some tube welding

[davidjohnperry]

I'm not the best tube welder with the mag welder but its a drastic improvement from what I started out on its structural but is a end cap and will all be tested. The tube was rolled welded at 29 volts wire speed 6-7 this is from memory but take a look

 

[MoreWellie]

Still learning here so don't assume I am right but in the top picture the weld at the top right looks like it is cold along the pipe side just from the way it curls under at the edge. The one round the end of the pipe looks good to me

I will be interested to hear what someone with some proper experience thinks as I am probably talking toot

 

[davidjohnperry]

I'm still learning to mate might be where I got stuck on the rotation and held to long

 

[davidjohnperry]

oh I get u no it curls a bit coz there's a little gap in the tube so I did a root first think my root may of been a little big

 

[Welderpaul]

in the top picture the weld at the top right looks like it is cold along the pipe side just from the way it curls under at the edge. I will be interested to hear what someone with some proper experience thinks as I am probably talking toot

The weld you are taking about has been run in too hot and/or too slow and has slumped - 'rolled over'. It's a fail on a visual and needs to come out. Looks fairly sizeable tube and should have been done in three runs depending on the size of the weld specified?

If you are rolling tube when welding it you need to be really careful that you are always welding at the 12 o'clock position. It's easy to get ahead of yourself and end up basically doing a vertical down weld and just laying weld metal on top of the parent metal.

How is it 'tested'?

 

[davidjohnperry]

u t I think it did come back and was re welded but not by me

 

[davidjohnperry]

but I'm still training so I've learned bits but tube i find very difficult welding

 

[Brad93]

Why not just stand that part up vertical so the weld is then in the 2F position. Much simpler.
If I was to weld that with mig in positionI would probably have a helper roll the weld out if You don't have a rotator.

 

[davidjohnperry]

only coded to plate and tube in the flat where I work I have other outside work but there long expired

 

[Revs1972]

I haven't seen one of those cruciform end connections on a brace for a long time. Takes me back to the old days when everything was overspecced.

 

[Richard.]

It's very hard to tell from the pic but it's as Paul said a poor transition of the weld toes on the horizontal. Major stress riser if toes don't blend smoothly.
Top looks undercut and the bottom looks lapsed.
I'm not sure I'd say you have run it too hot but you have run it waaaaaaaaaaaay too slow and you've been weaving. Basically you've attempted a huge fillet in 1 pass and unfortunately when doing such things gravity will always win.
You could of done a 2 run root and cap or even a 3 run.
Big welds in single passes are compromised by the heat input needed to achieve them.
Low toughness from large grain structure.
Multi passing refines the grain structure and an equally sized fillet done in multiple runs is a much stronger joint and you'll not be fighting gravity to keep your weld toes and under cut smoothly blended.