Deformation kinetics of a TRIP steel determined by in situ high-energy synchrotron X-ray diffraction

The microstructure design and the development of predictive approaches exploiting the transformation-inducedplasticity (TRIP) effect require a keen understanding of the kinetics governing the strain-induced martensitictransformation. In this work, in situ high-energy synchrotron X-ray diffraction is applied to track the deformationkinetics of a commercial AISI 301LN metastable austenitic stainless steel in real-time. The kinetics obtained, providingthe behaviour of the bulk material during room temperature tension up to a true strain of 0.3, unambiguouslyreveals the transformation sequence of ε and α′ martensite which is discussed with respect to the evolutionof texture and slip. These results are enhanced with microstructure analysis including electron backscattered diffractionand transmission Kikuchi diffraction. The insights provided shed light on the role of ε during α′ transformationin metastable austenitic stainless steels and show that the latter is triggered by the general activation of slip