Laser cutting is the use of a focused high-power density laser beam to irradiate the workpiece, so that the irradiated material is quickly melted, vaporized, and ablated, and the molten material is blown away by the high-speed airflow coaxial with the beam. to realize the cutting of the workpiece. Compared with other cutting methods, laser cutting has the characteristics of fast cutting speed and high quality, which are summarized as follows:
(1) The cutting quality is good. Due to the small laser spot, high energy density and fast cutting speed, laser cutting can obtain better cutting quality; (2) Laser gas cutting has a narrow incision, parallel to both sides of the incision, and good perpendicularity to the surface; (3) The cutting surface is smooth and clean, it can even be used as the last process without mechanical processing, and the parts can be used directly; (4) After the material is laser cut, the width of the heat-affected zone is very small, and the performance of the material near the cutting seam is almost unaffected. The deformation of the workpiece is small, and the cutting precision is high; (5) Fast cutting speed, for example: 2500W laser cutting 1mm thick cold-rolled carbon steel plate, the cutting speed can reach 16-19m/min; (6) Non-contact cutting, no contact between the nozzle and the laser cutting workpiece, no tool wear.
The laser cutting machine can meet the cutting requirements of various materials and complex shapes, but in addition to the efficient and stable laser, the auxiliary gas is also a key factor to ensure the cutting quality of the workpiece. Laser cutting generally uses nitrogen, oxygen and air as auxiliary gases.
Nitrogen (≦1.4MPa) is mainly used for cutting stainless steel materials to ensure the quality of stainless steel in the cutting section. Generally, negative focus cutting is used when cutting thicker plates to obtain the best cutting effect. The cutting effect of stainless steel sheet is the best and the speed is fast with high cut quality; Oxygen (≦1MPa) mainly cuts carbon steel materials. Generally, when cutting thicker plates, positive focus cutting is used to obtain the best cutting effect; compressed air (≦0.8MPa) has poor cutting performance, but applicability better. Pressurized compressed air (medium and low pressure 1.4-1.6MPa) can cut stainless steel materials, the cutting section is black and yellow, and the texture is fine; it can also cut carbon steel materials, the cutting section and oxygen cutting are not much different, but the cutting speed is slightly slower, not very obvious.
Because the cost of nitrogen and oxygen is higher than that of compressed air, the laser cutting industry has generally adopted compressed air as an auxiliary gas in the past two years. Its advantage is mainly to save production costs. The unit consumes 80 kwh (1 RMB/kW/h) per day, which is equivalent to the working time of 15 bottles (25 RMB/bottle) of oxygen, and can save 70,000 RMB/unit per year. And it can effectively improve the cutting ability and increase the cutting thickness. Compared with oxygen, the slag is slightly more and the speed is slower, but the difference is not very obvious, and it basically does not affect the usage.
In the context of increasingly fierce competition in the fiber laser cutting industry, increasing the added value of products by increasing the technical difficulty of products and improving the level of product industrial design is one of the means for most companies to gain competitive advantage. As an ideal auxiliary gas for laser cutting, compressed air can not only help complete high-quality cutting tasks, but also reduce costs and improve efficiency for enterprises. However, in the actual laser cutting operation, the quality of compressed air has a very direct impact on the quality of laser cutting.
Compressed air contains water mist and oil. If it is not cleaned, the high-pressure jet on the protective mirror of the laser cutting head will seriously affect the transmission of the laser beam, disperse the focus, and cause the product to be unable to penetrate and cause waste. If it is a super high-power laser cutting machine, as long as the protective mirror or nozzle surface sticks a little very thin oil film or water mist, it may also cause the high-energy laser to burn the laser head. Since the price of the laser head of the ultra-high power laser cutting machine (above 12000W) is more than 20,000 RMB, the general air compressor supplier cannot handle the oil and moisture in the compressed air well, so many users of the ultra-high power laser cutting machine cutting machine are unwilling to take the risk of using compressed air as auxiliary gas. Therefore, the choice of the laser air compressor model is extremely important, and the laser cutting integrated air compressor came into being.
In the future global economic recovery, laser, as a key technology for intelligent manufacturing equipment, will play a more important role. This requires laser cutting air compressor manufacturers, which are important gas-assisted equipment, to continuously work on gas cleanliness, operational stability, and product energy efficiency to contribute to the high-quality development of the laser industry.