Nanoscale compositional fluctuations enabled by dynamic strain-induced austenite reversion in a Mn-rich duplex steel

Abstract The solute partitioning under dynamic strain-induced austenite reversion in a Fe-11Mn-1Al-0.07C (in wt.%) steel was studied by atom probe tomography. It was found that the concentrations of Mn and Al fluctuate in austenite at the nanoscale during warm deformation at 650 °C, leading to less stable chemical zones. It is proposed that stored energy in ferrite can change the thermodynamic equilibrium, leading to the formation of austenite with lower Mn and higher Al contents. This paper reveals evidence that stored strain can deviate the thermodynamic equilibrium, and hence could be a new path for engineering the nanostructures in austenite.