Welding: Using 304L vs 304L VIM/VAR

[DJI66]

Hi all, new here. We have a question regarding using 304L in a repair ( a small flange washer) to 26-6-9 ( Nitronic 40)We have an old call out for using 304L VIM/VAR, is there any appreciable difference?

 

[EdStainless]

Nit 40 is 21-6-9.
If the 21-6-9 is aerospace then it is ESR at least.
My guess is to try and keep everything as clean as possible.

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P.E. Metallurgy, consulting work welcomed

 

[MagMike]

DJI66: Did you intend this for the Magnetics Engineering forum? This might be a better question for the Welding forum:

https://www.eng-tips.com/threadminder.cfm?pid=725

 

[MagBen]

yes, there is appreciable difference. VIM/VAR or VIM/ESR 304 is cleaner than regularly melted 304. i had customers ordered both VIM/VAR and VIM/ESR 304 for medical and watch applications asking for least inclusions to control polish process (watch) and implant (medical).

Interestingly, VIM/ESR is a bit cleaner than VIM/VAR, although the latter is double vacuum melt, while ESR is not. it is a bit against intuition.

 

[EdStainless]

We used 21-6-9 that was AOD/ESR and it is cleaner than most Vim/Var.
It is the mechanical filtration effect of the ESR process that does it.
These alloys can be difficult to weld since the weld pool has lower fluidity.
No S and O2 will do that.
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P.E. Metallurgy, consulting work welcomed