With the increasingly fierce competition in the laser processing industry, how to improve work efficiency and reduce costs has become a concern for most users. Fiber laser cutting machine has quickly become the mainstream of the market due to its advantages such as fast cutting speed, small deformation of materials, and high processing accuracy. The application of high-power lasers has greatly improved the efficiency of laser processing. The limit cutting speed of thin plates has been able to challenge the control limit of mechanical properties, and the cutting process of medium and thick plates is also constantly breaking.

The figure above is a comparison of the speed of nitrogen cutting of stainless steel corresponding to different power laser cutting machines. It can be seen that for stainless steel cutting, the higher the laser power, the faster the cutting speed.

There are three kinds of cutting auxiliary gases commonly used in fiber laser cutting machines: oxygen, nitrogen and air. However, because the cost of nitrogen and oxygen is higher than that of compressed air, and the prices of nitrogen and oxygen have increased year by year, the use of air as a cutting auxiliary gas can greatly reduce the cost of production.

Oxygen is mainly used for cutting carbon steel. The principle is that oxygen reacts with metals and emits a large amount of oxidation heat. At the same time, a certain pressure will blow out oxides and slag from the reaction zone, forming cuts in the metal. Because the oxidation reaction during the cutting process generates a large amount of heat, it does not require too much power, but the corner of the cutting tip is easily overburned.

Nitrogen is mainly used for cutting stainless steel and aluminum plates. At the same time, it can also cut carbon steel plates of a certain thickness. The higher the power, the greater the thickness of the carbon steel plates that can be cut. Nitrogen cutting relies on the energy of the laser to melt the metal, and the high pressure blows away the melt to ensure that unreasonable chemical reactions occur during the period. On stainless steel and aluminum plate cutting, a brighter section effect can be obtained, and the sharp corner effect is also better.

The air itself exists in the atmosphere, and it is compressed into an air storage tank by an air compressor, and then filtered, cooled, and dried to remove water and oil from the air, and then it can be used. The cutting principle of air is similar to nitrogen, but because the air contains about 20% oxygen, it can make up for the deficiency of oxygen and nitrogen to a certain extent. Compared with nitrogen cutting, the air cutting section is darker, but does not hang slag. After polishing, the section can also achieve a brighter effect. In terms of speed, air cutting stainless steel is slightly faster than nitrogen, but the advantage is not obvious. At the same time, due to the different quality of carbon steel plates from different sources, the cutting effect will be greatly different, so the stability of the process of air cutting carbon steel needs to be further verified by the market. In terms of cutting speed, air has no advantage compared to nitrogen, but the two are far ahead of oxygen in thickness of 8mm and below. Of course, the cross-section brightness and bottom surface finish of oxygen-cut carbon steel are better than air and nitrogen.

Comprehensive consideration, in the case of relatively loose requirements, air cutting has a large cost advantage. However, it should be noted that when using air cutting, the air must be filtered by the cold dryer, and the air compressor and the cold dryer need regular maintenance. If the air entering the cutting head contains water and oil, it will cause fogging of the protective lens in a short time and affect the cutting quality. At this time, if the protective lens is not replaced in time, the internal temperature of the cutting head may also rise under the irradiation of high power beams. High, may cause damage to the internal lens group.

For factories with a large processing volume, with high-power cutting machines, air cutting can bring them higher efficiency and lower costs. The benefits in this regard are much higher than the cost of secondary processing of the workpiece. But for small processing plants, air cutting may not be able to reduce costs. Therefore, whether to use air cutting needs to be determined according to its own output.