What is the cause of metal overburning?

Fiber laser cutting machines generate a lot of heat when processing sheet metal. Under normal circumstances, the heat will spread to the inside of the sheet metal along the cutting section. However, during the processing of the small holes of the laser cutting machine, because the heat of the inner small holes cannot be diffused, too much concentration will cause problems such as overburning and slag hanging.

In addition, when cutting thick metal plates, the molten metal accumulated on the surface during the perforation process and the high heat accumulation required for thick plate cutting will disturb the auxiliary gas, resulting in an increase in heat, which may cause overburning.

 

When using a fiber laser cutting machine to process metal projects, in order to avoid the problem of over-burning, the following methods can be solved:

 

Increased cooling point when cutting metal

When cutting metal workpieces with sharp corners, the location where overburning is more likely to occur is often at the sharp corners, and overburning will cut the sharp corners into a circle. At this time, you can add a cooling point at the sharp corner, pause at the sharp corner, and blow air, which can effectively avoid over-burning.

 

Using high power fiber lasers

When cutting carbon steel, a higher power laser can be used, and the bright surface cutting process can effectively avoid over-burning.

 

Using nitrogen assisted laser cutting

In the sheet metal cutting with oxygen as the auxiliary gas, it can be replaced with nitrogen-assisted cutting. During nitrogen cutting, the metal is completely melted by laser energy, and the nitrogen gas does not easily react with the sheet metal itself. The temperature in the melting point area is relatively low, coupled with the cooling and protective effect of nitrogen, the reaction is stable and uniform, and the cutting quality is high. The cross section is smooth, the surface roughness is low, and there is no oxide layer.

 

Increase the pressure of the auxiliary gas

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