Ferritic contamination of titanium
Ferritic contamination of titanium
(OP)
In some specifications, we need to perform a contamination test (ferroxyl test) on titanium stuff before heat treatment.
I would precisely like to know what happens when you throw into a furnace for a stress reliving heat treatment a part of ferritic contaminated titanium.
Is it possible after the heat treatment to detect some contamination if testing or handling was improper before the HT? If yes, by which methods?
I would precisely like to know what happens when you throw into a furnace for a stress reliving heat treatment a part of ferritic contaminated titanium.
Is it possible after the heat treatment to detect some contamination if testing or handling was improper before the HT? If yes, by which methods?





RE: Ferritic contamination of titanium
Section 7 (Inspection after Cleaning) gives a couple of tests for detection of iron contamination. We have used the Ferroxyl Test very succesfully on titanium alloys. Application of the solution was carried out with a spray bottle. Removing surface iron contamination can either be done by brushing off, washing off or ultimately by grinding out and welding up the hole (if allowed).
We heven't needed to do any stress relief, so I can't tell you what might occur with the test. Try deliberatly contaminating a piece and testing after H/T, and let us know what you find.
RE: Ferritic contamination of titanium
My concern is that I heard that once heated, the contaminant parts migrate into the titanium and cannot be detected any more, while hampering the corrosion resistance of the titanium. This may be the reason why some engineering specs (AMOCO, KVAERNER, etc..) are asking the cleaning to be performed before any HT. I would like to find somebody with some feedback about this.
RE: Ferritic contamination of titanium
RE: Ferritic contamination of titanium
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Plymouth Tube
RE: Ferritic contamination of titanium
It is true that we may see Fe contamination when pickling the parts, however, this is not an option for us because we are manufacturing titanium bonded steel plates and the pickling solution will attack the backer steel.
I also read in a paper that iron contamination could favor hydrogen absorption of titanium, which also hampers corrosion resitance. Anybody to comment?