The laser cutting of stainless steel, especially of a heavy thickness, is hampered by the process of slagging cut due to the presence in the metal of alloying elements that affect the melting point of the metal and its oxides. So, it leads to formation refractory oxides that interfere with the distribution of laser emission over processed material. The cutting process becomes more complicate also due to a low flow of molten oxides, which is typical for stainless chromium-nickel and high-chromium steels.
High purity nitrogen which is applied at high pressure (usually up to 14 … 20 bar) is used for high-quality cutting. The cutting process of a large thickness stainless steel requires deepening of a focal point of the laser into the metal. As a result, the diameter of the inlet becomes larger and the flow of gas into the melting zone of the metal increases.