基于0.5 mm厚度Hastelloy C-276合金，开展了脉冲激光焊接实验。结合焊接熔池的浮力效应和Marangoni对流，研究了脉冲宽度、单脉冲能量、脉冲频率和焊接速度对焊缝形成规律的影响。实验表明，单脉冲能量和焊接速度对熔池流动机制的影响相似，适当的参数条件下可以改变Marangoni对流和浮力效应的强弱趋势；而脉冲宽度直接决定了对流机制的形成条件，对焊缝的形成影响显著；脉冲频率的改变决定了相对热作用时间，影响了熔池对流条件，进而影响焊缝形貌特征。

The pulsed laser welding experiment of Hastelloy C-276 of 0.5 mm thickness is conducted. According to buoyancy force and Marangoni convection, the influences of pulse duration, pulse energy, pulse repetition rate and welding velocity on weld joint are investigated. It is indicated that the pulse energy and welding velocity present the same impact on the forming of weld joint, and suitable parameters can affect the interaction between buoyancy effect and Marangoni convection. The pulse duration can decide the pool liquid flow, and further significantly impact the forming of weld joint. In addition, the variation of repetition rate determines the relative thermal action and impacts the pool flow, and finally varies the weld joint.