Advice for 1F weld scenerio...

By Blaster (***)

Date 11-18-2010 03:15

What size wire?

Without knowing your wire diameter, it is hard to say but my guess is that you have too much voltage for your wire speed. You want to dial it down until you are shorting, then add a little at a time until the transfer just cleans up. This will give the optimum arc for good metal transfer and penetration and fusion. You loss penetration and fusion if you continue to add an excessive amount of voltage.

Are you travelling too slow? If your root thickness is much more than about 1/8" thick you may be.

Your are on DCEP CV right?

The 1/4 x 1 backing should be fine. BTW that sounds like a 1G, not 1F. And you are probably using 30 cubic feet per hour rather than 30 PSI.

By TJohnson Date 11-18-2010 07:54

Sorry, left that out on accident. .045 dia.

By TJohnson Date 11-18-2010 08:20

And, again, you are correct; 30cu.ft. per hr.

By Blaster (***)

Date 11-18-2010 03:38

Are the plates bevelled? What angle? That is a big root opening. If that is a square butt, I wouldn't try to a single pass root, but rather two beads for the root.

By 803056

Date 11-18-2010 04:15

I am puzzled that no one has asked for the classification of the FCAW electrode.

Al

By Blaster (***)

Date 11-18-2010 05:59

Me too.

By TJohnson Date 11-18-2010 08:07

Good point! Sorry, left that one out by accident in the process of trying to explain this dilemma. I understand this is a certification test weld as welderbrent had described, and he, obviously is correct, although the gap between the root opening had been changed from 15/16" to 9/16". The othe missing information is the electrode diameter, which is .045. Our goal here is to establish the cause of lack of fusion, as well as slag inclusion at the root. This has happened repeatedly not only with myself, but, other students as well. Thanks for the quick responses as they are very encouraging!

By TJohnson Date 11-18-2010 08:10

Square butt, two root passes...

By welderbrent (*****)

Date 11-18-2010 04:17

TJohnson, (and your fellow students),

WELCOME TO THE AWS WELDING FORUM!!

First, (Blaster, take note) you are running a FILLET Weld Root Bend Test Plate per D1.1, Clause 4.28 or 4.25, Figure 4.33 (Option 2).

The Plate pieces should be 3/8" X 3" X 7" long, square butt groove with a 3/8 X 2" backing plate UNLESS it is to be RT tested and then it would be 3/8 X 3" backing plate. The space should be set at 15/16" gap between plates. Not to be confused with root gap.

Now, it would appear that first off you have the wrong backing plate.
Secondly, you have too narrow of a gap between pieces.
Third, after you run your FILLET along each side you can run the middle and balance of weld to fill the gap in any position you want. This is mainly used when doing a vertical test or overhead. After running the fillets you may fill the balance of the space in the flat position. The test is mainly checking your root penetration/fusion at the junction of each of the test pieces with the backing bar.
Fourth, I would agree with Blaster that you may have the machine set wrong. Double check your welding parameters for the wire size you are using.
Fifth, I would also agree that you possibly are moving too slowly trying to get too much fill in one pass, especially with too narrow of a gap.
Sixth, you have too much angle on your drag. Go to around 15-20* instead.

Good luck. Keep practicing.

Have a Great Day, Brent

By Blaster (***)

Date 11-18-2010 05:59

Ahhhhh, making sense now.

By TJohnson Date 11-18-2010 08:17

Tomorrow we have the intent of reproducing the test weld as per requirements. Why we used the 1/4"x 1" backing plates in the first place was as per instructions. Backing plates at 3/8"x 2" will be incorporated. I am determined to resolve this and greatly appreciate all the input and will be sharing this with fellow students first thing tomorrow morning.

By ssbn727 (*****)

Date 11-18-2010 09:18 Edited 11-18-2010 09:21

Hi TJohnson, and "WELDCOME TO THE WORLD'S GREATEST WELDING FORUM!!! :) :) :)"

You still have not revealed to us the AWS classification of the FCAW electrode... Do you understand what this means as a question that is important to eliminating all of the possible causes for your defective welds?

In other words, Al, "803056" is most definitely correct (None better in here to point out such nuances IMHO!) in stating his puzzlement as to why you did not include the AWS Electrode classification for the type of FCAW filler metal you are currently using... So, if you are using for example a E 70 T X-X ( the zero after the number seven indicates welding position which is flat and horizontal only) filler metal as opposed to an E 71 T X-X (The number one after the number seven indicates all position deposits), then you're using the correct filler metal for the 1F position... Btw, the number seven represents the tensile strength of the filler metal being used...

However, if you are using an all position filler metal such as an E 71 T X-X wire, then you may not have your machine settings optimally set for that type of filler metal especially from a penetration perspective, and would be better suited to use the proper recommended FCAW filler metal specifically designed for that particular position.

Now another important question would be to verify if the WPS (Welding Procedure Specification) states what is the specific type of FCAW filler metal to use for this test...
So you may want get that aspect clarified also... Other than that, you have been given some sound advice by the others who posted also. Best of luck to you. ;)

Respectfully,
Henry

By welderbrent (*****)

Date 11-18-2010 12:54

To add a little to what Henry just said so well, I have found on many occassions that using the all position (E71) wires at top end of their ratings for amps, volts, wire feed, etc while using in the flat position is not as desirable as using the E70 series which is made specifically for flat and horizontal. "Worm tracks" and other discontinuities can be eliminated simply by changing wires. Even though you are in their range and position standards they don't perform quite as well.

So, as Al and Henry suggested, it would be nice to know the classification. And the other info is very helpful as to seeing where you may be having problems.

Good Luck in the new effort.

Have a Great Day, Brent

By TJohnson Date 11-21-2010 00:32

Thank you for this advice. It seems I had better have my facts straight before entering the forum. Don't get me wrong as my hat is off to you veterans out there. Your prodding for correct answers are not going unnoticed. I am in the process of re-evaluating my approach to this application and shall return with a more educated update. I do take this all very seriously as it sets the tone for the "real world" experience to come. Thank you again, I will be back!