Rare earth metal induced modification of γ-M2 C, γ-M6 C, and γ-MC eutectics in as cast M2 high speed steel

Abstract

The effects of rare earth metals on the morphology of γ-M2 C, γ-M6 C, and γ-MC eutectics of as cast M2 high speed steel were investigated. The solidification of the specimens was monitored by conventional and differential thermal analysis and the characterisation of the microstructures was performed through optical and scanning electron microscopy. Rare earth metals favoured the formation of the M6 C eutectic, at the expense of the M2 C eutectic, and promoted the formation of the duplex M2 C/MC and M6 C/MC eutectics. The formation of these duplex eutectics was attributed to the decrease in the MC eutectic temperature.