Where the
world gathers for metal finishing
Q&As since 1989


-----

Trivalent Chromium Passivation

Dear Sir / Madame,
Do you have any information relating to Trivalent Chromium Passivation (Cr3) which is done after first Zinc plating the substrate. Typically substrates are Carbon Steel and Zinc itself.

This type of passivation is replacing the traditional Hexavalent Chromium (Cr6) which has been reported to have health risks associated to it. Typical platings such as BZP with Clear / Yellow / iridescent / Olive / Drab etc. Passivation.

I would like to know particularly what standards apply to the Zinc Plating that uses the Trivalent passivation.

Regards,

Steven Frank Wilkes
ERA Products Ltd. - Willenhall, West Midlands, ENGLAND
2006

This subject has been covered in great detail on this site and a search should uncover the information you need. Normally, I'd not recommend an article in a rival publication to Finishing but as the one I'm going to is UK based I may just get away with it. In the January 2006 issue of "Surface World" magazine at www.surfaceworldshow.com/publication-form there is an excellent article by Paul Wynn of Macdermid on this subject and another by Roger Lawson of Schloetter. Both companies, and I'm sure supporting advertisers on the site can steer you in the right direction and offer you all the advice you should require.

John Martin
- Wales
2006

Ed. note: Although excerpts from these pages were printed as a monthly column in Metal Finishing magazine in our early years, finishing.com is an independent website that has no relationship to any printed journal.
Update Feb. 2015: Elsevier closed down Metal Finishing magazine in Dec. 2013.