Presented in Partnership with:

Ask the Expert Question-and-Answer Archive
(Hard Chrome Plating)

by Randy Taylor, Advanced Tooling Corporation.
May, 2006

Spots on Nickel/Chrome-Plated Parts

Q. After brazing a powdered metal part onto an alloy steel shaft, the entire part is nickel chrome plated and on a percentage of the parts, raised "hive like" spots appear along the length of the square shaft, usually only on two of the four faces. Any ideas on what would cause this?

A. Possibly flux residue from the brazing operation is leaching out or is otherwise present on the substrate. If so, delamination, as you described, is possible. To fix this problem, you may need to change your pre-plate methods. Here are a couple of suggestions to try:

Pre-clean using fluoroboric acid dip (40%:60% acid::water). Perform a 1.0 minute warm up in the chrome tank. Step voltage/amperage to desired level.

As an alternative, after fluoroboric acid pre-clean, go directly into chrome bath with "live current" at 2.0 to 2.4 volts and then step the voltage/amperage to desired level.




The information contained in this site is provided for your review and convenience. It is not intended to provide legal advice with respect to any federal, state, or local regulation.
You should consult with legal counsel and appropriate authorities before interpreting any regulations or undertaking any specific course of action.

Please note that many of the regulatory discussions on STERC refer to federal regulations. In many cases, states or local governments have promulgated relevant rules and standards
that are different and/or more stringent than the federal regulations. Therefore, to assure full compliance, you should investigate and comply with all applicable federal, state and local regulations.