The Utmost Thickness of the Cut Sheet for the Qualitative Oxygen-assisted Laser Cutting of Low-carbon Steel

The peculiarity of the laser cutting is its high speed combined with the high quality of the cut surface. The issues, how the cutting speed and cut roughness change with the sheet thickness, and what is the utmost thickness at which the quality is acceptable, are of practical importance. Theoretical models of the laser cutting developed today do not permit answering these questions. In the present work, the task is solved experimentally for the oxygen-assisted laser cutting of low-carbon steel. Under study was the dependence of the cut surface roughness on the cutting speed within the wide range of cut sheet thicknesses. The experiments were carried out with the CO2 laser. The empirical dependencies of the optimal cutting speed (at which the cut surface roughness is minimal) on the sheet thickness are found. It is demonstrated that there is the utmost thickness of 40...50 mm, and above it the qualitative cutting is impossible. The obtained results are compared to the similar ones obtained for the fiber laser.