Ah, my mistake...I had 2 thoughts going and thus started the message with one thought, but changed to the other without proof-reading...
Anyways, originally we were to complete an autogenous weld and my question would have been about any matallurgy concerns between 310 and 321 with-out filler.
Now the 2nd part of the question is, if we were to use a filler, would ER-347 or ER-310 be the more appropriate choice.
We are welding thermocouple sheilds (SS-310) to the external surface of SS-321 heater tubes (the 321 being chosen for it's internal contents, not the external heater environment).
Any insight to both scenario's (with or with-out filler) is greatly appreciated.
Thanks,
Joe W.