Hey guys, I have a little problem that I seem to not be able to control at the moment.
Here's the current problem - Welder A is welding a 12" Od sphere x 7/8" thick. Set on a positioner and in the flat postion, welding while positioner is turning. Gun is set on a fixture and no "hand" movement is involved. Wire is Hobart .062" E71T-1M H8, amps 250, volts 27, 75/25 gas, flow shows >50 (gage may be broke, just discovered). Welder A called me back to the station to do Mt because he's suspecting a problem. Says some flux is coming off easily, other parts are having to be chipped and ground off. After removing slag, he noticed some indications but could not confirm what it was. I did MT and only picked up a few elongated indications but could not confirm if slag was present. He ground the indications just slightly, and indications dissapeared. Conclusion - could not confirm if slag was present or not.
Suspicions were brought about by welder B and rejected slag lines last week. No info on parameters for welder B, but slag was present in almost 3/4 of weld. Welder B is less experienced than welder A, so technique may be a major cause. My hunch with welder B is that the weld was rolling over and trapping slag and he could not see it after removing the slag from the weld pass. Still, we've had FCAW problems in the past and now everyone is gun shy about using it.
Any tips on what could be the problem?
Whats the speed on the positioner, I ran into the same problem a couple years ago where the welders were using a track welder, the travel speed was increased and the problem eliminated. could be all that you need to adjust.
I'm thinking about a couple of things
250 amps is at the lower third of operating parameters for 1/16th FCAW electrodes
Larger Dia. E71T-1 electrodes in the flat position have more issues at the weld toes than E70T-X electrodes when they are run at the lower ranges.
Slow travel speed (possibly as mentioned above) coupled with minimal heat input may be contributers.
If all the work is flat it may be wise to consider an E70T-X with the basic slag system that is specially designed for excellent wetting at the toes.
If "no hand movement is involved" how can technique be a major cause"?
Really sounds like a process control thing.
thanks for the replies guys.
Maybe technique was a poor choice of words. I guess position of gun in relation to axis would be more clear.
Ok, so as for the slag rolling under- need faster travel speed, correct?
What about the slag that was very difficult to remove?
The welder has since switched to .045 and says it's running so much better now.
Lawrence's suggestions were the first thing that came to mind for me as well.
More importantly!!! How's the music and band going?
It's still trucking along. Our rhythm player has left us, so I'm picking up the slack there (singing and playing) and we hired a keyboard player. Taking a month break now, cuz guitar player is skiing in Canada for a couple of weeks.
You can check us out here - www.myspace.com/tinstartexasband
Wow, I can't believe you remembered that!!!
Our 1/16" E71T-1 runs best at 325amps, around 28 volts and 3/4"-1" ESO, the slag just lays there on top. You can literally just brush it off with your welding glove when you're done welding.
This forum is 1st class. I really appreciate all the help.
Forum
