How to choose auxiliary gas

How to choose auxiliary gas ,As we all know,we need auxiliary gas when cutting metal,so I will introduce it briefly:

Typically, O2 (oxygen), N2 (nitrogen) and compressed air are auxiliary gas for fiber laser
cutting.

Why should we choose auxiliary gas,there are four reasons:
1. Firstly, the auxiliary gas could offer better effect when cutting different metal.
2. Secondly, blow away the slag with air and cleaning slits.
3. Thirdly, the gas could cooling the area around the slit, which avoids material shape changing.
4. The last,protacting the lens,to avoid the residue adhering on the lens,prolong the useful life of quick-
wearing parts.

The functions of three gas as follows.

1.Oxygen could cut carbon steel,because carbon steel contains many carbon impurities and O2 could offer
combustion, Using O2 can greatly increasing the cutting speed and cutting thickness ,thus improve the cutting
efficiency,however, there are disadvantages that if cutting SS ,the surface would turning yellow.

Applicable materials:carbon steel.

2.Nitrogen is used to cut non-ferrous metals such as stainless steel and aluminum… It cooling and protecting
the material, because such materials are easily blackened by oxygen,this black phenomenon can be avoid by
using Nitrogen(according to my technician,in practice,it is not absolutely to avoid blackening surface,but the
colour changing is subtle)

Applicable materials: aluminum, aluminum alloy, stainless steel, galvanized steel, brass…

3.Compressed Air: air compressor could provides air,low running cost ,although the air contains about 20%
oxygen,the cutting efficiency is much lower than oxygen,and the cutting thickness decreased as well, the
cutting surface may turning yellow.

Applicable materials: all metal

In short,when cutting Carbon steel, auxiliary gas is O2;when cutting Stainless steel,we usually use N2.

So.It’s important to choose suitable gas to cut different materials.