What is over-burning?
A lot of heat is generated when laser cutting and processing sheet metal parts, and the heat is not diffused in time, resulting in edge burning. When using the fiber laser cutters to cut small holes, the outside of the aperture can be cooled, while on the inside of the hole has little space for heat to diffuse, and the heat is too concentrated to cause over burning and slag. In addition, in the cutting of thick plates, the molten metal and heat generated during the perforation accumulate continuously on the surface of the material. This will cause the auxiliary airflow to be disordered and the heat input too much, leading to overburning and edge burning directly.
How to avoid over burning?
Mild steel cutting
In the process of carbon steel cutting with oxygen as auxiliary gas on a fiber laser metal cutting machine, the key to solving the problem is how to prevent the generation of oxidation reaction heat. We can use oxygen during perforation and then switch to auxiliary air or nitrogen for cutting. This method can process small holes of 1/6 thick plate. Setting pulse cutting conditions at low frequency and high peak output power can reduce heat output and help to optimize cutting conditions. Setting the states as a single pulse laser beam, high peak output with high energy intensity, and low-frequency conditions can reduce the accumulation of molten metal on the material’s surface during the perforation process and reduce the heat output.
Stainless steel and aluminum cutting
In processing such materials, the auxiliary gas used is nitrogen, so no edge burning occurs during cutting. However, due to the material’s high temperature inside the small hole, the phenomenon of slag hanging on the inside is also relatively frequent. The solution is to increase the pressure of the auxiliary gas and set the conditions to high peak output, low-frequency pulse. When the auxiliary gas uses air, it is the same as when nitrogen is used. Overburning will not occur, but it is easy to form slag at the bottom. We need to set the conditions to high auxiliary gas pressure, high peak output, low-frequency pulse conditions.
