に残存する酸可溶Ａｌ（Ｓｏ文ＡｆＬ）量
が０．００５％未満の歩合有量は、酸化性ガスによる気
泡の発生を防止する事が困難であり、鋼の表面欠陥発生
率を著しく高め、鋼素材の耐食性劣化の起点となる。ま
た、０．１０％を超える過剰な酸可溶Ａｎは、Ａｌ系酸
化物を鋼表面に点在せしめて、耐食性劣化の起点或いは
本鋼板に対して施されるメッキ面においては不メッキ、
ピンホール等を発生して、メッキ層の健全性を損じる。A: If the amount of acid-soluble Al (So-AfL) remaining in the steel is less than 0.005%, it is difficult to prevent the generation of bubbles due to oxidizing gas, and the surface of the steel It significantly increases the defect occurrence rate and becomes the starting point for deterioration of the corrosion resistance of steel materials. In addition, excessive acid-soluble An exceeding 0.10% causes Al-based oxides to be scattered on the steel surface, which may be the starting point for deterioration of corrosion resistance or may cause unplated surfaces to be applied to the steel sheet.
This causes pinholes, etc., which impairs the integrity of the plating layer.

又、本発明は、上記の鋼成分の他にＴｉ。In addition to the above-mentioned steel components, the present invention also includes Ti.

Ｎｂ、Ｚｒ、Ｖを１種又は２種以上テ０．０３〜０．５
０％を含有させて、鋼中のＣと結合せしめて含有される
Ｃｒの有効化を計り、更にすぐれた成形加工性と、＃食
性を向上せしめる。One or more types of Nb, Zr, and V Te0.03 to 0.5
By including 0% of Cr, Cr is combined with C in the steel to make the contained Cr more effective, further improving formability and eating properties.

Ｔｉなどの鋼成分の含有量が０．０３％未満ではクロム
カーバイドの析出を防止して、成形加工性及び耐食性を
向上せしめる効果が少なく、またその含有量が０．５０
％を超えると、その効果が飽和に達し経済的でなくなる
と共に、これら成分の析出によって素材の硬質化を起し
、成形加工性を劣化する傾向にある。好ましい含有量は
０．０７５〜０．２０％である。If the content of steel components such as Ti is less than 0.03%, the effect of preventing precipitation of chromium carbide and improving formability and corrosion resistance is small;
%, the effect reaches saturation and becomes uneconomical, and the precipitation of these components tends to cause hardening of the material and deteriorate moldability. The preferred content is 0.075-0.20%.

上記のような組成成分で構成された鋼板そのものでは、
耐食性が優れているものの、海風地帯或いは道路凍結防
止用の融雪塩が散布される様な腐食の激しい場所におい
ては、赤錆を発生し、耐食性の劣化が著しい、また、塗
装を施し、耐食４髪向上して使用する用途には、塗料の
密着性向上を計る塗装下地処理の燐酸塩処理が均一に施
され難く、塗装後の性能を著しく劣化する。In the steel plate itself, which is composed of the above composition components,
Although it has excellent corrosion resistance, in areas with severe corrosion such as sea breeze areas or areas where snow melting salt is sprayed to prevent roads from freezing, red rust will occur and the corrosion resistance will deteriorate significantly. In applications where paint is to be used in an improved manner, it is difficult to uniformly apply the phosphate treatment, which is a pre-painting treatment intended to improve the adhesion of the paint, and this significantly deteriorates the performance after painting.

このため、現在自動車用鋼板或いは建築用材料に要求さ
れる耐食性から見れば不充分である。For this reason, it is insufficient in view of the corrosion resistance currently required for automobile steel sheets or building materials.

従って、前記メッキ鋼板により優れた耐食性能、塗装性
能を付与するため、亜鉛系メッキ層を施す。Therefore, in order to impart superior corrosion resistance and coating performance to the plated steel sheet, a zinc-based plating layer is applied.

而して、本発明に使用される、Ｃｒを必須成分として含
有する鋼板に亜鉛系メッキ層を施した場合、従来の鋼板
そのものと比較した場合、亜鉛メッキ層とメッキ原板の
カップル腐食電流が著しく減少する。Therefore, when a zinc-based plating layer is applied to a steel sheet containing Cr as an essential component, which is used in the present invention, when compared with a conventional steel sheet itself, the couple corrosion current between the galvanized layer and the plated original sheet is significantly increased. Decrease.

従って、亜鉛メッキ層の鋼板に対する犠牲防食による腐
食速度が著しく軽減され、腐食環境に曝された場合のメ
ッキ層の腐食量が小さくなる。Therefore, the corrosion rate due to sacrificial corrosion protection of the galvanized steel sheet is significantly reduced, and the amount of corrosion of the galvanized layer when exposed to a corrosive environment is reduced.

従って、従来の、Ｃｒを不可避的不純物程度に含有する
鋼板をメッキ原板にして使用した場合と比較して、本発
明の亜鉛系メッキ鋼板は著しく長期間にわたって鋼板に
対する犠牲防食効果を持続し、その腐食速度も小さく、
耐食性が極めてすぐれたものとなる。Therefore, compared to the conventional case where a steel plate containing Cr as an unavoidable impurity is used as a plating base plate, the zinc-based plated steel plate of the present invention maintains the sacrificial corrosion protection effect on the steel plate for a significantly longer period of time. Corrosion rate is also low,
It has extremely good corrosion resistance.

この結果として、また塗装が施された場合においても１
次の様な利点が得られる。As a result of this, and even when painted, 1
The following advantages can be obtained.

すなわち、塗膜下腐食に対しても、亜鉛系メッキ層の溶
解速度の減少効果により、亜鉛の腐食生成物に基因する
と考えられる塗膜フクレの発生が軽減され、腐食環境に
長期間曝された場合の塗料密着性が著しく改善される。In other words, with regard to under-paint corrosion, the effect of reducing the dissolution rate of the zinc-based plating layer reduces the occurrence of paint blistering, which is thought to be caused by corrosion products of zinc, and prevents long-term exposure to a corrosive environment. Paint adhesion is significantly improved.

特に、地鉄に達する様な塗膜欠陥が生成された場合、或
いは端面等において、従来に比して、塗膜フクレが著し
く軽減され、塗膜」離が著しく少なくなるなどの効果が
得られる。従って、塗膜剥離部分から進行する腐食も著
しく軽減される。In particular, when paint film defects that reach the base metal are generated, or on edge surfaces, etc., compared to conventional methods, paint film blistering is significantly reduced, and paint film peeling is significantly reduced. . Therefore, the corrosion that progresses from the peeled part of the paint film is also significantly reduced.

以上の如く、本発明の亜鉛系メッキ鋼板は、メッキ原板
との粗刻効果とあいまって、メッキ層の腐食速度減少に
よる耐食性向上、塗装性能の向上による耐食性向上によ
り、その耐食寿命は著しく延長される。As described above, the zinc-based plated steel sheet of the present invention has improved corrosion resistance due to a reduction in the corrosion rate of the plated layer, as well as improved coating performance, in combination with the roughening effect with the plated original plate, and its corrosion-resistant life is significantly extended. Ru.

次に１本発明においてメッキ原板に施される亜鉛メッキ
層及び亜鉛系メッキ層は、次のようなメッキ層が好まし
い。Next, in the present invention, the zinc plating layer and the zinc-based plating layer applied to the plated original plate are preferably the following plating layers.

すなわち、メッキ層としては、溶融メッキ法では成形加
工時にメッキ剥離を生じない程度の合金層を有する亜鉛
メッキ層及び電気メツキ法による亜鉛メッキ層が施され
る。また、亜鉛系メッキ層は、５０％以上のＺｎに合金
化元素が混合されたもので、例えば、Ｚ　ｎ−Ａｎ　、
　Ｚｎ−Ａｎ　−５ｉ、Ｚｎ−Ａｌ−Ｓ　ｂ　、　Ｚｎ
−Ａｎ−Ｍｇ系合金メッキ鋼板等が含まれる。That is, as the plating layer, a galvanized layer having an alloy layer to an extent that the plating does not peel off during molding is applied by the hot-dip plating method, and a galvanized layer is applied by the electroplating method. In addition, the zinc-based plating layer is made of 50% or more of Zn mixed with an alloying element, such as Zn-An,
Zn-An-5i, Zn-Al-Sb, Zn
-Includes An-Mg alloy plated steel sheets, etc.

次に、本発明においてメッキは、特に規定されるもので
はなく、鋼板表面を清浄化、活性化処理後、鋼板の片面
又は両面に、溶融メッキ法、電気メ、ギ法、真空蒸着法
等により施される。溶融メッキ法は、ガス還元方式、フ
ラックス方式いずれの方法でもよい。また、電気メツキ
法は、通常用いられる（硫酸亜鉛−硫酸ソーダ　）系水
溶液、或いは（塩化亜鉛−塩化ソーダ　）系水溶液等の
電解浴組成を用いて、亜鉛メッキ層が施される。Next, in the present invention, plating is not particularly specified, and after cleaning and activating the surface of the steel plate, one or both sides of the steel plate may be plated by hot-dip plating, electroplating, vacuum deposition, etc. administered. The hot-dip plating method may be either a gas reduction method or a flux method. Further, in the electroplating method, a galvanized layer is applied using an electrolytic bath composition such as a commonly used (zinc sulfate-sodium sulfate) aqueous solution or (zinc chloride-sodium chloride) aqueous solution.

而して、この亜鉛系メッキ層の厚さは特に規・定されな
いが、均一被覆性の確保による耐食性、耐食寿命の点か
ら、その厚さは１．５牌以上、好ましくは３牌以上のメ
ッキ被膜層が設けられる。また、被覆層の密着性、成形
加工性、溶接性等の面から、その厚さは２５ＪＬ以下、
好ましくは１５色以下の厚さの被覆層が施される。The thickness of this zinc-based plating layer is not particularly specified, but from the viewpoint of corrosion resistance by ensuring uniform coverage and corrosion-resistant life, the thickness should be 1.5 tiles or more, preferably 3 tiles or more. A plated coating layer is provided. In addition, from the viewpoint of adhesion, moldability, weldability, etc. of the coating layer, the thickness should be 25JL or less,
Preferably a coating layer thickness of 15 colors or less is applied.

また、本発明においては、上記の如き鋼組成の原板と亜
鉛系メ・ンキ層との複合効果による耐食性、塗膜性能を
更に向上せしめるために、メッキ原板と亜鉛系メッキ層
との中間層としてＮｉ系下地被覆層が設けられる。In addition, in the present invention, in order to further improve the corrosion resistance and coating performance due to the combined effect of the steel sheet having the above-described steel composition and the zinc-based coating layer, an intermediate layer between the plated sheet and the zinc-based plating layer is used. A Ni-based base coating layer is provided.

このＮｉ系下地被覆１層を設ける事により、Ｚｎ又はＺ
ｎ系合金メッキ層と該下地被覆層との重畳効果によるピ
ンホールの減少による耐食性向上効果が得られる。By providing one layer of this Ni-based base coating, Zn or Z
The effect of improving corrosion resistance is obtained by reducing pinholes due to the superimposed effect of the n-based alloy plating layer and the base coating layer.

また、Ｎｉ系下地被覆層を構成する金属或いは合金は、
亜鉛系メッキ層と比較的拡散速度が速く、塗装焼付は作
業等においてＺｎ−Ｎｉ系合金層が生成易く、地鉄に達
するピンホールの減少による耐食性向上効果も更に得ら
れる。In addition, the metal or alloy constituting the Ni-based base coating layer is
The diffusion rate is relatively fast compared to the zinc-based plating layer, and the Zn--Ni alloy layer is easily formed during paint baking work, etc., and the effect of improving corrosion resistance is also obtained by reducing pinholes that reach the base steel.

而して、このＮｉ系下地被覆層には、Ｎｉ。Therefore, this Ni-based base coating layer contains Ni.

Ｎｉ−Ｃｏ合金、Ｎ１−Ｐ合金、Ｎｉ−Ｆｅ合金、Ｎｆ
拡散処理層が０．０１−１ｇ厚さで設けられる。これ格
は、その厚さが０．０１ｇ未満では、下地被覆層の均一
被覆効果が不足し、上記のピンホール減少効果が得られ
ない傾向にあり、また、その厚さが１牌をこえる場合に
は：上記効果が飽和するとともに、下地被覆層が加工に
より割れを発生する傾向にあり、好ましくないからであ
る。Ni-Co alloy, N1-P alloy, Ni-Fe alloy, Nf
A diffusion treatment layer is provided with a thickness of 0.01-1 g. This is because if the thickness is less than 0.01 g, the uniform coating effect of the base coating layer will be insufficient and the pinhole reduction effect described above will not be obtained, and if the thickness exceeds 1 tile This is because the above effects are saturated and the base coating layer tends to crack due to processing, which is not preferable.

また、これらのＮＪ系下地被覆層のうち、特にＮｉ拡散
被覆層を設ける方法が特にすぐれている。この拡散層は
上記の如き下地被覆層を設けてから冷延鋼板の加熱焼鈍
工程等を活用して拡散処理層が設けられるが、本発明の
鋼成分との複合効果により、メッキ原板表面にＮｉ濃度
の高い電気的に責なメッキ原板となるため、原板自体の
耐食性向−ト効来が得られ、それと同時に１、亜鉛系メ
ッキ層とのカップル腐食電流が減少し、メッキ層のメッ
キ欠陥部や端面部等に対する犠牲溶解による腐食速度が
減少し、その結果として、メッキ鋼板の耐食寿命の延長
、或いは塗装後においても地鉄に達する塗膜欠陥部や端
面等において亜鉛メッキ層等の腐食速度の減少に基づく
、塗膜下腐食が著しく抑制され、塗装後耐食性、経時後
の塗料密着性の向上効果が更に期待できる。Furthermore, among these NJ base coating layers, the method of providing a Ni diffusion coating layer is particularly excellent. This diffusion layer is formed by providing a base coating layer as described above, and then applying a diffusion treatment layer by utilizing a heating annealing process of the cold rolled steel sheet. Due to the combined effect with the steel components of the present invention, Ni Since the plated base plate has a high concentration and is electrically sensitive, the corrosion resistance of the base plate itself is improved.At the same time, the coupled corrosion current with the zinc-based plating layer is reduced, and the plating defects in the plating layer are reduced. As a result, the corrosion resistance of galvanized steel sheets is extended, or even after painting, the corrosion rate of the galvanized layer, etc. is reduced at coating defects that reach the base steel, edge surfaces, etc. Corrosion under the paint film is significantly suppressed due to the reduction in the amount of paint, and further improvements in post-painting corrosion resistance and paint adhesion over time can be expected.

次に、本発明においてメッキ原板に対して施されるＮｉ
系下地被覆層、亜鉛系メッキ層を設ける方法及びその付
着量については、特に規制されるものではないが、その
被覆層を設ける方法につぃては例えば以下の様な方法が
用いられ、また付着量については以下の範囲での使用が
好ましい。Next, in the present invention, Ni is applied to the plated original plate.
There are no particular restrictions on the method of providing the zinc-based base coating layer and the zinc-based plating layer, and the amount of coating thereof; however, for example, the following methods may be used to provide the coating layer. Regarding the amount of adhesion, it is preferable to use it within the following range.

すなわち、Ｎｉ系下地処理法は （１）ニンケル下地処理；硫酸ニッケルー塩化ニッケル
ーホウ酸系浴を用いた電気メッキ法（２）ニッケルーコ
バルト合金下地処理；目的とする組成のニッケル、コバ
ルトイオンを含有する硫酸ニッケルー硫酸コバルト−ｆ
Ｊｌニッケルー塩化コバルト−ホウ酸系浴を用いた電気
メッキ法（３）ニッケルー鉄合金下地処理；目的とする
組成のニッケル、鉄イオンを含有する硫酸ニッケル。That is, the Ni-based base treatment method includes (1) Ni-based base treatment; electroplating method using a nickel sulfate-nickel chloride-boric acid bath; and (2) nickel-cobalt alloy base treatment; containing nickel and cobalt ions of the desired composition. Nickel sulfate-cobalt sulfate-f
Electroplating method using Jl nickel-cobalt chloride-boric acid bath (3) Nickel-iron alloy base treatment; nickel sulfate containing nickel and iron ions having the desired composition.

−硫酸鉄−ホウ酸系浴を用いた電気メッキ法（４）ニッ
ケルーＰ合金下地処理；目的とす−る組成のニッケル、
Ｐイオンを含有する硫酸ニッケルー塩化ニッケルー次亜
リン酸ソーダ　−リン酸系浴を用いた電気メッキ法 等が行なわれる。-Electroplating method using iron sulfate-boric acid bath (4) Nickel-P alloy base treatment; nickel with the desired composition,
An electroplating method using a nickel sulfate-nickel chloride-sodium hypophosphite-phosphoric acid bath containing P ions is performed.

又、Ｎｆ系下地処理法上Ｎｆ系拡散処理層を設ける場合
には、上記のＮｉ及びＮｆ金合金電気メッキ法でメッキ
原板に施すか、或いはＮｉイオン若しくはＮｉイオンと
他の合金化元素イオンを含有する水溶液をメッキ原板表
面に塗布して、各々加熱拡散処理が施される。In addition, when providing an Nf-based diffusion treatment layer on the Nf-based base treatment method, it can be applied to the plated original plate by the above-mentioned Ni and Nf gold alloy electroplating method, or Ni ions or Ni ions and other alloying element ions can be applied to the plated original plate. The aqueous solution containing the plating material is applied to the surface of the plating original plate, and a heating diffusion treatment is applied to each plated original plate.

例えば、上記のＮＬメッキ後或いは酢酸ニッケルー界面
活性剤水溶液、若しくは酢酸ニッケルーリン酸アンモン
ー界面活性剤水溶液をロールコータ−で塗布、乾燥後に
各々非酸化性雰囲気で加熱拡散処理（例えば、６５０〜
９１０°Ｃの温度で３０〜１８０秒間の加熱処理）が行
なわれる。For example, after the above-mentioned NL plating, a nickel acetate-surfactant aqueous solution or a nickel acetate-ammonium phosphate-surfactant aqueous solution is applied with a roll coater, and after drying, heat diffusion treatment (for example, 650 ~
A heat treatment at a temperature of 910° C. for 30 to 180 seconds is carried out.

この拡散被覆層を設ける場合には、冷間圧延のままの鋼
板（Ａｓ　　Ｃｏ立ｄ材）及び冷間圧延後焼鈍された鋼
板（フルフィニッシェ材）のいずれかを用いて、脱脂、
酸洗等の表面清浄化、活性化処理後に電気メッキ法或い
は水溶液塗布法により、Ｎｉ系被覆層を設けて加熱拡散
処理を行なってもよい。しかしながら、冷間圧延のまま
の鋼板にＮｉ系被覆層を設け、原板の焼鈍と同時に拡散
処理を行なうのが、冷間圧延材の有する加工歪により、
Ｎｉ系被覆層と鋼板の相互拡散が一層促進されるので短
時間の加熱処理で目的とする拡散層が生成され、経済的
にも工業的にも有利である。When providing this diffusion coating layer, either a steel plate as cold rolled (As Co standing material) or a steel plate annealed after cold rolling (full finish material) is used to degrease,
After surface cleaning such as pickling and activation treatment, a Ni-based coating layer may be provided by electroplating or aqueous solution coating, and then heat diffusion treatment may be performed. However, it is difficult to provide a Ni-based coating layer on a cold-rolled steel sheet and perform a diffusion treatment at the same time as annealing the original sheet due to the processing strain of the cold-rolled material.
Since the mutual diffusion between the Ni-based coating layer and the steel sheet is further promoted, the desired diffusion layer can be produced in a short heat treatment, which is advantageous both economically and industrially.

而して、これらのＮｉ系地下被覆層は前記したように、
　０．０１−１．０　ｇ、の厚さの被覆層で設けられる
。As mentioned above, these Ni-based underground covering layers
A coating layer with a thickness of 0.01-1.0 g is applied.

以上の様に、本発明の鋼成分を有する鋼板と亜鉛系メッ
キ層、或いはＮｉ系下地層と亜鉛系メッキ層とで構成さ
れているメッキ鋼板は、腐食環境に曝された場合に、メ
ッキ原板とメッキ層の複合効果によってメッキ欠陥、成
形加工時の加工疵部、或いは端面部等においてメッキ層
の犠牲防食作用による溶解速度が軽減される事によって
、メッキ層の耐食寿命が議長され、また、塗装されて使
用される場合には塗膜下腐食の軽減による経時後の塗料
密着性の向上、塗装後耐食性の向上効果が得られる。As described above, a plated steel sheet composed of a steel sheet having the steel components of the present invention and a zinc-based plating layer, or a Ni-based base layer and a zinc-based plating layer, is susceptible to the plated original plate when exposed to a corrosive environment. The combined effect of the plating layer and the plating layer reduces the dissolution rate due to the sacrificial anticorrosive action of the plating layer at plating defects, processing flaws during molding, or end surfaces, etc., thereby extending the corrosion resistance life of the plating layer. When used after being painted, the effects of reducing corrosion under the paint film, improving paint adhesion over time, and improving corrosion resistance after painting can be obtained.

而して、本発明の鋼板を塗装してから使用する場合には
、燐酸塩結晶被膜或いはクロメート処理被膜層が塗装下
地処理として施される。この場合、腐食環境において長
期間曝された場合、腐食水溶液が塗膜下に侵入した場合
において塗装下地処理層が溶解されにくく、塗膜と塗装
下地層との密着性が極めてすぐれた下地被覆層である燐
酸塩結晶被膜を施した場合にすぐれた塗装性能向上効果
が得られる。When the steel sheet of the present invention is used after being painted, a phosphate crystal coating or a chromate treatment coating layer is applied as a base treatment for painting. In this case, the base coating layer is difficult to dissolve when exposed to a corrosive environment for a long period of time or when a corrosive aqueous solution penetrates under the paint film, and the adhesiveness between the paint film and the paint base layer is extremely excellent. When a phosphate crystal coating is applied, an excellent coating performance improvement effect can be obtained.

すなわち、本発明のメッキ鋼板の亜鉛系メッキ層は、前
記したように、メッキ欠陥部、地鉄に達する疵部等にお
ける溶解速度が小さくなるので、腐食水溶液に対して不
溶解性の燐酸塩結晶被膜を塗装下地処理として施しであ
る場合において、従来の亜鉛メッキ鋼板に比して、以下
の如き利点が得られる。In other words, as described above, the zinc-based plating layer of the plated steel sheet of the present invention has a low dissolution rate in plating defects, scratches that reach the base steel, etc., and therefore phosphate crystals that are insoluble in corrosive aqueous solutions. When the coating is applied as a base treatment for painting, the following advantages can be obtained compared to conventional galvanized steel sheets.

亜鉛系メッキ鋼板において、不可避的に生成されるピン
ホール部等に対して、燐酸塩結晶被膜による封孔効果は
あるものの、必ずしも充分でなく、燐酸塩結晶被膜の欠
陥部を侵入した腐食水溶液等によって、メ・ンキ層の欠
陥部に対する亜鉛の犠牲防食作用による溶解速度が大な
るため、従来の亜鉛系メッキ鋼板では塗膜と燐酸塩結晶
被膜の密着性はすぐれているものの、このメッキ層の腐
食部分から塗膜のフクレ、塗膜剥離等が生じる現象がし
ばしばみられた。Although the phosphate crystal coating has a sealing effect on the pinholes that inevitably occur in zinc-based plated steel sheets, it is not always sufficient, and corrosive aqueous solutions, etc. that have penetrated the defective parts of the phosphate crystal coating As a result, the rate of dissolution due to the sacrificial anticorrosive action of zinc on defective parts of the coating layer increases, so although the adhesion between the coating film and the phosphate crystal coating is excellent in conventional zinc-based plated steel sheets, the coating layer Phenomena such as blistering and peeling of the paint film were often observed from the corroded areas.

しかるに、本発明の鋼板においては、メッキ層欠陥に対
する亜鉛の溶解速度が抑制されることにより、塗膜との
密着性が優れている燐酸塩結晶被■りが生成されている
場合に、亜鉛メッキ層の腐食生成物によって燐酸塩被膜
とメッキ層の界面部から塗膜のフクレ、塗膜の剥離等が
極めて減少せしめられる効果が得られる。However, in the steel sheet of the present invention, the rate of dissolution of zinc to defects in the plating layer is suppressed, and when a phosphate crystal covering with excellent adhesion to the coating film is formed, the zinc plating The effect of significantly reducing blistering of the coating film, peeling of the coating film, etc. from the interface between the phosphate coating and the plating layer due to the corrosion products of the layer can be obtained.

従って、塗膜の密着性、経時の密着性及び塗装−後耐食
性が、従来の亜鉛系メッキ鋼板に比して、格段にすぐれ
る。この利点は、地鉄に達する疵付き部或いは端面等に
おいても、同様に、メッキ層の溶解が抑制されるため、
前記と同様の効果が得られ、塗膜の密着性向上、塗装後
耐食性の向上等に対して、極めてすぐれた効果が得られ
る。Therefore, the adhesion of the paint film, the adhesion over time, and the corrosion resistance after painting are much better than those of conventional galvanized steel sheets. This advantage is that dissolution of the plating layer is similarly suppressed even in the flawed parts or end faces that reach the base metal.
The same effects as above can be obtained, and extremely excellent effects can be obtained in improving the adhesion of the coating film, improving the corrosion resistance after painting, etc.

以上の如く、本発明は、塗膜層との密着性がすぐれた燐
酸塩結晶被膜を亜鉛メッキ層表面に施す事によって、亜
鉛メッキ層の過度な犠牲防食作用による亜鉛メッキ層の
腐食が起因する塗膜剥離。As described above, in the present invention, by applying a phosphate crystal coating with excellent adhesion to the coating layer on the surface of the galvanized layer, corrosion of the galvanized layer due to excessive sacrificial corrosion protection of the galvanized layer is prevented. Paint peeling.

塗膜剥離部分の耐食性劣化等が抑制されるので、耐食寿
命の極めて長い塗装鋼板を提供する事ができる。Since deterioration of corrosion resistance in areas where the coating film has peeled off is suppressed, it is possible to provide a coated steel sheet with an extremely long corrosion-resistant life.

（実施例） 以下に、本発明の実施例を比較例とともに説明する。(Example) Examples of the present invention will be described below along with comparative examples.

第１表に示すＣｒ含有量を中心に変化させた鋼成分の鋼
板を用い、下記に示す被覆法により亜鉛系メッキ層或い
はＮｉ系下地被覆層と亜鉛系メッキ層を設けた。A zinc-based plating layer or a Ni-based undercoating layer and a zinc-based plating layer were provided using steel sheets having steel components whose Cr content was mainly varied as shown in Table 1 by the coating method shown below.

すなわち、電気メツキ法による亜鉛メッキ層は、冷延鋼
板（フルフィニツシユ材）を（３％ＮａＯＨ＋０．３％
界面活性剤）系脱脂浴を用い、脱脂、水洗後に１０％Ｈ
２ＳＯ４水溶液を用いて５０　’Ｃテ電流密度２０Ａ／
ｄｍ’で、陽極酸洗１秒、陰極酸洗１秒間づつの電解酸
洗、水洗を行って９表面清浄化、活性化処理を行なった
。その後、（３５Ｃ１７／文の硫酸亜鉛−８０ｇ／立硫
酸ソーダ　）系電解浴を用いて、６０℃、４ＯＡ／ｄｒ
ｒｆの電流密度で所定厚さの亜鉛メッキ層を設けた。In other words, the galvanized layer by electroplating is made by coating a cold-rolled steel plate (full finish material) with (3% NaOH + 0.3%
Using a surfactant-based degreasing bath, 10% H after degreasing and washing with water.
Using 2SO4 aqueous solution at 50'C, current density 20A/
dm', electrolytic pickling was carried out for 1 second each with anodic pickling and cathodic pickling for 1 second, and water washing was carried out to perform 9 surface cleaning and activation treatments. Thereafter, using a (35C17/b zinc sulfate - 80g/sodium sulfate) electrolytic bath, 60℃, 4OA/dr
A galvanized layer of a predetermined thickness was provided at a current density of RF.

一方、溶解メッキ法による亜鉛メッキ層或いは亜鉛系メ
ッキ層については、冷間圧延のままのＡｓＣｏ　ｌｄ材
を用いて、無酸化炉方式による溶融亜鉛メッキ装置を用
いて、Ｚｎ−０，２％Ａｎ系メッキ浴及び第１表に示す
亜鉛合金メッキ浴を用いて、各々所定厚さの亜鉛系メッ
キ層を設けた。On the other hand, for the galvanized layer or zinc-based plating layer formed by hot-dip plating, cold-rolled AsCold material is used, and a Zn-0.2% An A zinc-based plating layer of a predetermined thickness was provided using each of the zinc-based plating baths and the zinc alloy plating baths shown in Table 1.

ざらに、Ｎｉ系下地被榎層を設ける場合においては、電
気メツ本坊による下地被Ｎ層の場合には前記の電気メツ
キ法と同一方法で、Ｎｉ系の電解浴組成を用いて所定厚
さのＮｉ系下地被覆層を施して亜鉛系メッキ層を設けた
。Ｎｉ系拡散被覆層の場合には、Ａｓ　Ｃｏ１ｄ材を用
い、その表面を電気メッキの場合と同方法で洗浄、活性
化後に溶融メッキにおける無酸化炉を用いて、加熱拡散
をＡｓＣｏ　ｌｄ材の焼鈍と同時に行って拡散層を設け
た。Generally speaking, when providing a Ni-based undercoating layer, in the case of an N-layer undercoating by electric plating, a predetermined thickness is formed by using the same method as the electroplating method described above using a Ni-based electrolytic bath composition. A Ni-based base coating layer was applied to provide a zinc-based plating layer. In the case of a Ni-based diffusion coating layer, use As Cold material, and after cleaning and activating the surface using the same method as in the case of electroplating, use a non-oxidizing furnace in hot-dip plating to perform heating diffusion by annealing the As Cold material. At the same time, a diffusion layer was provided.

而して、その後亜鉛系メッキ層を施した。その後、無処
理材のまま或いはＣｒＯ３−５ｉ０２系浴を用いたクロ
メート処理及びフルディップ型式の燐酸塩処理を行なっ
て、各々所定の被膜量を設けて、下記の評価試験を行な
った。Then, a zinc-based plating layer was applied. Thereafter, the untreated material was left untreated, or a chromate treatment using a CrO3-5i02 bath and a full-dip type phosphate treatment were performed to provide a predetermined coating amount for each, and the following evaluation tests were conducted.

その性能評価試験結果は第２表に示・されるように、本
発明°の鋼板は比較例鋼板に比して、耐食性能及び塗装
性能において極めてすぐれた特性を有する。As shown in Table 2, the performance evaluation test results show that the steel sheet of the present invention has extremely superior corrosion resistance and coating performance compared to the steel sheet of the comparative example.

Ｏ評価試験法 （Ｉ）無塗装材の耐食性 ■　塩水噴霧試験による耐食性 塩水噴霧試験２４０時間後の赤錆発生 率の測定により、ノー２キ欠陥部に起因して発生する赤
錆発生状況からその耐食性の評価を行なった。O evaluation test method (I) Corrosion resistance of unpainted materials ■ Corrosion resistance by salt spray test By measuring the incidence of red rust after 240 hours of the salt spray test, the corrosion resistance was evaluated based on the red rust occurrence caused by the no-2-ki defects. We conducted an evaluation.

■・・・・・・赤錆発生率３％未満 Ｏ・・・・・・　　ｔｔ　　　３％以上〜１０％未満Δ
・・・・・・　　ｔｔ　　　１０％以上〜３０％未満×
・・・・・・ｔｔ　　　　　３０％以上■　サイクリッ
クコロジョンテストによる耐食性 ０．８　ｍｍ板厚の評価材を用いて、 （１）塩水噴Ｎ（５％ＮａＣ文　３５℃×４時間）−＋
ｆｉ）乾燥（７０℃　湿度６０％２時間）→’ｉｉン湿
潤（４９°Ｃ湿度９８％　２時間）→　冷却（−２０℃
×２時間）→中塩水噴霧（（１）〜　が１サイクル） の条件のサイクリックコロジョンテスト５０サイクル後
の穿孔腐食深さの測定により、以下の評価基準で耐食性
評価を行なった。■・・・Red rust occurrence rate less than 3% O・・・・・・ tt 3% or more to less than 10% Δ
・・・・・・ tt 10% or more - less than 30%×
・・・・・・tt 30% or more ■ Corrosion resistance by cyclic corrosion test Using a plate thickness of 0.8 mm, (1) Salt water spray N (5% NaC, 35°C x 4 hours) -+
fi) Drying (70°C, humidity 60%, 2 hours) → Humidity (49°C, humidity 98%, 2 hours) → Cooling (-20°C
Corrosion resistance was evaluated using the following evaluation criteria by measuring the depth of perforation corrosion after 50 cycles of a cyclic corrosion test under the following conditions: x 2 hours) → medium salt water spray ((1) to 1 cycle).

■・・・・・・最大穿孔腐食深さ０．３　ｌ１ｍ未満０
・・・・・・　　ｔｔ　　’　　　　　０．３ｍ１ｓ以
上〜０．４５１ｍ未満 △・・・・・・　　／／　　　　　　　０．４５１１１
１以上〜０．８０ｍｍ未満 ×・・・・・・　　ｔｔ　　　　　　　０　、６０　ｍ
−以上〜孔明き発生 ■　屋外曝露試験による耐食性 ０．８■板厚の評価材を用い５％ＮａＣ１水を１回／１
日評価材に散布して、２年間の屋外曝露テストを実施し
た後、その穿孔腐食深さ測定及び評価材の端面からの腐
食状況を観察して、以下の評価基準によりその耐食性を
評価した。■・・・Maximum drilling corrosion depth 0.3 less than 1m0
・・・・・・ tt ' 0.3m1s or more ~ less than 0.451m △・・・・・・ // 0.45111
1 or more - less than 0.80 mm × tt 0, 60 m
- or more - pitting occurred ■ Corrosion resistance by outdoor exposure test: 0.8 ■ Use 5% NaCl water once/1 time using evaluation material with board thickness
After spraying it on the evaluation material and conducting an outdoor exposure test for 2 years, the depth of perforation corrosion was measured and the corrosion situation from the end surface of the evaluation material was observed, and the corrosion resistance was evaluated according to the following evaluation criteria.

■・・・・・・最大穿孔深さ０．２５！Ｉ１ｍ未満で、
端面部からの腐食殆んどなし Ｏ・・・・・・最大穿孔腐食深さ０．２５ｍｍ以上〜０
．４０ｍｍ未満で、端面部からの腐食若干発生 Δ・・・・・・最大穿孔腐食深さ０．４ｈａ以北〜０．
６０ｍｍ未満で、端面部からの腐食が可成り発生 ×・・・・・・最大穿孔腐食深さ０．８０ｍｍ以上〜部
分的に孔食発生、また端面部から の腐食により端面の初期の形状殆 んどなし く　ＴＩ　）塗装材の耐食性 ■　塩水噴霧試験後の塗装性能 カチオン電着により、２０．厚さの塗 装を行ない、地鉄に達するスクラッチ疵を入れて、塩水
噴霧試験３００時間後の塗膜のフクレ発生状況及びスク
ラッチ部の最大穿孔腐食深さの測定を行なって、塗膜欠
陥部を対象とした経時後の塗料密着性及び塗装後耐食性
の評価を行なっ た。■・・・Maximum drilling depth 0.25! I less than 1m,
Almost no corrosion from the end face O... Maximum drilling corrosion depth 0.25 mm or more ~ 0
．． Less than 40 mm, slight corrosion occurs from the end surface Δ... Maximum drilling corrosion depth north of 0.4 ha ~ 0.
If the depth is less than 60mm, corrosion from the end face will occur considerably. TI) Corrosion resistance of coating materials ■ Coating performance after salt spray test 20. After 300 hours of a salt spray test, we measured the occurrence of blistering in the paint film and the maximum perforation corrosion depth in the scratched area to remove the defective parts of the paint film. The paint adhesion and corrosion resistance after painting were evaluated.

尚、評価基準は以下の方法によった。In addition, the evaluation criteria were based on the following method.

■・・・・・・スクラッチ部からの片側最大フクレ巾３
．５１以下でかつ最大穿孔腐 食深さ０．１ａｍ以下 さ０．２ｍｍ以下 Δ・・・・・・スクラッチ部からの片側最大フクレ巾７
．５■以下でかつ最大穿孔腐 食深さ０．３■以下 ×・・・・・・スクラッチ部からの片側最大フクレ巾７
．５ｍｍ超又は最大穿孔腐食深 さ０．２ｍｍ　ｍ ■　サイクリックコロジョンテストによる塗装性能 カチオン電着塗装材（塗膜厚さ１８ 、Ｌ）を用いて、地鉄に達するスフランチ疵を入れて前
記（■項の条件のサイクリックコロジョンテスト１００
サイクル後のスクラッチ部の塗膜フクレ巾及びスク ラッチ部の最大穿孔腐食深さの測定を行ない、塗膜欠陥
部を対象として、その経時後の塗料密着性及び塗装後耐
食性を中心とした評価を行なった。尚、評価基準は以下
に示す方法によった。■・・・Maximum bulge width on one side from scratch part 3
．． 51 or less and the maximum drilling corrosion depth is 0.1 am or less and 0.2 mm or less Δ...Maximum blistering width on one side from the scratch part 7
．． 5 ■ or less and maximum drilling corrosion depth of 0.3 ■ or less
．． More than 5 mm or maximum perforation corrosion depth 0.2 mm ■ Coating performance by cyclic corrosion test Using a cationic electrodeposition coating material (coating film thickness 18 mm, L), create a spanch scratch that reaches the base steel and perform the above ( Cyclic corrosion test 100 under the conditions of section ■
After the cycle, the width of the paint film blistering in the scratched area and the maximum depth of perforation corrosion in the scratched area were measured, and the defective parts of the paint film were evaluated focusing on the paint adhesion over time and the corrosion resistance after painting. Ta. Note that the evaluation criteria were based on the method shown below.

■・・・・・・スクラッチ部からの片側最大フクレ巾５
■以下で、かつ最大穿孔屑 食深さ０．１ｍｍ以下 食深さ０．２＋＋＊以下 Δ・・・・・・スクラッチ部からの片側最大フクレ巾８
．５ａｍ以下で、かつ最大穿孔 腐食深さ０．３ｍｍ以下 Ｘ・・・・・・スクラッチ部からの片側最大フクレ巾８
．５ｉｍ超又は最大穿孔腐食深 さ０．３ｍｍ　ｊｆｌ ＋ｊ）　　端面部のサイクリックコロジョンテストによ
る耐食性 ０．８）板厚の２０ｇ厚さのカチオン電着材を用いて、
前記■項のサイクリ、クコロジョンテスト条件で７５サ
イクル後の端面部の赤錆発生状況の観察を行なって、端
面部のメッキ層の腐食状況、塗膜性能を表わす一つの尺
度として、その評価を行なった。■・・・Maximum blistering width on one side from scratch part 5
■ Maximum drilling debris corrosion depth: 0.1 mm or less; corrosion depth: 0.2++* or less Δ...Maximum blistering width on one side from the scratch area: 8
．． 5am or less, and the maximum drilling corrosion depth is 0.3mm or less
．． More than 5im or maximum drilling corrosion depth 0.3mm jfl +j) Corrosion resistance by cyclic corrosion test of end face 0.8) Using cationic electrodeposition material with a thickness of 20g of the plate thickness,
We observed the occurrence of red rust on the end face after 75 cycles under the cycle and corrosion test conditions described in item (2) above, and evaluated it as a measure to express the corrosion state of the plating layer on the end face and the coating film performance. I did it.

０・・・・・・赤錆発生率２０％未満 Ｏ・・・・・・　　ｌ／２０％以上〜４０％未満Δ・・
・・・・　　〃４０％以上〜６０％未満×・・・・・・
　　ｌ／６０％以上 ■　成形加工性 ０．８＋ａｍ　Ｘ４８０Ｘ４８０ｍｍのブランクサイズ
から、しわ押え圧力２０Ｔで、 ２００Ｘ２０Ｏｍｍサイズ、絞り深さ １１０ｍｍの角筒絞りを行ない、その割れ発生状況、表
面の“ハダ荒れ”　（リジング）発生状況を相対に比較
して、その成形加工性を評価した。0... Red rust occurrence rate less than 20% O... l/20% or more to less than 40% Δ...
・・・・・・〃40% or more - less than 60%×・・・・・・
l/60% or more ■ Forming processability 0.8+am From a blank size of The molding processability was evaluated by comparing the relative occurrence of ridging.

■・・・・・・非常にすぐれてｌ、％るＯ・・・・・・
可成り良好 Δ・・・・・・可成り劣る Ｘ・・・・・・非常に劣る Ｚｎメッキしたときの５％ＮａＣ文水溶液中におけるカ
ップル腐食電流示すグラフである。■・・・・・・Excellent l,%ruO・・・・・・
Fairly good Δ...fairly poor

代理人　弁理士　　秋　沢　政　光 外２名Agent Patent Attorney Masaaki Aki Sawa 2 people outside

Claims (4)

【特許請求の範囲】[Claims] （１）重量％で、 Ｃ；０．１５％以下、酸可溶Ａｌ；０．００５〜０．１
０％、Ｃｒ：１．５〜２０％を含有する鋼板の片面又は
両面に、亜鉛メッキ層或いは亜鉛系メッキ層を施してな
る耐食性及び塗装性にすぐれた亜鉛系メッキ鋼板。(1) In weight%, C: 0.15% or less, acid-soluble Al: 0.005 to 0.1
A zinc-plated steel sheet with excellent corrosion resistance and paintability, which is obtained by applying a zinc plating layer or a zinc-based plating layer to one or both sides of a steel sheet containing 0% Cr and 1.5 to 20% Cr. （２）重量％で、 Ｃ：０．１５％以下、酸可溶Ａｌ；０．００５〜０．１
０％、Ｃｒ；１．５〜２０％、にＴｉ、Ｎｂ、Ｖ、Ｚｒ
の１種又は２種以上で０．０３〜０．５０％を含有する
鋼板の片面又は両面に、亜鉛メッキ層或いは亜鉛系メッ
キ層を施してなる耐食性及び塗装性にすぐれた亜鉛系メ
ッキ鋼板。(2) In weight%, C: 0.15% or less, acid-soluble Al: 0.005 to 0.1
0%, Cr; 1.5-20%, Ti, Nb, V, Zr
A zinc-plated steel sheet with excellent corrosion resistance and paintability, which is obtained by applying a galvanized layer or a zinc-based plating layer to one or both sides of a steel sheet containing 0.03 to 0.50% of one or more of the following. （３）重量％で、 Ｃ：０．１５％以下、酸可溶Ａｌ；０．００５〜０．１
０％、Ｃｒ；１．５〜２０％、を含有する鋼板の片面又
は両面に、Ｎｉ系下地被覆層と亜鉛メッキ層或いは亜鉛
系メッキ層を施してなる耐食性及び塗装性にすぐれた亜
鉛系メッキ鋼板。(3) In weight%, C: 0.15% or less, acid-soluble Al: 0.005 to 0.1
Zinc-based plating with excellent corrosion resistance and paintability, which is obtained by applying a Ni-based base coating layer and a zinc plating layer or a zinc-based plating layer to one or both sides of a steel plate containing 0% Cr; 1.5 to 20%. steel plate. （４）重量％で、 Ｃ：０．１５％以下、酸可溶Ａｌ；０．００５〜０．１
０％、Ｃｒ；１．５〜２０％、にＴｉ、Ｎｂ、Ｖ、Ｚｒ
の１種又は２種以上で０．０３〜０．５０％を含有する
鋼板の片面又は両面に、Ｎｉ系下地被覆層と亜鉛メッキ
層或いは亜鉛系メッキ層を施してなる耐食性と塗装性に
すぐれた亜鉛系メッキ鋼板。(4) In weight%, C: 0.15% or less, acid-soluble Al: 0.005 to 0.1
0%, Cr; 1.5-20%, Ti, Nb, V, Zr
A steel sheet containing 0.03 to 0.50% of one or more of Galvanized steel sheet.