Analysis and solution of good and bad effect of metal laser cutting

The use of laser to cut sheet metal is gradually becoming popular in the processing industry. Most users compare the four measurement indicators of the incision and section (the width of the incision/kerf, the inclination of the incision, the sag of the incision, and the roughness of the cutting surface). Familiar, but little attention or knowledge of other quality metrics. The quality requirements of cutting are not only the quality of the incision, but also have certain requirements in other aspects, which are mainly measured from three aspects: cutting section, cutting shape and precision, metal structure and strength. The author analyzes three aspects of the evaluation project of cutting quality based on years of experience, hoping to help colleagues.

cut section

As one of the evaluation criteria for cutting quality, the cutting section mainly takes the section roughness, slag hanging, pull-down line, discoloration, and notch as important reference indicators (Table 1). Common defects (Table 2) include natural/abnormal combustion, low-speed/high-speed slag hanging, and incomplete cutting. The reasons for these phenomena are mainly related to the output power of the machine tool, gas purity, and material surface state (Table 3). This paper illustrates the roughness in various situations during the cutting process by exemplifying the specific manifestations of roughness (Table 4) and the surface roughness of 304 stainless steel with a thickness of t=10mm for N2 cutting (Table 5). The roughness of a certain section is also divided into upper, middle and lower parts. For example, when a carbon steel plate with a thickness of t=12mm is cut by O2, the upper Ru of the cutting section is 12-13 μm, and the middle Rm is 19-20 μm. , the lower Rl of 25 ~ 26μm. In general, the effect of high-frequency pulse low-speed cutting is better than CW (continuous wave) high-speed cutting, and it is easier to obtain good cutting surface roughness