The magnetically constricted arc technique was implemented to mitigate the heat input related metallurgical problems in Gas Tungsten Arc Welding (GTAW) of Inconel 718 alloy particularly Nb segregation and subsequent laves phase evolution in fusion zone. This paper reports the direct effect of magnetically constricted arc traverse speed (MCATS) on bead profile, tensile properties and microstructural evolution of Inconel 718 alloy sheets joined by Gas Tungsten Constricted Arc Welding (GTCAW) process. The mechanism amenable for the microstructural modification and corresponding influence on the tensile properties of joints is investigated both in qualitative and quantitative manner related to the mechanics of arc constriction and pulsing. It is correlated to the solidification conditions during welding. The relationship between MCATS and Arc Constriction Current (ACC) was derived. Its interaction effect on the magnetic arc constriction and joint performance was analysed. Results showed that the joints fabricated using CATS of 70 mm/min exhibited superior tensile properties (98.39% of base metal strength with 31.50% elongation). It is attributed to the grain refinement in fusion zone microstructure leading to the evolution of finer, discrete laves phase in interdendritic areas.

实施磁收缩电弧技术以减轻 Inconel 718 合金钨极电弧焊 (GTAW) 中与热输入相关的冶金问题，特别是 Nb 偏析和熔合区随后的熔岩相演变。本文报告了磁收缩电弧移动速度 (MCATS) 对通过气体钨收缩电弧焊 (GTCAW) 工艺连接的 Inconel 718 合金板的焊缝轮廓、拉伸性能和微观结构演变的直接影响。以定性和定量的方式研究了与电弧收缩和脉冲力学相关的微观结构改性机制和对接头拉伸性能的相应影响。它与焊接过程中的凝固条件有关。导出了 MCATS 和电弧收缩电流 (ACC) 之间的关系。分析了其对磁弧收缩和接头性能的交互作用。结果表明，使用 70 mm/min 的 CATS 制造的接头表现出优异的拉伸性能（98.39% 的母材强度和 31.50% 的伸长率）。这归因于熔合区微观结构中的晶粒细化导致在枝晶间区域中演化出更细的、离散的 laves 相。