Fiber laser cutting machines are used to cut different kinds of materials, and the use of gas is an essential part of the cutting process. So how do you choose the right gas and pressure for a fiber laser cutter? This will be the most comprehensive guide on the topic.
Depending on the type of cutting material, the choice of gas and pressure has a significant impact on the cutting quality of a fiber laser cutting machine.
The fiber laser cutter processes materials such as stainless steel and aluminum, and generally uses nitrogen as an auxiliary gas for cooling and protection. When cutting carbon steel, oxygen is used to cool the cutting head and to accelerate combustion for a more efficient cutting process. The cutting gas helps dissipate heat, supports combustion, and blows away molten slag to achieve a better-quality cutting section.
The influence of gas and pressure on cutting quality
- When the gas pressure is not sufficient:
Quality effects: During cutting, molten slag will appear, and the required cutting speed cannot be achieved, which affects production efficiency.
- When the gas pressure is too high:
Quality effects: The cutting surface is rough and the slit is wider, at the same time, the cutting section may become partially melted, resulting in poor cutting quality.
The influence of gas pressure on piercing
a) Oxygen:
Oxygen can be used as a cutting gas, for cooling the cutting head, and for dust removal inside the optical path to protect the lens and extend its service life. The oxygen reaction can greatly improve the cutting efficiency, and the oxide film produced will also increase the spectral absorption factor of the reective material beam.
Mainly suitable for cutting the following materials: Rolled steel, rolled steel for welding structure, carbon steel for mechanical structure, high tension plate, tool plate, stainless steel, electroplated steel plate, copper, copper alloy, etc.
b) Nitrogen:
Nitrogen can prevent oxide-free cutting of the oxide film. Pure nitrogen is used as the gas (cooling property) for cutting stainless steel with a purity of 99.9%, high-purity nitrogen is used as the gas used for the laser, with a purity of 99.999%.
Mainly suitable for cutting: Stainless steel, electroplated steel plate, brass, aluminum, aluminum alloy, etc.
c) Air:
An air compressor can supply air directly, which makes it more economical than other gases. Mainly suitable for cutting: Aluminum, aluminum alloy, stainless steel or copper, brass, electroplated steel plate, non-metal, etc.
d) Argon:
It is used to prevent oxidation and nitridation and can also be used in welding.
Carbon dioxide: high-purity carbon dioxide: used as laser gas, purity: 99.999%.
Mainly suitable for cutting: Titanium, titanium alloy, etc.
Selection of cutting gas pressure for fiber laser cutting machine
When laser drilling, higher gas pressure is generally used for thin plates. For thicker plates, specific piercing methods are applied to avoid the negative effects of low air pressure on lens protection. When the laser cutting machine cuts ordinary carbon steel, the thicker the material, the lower the pressure of the cutting gas. When cutting stainless steel, the cutting gas pressure increases with the material thickness.
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