All welding variables procedure specification are provided in article IV. It is separated for each welding procedure application from table QW-252 through QW-256.
Base metal are assigned P number in QW-422 and base metal qualification in QW-424, main purpose of P-Number to reduce number of welding procedure qualification if material are the same weldability, chemical and mechanical.
Example: PQR qualified on ASTM A106-B to ASTM A234 WPB
- Base metal are in P-Number 1 and Gr-Number 1, see table QW-422.
- So, WPS shall qualify for the same base metal P-Number such ASTM A105, API 5L Gr. B or ASTM A36,…
If CNV requirement, the Gr-Number shall be essential variables. So, above WPS shall not be qualified for ASTM A105 or ASTM A516 Gr. 65 (Gr-Number. 2).
- This WPS does not qualify for ASTM A182 F316L (P-Number 8) because of different base metal P-Number.
Read more: Base metals selections for WPS (ASME IX).