CSA Z662 - CVN PQR requirements

[JasonLouie]

I have a CSA Z662 weld procedure that used the following materials in the PQR:
A 333 Gr 6, 406.4mm OD, 21.4mm thickness
Root: E6010
Fill and cap: E7018-1

Is this coupon automatically qualified down to -45C without conducting the impact testing? I know the A333 Gr6 and the E7018-1 have guaranteed minimum impact energies at -45C, but I am concerned about the E6010 root.

Also, I cannot find anywhere in the Z662 code where impact testing is exempt for PQR coupons if materials with guaranteed minimum impact energies are used.

 

[metengr]

JasonLouie;
I can comment about the use of E6010 and the effects of impact qualification. In general, this subject (the use of 6010 lower strength weld metal in a weld joint where the base metal and weld metal strength is a minimum of 70 Ksi) has periodically been discussed with my code peers.

My thought on this is from a mechanical property view point and design of the weld joint, the bulk strength will not be adversely affected by using slightly lower strength weld metal at the weld root region because the membrane stresses will act over the through thickness of the weld region and the bulk stregnth properties will prevail.


For fracture toughness, this is not the case because now you have low service temperature. In your situation, if you need to use the 6010 to pull open butt weld roots, than I would qualify the weld procedure with impact testing to determine the specific effect of using 6010 that is qualified for use only down to -29 deg C.