JPH062955B2 - Method for improving corrosion resistance of chromium-molybdenum alloy plating film - Google Patents
Method for improving corrosion resistance of chromium-molybdenum alloy plating filmInfo
- Publication number
- JPH062955B2 JPH062955B2 JP13830888A JP13830888A JPH062955B2 JP H062955 B2 JPH062955 B2 JP H062955B2 JP 13830888 A JP13830888 A JP 13830888A JP 13830888 A JP13830888 A JP 13830888A JP H062955 B2 JPH062955 B2 JP H062955B2
- Authority
- JP
- Japan
- Prior art keywords
- plating film
- alloy plating
- aqueous solution
- film
- corrosion resistance
- 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
- 238000007747 plating Methods 0.000 title claims description 67
- 238000005260 corrosion Methods 0.000 title claims description 17
- 230000007797 corrosion Effects 0.000 title claims description 17
- 238000000034 method Methods 0.000 title claims description 10
- 229910001182 Mo alloy Inorganic materials 0.000 title claims description 6
- VNTLIPZTSJSULJ-UHFFFAOYSA-N chromium molybdenum Chemical compound [Cr].[Mo] VNTLIPZTSJSULJ-UHFFFAOYSA-N 0.000 title claims 3
- 239000007864 aqueous solution Substances 0.000 claims description 31
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 13
- 229910017604 nitric acid Inorganic materials 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 11
- 229910052760 oxygen Inorganic materials 0.000 claims description 11
- 239000001301 oxygen Substances 0.000 claims description 11
- 239000002253 acid Substances 0.000 claims description 8
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims description 3
- 239000011733 molybdenum Substances 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 description 42
- 239000000956 alloy Substances 0.000 description 42
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 34
- 230000002378 acidificating effect Effects 0.000 description 7
- 238000002161 passivation Methods 0.000 description 7
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 6
- 238000007654 immersion Methods 0.000 description 6
- 229910052804 chromium Inorganic materials 0.000 description 5
- 239000011651 chromium Substances 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 239000011734 sodium Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 230000004580 weight loss Effects 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 230000003213 activating effect Effects 0.000 description 2
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 2
- 150000002751 molybdenum Chemical class 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 235000015393 sodium molybdate Nutrition 0.000 description 2
- 239000011684 sodium molybdate Substances 0.000 description 2
- TVXXNOYZHKPKGW-UHFFFAOYSA-N sodium molybdate (anhydrous) Chemical compound [Na+].[Na+].[O-][Mo]([O-])(=O)=O TVXXNOYZHKPKGW-UHFFFAOYSA-N 0.000 description 2
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004453 electron probe microanalysis Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 239000002349 well water Substances 0.000 description 1
- 235000020681 well water Nutrition 0.000 description 1
Landscapes
- Chemical Treatment Of Metals (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、モリブデン含量が１０重量％以下のクロム−
モリブデン（Ｃｒ−Ｍｏ）合金めっき皮膜の耐食性向上
方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a chromium-containing molybdenum content of 10% by weight or less.
The present invention relates to a method for improving the corrosion resistance of a molybdenum (Cr-Mo) alloy plating film.
Ｃｒ−Ｍｏ合金めっき皮膜、特にＭｏを１０％（重量
％、以下同じ）以下含有する合金めっき皮膜は、クロム
酸を主成分とし、これにモリブデン酸ナトリウム等のモ
リブデン塩を添加しためっき浴から電析することがで
き、得られたＣｒ−Ｍｏ合金めっき皮膜は良好な光沢を
示すが、硫酸水溶液中に浸漬すると皮膜が溶解し、比較
的短時間で消失するという問題があり、耐食性が悪いも
のであった。A Cr-Mo alloy plating film, particularly an alloy plating film containing 10% (wt%, the same applies hereinafter) or less of Mo contains chromic acid as a main component, and a molybdenum salt such as sodium molybdate is added to the plating bath to obtain an electric charge. The resulting Cr-Mo alloy plating film has good gloss, but when immersed in an aqueous sulfuric acid solution, there is a problem that the film dissolves and disappears in a relatively short time. Met.
このため、従来はかかるＣｒ−Ｍｏ合金めっき皮膜の耐
食性を向上させるため、Ｃｒ−Ｍｏ合金めっき皮膜上に
更にポーラスクロムめっきを施すことが行なわれてい
た。Therefore, conventionally, in order to improve the corrosion resistance of the Cr-Mo alloy plating film, porous chromium plating is further performed on the Cr-Mo alloy plating film.
しかし、Ｃｒ−Ｍｏ合金めっき後、更にポーラスクロム
めっきを行なうことは、２度手間となって時間と費用を
要する上、Ｃｒ−Ｍｏ合金めっき皮膜上に別のめっき皮
膜を形成するので、Ｃｒ−Ｍｏ合金めっき皮膜の特性が
十分生かされないという問題があった。However, performing further porous chrome plating after Cr-Mo alloy plating requires time and cost twice, and since another plating film is formed on the Cr-Mo alloy plating film, Cr- There is a problem that the characteristics of the Mo alloy plating film are not fully utilized.
本発明は上記事情を改善するためになされたもので、従
来のようにＣｒ−Ｍｏ合金めっき皮膜上にポーラスクロ
ムめっきを施すことにより該ポーラスクロムめっき皮膜
の作用で間接的にＣｒ−Ｍｏ合金めっき皮膜の耐食性を
向上するという方法とは全く異なり、Ｃｒ−Ｍｏ合金め
っき皮膜自体の耐食性を直接的に向上する方法を提供す
ることを目的とする。The present invention has been made in order to improve the above-mentioned circumstances. As in the prior art, by performing porous chromium plating on a Cr-Mo alloy plating film, Cr-Mo alloy plating is indirectly performed by the action of the porous chromium plating film. It is an object of the present invention to provide a method of directly improving the corrosion resistance of the Cr-Mo alloy plating film itself, which is completely different from the method of improving the corrosion resistance of the film.
本発明者らは。上記目的を達成するため鋭意検討を行な
った結果、Ｍｏ含量が１０％以下のＣｒ−Ｍｏ合金めっ
き皮膜をまず硫酸水溶液や塩酸水溶液等の酸濃度が0.5
〜１０％である還元性酸性水溶液に浸漬してＣｒ−Ｍｏ
合金めっき皮膜表面を活性化し、次いで、この活性化さ
れたＣｒ−Ｍｏ合金めっき皮膜を溶存酸素を含む水又は
硝酸濃度が１〜50％である硝酸水溶液に浸漬することに
より、Ｃｒ−Ｍｏ合金めっき皮膜が不動態化し、その後
硫酸水溶液に浸漬しても最早皮膜が速やかに溶解すると
いう問題が生じることがなく、優れた耐食性を示すこと
を知見した。しかも、かかる活性化−不動態化処理を行
なっても、Ｃｒ−Ｍｏ合金めっき皮膜の光沢が維持さ
れ、耐摩耗性や硬度等の皮膜物性も損なわれることがな
く、かかる耐食性向上処理がＭｏを１０％以下の割合で
含有する光沢Ｃｒ−Ｍｏ合金めっき皮膜に有効に採用さ
れることを見い出し、本発明をなすに至ったものであ
る。The inventors. As a result of intensive studies to achieve the above object, as a result, a Cr-Mo alloy plating film having a Mo content of 10% or less was first obtained with an acid concentration of 0.5% sulfuric acid or hydrochloric acid.
Immersed in a reducing acidic aqueous solution of 10% to Cr-Mo
Cr-Mo alloy plating is performed by activating the surface of the alloy plating film and then immersing the activated Cr-Mo alloy plating film in water containing dissolved oxygen or a nitric acid aqueous solution having a nitric acid concentration of 1 to 50%. It has been found that the film is passivated, and even if the film is subsequently immersed in a sulfuric acid aqueous solution, the problem that the film is quickly dissolved no longer occurs, and excellent corrosion resistance is exhibited. Moreover, even if such activation-passivation treatment is performed, the luster of the Cr-Mo alloy plating film is maintained, and the physical properties of the coating such as wear resistance and hardness are not impaired. The present invention has been completed by finding that it is effectively used for a bright Cr-Mo alloy plating film containing 10% or less.
以下、本発明につき更に詳しく説明する。Hereinafter, the present invention will be described in more detail.
本発明に係るＣｒ−Ｍｏ合金めっき皮膜の耐食性向上方
法は、Ｍｏ含量が１０％以下のＣｒ−Ｍｏ合金めっき皮
膜を酸の濃度が0.5〜10％の還元性酸性水溶液中に浸漬
し該皮膜を活性化した後、溶存酸素を含む水又は硝酸濃
度が１〜50％の硝酸水溶液中に浸漬して該皮膜を不動態
処理したものである。A method for improving the corrosion resistance of a Cr-Mo alloy plating film according to the present invention is a method of immersing a Cr-Mo alloy plating film having a Mo content of 10% or less in a reducing acidic aqueous solution having an acid concentration of 0.5 to 10%. After activation, the film is passivated by immersing it in water containing dissolved oxygen or a nitric acid aqueous solution having a nitric acid concentration of 1 to 50%.
ここで、Ｍｏ含量が10％以下のＣｒ−Ｍｏ合金めっき皮
膜としては、公知の方法で得られたいずれのＣｒ−Ｍｏ
合金めっき皮膜であってもよいが、本発明はＭｏ含量が
１０％以下、とりわけ０．０５〜５％、更に言えば０．
３〜３％のものに対して好適に採用される。Here, as the Cr-Mo alloy plating film having a Mo content of 10% or less, any Cr-Mo alloy obtained by a known method is used.
It may be an alloy plating film, but in the present invention, the Mo content is 10% or less, particularly 0.05 to 5%, more specifically, 0.
It is preferably used for 3 to 3%.
なお、かかるＭｏ含量が１０％以下のＣｒ−Ｍｏ合金め
っき皮膜は、特に制限されるものではないが、例えばク
ロム酸を１５０〜３５０ｇ／、硫酸を１〜５ｇ／、
モリブデン酸ナトリウム等のモリブデン塩を５０〜３０
０ｇ／含有するめっき浴を用い、温度３５〜６５℃、
陰極電流密度１０〜１５０Ａ／ｄm2でめっきすることに
より得ることができる。The Cr-Mo alloy plating film having a Mo content of 10% or less is not particularly limited, but for example, chromic acid is 150 to 350 g /, sulfuric acid is 1 to 5 g /,
Add 50 to 30 molybdenum salts such as sodium molybdate.
0 g / containing plating bath, temperature 35 ~ 65 ℃,
It can be obtained by plating with a cathode current density of 10 to 150 A / dm 2 .
本発明は、上記のＣｒ−Ｍｏ合金めっき皮膜をまず還元
性酸性水溶液に浸漬して皮膜表面を活性化する。In the present invention, the Cr-Mo alloy plating film is first immersed in a reducing acidic aqueous solution to activate the film surface.
この場合、還元性酸性水溶液としては、硫酸、塩酸やこ
れらの混酸の水溶液が好適に使用されるが、これに限定
されるものではなく、Ｃｒ−Ｍｏ合金めっき皮膜を溶
解、活性化し得るいずれの酸の水溶液も使用することが
できる。酸の濃度は０．５〜１０％、特に３〜５％が好
ましい。また、還元性酸性水溶液へのＣｒ−Ｍｏ合金め
っき皮膜の浸漬条件としては、温度１０〜６０℃、特に
３０〜５０℃が好適であり、浸漬時間は酸濃度や液温な
どにより相違するが、通常５秒〜５分、特に１０秒〜３
分、最適には３０秒〜２分である。ここで、浸漬時間が
あまり短いとＣｒ−Ｍｏ合金めっき皮膜が十分活性化さ
れず、このため後工程において十分な不動態化がなされ
ない場合が生じ、一方浸漬時間が長すぎると皮膜の溶解
量が大きくなり、皮膜が薄くなるので、これらの点を考
慮して浸漬時間を決定するのが好ましい。In this case, an aqueous solution of sulfuric acid, hydrochloric acid or a mixed acid thereof is preferably used as the reducing acidic aqueous solution, but the reducing acidic aqueous solution is not limited thereto, and any solution capable of dissolving and activating the Cr-Mo alloy plating film is used. Aqueous solutions of acids can also be used. The acid concentration is preferably 0.5 to 10%, particularly preferably 3 to 5%. Further, as a condition for immersing the Cr-Mo alloy plating film in the reducing acidic aqueous solution, a temperature of 10 to 60 ° C, particularly 30 to 50 ° C is suitable, and the immersing time varies depending on the acid concentration and the liquid temperature. Usually 5 seconds to 5 minutes, especially 10 seconds to 3
Minutes, optimally 30 seconds to 2 minutes. Here, if the immersion time is too short, the Cr-Mo alloy plating film is not sufficiently activated, and therefore, there is a case where sufficient passivation is not performed in the subsequent step, while if the immersion time is too long, the dissolution amount of the film Is larger and the coating is thinner, it is preferable to determine the immersion time in consideration of these points.
次に、本発明においては、上記のようにして活性化され
たＣｒ−Ｍｏ合金めっき皮膜を水又は硝酸水溶液中に浸
漬する不動態処理を施す。Next, in the present invention, a passivation treatment is performed in which the Cr-Mo alloy plating film activated as described above is immersed in water or a nitric acid aqueous solution.
この場合、水は溶存酸素を大気中飽和以下、特に３〜７
ppm含むものが好ましいが、水の種類としては蒸留水、
イオン交換水、水道水、井戸水等のいずれのものでもよ
い。また、硝酸水溶液としては、硝酸濃度が１〜５０
％、特に１〜３０％のものが好適である。浸漬条件とし
ては、温度１０〜７０℃、特に３０〜５０℃が好適に採
用され、また浸漬時間は３０秒〜５分、特に１〜２分が
好ましい。In this case, water dissolves dissolved oxygen in the atmosphere to a saturation level or less, particularly 3 to 7
Although it is preferable to include ppm, distilled water is used as the type of water.
Any of ion-exchanged water, tap water, well water, etc. may be used. The nitric acid aqueous solution has a nitric acid concentration of 1 to 50.
%, Particularly 1 to 30% is preferable. As the immersion conditions, a temperature of 10 to 70 ° C., particularly 30 to 50 ° C. is preferably adopted, and an immersion time of 30 seconds to 5 minutes, particularly 1 to 2 minutes is preferable.
以上のように不動態処理されたＣｒ−Ｍｏ合金めっき皮
膜は、耐食性が顕著に向上し、例えば５％硫酸水溶液に
６０℃で１００時間浸漬しても溶解減が極めて少ないも
のである。The Cr-Mo alloy plating film, which has been passivated as described above, has significantly improved corrosion resistance, and for example, even if it is immersed in a 5% sulfuric acid aqueous solution at 60 ° C. for 100 hours, the reduction in dissolution is extremely small.
本発明によれば、Ｃｒ−Ｍｏ合金めっき皮膜上に他のめ
っき皮膜を形成することにより間接的に耐食性の向上を
計るものとは全く異なり、単に還元性酸性水溶液、水又
は硝酸水溶液に浸漬するという簡単な操作でしかもコス
ト的にも安価に直接的にＭｏ含量が１０％以下のＣｒ−
Ｍｏ合金めっき皮膜の耐食性を向上させることができ、
かつ元のＣｒ−Ｍｏ合金めっき皮膜の光沢や耐摩耗性、
硬度等の皮膜物性を維持し、その特性を十分発揮させる
ことができる。According to the present invention, completely different from what indirectly improves the corrosion resistance by forming another plating film on the Cr-Mo alloy plating film, it is simply immersed in a reducing acidic aqueous solution, water or nitric acid aqueous solution. It is a simple operation, and the cost is low.
It is possible to improve the corrosion resistance of the Mo alloy plating film,
And the gloss and wear resistance of the original Cr-Mo alloy plating film,
The physical properties of the film such as hardness can be maintained and the properties can be sufficiently exhibited.
以下、実施例と比較例を示し、本発明を具体的に説明す
るが、本発明は下記の実施例に制限されるものでない。Hereinafter, the present invention will be specifically described by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.
〔実施例１〕 下記組成のＣｒ−Ｍｏ合金めっき浴を用い、下記のめっ
き条件により前処理（脱脂、酸洗）した銅板上にＭｏを
１％含有するＣｒ−Ｍｏ合金めっき皮膜を形成した。[Example 1] Using a Cr-Mo alloy plating bath having the following composition, a Cr-Mo alloy plating film containing 1% of Mo was formed on a copper plate pretreated (degreased and pickled) under the following plating conditions.
浴 組 成 ＣｒＯ3 ３００ ｇ／ Ｈ2ＳＯ4 ３ 〃 シュウ酸 ５．２ 〃 Ｎa2ＭoＯ4・２Ｈ2Ｏ ７５ 〃 めっき条件 浴温度 ４０〜６０℃ 陰極電流密度 ５０Ａ／ｄm2 陰 極 銅板（３０×３４×０．３mm） 陽 極 白金網（３５×８５mm） めっき時間 ６０分 膜 厚 〜３１．５μm 次に、上記のようにして銅板上に形成したＣｒ−Ｍｏ合
金めっき皮膜を６０℃、５％硫酸水溶液中に１分間浸漬
して該めっき皮膜表面を活性化した後、溶存酸素を含む
水（溶存酸素量７ppm）又は１０％硝酸水溶液中に室温
で第１表に示す時間浸漬する不動態化処理を施した。Bath set formed CrO 3 300 g / H 2 SO 4 3 〃 oxalate 5.2 〃 Na 2 M o O 4 · 2H 2 O 75 〃 plating conditions bath temperature 40 to 60 ° C. Cathode current density 50A / dm 2 negative pole copper (30 × 34 × 0.3 mm) Cathode Platinum mesh (35 × 85 mm) Plating time 60 minutes Film thickness ˜31.5 μm Next, the Cr—Mo alloy plating film formed on the copper plate as described above was applied at 60 ° C. After immersing in 5% sulfuric acid aqueous solution for 1 minute to activate the surface of the plating film, it is immersed in water containing dissolved oxygen (dissolved oxygen amount 7 ppm) or 10% nitric acid aqueous solution at room temperature for the time shown in Table 1. It was passivated.
次いで、このめっき皮膜を５％硫酸水溶液中に６０℃で
１００時間浸漬し、その腐食減量を測定した。結果を第
１表に示す。Next, this plating film was immersed in a 5% sulfuric acid aqueous solution at 60 ° C. for 100 hours, and its corrosion weight loss was measured. The results are shown in Table 1.
〔実施例２〕 めっき浴中のＮa2ＭoＯ4・２Ｈ2Ｏ量を１２５ｇ／と
した以外は実施例１と同様にしてＣｒ−Ｍｏ合金めっき
皮膜（Ｍｏ量２．０％）を形成し、次いで６０℃、５％
硫酸水溶液中に１分間浸漬した後、溶存酸素を含む水
（溶存酸素量７ppm）に室温で第２表に示す時間浸漬し
た。次に、この不動態化処理が施されたＣｒ−Ｍｏ合金
めっき皮膜を５％硫酸水溶液中に６０℃で１００時間浸
漬し、その腐食減量を測定した。結果を第２表に示す。 Form Example 2 Na 2 M o O 4 · 2H 2 O amount except for using 125 g / in the same manner as in Example 1 Cr-Mo alloy plating film in the plating bath (Mo amount of 2.0%) Then 60 ° C, 5%
After being immersed in an aqueous solution of sulfuric acid for 1 minute, it was immersed in water containing dissolved oxygen (dissolved oxygen amount 7 ppm) at room temperature for the time shown in Table 2. Next, this passivated Cr-Mo alloy plating film was immersed in a 5% sulfuric acid aqueous solution at 60 ° C for 100 hours, and its corrosion weight loss was measured. The results are shown in Table 2.
〔実施例３〕 めっき浴中のＮa2ＭoＯ4・２Ｈ2Ｏ量を７５ｇ／と
し、めっき温度を５０℃とした以外は実施例１と同様に
してＣｒ−Ｍｏ合金めっき皮膜（Ｍｏ量０．４％）を形
成し、次いで６０℃，５％硫酸水溶液中に１分間浸漬し
た後、第３表に示す濃度の硝酸水溶液中に室温で３分間
浸漬した。次に、この不動態化処理が施されたＣｒ−Ｍ
ｏ合金めっき皮膜を５％硫酸水溶液中に６０℃で１００
時間浸漬し、その腐食減量を測定した。結果を第３表に
示す。 Example 3 Na 2 M in the plating bath o O 4 · 2H 2 O amount was a 75 g /, except that the plating temperature of 50 ° C. in the same manner as in Example 1 Cr-Mo alloy plating film (Mo amount 0.4%) and then immersed in a 5% sulfuric acid aqueous solution at 60 ° C. for 1 minute and then in a nitric acid aqueous solution having the concentration shown in Table 3 at room temperature for 3 minutes. Next, Cr-M that has been subjected to this passivation treatment
o Alloy plating film 100 at 60 ℃ in 5% sulfuric acid aqueous solution
It was immersed for a period of time and its corrosion weight loss was measured. The results are shown in Table 3.
〔実施例３〕 めっき浴中のＮa2ＭoＯ4・２Ｈ2Ｏ量を１７０ｇ／と
した以外は実施例１と同様にしてＣｒ−Ｍｏ合金めっき
皮膜（Ｍｏ量１．７％）を形成し、次いで５％量硫酸水
溶液中に第４表に示す時間浸漬し該めっき皮膜表面を活
性化した後、溶存酸素を含む水（溶存酸素量７ppm）に
室温で１分間浸漬した。次に、この不動態処理が施され
たＣｒ−Ｍｏ合金めっき皮膜を５％硫酸水溶液中に６０
℃で１００時間浸漬し、その腐食減量を測定した。結果
を第４表に示す。 Example 3 form Na 2 M o O 4 · 2H 2 except that O amount was 170 g / in the same manner as in Example 1 Cr-Mo alloy plating film in the plating bath (Mo amount of 1.7%) Then, after immersing in a 5% sulfuric acid aqueous solution for the time shown in Table 4 to activate the surface of the plating film, it was immersed in water containing dissolved oxygen (dissolved oxygen amount 7 ppm) at room temperature for 1 minute. Next, the Cr-Mo alloy plating film subjected to the passivation treatment is added to a 60% aqueous solution of sulfuric acid to 60%.
It was immersed at 100 ° C. for 100 hours, and its corrosion weight loss was measured. The results are shown in Table 4.
以上の結果により、本発明の処理がなされたＣｒ−Ｍｏ
合金めっき皮膜は優れた耐食性を有することが認められ
た。 Based on the above results, the Cr-Mo processed by the present invention
It was found that the alloy plating film has excellent corrosion resistance.
なお、上記のように硫酸水溶液で活性化され、次いで溶
存酸素を含む水や硝酸水溶液で不動態処理が施されたＣ
ｒ−Ｍｏ合金めっき皮膜を原子吸光分析法、ＥＰＭＡ
法、オーゼ分光分析法などを用いて分析した結果、当該
めっき皮膜表面にはクロムを主成分とする不動態皮膜が
形成されていることが明らかにされた。As described above, C activated by an aqueous sulfuric acid solution and then subjected to a passivation treatment with an aqueous solution containing dissolved oxygen or an aqueous nitric acid solution.
r-Mo alloy plating film, atomic absorption spectrometry, EPMA
As a result of an analysis using a method, an Auze spectroscopy method, etc., it was revealed that a passivation film containing chromium as a main component was formed on the surface of the plating film.
また、本発明の方法により処理されたＣｒ−Ｍｏ合金め
っき皮膜は、梨地状にならず、いずれも良好な光沢を有
し、しかも高耐摩耗性を示すと共に、５％硫酸水溶液浸
漬試験（３０〜６０℃，１００時間）、５％硫酸水溶液
中の陽分極曲線（３０℃），３％食塩水中孔食電位（３
０℃）の結果からも優れた耐食性を示すことが認められ
た。In addition, the Cr-Mo alloy plating film treated by the method of the present invention does not have a satin finish, has good gloss, and exhibits high wear resistance, and a 5% sulfuric acid aqueous solution immersion test (30 -60 ° C, 100 hours), anodic polarization curve in 5% sulfuric acid aqueous solution (30 ° C), pitting potential in 3% saline solution (3
It was also confirmed from the result of 0 ° C.) that excellent corrosion resistance was exhibited.
Claims (1)
ロム−モリブデン合金めっき皮膜を酸の濃度が0.5〜10
重量％の還元性酸性水溶液中に浸漬して該皮膜を活性化
した後、溶存酸素を含む水又は硝酸濃度が１〜50重量％
である硝酸水溶液中に浸漬して該皮膜を不動態処理する
ことを特徴とするクロム−モリブデン合金めっき皮膜の
耐食性向上方法。1. A chromium-molybdenum alloy plating film having a molybdenum content of 10% by weight or less and an acid concentration of 0.5-10.
After immersing in a reducing acid aqueous solution of weight% to activate the film, the concentration of water containing dissolved oxygen or nitric acid is 1 to 50% by weight.
A method for improving the corrosion resistance of a chromium-molybdenum alloy plating film, which comprises immersing the film in a nitric acid aqueous solution to passivate the film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13830888A JPH062955B2 (en) | 1988-06-07 | 1988-06-07 | Method for improving corrosion resistance of chromium-molybdenum alloy plating film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13830888A JPH062955B2 (en) | 1988-06-07 | 1988-06-07 | Method for improving corrosion resistance of chromium-molybdenum alloy plating film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01309976A JPH01309976A (en) | 1989-12-14 |
| JPH062955B2 true JPH062955B2 (en) | 1994-01-12 |
Family
ID=15218842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13830888A Expired - Lifetime JPH062955B2 (en) | 1988-06-07 | 1988-06-07 | Method for improving corrosion resistance of chromium-molybdenum alloy plating film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH062955B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104259978A (en) * | 2012-11-23 | 2015-01-07 | 江苏顺发电热材料有限公司 | Electrical heated tube tumbling process with passivating step |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011214632A (en) * | 2010-03-31 | 2011-10-27 | Hitachi Automotive Systems Ltd | Disc brake |
| CN104149016A (en) * | 2012-11-23 | 2014-11-19 | 江苏顺发电热材料有限公司 | Treatment process for electric heating pipe |
-
1988
- 1988-06-07 JP JP13830888A patent/JPH062955B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104259978A (en) * | 2012-11-23 | 2015-01-07 | 江苏顺发电热材料有限公司 | Electrical heated tube tumbling process with passivating step |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01309976A (en) | 1989-12-14 |
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