PQR Requalification for wire size increase.

Date 03-22-2011 15:55

Hi!
I am working with AWS D1.1 2006 edition which is new to me as I am more familiar with ASME and EN standards! Anyhow, one of our fabricators has decided to increase the diameter of his GMAW welding wire from 1.00mm to 1.2mm dia without consultation. All the PQR’s and welder testing were performed with 1.0mm dia Now, looking at Table 4.5, item 10 and also the top of first column “Essential Variable Changes to PQR Requiring Requalification”, does this mean that ‘Any increase or decrease’ requires requalification? Why wouldn’t there just be an ‘X’ in the cell?
Surely, a 0.2mm increase in welding wire size does not require requalification?
Please tell me I am reading this wrong or missing something?

Thoughts Please?
:confused:

By jwright650 (*****)

Date 03-22-2011 16:46

I think you will have to requalify the WPS based upon what D1.1:2006 Table 4.5(10) says....sorry, the code just didn't leave you any wiggle room with that phrase "Any Increase or Decrease". Pretty much sealed the deal.

Out of curiosity,
Did the size .2mm increase do anything to the electrical parameters?
Voltage +/- 7%, Amperage +/- 10%, Travel Speed +/- 25%, mode of transfer, etc....

By jarcher (**)

Date 03-22-2011 16:53

You will have to run a new PQR with the larger wire size. AWS is much more conservative on WPS parameters than EN or ASME.

By 46.00

Date 03-23-2011 21:46

Thanks for the replies, even though it wasn't good news! :cry:

Anyhow, will be re-testing tomorrow hopefully,

John, I'm not on-site everyday, so am not sure of the increase in electrical variables that go with a 0.2mm increase in wire size, but I will check it out! TBH, I wouldn't have thought they would have been outside the % limits!!

Regards

By 46.00

Date 04-01-2011 14:00

Hi All!

John, FYI

1.0mm wire
235-245 A 28-29 V 11.6-11.9 WFS (M/min) 440-460 mm/min travel speed 0.78 Kj/mm Heat Input

1.2mm wire
265-275 A 28-29 V 9.3-9.5 WFS (M/min) 430-450 mm/min travel speed 0.89 Kj/mm Heat Input

Procedure performed 1G 10mm thick plate.