Modeling of the workpiece geometry in turning of hardened steel

摘要

In turning of hardened steel, strong forces and high temperatures occur during the cutting process due to the great hardness of the workpiece material, leading to elasto-mechanical and thermo-elastic deformations of system elements. These deformations superimpose and cause displacement between cutting edge and workpiece, resulting in form and dimensional deviations of the workpiece after machining. By means of developed models and simulations for determining the elastic deformations of system elements and models describing the displacement of cutting edge due to wear and due to the machine set-up, the resulting form and dimensional deviations can be calculated as a function of the cutting conditions. The results are compared with experimentally determined form and dimensional deviations of the workpiece in turning the hardened steel AISI 4140 with the cutting tool material polycrystalline cubic boron nitride (PCBN). By means of the calculated results, workpiece deviations can be minimized by selecting optimal cutting conditions already during process design.