Microstructure and mechanical properties of weld metal in laser and gas metal arc hybrid welding of 440-MPa-grade high-strength steel  

作　　者：Fu-xing Yin Xu-chen Li Cui-xin Chen Lin Zhao Yun Peng Zhi-ling Tian 

机构地区：[1]School of Materials Science and Engineering,Hebei University of Technology,Tianjin 300130,China [2]Tianjin Key Laboratory of Laminating Fabrication and Interface Control Technology for Advanced Materials,Hebei University of Technology,Tianjin 300130,China [3]Research Institute for Energy Equipment Materials,Hebei University of Technology,Tianjin 300130,China [4]Central Iron and Steel Research Institute,Beijing 100081,China

出　　处：《Journal of Iron and Steel Research International》2021年第7期853-861,共9页

基　　金：National Key R&D program of China(No.2018YFB1107900);the Equipment Pre-research Project of China(No.41422010105).

摘　　要：Fiber laser and gas metal arc hybrid welding of 440-MPa-grade high-strength marine steel was carried out at different welding speeds.The influence of welding speed on the micro structure and mechanical properties of weld metal was investigated.The weld-metal microstructure mainly consisted of pre-eutectoid ferrite,side-plate ferrite,acicular ferrite and lath bainite at a low welding speed.With the increase in welding speed,acicular ferrite and lath bainite were the dominant weld-metal microstructures.All samples failed at the base metal during tensile tests,which indicates that there is no soft zone in the hybrid welds.The welding speed had a significant effect on the impact toughness of the weld metal.The impact absorbed energy of the weld metal increased from 35 to 105 J with the increase in welding speed from 0.8 to 2.0 m/min.Large amounts of acicular ferrite and lath bainite were formed in the weld metal at a high welding speed,which resulted in an excellent impact toughness.

关 键 词：Laser-arc hybrid welding High-strength steel Microstructure Mechanical property 

分 类 号：TG456.6[金属学及工艺—焊接]