A computational investigation of different helium supplying methods for the improvement of GTA welding
A computational investigation of different helium supplying methods for the improvement of GTA welding
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DOI：
10.1016/j.jmatprotec.2011.04.008
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发表时间：
2011-09
影响因子：
6.3
通讯作者：
A. Traidia;F. Roger
中科院分区：
文献类型：
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作者：
A. Traidia;F. Roger
为了研究氦添加对熔池性能的影响，建立了熔池和电弧的瞬变模型。研究了Ar-He混合气体供应，以及纯Ar和纯氦交替供应，发现电弧特性高度依赖于保护气体的组成。氦的加入增加了熔池中的主要控制力，尤其是电磁力。这会导致熔池中出现电磁诱导的涡流，从而导致焊缝熔深增加3倍以上。数值预测与实验宏观图的比较表明，形状和尺寸都很好地符合。数值结果揭示了交替供应保护气体的两个主要优点；与传统的混合气体供应相比，替代方法更节省成本，并且在同等焊缝熔深的情况下减少了对工件的换热。
A transient arc and weld pool model is developed, to study the effect of helium addition on the weld pool properties. Supplying mixtures of argon–helium, and alternate supply of pure argon and pure helium, are both studied.The arc characteristics are found to be highly dependent on the shielding gas composition. The addition of helium to argon increases the main governing forces in the weld pool, and more particularly the electromagnetic forces. This leads to the appearing of an electromagnetically induced vortex in the molten pool, which itself leads to an increase in the weld penetration by a factor that goes up to 3. The comparison between the numerical predictions and the experimental macrographs shows a good agreement as well as shape as dimensions.The numerical results reveal two main advantages of alternate supply of shielding gases; compared to the conventional mixtures supplying, the alternate method is more cost saving, and reduces the heat transfer to the workpiece for an equivalent weld penetration.