Girth Welding of X100 Pipeline Steels

Girth welding trials involving pipes of minimum proof strength 690 MPa (X100) from several linepipe manufacturers have been conducted. Welding consumable selections for the trials were based on background data generated at Cranfield University coupled with potential weld metal mechanical property requirements thought necessary for the implementation of X100 pipeline steels. Mechanised pulsed gas metal arc welding (PGMAW) and semi-automatic/ manual welding procedures were used to generate mechanical property data of mainline girth welds, tie-ins and repairs using equipment and procedures as close to current field practice as possible. The trials showed no detrimental weldability issues for the X100 steels examined. Testing comprised tensile, toughness (CVN and CTOD), hardness, side bend and nick break data generation, using pipeline welding specifications where possible.