Influence of different auxiliary gases on the cutting quality of 1500*3000 metal CNC fiber laser cutting machine

First of all, let's understand the process of laser cutting: after the laser generated by the oscillator passes through the lens, it is concentrated at a point to form a very small spot. By precisely controlling the distance between the lens and the plate, the laser spot is guaranteed to be stable in the material thickness direction At a certain position, due to the convergence of the lens, the laser energy with a very large power density is gathered at the spot, and the power density can usually reach 106-109W/cm2. After the material absorbs the spot energy, it melts instantly. The liquid blows off the material to complete the cutting process.

In the whole cutting process, the main function of the auxiliary gas is to form a driving force to remove the molten metal liquid from the material itself. In this process, different types of gas have different effects on the material and section:

01. When oxygen is used as auxiliary gas

While blowing away the molten metal liquid, an oxidation reaction will also occur to promote the endothermic melting of the metal, thereby achieving the melting of thicker materials, a process that will significantly improve the processing capability of the laser. But at the same time, due to the presence of oxygen, the cut surface of the material will be oxidized significantly, and the quenching effect will be produced on the material around the cut surface, which increases the hardness of this part of the material and has a certain impact on subsequent processing.

02. When nitrogen is used as auxiliary gas

A protective atmosphere is formed around the molten metal liquid to prevent the material from being oxidized, thereby ensuring the quality of the cut surface. But at the same time, because nitrogen has no oxidizing ability and cannot enhance heat transfer, it will not help 1500*3000 metal CNC fiber laser cutting machine improve cutting ability like oxygen. In addition, when nitrogen is used as an auxiliary gas, the consumption of nitrogen is very large, resulting in a higher cutting cost than when other gases are used.

03. In the constituent gas of air

Nitrogen accounts for about 78% and oxygen accounts for about 21%. When air is used as an auxiliary gas for cutting, the cutting section will inevitably undergo oxidation reaction due to the presence of oxygen, but at the same time, due to the existence of a large amount of nitrogen, the oxidation reaction caused by oxygen is insufficient. In order to enhance the heat transfer, the cutting ability will not increase, so the air cutting effect can be understood as between nitrogen cutting and oxygen cutting, and the advantage is that the cost of air cutting is very low, all the cost is the air compressor to provide air. The resulting power consumption, as well as the consumption of the filter element in the air line.

According to the above cost analysis, when air is used as auxiliary gas for 1500*3000 metal CNC fiber laser cutting machine, the cutting cost per hour can be reduced by 23.7% compared with that when nitrogen is used. Such a reduction in cutting cost can reduce the overall factory processing cost of the enterprise. play a very important role. In addition, when analyzing the power consumption of air compressors, this paper considers that many companies are currently using non-variable screw air compressors. If a permanent magnet variable frequency screw air compressor is used, the power saving of a single air compressor can reach 50%. , the cutting cost of using air can be reduced by 36.2% compared to using nitrogen.