Help on fillet joint

[medroberts]

Guys,
I have just started to weld using my new esab inverter, but Iam having trouble with slag inclusion ? The welding set is CEP+, 140amps,E6013 4mm esab Miltrode electrodes and hot-start on 3 secs. (arc-force turned right down to settin 5 out of 0-99. The pics attached are: No1 -fillet on scrap steel in workshop. (Very happy with this). But second and third pics have flaws in the weld as you can see. The steel being welded is 80x8010mm angle iron. The trouble is that I cannot see what Iam doing wrong in the 2&3 pics as apposed to the first (practice weld). Iam trying to keep the electrode at the correct angle, but still no joy !! And to top it all, I cannot get the grinder in there to reweld. please can the experts help me out ?

 

[Engineer1964]

Looks like your welding from outside the angle inwards, if thats the case then the result will be contamination in the weld as you go inwards towards the corner.

Another idea is that arc length is too wide, you need to keep the arc tight to control the slag ideally i would keep it the same distance as the diameter of the rod, and give that a go

What you need to do and i'm not sure 100% as i rarely stick weld is start off in the corner and work outwards so any slag, or contaminates get blowned outwards and not mixed in with the weld.

I'm sure thats what the issue is here but i'm sure a more knowlegeable MMA man will reply soon

As for cleaning, a sharp cold chiesel and a few wacks with a hammer may clean it up a bit

 

[medroberts]

Thanks Engineer 1964 (Gerry),
Thanks for the advise. Iam welding from the inside corner to the outside of the fillet. I take onboard , what you say about the arc length being to great. Shall work on reducing this..... Any advise is greatly apprecated......... Anybody else like to comment ?
Thanks, Med.

 

[medroberts]

Tino, Snowcat,FJ ,Technical AL,
Please could you pass comment, as info is greatly apprecated..........
Med.

 

[GrahamGKD]

Sorry, I'm not any of the experts you mention but…. I think arc length as well. You should be able to see where the arc is going while you are welding. I wonder if the arc is getting too long and then getting ragged in the places where you are getting inclusion. The material you are working with doesn’t look particularly clean - MMA isn’t as critical on clean metal as TIG or MIG but it wouldn’t hurt to clean it up a bit? The practice piece with the very good weld looks a bit cleaner?

 

[nickk]

i agree ,& suggest when you've cleaned all the slag out use a smaller rod @ the max amps for that diameter[say 2.5mm 80 amps to finish the weld run then run another bead with the larger rod as a sealing run to cap it to full profile.

 

[scarecrow]

you might be slowing a bit as you see the corner coming which will allow the weld pool to get in front of the rod. the rod should be always on leading edge of the weld pool if you slowdown the pool can get out under the rod this is usually a problem at the start of the weld but can happen any time
140 amps is a little low for 4mm rods have you tried 3.2mm which might be more suitable for what you're doing

 

[medroberts]

Graham GKD,
Yes you are correct Graham, I could see the arc dancing to either side of the joint. But I didn't know what was causing this.
Med.

 

[medroberts]

Scarecrow,
Iam welding from the centre outwards. I can see the arc dancing from one side of the joint to the other where the defect has occured. Do you think my arc gap is to great like the others ? What amps do you think to be correct for 4mm rods? The inverter which I have bought is a ESAB aristo 4000i (400 amp), I have been using my pickhill 210 before, so getting used to the difference betwwen AC & DC. Thanks, Med.

 

[scarecrow]

you could also be experiencing ark-blow which is one of the problems with DC welding magnetic clamps will cause the ark to wander damp rods also affect it
dirty steel can also cause problems by protecting one side from the ark
I still think your biggest problem is not enough amps most 4mm rods are rated 50to 80 amp
so try cranking it up a bit
most of the problems with fillet welding happens at the start as you have quite a bit of steel to melt and a small area to fill before you have to move on try starting on the outside where there is less steel to heat and more room for the weld
experience welders usually start with a longer ark. lengthening the ark will increase the amps and put the heat into it quickly this will come when practiced so play around with it a bit

 

[medroberts]

Scarecrow,
The amps are on 140, did you mean to say 150 to 180 amps ? The hot_start function seems to work well, giving good pen @ the begining of the weld. I find if I up the amps I get a lot more spatter. Other posters say to weld from inside to outside to prevent slag from contaminating the weld pool ?

 

[stew]

yeah med, around the 160amp range is usually about right for 6013's @4mm. maybe try turning up your arc force a tad, and get in really close for your start @ the corner, puddle a little then move off into ur run. as suggested above maybe best remedey would be run a 2.5mm rod hot to burn out the slag trap, then cap with ur 4mm. look good welds though

i bet a 3.2mm 7018 would run sweet for that job too.

 

[medroberts]

All arc welders,
Any more advice ? If I turn up the amps by much more(above 150), I get a lot of spatter and weld does not peel, to hot? Slag difficult to remove. Arc-force turned off, as rutile rod(6013) ?

 

[oilcooled :)]

are u having the same problems doing the same joint with the pickhill, ? ? im glad my inverter doesnt have arc force, one less thing to nt have to worrry about

 

[snowcat]

there are a few causes which may be causing this.. some have already been mentioned..

Firstly prep, doesn't look like you have removed the mill scale, theres a reduction in heat input into the joint.

secondly id ditch the 4mm and root in with a 3.25, your trying to fill a joint by the looks all in one hit, you would be far better to concentrate on a good sound tight root, even with a 2.5 then worry about subsequent passes personally id hit it in 3.... ignore the weave..

thirdly as mentioned inclusion's like that can be caused by arc blow, cold materials, contaminants damp conditions, alteration in rod angles, all sorts..... It happens to us all grinding back and remedying faults is a fact of life sometimes.

My tact however would be to clean the materials, root in with either a 3.25 or 2.5 rod... keeping the arc tight and the weave low, once your happy thats sound then concentrate on the caps, with your inverter id be tempted to ditch the 4mm and stick with the smaller for the minute....

once your roots are good the caps will just flow...

 

[medroberts]

Oilcooled-Yes it does occur sometimes with the pickhill, but not as often.I think this is because I have done alot more with that (I have more of A feel for that). The inverter is new to me and will take some getting used to the settings etc.... I have never had a DC welder before.
Snowcat- Thankyou for your advise, greatly appreciated. So much to learn !! I will try 3.25's and let you know.

 

[backpurge]

As has already been stated try to avoid starting in the corner, start on a outside edge then run into the corner.

If you start in the corner you have a lot more material to soak up the heat as you are trying to get your arc established.

Get your amps up and keep as short an arc as you can and alter the electrode lead angle to "hold" the molten slag back and stop it impinging on the weld pool

 

[oilcooled :)]

4s are not suited to what your doing, i use 3.2 70% of the time, 2.5 20% of the time nd 4s 10% of the time, unless im at a bucket .. . then the 4s come out in all force

 

[medroberts]

Backpurge,
I thought that the general consensous was to weld from the corner outward to the edge of the angle ? And that if done into the corner , it would cause slag inclusions.. Or am I not understanding somthing ?
Oilcooled: why would 4mm not be suitable ? please explain further....

 

[oilcooled :)]

well its only 6mm angle your welding, in the second photo, i never ever needed to use anything over a 3.2 on all steels up to 10 mm wall, it just doesnt seem necessary to use a big 4mm rod on section that isnt especially heavy, thats just me tho,