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Eco-friendly Passivation on stainless steel 304 with black or white appearance

Hi,

please help me out with advice regarding Passivation on the 304 Stainless steel which shall be Eco-friendly and at the same time it should pass the H2SO4 acid resistance test for 24 Hrs. Looking to shift away from chrome process.

Thanks,

Hi, Kesava. "Eco-friendly" is a subjective and non-scientific term, but there are proprietary passivation solutions which do not use nitric acid -- and nitric acid is rather noxious stuff.

In most environments and embodiments, though, passivated 304 stainless steel will not be as attractive or rust-free as high quality chrome plating.

Regards,

I'm not sure if by "chrome process" you mean a nitric passivation bath with dichromate (which as an additive to a nitric bath is used with many grades of stainless, though not normally with 304) or chrome plating (which usually uses something other than stainless steel as a substrate).

However Ted is quite correct, non-hazardous alternatives are readily available for passivating all grades of stainless. Let us know if we can help.

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