| Abstract Scope |
Solution strengthened ferritic ductile irons (SSF-DI) are characterised by improved mechanical properties compared to conventional cast irons, with a microstructure defined by graphite nodules embedded in a ferritic matrix. Cooling to ambient temperature causes microstructural residual stresses due to thermal contraction mismatches and phase transitions. These stresses, concentrated around the graphite nodules, lead to local plastic deformation and potential crack initiation sites. Experimental determination of residual stresses is complex and numerical models are required to accurately predict them and their effect on fatigue performance in cyclically loaded components.
The ICME-based approach developed in this study provides a tool for the determination of local mechanical properties of SSF-DI and contributes to an increase in efficiency in the design of structural components. The approach consists of coupling two FEM models, one to calculate residual stresses as a function of process conditions, considering phase transitions, and a subsequent model to simulate fatigue performance. |