This is not a response to your exact question but may still be of value. Many major pipeline operators have adopted the use of E6010 root + E8010 fill and cap for grades up to and including X65. We even have a qualified procedure using it for X70. The E6010 gives excellent root weldability while the E8010 provides the strength needed for the high strength pipe. The E6010+E8010 combination results in a useful procedure for almost everything (close to the proverbial one-size-fits-all procedure for pipe) and eliminates potential confusion related to mixing up welding procedures on different grades (as long as the welder remembers to switch to E8010 after the root).

You can run beads with any lincoln 7010, and it's done, but only rarely. None of them will be as welder friendly as 5P+ beads.

Like Bill A said, 5P+(6010) bead, 70+(8010) fill & cap is the standard of the industry on that grade pipe.

JTMcC.

Hi ajoy:

We have invariably used E 6010 for root runs on piping ( backchipping not possible ) followed by E 7018. In a recent job, the client wanted root with 7010 for Gr 60 material and our welders had difficulties in qualifying. Ultimately based on similar logic that 6010 gives excellent penetration and subsequent capping with 7018 gives desired strength, we could proceed with 6010.

Others have suggested E 6010 + 7010 or 8010 combination. I am not used to it. Besides aren't 7010 or 8010 rods more expensive than 7018 or 8018 ?

Incidently, it may interest you that we have used E 11018 electrodes for welding of 55 mm thk. 3000mm dia penstock piping near Bombay. I dont now remeber the welding parameters like preheat and PWHT.
Prakash