CALCULATION OF FORCES IN THE TURNING OF HARDENED STEELS UNDER HEAVY CUTTING CONDITIONS

Abstract

In the restorative machining of railway wheels, traditional approaches to the determination of cutting conditions based on averaged values of material strength and homogeneity are losing their reliability. This necessitates a transition from global empirical relationships to local, geometrically and physically adaptive models capable of accounting for the spatial heterogeneity of the defect field and the corresponding variability of contact loads along the cutting edge. The study is aimed at developing a thermomechanical model for determining cutting forces during the turning of thermally hardened steels under conditions of increased chip thickness. The present study attempts to develop a model that accounts for the direct effect of multiple factors on cutting forces, as well as the indirect influence of cutting conditions. The developed cutting-force calculation model is of practical significance for the analysis and optimization of surface machining conditions. Due to the specific nature of the interaction between the tool and workpiece material, which de-pends on the geometry of the cutting edge, the physicomechanical properties of the machined material, cutting condi-tions, and the conditions of the cutting-cooling medium, the analytical description of these forces is associated with considerable difficulties. The application of the proposed model will make it possible to optimize cutting conditions and cutting-edge geometry while taking into account the required deviations of the machined profile, significantly faster than traditional methods. This contributes to reducing the time required to transition production to qualitatively new technological requirements. A comparison of the numerical simulation results with experimental data has been per-formed, confirming the adequacy of the proposed approach. The influence of machining conditions and cutting-edge geometry in plan on the components of cutting forces, as well as on the magnitude of elastic-plastic deviations of the machined surface caused by these forces, has been investigated.