【摘要】 磁控等离子-药芯焊丝电弧复合焊（plasma-flux cored arc welding,Plasma-FCAW）作为一种高效的复合电弧焊接方法，具有深熔性好、飞溅小等优势，但由于水下环境复杂，焊接过程易受干扰，为此，本研究采用自主设计的励磁装置对Plasma-FCAW复合水下焊施加横向磁场进行调控，促进两电弧间的柔性耦合，有效改善复合焊接过程及焊缝成形的稳定性。在此基础上进行不同盐度、温度水环境下的焊接工艺实验，并研究了水环境对熔滴过渡行为及焊缝成形和组织性能的影响。结果表明，盐度提高会使熔滴过渡周期缩短、冷却速度提高、焊缝熔宽下降，水温对电弧稳定性和熔滴过渡行为影响显著，低温下熔滴过渡周期缩短，高温时熔滴过渡周期不规则。盐度增加和水温降低都会导致焊缝区侧板条铁素体和针状铁素体含量提高，而水温升高会使热影响区珠光体含量有所增加，从而对焊缝硬度产生影响。更多还原

【Abstract】 Magnetically controlled plasma-flux cored arc welding(Plasma-FCAW), as an efficient hybrid arc welding method, is characterized by excellent deep penetration and low spatter. However, the welding process is susceptible to disturbances due to the complex underwater environment. To address this issue, a self-developed electromagnetic excitation device was used in this study to apply a transverse magnetic field to the underwater hybrid Plasma-FCAW process. This magnetic control facilitated flexible coupling between the two arcs, thereby effectively improving the stability of the hybrid welding process and the weld bead formation. On this basis, welding process experiments were carried out in water environment with different salinities and temperatures. The influence of the water condition on droplet transfer behavior, weld formation, as well as microstructure and properties was studied. The results show that increased salinity shortens the droplet transfer cycle, raises the cooling rate, and reduces the weld width. Water temperature significantly affects arc stability and droplet transfer behavior: the droplet transfer cycle shortens at low temperature, while it becomes irregular at high temperature. Both increased salinity and decreased water temperature increase the content of side-plate ferrite and acicular ferrite in the weld zone. In contrast, higher water temperature increases the pearlite content in the heataffected zone, thereby affecting the hardness of weld.更多还原