Crystallization of FeC Iron Monocarbide During Peritectoidal Transformation of the Lamellar Eutectoid of Ledeburite White Eutectic Cast Iron

Abstract

The previously unknown process of homogeneous and heterogeneous crystallization of FeC iron monocarbide and its co-crystallizations with ε-carbide Fe2C from a supersaturated solid solution based on ε-carbide Fe2C or polycarbide quasi-eutectic formed in the process of peritectoid decomposition during prolonged heating (isothermal annealing) of the lamellar eutectoid ledeburite in cast eutectic white iron has been investigated. Crystallization of 2D monolayers of FeC monocarbide allotropes in the form of translucent extended and elastic crystalline nanofilms has been experimentally proved. The carbide phases in white cast iron can be characterized as a single isomorphic and isostructural quasi-carbide solid solution, which structurally crystallizes as a mixture of carbide phases as a quasi-eutectic, in which the carbon content is free to vary widely without indentification of the carbide phases proper. The decomposition product of the lamellar eutectoid as a result of peritectoid transformation during isothermal annealing is polycarbide with a gradient crystal lattice of solid solutions corresponding in carbon concentration to this or that carbide.