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Quantitative analysis of martensite and bainite microstructures using electron backscatter diffraction
Author(s) -
Wang Yongzhe,
Hua Jiajie,
Kong Mingguang,
Zeng Yi,
Liu Junliang,
Liu Ziwei
Publication year - 2016
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.22703
Subject(s) - bainite , electron backscatter diffraction , martensite , microstructure , materials science , electron diffraction , diffraction , backscatter (email) , crystallography , metallurgy , optics , physics , chemistry , computer science , telecommunications , wireless
In the present work, ultra‐high‐strength steels with multiphase microstructures containing martensite and bainite were prepared by controlling the cooling rate. A new approach was proposed for quantitatively statistical phase analysis using electron backscatter diffraction (EBSD) based on the band contrast which correlates to the quality and intensity of the diffraction patterns. This approach takes advantage of the inherently greater lattice imperfections of martensite, such as dislocations and low‐angle grain boundaries, relative to that of bainite. These can reduce the intensity and quality of the EBSD patterns of martensite, which decrease the band contrast. Thus, combined with morphological observations, Gaussian two‐peak fitting was employed to analyze the band contrast profile and confirm the ranges of band contrast for the two phases. The volume fractions of bainite and martensite in different samples were determined successfully. In addition, the results show that increased cooling rates improve the proportion of martensite and the ratio of martensite to bainite. Microsc. Res. Tech. 79:814–819, 2016 . © 2016 Wiley Periodicals, Inc.