New Insights into Carbon Distribution in Bainitic Ferrite

Abstract A number of studies on bainite transformation at low temperature have revealed that bainitic ferrite formed super-saturated in carbon. The most sensible explanation to this is the increased solubility of a tetragonal ferrite lattice, by virtue of synchrotron radiation and X-ray diffraction results, as well as ab-initio calculations. The question is if this increased tetragonality in bainitic ferrite is the result of a disordered distribution of carbon atoms in ferrite or the result of local carbon clustering (ordering) in association with a locally increased tetragonality. This development of carbon-enriched and carbon-depleted zones that leads gradually to the formation of a modulated structure was reported in the early stages of decomposition of martensite. In the present work, new experimental and theoretical results on the distribution of carbon in bainitic ferrite will be shown trying to shed new light on the nature of bainite transformation.

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