Abstract A novel, new approach of electromagnetic assisted wire wobbling to regulate energy allocation, melt flow and metallurgical structure is introduced in laser narrow gap welding of 316 L stainless steel. The formation of melt pool, weld surface morphologies and microstructure features in conventional laser welding, laser wobble welding and electromagnetic assisted wire wobble welding were compared. The results reveal that the forced convection generated by electromagnetic swing wire could broaden the melt pool size and compulsively push high-temperature weld metal towards groove sidewall. The wetting of liquid weld metal on groove sidewall was improved and concave weld morphology was obtained, thereby avoiding incomplete fusion of sidewall and favoring the filling of next weld bead. The temperature and element distribution in weld zone would be more uniform by the periodically and drastically forced convection, which helped to inhibit the growth of columnar crystals and promote the uniform distribution of elements. The average microhardness value in weld zone was uniform with the using of electromagnetic swing wire. Moreover, mechanisms of enhanced sidewall wetting and grain refinement were discussed in electromagnetic assisted wire wobble laser welding.

中文翻译：

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一种利用电磁辅助摆线调节窄间隙激光焊接中能量分配和熔体流动的新方法

摘要 在 316 L 不锈钢的激光窄间隙焊接中引入了一种新颖的电磁辅助焊丝摆动方法来调节能量分配、熔体流动和冶金结构。比较了传统激光焊接、激光摆焊和电磁辅助摆焊的熔池形成、焊缝表面形貌和显微组织特征。结果表明，电磁摆线产生的强制对流可以扩大熔池尺寸，并将高温焊缝金属强制推向坡口侧壁。改善了液态焊缝金属对坡口侧壁的润湿，获得了凹形焊缝形态，从而避免了侧壁不完全熔合，有利于下道焊道的填充。周期性强烈强制对流使焊缝区温度和元素分布更加均匀，有助于抑制柱状晶的生长，促进元素的均匀分布。使用电磁摆线后，焊缝区平均显微硬度值均匀。此外，还讨论了在电磁辅助摆线激光焊接中增强侧壁润湿和晶粒细化的机制。