Wire filling laser multilayer welding of high strength steel thick plate

Characteristics of laser multilayer welding of 16-mm thick high strength steel 11CrNi3MnMoV with filler metal in different energy input modes are studied. A narrow gap groove is designed, and dual beam single pass multilayer laser welding with filler metal is carried out. By comparing the weld forming characteristics of single with dual beam laser welding with filler metal, porosity and incomplete fusion is regarded as the main defect of the joint. Moreover, the welding stability and alignment state of wire is obviously improved when the duel beam is used. At the same time, the welding defect, i. e. porosity, is impressed sharply. In addition, problems of incomplete fusion and narrow girdling are solved in the case of combining interbedded heat preservation and hot wire technology. As an optimized welding technology, the tensile strength of the joint processed by dual beam laser welding with hot wire can come up to 97% of matrix metal. Dimple shear fracture is the main failure mode at the fracture surface.