Unlocking the Secrets of Austenite – Metallographic Detective Work in the Laboratory

Abstract Metallographic examinations using light and electron microscopy, EBSD analysis, and X-ray diffractometry were performed on four steels with different austenite content as part of a materialography student project. The aim was to provide a qualitative and quantitative determination of the austenite content present in each case. Different color etching techniques revealed the microstructure in different contrasts, austenite and delta ferrite phases could be differentiated, and the residual austenite could be determined in overaged steel using light and scanning electron microscopy (SEM). The areas revealed by color etching with a size of only a few μm in the light microscope could be correlated in the SEM and were identified by EBSD analysis.