1. Rough Cutting Surface with Poor Perpendicularity
Problem Manifestation
The cut metal surface exhibits jagged patterns, residual burrs, or the cutting plane is not perpendicular to the plate, resulting in insufficient workpiece accuracy.
Causes
Deviation in Laser Focus Position: The focus is too high or too low, preventing precise energy application to the cutting area.
Mismatch Between Cutting Speed and Power: Excessive speed causes slag to fail to discharge in time, while too slow speed leads to over-melting.
Abnormal Auxiliary Gas Pressure: Inadequate pressure or unstable airflow fails to effectively blow away slag.
Solutions
Calibrate the Focus Position: Use a focus tester or trial cutting to adjust the focus to the optimal position (typically at or inside the plate surface).
Optimize Parameter Combination: Determine the best speed-power ratio through experiments based on material and thickness (e.g., 1mm stainless steel: 1000W power, 8-10m/min speed).
Inspect the Gas System: Ensure sufficient cylinder pressure, clean the gas pipeline, and replace clogged gas filters.
2. Slag Adhesion on the Cutting Surface
Problem Manifestation
Slag remains at the bottom of the plate after cutting, requiring secondary grinding and increasing costs and man-hours.
Causes
Low Purity of Auxiliary Gas: Moisture or impurities in the gas affect slag removal.
Inadequate Laser Power: Inability to fully melt thick plates, causing slag adhesion.
Worn Cutting Nozzle: Enlarged or deformed nozzle aperture leads to divergent airflow.
Solutions
Replace with High-Purity Gas: Use nitrogen or oxygen with purity ≥99.99%, and regularly check gas purity test reports.
Increase Power or Reduce Speed: For thick plates (e.g., 10mm carbon steel), appropriately increase power to over 3000W or reduce speed below 2m/min.
Replace the Nozzle: Select a nozzle model matching the equipment, inspect wear regularly, and replace every 200 hours.
3. Cutting Accuracy Deviation
Problem Manifestation
Cutting dimensions do not match design drawings, or the cutting path shifts, leading to batch defects.
Causes
Wear of Mechanical Components: Clearance or deformation in guide rails and lead screws due to long-term use.
Software Parameter Errors: Incorrect settings for material compensation values or cutting path algorithms in programming software.
Laser Optical Path Deviation: Displacement of mirrors or focusing lenses causes beam direction errors.
Solutions
Mechanical Calibration: Use a dial indicator to check guide rail straightness, replace worn components, and ensure transmission accuracy ≤±0.03mm.
Review Software Parameters: Verify material thickness compensation values (e.g., 0.05mm compensation for 0.1mm plates) and update to the latest cutting software version.
Optical Path Calibration: Adjust the optical path using a cross cursor or trial cutting to ensure the laser beam is perpendicular to the cutting surface.
4. Difficulty in Cutting Perforation
Problem Manifestation
Failure to penetrate the material or excessive time required for initial perforation on the plate.
Causes
Improper Perforation Parameters: Insufficient perforation power, frequency, or time settings.
Thick Oxide Layer on Material Surface: Rust or scale hinders laser energy absorption.
Excessive Nozzle-to-Plate Distance: Dispersed airflow fails to concentrate on slag removal.
Solutions
Optimize Perforation Parameters: Increase perforation power to 1.5-2 times the cutting power and extend perforation time to 2-3 seconds.
Preprocess Materials: Sand or blast rusted plates to enhance laser absorption.
Adjust Nozzle Height: Maintain a nozzle-to-plate distance of 0.5-1.5mm to ensure concentrated airflow.
5. Frequent Equipment Alarms and Shutdowns
Problem Manifestation
Abnormalities such as overheating, insufficient air pressure, or software errors interrupt production during machine operation.
Causes
Cooling System Failure: Insufficient coolant, clogged water pump, or dust accumulation in radiators.
Electrical System Anomalies: Loose wiring, aged contactors, or PLC program errors.
Sensor Malfunction: False alarms from limit sensors or temperature sensors.
Solutions
Maintain the Cooling System: Replace coolant regularly (every 6 months), clean radiator dust, and check water pump flow rate.
Troubleshoot Electrical Issues: Tighten terminal connections, replace aged components, and redownload or debug PLC programs.
Calibrate Sensors: Test sensor sensitivity with standard tools and repair or replace faulty components.
6. Deformation of Thin Plate Cutting
Problem Manifestation
Thin metal plates (e.g., ≤1mm) warp or develop wavy deformations due to thermal stress during cutting.
Causes
Excessive Laser Energy: Concentrated local heat causes material overheating and deformation.
Lack of Support Devices: 悬空切割 (suspended cutting) without fixed constraints.
Solutions
Reduce Power and Optimize Cutting Path: Use pulsed laser mode to reduce single-energy output; prioritize cutting short edges or adopt jump-cutting to disperse heat.
Install Support Structures: Lay grid-shaped support bars under the plate or use a vacuum adsorption platform to secure the material.
Conclusion
The stability of metal laser cutting relies on equipment maintenance, parameter optimization, and standardized operation. By systematically troubleshooting common issues (e.g., slag adhesion, accuracy deviation) and adjusting key parameters such as focus position and gas pressure, cutting quality and production efficiency can be significantly improved. Enterprises are advised to establish regular equipment maintenance systems and dynamically optimize processes based on material characteristics to achieve efficient and stable metal processing.