Wednesday, February 3, 2016

What's With Weave Width? (Woah!)

Good morning Paul,
I have a question for you.
When welding (1/8") E7018 welding rods, what's the maximum width for stringers and for weaving?  I've heard different answers but can't find anything in the D1.1 Structural Code.
Thanks and have a good day!
Ivan A.

Ivan,
For the process you mentioned, SMAW (E7018), you will not find many restrictions on weave/oscillation width. Table 3.6 in Clause 3 - "Prequalification of WPS's" limits the maximum size of single pass fillet welds to somewhere between 5/16" and 1/2" depending on the position.  That would be a limitation on weave width.  Table 4.6 in Clause 4 - "Qualification" would also limit weave/oscillation width in Charpy V-Notch Testing (CVN) applications by limiting heat input and weld metal volume (see: Electrical Characteristics 9).  Travel Speed plays a key role in both those calculations and weave width has a direct impact on travel speed (the wider the weave, the slower the weld progression, or travel).
With other processes (GMAW, FCAW...) weave width would be governed by the Weld Size and "Split Layer" limitations of Table 3.6, the travel speed (see: 19) limitations of Table 4.5, and the Heat Input/Volume (9) limitations of Table 4.6
Over the years as the "Weld Engineer" on specific projects I've come up with weave width limitations that I have found to work in my applications.  They were not limitations listed on a Weld Procedure Specification (WPS) because of a code requirement, they were listed on the WPS because of the "Engineers" requirement (mine).
I'm sure you came looking for a "hard" number you could use to determine weave or oscillation width.  But that is a number that you would need to calculate given your specific requirements.
PWC


2 comments:

Gerald Austin said...

Paul,

A common "requirement" that I have heard spoken of in the past is 2.5x the core wire diameter for SMAW. I understand the heat input limitations etc. related to weave beads but was curious if you have ever seen an actual code or material specification (not project specification) with this exact requirement? I have only seen it in SMAW electrode A5.x specifications.

Toolmanwelder said...

Another thing to consider is manufactures specifications, I had this same issue many years ago and contacted the electrode manufacturer and their response was; they would not warranty any weld that was more than 6 times the core wire diameter of the electrode used.