Nanocharacterisation of precipitates in austenite high manganese steels with advanced techniques: HRSTEM and DualEELS mapping

Electron Microscopy and Analysis Group Conference 2013

Bobynko, J.^1 ; Craven, A.J.^1 ; McGrouther, D.^1 ; MacLaren, I.^1 ; Paul, G.^2

Kelvin Nanocharacterisation Centre, SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom^1

ThyssenKrupp Steel Europe AG, Research and Development, FuE-E Modelling and Simulation, Kaiser-Wilhelm-Straße 100, 47166 Duisburg, Germany^2

关键词: Bulk properties;    Carbide precipitate;    High manganese steel;    Nanoprecipitates;    Niobium carbide;    Scanning transmission electron microscopes;    Spatial resolution;    Vanadium carbides;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/522/1/012031/pdf
DOI  :  10.1088/1742-6596/522/1/012031

来源: IOP

【 摘 要 】

To achieve optimal mechanical properties in high manganese steels, the precipitation of nanoprecipitates of vanadium and niobium carbides is under investigation. It is shown that under controlled heat treatments between 850°C and 950°C following hot deformation, few-nanometre precipitates of either carbide can be produced in test steels with suitable contents of vanadium or niobium. The structure and chemistry of these precipitates are examined in detail with a spatial resolution down to better than 1 nm using a newly commissioned scanning transmission electron microscope. In particular, it is shown that the nucleation of vanadium carbide precipitates often occurs at pre-existing titanium carbide precipitates which formed from titanium impurities in the bulk steel. This work will also highlight the links between the nanocharacterisation and changes in the bulk properties on annealing.