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Hard chrome plating on Valve steel - weather it is Hexavalent or not

Dears,
I would like to know, the hard chrome we plated on Valve steel surface is Hexavalent or not. Is there any testing methods like SEM or XRD to test this.

Natesha
Varroc - India
2006

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It is chrome metal, valence 0, it is not hexavalent. The only caution is that, since the plating solution itself is hexavalent chrome, it must be thoroughly rinsed off.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

I caveat to Ted's reply: the rinse water needs to be free of hex chrome either by water flow or the use of a reducer/post plate additive.

Gene Packman
process supplier - Great Neck, New York
2006

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I am a technician working on paper coatings and recently had a piece of metal chrome plated to mimic a cast coating drum. In the chrome-plating process is there a chance that some residual Cr-6 is still on the piece? Or are they usually cleaned pretty thoroughly before the make it out to those of us purchasers?

Thanks,

Chris Martin
Paper Coatings - Escondido, California, USA
2006

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2006

Hex chrome, which is amber in color, is visible at very low concentration. So if the parts appear bright and metallic color, they were probably well rinsed.

Nonetheless, I have seen small hard chrome plated chain components which got one quick dip in highly contaminated rinse water, and then a spin dry, and they were shipped that way. So a spec and a periodic check is a good idea.

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