The Effect of Partial Melting Homogenization on the Mechanical Properties of Thick Section Austempered Ductile Iron Containing 2% Mn
Elements such as Mn and Mo may be added to ductile iron to improve its hardenability and mechanical properties, but segregation of these elements could result in the reduction of mechanical properties and must therefore be considered during the manufacturing of thick section ductile iron. In this research the microstructures of cast specimens containing 2% Mn were studied by optical microscopy and scanning electron microscopy. Results showed that manganese segregates in the intercellular areas while silicon segregates in the regions around graphite nodules. Partial Melting Homogenization (PMH) was carried out on the samples to reduce segregation. Analysis of the results showed that homogenization has been done successfully and segregation in the ductile iron matrix was significantly reduced. The successful effect of homogenization was also studied on austempered samples. PMH prior to austempering resulted in a very uniform bainitic microstructure. Tensile tests were carried out on the samples which showed improved mechanical properties due to combined PMH process and austempering process.
Adel Nofal and Mohamed Waly
A. Sheikholeslam et al., "The Effect of Partial Melting Homogenization on the Mechanical Properties of Thick Section Austempered Ductile Iron Containing 2% Mn", Key Engineering Materials, Vol. 457, pp. 193-198, 2011