Effects of short-range ordering and stacking fault energy on tensile behavior of nitrogen-containing austenitic stainless steels

The tensile behavior of austenitic stainless steels with different concentration of nitrogen was studied by analyzing deformation microstructure and calculating short-range ordering (SRO) as well as stacking fault energy (SFE). Increasing nitrogen concentration increased SFE and SRO, which affected the tensile behavior. From the early to intermediate deformation stages, the nitrogen addition induced slip planarity and the delay of dynamic recovery, which were brought by the increase of SRO. As a result, work hardening rate (WHR) rose with the nitrogen content at the end of the intermediate deformation stage. On the other hand, the SFE effect was noticeable at higher strain levels. With increasing nitrogen concentration, the formation of slip lines was sup-pressed and dynamic recovery was promoted. Hence, the reduction in WHR was accelerated with the nitrogen addition. When the overall dynamic recovery behavior was assessed with dislocation-density based constitutive modeling, it was found to depend mainly on SRO rather than on SFE. Therefore, the alloy with higher nitrogen content could achieve higher dislocation density and flow stress.

Automated summary

The tensile behavior of austenitic stainless steels with different nitrogen concentrations was studied. Increasing nitrogen concentration increased stacking fault energy (SFE) and short-range ordering (SRO), affecting the tensile behavior. Nitrogen addition induced slip planarity and delayed dynamic recovery, leading to an increase in work hardening rate (WHR) at the end of the intermediate deformation stage. At higher strain levels, nitrogen addition suppressed slip line formation and promoted dynamic recovery, accelerating the reduction in WHR. The overall dynamic recovery behavior depended mainly on SRO rather than SFE.