Positron Annihilation Spectroscopy Study of Carbon-Vacancy Interaction in Low-Temperature Bainite

Nano-scale investigations of bainitic structures formed at temperatures below 350 °C have shown that the bainitic ferrite lattice is super-saturated in carbon. A high density of intrinsic defects would be playing a part in the carbon-supersaturation levels detected. In this work, the role of C−vacancy complexes on carbon-supersaturation in low temperature bainite is investigated by means of Positron Annihilation Spectroscopy. Results reveal the presence of a significant amount of monovacancies in the structures that plays an important role on the formation of carbon clusters in the ferrite lattice of nano-scale bainitic structures.This research was supported by the Spanish Ministerio de Economia y Competitividad (MINECO) in the form of a Coordinate Project (MAT2016-80875-C3-1-R and ENE2015-70300-C3-2-R); by the Regional Government of Madrid through the programs S2013/MAE-2745 TECHNOFUSION(II)-CM MINECO/FEDER, and S2013/MIT-2862-MULTIMAT-CHALLENGE; and the Research Fund for Coal and Steel under the Contracts RFCS-CT-2015-709607 and RFCS-CT-2016-754070