Isothermal martensitic transformation in Fe-Ni and Fe-Ni-C alloys at subzero temperatures

Kinetics of anomalous multi-step formation of lath martensite in steel

“…Furthermore, it is limited to martensite with lath morphology and therefore cannot explain the wavy transformation curves in Refs. [11,30,[39][40][41], where lenticular martensite was observed.…”

“…[30,39], where a controlled timedependent multi-step transformation of austenite into lenticular martensite was reported after a single large transformation burst in Fe-Ni-C systems. The mechanism responsible for irregular behaviour was not described in Refs.…”

“…[11,30], anomalous observations were reported where the steps appear smoothed into a train of retardations and accelerations of the transformation, such that the kinetics of the transformation was characterized by a series of transformation rate maxima. Specifically, multiple retardations and accelerations of the transformation during continuous cooling have been reported several times for the transformation of face-centred-cubic (fcc) austenite into body-centred-cubic (bcc) microstructure constituents in steels, as ferrite [31][32][33][34], bainite [35] and martensite with lath [36][37][38] and lenticular morphology [11,30,[39][40][41], respectively.…”