Work

Influence of B and Cu on microstructure and eutectoid transformation kinetics in spheroidal graphite cast iron

Year: 2025

Type: article

Abstract: The influences of B and Cu on the morphology of nodular graphite and fraction of ferrite in spheroidal graphite iron (SGI) have been studied. It was observed that B promotes ferrite in a fully pearlitic SGI alloyed with Cu and Mn. The carbon rejected from the matrix during the ferrite growth was deposited on the graphite nodules as sharp graphite protrusions. Alloying with more Cu proved to be an inefficient way of increasing the pearlite fraction in B-contaminated SGI. Transmission electronmicroscopy (TEM) showed that Cu is enriched at the graphite-ferrite interface. B is detected at the graphite-iron interface, and possibly within the outermost layers of the nodules, using microprobe analysis. In-situ synchrotron X-ray experiments were conducted to analyze the eutectoid transformation kinetics. It shows that both B and Cu retards the eutectoid phase transformation kinetics when they are added individually. However, B accelerates the kinetics in alloys where Cu is present.

Source: Materialia

DOI: 10.1016/j.mtla.2025.102511