Seal Weld Tubesheet 1

[leon_har_dt]

Hi all
hope you are doing ok
Questions: can i do a seal weld between 904L N08904(tube) and 316L(tubesheet) with gtaw autogenous welding? i read that 904l could lose a little of corrosion resistance, but in this case, as only seal weld the tube expansion is in charge to resist forces.
Anyone had experience with this kind of welding? any suggestions?

Thanks

L.

 

[EdStainless]

Sure you can weld them, they are both austenitic SS alloys.
Picking a filler will be tricky, don't use 904L but do use something with higher alloy content than 316L.
Your weld practice will also need to be very good as 904L can be hot crack sensitive.

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P.E. Metallurgy, consulting work welcomed

 

[leon_har_dt]

Thanks for you answer!
i always see you replying on these topics and always good responses.

I will do some mockup test(I have to test rolling expansion too) so I will take into account the hot crack phenomenon.

L.

 

[leon_har_dt]

I forgot, about the filler, i dont have enough ligament dimension ( or tube separation) to do a manual gtaw weld with a filler. Thats why i just want to do autogenous weld. its more common in the shop to do.
I would do some test with a filler, i think i would be worth it.

 

[EdStainless]

Before you try autogenous welds check the ferrite number.
The 904L often has a negative FN, and you would really like some ferrite to form.
You may just need to have the tubes project a little farther than normal so that you melt more 316 into the weld.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed