Advantages of argon and carbon dioxide mixture in the welding process

Generally, the commonly used mixture of carbon dioxide and argon is used as welding shielding gas at a ratio of two to eight, so that it can be well protected during welding. Like this kind of carbon dioxide and argon mixed in a ratio of 2:8, we usually call it two-shield welding. It is widely used in welding. So what are the advantages of two-protection welding in welding?

1、Pure carbon dioxide is a gas heavier than air. It has high thermal conductivity, produces a wider arc, and has a wider weld seam. Carbon dioxide has strong oxidizing properties, and it produces larger splashes during welding. Argon is also a gas heavier than air. It can be used for welding to effectively protect the droplet and weld pool, improve the smoothness of the welding surface, and have less spatter, but the ionization arc produced by argon gas is narrow and the arc is unstable. Therefore, these two gases have their own advantages and disadvantages when they are used for welding alone.

The mixture of carbon dioxide and argon allows the advantages of the two gases to be fully utilized during welding while avoiding their respective disadvantages. The argon component improves the quality of the welding surface and reduces the splashing caused by carbon dioxide. The carbon dioxide composition enhances the stability of the arc and improves the heat conduction, thereby increasing the mechanical properties of the welding material. The mixture of argon and carbon dioxide is an ideal welding shielding gas.

2、The use of pure carbon dioxide welding is generally not easy to produce excessive spray. Because it makes the droplets produced by the welding wire larger during the welding process, it is subjected to an upward electromagnetic force when the droplets escape from the surface tension and fall into the welding pool. Due to the large droplets, the electromagnetic force is unbalanced. Acting on the molten droplets, in this way, a large number of molten droplets fall to the outside of the welding pool while falling, and a lot of splashes are generated. The mixed gas of argon and carbon dioxide can produce overspray, which makes the welding wire droplets become smaller and smaller. When the small droplets fall, the electromagnetic force acting on the droplets is much more balanced than the large droplets. The small molten droplets will transition to the molten pool, and the generation of splashes will be greatly reduced.The reduction of splashes makes the welding workers no longer need to stop often to clean the welding tip, and there is no need to use special workers to clean up the splash on the seam. , Mixed gas welding greatly improves the welding production efficiency. The use of argon and carbon dioxide mixed gas welding to reduce spatter is beyond the dust of pure carbon dioxide welding.