6g plate weld

By Lawrence (*****)

Date 09-15-2009 18:28

Matt..... Welcome to the Forum!

6G is a pipe position and cannot be done on a plate.. So we need to know what exactly your position is.

also tell us more about the specific problems you are having..

Problems with consistant penetration at the root? Blowing holes? Lack of penetration (showing hard lines on the back side) ??

Are your 6010 electrodes sticking? (arc foce adjustments)

Are you running stringer beads or weave beads?

Are they failing visual or bend tests..

What is your instructor telling you about what he sees in the bends or the visuals..

Tell us these things and you will get a ton of help.

Also tell us the diameters of the rods you are using for both root and fill... Prolly 1/8th but it's best to be sure.

The folks here will get you through this :)

By matt_risor Date 09-15-2009 20:09

Lawrence…I understand 6G is a pipe position, but my syllabus and instructor refer to the position as a 6G plate weld. The plate is at a 45 degree angle (/) and we are to weld from the bottom upwards. It is to simulate the transition from the 6 o’clock position to the 3/9 o’clock position on pipe. I hope this clears up the confusion for everyone
My root is not quite there yet because it is a new position but I’m making good progress. My main problem is the 7018 of the hot pass and filler passes. For my hot pass I use a zig zag weave pattern with 3/32 rod and stringer filler passes with 1/8 rod. This is the same process I have used with all my other out of position welds ( vertical up, horizontal, overhead) with success. The main problem I am having is very convex un-uniform beads. Also, once I reach about 2/3 up the plate (3/8” x 7”) my arc changes direction and shoots down and digs in rather than depositing metal. I do not believe this is arc blow because I moved my ground to my coupons and it had no effect on the problem. I have also tried many different rod angles with no success. Also I am running my root pass at around 82-84 with 1/8 6010, my hot pass at 95 with 3/32 7018, and my filler passes at 110 with 1/8 7018
Thank you
Matt Risor

By Lawrence (*****)

Date 09-15-2009 20:34

Matt

Excellent!

Your instructor is giving you good things to practice.

I would still consider arc blow... you have the classic signs.. ropy, convex face with increasing difficulty toward the top of the joint.

Take your work lead and make three winds around the leg of your table or the vertical portion of your holding fixture. and then put the clamp on the bottom of your work piece and weld away from it... If this does not work make the winding go on the opposite direction.

Take a little extra time to pause at the edges with the 7018 and move a bit more quickly across the middle.

Arc Blow can be a funny animal.. Comming and going from one day to the next, depending on what the power usage is in your nearby environment. Also double check the quality of your work cable ends, both at the lug at the power supply and at the clamp itself.. If you see any slop or freyed copper wire bits.. cut about 6" inches from the cable and make a fresh connection (with your instructors permission).

Sometimes reducing current can help with Arc-blow as well but your numbers are already at the low end of the range so you don't have much room there.

It's an interesting problem.. Keep us posted on your progress!

By ssbn727 (*****)

Date 09-15-2009 20:57

There is your problem Matt!

Your "hot" pass is being run with too much amperage if you're running it at 95 amps for 3/32" E-7018... You need to bring the current down 10 amps at the very least!!! And even eighty amps is okay for 3/32" diameter E-7018... May I ask what brand are the E-7018's? Heck, I know quite a few welders who weld 3/32" diameter E-7018 on pipe @ 75 amps and yet, I personally prefer eighty five amps myself since I like to run it hot and fast! ;)

What you're experiencing is a form of "thermal' arc blow as opposed to magnetic arc blow as a result of excessive current I believe... How far down are you able to consume the 3/32" diameter electrodes before the stub becomes a bright orange color and you can no longer keep it at the angle you want, and the flux coating is peeling off from the excessive current?

Also, you say that you're using a zig-zag weave technique... Are you hesitating enough at the toes of the root long enough to wash the puddle on to the bevels (in other words, are you positioning the center of the electrode right on the toe of the root pass so that the puddle actually washes new molten weld metal past the toe and on to the bevel on both sides of the joint?), and are you NOT taking your time as you go across from toe to toe when you are stacking your weave and are your weaves tightly spaced?

I ask this because, if you are following this technique like I described above with less amperage, you should have much better success at depositing the type of welds that are desirable for that type of practice position and joint configuration!!! Btw, one final question... What is the included angle of the joint that you are welding on???
I look forward to your response! ;)

Respectfully,
Henry

By Nalla

Date 12-04-2009 23:40

Dear Friends
Bottom Line is- If good sound weld acheivable proven by RT/UT, will ASME IX will accept "Plate-6G" position?
Just curious? If it is smply for traning purpose, it is indeed good effoert.
Thanks

By dringge (*)

Date 12-06-2009 16:10

I have my students do these same exercises on plate before I let them move on to pipe. Good practice and less setup time between plates when making rookie mistakes. And less expensive on my budget.

By Shane Feder (****)

Date 01-28-2010 00:28

Hello guys,
Rodofgod may be able to offer his opinion on this as it is happening in Britain but major structural engineering companies (some working on power stations) are giving a single 6G plate test and saying it covers all positions instead of the code recognised 3G + 4G.
Not sure how they get away with it but as Rodofgod posted a while back there are a lot of non ASME code compliant goings on over there,
Regards,
Shane

By js55

Date 01-29-2010 17:23

Shane,
Not exactly sure how that works either,and it may be a perfectly acceptable challenge of a welders ability, but if it ain't ASME compliant, and the specs insist upon ASME compliance, they sure better not say so.
Or at least not end up on a witness stand.