When using a handheld laser welding machine, the selection of shielding gas directly affects weld formation quality and the service life of the equipment.
Commonly used shielding gases include nitrogen, argon, carbon dioxide, and mixed gases. Different gases may produce different results depending on the material being welded and the specific application requirements.
Can Handheld Laser Welding Machines Use Air for Welding?
In recent years, some discussions in the market have suggested that laser welding can be performed directly using air as a shielding gas.
In reality, air welding can achieve a certain welding effect, but it is generally not recommended for products that require high weld quality.
During laser welding, shielding gases are usually inert gases. Their purpose is not only to protect the weld seam but also to protect the protective lens inside the welding head.
Two Main Functions of Shielding Gas
1. Prevent Weld Oxidation
During laser welding, the molten metal area reaches a high temperature and can easily react with oxygen in the air.
Shielding gas isolates the welding area from oxygen, reducing weld oxidation and helping achieve better weld appearance and more stable forming quality.
2. Protect the Laser Protective Lens
During handheld laser welding, spatter, smoke, and metal particles are generated.
Without continuous shielding gas flow, these contaminants can enter the welding head and contaminate the protective lens, affecting laser output and potentially preventing the laser from operating properly.
Which Is Better: Nitrogen or Argon?
Based on practical welding experience, nitrogen and argon provide similar welding performance in most applications.
For example:
When welding stainless steel, both gases can achieve good welding results.
When welding aluminum, the gas selection may vary depending on specific process requirements.
In actual applications, users can choose according to local gas availability and operating costs. The more convenient and economical option is usually preferred.
Why Is Air Welding Not Recommended?
Air contains oxygen, and oxygen promotes metal oxidation.
Welding Stainless Steel
If the weld bead is required to maintain a good appearance, such as golden or silver-white colors, it is difficult to achieve the desired result when using air welding.
Due to oxidation, the weld bead may become black, yellow, or discolored.
Welding Carbon Steel
Carbon steel naturally has a darker surface appearance, so weld color requirements are relatively lower. However, using air welding may lead to:
Increased weld porosity
More internal defects
Unstable welding quality
Therefore, in normal industrial production, air is generally not recommended as a shielding gas unless the product has no special requirements for welding quality.
Conclusion
For handheld laser welding machines, nitrogen or argon is recommended as the shielding gas. Both gases can meet the requirements of most welding applications.
The choice of shielding gas mainly depends on:
Type of welding material
Weld appearance requirements
Local gas supply availability
Operating cost
Proper selection of shielding gas, combined with suitable laser parameters, is essential for achieving high-quality laser welding results and improving equipment stability.
