|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced High-strength Steels
||Deformation and Fracture Mechanisms of Ferrite and Austenite Duplex Medium Mn Steels with Various Si Additions
||Binhan Sun, Fateh Fazeli, Colin Scott, Clodualdo Jr Aranas, Baoqi Guo, Stephen Yue
|On-Site Speaker (Planned)
The effect of Si on the mechanical behavior of austenite plus ferrite duplex medium Mn steels depends on the austenite fraction in the intercritical annealed structure. For the lower austenite fraction (~30 %), Si has a significant effect on the uniform elongation, which is related to the influence of Si on the formation of deformation twinning and strain partitioning between austenite and ferrite. Silicon also decreases the post-uniform elongation for this structure. With higher Si contents, the fracture mechanisms change from dimpled-type fracture driven by the nanovoid formation, mainly at the ferrite/strain-induced α’-martensite interfaces, to a combined dimple and cleavage fracture, which is governed by the cracking inside δ-ferrite or along the interface between δ-ferrite and its neighboring phases. Conversely, when the austenite fraction is high (~45 %), the mechanical property is mainly controlled by the transformation-induced plasticity effect and is less sensitive to the Si content.
||Planned: Supplemental Proceedings volume