The function and function of the metal laser cutting machine are very good, but this kind of metal laser cutting machine will also have some difficulties in cutting, and we must pay attention to this point when using it. Next, I will analyze the basic characteristics of metal laser cutting machine when cutting thick plates.

With the rapid development of high-power fiber laser manufacturing technology and the continuous improvement of numerical control technology, the application of fiber laser processing equipment in the metal sheet cutting market is expanding rapidly in recent years. According to the market feedback information, as well as the plate thickness, cutting quality and the price of cutting equipment, the market application groups of sheet metal processing and manufacturing are subdivided, especially the small and medium-sized enterprise users in this field urgently need to cut the metal plate thickness range and the complete set of high-power metal laser cutting equipment with good cutting quality.

Difficulties of metal laser cutting machine cutting thick plate:

1. The slit is too narrow, resulting in increased heat loss. The reduction of cutting speed increases the heat loss in the cutting area. The main form of heat loss is heat conduction. The greater the thickness, the greater the heat conduction loss and the lower the cutting speed. The material removal at the bottom of the cut becomes inconsistent, although the laser penetrates the thick plate, and a large amount of slag is stuck at the bottom. The formation of slagging is caused by the low average cutting temperature at the bottom of the cut, and the low temperature is due to the large energy loss. In this case, the cut quality is usually not high.

2. The diameter of optical fiber laser spot is small, and the depth of focal length is limited. Although the optical fiber laser can maintain a high laser power density in the cutting depth when cutting metal medium and thick plates, it is not conducive to cutting and slag removal due to the small beam diameter and thin cutting seam. This puts forward higher requirements for the mode of optical fiber laser and the collimation, shaping and range of light spot, and also brings greater difficulties to the process quality of optical fiber laser cutting metal medium and thick plates.

3. Effect and influence of auxiliary gas quality and pressure. Take oxygen as an example; Oxygen plays an important role in cutting medium and thick carbon steel plates by optical fiber laser. The laser is incident on the surface of the workpiece to form a small hole. When the laser beam moves along the cutting direction, there are oxide melts around the small hole and the cutting seam. The purity and pressure of oxygen have a great impact on laser cutting. If there are many impurities and the pressure is not appropriate, the oxygen can not provide enough energy to the bottom of the cut to form a highly liquid melt, thus reducing the cutting quality and cutting speed. By measuring the quality and pressure of auxiliary gas at different slit positions, it is found that the narrower the slit is, the worse the effect of auxiliary gas is, and the more difficult it is to maintain the cutting quality. Therefore, it is very important to ensure proper slit width, auxiliary gas quality and air pressure control for the effect of cutting quality.

4. The difference of geometric shape makes the cutting quality of inflection point decrease. When laser cutting thick plates, the inclination of the melting front becomes prominent, which will lead to the reduction of the laser absorption coefficient of the material, thus ensuring the cutting quality by increasing the cutting power and reducing the cutting speed.

Metal laser cutting machine will be widely used in the cutting field because of its high light point conversion rate, high cutting accuracy, flexible processing ability, good cutting quality and adaptability. In addition, through continuous research on high-performance fiber lasers, development of advanced optical cutting methods and supporting devices, and search for good cutting parameters under various cutting conditions to improve cutting safety, fiber laser cutting will be more widely used, and truly achieve efficient, energy-saving and precise cutting.

These are some basic difficulties of the metal laser cutting machine when cutting the rear thick plate. After you understand these difficulties, it will be easier to operate the metal laser cutting machine.