Slugging

By TimGary (****)

Date 04-10-2015 15:03

Dumb question for the day...

Ok, so everyone with even a little bit of weld joint design knowledge knows that "Slugging" ( aka - stuffing too large joint gaps with material to fill the gap and welding over it) is bad.
A3.0 defines slugging as "Unauthorized".
I'm having trouble finding just where in D1.1 that this is defined as unauthorized, or prohibited.
Can anyone point me in the right direction?

Tim

By ctacker (****)

Date 04-10-2015 15:18

Look at clause 5.22.1.1 (2010).
Carl

By TimGary (****)

Date 04-10-2015 15:50

Thanks for the reply, but this does not work.
See 2.11 for the definition of "Filler Plates".

Tim

By 803056

Date 04-10-2015 15:55 Edited 04-10-2015 16:02

There are a lot of bad welding practices that are not addressed by welding codes. The use of slugs is just one that is not specifically addressed by AWS. However, it does have a restriction that applies to spacers (refer to clause 5.2.2). In a nutshell, spacers have to be composed of the same material as the base metals being joined.

I have a question with this requirement, all the prequalified joint details that include the use of a spacer requires the spacer to be removed before welding the second side. Yet, a backing can be any prequalified base metal if the WPS is prequalified and in many cases the backing is left in place. This seems to be inconsistent considering the spacer is completely removed, thus should contribute little to the diluted weld metal chemistry. Whereas the backing, left in place, may alter the weld deposit chemistry. I resolve the conflict by assuming the amount of dilution is minimal and the chemistry of any base metal listed in Table 3.1 will do little to alter the diluted chemistry of the root bead. Still, I wonder aloud if this isn't just slightly delusional.

With regards to filler plates, any material that is part of the welded joint must be prequalified if the WPS is prequalified (see clause 3.3). If all the conditions of prequalification are not met, the WPS must be qualified by testing per clause 4.

Best regards - Al

By TimGary (****)

Date 04-10-2015 17:29

Thanks for the respone Al. I greatly appreciate your insight.

I hate to put you on the spot here, but I'm hoping that you can prove to me that the following is incorrect:

1. There is no prohibition to Slugging in D1.1 for non-prequalified joints.
2. Slugging is acceptable to D1.1 as long as it's qualified through the PQR process.

Please say it ain't so!

Tim

By 803056

Date 04-10-2015 18:55

Back to my initial response as my starting point; either the WPS is prequalified and meets all the conditions of prequalification, including the prequalification of all materials within the joint, or the WPS must be qualified by testing.

Assuming it is recognized that one or more of the components in the welded assembly, i.e., the joint, are not prequalified, qualification by testing is required. For materials not listed I Table 3.1 or 4.9, see Table 4.8, last line, the WPS is only qualified for those materials listed on the PQR. That being the case, one would have to know the pedigree of the materials used, including the material that was used as a spacer (slugging material in your case) to comply with Table 4.8.

Let's not forget that the materials used for slugging are defined as unknown or unauthorized materials. That would exclude them from use when welding the test assembly.

Al

By TimGary (****)

Date 04-10-2015 19:29

Ok thanks Al.

Looks like I'm going to have to eat some crow.
Man, I hate the taste of that stuff...

Tim