LASER CUTTING OF THIN SHEET CARBON STEEL FOR AUTOMOTIVE INDUSTRY

The article is devoted to the development of laser cutting technology of parts of passenger vehicles from carbon steel sheet. It is established that the most successful technological method of laser cutting of automotive low-carbon steel sheets RP153-780B (δ=1.2 mm) is the use of an air-oxygen mixture in a ratio of 1:1, supplied with a pressure of not less than 0.4 MPa, which allows at a process speed of not less than 150 m/h to obtain a cutting surface with a roughness of the order of Ra 12.5 microns and a minimum (about 0,1 mm) grate under the conditions of continuous radiation of a disk laser with a power of 600...650 W. Increasing the pressure of the cutting gas can increase the speed of laser cutting, but this can lead to an increase in the roughness of the edges. This undesirable effect is also caused by the lack of radiation power and an increase in the gap between the cut of the cutting nozzle and the cut sheet. One way to improve the quality of the cut edges is to eliminate the occurrence of autogenous effect associated with the presence of oxygen in the cutting gas. Another innovative approach to quality improvement combined with a reduction in the cost of the process can be the replacement of laser cutting with hybrid laser-plasma cutting