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Will blue chromate compromise powder coating?

Hi..

If my material (mild steel ASTM A36) is going to be blue-chromized (DIN 50941/FeZn8b), will it affect a later powder coating process..?

and with the blue chromized, will the effectiveness of pre-treatment (i.e. thin iron phosphating) be compromised..?

thanks..!

Vincent Tan
biomedical devices - Singapore
2004

Blue chromating, and the spec you referenced, imply zinc plating before the chromating, Vincent. In this case you zinc plate and blue chromate in lieu of phosphating, not in addition to it. Iron phosphating is a fine pretreatment, but it cannot be applied to a zinc plated surface, and phosphatizing cannot equal the corrosion resistance of zinc plus chromate as a pretreatment anyway.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Ted is available for instant help
or longer-term assistance.
2004

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