As mentioned before there is an essential distinction when cutting with one of the two gases oxygen and nitrogen: In case of lower quality or unalloyed steel oxygen combines the melting of the metal with an exothermal combustion. Therefore, this cutting method is called flame cutting. You can therefore cut with relatively low power already thicker material. A disadvantage is that the cutting edge oxidizes and therefore is no longer suitable for welding processes in further production processes. The consumption of oxygen, which should be used in a purity of > 99.95 percent strongly depends on the nozzle diameter in the cutting optics, but typically ranges from. 0.5 - 4 m³/h. The set pressure in flame cutting varies between 0.8 and 3-4 bar.
Especially with aluminum and stainless steel nitrogen is used as the cutting gas; the exothermic combustion is not present. The material is melted alone by the laser power and is referred to as fusion cutting. Aluminum can catch fire if oxygen is used, and stainless steels are not to oxidize after a cutting process; therefore high-purity (> 99.995 %) nitrogen is used. To expel the melt in this area, you need to process higher pressures than in flame cutting. These are in the range of 6 to 20 bar. Therefore, the diameter of the nozzle is a very important parameter for gas consumption and the cost of the application. Here typically tests are necessary; these can be performed in the application laboratory of Laserline.