JPH0466693A - Double layer alloy electroplated steel sheet - Google Patents
Double layer alloy electroplated steel sheetInfo
- Publication number
- JPH0466693A JPH0466693A JP17796490A JP17796490A JPH0466693A JP H0466693 A JPH0466693 A JP H0466693A JP 17796490 A JP17796490 A JP 17796490A JP 17796490 A JP17796490 A JP 17796490A JP H0466693 A JPH0466693 A JP H0466693A
- Authority
- JP
- Japan
- Prior art keywords
- alloy
- layer
- plating
- steel sheet
- content
- 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
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 74
- 239000000956 alloy Substances 0.000 title claims abstract description 74
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 62
- 239000010959 steel Substances 0.000 title claims abstract description 62
- 238000007747 plating Methods 0.000 claims abstract description 73
- 229910007567 Zn-Ni Inorganic materials 0.000 claims abstract description 37
- 229910007614 Zn—Ni Inorganic materials 0.000 claims abstract description 37
- 229910000531 Co alloy Inorganic materials 0.000 claims description 3
- 238000000576 coating method Methods 0.000 abstract description 36
- 239000011248 coating agent Substances 0.000 abstract description 35
- 238000005260 corrosion Methods 0.000 abstract description 32
- 230000007797 corrosion Effects 0.000 abstract description 31
- 238000000034 method Methods 0.000 abstract description 25
- 229910017709 Ni Co Inorganic materials 0.000 abstract description 20
- 229910003267 Ni-Co Inorganic materials 0.000 abstract description 19
- 229910003262 Ni‐Co Inorganic materials 0.000 abstract description 19
- 238000000227 grinding Methods 0.000 abstract description 18
- 238000009713 electroplating Methods 0.000 abstract description 16
- 229910052759 nickel Inorganic materials 0.000 abstract description 7
- 239000002932 luster Substances 0.000 abstract description 5
- 238000010422 painting Methods 0.000 description 11
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 229910000990 Ni alloy Inorganic materials 0.000 description 6
- 239000000243 solution Substances 0.000 description 5
- 239000004575 stone Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 229910003266 NiCo Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- 238000004070 electrodeposition Methods 0.000 description 3
- 229910000765 intermetallic Inorganic materials 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 125000002091 cationic group Chemical group 0.000 description 2
- 239000010960 cold rolled steel Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 239000010452 phosphate Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 229920000298 Cellophane Polymers 0.000 description 1
- MKYBYDHXWVHEJW-UHFFFAOYSA-N N-[1-oxo-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propan-2-yl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(C(C)NC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 MKYBYDHXWVHEJW-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 206010000496 acne Diseases 0.000 description 1
- 239000002390 adhesive tape Substances 0.000 description 1
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 229940044175 cobalt sulfate Drugs 0.000 description 1
- 229910000361 cobalt sulfate Inorganic materials 0.000 description 1
- KTVIXTQDYHMGHF-UHFFFAOYSA-L cobalt(2+) sulfate Chemical compound [Co+2].[O-]S([O-])(=O)=O KTVIXTQDYHMGHF-UHFFFAOYSA-L 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000007772 electroless plating Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010438 granite Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Landscapes
- Electroplating Methods And Accessories (AREA)
Abstract
Description
【発明の詳細な説明】
皮果よ盆机月分立
本発明は、耐食性、めっき層の密着性及び塗装後の耐低
温衝撃剥離性にすぐれる複層合金電気めっき鋼板に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multilayer alloy electroplated steel sheet that has excellent corrosion resistance, adhesion of a plating layer, and low-temperature impact peeling resistance after coating.
従来■狭止
Ｚｎ−Ｎｉ系合金電気めっき鋼板は、そのすぐれた耐食
性のために、自動車用防錆鋼板として広（用いられてい
る。Ｚ ｎ −Ｎ ｉ系合金めっきは、Ｎｉ含有率１０
〜１５％のγ相Ｚ ｎ −Ｎ ｉ合金を主体とするとき
に最高の耐食性を有する。しかし、このγ相は、金属間
化合物であって、Ｚｎ、Ｎｉ等の単一金属や、更には素
地鋼板に比べて、その硬度が高く、脆いために、以下に
述べるような種々の問題がある。Conventional Narrow Zn-Ni alloy electroplated steel sheets are widely used as rust-proof steel sheets for automobiles due to their excellent corrosion resistance.Zn-Ni alloy plating has a Ni content of 10
It has the highest corrosion resistance when it is mainly composed of ~15% γ phase Zn-Ni alloy. However, this γ phase is an intermetallic compound and has higher hardness and brittleness than single metals such as Zn and Ni or even base steel sheets, so it causes various problems as described below. be.
先ず、第１に、プレス加工において、素地鋼が塑性変形
する際に、Ｚｎ−Ｎｉ合金めつき相がこれに追随できず
に、めっき層に割れが生じ、更に、素地鋼の変形が進む
につれて、めっき層が粉末状に剥離する所謂パウダリン
グの現象が起こる。このようなパウダリングが著しくな
ると、発生したパウダーがプレス型に蓄積されて、型の
手入れの頻度が増加するのみならず、蓄積されたパウダ
ーのためにプレス製品にピンプルやプレスブッと呼ばれ
る表面欠陥が生じやすくなる。Firstly, during press working, when the base steel is plastically deformed, the Zn-Ni alloy plating phase cannot follow this and cracks occur in the plating layer, and furthermore, as the base steel deforms further, , a so-called powdering phenomenon occurs in which the plating layer peels off into powder. When this type of powdering becomes significant, the generated powder accumulates in the press mold, which not only increases the frequency of mold maintenance, but also causes surface defects called pimples and press bumps on the pressed product due to the accumulated powder. more likely to occur.
第２に、上述したような加工によるめっき層の割れや剥
離が起こると、めっき鋼板の耐食性が劣化する。Ｚｎ−
Ｎｉ系合金めっき層は、鋼に対して電位的に卑であって
、素地鋼に対して犠牲的防食作用を有するために、めっ
き層の割れや剥離が直ちに耐食性の大幅な低下に繋がる
ものでもないが、やはり加工によるＺｎ−Ｎｉ系合金電
気めっき鋼板の耐食性が低下することは避けられない。Second, when the plating layer cracks or peels off due to the above-described processing, the corrosion resistance of the plated steel sheet deteriorates. Zn-
Since the Ni-based alloy plating layer is potentially less noble than the steel and has a sacrificial anti-corrosion effect on the base steel, cracking or peeling of the plating layer may immediately lead to a significant decrease in corrosion resistance. However, it is still unavoidable that the corrosion resistance of the Zn-Ni alloy electroplated steel sheet decreases due to processing.
第３に、Ｚｎ−Ｎｉ系合金電気めっき鋼板に自動車用３
コート塗装（塗膜厚さ約１００μｍ）を施した後、冬季
の高速道路走行時における路上での石跳ね（チッピング
）を想定して、−２０℃にて飛び石試験を行なうと、石
の衝突した箇所を起点として、塗膜がめつき層と素地鋼
板との界面から大きく剥離することが見出される。この
塗膜の剥離部には、めっき層が残存しておらず、ここか
ら赤錆が短期間に発生する。Thirdly, Zn-Ni alloy electroplated steel sheet is coated with automotive grade 3.
After applying a coating (approximately 100 μm thick), a stone flying test was conducted at -20°C to simulate the chipping caused by stones on the road when driving on a highway in winter. It is found that the coating film largely peels off from the interface between the plating layer and the base steel sheet starting from this point. No plating layer remains in the peeled part of the paint film, and red rust will develop from there in a short period of time.
従って、Ｚｎ−Ｎｉ系合金電気めっき塗装鋼板のチッピ
ングによる上記のような塗膜剥離による耐食性の劣化を
防止するためには、上記塗膜剥離径を小さくして、衝撃
に対する抵抗（以下、この特性を耐低温衝撃剥離性とい
う。）を高めることが必要である。Therefore, in order to prevent deterioration of corrosion resistance due to the above-mentioned coating peeling due to chipping of Zn-Ni alloy electroplated painted steel sheets, it is necessary to reduce the diameter of the coating peeled off and improve the impact resistance (hereinafter, this property). (referred to as low-temperature impact peeling resistance).
尚、Ｚｎ−Ｎｉ系合金電気めっき鋼板を原板とするプレ
コートＥ板を曲げ又は剪断加工したときにも、加工部の
塗膜がめつき層と素地鋼との界面から剥離する現象がみ
られるが、これも低温衝撃剥離と同じ現象であるとみる
ことができる。Furthermore, when bending or shearing a pre-coated E plate made from a Zn-Ni alloy electroplated steel plate as a base plate, there is also a phenomenon in which the coating film in the processed area peels off from the interface between the plating layer and the base steel. This can also be considered to be the same phenomenon as low-temperature impact peeling.
第４に、Ｚｎ−Ｎｉ系合金電気めっき鋼板は、そのすぐ
れた光沢と美麗な外観を利用して、電気製品のシャーシ
ーや内装品等に塗装なしで用いられることがある。この
場合、めっき層の光沢が均一でむらのないことが特に要
求される。しかし、めっき時のめつき液中の鉛等の不純
物や、めっき液中のＺｎイオンとＮｉイオンとの組成比
率によっては、光沢が安定せず、めっき液の流れに沿っ
て光沢むらが生じて、製品価値を著しく低めることがあ
る。Fourth, Zn--Ni alloy electroplated steel sheets are sometimes used without painting for the chassis and interior parts of electrical products, taking advantage of their excellent gloss and beautiful appearance. In this case, it is particularly required that the plating layer has uniform and uniform gloss. However, depending on impurities such as lead in the plating solution during plating or the composition ratio of Zn ions and Ni ions in the plating solution, the gloss may not be stable and uneven gloss may occur along the flow of the plating solution. , may significantly reduce product value.
以上のようなＺｎ−Ｎｉ系合金電気めっき鋼板の有する
問題を解決するために、既に種々の方法が提案されてい
る。例えば、特開昭５６−１６６３８９号公報には、鋼
板上にＮｉ５Ｃｏ又はＣｕの単一金属層を０．０３〜０
．５０μｍの膜厚にて被覆した後、Ｚｎ−Ｎｉ合金電気
めっきを行なう方法が提案されている。しかし、このよ
うに、鋼板に予め単一金属層をプレめっきする方法によ
れば、プレめっき厚の増加につれて、当初は、塗装後の
耐低温衝撃剥離性が向上するが、プレめっき厚がある値
を越えると、プレめっき金属の種類によって定まる一定
の値以上には向上しなくなる。従って、耐低温衝撃剥離
性をそれ以上に向上させるには、単一金属のプレめっき
を施す以外の方法によらざるを得ない。更に、Ｃｕをプ
レめっきした場合には、耐食性の大幅な低下が避けられ
ない。Various methods have already been proposed to solve the problems of Zn-Ni alloy electroplated steel sheets as described above. For example, JP-A-56-166389 discloses that a single metal layer of Ni5Co or Cu is coated on a steel plate with a thickness of 0.03 to 0.
．． A method has been proposed in which Zn--Ni alloy electroplating is performed after coating with a film thickness of 50 μm. However, according to the method of pre-plating a single metal layer on a steel sheet in advance, as the pre-plating thickness increases, the low-temperature impact peeling resistance after painting initially improves; If this value is exceeded, the improvement will no longer exceed a certain value determined by the type of pre-plated metal. Therefore, in order to further improve the low-temperature impact peeling resistance, it is necessary to use a method other than pre-plating with a single metal. Furthermore, when pre-plating with Cu, a significant decrease in corrosion resistance is inevitable.
他方、特開昭５８−６９９５号公報には、ＺｎＮｉ合金
電気めっき層の下層として、Ｎｉ含有率２〜９％のη相
とγ相との混合相からなるＺｎＮｉ合金めつきを厚さ０
．０５〜２μｍにて形成した後、Ｎｉ含有率１０〜２０
％のγ相単相からなるＺｎ−Ｎｉ合金めっきを施す方法
が提案されている。確かに、この方法によれば、塗装後
の耐低温衝撃剥離性をある程度は向上させることができ
るが、しかし、下層が前述のようにη相とγ相との混合
相からなるために、耐食性が劣化するのみならず、この
Ｎｉ含有率２〜９％の下層は光沢をもたないので、単独
では光沢を有するＮｉ含有率１０〜１５％のＴ単相のＺ
ｎ−Ｎｉ合金めっきをその上に施しても、最早、光沢あ
る美麗なめつき表面を得ることができない。On the other hand, JP-A-58-6995 discloses that ZnNi alloy plating consisting of a mixed phase of η phase and γ phase with a Ni content of 2 to 9% is used as the lower layer of the ZnNi alloy electroplating layer to a thickness of 0.
．． After forming with a thickness of 05 to 2 μm, the Ni content is 10 to 20
A method has been proposed in which a Zn-Ni alloy plating consisting of a single γ phase of % is applied. It is true that this method can improve the low-temperature impact peeling resistance after painting to some extent, but since the lower layer is composed of a mixed phase of η phase and γ phase as described above, corrosion resistance Not only does this deteriorate, but the lower layer with a Ni content of 2 to 9% does not have luster.
Even if n-Ni alloy plating is applied thereon, it is no longer possible to obtain a shiny and beautiful plated surface.
また、下層に上層よりもＮｉ含有率の高いＺｎ−Ｎｉ合
金を０．０５〜０．８μｍの厚さに施した後に、所定の
Ｚｎ−Ｎｉ合金電気めっきを施す方法が特開昭５８−２
０１４９６号公報に提案されている。この方法によれば
、本発明者らの実験によれば、下層のＮｉ含有率が２０
％よりも少ないときには、塗装後の耐低温衝撃剥離性の
向上に効果がある。しかし、Ｎｉ含有率が２０％以上の
場合には、Ｚｎ−Ｎｉ合金電気めっきは、電流効率が低
く、めっき液の組成変動に対して、めっき層の組成が大
きく変動する等、工程管理が困難である。In addition, a method of applying a Zn-Ni alloy having a higher Ni content than the upper layer to a thickness of 0.05 to 0.8 μm on the lower layer and then electroplating the Zn-Ni alloy is disclosed in JP-A-58-2.
This is proposed in the No. 01496 publication. According to this method, according to experiments by the present inventors, the Ni content in the lower layer is 20
%, it is effective in improving low-temperature impact peeling resistance after coating. However, when the Ni content is 20% or more, Zn-Ni alloy electroplating has low current efficiency, and the composition of the plating layer changes greatly in response to changes in the composition of the plating solution, making process control difficult. It is.
更に、先ず、Ｚｎ−Ｎｉ合金めっきを極く薄くめつきし
、そのめっき層をめっき液にて一部再溶解した後、所定
のめつき厚のＺ ｎ −Ｎ ｉ合金めつきを施す方法が
特開昭６２−２１）３９７号公報に記載されている。こ
の方法は、最初の極薄Ｚｎ−Ｎｉめつき厚及びその後の
再溶解時間を適切に選択すれば、塗装後の耐低温衝撃剥
離性や耐パウダリング性の改善に有効である。しかし、
この方法に要求される再溶解時間を既設の水平型電気亜
鉛めっきラインで確保しようとすれば、−乃至複数のめ
つきセルを無通電の状態に置かねばならず、生産性の低
下を免れない。また、この方法による製品の表面光沢は
、通常のＺｎ−Ｎｉ合金めっきに比べて、光沢むらを生
じやすい欠点がある。Furthermore, there is a method in which first a very thin Zn-Ni alloy plating is applied, a part of the plating layer is redissolved in a plating solution, and then Zn-Ni alloy plating is applied to a predetermined plating thickness. It is described in Japanese Unexamined Patent Publication No. 62-21) 397. This method is effective in improving the low-temperature impact peeling resistance and powdering resistance after coating, if the initial extremely thin Zn-Ni plating thickness and the subsequent remelting time are appropriately selected. but,
If the remelting time required for this method is to be achieved using an existing horizontal electrogalvanizing line, one or more plating cells must be left de-energized, which inevitably reduces productivity. . Furthermore, the surface gloss of products produced by this method has the disadvantage that it is more likely to produce uneven gloss than ordinary Zn-Ni alloy plating.
上記した以外にも、鋼板のめつき前処理を強化する方法
が提案されている。例えば、鋼板を電解酸洗する方法が
特開昭６３−２３８２９７号公報に記載されており、ま
た、めっき前に鋼板の表面を砥粒入り研磨剤で研磨する
方法が特開昭６３−１４００９８号公報に記載されてい
る。しかし、これらの方法は、耐パウダリング性や塗装
後の耐低温衝撃剥離性を改善する補助手段にすぎず、こ
れらめっきの前処理強化のみによっては、到底、塗装後
の耐低温衝撃剥離性を自動車鋼板に要求される厳しいレ
ベルに到達させることはできない。In addition to the methods described above, methods for strengthening the plating pretreatment of steel sheets have been proposed. For example, a method of electrolytically pickling a steel plate is described in JP-A-63-238297, and a method of polishing the surface of a steel plate with an abrasive containing abrasive before plating is described in JP-A-63-140098. It is stated in the official gazette. However, these methods are only auxiliary means for improving powdering resistance and low-temperature impact peeling resistance after painting, and it is impossible to improve the low-temperature impact peeling resistance after painting by simply strengthening the pre-treatment of plating. It is not possible to reach the strict level required for automobile steel sheets.
明が解決しようとする課
以上のように、従来、種々の方法が提案されているもの
の、これらによっては、前述したＺｎ−Ｎｉ系合金電気
めっき鋼板における問題を同時に解決することができず
、新たな技術が強く要望されている。As mentioned above, although various methods have been proposed in the past, these methods have not been able to simultaneously solve the above-mentioned problems with Zn-Ni alloy electroplated steel sheets, and new methods have been proposed. There is a strong demand for such technology.
本発明は、かかる要望に応えるためになされたものであ
って、塗装後の耐低温衝撃剥離性、耐パウダリング性、
耐食性及び表面光沢のすべてにすぐれる複層合金電気め
っき鋼板を提供することを目的とする。The present invention was made in response to such demands, and includes low-temperature impact peeling resistance, powdering resistance, and
The purpose of the present invention is to provide a multilayer alloy electroplated steel sheet that has excellent corrosion resistance and surface gloss.
１ を”′するための
本発明による複層合金電気めっき鋼板は、銅板上に第１
層としてＣｏ含有率５〜２０％のＮｉＣｏ系合金めっき
層を付着量０．０５〜１．０ｇ／ｍにて有し、第２層と
してＮｉ含有率８〜１６％のＺｎ−Ｎｉ系合金電気めっ
きを有することを特徴とする。The multi-layer alloy electroplated steel sheet according to the present invention for coating
The layer has a NiCo alloy plating layer with a Co content of 5 to 20% at a coating weight of 0.05 to 1.0 g/m, and the second layer has a Zn-Ni alloy plating layer with a Ni content of 8 to 16%. It is characterized by having plating.
本発明による複層合金電気めっき鋼板は、針板上に第１
層としてＣｏ含有率５〜２０％のＮｉＣｏ系合金めっき
層を付着量０．０５〜１．０ ｇ／ｍにて有する。Ｎｉ
−Ｃｏ系合金めっきは、Ｃｏ含有率が５〜２０％の範囲
にあるときに、耐パウダリング性、塗装後の耐低温衝撃
剥離性及び耐食性において、Ｎｉ又はＣｏの単一金属層
よりもすぐれる。第１図に、下層のＮｉ−Ｃｏ系合金め
っきにおけるＣＯ含を率とめつき層の耐パウダリング性
との、関係を示す。また、第２図に、下層のＮｉ−Ｃｏ
系合金めっきにおけるＣｏ含有率と塗装後の耐低温衝撃
剥離性との関係を示す。The multi-layer alloy electroplated steel sheet according to the present invention has a first
As a layer, it has a NiCo alloy plating layer with a Co content of 5 to 20% at a coating weight of 0.05 to 1.0 g/m. Ni
-Co-based alloy plating has better powdering resistance, low-temperature impact peeling resistance after coating, and corrosion resistance than single metal layers of Ni or Co when the Co content is in the range of 5 to 20%. It will be done. FIG. 1 shows the relationship between the CO content in the lower Ni--Co alloy plating and the powdering resistance of the plating layer. In addition, Fig. 2 shows the lower layer of Ni-Co.
The relationship between Co content in alloy plating and low-temperature impact peeling resistance after coating is shown.
上記のように、Ｃｏ含有率が５〜２０％の範囲にあると
きに、Ｎｉ−Ｃｏ系合金めっきが耐パウダリング性、塗
装後の耐低温衝撃剥離性及び耐食性において、Ｎｉ又は
Ｃｏの単一金属層よりもすぐれる理由は、必ずしも明ら
かではないが、以下のようであるみられる。As mentioned above, when the Co content is in the range of 5 to 20%, the Ni-Co alloy plating has excellent powdering resistance, low-temperature impact peeling resistance after coating, and corrosion resistance. The reason why it is better than a metal layer is not necessarily clear, but it appears to be as follows.
パウダリングと低温衝撃剥離性は、共にめっき層がＺｎ
−Ｎｉ合金層と素地鋼板との界面にて剥離するところか
ら、それらが生じるのは、ＺｎＮｉ合金層と目地鋼板と
の間の密着性に問題があるとみられる。Powdering and low-temperature impact peelability are both achieved when the plating layer is Zn.
Since peeling occurred at the interface between the -Ni alloy layer and the base steel plate, it seems that the reason for this is that there is a problem in the adhesion between the ZnNi alloy layer and the joint steel plate.
Ｎｉ又はＣＯをプレめっきすることによって、Ｚｎ−Ｎ
ｉ合金層と素地鋼板との間の密着性が向上する。その理
由は、ＮｉやＣｏがＺｎ−Ｎｉ合金のような金属間化合
物ではないために、延性に冨み、その結果、力がめつき
層と素地との間を伝わる際に一種の緩和層となること、
また、ＮｉやＣｏが素地鋼板とＺｎ−Ｎｉ合金との原子
間隔のミスフィツトを小さくする方向に働いて、素地鋼
とプレめっきとの密着力及びプレめっきとＺｎＮｉ合金
との密着力が共に素地鋼板とＺｎ−Ｎｉ合金との密着力
に比べて大きくなるためであるとみられる。By pre-plating with Ni or CO, Zn-N
The adhesion between the i-alloy layer and the base steel plate is improved. The reason is that Ni and Co are not intermetallic compounds like Zn-Ni alloys, so they are highly ductile, and as a result, they act as a kind of relaxation layer when force is transmitted between the plating layer and the base material. thing,
In addition, Ni and Co work to reduce the atomic spacing misfit between the base steel sheet and the Zn-Ni alloy, so that the adhesion between the base steel and the pre-plating and the adhesion between the pre-plating and the ZnNi alloy are both improved. This seems to be because the adhesion force between the Zn-Ni alloy and the Zn-Ni alloy becomes larger than that of the Zn-Ni alloy.
本発明に従って、プレめっきをＣｏ含有率５〜２０％の
Ｎｉ−Ｃｏ合金とすることによって、耐パウダリング性
及び耐低温衝撃剥離性がＮｉ又はＣＯの単独金属の場合
よりも更に向上する理由は、この範囲のＮｉ−Ｃｏ合金
がＮｉ中に固溶した固溶体の状態にあって、脆い金属間
化合物ではないこと、及び前述したように、原子間隔の
ミスフィットが上記範囲のＮ ｉ −Ｃｏ合金によって
最適化できること、更に、プレめっき層の電着応力が上
記範囲で最小となること等の効果が総合的に働く結果に
よるものとみられる。The reason why the powdering resistance and low-temperature impact peeling resistance are further improved by using a Ni-Co alloy with a Co content of 5 to 20% as the pre-plating according to the present invention, compared to the case of Ni or CO alone. , the Ni-Co alloy in this range is in the state of a solid solution in Ni and is not a brittle intermetallic compound, and as mentioned above, the Ni-Co alloy with the atomic spacing misfit in the above range This seems to be due to the comprehensive effects of being able to optimize the process by optimizing the process and minimizing the electrodeposition stress of the pre-plated layer within the above range.
次に、下層Ｎｉ−Ｃｏ合金のＣＯ含有率と耐食性との関
係を第３図に示すように、ＣＯ含有率が５〜２０％の範
囲にあるときに、耐食性の向上がみられる。その理由は
、Ｎｉ−Ｃｏ合金の均一被覆性がよいために、腐食によ
って、Ｚｎ−Ｎｉめつき層に割れが生じた場合にも、Ｎ
ｉ −（、ｏプレめっき層の欠陥が少ないために、素
地鋼板の露出が少ないことにあるとみられる。Next, as shown in FIG. 3, which shows the relationship between the CO content of the lower Ni-Co alloy and the corrosion resistance, the corrosion resistance is improved when the CO content is in the range of 5 to 20%. The reason for this is that the Ni-Co alloy has good uniform coverage, so even if cracks occur in the Zn-Ni plated layer due to corrosion, the N
i - (, o This seems to be because there are few defects in the pre-plated layer, so the base steel sheet is less exposed.
更に、本発明においては、下層のＮｉ−Ｃｏ合金めつき
の素地鋼板への付着量は、０．０５〜１．０ｇ／ｒｒｒ
の範囲にあることが必要である。第４図に、下層のＮｉ
−Ｃｏ合金めつきの付着量と塗装後の耐低温衝撃剥離性
との関係を第４図に示す。下層の付着量が０．０２ｇ／
％以上において、塗膜剥離径の低下がみられ、特に、０
．２ ｇ ／ ｇ以上において、塗膜剥離径がほぼ一定
になることが示されている。Furthermore, in the present invention, the adhesion amount of the lower layer Ni-Co alloy plating to the base steel plate is 0.05 to 1.0 g/rrr.
It is necessary to be within the range of . Figure 4 shows the lower layer of Ni.
FIG. 4 shows the relationship between the amount of -Co alloy plating and the low-temperature impact peeling resistance after coating. Lower layer adhesion amount is 0.02g/
% or more, a decrease in the peeling diameter of the coating film was observed, especially at 0.
．． It has been shown that at 2 g/g or more, the peeled diameter of the coating film becomes almost constant.
また、耐食性に関しては、下層の付着量が０．０５ ｇ
／ｒｄであるとき、赤錆の発生時間の延長が認められ、
０．１ｇ／ｍ以上で一定となる。In addition, regarding corrosion resistance, the coating amount of the lower layer is 0.05 g.
/rd, the development time of red rust was observed to be extended,
It becomes constant at 0.1 g/m or more.
本発明において、上述したようなＮｉ−Ｃｏプレめっき
は、電気めっき法のほか、無電解めっき法、置換めっき
法、蒸着めっき法等、いずれの方法によって、鋼板上に
めっきされていてもよい。In the present invention, the Ni-Co pre-plating as described above may be plated on the steel plate by any method such as electroless plating, displacement plating, vapor deposition plating, etc. in addition to electroplating.
本発明による複層合金電気めっき鋼板においては、かか
る下層の上に、第２層としてＮｉ含有率８〜１６％のＺ
ｎ−Ｎｉ合金電気めっきを有する。In the multilayer alloy electroplated steel sheet according to the present invention, a second layer of Z with a Ni content of 8 to 16% is formed on the lower layer.
Has n-Ni alloy electroplating.
このＺｎ−Ｎｉ合金電気めっきにおいて、Ｎｉ含有率が
８％よりも少ないときは、Ｚｎ−Ｎｉ合金電気めっき鋼
板の塗装後の耐低温衝撃剥離性や耐パウダリング性が、
耐食性が最良であるＮｉ含有率１３％のＺｎ−Ｎｉ合金
めつきに比べてすぐれているので、Ｎｉ−Ｃｏプレめっ
きによる改良の必要がないのみならず、耐食性がＮｉ−
Ｃｏプレめっきを施しても向上せず、また、表面光沢も
Ｎｉ−Ｃｏプレめっきを施しても向上しないからである
。他方、Ｎｉ含有率が１６％を越えるときは、耐食性が
致命的に劣化する。In this Zn-Ni alloy electroplating, when the Ni content is less than 8%, the low-temperature impact peeling resistance and powdering resistance after coating of the Zn-Ni alloy electroplated steel sheet are
Since the corrosion resistance is superior to that of Zn-Ni alloy plating with a Ni content of 13%, which has the best Ni content, not only is there no need for improvement by Ni-Co pre-plating, but the corrosion resistance is also superior to that of Ni-Co pre-plating.
This is because the Co pre-plating does not improve the surface gloss, and the Ni--Co pre-plating does not improve the surface gloss. On the other hand, when the Ni content exceeds 16%, corrosion resistance is fatally deteriorated.
このようなＺｎ−Ｎｉ合金電気めっきの付着量は、鋼板
の用いられる環境によって適宜に選択されるが、通常、
１０〜５０ ｇ／ｍの範囲である。The amount of Zn-Ni alloy electroplating is appropriately selected depending on the environment in which the steel sheet is used, but usually
It ranges from 10 to 50 g/m.
大施炎
以下に実施例を挙げて本発明を説明するが、本発明はこ
れら実施例により何ら限定されるものではない。EXAMPLES The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples in any way.
厚さ０．８鶴の冷延鋼板を電解脱脂し、酸洗後、電気め
っき法にてＮ ｉ −Ｃｏプレめっきを施した。A cold-rolled steel sheet with a thickness of 0.8 mm was electrolytically degreased, pickled, and then pre-plated with Ni-Co using an electroplating method.
めっき浴としては硫酸塩浴を用い、付着量は単位面積当
りの通電量で調整し、また、ＣＯ含有率は浴中の硫酸コ
バルト濃度で調整した。A sulfate bath was used as the plating bath, the amount of adhesion was adjusted by the amount of current applied per unit area, and the CO content was adjusted by the concentration of cobalt sulfate in the bath.
このＮｉ−Ｃｏプレめっきの後、更に、鋼板にＺｎ−Ｎ
ｉ合金電気めっきを施し、水洗、乾燥した。Ｚｎ−Ｎｉ
合金電気めっきの付着量は、単位面積当りの通電量によ
って調整し、また、Ｎｉ含有率は浴中のＮｉイオンとＺ
ｎイオンとの比率によって調整した。After this Ni-Co pre-plating, Zn-N is further applied to the steel plate.
It was subjected to i-alloy electroplating, washed with water, and dried. Zn-Ni
The amount of alloy electroplating is adjusted by the amount of current applied per unit area, and the Ni content is determined by adjusting the Ni ions and Z in the bath.
It was adjusted by the ratio with n ions.
このようにして得られた複層合金電気めっき鋼板の組成
を第１表に示す。The composition of the multilayer alloy electroplated steel sheet thus obtained is shown in Table 1.
鋼板の耐パウダリング性、塗装後の耐低温衝撃剥離性、
耐食性及び表面光沢は、以下のようにして評価した。Powdering resistance of steel plates, resistance to low-temperature impact peeling after painting,
Corrosion resistance and surface gloss were evaluated as follows.
菫バ文久ユｌ久血
めっき鋼板をＪＩＳ Ｓ号引張試験片に加工し、引張試
験機を用いて、ゲージ長５０ｍにて３０％の伸びを与え
た後、加工部をセロハン粘着テープにてテーピングし、
これを剥離して、テープに付着した粉末状のめっき片を
塩酸に溶解して、原子吸光分析にて定量した。Process the Sumaba Bunkyu Yul Kublood plated steel plate into a JIS No. S tensile test piece, use a tensile tester to give it 30% elongation at a gauge length of 50 m, and then tape the processed part with cellophane adhesive tape. death,
This was peeled off, and the powdered plating pieces adhering to the tape were dissolved in hydrochloric acid and quantified by atomic absorption spectrometry.
楡壮′の低ゞ衝俵
めっき鋼板を自動車用塗装工程に従って、浸漬法リン酸
塩処理、カチオン電着塗装（２０μｍ）、中塗り（４０
μｍ）、上塗り （４０μｍ）をそれぞれ施した後、−
２０℃の冷凍機中に２４時間保管し、取り出した直後に
グラベロメーターにて以下の条件にて塗膜にチッピング
を行なった。Yusou's low-impact bale-plated steel sheets are subjected to dipping phosphate treatment, cationic electrodeposition coating (20μm), and intermediate coating (40μm) according to the automotive coating process.
μm) and a topcoat (40 μm), respectively, -
It was stored in a refrigerator at 20° C. for 24 hours, and immediately after being taken out, the coating film was chipped using a gravelometer under the following conditions.
石の種類： 花崗岩
石の径ニア、９〜１）．１ｍｍ
石の量： １００ｇ／回
空気厚： ４．Ｏｋｇｆ／ｃｍ２
チッピング後の鋼板は、テーピングをはずした後、剥離
した塗膜径を測定した。測定は、剥離径が最大のものに
ついて行ない、ｎ＝５の鋼板の平均値を塗膜剥離径とし
た。Stone type: Granite stone diameter 9-1). 1mm Amount of stones: 100g/time Air thickness: 4. Okgf/cm2 After removing the taping from the chipped steel plate, the diameter of the peeled coating film was measured. The measurement was performed on the one with the largest peeling diameter, and the average value of n=5 steel plates was taken as the coating film peeling diameter.
１皇牲
塗装を施さない状態での所謂裸耐食性と塗装後の耐食性
の双方を評価した。1. Both the so-called bare corrosion resistance without any coating and the corrosion resistance after coating were evaluated.
裸耐食性は、めっき鋼板にＪＩＳ Ｚ ２３７１に規定
する塩水噴霧試験を行ない、赤錆が試験片片面に１％光
発生るまでの時間によって評価した。Bare corrosion resistance was evaluated by subjecting a plated steel plate to a salt spray test specified in JIS Z 2371, and determining the time required for 1% red rust to appear on one side of the test piece.
塗装後の耐食性は、めっき鋼板を浸漬法リン酸塩処理及
びカチオン電着塗装（２０μｍ）を行なった後、塗膜に
クロスカットを施し、塩水噴霧試験を８４０時間行なっ
た後、塗膜のクロスカットからの膨れ幅にて評価した。Corrosion resistance after coating was determined by subjecting a plated steel plate to dipping phosphate treatment and cationic electrodeposition coating (20 μm), cross-cutting the coating, and conducting a salt spray test for 840 hours. Evaluation was made based on the width of the bulge from the cut.
ｌ凱光沢
めっき鋼板の表面光沢を目視にて次の４段階にて評価し
た。The surface gloss of the brightly plated steel sheet was visually evaluated on the following four scales.
均一な光沢がある： ◎僅かに光沢に
むらがある： ○光沢にむらがある：
△光沢のむらが著しいか、光沢がない：
×以上の結果を第１表に示す。実施例１〜４と比較例１
〜４とを比べれば明らかなように、ＮｉＣｏプレめっき
のＣＯ含有率が５〜２０％の範囲で、本発明による複層
電気めっき鋼板が耐パウダリング性、塗装後の耐低温衝
撃剥離性、裸耐食性、塗装後の耐食性にすぐれているこ
とが理解される。Uniform luster: ◎ Slightly uneven luster: ○ Uneven luster:
△ Significantly uneven gloss or no gloss:
The results of × and above are shown in Table 1. Examples 1 to 4 and Comparative Example 1
4, it is clear that when the CO content of NiCo pre-plating is in the range of 5 to 20%, the multilayer electroplated steel sheet according to the present invention has good powdering resistance, low-temperature impact peeling resistance after painting, It is understood that it has excellent corrosion resistance both in bare corrosion and after painting.
また、実施例５〜８と比較例５〜７とを比べれば明らか
なように、Ｎｉ Ｃｏプレめっきの付着量が０．０５
ｇ／ｒｒｉ以上であるとき、本発明による複層合金めっ
き鋼板が耐パウダリング性、塗装後の耐低温衝撃剥離性
、裸耐食性及び塗装後の耐食性、表面光沢にすぐれてい
ることが示されている。Moreover, as is clear from comparing Examples 5 to 8 and Comparative Examples 5 to 7, the amount of Ni Co pre-plating was 0.05.
g/rri or more, it has been shown that the multilayer alloy coated steel sheet according to the present invention has excellent powdering resistance, low-temperature impact peeling resistance after painting, bare corrosion resistance, corrosion resistance after painting, and surface gloss. There is.
更に、実施例９及び１０と比較例８及び９とを比較すれ
ば明らかなように、耐食性、表面光沢共にすくれたＺｎ
−Ｎｉ合金電気めっきのＮｉ含有率は８〜１６％の範囲
であることが理解される。Furthermore, as is clear from the comparison between Examples 9 and 10 and Comparative Examples 8 and 9, Zn has poor corrosion resistance and surface gloss.
It is understood that the Ni content of the -Ni alloy electroplating ranges from 8 to 16%.
発所■菱果
以上のように、本発明による複層合金電気めっき鋼板は
、従来のＺｎ−Ｎｉ合金電気めっき網板における問題で
あった耐パウダリング性と塗装後の耐低温衝撃剥離性が
改善されているのみならず、Ｚｎ−Ｎｉ合金電気めっき
鋼板の特徴である高耐食性と表面光沢とが一層改善され
ている。Source: Diamond As mentioned above, the multilayer alloy electroplated steel sheet according to the present invention has improved powdering resistance and low-temperature impact peeling resistance after painting, which were problems with conventional Zn-Ni alloy electroplated mesh sheets. Not only has this been improved, but the high corrosion resistance and surface gloss, which are characteristics of Zn-Ni alloy electroplated steel sheets, have been further improved.
第１図は、冷延鋼板に下層としてＮｉ−Ｃｏ合金めつき
を有し、上層にＺｎ−Ｎｉ （１３％）合金電気めっ
き（付着量３０ｇ／ｍ）を有する複層めっき鋼板におい
て、下層のＮｉ−Ｃｏ合金めつき（付着量０．３ｇ／ｍ
）におけるＣｏ含有率とパウダリング発生量との関係を
示すグラフ、第２図は、下層のＮ ｉ −Ｃｏ合金めつ
きにおけるＣｏ含有率と塗膜剥離径との関係を示すグラ
フ、第３図は、下層Ｎｉ−Ｃｏ合金のＣｏ含有率と塩水
噴霧試験において赤錆１％全発生間との関係を示すグラ
フ、第４図は、冷延鋼板に下層としてのＮ１Ｃｏ（１０
％）合金めっきを有し、上層にＺｎＮｉ （１３％）
合金電気めっき（付着量３０ｇ／ｌ）を有する複層めっ
き鋼板において、下層Ｎｉ−Ｃｏ合金めつきの付着量と
塗膜剥離径との関係を示すグラフである。
第１
図
沈ｕｉ−Ｃｏ伊むＣ６／ざ合本部う
第
図
下／％ Ｍ−Ｃｏ？公”７ Ｃｏ Ｚｉ Ｊ” （ｉ
）第２
図
五層Ｎｉ −Ｃｏ φｔｔＱ Ｃｏ宮翁卆（＝／、）第
ゲ
図
下層Figure 1 shows a cold-rolled steel sheet with Ni-Co alloy plating as the lower layer and Zn-Ni (13%) alloy electroplating (coating amount 30 g/m) on the upper layer. Ni-Co alloy plating (deposition amount 0.3g/m
Figure 2 is a graph showing the relationship between the Co content and the amount of powdering generated in ). is a graph showing the relationship between the Co content of the lower layer Ni-Co alloy and the total occurrence of 1% red rust in the salt spray test.
%) Alloy plating with ZnNi (13%) on top layer
It is a graph showing the relationship between the deposition amount of the lower layer Ni-Co alloy plating and the coating peeling diameter in a multilayer plated steel sheet having alloy electroplating (deposition amount 30 g/l). Figure 1 Shen ui-Co Imu C6/Zagori Honbu Figure bottom/% M-Co? Public “7 Co Zi J” (i
) 2nd figure 5th layer Ni -Co φttQ Co 宮翁卆 (=/,) 5th layer lower layer
Claims (1)
ｉ−Ｃｏ系合金めつき層を付着量０．０５〜１．０ｇ／
ｍ＾２にて有し、第２層としてＮｉ含有率８〜１６％の
Ｚｎ−Ｎｉ系合金電気めつきを有することを特徴とする
複層合金電気めつき鋼板。(1) N with a Co content of 5 to 20% as the first layer on a steel plate
The amount of i-Co alloy plating layer is 0.05~1.0g/
A multi-layer alloy electroplated steel sheet having a Zn-Ni alloy electroplated with a Ni content of 8 to 16% as a second layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2177964A JPH0774472B2 (en) | 1990-07-04 | 1990-07-04 | Multi-layer alloy electric plated steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2177964A JPH0774472B2 (en) | 1990-07-04 | 1990-07-04 | Multi-layer alloy electric plated steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0466693A true JPH0466693A (en) | 1992-03-03 |
| JPH0774472B2 JPH0774472B2 (en) | 1995-08-09 |
Family
ID=16040157
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2177964A Expired - Fee Related JPH0774472B2 (en) | 1990-07-04 | 1990-07-04 | Multi-layer alloy electric plated steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0774472B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008266685A (en) * | 2007-04-17 | 2008-11-06 | Nippon Steel Corp | Method for producing high-tensile strength hot dip galvannealed steel sheet having excellent appearance |
-
1990
- 1990-07-04 JP JP2177964A patent/JPH0774472B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008266685A (en) * | 2007-04-17 | 2008-11-06 | Nippon Steel Corp | Method for producing high-tensile strength hot dip galvannealed steel sheet having excellent appearance |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0774472B2 (en) | 1995-08-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |