Research on Roughness and Microhardness of C45 Material Using High-Speed Machining

From the point of view of production, it is of fundamental importance to know the cutting parameters at which the new surface of the component was created because only in this way is it possible to understand the nature and properties of the created surface. Based on the information obtained, it is then possible to improve the processes used or to create machined surfaces with, if not zero, at least a minimum number of flaws. The main purpose of the article is to create a comprehensive overview of the behavior and properties of the selected material with a focus on the prediction of roughness depending on the cutting speed and depth of cut, Vickers microhardness evaluation, assessment of cutting tool wear, and assessment of the shape and structure of the resulting chip. The achieved results are recorded in graphical and verbal form, from which the necessary conclusions are drawn. From the performed analyses, a mathematical prediction of determining the quality of the machined surface was created, which reflects changes in roughness depending on the cutting speed in the three modifications (700 m/min, 1400 m/min, and 2000 m/min). Conclusions were also drawn regarding the characteristics of the resulting chip and the wear of the cutting edges depending on the change in cutting speed. The fluctuating course of surface roughness when changing the cutting speed can be considered a significant finding—at 1400 m/min, the surface roughness was expected to have a decreasing tendency; however, it increased; a decreasing tendency was not recorded until at speeds of 1800 m/min, but during this process, the material already crept.