Influence of different auxiliary gases on cutting quality

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:

1. When oxygen is used as an auxiliary gas, while blowing away the molten metal liquid, an oxidation reaction will also occur to promote the endothermic melting of the metal, so as to achieve the melting of thicker materials. This process will significantly improve the processing ability of the laser. But at the same time, due to the presence of oxygen, the cut surface of the material will be significantly oxidized, and the material around the cut surface will be quenched, which will increase the hardness of this part of the material and have a certain impact on subsequent processing.

2. When nitrogen is used as an auxiliary gas, a protective atmosphere will be 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 improve cutting ability as oxygen does. 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.

3. Among the constituent gases 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 existence of oxygen, but at the same time due to the existence of a large amount of nitrogen, The oxidation reaction brought by oxygen is not enough to enhance the heat transfer, and the cutting ability will not improve, 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 costs It is the power consumption caused by the air compressor to provide air, as well as the consumption of the filter element in the air pipeline.