Tensile elongation behavior of fine-grained Fe-C alloys at elevated temperatures

Abstract

The strain rate-stress relationships and creep strengths of F-C alloys with carbon contents from 1.3 to 5.25wt.%C are found to be similar when grain size is similar. The increase of tensile ductility with carbon content below 2.1%C is attributed to a reduction in the case of dynamic grain growth associated with an increase in the number of fine cementite particles, whereas the decrease of tensile ductility above 2.1%C is due to an increase in the number of coarse cementite particles and an increase in the area of cementite/cementite grain boundaries. Superplastic ductility of Fe-C alloys with carbon contents higher than 2.1%C can be significantly enhanced when powder-processing routes are utilized instead of ingot-processing routes.