TY - CONF A1 - Rethmeier, Michael A1 - Gook, S. A1 - Gumenyuk, Andrey T1 - Laser-GMA-hybrid welding of longitudinally welded large-diameter pipes of grades API- X80/ X120 N2 - Potentials of the hybrid laser arc welding processes were investigated regarding reliable production of longitudinal welds of high strength pipe steels X80 and X120 Hybrid laser arc welding of the root pass: Significant reduction in the weld cross section – savings of filler material Lower heat input into the base material - improvement of mechanical properties of the weld joint  The arc type does not have any influence on the character of dilution in the laser part of the hybrid weld  14 mm deep root face was considered as optimum. No penetration of the filler material could be detected beyond this depth limit Metal powder filler wires, micro alloyed with Ni and partly with Cr and Mo, guaranteed sufficient Charpy impact toughness at low temperature for the both investigated materials: Hybrid laser arc welding is a very efficient process for the root pass in multi-pass welding and opens a large technical and economic potential for the manufacture of large pipes T2 - The METEC and 2nd European Steel Technology and Application Days (ESTAD)conference CY - Düsseldorf, Germany DA - 15.06.2015 KW - High power laser KW - Hybrid laser arc welding KW - Weld specimens KW - Charpy V-notch tests KW - Tensile tests PY - 2015 AN - OPUS4-38342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -