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Zinc and Yellow Trivalent Plating

I'm having trouble finding someone available to rack plate a small steel part to ASTM B633 - Zinc plate with yellow chromate using Trivalent chromium. No Cr6+ allowed. I understand platers are moving in this direction to meet US automakers move to eliminate Cr6+ usage next year.

I would appreciate any assistance.

Greg Carrico
- Hanover Park, Illinois

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Zinc platings with trivalent chromates are usually clear, not yellow. The only platers I know that do trivalent chrome run clear only. You should consider updating your requirements. I have heard of some trivalent yellow products out there, but I do not know if they work well or are used in production.

Tim Neveau
Rochester Hills, Michigan
 

Hi,

The Tri-Valent chromates used to meet the specifications laid down by the various motor companies are clear in color (perhaps sometimes exhibiting a little iridesence) but the corrosion resistance is claimed to be as good as the yellow Cr 6+ chromates , and tests have shown that they are if applied correctly, paying strict attention to the temperature of the chromate (60 - 70 ° C), pH, Concentration, and the agitation.

Regards,

John Tenison - Woods
- Victoria Australia

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