Akademik Veri Yönetim Sistemi
INTERNATIONAL JOURNAL OF METALCASTING, cilt.16, sa.4, ss.1836-1848, 2022 (SCI-Expanded)
The present study was performed to investigate the influences of short-time austenitization on mechanical properties and transformation-induced plasticity (TRIP) in austempered ductile iron. For this purpose, Cu-Ni-Moalloyed ductile iron (DI) were poured into sand molds and subsequently the DI samples were austenitized at 850 degrees C for the duration of 15-30-60 min followed by holding in a salt bath at an austempering temperature of 260 degrees C for 90 min. Characterization studies were carried out with dilatometer, image analyses software, tensile test, hardness test, XRD analysis, optical and scanning electron microscopies. Findings revealed that as the austenitization time increased, carbon content of austenite (total of high carbon and blocky) and bainitic ferrite cell size enhanced, and phase volume fractions of transformation products of austenite changed. Within this context, changes in the mechanical properties were discussed. Optimum combination of strength and ductility and maximum TRIP effect were determined in the shortest (15 min)-austenitized sample. Accordingly, it was determined 15 min austenitization led to progression in the mechanical properties as 146 MPa and 2.8 % increment in the tensile strength and total elongation respectively, compared to 45 min austenitized sample.