Quantification of complex-phase steel microstructure by using combined EBSD and EPMA measurements

Journal Article · Wed Aug 15 04:00:00 EDT 2018 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2018.05.038· OSTI ID:22805079

Li, Xiaoxiao ^[1]; Ramazani, Ali ^[2]; Prahl, Ulrich ^[1]; Bleck, Wolfgang ^[1]

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1. Steel Institute, RWTH Aachen University, Aachen 52072 (Germany)
2. Department of Mechanical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139 (United States)

Highlights: • In CP800 steel, bainite is the dominant phase with a typical lath (width 300 nm) structure and cementite precipitates. • Martensite is dispersed as small islands and only a few narrowed martensite bands are observed which has been induced by annealing process of cold rolled sheet. • The precise carbon content is measured in bainite and martensite utilizing EPMA line scans, which is around 0.2 wt% and 0.4 wt%, respectively. • Digitalization of the microstructure for CP800 is achieved by combining EBSD and EPMA techniques. • The final constituent map consists of plenty of microstructural features including topography, crystal structures, orientations and elemental distribution. - Abstract: We combined electron backscatter diffraction (EBSD) and electron probe microanalysis (EPMA) techniques to characterize the microstructure of industrial produced complex-phase CP800 steel. First, three major constituents (ferrite, martensite and bainite) are characterized. Then, transformation-induced dislocation zones in ferrite and bainitic regions consisting of different sub-structures are quantified and segmented. A final digitalized component map including plenty of microstructural features including crystal structures, orientations and elemental distribution are successfully achieved. The precise carbon content is measured in bainite and martensite utilizing EPMA line scans, which is around 0.2 wt% and 0.4 wt%, respectively. In the bainite phase of CP800, a typical Bagaryatski orientation relationship between cementite and lath-like bainitic ferrite is revealed based on the select diffraction patterns of transmission electron microscopy measurements.

• OSTI ID: 22805079
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 142; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
BACKSCATTERING
CEMENTITE
DISLOCATIONS
DISTRIBUTION
ELECTRON DIFFRACTION
ELECTRON MICROPROBE ANALYSIS
MARTENSITE
MICROSTRUCTURE
PRECIPITATION
STEELS
TRANSMISSION ELECTRON MICROSCOPY