So as to start a new thread, will someone who is familiar with 6013 explain the rod to me? I have never burned a stick of it since I started welding in
1974. What is the attraction that causes so many people to use it? Easy to weld? Fast fill? Fast freeze? Guess I need to go buy some and try it. When I want something to stick, I get out the 7018. Guess I could use 6010 for a root pass, then cover with 7018 like the old pipe days, just find it easier to use 7018, less grinding and cleaning out before applying the 7018, although I usually boil out the excess 6010 slag with the 7018 hot pass.
I taught for 5.5 years at The Divers Institute of Technology, training commercial divers to do basic welding. I learned a lot about underwater welding, the most surprising part being that 7014 is the king of underwater welding. This is due to an accident of chemistry that makes 7014 a lower hydrogen rod than 7018, but only underwater.
6013 is usually plenty strong for most applications. It is not low hydrogen so not good for welding high strength steel. But then most low hydrogen rod has not been kept dry enough to be low hydrogen when used. The big attraction for me is that it is easy to restrike an arc. The rod does not burn back inside the flux like 7018 does. So it is easy to run a tack weld and then run another tack without having to break the flux off the end of the rod so it will restrike.
6013 is low strength - well below other welding rods - and not that tough either, surely? For anything temporary you want to be able to knock off with a club-hammer, 6013 is your rod. They do burn smoothly on any machine and you want a run-out about the same as the rod length (whereas Basic 7018 you want a run-out about half the rod-length(?)). Richard S
I have trouble with 6013 having a very fluid flux which loves to run under the weld, while 6011 doesn't have this problem. Now, I'm a humble hobbyist so this may not apply to people who have the training, but fwiw 6011 may be easier to work with, offering similar strength, for the occasional weldor...
6013 is definitely not fast fill as there is no iron powder in the coating.
6013 does freeze quickly but not as fast as 6010/11.
6013 is a low penetration rod which IMHO makes it unsuitable for root pass work or on steel that is rusty or covered with paint or is otherwise dirty. I do not like it for tacking for these reasons unless the base material is very thin or I want a tack that will sit above the base material for removal by grinding with minimal admixture with the base metal. The characteristic that is most unique about 6013 is fast follow. This is most useful when using high travel speeds to stay ahead of the puddle and avoid overpenetration and burn through when welding thin sheet metal. It welds well downhill which is also good when you want to leave your heat behind. Similar high travel speeds using 6010/11 will often result in skips as the puddle fails to keep up with the arc. I seldom use 6013, IMHO it is a poor choice for most work, but I do keep a small amount of 6013 on my rig (DC CC power only) in 1/8" and 3/32" and also some 5/64" which is useful for fine work on thin material. 6013 is good for thin work in the field that is normally better done with a wire feeder in the shop. IMHO 7018 is the best rod for almost everything and I need a good very reason to use anything else. Good Luck, YMMV
60ksi is 414MPa So yes, you don't meet many plate steels with that strength.
However, I can say this from my own look in a metallurgy lab. - Rutile Stick (6013) has non-metallic inclusions which look as big as dinner-plates when you look at it under a microscope at 500X. They would be an unacceptable stress concentrator at higher strengths. So the only way is to lower the strength. But then here is the problem... On begining systematic work on weld metals, the starting point was fairly horrible remelted structures with low properties. Impact toughness is the property you really want to have way up there. Pursuing that, the metallurgical design arrived at gave a very fine structure as-welded. Which had several good features. Not least of which is that structure is not only very tough but also strong.- of which on the "mechanicals" side not only was it tough but it was strong. That's fairly much "hitting the jackpot". So for Rutile Stick, the only way to lower the strength is to drop out of the strong tough structure which particularly Basics (7016, 7018, etc) have. The 6013's have a weld microstructure which is coarse and therefore neither tough nor strong.
So there you have it - a temporary weld which you can readily break with a club-hammer.
As a BTW - with heat-treated steels you tend to have to trade between strength and toughness. Creating a very fine microstructure is the way to get both.
Even more BTW - the weld microstructure with this and other advantages is so desirable that great efforts have gone into trying to work out how you could have the same in a mill plate. Thermodynamicists, you name it, have worked on this. Not easy... No-one has seen a way yet, last as I heard. Anyway, that's digressing - back to the point.
OTOH, at welding school doing break tests on fillets, I have tried putting 6013 fillets in the press without nicking (notching) them first (as you would if you have any healthy wish to learn about you) and I have seen the plate tear out - a thin about 0.5mm to 1mm (20thou to 40thou) layer * where the steel is very low quality * (but only in that case).
And yet again, weld performance can be most limited by fatigue performance under fluctuating loads - which is not, I believe, much affected by the type of welding rod - it would "level" the performance rating with 6013 not much disadvantaged...
The "higher strength" but still common plate steel here is S355, (355MPa nominal yield strength), which would be 51ksi yield against a
6013's 60ksi. But the plate is likely to overmatch the strength, whereas the 6013 will stay low near the min. required. In general you can end up with the weld taking all the deformation, which makes it easy to break with a club-hammer...