Auxiliary gas needs to be used for fiber laser cutting when cutting metal

Why should we need Auxiliary gas when we using fiber laser cutting machine cutting metal materials ?

There are four reasons to use auxiliary gas :

Firstly, the auxiliary gas will start chemical reaction with the metal material.It will help increase the working capacity.
Secondly, blowing off the slag by air and clean the cutting seam.
Thirdly, the gas will cool the area around cutting seam.It can avoid shape change of the material.
Last but most important, It protects the Focus Lens from combustion products caused by high temperature of laser beam.

Normally, fiber laser cutting can use O2 ( Oxygen) , N (Nitrogen) and Air as auxiliary gas.

Their functions are as following respectively.

N:Cutting nonferrrous metal using Nitrogen.Such as Stainless Steel and Aluminum sheet.It can cool and protect the material.Oxygen will blacken such materials .Using Nitrogen can avoid this phenomenon of going black.

Applicable Materials: Aluminum,Aluminum Alloy, Stainless Steel, Galvanized Steel Sheet, Brass.

O2: Oxygen is used in cutting Carbon Steel. As there is many Carbonaceous impurities in carbon steel.Using O2 can greatly increase the combusting speed.As well, It can accelerate cutting speed. However, there is a disadvantage.The cutting surface will be black.The cutting surface appears black or buff.

Applicable Materials: Stainless steel, Carbon Steel.

Air: Air can be provided by Air Compressor.The price is very low. Although there is about 20% Oxygen in air, the cutting efficiency is far less than Oxygen, nearly same as Nitrogen’s efficiency.

The cutting surface appears yellow.

Applicable Materials: Aluminum, Aluminum Alloy, Stainless Steel, Galvanized Steel Sheet, nonmetal etc.

Argon: Very expensive.protecting from oxidation and nitridation. Cutting surface appears yellow.

Mainly used in Titanium and Titanium Alloy.