At cooling rates faster than 140 C/s the transition is to a metastable material known as martensite. Between 35 and 140 C/s the system at room temperature is a mixture of these two materials. The ...

This has been confirmed by other investigators, and our present knowledge of the tetragonal martensite may be briefly summarised as follows. The axial ratio increases from about 1.03 at 0.8 per ...

The micrographs below show the effect of annealing at different temperatures on a sample of Fe - 0.7 wt % C steel in which martensite has been formed by quenching. Because of the low carbon content ...