Atomic redistribution of alloying elements in nanocrystalline austenitic chromium-nickel steels obtained by strong plastic deformation

The fee solid solution of the stable austenitic 12Cr30Ni steels has exhibited segregation during heavy cold-working psi > 80%, T = 24 degrees C), that gives rise to a ferromagnetic component with a Curie temperature close to 128 degrees C, which may be associated with a local increase in the nickel concentration to 40%. The redistribution of the alloying elements induced by cold working is attributed, by analogy with the low-temperature irradiation, to the diffusion of the point defects generated by the deformation, to the sinks (grain or sub grain boundaries,phase interfaces, etc.) so that the sink regions have higher or lower concentrations of elements with different atomic radii. Changes that take place in the matrix during redistribution of the alloying elements are evaluated using the Mossbauer spectroscopy. (C) 1998 Acta Metallurgica Inc.