|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced High-strength Steels
||G-1: Abnormal Deformation Heating and Dynamic Strain Aging in DP Steels at Forming Relevant Strain Rates and Temperatures
||Mert Efe, Caner Şimşir
|On-Site Speaker (Planned)
Mechanical testing of dual phase (DP) steels at low strain rates (10-3/s) have shown that they are susceptible to dynamic strain aging (DSA) between 100°C - 400°C. In this study, two grades of DP steel (DP590 and DP800) are tested at thermomechanical conditions relevant to forming and the effects of DSA on the formability are established. Infrared thermal imaging (IRT) of both grades at the global and microstructure scale showed abnormal deformation heating at the intermediate strain rates (1 – 10/s). Local temperatures rise up to 200°C, where DSA control the deformation through serrations in the stress-strain curves. With increasing strain rates and temperatures, DSA intensifies and results in severe drops in uniform and total ductility with negative strain rate sensitivity, indicating poor formability at these conditions. The origins of the abnormal heating and DSA mechanisms are explained with a mesoscale model coupled with detailed characterization of the microstructure.
||Planned: Supplemental Proceedings volume