Morphological variants of carbides of solidification origin in the rapidly solidified powder particles of hypereutectic iron alloy

The paper deals with the analysis of the morphological variants of solidification microstructures and vanadium rich M4C3 carbide phases in the rapidly solidified (RS) powder particles from hypereutectic Fe–C–Cr–V alloy prepared by the nitrogen gas atomisation. Five main types of solidification microstructures were identified in RS particles: microstructure with globular carbides, microstructure with globular and star-like carbides, microstructure with primary carbides in the centres of eutectic colonies, microstructure with eutectic colonies without primary carbides and microstructure with eutectic spherulites. Based on the morphological features of carbide phases and the thermal history of RS particles, the microstructures were divided into two groups—microstructures morphologically affected and non-affected during the post-recalescence period of solidification. Thermophysical reasons for the morphologically different M4C3 carbide phases development in the RS powder particles are discussed.