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RoHs and stainless steel

2005

Stainless steel has Chromium as one of its composition materials.What will be the state of chromium in stainless steel? Under what circumstances the valency state in Stainless steel will change?
and
What will be state of Chromium in plated condition? and if it is in Hexavalent state , how to convert it into Trivalent state?

Sureshkumar
NUS - Singapore

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2005

Hello,

This has been covered a few times in the archives, so I'll leave the details in those letters (the search engine can find them pretty quickly for you).

Basically what it breaks down to is this - chromium in the metallic form is in the 0 valence state; this is true whether it is plated on or in an alloy like stainless steel. This is also true regardless what the valence state was prior to becoming metallic - so the type of plating bath doesn't matter.

Chromium contained in chromate coatings MAY be in the hex state, but then it does depend on the type of bath and the specific coating.

Good luck.

Jim Gorsich
Compton, California, USA

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