WELDING OF CR-MO STEEL P9 GRADE WITHOUT PWHT - USING 625 INCONEL FILLER METAL 1

[GabrieleB]

A supplier of Heat exchanger made in SA 387 Grade 9 steel to avoid the PWHT is going to use a filler metal ERNiCr-3 (alloy 625).
The welding process is made with 4 passes of GTAW (thickness qualified 9mm).

It is sufficient this process to avoid the PWHT that is usually mandatory required for Grade 9 materials (9%Cr-1Mo) P-NO 5B?

Waiting for a kind response.

 

[weldstan]

Ask the supplier to quote where it is permitted in ASME VIII Code or Code Case thereto. This technique was originally developed by EPRI for repairs to P91 boiler tubes.