3D Microstructural Effects in Biphasic Steel Cutting

A three dimensional (3D) fully coupled thermal-mechanical analysis is presented in order to evaluate the influence of certain cutting parameters as well as dual phase microstructure on the orthogonal micro cutting process of steels (in particular, AISI 1045 steel), for which the size of heterogeneities is of the order of magnitude of the uncut chip thickness and tool edge radius. The simulated microstructure is composed of successive hexagonal close-packed layers with grain size control allowing to reproduce the desired fraction volume of the two considered constituents. Based on Johnson-Cook failure criteria inside the constitutive phases and a cohesive zone model along their interfaces, the numerical model is able to take into account both intra and inter granular damage initiation and evolution. Through an analysis of variance (ANOVA) method, a systematic study of the 3D microstructural effects and the relative effect of the pearlite-ferrite phases with respect to cutting settings (cutting speed, tool rake angle and tool radius) is carried out. Key-Words: Micro-cutting, FEA, Inter/intra granular damage, 3D microstructure modeling