Rare earth metal induced modification of gamma-M2C, gamma-M6C, and gamma-MC eutectics in as cast M2 high speed steel

The effects of rare earth metals on the morphology of gamma-M2C, gamma-M6C, and gamma-MC eutectics of as cast M2 high speed steel were investigated. T he solidification of the specimens was monitored by conventional and differ ential thermal analysis and the characterisation of the microstructures was performed through optical and scanning electron microscopy. Rare earth met als favoured the formation of the M6C eutectic, at the expense of the M2C e utectic, and promoted the formation of the duplex M2C/MC and M6C/MC eutecti cs. The formation? of these duplex eutectics was attributed to the decrease in the MC eutectic temperature.