High-resolution topochemical analysis and thermochemical simulations of oxides and nitrides at grain boundaries and within the grains of a low alloy Mn-Cr hot-rolled steel sheet

[摘要] The selective oxidation underneath the scale layer of an industrially hot rolled Fe-1.8Mn-0.8Cr steel at temperatures between 600 and 700 degrees C has been investigated. The spatial distribution and composition of formed precipitates has been studied by high-resolution topochemical analysis via TEM-EELS and NanoSIMS and revealed heterogeneities in chemical composition, especially along grain boundaries. It could be shown that grain boundary oxides are predominantly composed of aluminium, chromium or silicon oxides/nitrides, surrounded by manganese-rich oxides. Experimental results of phase stability have been compared to numerical simulations, considering the distribution of more than 40 potentially stable oxide-, nitride- and carbide phases, and differences are critically discussed. Crown Copyright (C) 2021 Published by Elsevier B.V.CC_BY_4.0

[发布日期] 2021-09-25

[关键词] A. metals and alloys;C. grain boundaries;C. oxidation;D. atom molecule and ion impact (NanoSIMS);D. thermodynamic modelling