Material parameter optimization for orthogonal cutting simulations of AISI4140 at various tempering conditions

The mechanical parameters of quenched and tempered AISI4140 and the machining process characteristics are depending on the material’s tempering state. The process characteristics of practical relevance are not only the cutting forces and the tool wear, but also the surface layer states of the machined part. In order to predict and to improve these characteristics efficiently, chip forming simulation via finite element method (FEM) is commonly applied. However, an issue in machining simulation which is often addressed is choosing appropriate material parameters for the flow stress model. This especially accounts for AISI4140 with various tempering conditions, as in many cases the precise heat treatment is not supplied in detail, even in scientific literature. In this work, orthogonal cutting of AISI4140 with tempering temperatures of 300°C, 450°C and 600°C is investigated by experiments and FE simulations. The Johnson-Cook flow stress model is used in the FE simulation. The referring material parameters for the tempering conditions are iteratively adapted via numerical optimization to fit experimental cutting forces. The obtained parameters are compared to literature values in order to prepare a common ground for the cutting simulation of AISI4140. This contributes to an enhanced process modelling when machining AISI4140 with use-case adapted heat treatments