Affecting Factors Of the Cutting Quality Of Fiber Laser Cutting Machine

Affecting Factors Of the Cutting Quality Of Fiber Laser Cutting Machine

1. Cutting Height

As shown in the figure below, if the distance between the nozzle and the workpiece is too short, it may cause the collision of the plate and the nozzle; if the distance is too long, it may cause gas diffusion, causing more residues on the cutting bottom.

The distance between the nozzle and the workpiece can be set at the “Technology” interface, and the recommended distance is between 0.5-1.5mm.

2. Cutting Speed

The speed of feeding can be judged from the cutting spark. Under the condition of normal cutting, the spark is diffused from top to bottom, and when the spark is tilted, the speed of feeding is too fast; if the spark is not diffused but condensed, the speed of feeding is too slow. The following figure shows the appropriate cutting speed, the cutting surface shows a smooth line, and no slag comes from the lower part.

In case of poor quality of cutting, it is recommended to carry out a general inspection first, of which the content and sequence are as follows:
1)Cutting height (it is recommended that the actual cutting height is between 0.5 and 1.5mm): If the actual cutting height is not accurate, the calibration should be carried out.

2)Nozzle: Check the type and size of the nozzle to see if it is used correctly. If it is correct, check whether the nozzle is damaged, and the roundness is normal.
3)It is recommended to conduct an optical center inspection of the nozzle with a diameter of 1.0, and the focus should be between -1 to 1 while inspecting the optical center. In this way, small light points are easy to be observed.
4)Protective lens: Check whether the lens is clean, and confirm there are no water, no oil and no slag on the lens.

Sometimes the protective lens may be fogged due to weather or too cold auxiliary gas.

5)Check whether the focus is set correctly.

6)Modify the cutting parameters.

After checking the above six items, if no problems, modify the parameters according to the phenomenon.

Structural steel: Cutting with O2
Defects	Possible Cause	Solutions
There is no burr, and the drawn wire is consistent.	Power is proper   The cutting speed is proper
The drawn wire at the bottom has a large deflection and the bottom kerf is wider.	The cutting speed is too high Cutting power is too lowAir pressure is too low   The focus is too high	Reduce the cutting speedIncrease cutting power Increase air pressure Lower the focus
Burrs at the bottom surface are similar to slag, and like droplet and easy to remove.	The cutting speed is too high Air pressure is too low The focus is too high	Reduce the cutting speed Increase air pressure Lower the focus
Connected metal burrs can be removed as a whole piece.	The focus is too high	Lower the focus

Metal burrs at the bottom surface are difficult to remove.	The cutting speed is too highAir pressure is too low Gas is not pure The focus is too high	Reduce the cutting speedIncrease air pressure Use pure gas Lower the focus
Burrs are only on one side.	Coaxial laser is not correct.The opening of the nozzle has defects.	Align coaxial laser Replace the nozzle
Materials are discharged from above.	Power is too low The cutting speed is too high	Increase the power Reduce the cutting speed
The surface of cutting is not precise.	Air pressure is too highThe nozzle is damaged. The nozzle diameter is too large.	Reduce air pressure Replace the nozzle Install an appropriate nozzle
Stainless steel: Cutting with N2 high pressure.
Defects	Possible Cause	Solutions
Regular small droplet-like burrs are produced	The focus is too low   The cutting speed is too high	Raise the focus   Reduce the cutting speed
Irregular long filamentous burrs are produced on both sides, and the surface of large plate discolors.	The cutting speed is too lowThe focus is too high Air pressure is too low   The material is too hot	Increase the cutting speedLower the focus Increase air pressure   Cool the material
Irregular long burrs are produced on the cutting edge.	Coaxial laser is not correct.The focus is too high Air pressure is too low   The cutting speed is too low	Align coaxial LaserLower the focus Increase air pressure Increase the cutting speed
The cutting edge becomes yellow	Nitrogen contains oxygen impurities.	Use high-quality nitrogen

Light beam is diffused at the beginning.	The acceleration is too high The focus is too lowThe molten material cannot be   discharged	Reduce the acceleration Raise the focus Pass through a circular hole
The kerf is rough	The nozzle is damaged. The lens is dirty	Replace the nozzleClean the lens, and replace it if necessary.
The material is discharged from above.	The power is too low   The cutting speed is too fast Air pressure is too high	Increase the power Reduce the cutting speed Reduce air pressure