外加磁场下焊接技术的研究现状

Recent Progress in Welding Technology under External Magnetic Fields

近年来,磁控焊接技术受到了国内外研究人员的广泛重视。在焊接过程及焊后热处理过程中施加磁场,可以显著改善熔池金属的传质及传热行为,细化晶粒组织,减少成分偏析,促使第二相均匀化弥散分布,降低气孔、热裂纹等焊接缺陷的敏感性,显著提升焊缝力学性能。综述了国内外近年来磁控焊接技术的研究成果,对比了外加磁场与无磁场下焊接的特点,总结了Lorentz力、热电磁力、磁场力、磁Gibbs自由能对焊接过程的影响机制,以及磁场对焊缝微观组织、电弧形态、力学性能的影响规律。提出开发多尺度磁场下磁控复合焊接技术、磁控热处理技术结合焊接过程中电流场、温度场、应力场(应变场)有限元分析是将来磁控焊接技术的研究重点。

In recent years,magnetron welding technology has received extensive attention at home and abroad.The application of magnetic field in the process of welding and post-weld heat treatment can significantly improve the mass transfer and heat transfer behavior of molten pool metal,refine the microstructure,reduce segregation,promote the dispersed distribution of second phase,reduce the sensitivity of welding defects such as pore and crack,and thus significantly improve the mechanical properties of the weld zone.The influence mechanism of Lorentz force,magnetic field force,thermoelectric electromagnetic force,and magnetic Gibbs free energy on the welding process is summarized.At the same time,the influence rule of the magnetic field on microstructure,arc shape,and mechanical properties of the weld seam,and the corresponding principle are analyzed and discussed.It is pointed out that the development of multi-scale magnetic field,magnetron hybrid welding technology,magnetron heat treatment technology combined with finite element analysis of the current field,temperature field and stress field(strain field)in the welding process will be the research focus of magnetron welding technology in the future.