I'm not sure if this is the place to ask this question, but here goes. I know everyone has encountered this before, and so have I. The question is WORM TRACKING in the face of the weld, using gas shielded flux core. I am using a E71T1 with a 75% Argon & 25% Co2 shield, and welding on a A36 type steel, nothing exotic, (where an unobtanium filler would be required.) I would love for someone to tell me cause, and prevetion methods, to prevent this condition. Any help will be very welcome.
Hi rhoople47,
Moisture in the flux is one problem that causes worm tracks. The moisture can get into the flux due to a poor joint seal in the wire manufacturing process, the wire being stored in a damp or humid location, or the wire being unprotected when it is on the spool on the welding machine. Baking the wire before use sometimes helps, and using a slightly longer wire stick out preheats the wire and reduces the potential for hydrogen contamination and worm tracks. Using the high end range of the weld current, slowing down weld travel and increasing the weld size all may help. Just make sure you stay within the parameters set forth in your WPS. Here's a link to the Phoenix Oven site that may be of interest to you:
http://www.phx-international.com/fcw_article.html
Thank you very much. I thought it might be moisture. We have a real need for proper storage around here, and you just aided me in the argument for such. The longer stick out does seem to help also. I found the welder using a stick out similar to that of GMAW.
We were using E71T-1 with 100% C/O2 and found that too fast a travel speed caused those tracks to show up on the surface of the weld, under the slag. Got the guys running a little cooler and traveled slower and all that stopped. The welders were cranked up hot and flying along the joint and the weld didn't have time to let the gasses escape before it solidified completely. We never had the problem with the more fluid E70T-1 at all, only the quicker freezing E71T-1.
John Wright
Hi JWRIGHT,
Thanx for the imput here. After I posed the question and revisited the welder on this issue, he told me of a wire change I knew nothing about. They switch from the TM 72 we were using to The RX7 (Both Tri-Mark wires), without consulting me. The TM 72 was a E70T1 and the RX7 is a E71T1. I'm working on getting the right wire back in now. You're right in saying that the E71T1 cools quicker, and that's why I went with the E70T1. Damn supervisors think they can just order what ever they want. Kinda makes me think, Why am I wrighting procedures. Oh and by the way, the wall in my office has the imprint of my head in it now. Nothing like beating your head against the wall huh.
There were dents in the walls in my office before I started this job and I was wondering where they came from, I guess the previous QC guy had done the same thing. I simply use the column flange right outside my door, it makes so much noise that people from inside the main office come running out to see if a stack of steel fell over or if a train ran off the tracks and into the building. Ok maybe a little exaggeration there, but you get the idea.
John Wright
Ditto!!! Except my office was new so all the dents match my cranium.
I have also seen worm tracking caused by excessive wind. Our shop is right on the ocean with sea breezes blowing right through the shipping doors. It doesn't take much to lose shielding.
Mike
Thank you for the input, I am aware of the 5 mph rule, and that isn't our problem. It is kinda hard to tell a welder, and I was one of them, that they can't have a fan blowing right on them.
Our problem with worm tracks seem to stem from improper electrode angle and/or travel. Many shop welders who use mostly GMAW are not aware that you must keep the electrode much closer to 90 deg. and that it must be pulled. When the gun is stood nearly straight up and not leaned as you pull the weld, the worm tracks will disappear. As I think about this, it may directly related to jwrights response.
Respectfully,
Mike Sherman
Shermans Welding
Our worm tracking problems are usually solved by checking that the voltage is not too high for the wire feed speed, checking the electrode angle and stickout, and making sure the gas flow is correct. Just revisiting the basics is normally all it takes.
Don't overlook that the gas supply lines are synthetic rubber and "inflate" a bit under pressure. I think the regulator runs around 50 psi, not to be confused with cfh. Since the gas solenoid is on the wire feeder, you will get a pressure surge when you first pull the trigger. If the welder hears that the "rushing" noise is too forceful, he may think the flow rate is too high and turn it down. Then when the gas flow evens out, there might not be enough for adequate shielding. I would hold the trigger long enough to check that the flow rate is correct.
Chet Guilford
A gas mix that is heavy on Argon has also been know to add to this problem. We have always been able to eliminate the worm tracks with a little more stickout.
Andy
Well we fixed the worm track issue. I went to a different wire, still a E70T-1 but different kind. I found out from my supplier that we were not the only ones with this problem. We did everything suggested by you, but to no avail. The guys were working with the previous wire for years and didn't have the problem, so tech. wasn't the problem. It was just the wire.
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