Complex phase quantification methodology using electron backscatter diffraction (EBSD) on low manganese high temperature processed steel (HTP) microalloyed steel

Microalloyed steels are required to have good strength and toughness, properties that are mostly influenced by microstructure and phase distribution in the steel, obtained by controlling the thermomechanical processing. High temperature processing (HTP) Steels, with lower manganese content, has been recently developed in order to reduce segregation, but reduction of Mn decreases the yield strength. In order to understand the relationship between chemical composition, microstructure, mechanical properties and processing parameters, quantitative analysis of the final microstructure is required but identification and quantification of the ferrite microconstituents under optical microscopy or scanning electron microscopy is difficult due to their similarities. The present work presents a methodology for identification and quantification of complex microconstituents on a low manganese HTP steel, subjected to different hot deformation and cooling cycles, by means of electron backscatter diffraction (EBSD). The results showed that the EBSD methodology allowed to identify and quantify different microconstituents in a low manganese HTP steel with similar results as those obtained by point count methodology.