API 5L X70 welding filler metal

[fakhmed]

Dear All,

Can some body help me to determine the filler metal type to weld API 5L X70 pipe thickness 18mm with FCAW and SMAW process.

Thank you

 

[Goahead]

You may wish to consider that Ed Craig of

http://www.weldreality.com

in his page

http://www.weldreality.com/ASTM_API.htm

recommends
E7018
and
E71T-1

http://www.welding-advisers.com/

 

[GRoberts]

I would not use 70 tensile strength filler metal as X70 has a minimum tensile strenth of 82 ksi. You might achieve that based on what brand/type of consumable you use, but not probable.

I assume you are not going to PWHT. In that case, I would use either E81T1-K2 (more than 1% Ni, so make sure NACE requriements for sour service are not imposed), or 8018-C3.

 

[fakhmed]

Thank you but different type of electrodes.

Why not E8010G without PWHT?

 

[weldtek]

fakhmed,
As in most situations, there are numerous choices that will work. I've done as GRoberts has suggested and qualified a procedure using a low Ni electrode, but, Lincoln recommends among other things, 8018G. As to PWHT, you'll have to evaluate whether or not this is necessary based on other criteria.

 

[GRoberts]

8018-G really means nothing by itself. It just means it ia 80 minimum tensile strength, and of any chemistry. It could be a 12 Cr creep resistant electrode for all the 8018-G classification tells us. Each -G electrode has to be evaluated seperately with input from the manufacturer. There are literally tens if not hundereds of different kinds of -G electrodes out there, and they are all for different applications.

 

[fakhmed]

I've ordered already E81T1-K2M wire 1.2 and 1.6mm and we will proceed the welding with 80°C preheat and without PWHT for the pipe 1200mm diameter and 18mm thickness.

What is your opinion?

 

[GRoberts]

I've done X65 with that wire with PWHT, and still had plenty of strength. You should be fine with that combination.

 

[fakhmed]

Now the question is if the PWHT is necessary for such weld or not.

The API 5L is not so clear

Best regards

 

[SJones]

API 5L is the standard for manufacturing the pipe. Are you inquiring about seam welding in the shop, or girth welding in the field?

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[fakhmed]

This standard is required by our customer to manufacture from welded pipe some fittings (Elbow, Tee,...) Diameter 1200mm Thickness 18mm.