Acceptable Welding Methods (section VIII) 3

[PipingEquipment]

In general what welding types are acceptable for ASME section VIII?
I need to join some aluminum and am considering a "new" type of welding; friction stir welding. I have searched section VIII and the web and cannot find whether this is kosher with the code.

Can some one help?

 

[metengr]

PipingEquipment;
Get your copy of ASME B&PV Code, Section VIII, Div 1 and review Part UW-9 and specifically, UW-27 (b). Inertia and continuous drive friction welding processes are permitted.

 

[PipingEquipment]

THANK YOU!

 

[GRoberts]

Inertia and continuous drive friction welding are different weld processes than friction stir welding.

 

[PipingEquipment]

Yeah, I just found this out. I was thinking they were calling continuous drive friction, friction stir welding...

What do you think it would take to add FSW to that list? There are some pretty rare/extreme welding types on that list, including explosive welding, one would think FSW would be acceptable as well.

 

[metengr]

It would be called an ASME B&PV Code Case, and you would need to follow the rules in Section IX for a Code Case submittal for FSW.

 

[PipingEquipment]

Ok that's what I'll do then.
I need to compile some research info and get all my ducks in a row so I can present a strong case.

Any recommendations or information on this code case submission process would be greatly appreciated.

 

[metengr]

Well, (as a standards committee member) I would suggest you provide detailed background as to the welding process, practical use of this proposed welding process on a mock-up of a pressure retaining item simulating weld joint configuration, etc., and of course testing methodology, using Section IX as a guide for procedure qualification testing. Hardness testing and metallographic evaluations will be necessary for this code case submittal.

Once the FSW procedure can be qualified you need to focus on mechanical testing of FSW samples comparing mechanical property test results with inertia and continuous drive friction weld results. I would perform RT and elevated temperature tensile testing for materials of consideration.

Still interested?

 

[PipingEquipment]

Very much interested. Thank you for the info.

In my previous job I worked as a researcher at a laboratory that focused on friction stir welding. I know it is a mechanically sound process given the correct range of parameters.
I have access to the right equipment to make this happen. So, it may be a ways down the road (a few years?), but expect to hear more about this at some point.

Any other advice is greatly appreciated.

 

[SJones]

Perhaps the Welding Journal article in April 2008, pages 40-44 regarding aluminium pressure vessel welding at Lawrence Livermore will be of assistance?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[PipingEquipment]

Undoubtedly Helpful, Thank you!

https://e-reports-ext.llnl.gov/pdf/348540.pdf

 

[GRoberts]

I believe that ASME Section IX is already working on FSW rules to add.

 

[metengr]

If Section IX is revising Code rules to endorse FSW this can take time, and I have seen nothing submitted for vote as of yet. A code case submittal can be handled in one meeting cycle with the appropriate documentation. Usually, code cases move quicker because of a demonstrated need. Once the code case is issued, revision to code rules follows after demonstrated experience.

Second, just because Section IX addresses a new welding process doe not mean that Section VIII will permit it. This is why a Code Case would be more efficient and allow FSW to be endorsed by IX and VIII Standards committees.

 

[PipingEquipment]

Groberts, can you please elaborate on the specifics of what you heard?

 

[GRoberts]

I was at a seminar given by a Section IX committee member. It was listed among the changes being considered for Section IX. Some other ones were elimination of S numbers, and addressing hybrid welding processes, such as laser-GMAW. I wasn't sure of the time frame, but I mostly mentioned it because if someone is considering applying for a code case, it would make sense to make use of any work Section IX has already done on the subject instead of repeating it.

 

[metengr]

I did some digging around on ASME C&S connect for BPV IX committee Agenda (August, 2009) activities regarding this item, and from what I could gather there was a code case for this process. The Code Case is 2593. The item number is 08-265, and it looks like BPV IX committee is going to add a new QW-266 listing essential welding variables for the FSW process at some point in the future.

As I said and as mentioned in the item description it will still be up to other code book sections to adopt this particular welding process. However, just the fact that they have an approved Code Case is a huge start. The Code Case mentioned above was generated for FSW of 5052 aluminum alloy expansion joint bellows. Although limited in scope it is a start.

You would still need to generate a new Code Case specific to fabrication of vessel welds.

 

[PipingEquipment]

Great thank you.

http://cstools.asme.org/csconnect/PDF/CodeCases/1868.pdf