Laser Cutting of Stainless Steel
Stainless steel can be readily cut using laser methods. Although classed as thermal cutting methods, the heat input and heat generated is low. Good quality cut edges can be produced with little risk of distortion to the steel.
The properties of the stainless steel, including magnetic permeability, should not be affected by laser cutting. Any distortion experienced during or after cutting should only be due to the relief of 'self restraint' on cutting and not due to any changes in the material from the cutting method.
Speed and quality of cut
For a given type and power of the laser equipment, the speed and quality of cut can be altered by the choice of cutting or shielding gas.
Although lasers work without the use of a vacuum and do not need a gas to make the cut, shielding gass are used around the cutting nozzle. This gas helps blow molten metal away from the cut but if oxygen is used enhances the cutting speed through an exothermic reaction under the cutting beam. Nitrogen can be used instead of oxygen but this gives reduced cutting rates.
A summary of cutting speeds on 1.4301 304 stainless steel sheet using a 1.5 kW CO2 laser with either oxygen or nitrogen shielding gas is shown in the table below.
| Sheet thickness (mm) |
Cutting speed (M/min) |
| . |
Oxygen |
Nitrogen |
| 1.0 |
9.0 |
8.0 |
| 2.0 |
5.0 |
3.5 |
| 3.0 |
3.0 |
2.0 |
| 6.0 |
1.5 |
0.5 |
|
