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  for Metal Finishing since 1989
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Pitting nickel plating

2004

We have nickel sulfamate bath. My problem are pitting occur around topside of workpiece. Worker check air agitator is OK. PH. 4.0 ,solution analysis NiSO4 230 g/l ,NiCl 35 g/l, Boric 34 g/l. This solution use about 5 year. But we maintenance always. Now ,we try to add hydrogen peroxide 0.1 cc/l then agitation 30 min and continuous filter by cartridge carbon. This problem is still have. So we try it again. But this problem not yet OK. How do we do?

Thank you.

Tawatchai Sujitranuruk
plating engineer - Bangkok, Thailand

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First of two simultaneous responses --

It could be due to numerous things, but the most likely are a lack of surfactant and/or particulate contamination. What additives are in the electrolyte?

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004

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Second of two simultaneous responses -- 2004

Tawatchai,

Hydrogen peroxide doesn't work with temperatures higher than 50 °C (peroxide has a short oxidizing time at this temperature). See if you have some dirty dust over the plating tank. Hydrogen peroxide is for removing of iron in the solution. If you think this pitting is from iron contamination you should do a pH treatment with hydrogen peroxide. Regards,

Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden

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2004

Tawatchai.

Please check

1) The air agitation.
2) The level of iron .. if the walls are yellow inside its likely to be iron. Follow the procedure outlined in another reply.
3) Pitting can also occur from excess Nickel Brightener and unbalances carrier adds.
4) Oil. Nitrates and organic impurities are other causes.

I would suggest you contact a local chemical supplier.

Regards,

Asif Nurie [deceased]
- New Delhi, India
With deep regret we sadly advise that Asif passed away on Jan 24, 2016

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April 26, 2009

I accept the others suggestion and also you don't have to forget current density maybe you use it high and also suggest you use Lauryl sulphate sodium
goooooooood luck
Amir.

Amir sadeghi
student - Tehran