  The dynamical nucleation of martensite in polycrystals is simulated by means
of Lagrange-Rayleigh dynamics with Landau energetics, which is capable of
obtaining the local stress as a result of the interplay of the potential of
transformation and external loadings. By monitoring the patio-temporal
distribution of the strain in response to the local stress, we demonstrate that
the postcursors, high angle grain boundaries and triple junctions act as
favorable heterogeneous nucleation sites corresponding to different loading and
cooling conditions, and predict the phase diagram of the nucleation mode of
martensite.
