When laser cutting sheet metal parts, a large amount of heat will be generated, and the heat is not diffused in time, resulting in edge burning. In the processing of small holes by fiber laser cutting machine, the outside of the hole can be cooled, but the small hole inside the hole has a small space for heat diffusion, and the heat is too concentrated to cause overburning and slag hanging. In addition, in thick plate cutting, the molten metal and heat accumulation accumulated on the surface of the material during piercing will cause turbulence of the auxiliary air flow and excessive heat input, which will lead to over burning and edge burning.
Solutions for edge burning by fiber laser cutting machine:
1、 Solution to overburning during carbon steel processing: in carbon steel cutting with oxygen as auxiliary gas, the key to solve the problem is how to prevent the generation of oxidation reaction heat. The method of assisting oxygen during piercing and then switching to assisting air or nitrogen for cutting can be adopted. This method can process small holes of 1 / 6 thick plate. The pulse cutting conditions with low frequency and high peak output power can reduce the heat output, which is conducive to the optimization of cutting conditions. Setting the conditions to single pulse laser beam, high peak output with high energy intensity and low frequency can reduce the accumulation of molten metal on the material surface during the piercing process and reduce the heat output.
2、 Solution for processing aluminum alloy and stainless steel by fiber laser cutting machine: in the processing of such materials, the auxiliary gas used is nitrogen, and edge burning will not occur in the cutting. However, due to the high temperature of the material inside the small hole, the phenomenon of slag hanging inside is also relatively frequent. The solution is to increase the pressure of the auxiliary gas and set the conditions to high peak output and low frequency pulse conditions. When air is used as the auxiliary gas, it will not burn like when nitrogen is used, but it is easy to have slag hanging at the bottom. It is necessary to set the conditions as high auxiliary gas pressure, high peak output and low-frequency pulse conditions.