Procedure Question

Date 02-03-2012 21:25

In the welding process GMAW-S, I have qualified a procedure using a modified GMAW-S process (Surface Tension Transfer), this process is used for welding root pass only in open butts. When using this mode of transfer the equipment has both Synergic and Non Synergic modes, The Synergic Mode is factory set with only a trim setting control by welder, the voltage is controlled in regards to ESO via Voltage sense cable. In the Non Synergic the welder can control the background current, peak amps tail out. With this said the orignal WPS settings, example WFS/AMPS and volts are set the same in both modes (Disply on calibrated Equipment) but behind the scenes in the Non Synergic the other varibles can be adjusted, Do you see this to require a new procedure? Even with this not being new technology just as pulse,not sure when essential varible in these backgrounds settings are removing out of code limitations.

By Lawrence (*****)

Date 03-22-2012 18:50 Edited 03-22-2012 18:55

Frankly.. STT is so complex I think Lincoln needs to answer your question.

But I like to talk about GMAWP, and haven't climed upon the soapbox for many months, Sooo

In my opinion if you are using options like "hot start" or "crater fill" Those things ought to be incorperated into the WPS.. Unless you can show that the power output to the arc and wire feed rates are within the percentages allowed in your original WPS, and I think it would take a mad scientist to show it.

Again in my opinion... Every whistle and bell, every knob, every numbered program needs to be represented on the WPS, and this means having been proven out through the PQR process.

WPS/PQR's should also reflect the Model number of your Lincoln STT power supply and the program updates for each individual program. Program variables with GMAWP power supplies sometimes change several times within a model year.

What I'm saying above is that Two production GMAWP/STT power supplies with exactly the same settings and touch pad options for hot start, trim, or crater fill etc. may not be producing the same/similar outputs to the arc if they are different models or even the same model but have different program updates. How do you *know* the outputs are the same? Or at least compliant with code variables? I sure don't ..... Lincoln might.

They are simply way more complicated than power supplies that run strictly on CV power with wire feed speed and voltage being the main factors.

Hows that for stirring the pot?

By jwright650 (*****)

Date 03-22-2012 19:46

>Hows that for stirring the pot?

Didn't you mean to say..."stirring the puddle"? :razz:

By Lawrence (*****)

Date 03-22-2012 21:13

Naah...

Tats GTAWP

Another whole crock of crap altogether :)

By magesh

Date 03-25-2012 06:31

sub: Different PQR make one WPS

1. We had conducted 3 individual PQRs for the positions 2G,3G & 4G (code AWS D1.1). According to this PQR's, we prepared one WPS. In this WPS, we have mentioned the positions as F,H,V,OH.

2. The welding parameter has been calculated by taking the average of those 3 PQR readings. The final result will be calculated by increasing and decreasing 10% of value of average result.

This WPS was submitted to the client. They've given the following comments after reviewing it.

" I am having trouble understanding how you can take 3 different weld tests and use the average for your WPS, especially when the welding parameters and the weld sequence vary considerably, which means it is outside the requirements of the standard and also the "single PQR" it was based on. Could you please review the documentation and resubmit."

Please help me in explanation regarding this comments. Where I can get the answer in the code book.(AWS D1.1)

Thanks.

By ozniek

Date 03-25-2012 12:19

Hi RM

I think you should start a new thread, seeing as you are asking a "new" question. At any rate, here is my opinion.

If it takes substantially different parameters to weld in the different positions, then I would specify these seperately within the combined WPS. So you will have the different parameters (+-10%) for each position in your WPS. It takes a little more work in the table, but makes it easier for everyone else, including the welder. With this approach, the client will also not be able to fault your WPS. (I would probably have made a similar comment if I reviewed the documentation.)

Regards
Niekie

By PWCameron (**)

Date 03-27-2012 01:50

Niekie's right. Your WPS will not be practical to the user (and will not comply with Clause 4).
Example: If one PQR had a GMAW wfs of 280ipm 3G up and another had 550ipm for 2G, an average of those would be of no benefit to the Welder.
Your parameters should be listed by position. They should also be written so that when I use the highest WFS/current with the lowest voltage, and the lowest WFS/current with the highest voltage I'm able to make a sound, acceptable welds.

Don't focus on writing procedures that include the widest possible ranges... focus on making them useful to the end user.
PWC

By Shane Feder (****)

Date 03-28-2012 00:12

Excellent response Paul.
Too many people seem to have lost sight of the reason for WPS's.
It is not about trying to fit the most information on the least amount of paper - it is about writing a document that the welder can understand and follow and by following it ensure "sound weld repeatability".
Cheers,
Shane