|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Advanced Characterization Techniques for Quantifying and Modeling Deformation
||Structural Analysis of In-field Loaded Railway Steel
||Roumen Petrov, Jun Wu, Loic Malet, Stephan Godeth, Jilt Sietsma
|On-Site Speaker (Planned)
Structural changes on the surface of R260Mn grade rails, developed during wheel/rail contact, were investigated by optical microscopy, electron backscatter diffraction (EBSD), transmission Kikuchi diffraction (TKD) in scanning electron microscope (SEM) and automatic crystal orientation mapping in transmission electron microscope (ACOM-TEM). The microstructures of the heavily deformed surface layer known as white etching layer (WEL) and the deformed under layer were characterized in different length scales. Grain fragmentation and refinement of ferrite are characterized by all applied methods as well as grain alignment towards traffic direction. Substructures, having misorientation lower than 5°, are identified by analysing the local misorientation maps (kernel average misorientation (KAM)). Retained austenite was detected in the WEL by EBSD, TKD and ACOM. Detection of retained austenite and ultrafine grain structure were considered as an indication for mixed mechanism of formation of the WEL where both martensitic transformation and severe plastic deformation take place.
||Planned: EPD Congress Volume