The isothermal martensite formation in a maraging steel: A magnetic study

Maraging steels reach their extraordinary final mechanical properties from a combination of a fine martensitic microstructure and a high precipitate density. In the steel studied in this work, the starting metastable austenitic microstructure is transformed isothermally to martensite at 233 K. This work shows how the rate of the isothermal martensite formation in this steel can be significantly increased by an external magnetic field. In situ magnetization measurements have been used to characterize the phase transformation kinetics. A model of mixed physical–empirical nature is presented to support the observations.