The role of inoculant on grey cast iron (GCI) and impact on microstructure and mechanical properties

¹ University of Witwatersrand, Faculty of Engineering, School of Chemical and Metallurgy
² Advanced Materials Division, Mintek, 200 Malibongwe Drive, Randburg, 2194, South Africa

^* Corresponding author: 1431415@student.wits.ac.za

Abstract

This research was conducted to explore the influence of inoculants on the microstructure and mechanical properties of grey cast iron. The study also reviews the literature related to graphite morphology, solidification behaviour, and its impact on mechanical properties. However, inconsistencies in reported work highlight the need for a standardised approach to the inoculation of cast iron. Previous studies reported the successes and limitations of these inoculants on grey cast iron identifying the need to explore alternative inoculants such as FeSi-Zr. This study explores the effect of FeSi75-Zr inoculant on the microstructure, thermal and mechanical properties of grey cast iron. FeSi75-Zr inoculants were added at varying quantities of 0.1%, 0.2%, and 0.4% into grey cast iron materials. Additions of inoculant increased eutectic temperature and promoted the formation of short, sharp graphite flakes within the matrix. Notably, the addition of 0.2% FeSi-Zr inoculant resulted in the most refined microstructure and a hardness value that decreased from 172HV of un- inoculated to 156HV of 0.2% inoculanted. Increasing inoculation content led to an increased ultimate tensile strength (UTS) of 229 MPa.