A round robin EBSD measurement for quantitative assessment of small plastic strain

Abstract

Crystal orientation measurements using electron backscatter diffraction (EBSD) have been utilized to quantify plastic strain. However, detectability and accuracy of quantification of the plastic strain were not clear. In this study, a round robin measurement using deformed Type 316 stainless steel specimens was launched between 11 organizations using the same specimens. The magnitude of induced plastic strain was 0.25%–10.28%. Two kinds of misorientation parameters, the local misorientation and intra-grain misorientation, were quoted as the measure of the plastic strain. The intra-grain misorientation exhibited a clearer correlation with the degree of plastic strain than the local misorientation did. It was found that the EBSD measurement could detect the plastic strain of more than 1%. It was shown that the variation of the misorientation parameters between the organizations largely depended on the accuracy of crystal orientation identification, which was quantified by the background noise Bn. The error could be reduced by applying the smoothing filter. The EBSD measurements were concluded to be capable of quantifying the degree of plastic strain with accuracy of 0.5% for the strain less than 2%.