Fundamental Achievements of the Dynamic Theory of Reconstructive Martensitic Transformations

Abstract

Basic directions in the theory of martensitic transformations are briefly listed. Solutions of several important problems in the context of dynamic theory of reconstructive martensitic transformations are reviewed. The FCC-BCC (BCT) transformation in iron alloys is used as an example. Main attention is paid to concept links. In particular, the key role of the concept of initial exited state for realization of transformations with crystal growth at supersonic speed is shown. The leading value of this concept both for calculation of critical rates of austenite cooling and for estimation of scales of incubatory times at bainitic transformation is marked as well.

Dynamic Model of the B2 → B19′ Martensitic Transformations Taking into Account an Intermediate Mesoscopic State

“…The Λ → Λ′′ transition is accompanied by deviations of the wave normals and the (22 3 ) B2 → (0.48 0.39 0.78 ) B2 change of the habit plane. Hence there are grounds to believe that during the B2 → IMS → B19′ transformations there are actual possibilities for dynamic control over the martensite crystal growth [10][11][12][13] started in elastic fields of dislocations genetically related to the B2 → IMS structural rearrangement.…”

The rules for selection of dislocation nucleation centers of martensite in the dynamic theory of reconstructive martensitic transformations

“…напр. [1][2][3][4]). В рамках этой парадигмы вместо традиционного представления о квазиравновесных зародышах (приемлемого для медленно протекающих превращений) вводится понятие начального возбужденного состояния (НВС), возникающего в упругих полях дислокационных центров зарождения (ДЦЗ).…”

Crystons: basic ideas and applications

“…SIM is realized under the action of the external elastic stress field σ, in a temperature range of M s <T<М sσ , where М sσ corresponds to the temperature of the MT start during cooling in case σ is equal to the elastic limit. SIM does not differ in principle from CIM, since the wave mechanism for controlling the growth of separate martensite crystals [27][28][29][30] is similar. Therefore, the influence of external stress decreasing the symmetry of the system (crystal plus the external field) comes down to a reduction (in comparison with CIM) of the number of the observed martensite reaction variants.…”