TY - JOUR A1 - Cios, G. A1 - Winkelmann, A. A1 - Nolze, Gert A1 - Tokarski, T. A1 - Rychlowski, L. A1 - Dan, L. A1 - Bala, P. T1 - Mapping of lattice distortion in martensitic steelβ€”Comparison of different evaluation methods of EBSD patterns T2 - Ultramicroscopy N2 - To visualize the varying tetragonal distortions in high carbon martensitic steels by EBSD, two different approaches have been applied on backscattered Kikuchi diffraction (BKD) patterns. A band-edge refinement technique called Refined Accuracy (RA) (Oxford Instruments) is compared with a technique called Pattern Matching (PM), which optimizes the fit to a simulated BKD signal. RA distinguishes between hypothetical phases of different fixed π‘βˆ•π‘Ž, while PM determines a best fitting continuous π‘βˆ•π‘Ž by projective transformation of a master pattern. Both techniques require stored BKD patterns. The sensitivity of the π‘βˆ•π‘Ž-determination was tested by investigating the microstructure of a ferritic steel with an expected π‘βˆ•π‘Ž = 1. The influence of the Kikuchi pattern noise on π‘βˆ•π‘Ž was compared for a single or 40 averaged frames per measuring point, and turned out to be not significant. The application of RA and PM on the martensitic microstructure delivered qualitatively similar maps of π‘βˆ•π‘Ž. The comparison of RA and PM shows that RA is suitably fast and precise during mapping the martensite π‘βˆ•π‘Ž ratio in analyses of high carbon martensite, especially for fast initial surveys. As RA leads quantitatively to higher noise in π‘βˆ•π‘Ž, the PM analysis can be used for higher precision results. KW - EBSD KW - Steel KW - Martensite KW - Tetragonality KW - Strain PY - 2023 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/58158 AN - OPUS4-58158 VL - 253 SP - 1 EP - 11 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany