An automated method of quantifying ferrite microstructures using electron backscatter diffraction (EBSD) data

Sachin L Shrestha; Andrew J Breen; Patrick Trimby; Gwénaëlle Proust; Simon P Ringer; Julie M Cairney

doi:10.1016/j.ultramic.2013.11.003

An automated method of quantifying ferrite microstructures using electron backscatter diffraction (EBSD) data

Ultramicroscopy. 2014 Feb:137:40-7. doi: 10.1016/j.ultramic.2013.11.003. Epub 2013 Nov 21.

Authors

Sachin L Shrestha¹, Andrew J Breen², Patrick Trimby², Gwénaëlle Proust³, Simon P Ringer⁴, Julie M Cairney⁴

Affiliations

¹ School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia. Electronic address: sachin.shrestha@sydney.edu.au.
² Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006, Australia.
³ School of Civil Engineering, The University of Sydney, NSW 2006, Australia.
⁴ School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006, Australia.

PMID: 24291695
DOI: 10.1016/j.ultramic.2013.11.003

Abstract

The identification and quantification of the different ferrite microconstituents in steels has long been a major challenge for metallurgists. Manual point counting from images obtained by optical and scanning electron microscopy (SEM) is commonly used for this purpose. While classification systems exist, the complexity of steel microstructures means that identifying and quantifying these phases is still a great challenge. Moreover, point counting is extremely tedious, time consuming, and subject to operator bias. This paper presents a new automated identification and quantification technique for the characterisation of complex ferrite microstructures by electron backscatter diffraction (EBSD). This technique takes advantage of the fact that different classes of ferrite exhibit preferential grain boundary misorientations, aspect ratios and mean misorientation, all of which can be detected using current EBSD software. These characteristics are set as criteria for identification and linked to grain size to determine the area fractions. The results of this method were evaluated by comparing the new automated technique with point counting results. The technique could easily be applied to a range of other steel microstructures.

Keywords: Data analysis; Electron backscatter diffraction; HSLA steel; Niobium.

Publication types

Research Support, Non-U.S. Gov't