Phase transformation of austenite during isothermal holding of a high-performance high-manganese steel

A new composition of high-manganese steel with high Mn and low Si steel was studied, evaluating the austenite stability after different heat treating conditions. In order to determine the phase transformations and austenite stability, dilatometry experiments were carried out, and the microstructure was characterized by light optical microscopy, x-ray diffraction, and transmission electron microscopy. For long holding times at 550°C the precipitation of lamellar cementite emerged from the microstructure. For very long treatments at this temperature, epsilon martensite was observed, as a result from the depletion of C by cementite formation and thus the reduction of the austenite stability.