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Up Topic American Welding Society Services / Technical Standards & Publications / welder performance qualification for D1.1
- - By dodgeball01 Date 07-17-2009 00:07
The company I work for has a job which requires ASTM A514 to be welded to ASTM A514 and to ASTM A572 gr 50.  Due to the higher tensile strength of the 514 the company is purchasing higher strength Metal cored wire replacing the FCAW wire normally used.  Due to the required thickness of the material the companies welders have to retake a welders performance qualification for unlimited thickness.

My Questions are
      (1) does the welder performance qualification test plates have to be A514 material or can they be A36?
      (2) does the wire being used for the welder performance qualification tests have to be the higher strength wire used in production?
      (3) if the wire does not have to be the higher strength wire then does a metal core wire have to be used or can any wire for GMAW be used in the welder performance qualification test?

I have talked to several CWI's on this and have gotten different answers from them.  So if you have any input on this please feel free to give your opinion.
Parent - - By MBSims (****) Date 07-17-2009 01:05
Replies:

(1) No, A-36 plate can be used for the test plates.  A change in base metal is not an essential variable for welder performance qualification (See Table 4.12).
(2) No, a lower strength electrode will qualify for use of higher strength electrodes (and vice versa).  A decrease or increase in electrode strength is not an essential variable for welder performance qualification (See Table 4.12).
(3)  No, a metal core electrode will also qualify for use of solid electrodes (and vice versa).  A change from metal core to solid, or from solid to metal core is not an essential variable for welder performance qualification.  Both metal core and solid wire are still the GMAW process.  However, a change to flux core would be a change from GMAW to FCAW, so that would require requalification (see Essential Variable #1 in Table 4.12).
Parent - - By bmaas1 (***) Date 07-17-2009 23:10
Yes this is absolutely correct.  Remember you are only qualifying the welder and not the process or material.

Brian
Parent - - By 803056 (*****) Date 07-18-2009 17:53
Be forewarned, I believe the next release of the filler metal specifications for GMAW and FCAW will place the metal cored electrodes in with the flux cored electrodes. This may change the picture somewhat, i.e., metal core would no longer be considered to be a variant of GMAW.

Best regards - Al
Parent - - By MBSims (****) Date 07-18-2009 19:22
Not sure I understand.  Use of metal cored electrode would not fit the definition of FCAW.  Are you saying the A5 spec would specify the electrodes are for use with a separate process called Metal Cored Arc Welding (MCAW)?  If so, I would consider it to be a variant of GMAW until AWS redefines the process in D1.1 or A3.0.
Parent - - By 803056 (*****) Date 07-18-2009 20:21
I'm hedging my bet, but I believe you will see welding with metal cored electrodes grouped as gas shielded FCAW rather than GMAW. It would be consistent with gas shielded FCAW in that it is a tubular electrode. Clearly the committee has pondered this for several years. Does the core provide shielding or doesn't it? Do the core elements merely deoxidize the weld or do they serve other functions?

I'm not willing to bet my grandson's college fund on the change, but this is what I've heard through the grapevine.

Best regards - Al
Parent - By bmaas1 (***) Date 07-18-2009 23:07
The CWB has it grouped with FCAW.  Has since I remember.

Brian
Parent - - By HgTX (***) Date 07-20-2009 15:13
AWS changed the metal-cored wires from FCAW to GMAW classification sometime in the 1990s.  Made somewhat of a mess with the codes, which didn't all keep up.  D1.5 didn't get completely straightened out till 2008.

Hg
Parent - - By drewp29 (**) Date 07-27-2009 22:21 Edited 07-27-2009 22:31
So, I think I have read this somewhere, but I'll ask it anyway: Table 4.12 addresses GMAW-S as a separate process from GMAW, but what about going from FCAW-G to FCAW-S? Would the welder need to be requalified? Is FCAW-S considered a different process than FCAW-G?

Drew

Never mind . . . found the thread I had read:

http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=74213;hl=fcaw-s

It appears that since Table 4.12 does not specify, the change from FCAW-G to FCAW-S would not require welder requalification.

Drew
Parent - By HgTX (***) Date 07-28-2009 18:25
It's a different difference.  The S in GMAW-S stands for short-circuiting; the S in FCAW-S stands for self-shielded.

Hg
Parent - - By Taintedhalo (*) Date 07-28-2009 18:45
All right back to the main question here. Isn't Table 4.12 just for if the operator is already qualified to a WPS not for the actual WPQR(WQTR).Look at (6) on table 4.12 it says (If used in the WPQR test) that means the operator is already qualified to the WPS for the job.

I know the diffrence in welding A514 compared to A36 is two totally diffrent animales. With A514 their is a lot better chance of hydrogen cracking that is why their is a 48 hour hold before VT inspection. And if the operator just lays down pass after pass not letting cool below the maximum interpass temp. A514 becomes very brittle. IMHO the essential veriables for the WPS are the same for the WPQR(WQTR), other wise aslong as I can weld two pieces of 1" a36 together with a ER70s-6 wire with out pre-heat then I can weld all farrow magnetic steels (Mild Steels).

Let me know if I am way out in left field. And where exactly it is found.
Parent - By motgar (**) Date 08-24-2009 01:39
taintedhalo,

When you state "operator"; do you mean welder or welding operator?
Parent - By ssbn727 (*****) Date 08-23-2009 22:39
Just a slight clarification if I might add... GMAW as well as GMAW-S are both the same process but, the real difference between the two are the methods of transfer...
In other words: Short circuiting, STT (Surface Tension Transfer) or RMD (Regulated Metal Deposition), Globular which really isn't desirable, Spray, and then there's GMAW-P that  could conceivably represent a whole slew of different types of metal transfer under the "umbrella" of Pulse depending on whether, or not one sets the various options available in a variety of brand name power sources which may or may not include the same options or capabilities to varying degrees of repeatability... For instance, some of the older power sources offered what is now relatively speaking a very limited overall pulse frequency capability, and for the most part when compared to current offerings, no real level of customizing the waveform to what most current power sources can achieve presently through a variety of built in design features that vary from brand name...

Then there is also the fact that the older commercially power sources couldn't even produce true square wave rectification as compared to what is essentially the current minimum standard - capability wise in order for a commercially available power source to even be considered as offering basic pulse transfer... Then there's variable polarity pulse transfer which inone of it's earliest forms was developed by NASA...  Then Synergic Pulsing which simply put (and I'm using only one example here so, please bear with me Larry ;) ), is considered when the parameters which determine arc power are programmed into the unit, so they can be adjusted using a single control as opposed to the adjustment of individual parameter controls such as found on a traditional GMAW power source...

If pulse welding, the arc power parameters are: wire feed speed, background amperage, peak amperage, pulse frequency and pulse width... If non-pulse welding, then the arc power parameters are: wire feed speed, arc voltage and inductance, and these parameters may differ from one manufacturer when compared to another as well as having or not having other specific parameter controls separate from the example I used which can be found in the earlier versions of Synergic pulse controls...

Then there's what is known as "Synergic Pulse on pulse" which has been around for some time although is relatively new on a commercial basis, and a similar concept is being applied to GTAW also whereby the arc power parameters are combined into either one or more individual controls, or combined to lessen the overall amount of individual parameter controls in order to program as well as store these customized parameters in the CPU, or in a separate storage device found in the power source...This also depends on which brand manufacturer design configuration is being used, and how it interfaces with the person who can either customize the program design via laptop computer or in some cases, just chooses from pre-stored & pre-programmed parameter choices available to the operator which can also be individually fine tuned even further with adjustments that will for instance, trim the voltage slightly enough to produce a slightly different result depending on what the operator is seeking as well as other fine tuning options.

The wire feed pulse rate is also controlled with a separate set of individual controls, and some power source configurations even have separate controls for pulsating the flow rate of the shielding gases being used also... So, until all of these parameters can be considered into separate methods, or different classes of various methods of transfer, and then converted into some form of standardization with respect to one being able to somewhat calibrate power sources from different manufacturers in order to achieve a more refined capability of repeatability with regards to parameter settings resulting in identical weld deposition & quality characteristic profiles from power source to power source no matter which brand name is being used - these sometimes "mind blowing" variations from the standard methods of metal transfer found in both GMAW and more recently, in newer Synergic Pulse on pulse GTAW offerings will continue to give the various welding code committee bodies headaches for some time to come!!! ;) :) :)

Respectfully,
Henry
Parent - - By wall2112 (*) Date 08-23-2009 20:05
i dont know how after reading 4.21 and 4.7 and looking at table 4.8, that the information given on use of a36 plates is correct.

A572 is group II, A 514 is a table 4.9 steel. could somebody tell me how the wire and base material dosen't matter.
Parent - - By MBSims (****) Date 08-23-2009 21:40
The question had to do with welder qualification.  4.21 says the welder must follow a WPS for the base metals used in the qualification test.  4.7 and Table 4.8 apply only to the procedure qualification for the WPS used, so a WPS for A36 would be needed to perform the welder qualification test.  However, that does not limit the welder to only the base metal and WPS used in the test.  The range of qualification for the welder is based on Table 4.12.
Parent - By wall2112 (*) Date 08-25-2009 00:08
4.21 also says right after that,all of the wps essential variable limitations of 4.7 shall apply. then you can go to 4.7.3 and it directs you to table 4.8 .  that table tells you what wps you can write from which pqr's you have. and i dont know what he has but it looks like to me that he should have a 1 inch a514 to a514 pqr and a 1 inch a514 to a572 grade 50 pqr welded with the metal core wire. and the operators must take the same test for welder performance. also since 4.7 shall apply read 4.7.1 . and if you look at table 4.8 it is set up so if you weld the higher strength wire it certs you in the lower ones. if you go high on the pqr it lets you go down from that on the wps. you can go down but you cant go above. read what i have wrote and think about it, and then see if you see it the way i do. not to say you have to, everybody interpets things differant. have fun with it, i do.
Parent - - By motgar (**) Date 08-24-2009 01:36
dodgeball,

Not sure if anyone has mentioned this to you.  Not sure if you have access to a copy of AWS D1.1:xxxx.

There is a key paragraph in the commentary.  Take a look at C-4.1.2; certainly something to take into consideration.

 
Parent - By MBSims (****) Date 08-24-2009 19:16
Good information.  I see it suggests either prior experience welding Q&T steels or "instruction and training", but does not actually mention or suggest separate qualifications.  C-4.18 also suggests the welder be given "instructions" on welding Q&T materials.
Up Topic American Welding Society Services / Technical Standards & Publications / welder performance qualification for D1.1

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