Removing TCC coating from INC625 substrate

[mightyatom]

Hi Team,
This is my first posting and really need some advice.

We have applied an Inconel 625 ball and seat set with HVOF coating with Praxair 1350VM (WC-10%Co-4% Cr). The two suppliers we currently use are in the UK and in Italy.

Due to a design modification, we need to remove the TCC coating from 2 metal seats, which we thought would not be an issue as we have never experienced any problems before.
However, the normal chemical removal process used by two of our suppliers in the UK has a severe attack on the Inconel 625 base material, pitting it badly and rendering it un-usable.

The metal seat ring is a good size to work on and having a 12" dia contact area.

Is there a safe way of chemically removing TCC from inconel 625 without pitting the base material or will I have to resort to mechanical means.
If so, does any body have any recommendations on a professional that could look at my problem.

Look forward to help on this matter.

[Gordon]

Hi Mightyatom

to the Surface Engineering Forum.

Do you know what chemical method they used?

This link on the old message board may be relevant: messages/134.html