What is overburn?
The metal laser cutting machine will generate a lot of heat when processing the plates. Under normal circumstances, the heat generated by cutting will diffuse to the processed plates along the cutting seam for full cooling. In the process of metal laser cutting machine, the outer side of the hole can be fully cooled, while the inner side of the single hole is easy to cause excessive burning and slag hanging due to small heat diffusion space and excessive concentration of heat energy. In addition, during the thick plate cutting, the molten metal accumulated on the material surface during the perforation and the heat accumulation will lead to the disorder of the auxiliary air flow and excessive heat input, which will lead to the cutting overburn.
1) According to the concept of “thermal energy is too concentrated to cause cutting burning and slagging”, we naturally thought that we could speed up the heat diffusion with manual assistance, and then the corresponding solution appeared: [add cooling points at corners]. During the cutting process at the corner (sharp corner) of the sheet, set the cooling point manually, and let the laser head blow auxiliary gas here for a while to help the sheet dissipate heat. This solution to the problem of too few boards will be the most affordable and cheapest solution. I don’t believe you can look at the remaining three solutions with Xiao Bian.
2) In the sheet metal cutting with oxygen as the auxiliary gas, the [Nitrogen cutting] can be switched. After all, we all know that laser cutting is mainly divided into two cutting methods: oxidation cutting and melting cutting. The former relies on the chemical reaction between the plate and oxygen, while the latter simply relies on the energy of laser to melt the plate. If oxygen is replaced with nitrogen, the temperature in the melting point area is lower than that in the oxidation cutting area. With the cooling and protection of nitrogen, the reaction 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. This method is expensive to solve the problem of over burning of plates, but the effect is significant.
3) In addition, we can also solve the problem of cutting overburn by [increasing air pressure]. However, it should be noted that this method is generally applicable to nitrogen or air processing of aluminum alloy and stainless steel. In this case, the cutting of stainless steel and aluminum alloy generally does not occur overburning. However, due to the high temperature of the materials inside the small hole, another phenomenon other than overburning may occur, that is, the slag hanging on the inside is relatively frequent. In this case, burr and slag can be reduced by increasing the pressure of auxiliary gas.
4) The last method is to [replace the high-power laser]. The bright surface cutting process can effectively avoid the over burning of plate cutting.
To sum up, it is the first method to solve the problem of over burning of plates. Have you learned it?
What is overburn?