Cladded Tubesheet to tube weld material clarification Required SA-266 Gr. 2/4N , SB-111, UNS (C7060

[staticmh]

Hi All,

Appreciate to have expert opinion from welding and material perspective.

Case details: Heat exchanger tube to tubesheet weld Joint

Tube sheet base material is SA-266 Gr. 2/4N
Which have explosion bonded Cladded face (10mm) with - CrNi 90/10.
Tube material = SB-111, UNS (C70600) (CuNi 9010), FINS-ALUMINIUM

Questions:

1- What will be the weld material for strength welding in between tube sheet cladded face material (CrNi 90/10) to tube (SB-111 , UNS C70600 (CuNi 9010)).

2- What will be impact of using silver brazing, need suggestion to evaluate it and to avoid any expected repair/failure after operation of HEX.

3- What will be the correct weld filler material ?


Thanks in advance.

 

[CuMo]

What is the bundle?
Fixed tubesheets, floating head, U-bundle?

Is it mandatory that you use strength welding?

Could you not just use double grooved holes and expand only in case the tubesheets aren't fixed?

 

[staticmh]

@CuMo

Its floating head.

Yes mandatary to do strength welding.

My query is pertained to welding material between tube sheet cladded face material (CrNi 90/10) to tube (SB-111 , UNS C70600 (CuNi 9010)).

 

[EdStainless]

When welding these you had better not be into the base metal at all.
This needs to be purely a CuNi-to-CuNi weld.
There are CuNi weld fillers.
I doubt that you could get away with braze as you would need to validate strength, fatigue, and corrosion resistance.

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