A poison pad (SS) is deposited on a low alloy steel material, after PWHT,this pad is welded to another piece of SS. what kind of welding procedure should follow for the poison pad welding per ASME Code? seems to me, it is not buttering, not overlay. Do we need a WPS per ASME IX for this welding...
If there is water backing in the real application for an overlay work, do I need to consider the water backing when I qualify the welding procedure on my PQR coupon?
Thanks