With the increasing use of thermomechanically processed steels for pipelines, the alloy content of each steel grade decreases from year to year. Using welding processes which result in high dilution of the weld metal by parent material, such as conventional submerged arc welding, it becomes increasingly difficult to achieve the very high weld metal yield strength demanded when welding X80 and X100 steels, especially when strain-based design is used. For X80 steels, submerged arc welding with tubular wires and with twin arcs can allow high productivity to be maintained while limiting the heat input and dilution, and satisfactory results produced by this route are presented. Special boron-containing wires can also be used where high dilution cannot be avoided. For X100 steels, the use of gas metal arc welding with a fixed welding head and a rotating pipe, combined with a narrow bevel preparation, allows excellent mechanical properties to be achieved without excessively high alloy contents in the welding wire. Because of the small joint volume, productivity need not be unduly lower than that of submerged arc welding. Substitution of metal-cored tubular wire for solid wire can give a further increase in productivity.
Double jointing of high strength pipelines
Welding in the World ; 54 , 11/12 ; 360-365
2010
6 Seiten, 6 Tabellen, 5 Quellen
Article (Journal)
English
Engineering Index Backfile | 1922
|Emerald Group Publishing | 1944
|Engineering Index Backfile | 1915