D1.2 2003 and PWHT/stress relief

Date 02-04-2009 16:49

I've got an application where we're going to need to stress relieve a 5086-H116 structure after welding (I think it's 400F for 4 hours but I could be wrong). The PQR was not done with the stress relieve, and since 5086 isn't heat treatable, I think we're ok to fabricate. But here's my question/confusion: it seems odd that PWHT isn't an essential variable in D1.2 - unless I'm missing something. Can someone shed some light on this for me?

By Ke1thk

Date 02-05-2009 16:18

I don't see it as an essential variable in Table 3.1 of D1.2, 2003 either, but, PWHT is listed on the PQR form in the back of the code. They have four lines of information to fill out. Page 142.

Keith

By GRoberts (***)

Date 02-05-2009 23:32

Be careful when heating 5000 series aluminum (that has above a certain percent Mg that I can't remember off the top of my head, but I know 5086 is high Mg) for PWHT. D1.2 has some specifications on that- time at temperature limits. The problem is that it will sensitize the aluminum to stress corrosion cracking. What sort of environment is the weldment going to be used in? Unless you can guarantee it will never see an electrolyte, such as water, condensation, etc., you may want to re-consider PWHT.