以16 mm厚低合金高强钢11CrNi3MnMoV为实验材料, 研究了不同能量输入模式下厚板激光填丝多层焊的焊接工艺特性。设计了窄间隙坡口形式, 实现了双光束激光填丝的单道多层焊。通过对比单、双光束填丝焊的焊缝成形特征, 确定气孔、未熔合为高强钢厚板激光多层焊的主要缺陷, 双光束可有效提高焊接稳定性、降低焊缝气孔, 同时明显提高焊丝对中性能; 辅助层间保温与热丝技术可有效解决未熔合与层间束腰过小问题。双光束热丝焊的接头抗拉强度可达母材97％以上, 为填丝多层焊的优选工艺。焊缝断口呈现为韧窝型剪切断裂。

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.