Evidence for Suzuki effect in an Fe-Ni-Cr austenitic stainless steel

The widths of extended dislocations in a single crystal of a low carbon Fe-19wt% Cr-12wt%Ni stainless steel were measured after three different treatments. They include deformation at 523 K or 673 K (treatment l), deformation at room temperature (treatment 2) and annealing at 523 K after room-temperature deformation (treatment 3). In-situ thermal cycling experiments were also carried out. The room-temperature value of the width of extended dislocations was the smallest after treatment 2 and the largest after treatment 1. During the in-situ thermal cycling experiment the width decreased with increasing temperature in a reversible manner. These features were explained by assuming that the Suzuki segregation of solute atoms toward the stacking fault ribbon of an extended dislocation is enhanced significantly during deformation at high temperatures.