Laser Welding Machine: How to Prevent Oxidation During Welding

Oxidation during laser welding—seen as discoloration, scale, or reduced corrosion resistance—is a common issue, especially with stainless steel, titanium, or aluminum. While a laser welding machine produces a clean, narrow weld, it still requires proper protection to avoid unwanted reactions with atmospheric oxygen.

Use Adequate Shielding Gas

The most effective way to prevent oxidation is consistent shielding gas coverage. Argon is preferred for most metals due to its density and inert properties; nitrogen can be used for certain stainless steels but may cause porosity in others. The key isn’t just gas type—it’s delivery method and flow stability.

A coaxial nozzle that surrounds the laser beam provides direct protection at the point of melt. For longer seams, add trailing shields that cover the cooling weld zone (up to 10–15 seconds post-weld), since metal remains reactive until it drops below ~400°C.

Optimize Gas Flow and Purity

Too low flow won’t displace air; too high can cause turbulence and draw in oxygen. Typical flow rates range from 10–20 L/min, but this depends on nozzle design and travel speed. Also, ensure gas purity is ≥99.995%—moisture or oxygen impurities in lower-grade gas will still cause discoloration.

Consider Chamber or Local Enclosures for Critical Parts

For aerospace or medical components, some users weld inside glove boxes or local vacuum chambers filled with argon. While not practical for all applications, even a simple acrylic enclosure around the weld zone can significantly reduce oxidation on sensitive parts.

Final Tip: Clean Before You Weld

Oil, grease, or oxide layers on the base material can decompose during welding and release oxygen. Always clean surfaces with isopropyl alcohol or appropriate solvents before welding.

In short, preventing oxidation with a laser welding machine isn’t about the laser itself—it’s about controlling the environment around the weld pool. Proper gas shielding, clean materials, and smart fixture design make all the difference.