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Updated: Jun 4, 2026
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Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction
Published on: April 1, 2017
Application of electron backscatter diffraction techniques to quenched and partitioned steels.
Grant Thomas1, John Speer, David Matlock
1Department of Metallurgical and Materials Engineering, Colorado School of Mines, Advanced Steel Products and Processing Research Center, Hill Hall, Golden, CO 80401, USA. gthomas@mines.edu
Summary
Electron backscatter diffraction (EBSD) effectively characterized steel microstructures, identifying retained austenite and distinguishing phases. However, differentiating martensite from ferrite using EBSD proved challenging due to crystal structure similarities.
Area of Science:
- Materials Science
- Metallurgy
- Crystallography
Background:
- Advanced high-strength steels often feature complex microstructures.
- Understanding phase distribution is crucial for optimizing mechanical properties.
Purpose of the Study:
- To evaluate the effectiveness of Electron Backscatter Diffraction (EBSD) for characterizing hot-rolled quenched and partitioned steel microstructures.
- To identify retained austenite, distinguish martensite from ferrite, and detect transition carbides.
Main Methods:
- Gleeble thermal simulations were used to replicate hot-strip cooling practices.
- Electron Backscatter Diffraction (EBSD) was employed for microstructural analysis.
- X-ray diffraction (XRD) was used for comparative austenite fraction measurements.
Main Results:
- EBSD successfully identified the morphology and location of retained austenite, including large pools and thin films.
- Martensite was qualitatively distinguished from ferrite by regions of low image quality, indicative of high dislocation density.
- A disparity was observed between austenite volume fractions measured by EBSD and XRD.
Conclusions:
- EBSD is a valuable tool for identifying retained austenite in complex steel microstructures.
- Distinguishing martensite from ferrite solely by EBSD indexing is limited, but qualitative differentiation is possible.
- Discrepancies in austenite fraction measurements highlight the need for complementary techniques like XRD.
