The role of CPD in the formation of additional subboundaries is not investigated here. In this connection, the change of CPD concentration at multiple martensitic transformations has been studied for the Fe-Mn-based alloys 2, 3, and 4. The concentration of CPD was measured by the relative displacement of austenitic (111)γ and (222)γ reflections [14, 15]. It is apparent that the concentration

of CPD in alloy 3 (forming ϵ′-martensite) does not exceed 0.015 (Figure  4). In this alloy, the austenitic lattice misorientation is insignificant and not accumulated for multiple γ-ϵ′-γ transformations (Figure  3). This means that a small CPD concentration this website does not lead to the formation of additional subgrain boundaries and to the fragmentation of reversed austenite. In alloys 3 and 4, the concentration of CPD exceeds the

magnitudes 0.022 and 0.025, respectively (Figure  4) and austenitic lattice misorientation reached 17° and 6.5°, respectively (Figures  1 and 3). Obviously, starting from this CPD concentration, the disoriented fragments form in the microstructure of reversed austenite. These results show that with the increase of CPD concentration in austenite, the ability to form disoriented fragments of its lattice increases. Figure 4 Concentration of chaotic packing defects α as a function of the number of thermocycles N . 1 – alloy 2, 2 – alloy 3, 3 – alloy 4. Conclusions The γ-ϵ-γ and γ-ϵ′-γ transformations in iron-manganese alloys resulted in a smaller increase of the IWR 1 misorientation angle ψ than that for γ-α-γ transformations in the iron-nickel alloys. This is due to the smaller number of crystal structure defects generated by γ-ϵ-γ transformations. In fact, the dislocation

density of the austenite increases by 3 orders of magnitude after the γ-α-γ transformation, but it is constrained to less than 1 order of magnitude after the γ-ϵ-γ transformation. The misorientation is changed to a still smaller amount during γ-ϵ′-γ transformations. Thus, the sequence of the magnitude of the misorientation Vasopressin Receptor angle ψ during martensitic transformations in iron-based alloys can be described as Accumulation of the dislocations at multiple f.c.c.-b.c.c.-f.c.c. martensite transformations in iron-nickel alloys led to full recrystallization of austenite due to the formation of lattice fragments with significant mutual misorientation and to a transformation of the single-crystalline sample into a polycrystalline one. Multiple f.c.c.-h.c.p.-f.c.c. martensite transformations in iron-manganese alloys, on the other hand, led to the formation of additional subgrain boundaries in austenite by accumulation of CPD up to a magnitude exceeding 0.02. A full recrystallization of austenite at multiple f.c.c.-h.c.p.-f.c.c. and f.c.c.-18R-f.c.c. transformations was never observed. Acknowledgements The authors thank Dr. P.