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Chemical polishing between nitriding and plating

Hi, I am having a problem of determining the usage of chemical polishing before parts go for plating.

I had a part that goes through nitriding process, and continued to plate with Sulfamate Nickel over copper flash.
As per plating industry, they need to be dipped into chemical polish before proceeding to plating to clean the surface.

I am not sure if using the chemical polish can erode the nitriding layer from base cold rolled steel.

Please advise

Saiful Hafizam Alias
Engineer - Bayan Lepas, Penang, Malaysia
May 6, 2011

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May 2011

Hi, Saiful.

Was there a language translation involved somewhere in the history of this question? Because I think a problem here is that people are using different words to describe processes. In the USA, speaking in the colloquial English of electroplaters, "chemical polishing" would mean an immersion in strong acid that dissolves some portion of the metal on the surface. But that is not typically required before plating most parts. Rather, what is required is alkaline cleaning "to clean the surface", which I would not expect to harm a nitrided surface.

But on the other hand, I am not sure that it is practical to nickel plate a nitrided surface with adequate adhesion without polishing it first. Maybe if we can sort out the exact problem, then someone with more experience than me can guide you.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey