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Is Chrome passivation needed after zinc phosphating?
Q. There are generally 5 stages pre-treatment process for Galvanised steel. (Cleaner, rinse, Zinc phosphate, rinse, Chrome passivation). I came to know that people face some finishing problems after stage 5 i.e., Chrome passivation. What is the drawback of using Chemical treatment i.e., chrome passivation stage?Dannu Malpani
agra university - Agra, UP, India
A. Hi Dannu. Chrome post dips (final rinses) are excellent from a performance standpoint, but they leave hexavalent chromium (a carcinogenic toxin) on the part.
Luck & Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey