Martensite formation during incremental cooling of Fe-Cr-Ni alloys: An in-situ bulk X-ray study of the grain-averaged and single-grain behavior

Abstract The formation of martensite (e and α ′ ) in metastable austenitic Fe-18Cr-(10-11.5)Ni alloys was investigated in-situ during cooling. High-energy X-rays were used to study the bulk of the alloys. Both grain-averaged and single-grain data was acquired. e played an important role in the formation of α ′ with an indistinguishable difference in the martensite start temperature. The single-grain data indicated that stacking faults appear as precursors to e. An analogy can be made with deformation-induced martensitic transformation, where the generation of nucleation sites would significantly lower the driving force required to overcome the energy barrier in low stacking fault energy Fe-Cr-Ni alloys.