I need some guidance with the following issue.
What is the mode of transfer for FCAW??
This is in relation to our WPS's that were returned to us "approved as noted" from a client. In the "Electrical Characteristics" section THEY checked off "Globular". We had left them blank.
The research I have done on this issue from two different welding textbooks doesn't mention anything about mode of transfer for FCAW. It's lists and explains them all for GMAW but FCAW is void, I took this to mean that it doesn't apply to FCAW.
Also on our WPS form, the "Transfer mode" has next to it(GMAW) which I intrepret as only applies GMAW. Just as the sample form in Annex N in D1.1.
So I found two reasons that this doesn't apply.
Then I call the guy who wrote them originally,(who no longer works for us) and ask him. He explains that originally he thought it was globular and wrote them as such, but got so many returns that he changed it. To paraphrase what he said is " it doesn't apply to FCAW, just like it doesn't apply to SMAW".
Which makes sence to me? any thoughts?
Also, where does it say that the WPS HAS to be stamped by a CWI?
By jon20013 
Date 03-14-2007 18:14
Edited 03-14-2007 19:32
Answer to last question first: Unless required by customer or technical specification, no where will you find a requirement for a CWI to stamp the WPS or welder quals.
Second, I have always been told that FCAW would fit neatly under the globular mode but this may be subject to interpretation. On my own WPS' I list both spray and globular. For ASME at least, there is no different requirements from GMAW to FCAW... they are considered under the same set of variables.
Hello eekpod, I'm going to take a stab at explaining this for you. FCAW, in my opinion, should be run in the spray transfer mode. This will truly be determined by the wire diameter, voltage, wire speed(amperage) and to some degree shielding gas. If a given diameter, type of wire and shielding gas combination are used, and the voltage and wire speed parameters are set too low the resulting transfer will most likely end up being globular transfer. I'm sure that you will likely hear other explanations, this is my humble attempt at laying it out simply. Good luck and regards, aevald
I think FCAW transfer *is* complecated.
But the original post mentioned that transfer mode in the D1.1 annex speaks specifically to GMAW and this makes the discussion moot, and closes the case for the purposes of paperwork, if adherence to D1.1 is how you measure compliance.
For interest of arc charicteristics, now thats another matter altogether.
I think most would agree; Spray transfer is defined by an open arc and droplets smaller than the wire diameter. Now I don't know if that is how self shielded FCAW transfers in every Diameter, and D1 Groups Self shield and Gas Shield FCAW together as far as process. I'm not even sure if all gas shielded FCAW produces droplets smaller than the wire dia. when running at optimum parameters provided by the manufacturer.
This Hobart Datasheet says their E71T-1 produces a "spray type transfer" with both CO2 100% and 75/25
http://www.hobartbrothers.com/pdf/datasheets/Excel_Arc71.pdf
I think FCAW is generally considered spray. At least where most run it. Though I've used 1/16" wire on 2" sch 80 pipe in a 5G and I think it was probably globular at that point. Pasted on like SMAW, which I think is essentially a globular transfer, though technically the terminolgy doesn't apply.
Lawrence is right, it relates to droplet size, and there will be transitions in FCAW like GMAW. Though not with the radical spatter associated with GMAW and not as distinct a change. You can actually see the pinch effect.
I've always listed it as spray/globular on my WPs's, since globular droplets can form from destabilizations in the arc. Especially the colder you run it, and with semi auto applications.
Hello Lawrence, you brought up a point that hadn't even entered my mind when I responded to eekpod's post. There are 2 types of FCAW processes, I was thinking strictly in the gas-shielded FCAW mode and hadn't even thought of the self-shielded process. As you said that opens up a considerably wider range of variables and considerations. Thank you for pointing that out. As to the code language, I would do best to leave those details to others such as yourself. Thanks, Lawrence. Regards, Allan
I agree that molten metal transfer for FCAW it is very complicated....reason being the voltages/currents/gas mixtures that promote spray, globular and some other modes of transfer that I don't fully understand come into play all at once while the arc is on and the electrode is melting off. Noticably spray is more of a hissing sound rather than the sound of war between the wire and the puddle.
I agree with John about sound and additionally, very little noticable spatter. I don't think you can get into spray mode either using 100% CO2, can you?
The rules change a bit with FCAW.
Thanks for all your input so far gentlemen.
Lawrance that link you refer to definitely mentions spray transfer for their wire.
That brings up a question. Why does the sample WPS and most others then list GMAW in paranthesis?? (GMAW)
Should it not be there?
Maybe it should say "Electrical Characterics" (GMAW,FCAW). This sounds more accurate because it sounds as if both globular and spray can/ may be accomplished by either process. Although they are different processes, that might make people think they are the same.
I'll stay posted, thanks Chris
Hello All;
The real issue with ASME is whether the mode of transfer is short circuiting or not (paragraph QW-409.2). Switching from globular to spray or to pulsing is not an essential variable and does not require requalification of the WPS. The issue is if you change from globular, spray, or pulse (as a grouping so to speak) to short circuiting or if you switch from short circuiting to globular, spray, or pulsing. To repeat myself, you can switch from spray to globular or pulsing or vice versa without having to requalify the WPS. It is perfectly acceptable to list (all three) globular (G), spray (S), and pulsing (P) as being the transfer modes on the WPS. If not G, S, or P, then you would list it as short circuiting (SC), however, I don't believe I have every seen anyone run FCAW in the SC mode.
I agree with the other postings that there is no requirement in ASME to have the WPS or PQR signed by either a CWI or SCWI unless the project specifications or contractor's QC/QA manual invoke the requirement.
Best regards - Al
Mornin' Al,
I don't think Chris actually stated which code he was referring to, but I think he may have been looking at D1.1 because he referenced Annex N about halfway through the original post. That said, D1.1 does consider FCAW and GMAW different processes and from what I'm reading, ASME doesn't seperate the two. I agree with Al about the Short Circuiting not being a prequalified type of transfer.
No mention of a CWI signing off, but it sure cuts down on the questioning, documentation and burden of proof of the "qualified person".
In the ongoing quest for the truth, I contact the wire manufacturer Lincoln Electric maker of Outershield 71 Elite.
They say: "I would put a big N/A in the type of transfer box on the WPS. "Type of Transfer" in my estimation applies only to MIG welding not FCAW, TIG, Sub Arc, STick, ect. Much like the box for voltage when using stick welding procedures."
This certainly makes things as clear as mud. I have one side saying it could be both globular and or spray, and the manufacturer saying it doesn't apply.
I am currently trying to figure out who marked these up in the first place, and see what there reason was.
Yes, it is D1.1 thanks Chris
I think your confusion stems from the fact that you are considering two different issues. That which Lincoln addressed has to do with an acceptable code compliance, and their advice, IMO is acceptable, though maybe not to some inspectors.
The rest of the discussion was really centered around opinions of the FCAW process itself, aside from any code definitions.
I'm a bit confused as to why this is so complicated as well. The original question was what will satisfy code. Maybe I've missed something, but I have not seen any code language that says transfer mode *shall* be recorded in a D1.1 compliant FCAW PQR or WPS.
Sub-arc is closer technically to GMAW than is FCAW and It does not require a notation of transfer mode on a D1.1 WPS.
Just because a piece of FCAW product literature says the stuff performs in a spray mode does not mean that one must address the mode in a code compliant WPS.
I'm enjoying this thread though... Lots of good questions.
Can FCAW with C02 shield gas produce spray transfer? Why not? E6010 stick rod can. (at about the same voltage if you think abou it) The fluxing componants in the tubular wire provide an atmosphere condusive to spray even with C02 or Self shielded FCAW. This is why stickout and preheat of self shielded FCAW is so critical. The impacts are just not quite the same as with 75/25.
Edit: Having blabbed on about how noting transfer mode is not "required" I took a look at two FCAW SWPS:
(AWS B2.1-1-019-9R SWPS for C02 Shielded E701T-1)
(AWS B2.1-1-018-94R SWPS for Self Shielded E71T-8)
Both SWPS section for electrical characteristics note mode of metal transfer to be "spray or globular"
I don't know if they "had" to note transfer mode, but they sure did.
Good point on 6010 Lawrence. This is an interesting thread.
Lawrence, your onto something with that last comment. Which by process of elimination I was coming up with as well.
I'm saying to myself, "self, what makes it required to be listed on the WPS", so I go to D1.1 Annex Q and look throught list of "Contents of Prequalified WPS" and it's not listed.
It apears maybe we all just felt that because there was a option to check something off on the form, that most people either picked one or both and went with that. But as far as the code says I don't see that it's required for FCAW.
Lawrence, you mentioned B2.1-1-019-9R, what code is that to, and is it REQUIRED to be listed on the WPS. I'm only concerned about D1.1.
The SWPS (Standard Welding Procedure Specificaiton) mentioned above conforms to D1.1, but is an extention of AWS B2.1 Specificaiton for Welding Procedure and Performance Qualificaitons. The SWPS was prepared by the AWS committee on Welding Qualificaiton and Approved by the AWS board of directors.
SWPS are a response to industry that needs procedures but for some reason may not be able to qualify them themselves. SWPS have been qualified, often by a number of different organizations contributing to procedure quailfication.
Thre have been a number of good threads here on the forum about SWPS... Try a word search.
Some SWPS are also accepted by ASME code committees, (some are listed specifically in Section IX for example) usually with some provison that the procedures be proven by some sort of testing before production begins.
You may conform with more than the required data... But not less.
Lawrance , thanks for that reply, but it doesn't sound as if it will help me w/ this per say. I'm trying to keep it simple and to the point about whether or not it's required, and if so where does one come up w/ the answer.
BUT, in the meantime I believe I may have found/ discovered where this issue surfaced, and low and behold open your books to the sample WPS's in Annex N and look at the sample WPS for FCAW supplied by our friends at AWS. THE "GLOBULAR" BOX IS CHECKED!
In my best imitation of George Castanza from Seinfield I say "AH HAAAAAAA!
Who doesn't refer to the sample examples in the code when we have questions about how something should appear? I know I do, and that's most likely the culprit that led alot of down this bumpy road.
So, question, how did the auther of the sample form come up w/ that determination to check that box? Yeah, it's just a sample and the info. should not be used for production, but this is clearly a way to possibly confuse people. Also, how can you guys justify leaving that box not checked, when the sample says it should be? Huh? huh?
Lastly, I did a search through this site and the mode of transfer for FCAW has not been properly/ sufficiently answered since 2003. Go to the top of the page, click search, type in "transfer mode FCAW" in the keywords box and you'll see a big long list of everytime this came up since 2003. I didn't see any definate answer.
Am I obsessing on this issue, yes. Am I a man with a mission, yup. have I spent too much time on this, probably. But I hate it when I can't find what would appear to be a simple answer.
Thanks for your time, Chris PS I got another diamond by my name because of this :)
I wouldn't stake my life on what's given as a sample WPS in the back of the book...
Hg
i would agree, annex n is informative only, not part of the code
Lawrence, I think You hit the nail on the head, one of the goals in formulating the flux for wire or covered rods is getting the spray transfer. I don't know jack about the codes, but I see where Lincoln is coming from, You don't short circut flux cored wires, so weather the transfer is "short circut" or "globular, spray or pulsed spray" [asuming these 3 are grouped together in the codes] isn't aplicable. By specifying FCAW the transfer wil be spray ideally or spray with some globs if the parameters are anywhere near right.
Good point JW regarding the Annex N. I missed that and the connection to D1.1. A big opps!
A point regarding ASME Section IX, it does differentiate between GMAW and FCAW by making the type of electrode, i.e., solid versus tubular, an essential variable with regards to procedure qualifcation. Nice slight of hand that is missed by a lot of contractors when writing or implementing the WPSs on the job site.
So now you're a "paint" man, huh?
Best regards - Al
Don't know yet....<grin>, grades haven't been posted yet.
To wrap this issue up and put it away for good.
1) As Lawrence mentioned earlier, and I finally discovered, for D1.1 Table 4.5 item #14 "A change in the mode of Transfer" does not apply to FCAW, it only applies to GMAW. So it is NOT REQUIRED to be addressed on the pre-qualifed WPS form. I have since amended our WPS form to completely remove it, so it won't be left blank and potential problems come up again.
2) I spoke to the guy who originally checked off the Globular box on our submitted WPS, and he said after checking Globular off on more than half of our submitted wps's, he realized that it doesn't apply and stopped. He thought he wrote a note stating that but there wasn't.
3) N3 pg 337 As far as the sample WPS form in Annex N. I agree they are only examples and should not be used for production, but,,, they are examples, and per AWS "The Committee trusts that these examples will assist code users in producing acceptable documentation." My opinion is that the example shows something that is not REQUIRED (although could be included) and that if left blank might allow other to determine why it's blank for FCAW.
4) N1. pg 337 "The WPSs and PQR's are to be signed by the authorized representative of the Manufacturer or Contractor." but as the earlier post stated, they are not REQUIRED to be stamped, just signed.
Thanks for all your input and help along the way, Chris
By bctwelding
Date 03-22-2007 01:23
Edited 03-22-2007 01:29
Let me give you my two cents worth on this subject. I suggest that you get your miller welder and feeder set up for flux core 1/16 th size wire. Set volts to 24 and wire speed set to appropriate bead appearance welding verticle up on 3/8 plate. Notice the globular (drops) from the end of the wire. You can turn up the wire and get a not so smooth weld and it appears to spray. Now crank up the volts to 28 or 29 volts and set wire speed to get a good looking weld on 1/2" plate. Even at 300 amps there is a droplet transfer.
What happens when you run 1/16" FCAW wire at 32/33 volts and even more amps?
By p61b
Date 03-23-2007 18:02
We stumbled upon the answer when we accidently put "Spraybular" in the blank...
FCAW is a separate process. GMAW is a separate process. FCAW is not GMAW with a FCAW electrode wire. A Metal Cored wire is GMAW with a tubular wire. FCAW will have a globular or spray transfer by electrode classification ie. EXXT-1, 2 & 3 spray, T-4, 5 globular, T-6, 7, 8, 9, 10 & T-11 spray. Incorrect voltage, shielding gas or stickout may change the transfer.
