Fiber laser cutting machine will generate a lot of heat during cutting. Under normal circumstances, the heat generated by cutting will spread along the cutting seam to the processed sheet metal for cooling. In the processing of small holes by fiber laser cutting machine, the outside of the hole can be cooled, but the small hole part inside the single hole has small space for heat diffusion, and the energy is too concentrated, resulting in over burning, slag hanging, etc. In addition, in thick plate cutting, the molten metal accumulated on the surface of the material during perforation and the heat accumulation will make the auxiliary air flow disordered and the heat input too much, resulting in overburning.
How to solve the problem of edge burning in fiber laser cutting machine?
1. Solution of Overburning of fiber laser cutting machine in carbon steel hole cutting: 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 auxiliary oxygen during perforation and lagging switching to auxiliary air or nitrogen can be adopted for cutting. This method can process small holes in 1/6 thick plates. Pulse cutting conditions with low frequency and high peak output power can reduce heat output, which is conducive to the optimization of cutting conditions. Setting the conditions as single pulse laser beam, high peak output of energy intensity and low frequency conditions can reduce the accumulation of molten metal on the material surface and reduce the heat output during the perforation process.
2. Solution of optical fiber laser cutting machine in aluminum alloy and stainless steel cutting: 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 slag hanging phenomenon inside will be more frequent. The solution is to increase the pressure of the auxiliary gas and set the condition as the pulse condition of high peak output and low frequency. When auxiliary gas is used with air, it will not overburne as when nitrogen is used, but it is easy to have slag hanging at the bottom. The conditions need to be set to pulse conditions with high auxiliary gas pressure, high peak output and low frequency.