Analysis of four common problems in laser cutting sheet metal parts

Many customers in the sheet metal industry do not know much about the laser cutting machine, so they may encounter various problems in the process of cutting sheet metal parts with laser. The occurrence of these problems often affect the normal operation and cutting quality of the laser cutting machine. Below, we will analyze the common problems and corresponding solutions

1. Cutting and piercing technology

generally, a hole is punched with a punch on the laser stamping compound machine, and then the laser starts cutting from the small hole. However, there are two basic perforation methods for laser cutting machines without stamping device: (1) blasting perforation - the material forms a pit in the center after being irradiated by continuous laser, and then the oxygen flow coaxial with the laser beam quickly removes the molten material to form a hole. Generally, the size of the hole is positively related to the plate thickness, so the blasting hole diameter of the thick plate is large and not round, so it is not suitable to be used on the parts requiring high machining accuracy; (2) Pulse perforation - a small amount of materials are melted or vaporized by high-power pulse laser. Air or nitrogen is often used as auxiliary gas to reduce the expansion of holes due to exothermic oxidation. The gas pressure is lower than the oxygen pressure during cutting. Each pulse laser produces only a small particle jet, which gradually deepens, and it takes only a few seconds to pierce the thick plate. Once the perforation is completed, immediately replace the auxiliary gas with oxygen for cutting. In this way, the perforation diameter is small, and its perforation quality is better than blasting perforation

2. Burr appears in the machined parts when laser cutting carbon steel

generally, the causes and solutions of burr appear in the machined parts: (1) the laser focus position is offset, the focus position is tested and adjusted according to the offset of laser focus; (2) If the output power of the laser is insufficient, it is necessary to check whether the laser generator works normally. If it works normally, observe whether the output value of the laser control button is correct. If it is not correct, adjust it; (3) The cutting line speed is too slow, so it is necessary to increase the line speed during operation control; (4) The purity of cutting gas is not enough, so it is necessary to provide high-quality cutting working gas (5) the machine tool is unstable due to long running time. At this time, it needs to be shut down and restarted

3. Not all laser cutting

reasons for not all laser cutting: (1) the selection of laser nozzle does not match the thickness of processing plate, replace the nozzle or processing plate; (2) The line speed of laser cutting is too fast, so it needs operation control to reduce the line speed

4. Abnormal spark occurs when cutting low carbon steel

this situation will affect the smoothness and machining quality of the cutting section of the machined part. At this time, under the condition that other parameters are normal, the following conditions should be considered: (1) the nozzle of the laser head is seriously worn, and the nozzle should be replaced in time; (2) When there is no new nozzle replacement, the cutting working gas pressure should be increased; (3) If the thread at the connection between the nozzle and the laser head is loose, immediately stop cutting, check the connection state of the laser head and re thread