Welding comsumable for TP22 to UNS 44600 at 610 deg, C 1

[SJmetallurgist]

Hello

I am reviewing a WPS where my supplier has to weld A213 T22 tube to a thermocouple pad of material UNS44600. The operating temperature is max 610 deg. C. They are using ENiCr-3, which is classified to be used upto 480 deg. C. My earlier preference was to suggest them the use of ENiCrMo-3, however, even this consumable us usable upto 540 deg. C. Can any body please suggest me the appropriate consumable whioch could be used for this welding? Please note that the thickness of T22 tube (3.08mm) does not require any PWHT as per code, so this welding will be done without PWHT. Ofcourse other normal parameters of preheat maintenance and post heatin (dehydrogenation will still be applied to the joint due to T22 tube material in use.

Please suggest. Thanks.

Regards
Shashank

 

[metengr]

Use ENiCrFe-3 for this DMW.

 

[SJmetallurgist]

But the consumable is simply not classified with usability at the temperature I am looking for, 610 deg. C. your comments on this aspect pls.

 

[metengr]

The useability service temperature for this weld metal is up to 732 deg C based on studies done by Oak Ridge National Lab on the breeder reactor program. In fact, we have many dissimilar metal welds between T22 and austenitic stainless steel made with E and ERNiCr-3 filler metals. Actually, the limiting condition I see is use of T22 material at 610 deg C rather than Inconel filler metal.