JP3230445B2 - Chrome plating method - Google Patents
Chrome plating methodInfo
- Publication number
- JP3230445B2 JP3230445B2 JP32675196A JP32675196A JP3230445B2 JP 3230445 B2 JP3230445 B2 JP 3230445B2 JP 32675196 A JP32675196 A JP 32675196A JP 32675196 A JP32675196 A JP 32675196A JP 3230445 B2 JP3230445 B2 JP 3230445B2
- Authority
- JP
- Japan
- Prior art keywords
- chromium plating
- solution
- amount
- metal impurities
- plating solution
- 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 - Fee Related
Links
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- Electroplating And Plating Baths Therefor (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、クロムめっき方法
に関するものである。[0001] The present invention relates to a chromium plating method.
【０００２】[0002]
【従来の技術】近年、クロムめっき加工技術の発展が遂
げられ、硬質クロムが耐摩耗性に優れるという利点を活
用すべく、使用環境が非常に厳しい鉄鋼の冷間圧延用作
業ロール（以下、「ワークロール」という）にクロムめ
っき加工が施されている。ところで、クロムめっきを施
す場合、操業時間の経過に伴って、クロムめっき液中に
鉄、ニッケル、銅、亜鉛、アルミニウム等の金属不純物
の溶け込み量が増加してくる。2. Description of the Related Art In recent years, chromium plating technology has been developed, and in order to take advantage of the superior wear resistance of hard chromium, working rolls for cold rolling steel (hereinafter referred to as "rolling steel"), which are extremely harsh in use environment. Work rolls) are chrome-plated. By the way, in the case of performing chromium plating, the amount of metal impurities such as iron, nickel, copper, zinc, and aluminum dissolved in the chromium plating solution increases as the operation time elapses.
【０００３】これら金属不純物の溶け込み量の増加に伴
って、図２に示すように、クロムめっき液中の電流効率
が低下してくる。そして、クロムめっき液中の電流効率
が低下すると、所望のめっき膜厚を得るための加工時
間が長くなる、クラック密度が低下してめっき層の硬
さが小さくなる、等作業能率が低下したり、品質不良を
招くという問題があった。As shown in FIG. 2, the current efficiency in the chromium plating solution decreases with an increase in the amount of these metal impurities dissolved. When the current efficiency in the chromium plating solution decreases, the processing time for obtaining a desired plating film thickness increases, the crack density decreases, the hardness of the plating layer decreases, and the work efficiency decreases. However, there is a problem of inferior quality.
【０００４】クロムめっきにおいて、クラック密度が低
下するとめっき層の硬さが小さくなる（密着強度が弱く
なる）のは、以下の理由による。クロムめっきは、めっ
き付着により密着応力（１０〜１３kg/mm2）が働くが、
クロムの伸びは０〜０．１２％である。そこで、めっき
層がある厚さに達すると、密着応力よりも引張応力の方
が強くなるので、めっき層に割れ（クラック）が発生す
る。そして、付着量が多くなると、前記したようにして
クラックが生成され、クロムめっき層が形成される。従
って、密着応力が非常に大きいと、微細なクラックが多
く形成され、反対に密着応力が小さいと、大きなクラッ
クが僅かに生成されることになるからである。[0004] In chromium plating, the lower the crack density, the lower the hardness of the plating layer (the lower the adhesion strength), for the following reasons. In chrome plating, the adhesion stress (10 to 13 kg / mm 2 ) acts due to plating adhesion.
The elongation of chromium is between 0 and 0.12%. Then, when the plating layer reaches a certain thickness, the tensile stress becomes stronger than the adhesion stress, so that the plating layer cracks. When the amount of adhesion increases, cracks are generated as described above, and a chromium plating layer is formed. Therefore, if the adhesion stress is extremely large, many fine cracks are formed, and if the adhesion stress is small, large cracks are slightly generated.
【０００５】そこで、クロムめっきを施す際には、一般
的にクロムめっき液中に含まれる金属不純物（特に鉄
分）の混入量の上限値を設定し、クロムめっき液の管理
を行っている〔白井十四雄，めっき技術便覧，（昭和４
６年），ｐ２１８〜２１９，日刊工業新聞社〕。Therefore, when performing chromium plating, generally, the upper limit of the amount of metal impurities (particularly iron) contained in the chromium plating solution is set, and the chromium plating solution is controlled [Shirai. Shizuo, Handbook of plating technology, (Showa 4
6 years), pp. 218-219, Nikkan Kogyo Shimbun].
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、クロム
めっき液を新液に入れ替えた直後の場合のように、クロ
ムめっき液中の金属不純物が極端に少ない場合や、全く
混入していない場合には、電流効率は高くなるものの、
図２に示すように、クラック密度が低下してめっき層の
硬さが小さくなるので、クロムめっき本来の性能を十分
に満足できなくなり、めっき剥離等の品質不良を招く危
険性があることを本発明者らは見出した。However, when the metal impurities in the chromium plating solution are extremely small, such as immediately after replacing the chromium plating solution with a new solution, or when the chromium plating solution is not mixed at all, Although the current efficiency is higher,
As shown in FIG. 2, the crack density is reduced and the hardness of the plating layer is reduced, so that the original performance of chromium plating cannot be sufficiently satisfied, and there is a risk of causing poor quality such as plating peeling. The inventors have found.
【０００７】従って、前記したようなクロムめっき液中
の金属不純物が極端に少ない場合や全く混入していない
クロムめっき液を用いてワークロールにクロムめっき加
工を行うと、圧延作業中にしばしばめっき層の剥離が発
生する。そして、このようなワークロールで圧延を継続
すると、剥離模様が鋼板の表面に転写されるので、通常
は、このような場合には、ワークロール替えを行い、不
良品の発生を防止している。Therefore, when the work roll is subjected to chromium plating using a chromium plating solution in which the metal impurities in the chromium plating solution are extremely small or a chromium plating solution which is not mixed at all, the plating layer is often formed during the rolling operation. Peeling occurs. Then, when rolling is continued with such a work roll, the peeling pattern is transferred to the surface of the steel sheet. Therefore, in such a case, the work roll is usually changed to prevent the occurrence of defective products. .
【０００８】本発明は、上記した従来の問題点に鑑みて
なされたものであり、クロムめっき液を最良の状態に維
持しつつクロムめっきを行う方法を提供することを目的
としている。The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a method for performing chromium plating while maintaining a chromium plating solution in the best condition.
【０００９】[0009]
【課題を解決するための手段】上記した目的を達成する
ために、本発明のクロムめっき方法は、液替え時、クロ
ムめっき液として、クロムめっき液の一部を入れ替える
ことにより、金属不純物の溶け込み量が０．１〜１５ｇ
／リットルに調整したものを使用することとしている。
そして、このようにすることで、金属不純物がほとんど
含まれておらず、液のなじみの悪い新しいクロムめっき
液を用いてクロムめっきを行った時のようなめっき層の
剥離を防止できる。In order to achieve the above object, the chromium plating method of the present invention replaces a part of the chromium plating solution as the chromium plating solution when changing the solution.
As a result, the amount of dissolved metal impurities is 0.1 to 15 g.
Per liter.
By doing so, it is possible to prevent the plating layer from being peeled off as in the case where chromium plating is performed using a new chromium plating solution that contains almost no metal impurities and has poor compatibility with the solution.
【００１０】[0010]
【発明の実施の形態】本発明のクロムめっき方法は、液
替え時、クロムめっき液の一部を入れ替えることによ
り、金属不純物の溶け込み量が０．１〜１５ｇ／リット
ルに調整したクロムめっき液を使用することとしている
のである。BEST MODE FOR CARRYING OUT THE INVENTION The chromium plating method of the present invention is such that a part of the chromium plating solution is replaced when the solution is changed.
Ri is the penetration amount of metal impurities is decided to use a chromium plating solution was adjusted to 0.1 to 15 g / liter.
【００１１】本発明のクロムめっき方法において、使用
するクロムめっき液における金属不純物の溶け込み量は
０．１〜１５ｇ／リットル、好ましくは１．０〜１２．
０ｇ／リットルである。その理由は、０．１ｇ／リット
ル未満であれば、液のなじみが悪く、圧延作業中にしば
しばめっき層の剥離が発生するからである。また、１５
ｇ／リットルを超えると、クロムめっき液中の電流効率
の低下により、所望のめっき膜厚を得るための加工時間
が長くなったり、また、クラック密度の低下によりめっ
き層の硬さが小さくなり、所期の目的を達成できなくな
るからである。In the chromium plating method of the present invention, the amount of metal impurities dissolved in the chromium plating solution to be used is 0.1 to 15 g / liter, preferably 1.0 to 12 g / l.
0 g / liter. The reason for this is that if it is less than 0.1 g / liter, the solution does not fit well and the plating layer often peels off during the rolling operation. Also, 15
If the amount exceeds g / liter, the current efficiency in the chromium plating solution decreases, and the processing time for obtaining a desired plating film thickness increases, and the hardness of the plating layer decreases due to the decrease in crack density. This is because the intended purpose cannot be achieved.
【００１２】本発明のクロムめっき方法は、クロムめっ
き液に溶け込んだ金属不純物量の下限値をも規定したの
で、クロムめっきの品質として不安定な領域での加工を
回避でき、常に安定した品質の製品を得ることができ
る。In the chromium plating method of the present invention, since the lower limit of the amount of metal impurities dissolved in the chromium plating solution is also specified, processing in an unstable region as chromium plating quality can be avoided, and the chromium plating always has a stable quality. Products can be obtained.
【００１３】[0013]
【実施例】以下、本発明のクロムめっき方法の実施例に
ついて説明する。金属不純物の溶け込み量を１．０〜１
２．０ｇ／リットルに調整した、無水クロム酸２５０ｇ
／リットル及び硫酸２．５ｇ／リットルよりなる通常の
サージェント浴に、陰極としてワークロール、陽極とし
て鉛を用いて、電流密度２５〜３５Ａ／ｄｍ2 、浴温４
５〜５５℃で２０分間電解処理を行い、ワークロールに
クロムめっき加工を行った。EXAMPLES Examples of the chromium plating method of the present invention will be described below. 1.0 to 1 metal impurity
250 g of chromic anhydride adjusted to 2.0 g / liter
In a normal Sargent bath consisting of 1 g / l and 2.5 g / l sulfuric acid, using a work roll as a cathode and lead as an anode, a current density of 25 to 35 A / dm 2 and a bath temperature of 4
Electrolytic treatment was performed at 5 to 55 ° C. for 20 minutes, and chromium plating was performed on the work roll.
【００１４】本実施例における金属不純物の溶け込み量
の管理は、１００００リットルの容量のタンク内におけ
るクロムめっき液中の金属不純物量が１２．０ｇ／リッ
トルとなった時に、このクロムめっき液を約８４０リッ
トル残して、残りの９１６０リットルを新液と入替え、
新液中の金属不純物量を１．００８ｇ／リットルとする
ことにより行った。そして、クロムめっき加工の継続中
は、クロムめっき液を循環して攪拌し、新液と古液の混
在によるクロムめっき液の不均一性をなくした。In this embodiment, the control of the amount of the metal impurities dissolved is such that when the amount of the metal impurities in the chromium plating solution in the tank having a capacity of 10,000 liters becomes 12.0 g / liter, the chromium plating solution is reduced to about 840 g / l. Liters, and replace the remaining 9160 liters with new liquid.
The test was carried out by adjusting the amount of metal impurities in the new solution to 1.008 g / liter. During the chrome plating process, the chromium plating solution was circulated and stirred to eliminate the non-uniformity of the chrome plating solution due to the mixture of the new solution and the old solution.
【００１５】その結果、継続して良好なクラック密度が
維持でき、めっき層の硬さも大きい状態を維持できるこ
ととなって、次の金属不純物の溶け込み量調整までの間
にワークロールのめっき層は剥離しなかった。[0015] As a result, a good crack density can be maintained continuously and the hardness of the plating layer can be maintained large, and the plating layer of the work roll is peeled off until the next adjustment of the amount of metal impurities to be dissolved. Did not.
【００１６】一方、金属不純物の溶け込み量の上限のみ
１２．０ｇ／リットルに調整して下限は規定せず、その
他は上記したのと同じ条件でワークロールにクロムめっ
き加工を行った場合には、クロムめっき液中の金属不純
物量が１２ｇ／リットル近くなり、タンク中のクロムめ
っき液を全て新液と入替えた当初の金属不純物が全くな
いか、０．１ｇ／リットル未満の場合は、液のなじみが
悪く、クラック密度が低下してめっき層の硬さが小さく
なるので、次の液替えまでの間に３回、めっき層の剥離
が発生した。図１は上記した本実施例の結果を示す図で
ある。On the other hand, when only the upper limit of the amount of dissolved metal impurities is adjusted to 12.0 g / liter and the lower limit is not specified, and the other conditions are the same as those described above, the work roll is subjected to chrome plating. If the amount of metal impurities in the chromium plating solution is close to 12 g / l and the chromium plating solution in the tank is completely replaced with a new solution and there are no metal impurities at all or less than 0.1 g / l, the solution is familiar. However, the crack density was reduced and the hardness of the plating layer was reduced, so that the plating layer was peeled off three times before the next liquid change. FIG. 1 is a diagram showing the results of the above-described embodiment.
【００１７】本実施例では、クロムめっき液中の金属不
純物量が１２ｇ／リットルとなった時に、このクロムめ
っき液を一部残して、残りを新液と入替え、新液中の金
属不純物量を１．００８ｇ／リットルとするものを示し
たが、新液中の金属不純物量は０．１〜１５ｇ／リット
ルの範囲で、廃液量等を考慮して適宜設定すればよい。In this embodiment, when the amount of metal impurities in the chromium plating solution reaches 12 g / liter, the chromium plating solution is partially left, and the remainder is replaced with a new solution. Although the amount is set to 1.008 g / liter, the amount of metal impurities in the new liquid is in the range of 0.1 to 15 g / liter and may be appropriately set in consideration of the amount of waste liquid and the like.
【００１８】[0018]
【発明の効果】以上説明したように、本発明のクロムめ
っき方法は、金属不純物の溶け込み量が０．１〜１５ｇ
／リットルと、上限のみならず下限までも規定している
ので、クロムめっきの品質として不安定な領域での加工
を回避でき、クロムめっき品質が継続して安定する。従
って、本発明のクロムめっき方法によれば、下限を規定
していなかった従来方法の場合に、液替え直後の液のな
じみが悪くクラック密度が低下することに起因して発生
していためっき層の剥離が皆無となる。As described above, according to the chromium plating method of the present invention, the amount of metal impurities dissolved is 0.1 to 15 g.
Since the upper limit as well as the lower limit are defined, the processing in an unstable region as the quality of chrome plating can be avoided, and the chrome plating quality is continuously stabilized. Therefore, according to the chromium plating method of the present invention, in the case of the conventional method in which the lower limit is not specified, the plating layer which is generated due to poor adaptation of the solution immediately after the liquid change and a decrease in crack density is reduced. There is no peeling.
【００１９】そして、本発明のクロムめっき方法では、
金属不純物の溶け込み量の調整を、クロムめっき液の一
部を入れ替えることによって行うので、廃液が減少し
て、資源の有効利用が図れると共に、廃液処理に要する
費用も削減できる。[0019] Then, in the chromium plating method of the present invention,
The adjustment of the penetration amount of the metal impurities, the line by replacing a portion of the chromium plating solution Unode, waste is reduced, with can be effectively utilize resources, cost for waste liquid treatment can be reduced.
【図１】本発明のクロムめっき方法を使用した場合と、
従来のクロムめっき方法を使用した場合のめっき剥離発
生件数を比較した図である。FIG. 1 shows a case where the chromium plating method of the present invention is used,
It is the figure which compared the number of times of plating exfoliation when the conventional chrome plating method was used.
【図２】クロムめっき液中の鉄分量と電流効率、硬さ、
クラック密度の関係を示す図である。Fig. 2 Iron content in chromium plating solution and current efficiency, hardness,
It is a figure which shows the relationship of a crack density.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大地 正義 和歌山県和歌山市湊1850番地 住友金属 工業株式会社 和歌山製鉄所内 (56)参考文献 特開 昭51−9032（ＪＰ，Ａ) 特開 昭56−96100（ＪＰ，Ａ) 特開 昭58−93885（ＪＰ，Ａ) 特開 平９−165699（ＪＰ，Ａ) 特開 昭55−34606（ＪＰ，Ａ) 特開 昭53−110930（ＪＰ，Ａ) 特開 昭49−97732（ＪＰ，Ａ) 特開 昭48−79735（ＪＰ，Ａ) 特開 平７−233500（ＪＰ，Ａ) 実開 昭58−131963（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) C25D 3/04 C25D 21/14 - 21/18 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Masayoshi Daichi 1850 Minato, Wakayama-shi, Wakayama Sumitomo Metal Industries, Ltd. Wakayama Works (56) References JP-A-51-9302 (JP, A) JP-A-56- 96100 (JP, A) JP-A-58-93885 (JP, A) JP-A-9-165699 (JP, A) JP-A-55-34606 (JP, A) JP-A-53-110930 (JP, A) JP-A-49-97732 (JP, A) JP-A-48-79735 (JP, A) JP-A-7-233500 (JP, A) Japanese Utility Model Showa 58-131963 (JP, U) (58) Fields investigated (Int.Cl. 7 , DB name) C25D 3/04 C25D 21/14-21/18
Claims (1)
替えることにより、金属不純物の溶け込み量が０．１〜
１５ｇ／リットルに調整したクロムめっき液を使用する
ことを特徴とするクロムめっき方法。At the time of liquid change, a part of the chrome plating solution is put in.
By changing, the amount of metal impurities
A chromium plating method using a chromium plating solution adjusted to 15 g / liter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32675196A JP3230445B2 (en) | 1996-12-06 | 1996-12-06 | Chrome plating method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32675196A JP3230445B2 (en) | 1996-12-06 | 1996-12-06 | Chrome plating method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10158882A JPH10158882A (en) | 1998-06-16 |
| JP3230445B2 true JP3230445B2 (en) | 2001-11-19 |
Family
ID=18191285
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32675196A Expired - Fee Related JP3230445B2 (en) | 1996-12-06 | 1996-12-06 | Chrome plating method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3230445B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6495949B1 (en) | 1999-11-03 | 2002-12-17 | Orion Electric Co., Ltd. | Electron tube cathode |
-
1996
- 1996-12-06 JP JP32675196A patent/JP3230445B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6495949B1 (en) | 1999-11-03 | 2002-12-17 | Orion Electric Co., Ltd. | Electron tube cathode |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10158882A (en) | 1998-06-16 |
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