The reason why fiber laser cutting machine uses nitrogen to cut metal?

Fiber laser cutting machines use auxiliary gas when cutting materials such as steel plates or stainless steel. For example, when oxygen is used as an auxiliary gas, an exothermic reaction will occur, which is particularly obvious when cutting carbon steel. This type of solution is widely recognized.

In this process, oxygen is used at the laser beam projection point on the metal surface to heat the steel plate, bringing about an exothermic reaction, so that the regional temperature reaches the melting point, and the molten metal is blown out by the air and separated from the material, finally forming a smooth cutting surface with an oxide layer.

But on the other hand, when cutting stainless steel, because stainless steel has a higher melting point and its characteristics are different, when both cutting quality and smoothness are taken into account, the residual oxide will be formed on the metal surface when using oxidation as the auxiliary gas, so the cutting quality cannot achieve a good effect.

In order to solve this problem, after repeated research by laser experts, nitrogen was finally used as the auxiliary gas. Because nitrogen is an endothermic process, it is essentially an evaporation and ablation process, and higher pressure means higher operating costs.

The nozzle diameter has a greater impact on gas consumption, so a larger nozzle is required to cut thicker materials, so nitrogen is generally used as an auxiliary gas for cutting stainless steel.