6061 aluminum and NAVSEA Tech Pub S9074-AR-GIB-010/278

By kcd616

Date 06-12-2015 23:35

Carl,
let this go to Henry
my very good friend
best there is
and knows navy code
better than anyone
sincerely,
Kent

By 803056

Date 06-13-2015 13:52

The fabrication standard NAVSEA TP278 refers to NAVSEA TP248 for the qualification of the WPS and the welder. One clause states the minimum tensile strength of the welded joint must produce the same mechanical properties as the base metal. Unfortunately, the as wrought tensile strength of the 6061-T6 is 42 ksi while the as welded tensile strength of 6061 is only 24 ksi if everything is done by the book. As such, 6061-T6 is not a listed base metal, thus it has no S number assignment.

Any drawing that specifies 6061-T6 base metal must have specific approval from NAVSEA or SupShips depending on the type of vessel involved and the specific application.

Best regards - Al

By Milton Gravitt (***)

Date 06-13-2015 15:22

Good info Al.
M.G.

By ssbn727 (*****)

Date 06-19-2015 06:03

Thanks for those kind words but truth be told, I have been away from EB for too long to know what's the latest going on @ Quonset PT. or Groton, CT these days so I have to defer to the rest of the fine folks in here familiar with NAVSEA codes and any or all of the changes made. :grin:

Respectfully,
Henry

By Kix

Date 06-15-2015 11:30

Is this your first time working to TP 278 and 248? If so, you might also want to parallel efforts to meet the requirements of 5.2.3 and 5.2.3.1 in TP 248 while you're working on the material approval.

Regards,

Kix

By PJENGINEER Date 06-15-2015 13:28

Thank you all for your input. Kix, this is not our first time working with the TP 278 and TP 248 documents. We had just gone through the loooong arduous one year process of getting our weld procedures approved by General Dynamics Electric Boat and brother was that a learning experience!! We did in fact go through the exercise of getting an approved training program set up and provided the training to meet the requirements of 5.2.3 and 5.2.3.1.

I apologize ahead of time for the long post....
I am a manufacturing engineer by trade with a background in welding but by no means do I consider myself a weld engineer. The component in question is for a naval amphibious watercraft. It is a NAVSEA drawing and a new design which started out referencing MIL-STD-1689 and at some point was changed to the NAVSEA TP 248. What I failed to mention in the initial post is that the 6061-T6 weldment does go through a post weld heat treatment process to bring it back to the T6 condition but I am still unsure how (or if we can) qualify our procedure top TP 248.

As I stated earlier there is a flag note in the tables for the "Grouping of base materials" in the TP 248 document which states:
1/ If material of similar chemistry and mechanical properties is not listed under an "S" group, it may be considered as part of a group upon approval.

Based on this flag note, our assumption would be to produce a PQR following the guidelines of a similar "S" number (in this case S-25) but specify the alloy and filler metal that is actually being used (6061-T6/ER4043). The coupon(s) welded under the PQR would have to be heat treated and brought back to the T6 condition to mimic the production parts prior to all visual, radiography, NDT and destructive testing that is required. Once this has been accomplished, we would then submit the WPS/PQR and supporting documents to our customer for final approval. It ultimately would be there responsibility to forward to NAVSEA/SupShips for final approval.

Does this sound like a reasonable approach or should we just be pushing them toward AWS D01.2 for structural welding of aluminum.
Thanks for your time!!

Carl

By Kix

Date 06-17-2015 12:10

Carl,

Before you qualify your PQR using an unlisted base material, it has been my experience to submit a VIR requesting approval for 6061-T6 to fall under S-25 material grouping before potentially wasting time and money. Looks like you should be good for your filler material because it is listed both commercially and with a Mil-spec. Are you dealing with EB on this project? I ask because they have a intricate set of rules for procedure submittals now. That goes for NDT procedure approvals as well.

Regards,

Kix

By PJENGINEER Date 06-17-2015 19:13

I just submitted our steps for moving forward using the S-25 grouping to our customer and they gave us the approval to proceed. We just spent a year getting three procedures approved by EB and the buyer informed us that this was one of the quickest turnarounds he has seen. We are all too familiar with the VIR/VPAR process. Believe you me, if EB was the customer, I wouldn't even be attempting this. By the way, if you ever need a crash course on the intricacies of TP 278 and 248, just drive through it one time EB... :eek:

Those guys are on their game!!

Thanks again for all your help! What a great forum!!

Carl

By Kix

Date 06-18-2015 19:19

Carl,

EB is one of our customers. I know your pain brother! We have contracts on all of the submarines in one form or another. Glad to hear you're off an running. Nothing worse then hurry up and wait. :wink:

I went to EB's welding conference last year and they made it a point to let everyone know that there has only been one welding procedure ever to make it through without any comments. It was recent and was utilizing the new NAVWELD software developed by Weld QC for Newport News and EB.

Good luck,

Kix