How to avoid "overburning" when laser cutting sheet metal?

What is overheating?

The laser cutting machine will generate a lot of heat when processing the sheet metal. Under normal circumstances, the heat will diffuse along the cut surface inside the sheet metal. In the processing of small holes by laser cutting machine, the outside of the hole can be sufficiently cooled, and the small hole inside the single hole has a small diffusion space, and the heat diffusion cannot be too concentrated and cause overburning, slagging, etc. In addition, during thick plate cutting, the molten metal accumulated on the surface during the piercing process and the high heat accumulation required for thick plate cutting will cause the auxiliary gas to be turbulent, resulting in an increase in heat, which can lead to overburning.

How to avoid overburn when laser cutting sheet metal?

1. Add cooling point or use ring cutting function

When cutting boards with sharp corners, the location where overburning is more likely to occur is often at the sharp corners. Overburning will cut the sharp corners into a round shape. At this time, you can add a cooling point at the sharp corners. Pause and blow air can effectively avoid over-burning. Or use the ring cutting function to avoid overburning caused by excessive heat caused by slow speed at sharp corners.

2. Use high-power lasers

When cutting carbon steel, a higher power laser can be used, and a bright surface cutting process can be used to effectively avoid overburning, and this cutting process can cut a finished product with no burrs and a bright cut surface. High power can effectively avoid overburning.

3. Cutting with nitrogen

In sheet metal cutting with oxygen as the auxiliary gas, nitrogen can be used for cutting. When nitrogen cutting, the material is completely melted by laser energy, and the nitrogen and the sheet metal itself will not easily react chemically. The temperature in the melting point area is relatively low, coupled with the cooling and protection of nitrogen, the response is stable and uniform, and the cutting quality is high. The section is fine and smooth, the surface roughness is low, and there is no oxide layer.

4. Increase the air pressure

When using a laser cutting machine to process aluminum alloy and stainless steel, the auxiliary gas used is nitrogen or air, which will not cause edge burning during cutting, but due to the high temperature of the material inside the small hole, the slagging phenomenon on the inside will be more frequent . In this case, burrs and dross can be reduced by increasing the pressure of the auxiliary gas.