Heterogeneous nanostructure developed in heavily cold-rolled stainless steels and the specific mechanical properties

Stainless steels were cold rolled to 92% reduction. The microstructure developed in a stable austenitic stainless steel was complicated heterogeneous nanostructure composed of lamellar-twin domains, shear bands and low-angle lamellar boundaries. Cold-rolled duplex stainless steel, however, exhibited more complicated and mixed microstructure where ferritic lamellar and the heterogeneous nanostructure of austenite were alternatively stacked. The heavily cold-rolled stainless steels followed by ageing exhibited marvelous high tensile strength over 2.6 GPa perpendicular to the rolling direction, although around 2 GPa along the rolling direction. Even while such high strength, moderate plastic elongation over 5% was attained.