For 60% cold-rolled samples with further isothermal annealing a progressive decrease of Ms starts at about 500 °C. Hc presents a peak behavior in the range 500–800 °C and reaches its maximum at 600 or 700 °C, depending on the annealing time. These results are similar to the ones found for the stepwise annealed samples in the post mortem condition. In correspondence to the peak behavior in Hc, an increase in the MR/Ms ratio was also verified. Both characteristics of Hc and MR/Ms indicate the fragmentation of martensite during its reversion. From the MR/Ms behavior it has been noticed that drastic changes occur in the microstructure at 700 °C for very short times (∼5 min). From