Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

TFS(tin-free steel)continuous electroplating

Thread starter fredman
Start date Aug 22, 2002

Status: Not open for further replies.

Aug 22, 2002

fredman

Chemical

I am currently involved in commissioning of a 2-step hexavalent chrome continuous electroplating proccess,which uses CrO3 as a source of chrome,NaF as the catalyst, and in the second step NaOH for pH control to stop re-dissolution of plated metal oxides.Anodes are Pb,5%Sn.What I would like to know is some more specifics(on the atomic level) of the structure of the chrome, and how the catalyst works.Is the catalyst used just to break the bonds on the CrO3?What is the structure of the chrome,and how does is change by electrolysing?