Observation of Retained γ Grains in TRIP Steels Using SEM-FIB/EBSD Method and Examination of Stability Evaluation Method

Morphologies of retained γ grains in TRIP steels are a very important factor for understanding the relationship between microstructure and mechanical properties steels. We have investigated serial sectioning technique using scanning electron microscope (SEM) equipped with an backscatter diffraction (EBSD) focused ion beam (FIB) to reconstruct 3D In this paper, FIB fabrication condition dependences reconstructed structures presented γ-grains stabilities discussed terms effects. Retained not recognized by EBSD map from fabricated surface normal accelerating voltage 30 kV, because easily transformed into martensite due irradiation. It was found that transformation suppressed low acceleration 7 kV or less, three-dimensional morphology could be observed technique. becomes possible evaluate each phase we proposed evaluation method irradiation transformation.