Print Email Facebook Twitter An in-situ LSCM study on bainite Formation in a Fe-0.2C-1.5Mn-2.0Cr Alloy Title An in-situ LSCM study on bainite Formation in a Fe-0.2C-1.5Mn-2.0Cr Alloy Author Sainis, Salil (Student TU Delft) Farahani, H. (TU Delft (OLD) MSE-3; TU Delft Novel Aerospace Materials) Gamsjäger, Ernst (Montanuniversitaet Leoben) van der Zwaag, S. (TU Delft Novel Aerospace Materials; Tsinghua University) Date 2018 Abstract Direct microscopic observation of the isothermal bainite evolution in terms of nucleation events, the location of the nuclei, as well as their growth is very valuable for the refinement of models predicting the kinetics of bainite transformation. To this aim, the microstructural evolution in a Fe-0.2C-1.5Mn-2.0Cr alloy during isothermal bainite formation at temperatures between 723 K and 923 K is monitored in situ using high temperature laser scanning confocal microscopy (LSCM). Both the nucleation and the growth kinetics of the bainitic plates are analyzed quantitatively. Bainitic plates are observed to nucleate on three different types of locations in the grain: at austenitic grain boundaries, on newly-formed bainite plates and at unspecific sites within the austenite grains. Grain boundary nucleation is observed to be the dominant nucleation mode at all transformation temperatures. The rate of nucleation is found to vary markedly between different austenite grains. The temperature dependence of the average bainite nucleation rate is in qualitative agreement with the classical nucleation theory. Analysis of plate growth reveals that also the lengthening rates of bainite plates differ strongly between different grains. However, the lengthening rates do not seem to be related to the type of nucleation site. Analysis of the temperature dependence of the growth rate shows that the lengthening rates at high temperatures are in line with a diffusional model when a growth barrier of 400 J mol–1 is considered. Subject BainiteGrowthKineticsMicroscopyNucleationPhase transformationSteelOA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:ac2fd73a-d02a-40f6-943f-661e28653e2b DOI https://doi.org/10.3390/met8070498 ISSN 2075-4701 Source Metals, 8 (7) Part of collection Institutional Repository Document type journal article Rights © 2018 Salil Sainis, H. Farahani, Ernst Gamsjäger, S. van der Zwaag Files PDF metals_08_00498.pdf 2.11 MB Close viewer /islandora/object/uuid:ac2fd73a-d02a-40f6-943f-661e28653e2b/datastream/OBJ/view