D1.1 WPS GMAW Question

Date 08-03-2008 00:41

I would hope Lincoln could supply a chart for both weldors and inspectors for this type of setup, otherwise it sounds like a huge hassle for everybody involved. Without a chart of mode/wirespeed amperage and voltage values, I'm afraid both will have to depend on the 5 second interval to verify the settings conform to the WPS, because I don't believe you can specify non-standard settings (anything but amperage/wirespeed and voltage) in any D1.1 WPS qualification. Although wire speed in place of amperage is allowed on the WPS form, you're still at sea for voltage readings. Putting modes on a WPS would be problematic anyway since the modes are reprogrammable by anybody who understands the programing parameters (machine selling point). I would check with Lincoln, if they intend this machine to be considered for code environments, it behooves them to supply the info required to write a WPS, at least for their own programing. If they don't supply this information, I don't see how you can get around the requirement to record voltage, since a change beyond 7% either way requires a new WPS. So as a practical matter, assuming no help from Lincoln, I would have the shop weld sample joints and report the wirespeed and voltage used and take it from there. Yeah almost defeats the advantages of prequalified, but at least you don't have to do mechanical testing.

By 803056

Date 08-04-2008 13:47

Hello Eekpod;

I agree with your approach that the WPS should be machine specific if you are using the pulse mode with GMAW. As for the canned programs, you have little control over them or the parameters and it is unlikely the manufacturer will provide you with the specifics of the program since it is most likely protected by patents or copyrights.

If the welding machine utilized canned programs, I see nothing wrong with simply stating the program number provided it it tied to a specific machine model and specific software that can be checked by a third party. In other words, I should be able to turn on the machine and see some type of display that will confirm the welder is using the same software version and program that you listed on the WPS. The values displayed by the welding machine's volt and ammeters are average values and little else.

The only means you have of monitoring the welding parameters is to connect the machine to an oscilloscope to measure the peak, background values of voltage, duration, slope, etc. Pulsing parameters are too complex to be controlled using the traditional ammeter and voltmeter. To compound the problem, each manufacturer use different parameters to produce the desired results in the laboratory. Depending on the welding machine, the parameters can even vary while the welder is welding. Manufacturers have done very little to provide a useful means of monitoring the welder's operations.

Best regards - Al

By Lawrence (*****)

Date 08-04-2008 15:20

EEK!

This may be knit picky

But if your controlling your arc length by a "trim" control with that lincoln than you are using GMAW-P which is a CC/CV hybrid and not strictly speaking a CV output.

I'm really hoping the 2008 D1.1 will clear this issue up and just allow GMAWP to be prequalified or at least be much more clear about power output restrictions in section 3.

By jwright650 (*****)

Date 08-04-2008 15:26

That's what I'm thinking Lawrence......I suggested to a local fabricator that they use the conventional settings and leave the other alone since they work to D1.1 and wish to make use of the prequalifieds.

By eekpod

Date 08-05-2008 10:38

Thank you for all your reply's.
I got in touch with our Lincoln Rep. and they'll be here tomorrow to explain to me more about the functions and settings for the machine.

For ease of use, I think I'll make a seperate WPS for the welders, so they know what settings to look for on the machine. I have already bent some coupons made with those settings so I know they work. It may not completly comply w/ D1.1, but more importantly I know the welder has the machine set correctly and that it will do the job right, vs him not understanding what he's looking at, and weling out of the range that's required.

As far as the hybrid cc/cv issue. I know you guys have brought this up before, and to be honest with you, that's way over my head. The manual says for program # xx that its a cc, and #x is a CV. I have to go with that for now, I'm not an electrical engineer to determine when/ how it actually works. I feel confidant with what the manufacturer's manual says.

Thanks Chris

By Lawrence (*****)

Date 08-06-2008 04:39

Chris

You may be right.

I have lincoln powerwaves and they can do both CV mig in regular mode and GMAW-P. The "trim" function adjusts arc length in pulsed GMAW mode... but the same digital indicator is often used for voltage control purposes in traditional spray and short circuit transfer, and the same pot is used to make the adjustment. The only difference is the program selected.

By miggun

Date 08-06-2008 16:22

Chris,

We have just gone through the exact same situation. We have 4 of the Lincoln 350. We have created our own WPS by just adding in the Lincoln settings. We are passing 1" on the root / face bend procedure, Also Longitudinal bend procedure. I can attach the WPS it is created in excel so it is easy to input values. Here is the setting's for our Lincoln Mig's.

Lincoln mig settings
Mode - 19
% WFS - 215
Volts Trim - 1.1
Pre Flow 0.3
Post Flow - 0.5
Run In - 150
Start - 0.5
Arc Control - -3.7
Crater - OFF
Burn Back - 0.03
Spot - OFF
Gas Cup Size - ½
Travel Speed - 20

Hope this may help!
Dave

Attachment: 3GsteelVdownWPS.xls (493k)

By eekpod

Date 08-07-2008 11:50

Thanks Miggun, looks nice a layout for all the extra options that the machine allows. I'll use it as a guide to tweak my own form, but I see you ended up where I was considering going.
That's whats nice about this forum, stuff like that. I really appreciate your reply and time.

BTY, I did meet w/ the Lincoln rep yesterday, and they walked me through the characteristics of each program for GMAW. So I feel better about what's going on. It is a nice unit, and can do a lot of things, it's just that sometimes all the bells and whistles get in the way.
Chris