SAW AWS classifiction

[JamesKerr]

Dear Experts,

If I qualify a PQR for SAW and the manufacturer’s suggested AWS classification is F7A6-EM12K, can I write on my PQR F8A6-EM12K providing that all the tensile tests pass with minimum tensile of 80,000PSI?

Or can I weld on a material with a minimum specified tensile of 80,000 PSI with the designation F7A6-EM12K as long as the tensile tests recorded on the PQR are above 80,000 PSI?

The background is, I have a welding procedure that I want to use on SA612 normalized plate (-50deg F). The AWS tensile strength designation is low, but the procedure has passed all the tests with the lowest tensile tests being 84,891 PSI and the highest being 91,000 PSI. My understanding of Section IX QW 153 is that if the PQR passes the tensile tests then it is acceptable, however I’m not sure if it would only be acceptabel for the flux/wire material batch.

Best Regards

 

[weldstan]

1. You may not recertify the AWS Classification.
2, You could use the procedure on the high strength material provided the PQR was made on the same P No. and Group No. as the SA 612 material since impact testing is required.

 

[DekDee]

In addition to Weldstans comments-
1 A PQR is a record of what was actually used on the qualification coupon.
If it was F7A6-EM12K then that is what must be reported on the PQR.

2 You can't weld an 80K material with a PQR for 70K just because your tensiles on this particular batch exceeded 80K.
The manufacturer is only guaranteeing the tensile strength meets or exceeds 70K so the next batch of wire you buy may have tensiles of 71K.

If impacts are required:

QW-404.35 A change in the flux/wire classification
or a change in either the electrode or flux trade name
when the flux/wire combination is not classified to an
SFA specification. Requalification is not required when a
flux/wire combination conforms to an SFA specification
and the change in classification is
(a) from one diffusible hydrogen level to another (e.g., a
change from F7A2‐EA1‐A1‐H4 to F7A2‐EA1‐A1‐H16), or
(b) to a larger number in the indicator for impact
toughness, indicating classification at a lower impact testing
temperature (e.g., a change from F7A2‐EM12K to
F7A4‐EM12K)
This variable does not apply when the weld metal is exempt
from impact testing by other Sections. This exemption
does not apply to hard facing and corrosion‐resistant
overlays.