S171 Effect of retained austenite on tensile properties in nitrogen-contained TRIP steel

摘要

Nitrogen is an interstitial element in steel and exhibits a similar tendency to carbon in thermodynamic stabilization of the austenite phase. Previously, we have reported that about 10% of retained austenite has been obtained by intercritical annealing in the ferrite (α) and austenite (γ) two-phase region in the Fe-0.3N alloy [1], and the volume fraction of retained y changes by Mn and Mo addition [2]. In the tensile test of Fe-0.3N steel, the strength-ductility balance depends on the nitrogen content and volume fraction of retained y [3]. In this study, the tensile properties of intercritically annealed Fe-N-X ternary alloys were investigated by comparison with that of Fe-0.3N alloy.