Dear Muhammed,
You are missing a key provision in ASME Section
IX. Look at QW-423, Alternate Base Materials For Welder
Qualification. QW-423.1 states: "Base metal used for
welder qualification may be substituted for the metal specified in the WPS in
accordance with the following table. When a base metal shown int the left
column is used for welder qualification, the welder is qualified to weld all
combinations of base metals shown in the right column, including unassigned
metals of similar chemical compositon to these metals." Of primary
interest is the first entry in the table:
Base Metals for
weld qualification: P/S No. 1 through 11, P/S No. 34 and P/S No. 41
through 49 (any one of these base
metals qualifies for all base
metals in the following)
Qualified Production Base Metals: P/S No. 1 through
11, P/S No. 34 and P/S No. 41 through 49
The welder or welding operator will be limited for the
other process essential variables - see QW-352 through QW-357 (or QW-416
summary) for weldors and QW361.1 or QW-361.2 for welding
operators.
It is my understanding that ASME is concerned with the
weldor being able to handle the assigned weld metal and deposit sound
weld metal. Theoretically, the WPS has already established that the
total weldment (base metal, HAZ, and weld metal) will be sound,
meet Code requirements, and have adequate metallurgical
properties.
A customer can, of course, additionally restrict
qualification in contract documents but then should also expect to pay a
premium for the additional work that must be performed.
Hope this clarifies this issue.
John