Prequalified Procedure SMAW 6010/7018

Date 07-16-2009 02:55

Not if you intend to make a weld from one side without backing. There are no prequalified complete joint penetration details for a single-sided groove weld without backing.

If you want to use a prequalified joint detail with a combination of E6010 and E7018, it will be limited to the lower strength Group I base metals in Table 3.1, since those are the only prequalified base metals that permit use of E60XX electrodes.

By hpsamm Date 07-16-2009 16:08

Thanks, actually it is intended for an A-36 carbon steel and I can see in Table 3.1, will be limited to a thickness less or equal to 3/4".
My doubt was mainly about the 6010/7018 combination.

Thanks for your comments

Regards

By 803056

Date 07-16-2009 22:29

What is the material specification, thickness, etc.?

As for the intermixing of E6010 with 7018, that isn't unusual if the material is compatible with both, the material thickness is limited, if the lower strength filler metal is appropriate for the base metal, if the proper preheat is used, etc.

Al

By hpsamm Date 07-16-2009 23:49

it is an ASTM A-36, thickness is 1/2"

thanks for your comments!

Regards

By 803056

Date 07-17-2009 16:12

ASTM A36 can be welded with E6010 as long as the preheat is in accordance with Table 3.2 for the thickness being welded. Likewise, E7018 can be used as well, but the preheat requirements are somewhat lower for a given thickness when compared to the E6010. For the thickness you mentioned, i.e., 1/2 inch, the preheat requirements are the same for both E6010 and E7018.

You still have to comply with the storage requirements of the code for the low hydrogen electrodes.

I assume you do not have to meet toughness requirements. If you do, check A5.1 to verify both electrodes can meet the toughness requirements at the temperature specified by the Engineer. If my memory serves me correctly, with toughness requirements imposed, you will have to qualify the WPS considering all the essential variables of Clause 4, including the supplementary variables for notch toughness.

Best regards - Al

By hpsamm Date 07-17-2009 16:45

Thanks Al

Regards

By swnorris (****)

Date 07-20-2009 19:14

Watch your contract verbiage. With structural steel, the typical electrode requirement is E70xx.

By 803056

Date 07-22-2009 04:20

Hello SW;

The question was specific to E6010 and E7018.

You do make a point that I would like to expand upon.

There are Engineers out there that assume any SMAW electrode that meets E70XX by nature meets the requirements for low hydrogen, i.e., they produce no more than 16 ml of diffusible H per 100 grams of weld deposit. CWIs in contrast should know that isn't the case. Likewise many people assume all FCAW electrodes produce welds that meet low hydrogen requirements. That isn't always the case. There are FCAW marketed that introduce considerable amounts of hydrogen into the weld puddle.

When the WPS specifies E70XX for welding a base metal that require a low hydrogen electrode, ASTM A992 for instance, the CWI should request the WPS be revised to only list low hydrogen electrodes.

Best regards - Al