Ferrite Number Testing for Nickel alloys
Ferrite Number Testing for Nickel alloys
(OP)
One of our client specification says Ferrite number testing for Nickel alloys.In my knowledge Ferrite number testing is applicable for Stainless steel and Duplex stainless steel welding.
I feel the Nickel alloys (Alloy UNS N06625,N08825 &N08028 -Incoloy& Inconel)welding ferrite number testing is not applicable.
Any expert can advise me on this.
I feel the Nickel alloys (Alloy UNS N06625,N08825 &N08028 -Incoloy& Inconel)welding ferrite number testing is not applicable.
Any expert can advise me on this.





RE: Ferrite Number Testing for Nickel alloys
The client may have other reasons for measuring delta ferrite, nickel alloys can be carburized and a ferrite tester may indicate the amount of magnetism.
RE: Ferrite Number Testing for Nickel alloys
It can also help identify if the wrong filler has been used.
You would be trying to measure small levels, say below 5%.
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Plymouth Tube
RE: Ferrite Number Testing for Nickel alloys
We've been trying to put together a weld repair procedure for duplex for a while. Well, not trying, but just suffering without one.
A metallurgist consultant recommended that above other criteria, we must ensure that we have no more than 50% ferrite in the HAZ. (We have sealing surfaces exposed to sea water in these areas.) We've found through trial and error that we can't do it for some reason.
Can anyone provide some clues for me to bring up with manufacturing?
RE: Ferrite Number Testing for Nickel alloys
What is the filler metal composition you are using for weld repair of duplex stainless steel? Normally, for weld metal microstructure for duplex stainless steel you want to achieve a 50/50 balance with ferrite and austenite.
RE: Ferrite Number Testing for Nickel alloys
I've been told that we've sought out material that is 40 or 45% ferrite to start, so the ferrite increase in the HAZ may still be at or below 50% but they've been unsuccessful up till now.
My application in this case is weld repair of completed parts, so full solution anneal is not acceptable as the parts would deform in the furnace under their own weight. We have get a solution to weld without PWHT. If we do it right, we'll keep the sigma problem at bay and will be able to move ahead. Possible with the right tuning?
RE: Ferrite Number Testing for Nickel alloys
If you are in the range of 45 to 60% ferrite after welding duplex stainless steel, this is considered typical and should be acceptable.
RE: Ferrite Number Testing for Nickel alloys
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Plymouth Tube