Research on all-position laser-arc hybrid welding for long-distance transportation pipeline

Using laser-arc hybrid welding method to weld pipeline butt will improve the efficiency of pipeline construction.The feasibility of welding pipeline butt by laser-arc hybrid welding process was discussed through experiments.Experiment results showed that hybrid welding meet the requirements for girth welding.From 0 to 180 degree, by using different parameters union, the welding joint is satisfactory.Metallographic image showed the base material and welding material fused soundly, the cross section of welding seam was as narrow as that of the laser welding, and the heat affected zone was of the same characteristic of arc welding.Metallurgical structure is not affected by position variation.The hardness value and tensile strength of welding seam is close to or exceed that of the base material.The result of bending test and impact test are qualified in the case that there are no internal defects.