1. Match laser cutting speed to plate thickness
Cutting speed directly affects heat input and slag removal. An excessively fast speed leads to incomplete penetration and jagged cutting edges. If the speed is too slow, excessive heat accumulates and generates massive molten metal, which exceeds the slag-blowing capacity of auxiliary gas and forms thick, hard dross. Each material and thickness has its own optimal speed range. Perform repeated trial cuts and inspect the bottom cutting edges to confirm the ideal cutting speed.
2. Set proper laser output power
Laser power must match the thickness of processed plates. Insufficient power results in incomplete metal melting and discontinuous cuts; excessive power creates excessive molten material and severe spatter. Start with the parameter recommended by the machine manufacturer, then fine-tune the power within a ±5% range to improve edge quality. Meanwhile, the output power should not exceed 95% of the rated power of the cutting power supply, which prevents accelerated wear of consumables and extra production costs.
3. Recalibrate the laser focus
The laser focus determines where beam energy is most concentrated. Any offset of the focus widens the cutting kerf and drastically reduces slag removal efficiency. Process reference: set the focus slightly below the plate surface (negative focus) for carbon steel cutting; align the focus on or slightly above the surface for stainless steel. Adjust the focus by 0.5 mm each time and observe the slag condition at the bottom to lock in the optimal focus parameter.
4. Precisely adjust the pressure and purity of auxiliary gas
Auxiliary gas serves two core purposes: boosting exothermic reaction and sweeping away molten slag. Gas selection standard: oxygen for carbon steel, nitrogen or filtered dry compressed air for stainless steel. Low gas pressure leaves residual slag, while overly high pressure causes turbulent airflow and weakens slag-blowing performance. Stable pressure, rather than maximum pressure, should be prioritized during cutting. Strictly control gas purity: oxygen ≥ 99.5%, nitrogen ≥ 99.9%. Water and oil contaminants in gas will contaminate optical components and indirectly trigger burr defects.
5. Maintain a stable nozzle height to avoid operational fluctuations
The gap between the nozzle and the workpiece directly impacts the impact force of blowing gas. An overly large gap weakens slag-blowing force; an overly narrow gap disturbs airflow and causes reverse splashing of molten slag. The standard optimal height for fiber laser machines ranges from 1.0 mm to 1.5 mm. Turn on the capacitive torch height controller to stabilize the height in real time throughout cutting and avoid burrs caused by height fluctuations.
6. Replace worn consumables in a timely manner
Deformed or carbon-deposited nozzles disrupt airflow and lead to uneven slag removal. Contaminated protective windows absorb and scatter laser beams, lowering effective output power. Inspect nozzles daily for deformed openings, cracks and carbon buildup. Clean or replace protective windows immediately once fogging, burn marks or scratches appear. Replacing low-cost consumables is the most efficient and cost-effective way to get rid of burrs.
7. Keep all optical components clean
Dust and cutting spatter attached to reflectors, focusing lenses and protective windows degrade beam quality and shift the laser focus. Add optical component cleaning to the pre-start inspection checklist, and wipe components with special solvent and dust-free non-woven cloth. A clean optical path guarantees a stable laser beam and smooth cutting edges.
8. Adjust process parameters as an interconnected system
A common workshop mistake is adjusting only one single parameter. Laser power, cutting speed, focus position, gas pressure and nozzle height are all interrelated. For instance, raising cutting speed requires minor adjustments to power or gas pressure to maintain balanced cutting conditions. Never adjust parameters separately to fix burrs. Follow the standardized workflow: adjust one parameter, conduct a trial cut, then fine-tune related parameters to restore balance.
Conclusion
Burrs are a solvable process issue instead of an inherent flaw of laser cutting. Systematic inspection of the eight points above helps quickly locate root causes, eliminates post-polishing procedures, and delivers finished parts with smooth edges ready for direct assembly. Prioritize three high-frequency troubleshooting factors: cutting speed, focus calibration and worn consumables. File all optimized parameters for reuse in mass production once ideal cutting results are achieved.