Then, s is equal to the cooling time from the
metastable liquidus temperature of the c phase to a temperature
where the secondary recalescence is initiated.
Owing to the small difference between the liquidus temperature
of the d phase and c phase, it is reasonable to
approximate s as an interval between the end of the first
and the onset of the second recalescence (i.e. a little bit
larger than its actual value). Suppose s follows the same
law in the whole undercooling range, Figure 3 shows an
evolution of measured s with DT