Abstract
Graphitisation annealing at 680°C of a quenched medium carbon (0.38wt%C) steel with high contents of both Al (1.44wt%) and Si (1.82wt%) has resulted in the formation of graphite nodules ∼2-5µm in diameter in a very short time (∼2 hours). This could potentially improve machinability by an alternative and more commercially viable alloying route to, for example, the addition of lead. The overall graphitisation process involves the dissolution of the Fe3C iron carbide phase (cementite) as well as formation of the graphite nodules. The evolution of microstructure and composition of cementite during the annealing treatment has been studied by analytical electron microscopy, including energy loss spectroscopy (EELS) and energy-filtered transmission electron microscopy (EFTEM) imaging. The formation of a non-graphitic, carbon-rich amorphous phase was identified during the heat treatment. This amorphous phase could be a previously undetected intermediate stage during the overall graphitisation process, the nodular graphite evolving from it.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
