Improving the quality of processing articles made of low-alloy ferrite-pearlite steels using concentrated laser emission

This article discusses issues related to improving the quality indicators of the surface products of mining industry made from low-alloy steel grade 40Kh. It is noted that the greatest influence on the formation of roughness is exerted by the destabilization of the treatment process, which is accompanied by the occurrence of self-oscillations. To solve this problem developed method of segmented machining. At the first stage, a segmented zone is formed in the surface layer of the workpiece using laser emission in order to modernize the original microstructure. At the second stage, the workpiece with a segmented zone is subjected the machining process. As a result of the machining process is activated the mechanism of reset and short-term reconfiguration of cutting conditions. The system’s response to this mechanics is manifested in a change in the chip formation process, which is confirmed by high-speed video recording. It is found that when cutting 40Kh steel is resulting nucleation, fracture and crushing of continuous chip. This indicates changes in the chip formation process and stabilization of the turning operation. The effectiveness of the proposed method was assessed using the surface roughness parameters Ra, Rz, Rv. The conducted research has shown the following. At the stage of roughing and semi-finish operation, the general condition of the workpiece surface according to standardized roughness parameters improves by 18 % and 29 % respectively. The data obtained allow us to conclude that the application of the method of controlled segmented machining it possible to reduce the number of operations performed.