美国犹他州伯林哈姆扬大学的研究员们发现,对低碳钢进行熔化极气体保护焊时,最佳的保护气体为80CO_2+20He。他们使用 ER70S—3焊丝,多种保护气体如 Ar 气、He 气、CO_2气及其混合而成的气体,对低碳钢进行了一系列焊接试验。对于污染和飞溅的数量、焊缝表面粗糙度、焊道形状,熔深、成本以及全部性能作了测定和评价,结论为:所有的保护气均能有效地防止焊缝污染。预先混合的98Ar—CO_2保护气体产生的飞溅最少。产生的飞溅量与混合气体中 CO_2的百分数成正比。将氦气混入 Researchers at the University of Hanyang in Utah, Utah, have found that the optimum shielding gas for MIG welding is 80CO_2 + 20He. They used a series of welding tests on mild steel using ER70S-3 wire, a variety of shielding gases such as Ar, He, CO 2 and their blends. The number of pollution and spatter, weld surface roughness, weld bead shape, penetration, cost and overall performance were measured and evaluated. The conclusion is that all the protective gas can effectively prevent weld contamination. Pre-mixed 98Ar-CO 2 shielding gas produces the least amount of spatter. The amount of spatter produced is proportional to the percentage of CO 2 in the mixture. Mix helium