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QW-403 Base metals qualification

Most questions related to base metal and qualification.

  • Our procedure can cover for these material?
  • These base metal / thickness had qualified or not?
  • New QC inspector want to make a welding procedure specification?

So, l'd like to share tip how to prepare a welding procedure meet ASME Section IX.

All welding variables procedure specification are detailed in ASME IX article IV. It is separated for each welding procedure application from Table QW-252 through QW-256.

Main purpose of P number are listed in QW-422 to reduce number of welding procedure qualification if material are the same weldability, chemical and mechanical.

ASME Section IX book on your hand and must available for verification. 

A simply example: PQR has qualified on ASTM A106-B (P-No. 1).

The development WPS can qualify for ASMT A105, A234-WPB, A333 Gr. 6, EN 10025-2 S235JR.

But this WPS does not qualify for ASTM A182 F316L because of different base metal P-number, it was assigned P-No. 8.

Remmember an assigned P-Number for ASTM A106-B (P-No.1) and ASTM A312 TP316 (P-No.8) for detail thereafter explanation .

BASE METAL GROUPING in QW-420.

  • Steel and steel alloys: P-No. 1 through P-No. 15E.
  • Aluminium and aluminium-base alloys:  P-No. 21 through P-No. 26.
  • Nickle and nickle-base alloys:  P-No. 31 through P-No. 35.

And other material, you may find more in QW-420 and Table QW-422.

How to verify?

Please look at QW-424 - Base Metal Used For Procedure Qualification and read carefully.

In case of material do not list in table QW-422, so it consider to be unassigned metal.

  • Assigned metal number: listed in table QW-422
  • Unassigned metal number: not shown in table QW-422.

Ok, It is hope to clear your concern.

Next, we need to know about base metal used for procedure qualification coupon (LIFT COLUMN)  and base metal qualification (RIGHT COLUMN)  as detailed in table QW-424.1.

Follow and understanding each phrase of left and right columns.

1. The same an assigned P-Number

Left column: One metal from a P-number to any metal from the same P-number.

Right column: Any metals assigned that P-Number.

Ex. PQR qualified for ASTM A106-B to ASTM A106B (P-No.1), the welding procedure shall qualify for ASTM A105N/ A234-WPB, A516 Gr. 60 to ASTM A105/ EN 10025-2 S235JR of any the same P-number , vice versa.

This PQR shall not qualify for ASTM A106-B (P-No. 1) to ASTM A312 TP316 (P-No. 8).

2. The different an assigned P-Number

Left column: One metal from a P-number to any metal from any other P-number.

Right column: Any metals assigned the first P-Number to any metal assigned the second P-number.

Ex. PQR qualified for ASTM A106-B (P-No.1) to ASTM A312 TP316 (P-No.8), the welding procedure shall ONLY qualify for P-No.1 to P-No.8 and vice versa.

This PQR shall not qualify for P-No. 8 to P-No.8.

3. The unassigned P-Number to any P-Number

Ex. PQR qualified for API 5L Gr. B (P-No.1) to AISI Gr. 4130 (Unassigned P-Number), the welding procedure shall ONLY qualify for P-No.1 to AISI Gr. 4130 and vice versa.

This PQR shall not qualify for P-No. 1 to AISI Gr. 4137, 4140, 4145Hmod due to different the unassigned metal.

4. The unassigned P-Number to other unassigned P-Number

Ex. PQR qualified for  AISI Gr. 4140 (Unassigned P-Number) to AISI Gr. 4130 (Unassigned P-Number), the welding procedure shall ONLY qualify for  AISI Gr. 4140 to AISI Gr. 4130 and vice versa.

This PQR shall not qualify for  AISI Gr. 4140 to AISI Gr. 4140 or 4145, 4137 due to different the second unassigned metal.

Ok, above 4 examples hope to clear your question and knowledge about ASME section IX for base metal qualifcation.

These explanations just cleared for you about P-number, in case of impact test required in PQR. Please must note the change of grouping number, you may learn more the article "Impact test for welding procedure qualification"

For other things, you may find out and clear your questions/its answer in ASME Interpretation.

Nguyen Duy Bien
 

Enjoy learning and researching, reading book. Knowledge welding inspection painting inspection.

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Thanks