Hey Gerald,
Some good points regarding the slag freezing etc. Is there any evidence that indicates a wide weave over the thin solidified slag on the leading edge of a puddle causes or increases the chance of trapped slag?
This is apart from the "code requirements" you stated above which do not prohibit weaving in which the code has already allowed. It is my feeling that one of the leading causes of slag in completed welds is bead contour and NOT the slag that remains on a properly contoured bead. Of course my estimation is solely based on observations of welding performance tests I have observed and welds I have made. The energy used to melt slag in my opinion would be much less than what is required to melt steel. Often times a bead that required a large abount of effort to remove the slag is a bead with convexity or undercut that prevents the arc from melting the underlying metal due to the sharp notch formed by the bead shape at the toe of the weld.
It is my opinion that the statement in 5.4.4 says what it says. Its context is in relation to ESW/EGW. It indicates two conditions that must exists, freezing slag and stopping of welding. If the logic of the paragrph were applied to smaw it would be hard to put a root in with xx10 electrodes using a whipping technique or even a fill or cap pass using a whipping technique.
5.30 does require previously deposited weld metal to be cleaned and I agree with that requirement fully in conditions requiring code compliance.
The width of the bead has little to do with anything in my opinion when using SMAW. I have seen beads with greater heat input used filling up a joint than the faster thin weave bead put over it as a cap. As mentioned before, the stringer bead has some advantages when it comes to length of bead vs length of plate. This is very evident for this people that seem to think a 3/32" rod is good for a 3/8" plate.
On conditions in which heat input is a concern, travel speed should be controlled and not witdth of weld. In many cases those are related however I am pretty sure I can make what appears to be a stringer with too much heat input when filling a groove joint.
I am sure there are some cases in which controls above and beyond the code are justified. As an inspector I try not to get into that. As a welder, I want to know why.
Have a good day
Gerald
http://weldinginspectionsvcs.com/