PWHT with several steels at the same time

[mariovalenti]

I need to do a PWHT to a pressure vessel manufactured with steel carbon (SA516 º70).
Inside it there is (welded) some thin pieces with SA240-316 steel.
Is there any problem to do this PWHT (at normal temeperatures for relieving post welding stresses)?.
Thank you in advance.
Mario

 

[metengr]

mariovalenti;
Can you come back with how the plate or sheet is attached to the vessel interior. Is the SA 240 316 ss for cladding or tray supports? The reason for my asking is that distortion can be a concern during exposure to PWHT temperature of 1100 deg F.

Regarding the 316 stainless steel itself, you will be in the range of exposure to sensitization since this is not a low carbon grade (316L). However, there is not much you can do about this because if you have already installed this material, PWHT is required to be performed for the CS as you mentioned.

 

[mariovalenti]

metengr;
the internal is a mesh of thin plates of SA240-316, into a carbon steel box (like in a scrubber). This box is welded to the shell.
The mesh is not a pressure part.
Thanks. Mario