The characterization of the high-temperature austenitic phase is of great value to understand and control the microstructure evolution during the production of most grades of steels. Unfortunately, the direct observation of the austenitic phase can only be done at elevated temperatures which requires very specialized in-situ equipment like Electron Backscatter Diffraction (EBSD) with a hot stage. Moreover, such sophisticated measurements are always done under simulating laboratory conditions, which are not necessarily representative of the real process.
Alternatively, the reconstruction of Orientation Image Mapping (OIM) is an indirect method of observation which uses data obtained with standard EBSD equipment to virtually recreate the OIM of the prior austenitic phase. In this work we will present two methods aiming to improve OIM reconstruction. The first one is an fully automated algorithm to determine the experimentally observed Orientation Relationship (OR) using the intra-granular misorientation distribution of the entire scanned area. The second algorithm reconstructs the parent phase using a Markov clustering technique that identifies groups of closely related grains based on their angular deviation of the OR.