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

Abstract

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 2.6GPa perpendicular to the rolling direction, although around 2GPa along the rolling direction. Even while such high strength, moderate plastic elongation over 5% was attained.