Computational assessment of the microstructure-dependent plasticity of lamellar gray cast iron - Part I: Methods and microstructure-based models

This paper focuses on the microstructure-dependent inelastic behavior of lamellar gray cast iron. It comprises the reconstruction of three dimensional volume elements by use of the serial sectioning method for the materials GJL-150, GJL-250 and GJL-350. The obtained volume elements are prepared for the numerical analyses by means of finite-element method. In the finite-element analysis, the metallic matrix is modeled with an elastic-plastic deformation law. The graphite inclusions are modeled nonlinear elastic with a decreasing value of Young's modulus for increasing tensile loading. Thus, the typical tension-compression asymmetry of this material class can be described. The stress-strain curves obtained with the microstructure-based finite-element models agree well with experimental curves of tension and compression tests. Besides the analysis of the whole volume element, the scatter of the stress-strain response in smaller statistical volume elements is investigated. Furthermore, numerical studies are performed to reduce computational costs.