Microstructures and deformation behavior of nano-grained and ultrafine-grained high-Mn austenitic steel fabricated by asymmetric-symmetric rolling

Abstract

The nano-grained (NG) high-Mn austenitic steel with average grain size of 60 nm and the ultrafine-grained (UFG) steels with grain size below 500 nm are successfully produced by combination of the asymmetric rolling (ASR) and symmetric rolling (SR) method and the subsequent annealing treatment. The annealed NG steels exhibit relatively higher strain hardening and good balance of strength and ductility, which is attributed to the partial recrystallization of the nanostructures and the relatively lower stacking fault energy of the high-Mn TWIP steel. © Published under licence by IOP Publishing Ltd.