How to avoid overburning when laser cutting sheet metal？

Metal laser cutting machines generate a lot of heat when processing sheet metal. Under normal circumstances, the heat generated by cutting will diffuse along the slit into the processed sheet metal and be fully cooled. When processing small holes, the outside of the hole can be fully cooled, but the small hole part inside the single hole is prone to overburning and slag due to the small space for heat diffusion and excessive heat concentration. In addition, when cutting thick plates, the molten metal and heat accumulated on the surface of the material during perforation will cause the auxiliary airflow to be turbulent and the heat input to be too much, thus causing overburning.

How to avoid overburning when laser cutting sheet metal?

【1】 Add cooling points at corners

When cutting sharp-angle metal sheets, the position where overburning is more likely to occur is often at the sharp corner. Overburning will cut the sharp corner into a round shape. At this time, a cooling point can be added at the sharp corner, and the sharp corner can be paused and blown.

【2】Use high-power laser

When cutting carbon steel, a higher-power laser can be used. The bright surface cutting process can effectively avoid overburning, and this cutting process can produce burr-free and bright-cut finished products.

【3】Use nitrogen cutting

In sheet metal cutting with oxygen as the auxiliary gas, nitrogen can be switched to cutting. When cutting with nitrogen, the material is completely melted by laser energy, and nitrogen blows out the cut seam and avoids inappropriate chemical reactions. The temperature in the melting point area is relatively low, and with the cooling and protective effect of nitrogen, the reaction is stable and uniform, and the cutting quality is high. The cross-section is delicate and smooth, the surface roughness is low, and there is no oxide layer.

【4】Increase gas pressure

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