In the WPS for Welding a ASTM A-333

[alejo2003]

In the WPS for Welding a ASTM A-333 GR 1 & 6 pipe for carry ammonia anhydrous liquid at -30 deg C, we used a E-6010 for the root pass and a E-7018-1 H4R for the fill and presentation layer.
After the clean of the root pass we heat the weld at minimun 130 deg C with a torch.
In the PQR we got the Folllowing: 1) Rx: No defects
2)Tension test: 79000 and 76000 psi tensile strength, 3)Hardness and tension bend: OK 4)Charpy at -35 deg C: 45 Joules.
What Do you Think?
The values of the impact test are low or what?

 

[grampi1]

Looks pretty normal to me with perhaps the preheat being a little higher than strickly needed. 45J in a 7018-1 at -35C is a pretty good value. We routinely test identical welds at -40C and get between 20J and 40J. I don't have B31.3 in front of me but believe the 45J is more than it requires.

 

[stanweld]

The impact values are about right - especially considering the use of E6010 and its being included in the test. If you need higher toughness, use a tougher electrode (filler metal) for the root pass.