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
Microstructure and mechanical properties of weld metal in laser and gas metal arc hybrid welding of 440-MPa-grade high-strength steel
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
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 microstructure 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.
Abstract：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 microstructure 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.
Fu-xing Yin,Xu-chen Li,Cui-xin Chen, et al. Microstructure and mechanical properties of weld metal in laser and gas metal arc hybrid welding of 440-MPa-grade high-strength steel[J]. Journal of Iron and Steel Research International, 2021, 28(7): 853-861.
2021, Vol. 28 
