| Abstract Scope |
Due to changes in how pipe mills manufacture pipe steel, the pipeline industry saw an increase in strength of new steel. A pipe steel classified to API 5L X70, which requires a 70ksi yield strength, will often have a yield strength of 80ksi or more. Traditionally, the root pass of a girth weld is welded with an E6010 electrode per AWS A5.1 (e.g. FleetweldŽ 5P+). However, because of the higher strength seen in a new pipe construction, pipeline companies are requesting higher strength consumables for the root pass. The electrodes qualified as E8010-P1 per AWS A5.5 (e.g. PipelinerŽ 8P+, PipelinerŽ Arc 80) were specifically designed for the fill and cap passes of a girth weld. Hence, they tend to have a “softer” arc and less fluid puddle that makes welding higher up in the groove, where there is a higher chance of spillage, more comfortable for the operator. Due to these attributes, they are not ideal for root pass applications where the arc needs to be strong enough to punch through the gap but also fill up the keyhole to provide backbead reinforcement. Therefore, Lincoln Electric developed a new SMAW electrode that meets E8010-P1 requirements per AWS A5.5, while providing the operability of the extensively used FleetweldŽ 5P+. This new product, PipelinerŽ 80R, provides good arc force and a slightly more fluid puddle that punches through tight fit-up while filling in the root, reducing internal undercut and providing sufficient reinforcement on the backbead. |