Microstructural Evolution of Gas Atomized Fe-25Cr-3. 2C Alloy Powders

The microstructural evolution of the gas atomized Fe-25Cr-3. 2C powders was investigated by using optical microscope, scanning electron microscope, and X-ray diffraction. The experimental results showed that the atomized Fe-25Cr-3. 2C powders were mainly composed of austenite and (Fe, Cr)7C3 carbide. Eutectic microstructure was developed in the larger particles, whereas dendritic microstructure was obtained in the particles with diameter less than 38 μm. The reason for microstructure change should be the difference of nucleation undercooling for particles.