orbital welding

Date 01-23-2009 02:24

Are you welding it open butt or trying to fuse a root in? Is it double up or 360 travel? Have they tried k-rings or consumable inserts? Lots of variables involved and hard to help without more info on procedure and parameters(numbers).

By jonas henry Date 01-23-2009 03:13

360 degree travel, no land, no root opening. I set my parameters about 190 primary, 90 background, and the travel speed, and wire feed, etc as it goes along. I realize excessive heat on the root and hot pass will cause suckback, but it takes that to penetrate. I could be wrong, most likely I am.

By K.Sexton26 (**)

Date 01-23-2009 05:34

Why can't you gap the root to help get the bead pushed thru?

By swsweld (****)

Date 01-23-2009 15:35

It's been several years since I welded with AMI's. I have never butted the 37.5 together like you described. Is that normal these days or is it just the company you are with?

Open butt requires a lot of skill when things don't go perfectly, but gets great results when it does.
Inserts are great too, but more fit up time is required.
J prep, square butt (with and without wire) good joint configs.
Lots of options, I just haven't welded with NO gap on conventional bevels.

Your suck back, is it only at the bottom half, bottom third?

I have pulled root passes with straight current (say 110-120 with no background)and like you describe-180/80 or similar.

Arc volts must be VERY tight on the problem area.
Also, you may try starting at 1:00-2:00 DH progression first and get the bottom over with early before the metal gets too hot(pinching action) and causes more suck back.
Can you leave a slight gap in the bottom (1/16") ? That will help.
Make sure that you have NO lag in the torch assembly.
Try a little more blunt on your tungsten. If that doesn't help try no blunt.
Wire entry at leading edge of puddle, no dripping into the puddle. The wire should help push the root in.

Not a good joint config IMO
Any hi-lo on fit up will wreak havoc on ID.

Sorry that I can't offer more help but that is not a typical J/C in my experience.

I miss working with the machines, AMI, Dimetrics etc.

By spgtti

Date 01-24-2009 16:19

I agree w/ SWS. Run in pulse arc with 2-5 degrees lead angle max. Run arc volts waaay down until the tungsten starts to "Tick"(barely starts touching the puddle without stubbing out) and then back-off one number. Try adding a little wiggle with the oscillation to spread the puddle width. I prefer an 80-90 amp spread between pri/bck and keep the wire down low to where it almost drags and try adding a little more wire to push up the bead. Try about 2.5 ipm travel speed @ the tungsten (thats the speed used for pulling rings).

By jonas henry Date 01-26-2009 01:40

Yes, the suckback is in the bottom, and I will try one with a gap tomorrow. Thanks for the help.

By SWP

Date 01-26-2009 23:01

Years ago I was taught by Dimetrics to run the 37 bevel open root, about 3/32" gap I think, with a small land on the bevel, maybe 1/16", and four tack welds feathered with a grinder. I think we used a very small side to side oscillation. The main trick to deal with suckback on the bottom and excessive dropthrough on the top is to change the wire position so that the wire is up inside the joint on the bottom, and outside the joint on the top. I still have a section of the weld as paper weight around here somewhere.

By spgtti

Date 01-27-2009 01:50

A 15 degree wireblock helps keep from shoving coldwire into the root.

By jonas henry Date 01-28-2009 01:17

Thanks, I'm continuing to use everyone's suggestions and my root beads are looking a little better. Thank you for the help