Lincoln NR212

By Lawrence (*****)

Date 11-16-2009 19:50

I'm still having trouble with a batch of donated 5/64" NR212.

It runs ok horizontally but in the vertical position we are having real problems getting a flat contour on fillets and 45 degree grooves in 3/4" A36 with backing. Very ropy with poor sidewall fusion, slag entrapment and overall poor appearence.

Anything over 100 ipm and the pool just drops away. Very voltage sensitive too. 1/2 volt takes it from usable to unusable.

We are trying everything the Lincoln "innershield guide" says to do, including wierd drag angles for the vert-ups.

Most side bends are fracturing centerline from root to face (overalloying?). When they break it's always in two pieces and long visible crystals are observed in a way I've not seen before.. When I get a good camera I'll post a pic.

I know the max thickness for the stuff is 3/4" and we are using a minimal 45 degree included angle and a small 1/4-3/16 root opening to maximize dillution.

The stuff is years old no doubt as it is donated... But the spools are bagged. I just don't know if we are wasting our time or it's just a matter of improper technique.. We have no problems with gas shielded (ESAB 710X) in all positions with unlimited thickness but the self-sheilded is really being a problem.

Any advice is welcomed .

By ssbn727 (*****)

Date 11-16-2009 23:52

Hi Larry!

Remember that NR 212 is a fast freeze wire much like an E 6010 - 6011 rod, so it's not going to run like the dual shielded wires which tend to mimic low hydrogen characteristics...

First question is what polarity are you using, and I ask this because it should be DC electrode negative, or straight polarity (DC-) for this wire...
What's your ESO? Are you using a nozzle on the gun? because there's no need for one with self shielded and your Electrode Stick-Out should be around an inch and a half from the contact tip at least... Are you running it in CC or CV? Also, you don't have to run it like gas shielded with respect to work or travel angle either... Are you getting enough of resistance as the wire tries to start the puddle to form? In other words, should feel a bit of a "recoil" when the wire starts to form the puddle if your Electrode Stick Out length is far enough away from the puddle as well. ;) I hope this helps a little. :)

Respectfully,
Henry

By Lawrence (*****)

Date 11-17-2009 02:51

Thanks Henry.

To me the stuff really runs like inside-out SMAW..

We are running DCEN and CV with Miller CP302's and the tube to work distance is at or near what Lincoln recommends. We have tried a little longer and shorter also without any real big difference.

Some guys like a nozzle on just to keep the stickout consistant <they use it like a gague>.. Others just run the bare contact tip.

Some guys run a slight downhand angle -5 degrees or so when going vert-up... others keep it perpendicular to the work.. no big differences.. I've tried it both ways.

The "recoil" thing you mention is something new for me, I'm really glad you brought it up . .. At the low WFS needed to get the stuff to run uphill, if the voltage is even 1/4 volt too low that recoiling will sort of be sporatic throughout the pass,with the arc sputtering a bit.. Can't imagine thats normal or good. Usually a little voltage tweak gets a more consistant arc and puddle but the fusion at the sides and keeping a flat profile is still quite a trick.

We did get some side bends to pass today but i'm not pleased with the visuals.

By Blaster (***)

Date 11-24-2009 20:50

Lincoln literature says it is similar to NR 211, though it is a -G wire, not a -11.

NR211 is rated for vertical down. While it will do uphill, 211 isn't crazy about it due at least in part to its light slag. I would imagine the 212 may like VD too.

By Lawrence (*****)

Date 11-24-2009 21:49

Blaster... I agree 100%

The 212 does run smoother downhill... The catch is that downhill FCAW looses it's pre-qualified status and I would have to run a PQR in order to use it that way.

By Blaster (***)

Date 11-25-2009 15:23

I see.

Again comparing to 211, 211 has a pretty broad recommended wire speed, but none-the-less it really doesn't like to go over 100 IPM vertical either (for an .068" diameter).

Moisture pickup may be a problem. I threw out a pallet load of NR202 and E71T-1 that we had stored in a humid environment for probably 10 - 15 years. I don't know its orgin, but it was old when we got it.... just guessing but likely 20 years plus. Most of the inner bags had miniscule rub holes, though a few looked perfectly intact. None of it ran right though. It looked like soap suds were on top of the puddle during welding and pin hole porosity was a problem.

By Lawrence (*****)

Date 11-25-2009 16:52

Than I'm not crazy! Sounds like we have some common experiences.

We run the 5/64 212 at about 90-99 ipm... over 100 and all hell breaks loose.

Our donated stuff was in the same condition... A pallet dropped off.. We threw a bunch away that was obviously rusted and contaminated.. Other boxes looked pretty good, some looked excellent.. Talked to my Lincoln rep (a very good guy, Rob Stinson) Who checked the #s and said the wire was 2003-2004. Maybe there is a shelf life issue.

Happily I got to talk to Hobart, Esab and Lincoln at the Expo in Chicago last week and each are going to drop me a spool of their favorite self-shielded FCAW electrodes wire to demo.

I don't mind giving the students something a little extra hard to run from time to time... But this batch may just be unusable...

By joe pirie (***)

Date 11-26-2009 05:38

Throw it in the trash it is worthless unless your welding on the trash cans.