The residue on the surface of the metal after cutting is called hanging slag. Laser cutting machine will generate a lot of heat during processing. Generally speaking, the heat generated during cutting will spread to the whole workpiece along the cutting seam, and then the workpiece will be fully cooled. However, when cutting small hole workpieces, the outside of the hole can be fully cooled, and the inside of the hole can cause slag hanging due to the small space for heat diffusion and excessive heat concentration. In addition, when cutting thick plates, the molten metal accumulated on the surface of the material during perforation and the heat accumulation will disturb the auxiliary air flow, and the heat input will be too much, resulting in slag hanging.
How are burrs produced?
In fact, burrs are excessive residue particles on the surface of metal materials. When the laser cutting machine is processing the workpiece, the energy generated by the laser beam irradiating the workpiece surface makes the workpiece surface vaporize and evaporate to achieve the purpose of cutting. But there is a device that we should pay attention to, which is gas. Gas is to blow off the slag on the surface of the workpiece after the irradiation surface of the workpiece is vaporized. If gas is not used, the slag will form burrs on the cutting surface after cooling. Therefore, the purity of the gas should be high, and do not use cylinder gas, because after two filling, the purity is not good, and the gas is also wasted.
Another reason is the quality problem of the equipment itself, as well as the parameter setting factor. Therefore, when customers buy laser cutting machines, they should have experienced operators debug the equipment. Therefore, we should try to adjust the cutting parameters to the best. The air pressure, flow, focal length, cutting, speed, etc. should be adjusted many times. High quality workpieces cannot be cut by relying on the parameters provided by the machine.
If a material has burrs, the material can be classified as inferior. The more burrs, the lower the quality.
How to solve it?
After slag hanging occurs in cutting, first find out the reasons from the following points, and then adjust it to solve the formation of slag hanging.
1. Insufficient laser output power
When cutting thick plates, the power is not enough to melt the whole plate. If the power can be adjusted, you can increase the power to continue to test whether it can be cut off. If the power has been adjusted to the maximum, you need to replace the laser with a higher power.
2. Deviation of laser beam focus
Too close or too far focus will affect the cutting quality, which can only be adjusted by inspection and according to its offset position.
3. Insufficient air pressure of auxiliary gas
The auxiliary gas can blow away the slag during cutting and cool the heat affected zone of cutting. If the air pressure is too small, the residue will not be blown out of the workpiece or the workpiece will not be cooled in time, resulting in the formation of slag hanging. Adjust the air pressure to the appropriate size.
4. Cutting speed too fast or too slow
The cutting speed of laser cutting is too fast, which will cause the workpiece to be unable to be cut in time, the cutting surface will form diagonal lines, and there will be slag hanging in the lower half area. If the cutting speed is too slow, there will be over melting, the cutting surface will be rough as a whole, the cutting seam will become wider, and the slag will hang on the upper half.
The above is the reason why the laser cutting machine leaves residue on the metal surface after cutting. We can adjust the equipment according to the above solutions to achieve better cutting effect.