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Up Topic Welding Industry / General Welding Discussion / Overhead Pulse
- - By TimGary (****) Date 01-15-2014 20:33
I'm working on a procedure for a 6G cert test, using GMAW solid wire pulse, all the way out.
I've got everything figured out except the overhead root.
I have no problem putting it in, but the internal side of the overhead root is always concave.
Any tips / suggestions on getting the root penetration to be at least flush?

Particulars -
Miller Axcess- AccuPulse
.035 - .052 solid wire, ER70S-3
A500 grB square tube - 1/2" wall T
Single Bevel on bottom half.
Pulling travel angle with a whip stroke
Parent - - By 46.00 (****) Date 01-15-2014 22:51
Tim, root concavity is not an automatic fail with many standards.TBH I would try the single bevel on the top half and not use a whip stroke on that part of the weld.
Parent - By Smooth Operator (***) Date 01-16-2014 00:10
I wish the inspectors I've "tested" for would have that approach concerning what's acceptable root .......MOST want to see a 1/8" inside......Flush what's that???????? ain't even in their vocabulary !!!!!!!!!!:yell::yell:
Parent - By spgtti (**) Date 01-16-2014 01:34
All the pipe work I've ever seen done is rooted short circuit and then changed to pulse for the balance of the weld.
Parent - - By WeldinFool (**) Date 01-16-2014 19:18
Hmmm....6G with square tube, single bevel, open root, GMAW-P, interesting...What code are you working with there? What will you be welding on?
Parent - By TimGary (****) Date 01-17-2014 13:15
We build roll over protection systems for heavy equipment using square and shaped tube to AWS D14.3 and additional customer requirements.
GMAW-P works very well for us due to enhanced puddle control and reduced spatter.

Tim
Parent - - By Lawrence (*****) Date 01-16-2014 20:42 Edited 01-16-2014 20:46
Tim,

Axcess has that old RMD mode which is specifically engineered for open roots.  I don't understand the desire for GMAWP.

Lot's of folks run a dual schedule pipe program that employs RMD for the root and a quick trigger change to GMAWP for the cover passes.

As far as concave 6 o'clock sag/concavity...  My experience has always been to reduce motion and get from point A-->B as quickly as possible.  As heat builds (whip stroke) the puddle expands and gravity does it's thing.

Edit:  I think it's probably also important to know if you are proceeding uphill or downhill on the root pass.

If fitup and root faces are consistant... You ought to be able to set your parameters to get the root reinforcement you want with a very slight drag angle and no whip or weave.

I also think you are really going to have to have SUPERIOR fit-ups, root faces and openings to even think about using .052 filler for pipe roots.

I have recent experience trying to get Axcess to work with GMAWP and .052 L56 wire....  It was a complete fail.  This was done with a small army of Miller reps and engineers on hand to guide.    There were some other factors that made the application unique, but the fact was that in the end, Axcess could not make the weld.
Parent - - By TimGary (****) Date 01-17-2014 13:33
I'll have to try the RMD, but I'm concerned about bend/tensile test survivability.
Reduced motion, no whip, high travel speed - good points.
Up hill root and cap on the verticals which is no problem, overhead root is the only issue.
Consistent fit-up and root faces are very important, but the pulse is pretty good at handling slight inconsistencies.
We're having very good success with L56 .052 high dep pulse on our robotics, and I'm trying to spread the wealth to manual process.
I don't understand your difficulties with Axcess Accu Pulse and .052, it runs like a dream for me, at lease in the flat/horz position.
We're seeing 40 -60% increase in deposition rates over .035 spray, with little to no spatter.

Thanks,
Tim
Parent - - By Lawrence (*****) Date 01-17-2014 15:14
Hey Tim,

I AM A BIG FAN of .052 filler for structural GMAW!

Axcess did not like the taste of 88/12    Ar\C02     We all thought it was "nominally" close enough to 90/10 to be ok...  But that just wasn't the case.

Lincoln S500 can take that .052 wire with *Rapid Arc* and make 3/16 fillets that would make your mother proud.  Plus it has built-in CheckPoint data monitoring, where I can have a cup of coffee at my desk in Houston and observe the WFS, Voltage, Lbs of filler per hour and Arc-on time and a host of other data, for every power supply nationwide.   Pretty sweet.

In fact... I can monitor all that data from my freakin phone :)

.
Parent - - By TimGary (****) Date 01-17-2014 20:34
Yup, the Lincoln set up is pretty cool.
Miller's works well too.
I recently qualified a procedure for GMAW-P, Rapid-Arc on a S500, to run a 3mm fillet in 16 ga sheet, with .052, at 70 IPM TS.
We run 90/10.
Parent - By Lawrence (*****) Date 01-17-2014 21:06
That's pretty rapid  :)
Parent - - By Metarinka (****) Date 01-18-2014 00:44
how do you maintain shielding at 70 IPM? I was playing around with some 0.1" wall 304SS automated pipe welds, I could get a decent weld up to 80IPM but could never get good shielding coverage.
Parent - - By TimGary (****) Date 01-19-2014 13:31
90/10 AR/CO2 @ 42 CFH with 5/8" nozzle and 45 degrees downhill push
Shielding has not yet been a problem.
Limitations are weld profile quality, joint fit-up and no seam tracking.

Tim
Parent - - By Metarinka (****) Date 01-22-2014 01:45
I guess another big factor is pipe diameter this is 6" and under pipe, so 80 ipm means 10-20 seconds for the entire weld.  The backside was still cherry red when the weld finished.
Parent - By Superflux (****) Date 01-24-2014 18:08
" The backside was still cherry red when the weld finished."
Sounds like an excellent interpass temp for a successful tie-in without having to grind the "start" to me...
Up Topic Welding Industry / General Welding Discussion / Overhead Pulse

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