WPS for Aluminum 6061 T6 (Tensile Test) 1

[Danieeel]

Hi everybody, i recently joined in this site because i was in need for some info related to a qualification (WPS) for Aluminum. I have been looking for some threads related to this and i found this, which is exactly the same doubt i have at this moment.

The thread is thread292-388690 , and i copied literally from the original post:

Hi all, I have question regarding minimum tensile strength requirement of a tensile test specimen for welding procedure qualification according to ASME Section IX BPVC. The base material i am using is aluminum 6061 T6. For this material the minimum tensile strength requirement as specified by the section IX is 24 Ksi, but, infact the strength of base material is higher( 43Ksi) than that of as specified. The same trend i observe in other grades of aluminium.

I am aware of the strength loss due to welding of aluminium in its heat treated condition because of partial annealing/overaging. Strength of annealed base material 6061 is 18 Ksi.I also know that after welding in heat treated condition,there must be complete reheat treatment to regain the lost strength in fusion zone and HAZ. But, then why ASME states that welding procedure will be qualified if the specimen ruptures at or above the 24 Ksi strength.?
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My question is the same, why does the code ask for the 24 ksi tensile stregth? if my base metal certificate says that it UTS is 45 ksi? The answer is because of the properties lost during the ''annealing'' treatment due to welding? or is it because of the filler metal strength? i used ER 4043 and 5356.

I checked the code acceptance criteria for tensile test and i found this but i do not know if it is applicable for this specific case:
QW 153.1 In order to pass the tension test, the specimen shall have a TS that is not less than
(C) the minimum specified tensile strength of the weld metal when the applicable section provides for the use of weld metal having lower room temperature strength than the base metal.

Thanks a lot in advance and i apologize for my english.

Best Regards
Daniel

 

[CWEng]

Have you checked ASME Section II Part D to see what the allowable stresses are? I would imagine it is related, which is also probably related to what tensile strengths of welds are achievable in the real world. Just my guess at this point.