Analysis of the Surface Stereometry of Alloyed Austenitic Steel after Fibre Laser Cutting using Confocal Microscopy

The paper extends the concept of cut edge quality and examines the fibre laser cutting process. A Prima Power Platino Fiber Evo device with a reference speed (RS) of 3500 mm/min was used for laser cutting. In order to analyse the influence of the laser cutting speed on the cut edge quality of X5CrNi18-10 stainless steel sheets, macroscopic studies were conducted on a stereoscopic microscope and surface stereometry on a confocal microscope. The obtained results were analysed to evaluate 2D and 3D parameters. These parameters make it possible to determine the cut edge quality and the susceptibility to the application of protective coatings. It was observed that the value of the Sa parameter is the highest for a cutting speed equal to 130% of RS. The Sz parameter is similar, while the Sk, Spk and Svk parameters rise as the speed increases, which is a negative phenomenon. Comparative tests were also conducted for four specimens made at cutting speeds of 70%, 85%, 100% and 115% of RS, respectively. It was found that the laser cutting speed has a significant impact on the cut edge quality and that stainless steel can be cut while maintaining the technological regime at 115% of RS.