Precautions for Laser Cutting Stainless Steel
When using a laser cutting machine to cut stainless steel, special attention must be paid to material properties, machine settings, and process optimization to ensure cutting quality, efficiency, and equipment longevity. Below are key considerations:
1. Characteristics of Stainless Steel
High Reflectivity: Stainless steel (especially polished/mirror surfaces) reflects laser light, which can damage the laser head or reduce efficiency.
High Melting Point & Viscosity: Stainless steel has a high melting point (~1400-1450°C), and its molten state is sticky, leading to **dross (slag) formation.
Oxidation Risk: Chromium oxide layers form at high temperatures, affecting cut-edge quality.
2. Machine & Parameter Settings
(1) Laser Type Selection
Fiber Laser (Recommended):
Wavelength (1070nm) is better absorbed by stainless steel.
Power recommendation: 1-3kW for thin sheets (1-3mm), 6kW+ for thick plates (8-20mm).
CO₂ Laser: Requires higher power (4kW+) and anti-reflective optics.
3. Process Optimization
Piercing Control:
Use gradual piercing (avoid explosive piercing).
Increase piercing time for thick plates (e.g., 0.5s for 3mm, 2-3s for 10mm).
Cutting Path Planning:
Avoid sharp turns; cut inner holes first to reduce thermal distortion.
Nozzle Selection:
1.5-3mm diameter (larger for thick plates).
4. Material & Auxiliary Measures
Sheet Preparation:
Clean oil/coatings (prevents lens contamination).
Apply protective film (reduces reflectivity).
Anti-Reflection Solutions:
Use anti-reflective laser heads or adjust beam angle.
For highly reflective SS (e.g., 304 mirror finish), roughen the surface first.
5. Safety & Maintenance
Safety Measures:
Wear laser-safe goggles (protects against reflections/sparks).
Ensure proper grounding (prevents electrostatic damage).
Machine Maintenance:
Regularly clean lenses, nozzles, and rails (stainless steel produces fine dust).
Check gas lines for leaks.
Conclusion
For optimal stainless steel laser cutting:
Use a fiber laser + nitrogen assist.
Optimize power, speed, and focus.
Combat reflectivity and slag with proper settings.
Maintain equipment and follow safety protocols.
For high-reflectivity stainless steel, always take anti-reflection measures to protect the laser system
----------Victor Feng
Rayther Laser