About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
Advances in Ferrous Metallurgy
|
Presentation Title |
Mechanical Behavior and Plasticity Mechanisms of Ultrahigh Strength-high Ductility 1 GPa Low Density Austenitic Steel with Ordered Precipitation Strengthening Phase |
Author(s) |
Craig Guerrero, Devesh K. Misra |
On-Site Speaker (Planned) |
Craig Guerrero |
Abstract Scope |
We describe here the mechanical behavior and plasticity mechanisms of Fe-27Mn-9Al-1C austenitic steel. The experimental steel was characterized by ultimate tensile strength and elongation to fracture of 1125 MPa and 30.8%, respectively. Plastic deformation was accommodated by pronounced planar dislocation slip and characterized by a single planar dislocation glide at low strain and multiple planar slip at high strain. Electron microscopy studies indicated that some of the uniformly distributed ordered kappa carbide precipitates of size ~5–7 nm were sheared by planar glide dislocations during deformation. The planar dislocation glide phenomenon is attributed to the superposition of sheared ordered phase and short range ordering (SRO), which can lead to glide plane softening. Dynamic slip band refinement and shearing of precipitates led to constant strain hardening of austenitic steel. Annealing twin boundaries acted as dislocation source to generate dislocations during deformation, which facilitated sub-division of slip bands and suppressing strain localization. |