|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced High-strength Steels
||Strain Rate Dependence of Tensile and Serration Behaviors of an Austenitic Fe-22Mn-0.7C Twinning-induced Plasticity Steel
||Byoungchul Hwang, Seung-Yong Lee, Sang-In Lee
|On-Site Speaker (Planned)
Effect of strain rate on the tensile and serration behaviors of an austenitic Fe-22Mn-0.7C twinning-induced plasticity steel was investigated in this study. Under slower strain rate range, serrated flow and negative strain-rate dependence of flow stress appeared during tensile testing. The serrated flow is closely related to dynamic strain aging induced by the interaction of dislocation and interstitial carbon. Strain rate jumping test results revealed that the negative strain-rate dependence of flow stress was more dependent on strain hardening rate factor than strain rate sensitivity factor associated with dynamic strain aging. EBSD and TEM analysis showed that higher strain hardening rate at lower strain rate was attributed to the higher fraction and finer thickness of deformation twin. The localized stress accompanied by dynamic strain aging plays an important role in twinning process since it decreases effective stacking fault energy and promotes deformation twinning in localized region at lower strain rate.
||Planned: Supplemental Proceedings volume