PQR FAILED

[EngrRodri]

Mates,

Please help. My PQR done was failed in hardness and impact test.
Details was
API-X60 Pipe(P1,Gr2)-16 inch Dia, 23mm Thick
Flange - A707 CL3 L5,(Not included in ASME sec 9 material grouping),16 inch Dia, 23mm Thick
GTAW-ER70S-2 -ROOT PASS & HOT PASS
SMAW-E7018-FILLING & CAP
CODE B31.8
NO PWHT Because as per code above 32mm only requires PWHT
PREHEAT done is 150 degress C,

It was passed in bend test and Tesile test... In Impact test test it passed with -18 C for parent metal (Flange&Pipe), Weld metal (SMAW), HAZ(SMAW & GTAW)but it failed on Weld metal (GTAW)

Please ask on your expertise advise.
Thank you

 

[metengr]

What was the failed hardness?

 

[metengr]

Did you have the lab check and see if weld defects in the root/hot pass were the cause for the failed impact specimens? Normally, ER70S-2 has adequate notch toughness, 20 ft-lbs at -20 deg F. So, either you had lower than expected preheat when pulling the root pass or weld defects.

 

[weldstan]

Without a defect in the weld metal, I have only seen a failure in GTAW deposited ER70S-2 weld metal when travel speed was exceedingly low (approximately 1" per minute or less.

 

[gtaw]

One point to remember: Make sure the filler metal is capable of meeting notch toughness as well as the base metal. No sense wasting time with materials known or not known to meet notch toughness requirements.

Not all filler metals are created equal.



Best regards - Al

 

[EngrRodri]

Metengr....
the harndness VHN shall be below 250VHN however the test had exceeded to 280 for value HAZ.
I only used ER70S-2 Because the design temp is -18 only and i had experience passing it using x60 and same filler wire.
however because as client procedure than more than 10mm shall have seperate impact test for GTAW & SMAW...
thus gtaw deposit only is 3.33 mm so the third party laboratory decided it to make -34 due to subsize... which i disagree

WELDSTAN
before the impact test.. it was tested in RT and it pass..
I also make practice for welder to make it fast travel speed in gtaw & smaw welding

GTAW
the material MTC has value impact value of 50kj in -60 degress
and filler material (ESAB) as per MTC is also capable to do the test temperature

 

[weldstan]

Subsize specimens need only have a temperature reduction when the available Charpy test specimen is less than 80% of the size of the PQR coupon. One must ask why you chose to independently qualify both the root pass GTAW process and the SMAW fill. You could have impact test qualified both processes together provided both weld metal deposits were included in the specimens.

 

[EngrRodri]

weldstan (Materials)
That is the hardest part because of client standard procedure to make separate qualification for GTAW & SMAW if the Thickness of test coupon is more than 10 mm

 

[weldstan]

Could you not have qualified your GTAW process on 3/8" wall material or did you Client prohibit that as well?