with Hv0= 1700 MPa and k= 3900 MPa in Fig. 1, which shows good correspondence
between the experimental and calculated values.
The microstructural evolution in the Fe–17Mn–1.5Al–0.3C austenitic
TWIP steel during cold rolling has been described in detail elsewhere
[9]. The regularities of structural changes and their dependence on
cold rolling strain can be briefly summarized here as follows. The dislocation
density drastically increases to values above 1015 m−2 at an early
cold working. A feature of the cold working behavior of the present steel
is the pronounced multiple deformation twinning (Fig. 2a). The number
of deformation twins increases during cold rolling, resulting in rapid decrease
in the twin boundary spacing to its saturation on the level of 20–
30 nm during processing to a total strain of about 0.5. Further cold
rolling to large strains is accompanied by the development of microshear
banding (Fig. 2b to d). The density and thickness of micro-shear
bands increases with straining. The deformation microstructures that
develop at large strains consist of twin/matrix nano-lamellar islands
surrounded by micro-shear bands, which evolve in a spatial network
throughout the rolled steel samples.