Views: 0 Author: XDLASER Publish Time: 2022-02-05 Origin: XDLASER
Metal sheet fiber laser cutter is widely used in the manufacturing industry, especially the optical fiber laser cutting machine, which has developed rapidly in recent years. Originally, it can only carry out plane cutting, but now it can carry out three-dimensional cutting. Up to now, no matter how the technology of fiber laser cutting machine develops, the cutting process is inseparable from the use of auxiliary gas. Why does auxiliary gas always be used in cutting?
There are usually these kinds of auxiliary gases, compressed air, oxygen, nitrogen and argon. The main operations of these gases are as follows:
1、 Let the auxiliary gas react with metal materials to increase the cutting speed
2、 Help the equipment blow the slag from the cutting area and clean the cutting seam
3、 Cool the area adjacent to the slit and reduce the range of heat affected zone
4、 Protect the focusing lens and prevent combustion products from polluting the optical lens
1. Compressed air can be made by air compressor, because air is everywhere and the cost is relatively low. Processing manufacturers mostly use compressed air for auxiliary cutting. The air contains about 78% nitrogen and 21% oxygen, and a small amount of oxide film will appear on the cutting surface, which can prevent the film layer from falling off. The cutting effect of compressed air is similar to that of nitrogen, and the cutting section is generally yellow. It is generally used when the plate is relatively thin and the requirements for the cutting surface are not high.
Compressed air is not recommended to be used in the cutting of stainless steel and aluminum alloy materials. The cutting process is easy to oxidize the base metal and affect the original stability of the material.
2. Oxygen mainly plays the role of combustion supporting. It can increase the cutting speed and thicken the cutting thickness. At the same time, the generated oxide film will improve the beam spectral absorption factor of the reflective material, and the end face of the notch will be black or dark yellow.
Oxygen is suitable for thick plate cutting, high-speed cutting and very thin plate cutting. Oxygen is often used in the cutting of some large carbon steel plates and thick carbon steel plate structures.
3. Nitrogen is generally used for auxiliary cutting. When cutting some metals, oxygen will form oxide film on the cutting surface. Nitrogen can be used for non oxidative cutting to prevent the appearance of oxide film. The non oxidation cutting mask has the characteristics of direct welding and coating, strong corrosion resistance, and the end face of the incision is white. Nitrogen can be selected for auxiliary cutting of products with high requirements for cutting end face and exposed without treatment.
It is mainly suitable for cutting stainless steel, electroplated steel plate, brass, aluminum, aluminum alloy and other metal plates.
4. Argon is an inert gas and rarely reacts with materials. It is used to prevent oxidation and nitriding in laser cutting machine cutting and often used in welding. The end face of the notch is generally white. Compared with other processing gases, the cost is higher.
It is mainly suitable for cutting titanium, titanium alloy and other special metal materials.
The use of various gases is determined according to the properties of the materials to be cut. Most common metal plates are carbon steel, stainless steel and aluminum alloy. Carbon steel plates are generally cut with oxygen, and the oxygen purity is recommended to be within 97.5% - 99.5%. Carbon steel will undergo oxidation reaction in pure oxygen to release a lot of heat, so as to separate the whole plate. The reduction of gas purity will reduce the cutting speed and increase the gas consumption. Therefore, selecting the appropriate gas and purity can effectively speed up the production efficiency. Therefore, in the cutting and blanking process, we must select the appropriate gas according to the characteristics of the cutting products.
