Common Shielding Gases for Fiber Laser Welding Machines and Their Functions

In the laser welding process, shielding gas does not directly participate in welding, but it plays a crucial role in weld quality, seam formation, and equipment stability. Proper selection and use of shielding gas can effectively improve welding performance and reduce defect rates. This article introduces the common gases used in laser welding machines and explains their specific functions.

Why Shielding Gas Is Required in Laser Welding

Laser welding features high energy density and fast welding speed, causing the welding area temperature to rise sharply in a very short time. Without shielding gas, the molten pool can easily react with oxygen and nitrogen in the air, leading to oxidation, porosity, weld discoloration, and other defects. The main functions of shielding gas include:

Isolating air to prevent oxidation

Stabilizing the molten pool and improving weld quality

Reducing spatter and enhancing weld appearance

Protecting the laser welding head and optical lenses

Common Types of Gases Used in Laser Welding Machines and Their Functions

Argon (Ar)

Argon is one of the most widely used shielding gases in laser welding. It is chemically inert and does not easily react with metals.

Main functions:

Effectively isolates air and prevents weld oxidation

Improves weld formation, resulting in smooth and clean weld seams

Suitable for a wide range of materials such as stainless steel, carbon steel, and aluminum alloys

Nitrogen (N₂)

Nitrogen is relatively low-cost and can replace argon in certain welding applications.

Main functions:

Reduces oxidation and improves weld surface quality

Suitable for welding processes where appearance requirements are not extremely high

Commonly used for carbon steel and thin stainless steel welding

However, under high-temperature conditions, nitrogen may react with some metals, so it is not suitable for all materials.

Helium (He)

Helium has high ionization energy and excellent thermal conductivity, but it is relatively expensive.

Main functions:

Increases weld penetration and enhances welding stability

Suitable for high-reflectivity materials such as aluminum and copper

Helps achieve deeper and narrower weld seams

Mixed Gases

In practical production, mixed gases such as argon + helium or argon + nitrogen are often used according to material type and process requirements.

Main functions:

Combine the advantages of different gases to improve welding efficiency

Reduce gas costs while ensuring weld quality

Adapt to more complex welding conditions

Functions of Auxiliary Gas

In addition to shielding gas, auxiliary blowing gas may also be used during laser welding to:

Remove smoke and spatter generated during welding

Protect the welding head lenses and extend the service life of optical components

Improve equipment operating stability and safety

How to Choose the Appropriate Welding Gas

When selecting shielding gas, the following factors should be considered comprehensively:

Type of welding material

Welding thickness and process requirements

Weld appearance and strength requirements

Cost control and production efficiency

Only with proper gas selection and parameter configuration can the high-efficiency advantages of laser welding machines be fully realized.

Conclusion

Shielding gas is an essential part of the laser welding process that should not be overlooked. Scientific gas selection not only improves welding quality but also extends laser equipment service life. Xianming Laser welding machines support multiple gas configurations and are suitable for various materials and application scenarios, providing users with stable and efficient welding solutions.