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Rough surface on plated parts

We have manufactured over 1500 components already and now we are getting a very pitted ugly finish. I suspect that there is a new batch of steel (44W hot rolled, 1/4") and it is the issue but I'm looking for a better explanation. I suspect the pickling process is removing something but not everything which leaves a multilayered surface after plating. You can even see some colour variation in the raw steel before plating.

Charlie Harland
engineer - Ottawa, ON, Canada
December 21, 2009

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First of two simultaneous responses -- December 23, 2009

Seasons Greetings Charlie!
I'm sure your company is familiar with pickling 44W steel. I'm also confident you have had good success in the past with your pre-clean process on that same grade of steel.
You could take some steel from the same lot that is suspect, have the lab personnel or platers make up new pre-clean solutions, pickling solution, and plate (this could be done on a much smaller scale of course) and run some controlled tests. I was always taught to isolate the problem by means of the elimination of potential process problems. If you can't duplicate the problem with the test lot, something went wrong with the run that produced the bad parts. Bad chemistry, improper temps, line worker screw-ups, etc. If the problem still exists after the controlled test run, and you know for a fact everything is in spec, then yes, the finger should be pointed at the new batch of steel. I hate to sound so elementary and fundamental but the whole approach works and solves problems. Good Luck to you.

Mark Baker
Fellow Plater - Syracuse, NY USA

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Second of two simultaneous responses --

Could you please provide further information, such as which plating process in use, final deposit?

Thanks.

Dominik Michalek
- Sydney, Australia
December 25, 2009