|About this Abstract
|2023 TMS Annual Meeting & Exhibition
|High Performance Steels
|Effect of Nitrogen on the Hardening Mechanisms in the Highly Deformed Steel Rex734
|Manuel Koebrich, Steffen Neumeier, Mathias Göken
|On-Site Speaker (Planned)
Nitrogen alloyed austenitic steels show an excellent trade-off between strength and ductility, as they are reaching very high yield strengths up to 2000 MPa with still sufficient ductility after heavy cold working. Additionally, nitrogen alloyed steels show a strong secondary hardening effect possibly due to elemental segregation after annealing. To understand the hardening effects and especially the role of the interstitial element nitrogen a correlative workflow has been elaborated to characterize the hardening mechanisms for the conventional nitrogen steel Rex734. Stress-strain curves were determined by miniaturized tensile tests, indicating an increased strength for the additional annealed specimen compared to the only deformed condition by Suzuki hardening. The tensile test results were then correlated to the heterogeneous local defect structure by various electron microscopy techniques. Further measurements of the local chemical composition around highly deformed areas by atom probe tomography ultimately reveal the origin of the alloy’s outstanding mechanical properties.
|Other, Mechanical Properties, Characterization