Experimental study of phase transformation in non-equilibrium hypoeutectic alloy from the Fe–Cr–Ni–Mo–C system

In the present study, experimental and thermodynamic analysis of phase transformation in hypoeutectic Fe–24Cr–11Ni–4Mo–0.64C alloy is presented. The investigated alloy was synthesized in an arc furnace in high-purity argon atmosphere using suction-casting unit. Chemical composition of the alloy was determined using an optical emission spectrometer. The microstructure was characterized by scanning electron microscopy. Phase composition in as-cast state was analysed by X-ray diffraction and compared with thermodynamic calculations for equilibrium state using Thermo-Calc software. The analysis of phase transformations was conducted by dilatometry and differential scanning calorimetry investigations. It was found that phase composition of the alloy after non-equilibrium solidification (cooling rate ~30 °C s−1) differs significantly from equilibrium state. Critical temperatures of phase transformations in the alloy were determined.