Cutting Gas For Fiber Laser Cutting Machine
The laser beam is focused by the lens in the cutting head and directed onto the workpieces by a nozzle. The cutting gas also flows through this nozzle. Depending on the application, oxygen, nitrogen or compressed air are used as the cutting gas.
Nitrogen cutting features:
The main advantages of nitrogen cutting is high cutting quality, widely used in cutting processing, but its disadvantage is high cost.
1) Cutting quality
According to the use of auxiliary gas, laser cutting machine can be divided into oxygen, nitrogen two cutting methods. Oxygen is involved in combustion during oxygen cutting, and the melting point is close to the boiling point. High temperature lead to severe reaction, can not guarantee smooth section; the other with the oxidation reaction, increased heat affected zone, the cutting quality is relatively poor, prone to slit width, cross-section twill, surface roughness and welding slag quality defects. Nitrogen cutting material completely rely on laser energy melting, nitrogen blowing out the slit and avoid inappropriate chemical reaction. The temperature of the melting point area is relatively low, with nitrogen cooling, protection, the reaction is stable, uniform, high-quality cutting. Smooth cross-section, low surface roughness, and no oxide layer.
2) Cutting costs
The price of high purity nitrogen is three times that of high purity oxygen. For example, cutting 2mm thick stainless steel plate, the oxygen needs pressure 4 * 105Pa, air consumption 2.3m3 / h, nitrogen is corresponding to the 14 (1 ~ 4) * 105Pa, nitrogen gas needs * 105Pa, 15.2m3 / h. Laser cutting machine and nitrogen cutting requires high power, a corresponding increase in power consumption. The total cost of nitrogen cutting oxygen cutting more than 15 times.
3) Processing range
Oxygen assisted combustion increases the heat and increases the thickness of the cut. The advantage is low cost, mainly used in carbon steel. Nitrogen does not assist combustion, the melting zone temperature is low, suitable for processing aluminum, brass and other low melting point materials. Laser cutting machine Nitrogen protection Slit is not oxidized, can also be used for the oxidation of stainless steel cutting, processing see the following data.