Effect of titanium on the morphology of primary M7C3 carbides in hypereutectic high chromium white iron

This paper studies the effect of titanium concentration on the morphology of primary M7C3 carbides in hypereutectic high chromium white cast iron by means of the optical microscopy (OM), the scanning electron microscopy (SEM), the X-ray diffraction (XRD), the energy dispersive X-ray spectrometry (EDS) and Leica image analyzer. Theoretical calculation shows that solute Ti atoms can react with carbon and form TiC particles under certain conditions in the melt of hypereutectic high chromium cast iron. The experimental results show that the morphology of primary M7C3 carbides can be improved by adding a suitable amount of Ti. This improvement correlated with the emergence of TiC particles. These particles can act as the substrates for heterogeneous nucleation of primary M7C3 carbides, which results in significant refinement of the final grain size.