Why is nitrogen recommended for laser cutting of stainless steel?

When cutting steel plate or stainless steel and other materials, laser cutting machine will use the aid gas, such as the use of oxygen as the aid gas, will produce exothermic reaction, especially obvious when cutting carbon steel, this type of program 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 an exothermic reaction, so that the temperature of the area reaches the melting point, and the melted metal is blown out and separated from the material, eventually forming a smooth, cut surface with an oxide layer.

But on the other hand, when cutting stainless steel, because stainless steel has a higher melting point, its characteristics are different, when the cutting quality and smoothness are included in the assessment, because the oxidation as a paving gas will form residual oxides on the metal surface, so the cutting quality can not achieve better results.

In order to solve this problem, after repeated research by laser experts, nitrogen was finally adopted as the auxiliary gas, because nitrogen is an endothermic process, in essence, the process of evaporation and ablation, higher pressure means higher operating costs.

Nozzle diameter has a greater impact on gas consumption, so cutting thicker materials requires a larger nozzle, so cutting stainless steel generally takes nitrogen as an auxiliary gas.