Misorientation distribution between martensite and austenite in Fe-31 wt%Ni-0.01 wt%C

We characterized the morphology, substructure and crystallography of lenticular martensite in a Fe-Ni-C alloy by means of electron backscatter diffraction and scanning electron microscopy. Electron backscatter diffraction maps were used to determine the orientation relationship between austenite and martensite across large regions of the microstructure. We employed orientation distribution functions as a statistical representation method for the observed orientation relationships. High-resolution point-to-point scans were used to normalize the effects of the orientation changes in the austenite caused by the plastic deformation during the formation of lenticular martensite. The analysis revealed that most of the transformation in this material follows an orientation relationship close to the one proposed by Greninger and Troiano. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. (AU)