Modeling gray iron solidification microstructure for prediction of mechanical properties

摘要

In the present paper the influence of different microstructure parameters on the tensile strength of gray iron is shown. It can be concluded that the volume fraction of primary solidified phase and the specific phase interface of free graphitehave a considerable influence on the tensile strength. However, it is difficult to get a unique relationship between the microstructure and mechanical properties under different chemical compositions, nucleation and cooling conditions.A mathematical model is presented for the simulation of cooling and solidification of gray iron. This includes the heat conduction from the solidifying alloy into the mould and the solidification process. Here, the fraction of primary dendrites iscalculated by the Scheil-Equation. During the eutectic crystallization, nucleation and grain growth processes are considered. The development of graphite lamellae morphology inside eutectic grains has been included into the model. Microstructureparameters, which have been calculated for different chemical compositions, nucleation and cooling conditions, are related to corresponding experimentally determined tensile strengths.