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I'm trying to help a fabricator who was contacted by the AISC to perform some welding of various plate configurations and joints with primarily PJP and fillets that will be used in the AISC's testing. So I'm looking at writing WPSs to cover all of this. If I'm thinking about this correctly, we will need to qualify these procedures due to the filler (E80 and E100) is overmatched and is not listed in Table 3.2 as a prequalified filler for A572 gr50.
Questions to follow once I read more.
Looks like we'll need to verify the consumables.
Consumables verification test per 188.8.131.52 (1)
Configured per Figure 4.16, Cut from coupon per Figure 4.18.
There is no provision for over matched filler metal in Table 2.3 or clause 3.3. The use of over matched filler metal would require the Engineer's approval since Table 2.3 does not include provisions for over matched filler metal.
There are instances where the designer assumes the weld size can be reduced by using a higher strength filler metal. In the case of over matched filler metal, the base metal is the weak link. As per Table 2.3, the limiting factor would become the allowable unit stress permitted for the base metal rather than the filler metal. Consider the use of E7018 when welding ASTM A36, the weld size is a function of the yield strength of the base metal when a full strength weld is required, i.e. the strength of the weld must develop the full strength of the base metal in both tension and shear. The weak link is the allowable unit stress of the base metal in tension and shear.
The Owner's Engineer would have to agree to using over matched filler metal whether the contractor qualifies the WPS or not.
I would expect that the testing regiment would include a transverse reduced section tensile test to demonstrate the weld and the base metal provide the requisite strength. The "all weld metal reduced section tensile test" doesn't accomplish that. It does demonstrate the filler metal produces tensile properties at least equal to those of the base metal. It doesn't demonstrate the deposited weld produces mechanical properties that match the properties at least equal to those of the base metal in the region of the weld interface. The commentary offers no help in this situation.
However, I don't see any provisions that would circumvent the need to perform the testing required by clause 4.12.3. I believe you would still be required to qualify the WPS by testing that included the NDE, bend tests and transverse reduced section tensile tests. Seems like that could be accomplished if the length of the test plate was sufficient to included the added test specimens.
Maybe Lawrence with chime in on this one.
Thank you Al for chiming in.....
The engineer in this case is unknown. This is a case study for the AISC. They want the fabricator to weld up a whole host of joints and then ship them all to them for testing to be carried out on the welded samples.
If these are simply test samples, i.e. they are not intended for production, why qualify the WPS? The most likely purpose of the welded samples is for testing. Maybe a phone call to the customer, i.e. AISC, would clarify their needs.
I'm with Al on this sort of.
I've been doing some similar stuff with MBMA and Virginia Tech Maybe it's even related.
I think all of the testing is a great idea... But I would have thought the team at AISC would have lined out exactly what they wanted from you in that regard, especially if this is sort of uncharted territory, with the assumption that they are going to be evaluating the strength gained in PJP connections via overmatching. At least that's what it smells like.
While your at it (throwing questions back upstream to AISC) You might want to ask about UT procedures developed in accordance with Annex Q for those PJP end connections... When they test those to failure they are going to wish they had them :)
I hate to throw them under the bus... But Robert Shaw and Mike Gase are both AISC guys that are probably involved at least in some small way here via their presence on the Chapter N Committee, and well, Mr. Shaw has his hands in most of this stuff because he is really smart. If you get pushback on your request for more guidance let me know and I will put you in contact with one or both of them...
I hope the committee that will be doing the testing doesn't include the same people that decided welding over residual water, oil, grease, etc. is perfectly fine. I can't wait to see the new 2020 edition of the Farm Code.
It would be nice to talk about the code with a straight face once again.
Wait a minute. Maybe the samples you fellas are making should include contaminated surfaces.
The boss is going to be so pleased to hear we can weld in the rain now
Only if its residual rain.
I emailed the fabricator after Al's suggestion that the welding may not even need to have a qualified procedure. I told them we could write a WPS just to keep the welder on task and monitor the parameters and whatnot so the AISC would have that information to go along with their samples.
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