Print Email Facebook Twitter Micro and nanoscale characterization of complex multilayer-structured white etching layer in rails Title Micro and nanoscale characterization of complex multilayer-structured white etching layer in rails Author Wu, J. (TU Delft (OLD) MSE-3; Universiteit Gent) Petrov, R.H. (TU Delft (OLD) MSE-3; Universiteit Gent) Kölling, S. (Eindhoven University of Technology) Godet, Stephane (Vrije Universiteit Brussel) Sietsma, J. (TU Delft Materials Science and Engineering; TU Delft (OLD) MSE-3; Universiteit Gent) Department Materials Science and Engineering Date 2018 Abstract Micro- to nano-scale characterization of the microstructures in the white etching layer (WEL), observed in a Dutch R260 Mn grade rail steel, was performed via various techniques. Retained austenite in the WEL was identified via electron backscatter diffraction (EBSD), automatic crystallographic orientation mapping in transmission electron microscopy (ACOM-TEM), and X-ray diffraction (XRD). EBSD and ACOM-TEM methods were used to quantify grains (size range: 50 nm–4 μm) in the WEL. Transmission electron microscopy (TEM) was used to identify complex heterogeneous microstructural morphologies in the WEL: Nano-twinning substructure with high dislocation density in the WEL close to the rail surface and untransformed cementite and dislocations in the WEL close to the pearlite matrix. Furthermore, atom probe tomography (APT) revealed a heterogeneous through-thickness distribution of alloying elements in the WEL. Accordingly, the WEL is considered a multi-layered martensitic microstructure. These findings are supported by the temperature calculations from the shape analysis of the manganese profile from APT measurements, related to manganese diffusion. The deformation characteristics of the WEL and the pearlite beneath the WEL are discussed based on the EBSD measurements. The role of deformation in the martensitic phase transformation for WEL formation is discussed. Subject white etching layerrailsmartensitetemperaturephase transformationplastic deformationOA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:9c8cafe6-1e97-4f1b-916a-b40594965222 DOI https://doi.org/10.3390/met8100749 ISSN 2075-4701 Source Metals, 8 (10) Part of collection Institutional Repository Document type journal article Rights © 2018 J. Wu, R.H. Petrov, S. Kölling, Stephane Godet, J. Sietsma Files PDF metals_08_00749.pdf 2.29 MB Close viewer /islandora/object/uuid:9c8cafe6-1e97-4f1b-916a-b40594965222/datastream/OBJ/view