Laser Cutting Parameters for S355J2WP: Key Adjustments
When laser cutting S355J2WP weathering steel, parameter optimization is essential to maintain cut quality and HAZ (Heat-Affected Zone) corrosion resistance. Here are the critical adjustments and considerations:
1. Power & Speed Settings
| Thickness (mm) | Laser Power (W) | Cutting Speed (m/min) | Assist Gas | Pressure (Bar) |
|---|---|---|---|---|
| 1–3 | 1000–1500 | 4–6 | N₂ or O₂ | 8–12 (O₂), 12–15 (N₂) |
| 4–6 | 1500–2500 | 2–4 | O₂ (for clean cuts) | 10–14 |
| 6–12 | 2500–4000 | 1–2.5 | O₂ | 12–16 |
| 12–20 | 4000–6000 | 0.5–1.5 | O₂ + N₂ mix | 14–18 |
Notes:
O₂ produces cleaner edges but increases HAZ (0.2–0.5mm). Use for structural parts requiring weld prep.
N₂ reduces oxidation but requires higher power. Ideal for decorative finishes.
2. HAZ Control for Weathering Performance
Post-Cut Grinding: Remove 0.1–0.3mm from cut edges to restore patina-forming capability.
Heat Input Limit: Keep ≤ 20 kJ/cm to avoid Cr/Cu depletion in HAZ (critical for corrosion resistance).
3. Nozzle & Focus Adjustments
Nozzle Diameter: 1.2–2.0mm (thicker materials need larger nozzles).
Focal Position:
1/3 into material (e.g., +1mm focus for 6mm plate) to minimize dross.
4. Post-Processing for Corrosion Resistance
Deburring: Use ceramic abrasives (SiC) to avoid iron contamination.
Patina Restoration:
Spray edges with 5% CuSO₄ solution to accelerate protective rust formation.
For coastal applications, apply zinc-rich primer (50μm) on cut edges.
5. Quality Validation
ISO 9013 Class 2 tolerance: Check kerf width (≤0.2mm for <10mm thickness).
Microhardness Test: HAZ should be ≤350 HV10 (prevents brittleness).
