During laser welding, protection gases such as Argon, Helium, and Nitrogen are often used to protect the molten pool to protect the workpiece from oxidation during the welding process.

1.Helium Gas:

It will not affect the transmission of the laser beam, can make the laser beam pass smoothly, and the energy of the beam can directly touch the surface of the workpiece without hindrance, and has a strong anti-oxidation effect. Helium is a more effective shielding gas for laser welding. However, the cost of using helium is relatively high.

2.Argon Gas:

Its density is relatively high, and the protection effect is better. When welding the workpiece, the surface of the workpiece is smoother than welding under helium welding, but argon is easily ionized by high-temperature metal plasma, which will shield part of the laser beam which shoots at the workpiece, reduces the effective power of welding, and affect the speed and penetration depth of welding to a certain extent, but the cost of argon gas is in the middle.

3.Nitrogen Gas:

For Nitrogen Gas, there are certain limitations in the welding process, and it is not suitable for all laser welding processes. For some types of stainless steel welding, it is not suitable. The reason is mainly due to metallurgical problems, such as absorption, sometimes Gas is generated in the lap area, but nitrogen is the cheapest to use.

4.Usually, different shielding gases are selected according to different metals.

Pls. refer to following application:

Aluminum and aluminum alloy: N2 or Ar2

Stainless steel: Ar2

Carbon steel: C02

Galvanized sheet: Ar2.