Investigation of Precision Large-Caliber Slot Cutting of Sheet Steel Using Single-Mode Fiber Laser Radiation

We present results of the experimental and theoretical investigation of the characteristics and features of precision large-caliber slot cutting of low-carbon steel sheets with thicknesses up to 10 mm by radiation of 1-kW single-mode fiber laser. Using periodic-pulsed single-mode laser radiation and oxygen as the cutting gas, slots with calibers from 20 to 60 (in some cases – up to 100) and widths up to about 60 microns have been obtained. The cutting speed (50—100 mm/min) was measured and the efficiency of precision cutting (»3%) and efficiency of laser radiation transport in the waveguide mode (»25%) were estimated. The morphology and roughness parameters of the cut surface were determined. Variation of the hardness and phase structure of steel in the direction of normal to the slot wall were studied. A qualitative model of laser oxygen precision slot cutting with deep channeling is proposed.