High resolution EBSD characterization of the phase transformations and orientation relationships in ultra high performance steels

摘要

In recent years, TRIP and TWIP steels have drawn the attention of many researchers, mainly because of their exceptional mechanical properties that render them very attractive to the automotive industry. Their large elongations and high work-hardening rates originate from twinning (Twinning-lnduced Plasticity) or from the dynamic transformation of austenite into martensite (TRansformation Induced Plasticity). Full-TRIP steels consist of an initial fully austenitic microstructure, whereas multiphase TRIP steels consist of a ferrite-based matrix and retained austenite, typically around 10-20 percent , This study deals with the use of state-of-the-art high resolution orientation imaging techniques to characterise the orientation relationships (ORs) holding governing the different phase transformations taking place during processing or straining of ultra-high performance steels.