Phase Field Modeling of Microstructural Evolution During Intermediate Quenching and Intercritical Annealing of Medium-Carbon Dual-Phase Steels

This study deals with the effect of initial microstructure on final microstructure of medium-carbon dual-phase steels by two different annealing methods. In experimental studies, initial microstructures martensite and ferrite+pearlite annealed at same annealing temperatures and quenched applying different annealing durations. The influence of initial microstructures on microstructural evolution is studied using scanning electron microscope (SEM). The manganese distribution in ferrite and martensite is analyzed by energy-dispersive X-ray spectroscopy (EDS). The experimental study was supported by phase field modeling using Thermo-Calc and Diffusion-Controlled TRAnsformations (DICTRA) softwares. Experimental results showed that dual phase microstructure has inhomogeneity of martensite islands and fibers in ferritic matrix after intermediate quenching. Martensite formation occurred at prior austenite grain boundaries and martensite laths. In the case of intercritical annealing, pearlite regions are transformed to austenite and eventually martensite islands after quenching.