PQR Qualification

[kukes2]

Our company is going to qualify a welding procedure on a 1/4"thick plate coupon of SA-387 P91 material welded with the GTAW process using ER-NiCr-3 filler rod in the 1G position with no PWHT.We will use a 99.90% argon mixture for shielding and backing.Preheat will be 200 degrees F and interpass at 400 degrees F.It will be an open butt vee groove design welded fom one side.

Does anyone have any comments or suggestions that i may have missed in the above paragraph?

 

[metengr]

No, your stated conditions are acceptable, and similar to what EPRI has proposed for welding of Grade 91 material with no PWHT.

 

[weldstan]

I assume that you are qualifying the procedure per Method 6 of the latest NBIC. It is noted that Filler Metal 82 is specifically stated. I don't know if this was merely and example or the listed trade designations are mandatory. metengr?

Good luck on passing the bends. I would recommend maximizing the area of the deposited weld metal.

 

[metengr]

Filler metal 82 was merely stated as an example of one of the filler metal classifications referenced in the NBIC. The NBIC has been revised for 2017 to reflect the filler metals as examples per classification.

There will be no issue passing bend tests under Section IX on 1/4" thick, Gr 91 material. This falls directly in line with Welding Method 6. In fact, numerous user organizations have already qualified this method and has been used for in-service repairs since January.