When are the three auxiliary gases of air, oxygen and nitrogen used for laser cutting?

The laser cutting machine uses different auxiliary gases to cut different materials. The thickness of the cutting material is different, the pressure of the auxiliary gas and the required flow rate are different.

Common auxiliary gases are: air, oxygen, nitrogen, and oxygen for cutting carbon steel. The purity requirements are generally 99.5% or higher. The main function is to support combustion and blow off the cut melt. The pressure and flow rate are different for each laser cutting machine manufacturer, which is inseparable from the size of the cutting nozzle and the thickness of the cutting material. Generally, the pressure is required to be 0.3-0.8Mpa, and the cutting nozzle is generally 0.02-0.05Mpa. The flow rate varies according to the thickness of the cutting material. For example, when cutting 22mm carbon steel, the flow rate of some manufacturers must reach 10M3/h (including the protective oxygen for the double-layer cutting nozzle).

The laser cutting machine must use auxiliary gas in the processing of products. The auxiliary gas is mainly used in: 1, laser gas (the gas used to generate the laser in the laser generator)

2. Compressed air (usually used to protect the light path, some manufacturers also use it as a protective gas) 3, auxiliary gas (the gas sprayed from the cutting nozzle of the cutting machine as the host said)

Nitrogen gas is used to cut stainless steel. The role is to prevent the oxidation reaction and blow off the melt. There are high requirements for the purity of nitrogen (especially stainless steel above 8mm, which generally requires a purity of 99.999%). The pressure requirement is relatively large, generally above 1Mpa. If you want to cut stainless steel above 12mm or thicker to 25mm, the pressure is required. Higher, above 2Mpa or higher. The flow varies according to the model of the cutting nozzle, but they are all very large. For example, cutting 12mm stainless steel requires 150m3/h for some manufacturers, and cutting 3mm, as long as the flow is below 50m3/h.

In terms of cost, oxygen used for cutting carbon steel is relatively cheap, and the amount of nitrogen used for cutting carbon steel is large, and the amount of nitrogen and purity of thicker stainless steel are required to be high and the cost is high.

Among the three gases, air has the lowest cost and is also the choice of the most customers. However, if the air compressor is not well selected, it will be extremely unfavorable to the operation of the fiber laser cutting machine, which can easily cause oily or dirty substances in the protective lens of the machine, which will cause the optical path of the fiber laser cutting machine to deviate or sometimes fail to cut during the cutting process. Factors such as wear.

The compressed air discharged from the air compressor undergoes a series of treatments to become clean and dry gas, and finally divided into three paths. One part is composed of high-purity oxygen and high-purity nitrogen to form a cutting gas for the cutting head. One part is used as a power source to supply the cylinder of the clamping workbench, and the last part is used to purge and remove dust from the optical path system to maintain the normal operation of the laser cutting machine.