JP2707085B2 - Zinc-chromium composite electroplated steel sheet - Google Patents
Zinc-chromium composite electroplated steel sheetInfo
- Publication number
- JP2707085B2 JP2707085B2 JP62195343A JP19534387A JP2707085B2 JP 2707085 B2 JP2707085 B2 JP 2707085B2 JP 62195343 A JP62195343 A JP 62195343A JP 19534387 A JP19534387 A JP 19534387A JP 2707085 B2 JP2707085 B2 JP 2707085B2
- Authority
- JP
- Japan
- Prior art keywords
- zinc
- steel sheet
- plating
- electroplated steel
- metal oxide
- 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.)
- Expired - Lifetime
Links
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、亜鉛−クロム系複合電気めっき鋼板に関す
るものである。
詳しくは例えば、自動車、建材、電機製品等に使用さ
れる防錆鋼板の耐食性を向上せしめた、めっき鋼板に関
するものである。
（従来技術）
亜鉛系電気めっき鋼板のめっき層中にAl2O3,SiO2等の
酸化物コロイドを分散共析し、めっき金属と酸化物によ
って、耐食性を向上させることが知られている（例え
ば、特開昭61−127900、61−270398、61−235600、61−
266598等）。
このようなめっき鋼板においては、酸化物微粒子が、
マトリックスとしてのめっき金属が腐食するときの、バ
リアーとなることから耐食性が向上するものとみられて
いた。
（発明の解決しようとする問題点）
しかるに、このようなめっき鋼板の耐食性試験による
と、その効果は微々たるもので、到底工業的に採用でき
る程の耐食性向上はみられず、更に耐食性を向上させる
べく開発が強く要求されているところである。
また、亜鉛系めっき層中にCrを共析させると耐食性が
向上することも知られている（例えば、特公昭61−3607
8、特開昭61−270938等）。
しかし、Crの含有量は極めて微量であって、Crの耐食
性向上効果は付随的でしかあり得ない。Crは亜鉛めっき
中に極めて電着し難く、Zn−Cr合金電気めっきを工業的
に製造できる技術が伴なわなかったためである。
（問題点を解決するための手段）
本発明の特徴とするところは、
（１）金属酸化物粒子0.2〜20％、Cr5超〜40％、残亜鉛
からなり、更に該金属酸化物がSi,Zr,Ti,Sb,Sn,Cr,Mo,C
eの酸化物の１種以上からなり、めっき層中に該金属酸
化物粒子が分散析出した、亜鉛−クロム系複合電気めっ
き鋼板。
（２）金属酸化物粒子0.2〜20％、Cr5超〜40％、残亜鉛
からなり、更に該金属酸化物がSi,Zr,Ti,Sb,Sn,Cr,Mo,C
eの酸化物の１種以上からなり、めっき層中に該金属酸
化物粒子が分散析出した、亜鉛−クロム系複合電気めっ
き鋼板上に鉄:60％以上、残亜鉛からなる鉄−亜鉛系電
気めっき層を生成せしめた亜鉛−クロム系複合電気めっ
き鋼板。
に関するものである。
（作 用）
先ずCrの作用について説明する。CrはZnと共存下では
不働能化せず、活性状態を維持するので、Znとともに鋼
素地に対する犠牲防食作用に加担する。更に、Crの腐食
生成物はZnと異なり、極めて難溶性の保護被膜を腐食部
に堆積するので、耐食性が大巾に向上するものと考えて
いる。
しかしながら、例えば、Si,Zr,Ti,Sb,Sn,Cr,Mo,Ceの
金属酸化物微粒子がめっき層中に分散していると、更に
耐食性が向上することが認められた。これらの微粒子表
面でCrの腐食生成物を固定し、錆の保護性を更に強化し
ているものと考えられる。
めっき層中のCr含有量は５超〜40％が好ましく、７〜
30％が特に好ましい。５％以下であれば、若干の効果は
認められるものの、白錆発生する傾向は残り、耐食性は
十分ではない。５％超になると、例えば塩水噴霧試験等
では白錆発生が抑制され、効果が顕著に認められる。
更に７％以上になると、ほとんど赤錆の発生はなく、
画期的な効果が得られ、腐食電位も貴側に移行してくる
ので、Crの効果が確実に得られる。30％超になると耐食
性向上効果は飽和傾向を示し、40％を超えても耐食性効
果は認められるが、加工時にめっき剥離が起り易くな
り、実用上は好ましくない。
Si,Zr,Ti,Sb,Sn,Cr,Mo,Ceの酸化物微粒子は、１種ま
たは２種以上合計の含有量として0.2〜20％が好まし
い。0.2％未満ではほとんど耐食性向上効果は認められ
ない。0.2％以上で錆発生の耐久時間を延ばす効果が認
められる。20％を超えると、効果は飽和し、更に添加す
る必要性はなく、加工時のめっき剥離の危険性が高まる
ので好ましくない。
酸化物微粒子としては粒径１μｍ以下のコロイドを用
いるのが好ましく、かくすることにより、めっき層中に
均一に分散共析できる。
なお、残部はZnからなるものであるが、更にNi,Co,F
e,Mn,Cu,Sn,Pb,Cd,P,Na,Mg,C,S等を不可避的に含有して
もよい。
次に製造態様について説明する。
Zn2+イオン、Cr3+イオン10〜70g/およびSi,Zr,Ti,S
b,Sn,Cr,Mo,Ceの酸化物コロイドの１種または２種以上
を２〜200g/含む酸性めっき浴から、電流密度70〜250
A/dm2でめっきすることにより、本発明のめっき鋼板が
製造できる。
従来Zn−Crの共析が困難であったが、上記酸化物コロ
イド存在下で、高電流密度でめっきすることにより、５
％超のCrの共析が可能となった。
リン酸塩処理、カチオン電着塗装用にする場合には、
上記めっき層上に鉄60％以上、残亜鉛からなる電気めっ
き層を生成させることにより、カチオン電着塗装時のク
レーター状の塗膜欠陥発生を防止し、かつ塗装密着性の
優れたリン酸亜鉛鉄皮膜を形成できる。
このような上層のめっき層にNi,Cr,Al,P,Cu,Co,Cd等
を含有させることもでき、上層めっき量としては１〜10
g/m2が適当である。又、前記下層メッキ量としては10〜
50g/m2で十分耐食性等を確保することができる。
（実施例）
次に本発明の実施例を比較例とともに第１表、第２表
に挙げる。
注１）
下層めっき条件はZn2+イオン:43g/、Cr3+イオン:15
g/、Na+イオン:18g/を硫酸塩として建浴、SiO2コロ
イド:19g/からなる、pH＝2.0、50℃のめっき浴を用い
て、冷延鋼板（0.6mm厚）に、めっき液流速60m/min、電
流密度150A/dm2で実施例１のめっき鋼板を製造し、他の
実施例及び比較例はそれぞれ条件を変えて製造した。
注２）
上層めっき条件は周知の条件でめっきを施した。
このようにして製造した亜鉛−クロム複合電気めっき
鋼板を次記のごとく評価した。
（発明の効果）
かくすることにより、耐食性の優れた防錆鋼板が得ら
れる。Description: TECHNICAL FIELD The present invention relates to a zinc-chromium composite electroplated steel sheet. More specifically, for example, the present invention relates to a plated steel sheet having improved corrosion resistance of a rustproof steel sheet used for automobiles, building materials, electric products, and the like. (Prior art) It is known that colloidal oxides such as Al 2 O 3 and SiO 2 are dispersed and eutectoid in a plating layer of a zinc-based electroplated steel sheet, and the corrosion resistance is improved by a plating metal and an oxide ( For example, JP-A-61-127900, 61-270398, 61-235600, 61-
266598 etc.). In such a plated steel sheet, the oxide fine particles contain
It has been considered that the corrosion resistance is improved because it serves as a barrier when the plating metal as a matrix corrodes. (Problems to be Solved by the Invention) However, according to the corrosion resistance test of such a plated steel sheet, the effect is insignificant, and the corrosion resistance is not improved enough to be industrially adopted, and the corrosion resistance is further improved. There is a strong demand for development. It is also known that the corrosion resistance is improved when Cr is eutectoid in a zinc-based plating layer (for example, JP-B-61-3607).
8, JP-A-61-270938). However, the content of Cr is extremely small, and the effect of improving the corrosion resistance of Cr can only be incidental. This is because Cr is extremely difficult to electrodeposit during galvanization, and there is no technology for industrially producing Zn-Cr alloy electroplating. (Means for Solving the Problems) The features of the present invention are as follows: (1) Metal oxide particles are composed of 0.2 to 20%, Cr5 to 40%, and residual zinc. Zr, Ti, Sb, Sn, Cr, Mo, C
A zinc-chromium composite electroplated steel sheet comprising at least one oxide of e, wherein the metal oxide particles are dispersed and precipitated in a plating layer. (2) Metal oxide particles 0.2 to 20%, Cr5 to 40%, residual zinc, and the metal oxide is Si, Zr, Ti, Sb, Sn, Cr, Mo, C
e: 60% or more of iron on a zinc-chromium-based composite electroplated steel sheet comprising at least one oxide of e, wherein the metal oxide particles are dispersed and precipitated in a plating layer, and iron-zinc-based electricity comprising residual zinc. A zinc-chromium composite electroplated steel sheet with a plated layer formed. It is about. (Operation) First, the effect of Cr will be described. Cr does not passivate in the coexistence with Zn and maintains an active state, so that together with Zn, it contributes to the sacrificial anticorrosion action on the steel substrate. Further, unlike the case of Zn, the corrosion product of Cr deposits a very hardly soluble protective coating on the corroded portion, so that it is considered that the corrosion resistance is greatly improved. However, it was recognized that, for example, when the metal oxide fine particles of Si, Zr, Ti, Sb, Sn, Cr, Mo, and Ce were dispersed in the plating layer, the corrosion resistance was further improved. It is considered that the corrosion products of Cr are fixed on the surface of these fine particles, and the protection of rust is further enhanced. The Cr content in the plating layer is preferably more than 5 to 40%, and 7 to
30% is particularly preferred. If it is 5% or less, although a slight effect is recognized, the tendency to generate white rust remains, and the corrosion resistance is not sufficient. When it exceeds 5%, for example, in a salt spray test or the like, the generation of white rust is suppressed, and the effect is remarkably recognized. When it becomes 7% or more, there is almost no red rust,
An epoch-making effect is obtained, and the corrosion potential shifts to the noble side, so that the effect of Cr is reliably obtained. If it exceeds 30%, the effect of improving corrosion resistance tends to be saturated, and if it exceeds 40%, the effect of corrosion resistance is recognized, but plating peeling tends to occur during processing, which is not preferable in practical use. The content of the oxide fine particles of Si, Zr, Ti, Sb, Sn, Cr, Mo, and Ce is preferably 0.2 to 20% as a total content of one or more of them. If it is less than 0.2%, the effect of improving corrosion resistance is hardly recognized. At 0.2% or more, the effect of extending the durability time of rust generation is recognized. If it exceeds 20%, the effect is saturated and there is no need to further add it, and the risk of plating peeling during processing increases, which is not preferable. As the oxide fine particles, it is preferable to use a colloid having a particle size of 1 μm or less. By doing so, it is possible to uniformly disperse and codeposit in the plating layer. The balance is made of Zn, but Ni, Co, F
e, Mn, Cu, Sn, Pb, Cd, P, Na, Mg, C, S and the like may be inevitably contained. Next, a manufacturing mode will be described. Zn 2+ ion, Cr 3+ ion 10 to 70 g / and Si, Zr, Ti, S
A current density of 70 to 250 was obtained from an acidic plating bath containing 2 to 200 g / b of one or more oxide colloids of b, Sn, Cr, Mo, and Ce.
By plating with A / dm 2, plating steel sheet of the present invention can be manufactured. Conventionally, it has been difficult to codeposit Zn-Cr, but by plating at a high current density in the presence of the oxide colloid,
% Of eutectoid Cr was made possible. For phosphate treatment and cationic electrodeposition coating,
By forming an electroplating layer composed of at least 60% iron and remaining zinc on the plating layer, crater-like coating film defects during cationic electrodeposition coating are prevented, and zinc phosphate excellent in coating adhesion is provided. An iron film can be formed. Such an upper plating layer may contain Ni, Cr, Al, P, Cu, Co, Cd, etc., and the upper plating amount is 1 to 10
g / m 2 is appropriate. Also, the lower layer plating amount is 10 to
50 g / m 2 can sufficiently secure corrosion resistance and the like. (Examples) Next, Examples of the present invention are listed in Tables 1 and 2 together with Comparative Examples. Note 1) Lower plating conditions: Zn 2+ ion: 43 g / Cr 3+ ion: 15
g /, Na + ion: 18g / as sulfate, SiO 2 colloid: 19g /, using a plating bath of pH = 2.0, 50 ° C, plating solution on cold rolled steel sheet (0.6mm thickness) The plated steel sheet of Example 1 was manufactured at a flow rate of 60 m / min and a current density of 150 A / dm 2 , and the other Examples and Comparative Examples were manufactured under different conditions. Note 2) Plating was performed under well-known plating conditions. The zinc-chromium composite electroplated steel sheet thus manufactured was evaluated as described below. (Effect of the Invention) By doing so, a rustproof steel sheet having excellent corrosion resistance can be obtained.
フロントページの続き (72)発明者 新井 勝利 愛知県東海市東海町５―３ 新日本製鐵 株式会社名古屋製鐵所内 (72)発明者 鈴木 真一 愛知県東海市東海町５―３ 新日本製鐵 株式会社名古屋製鐵所内 (56)参考文献 特開 昭60−125395（ＪＰ，Ａ) 特開 昭56−133488（ＪＰ，Ａ) 特開 昭62−48539（ＪＰ，Ａ) 特開 昭55−58386（ＪＰ，Ａ) 特許2562607（ＪＰ，Ｂ２) 特公 平２−51996（ＪＰ，Ｂ２)Continuation of front page (72) Inventor Masaru Arai 5-3 Tokai-cho, Tokai City, Aichi Prefecture Nippon Steel Corporation Nagoya Works, Ltd. (72) Inventor Shinichi Suzuki 5-3 Tokai-cho, Tokai City, Aichi Prefecture Nippon Steel Corporation Nagoya Works, Ltd. (56) References JP-A-60-125395 (JP, A) JP-A-56-133488 (JP, A) JP-A-62-48539 (JP, A) JP-A-55-58386 (JP, A) Patent 2562607 (JP, B2) Tokiko Hei 2-51996 (JP, B2)
Claims (1)
らなり、更に該金属酸化物がSi,Zr,Ti,Sb,Sn,Cr,Mo,Ce
の酸化物の１種以上からなり、めっき層中に該金属酸化
物粒子が分散析出した、亜鉛−クロム系複合電気めっき
鋼板。 ２．金属酸化物粒子0.2〜20％、Cr5超〜40％、残亜鉛か
らなり、更に該金属酸化物がSi,Zr,Ti,Sb,Sn,Cr,Mo,Ce
の酸化物の１種以上からなり、めっき層中に該金属酸化
物粒子が分散析出した、亜鉛−クロム系複合電気めっき
鋼板上に、鉄:60％以上、残亜鉛からなる鉄−亜鉛系電
気めっき層を生成せしめた亜鉛−クロム系複合電気めっ
き鋼板。(57) [Claims] 0.2-20% of metal oxide particles, more than 40% of Cr5, residual zinc, and the metal oxide is Si, Zr, Ti, Sb, Sn, Cr, Mo, Ce
A zinc-chromium composite electroplated steel sheet comprising at least one oxide of the above, wherein the metal oxide particles are dispersed and precipitated in a plating layer. 2. 0.2-20% of metal oxide particles, more than 40% of Cr5, residual zinc, and the metal oxide is Si, Zr, Ti, Sb, Sn, Cr, Mo, Ce
On a zinc-chromium-based composite electroplated steel sheet comprising at least one oxide of the following, wherein the metal oxide particles are dispersed and precipitated in a plating layer: iron: 60% or more; A zinc-chromium composite electroplated steel sheet with a plated layer formed.
Priority Applications (11)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62195343A JP2707085B2 (en) | 1987-08-06 | 1987-08-06 | Zinc-chromium composite electroplated steel sheet |
| EP88104874A EP0285931B1 (en) | 1987-03-31 | 1988-03-25 | Corrosion resistant plated steel strip and method for producing same |
| DE88104874T DE3882769T2 (en) | 1987-03-31 | 1988-03-25 | Corrosion-resistant plated steel strip and process for its manufacture. |
| US07/174,830 US4897317A (en) | 1987-03-31 | 1988-03-29 | Corrosion resistant Zn-Cr plated steel strip |
| CA000562971A CA1336698C (en) | 1987-03-31 | 1988-03-30 | Corrosion resistant plated steel strip and method for producing same |
| AU13897/88A AU597163B2 (en) | 1987-03-31 | 1988-03-30 | Corrosion resistant plated steel strip and method for producing same |
| KR1019880003622A KR910002186B1 (en) | 1987-03-31 | 1988-03-31 | Corrosion resistant zn-cr plated steel strip |
| US07/320,071 US4877494A (en) | 1987-03-31 | 1989-03-07 | Corrosion resistant plated steel strip and method for producing same |
| CA000616732A CA1336700C (en) | 1987-03-31 | 1993-09-21 | Corrosion resistant plated steel strip and method for producing same |
| CA000616731A CA1336699C (en) | 1987-03-31 | 1993-09-21 | Corrosion resistant plated steel strip and method for producing same |
| CA000616830A CA1337054C (en) | 1987-03-31 | 1994-03-07 | Corrosion resistant plated steel strip and method for producing same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62195343A JP2707085B2 (en) | 1987-08-06 | 1987-08-06 | Zinc-chromium composite electroplated steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6439398A JPS6439398A (en) | 1989-02-09 |
| JP2707085B2 true JP2707085B2 (en) | 1998-01-28 |
Family
ID=16339590
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62195343A Expired - Lifetime JP2707085B2 (en) | 1987-03-31 | 1987-08-06 | Zinc-chromium composite electroplated steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2707085B2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2562607B2 (en) | 1987-08-06 | 1996-12-11 | 新日本製鐵株式会社 | Method for producing zinc-chromium composite electroplated steel sheet |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5815554B2 (en) * | 1980-03-24 | 1983-03-26 | 新日本製鐵株式会社 | Plated steel materials for cationic electrodeposition coating |
| JPS60125395A (en) * | 1983-12-09 | 1985-07-04 | Kawasaki Steel Corp | Zn-alumina composite electroplated steel sheet having high corrosion resistance |
| JPS61270398A (en) * | 1985-05-25 | 1986-11-29 | Kawasaki Steel Corp | Composite plated steel sheet having high corrosion resistance and its manufacture |
| JPH0228464B2 (en) * | 1985-08-28 | 1990-06-25 | Nippon Steel Corp | KOTAISHOKUSEIYOSETSUKANOTOSOKOHAN |
-
1987
- 1987-08-06 JP JP62195343A patent/JP2707085B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2562607B2 (en) | 1987-08-06 | 1996-12-11 | 新日本製鐵株式会社 | Method for producing zinc-chromium composite electroplated steel sheet |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6439398A (en) | 1989-02-09 |
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