Submerged Arc Welding X100 Pipeline Steels

100 Pipeline Steels are welded by United States Lincoln double-wire welding machine. The welded joints have good weld formation and high welding quality, with no pore and crack inside. The tensile strength of the welded joint gets to 805MPa, about 94.71%of that of the parent metal. With the increase of heat input, the content of acicular ferrite is decreased in the weld zone, grains are greater in the heat-affected zone (HAZ), the strength and toughness ofx100 pipeline steel are lower. The absorbed energy and the shear area decrease with increasing heat input in weld zone.