Effect of partial remelting temperature on primary phase in semisolid microstructure of hypereutectic high Cr white cast iron

In order to investigate the effect of partial remelting temperature on the morphologies of primary carbides, semi-solid billets of Cr17 hypereutectic high chromium cast iron were remelted for 5 min at 1230°C, 1250°C, 1270°C respectively, and shape factor and grain factor of primary carbide particles were characterized quantificationally via a Leica image analyzer. The results indicate that firstly with an increase in the partial remelting temperature, the shape of the primary carbides undergoes ameliorating, deteriorating and obvious ameliorating in sequence and the size of primary carbides decreases gradually. Secondly, the process of primary carbides evolution is determined collectively by solute diffusion and phase surface tension, however, the action of surface tension is not evident under the lower remelting temperature condition. Finally, the perfect remelting structure would be obtained at 1270°C for 15 min in the investigation.