Welding Procedure Qualification in accordance with AWS D11.2 –Guide for Welding Iron Castings.
Section:
C2.2.2 Base Metals
C2.2.2(1) Group. The various groups of cast irons are listed in Table C1 and are based on type of material (gray, ductile, malleable, etc.). Use of material not in the same group requires requalification.
(2) Carbon equivalent. The carbon equivalent of the base metal used in procedure qualification shall be determined by actual chemical analysis of the test plates and the following formula:
CE = C + 0.31 (Si) = 0.33 (P) + 0.45 (S)
-0.028 (Mn) + Mo + Cr
-0.02 (Ni) – 0.01 (Cu)
The procedure shall then be valid for use on all metals within the same group with a CE lower than the CE of the test plates or with a CE no more than 1.1 times the CE of the test plates. Base metals with CE’s greater than 1.1 times the CE of the test material require requalification.
My question; Table C1 list ASTM specifications for each group (A, B, C), if the ASTM number to be used in production is not listed in a group listed in Table C1, but the base metal CE is lower or is not, no more than 1.1 times the CE of the test plate used for Procedure Qualification, is requalification required.
Rick,
Currently I am also qualifying three procedures per AWS D11.2-89, and find some requirements difficult to understand. I think the answerer to your question is; any material not listed in Group A, B, and C requires a separate procedure qualification. The carbon equivalent statement applies to the base materials listed in each individual groups.
Jinx
JINX,
Your reply is the way I interpret it also. Ductile iron welding has come a long way since 1989. AWS D11.2-89 should be updated to clarify some of the requirements.
Thanks,
Rick
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