Fractography and Local Chemical Composition of Light-Spot Surfaces in the Fractures of Axle Steel

摘要

Results are obtained by fractography and by local chemical analysis of the internal surfaces of light spots in the fractures of OS axle steel. The light-spot surfaces correspond to laminar facets; this corresponds to brittle transcrystallite fracture. Nonmetallic inclusions are found in the region of the light spots; these are mainly calcium carbide CaC_2 and ferrous oxide FeO. The presence of such inclusions in the steel is evidently associated with the entrainment of slag in the metal, on account of the increased content of surfactants—calcium carbide and ferrous oxide—in the discharge slag.